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S0022369720305813
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The application of hierarchically porous sodium dodecylbenzene sulfonate modified vaterite microspheres for the selective adsorption of toxic cationic dyes has been explored in this work . Hr SMV has been synthesized using a facile and low cost precipitation method . X Ray diffraction Fourier transform infrared Scanning electron microscopy Thermogravimetric analysis and N
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Hr SMV has been synthesized using a facile and low cost precipitation method. Hr SMV exhibits high adsorption efficiencies for toxic cationic dyes. Selective removal of cationic dyes is demonstrated with high separation factors. Mechanism of cationic dyes adsorption on Hr SMV has been discussed.
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S0022369720305850
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Experimental works have shown that decoration of noble metals on the metal oxides significantly increases their sensitivity toward different gases . In this work density functional theory calculations were used to explore the effect of Pd decoration on the sensitivity of a ZnO nanotube toward formaldehyde gas . We showed that the pristine ZnO nanotube physically adsorbs the HCHO gas with adsorption energy of 8.0kcal mol with no impact on the conductivity of ZnO . The response of pristine ZnO nanotube to HCHO gas was calculated to be 0.04 which it was increased to 102.55 by the Pd decoration . The Pd atom catalyzes the following reaction O2 HCHO CO2 H2O by facilitating the OO bond dissociation and passing through an energy barrier of 5.1kcal mol at 298K . This reaction is the origin of the resistivity change of PdZnO nanotube because of the electron donation and back donation processes between the reactants and the ZnO surface . Also a short recovery time of 12ms was predicted for PdZnO nanotube based sensor . The results indicate that the PdZnO nanotube is a promising material for application in the HCHO gas sensors .
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ZnO nanotube physically adsorbs the HCHO gas with adsorption energy of 8.0kcal mol. The response of pristine ZnO nanotube to HCHO gas was calculated to be 0.04. The Pd atom catalyzes the following reaction O. HCHO . CO. H. O. A short recovery time of 12ms was predicted for PdZnO nanotube based sensor. PdZnO nanotube is a promising material for application in the HCHO gas sensors.
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S0022369720305874
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The influence of the armchair and zigzag direction strains on the transport properties through an oscillating silicene electrostatic barrier is theoretically investigated . Our results show that the transmission probability strongly depends on the amplitude of the time oscillating potential and the order of the sidebands . We found that with increasing the amplitude of the time oscillating potential the transmission probability shows an oscillatory evolution and the oscillation amplitude decreases as the amplitude of the time oscillating potential is enhanced . Also the oscillation period decreases monotonically if the strain strength is increased . Due to the evanescent wave the transmission has a gap with respect to the barrier height which widens with an increment in the strain strength . Moreover we calculated the effects of the strain strength on the conductance and found that the conductance shows a strain dependence for both the sidebands and the central band . Finally the possibility of controlling and switching off the currents in silicene using time dependent and site dependent staggered electrostatic potentials are investigated .
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We study transport properties in an oscillating silicene barrier under strain. The transmission with respect to the barrier height has a gap. The transmission probability is sensitive to the sign of the. for the. th sideband. The conductance strongly depends on the strength strain. The conductance exhibits an on off switch effect.
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S002236972030648X
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The binding energy of atoms in substances exceeds the energy of the harmonic vibrator owing to the anharmonicity . Experiments show reduction of the anharmonic component of binding energy in solids under high pressures . These data allow us to determine values of pressures when the coefficients of thermal expansions become equal to zero i.e . when the harmonic phase transition occurs .
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Atomic vibratio energies in solid elements. are determined from force constants and vibration amplitudes. Formation enthalpies of elements at room temperature and 0K differ by more than. due to anharmonicity. . High pressures reduce anharmonicity of atomic vibrations and ultimately make them harmonic harmonic phase transition . For 41 metallic elements we determined the pressures of such transitions.
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S002236972030737X
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This work expresses an equation for polymer tunneling resistivity between adjacent carbon nanotubes in polymer nanocomposites . Two proper models for PCNT conductivity are connected to suggest the tunneling resistivity . The suggested equation expresses the tunneling resistivity by several main terms such as CNT content filler conductivity CNT dimensions CNT curliness percolation onset network portion interphase depth tunneling distance length and tunneling width . The developed models and the suggested equation are used to forecast the conductivity and tunneling resistivity in various samples . Furthermore all parameters significances on the tunneling resistivity are justified . The tunneling resistivity of samples decreases by increment of CNT concentration but high filler contents cause the slight variation of tunneling resistivity . Moreover low percolation onset dense interphase slight waviness high filler conductivity high fraction of networks and short tunneling space weaken the tunneling resistivity . The differences in the tunneling possessions significantly change the tunneling resistivity from 0 to 2500m while the wettability of filler by polymer medium insignificantly manipulates the tunneling resistivity .
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We express an equation for polymer tunneling resistivity in polymer CNT nanocomposites. The suggested equation considers CNT network interphase and tunneling properties. All parameters significances on the tunneling resistivity are justified. The tunneling resistivity of samples decreases by increment of CNT concentration. Dense interphase large networks and short tunneling space weaken the tunneling resistivity.
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S0022369720307447
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The porous Co based spinel composite oxides containing different transition metals were prepared by soft template method for ethanol complete oxidation in air . The physicochemical properties of the prepared oxides were characterized by XRD BET H
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Porous Co based spinel oxide can be synthesized by soft template method. The physicochemical properties of Co based spinel oxide can be effected by transition metal. Porous Co based spinel oxide has high ethanol complete oxidation activity at low temperature. Catalytic activity is related to the pore structure and surface reactive oxygen species.
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S0022369720308167
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In this study pure and Al doped CuO nanoparticles has been synthesized using the solution combustion technique . The effect of the Al dopant on the structural surface morphological optical and electronic properties of the CuO NPs was studied . The crystalline structure of the NPs has been studied by X ray diffraction analysis . XRD studies indicate that the NPs produced are highly crystalline with tenorite phase . Al doping was found to modify the bond length and lattice strain of the CuO NPs . The surface morphology of the NPs showed formation of spherical particles for lower Al doping while at higher doping concentration agglomeration of NPs occurs and the particle size changes . A reduction in the optical band gap of the NPs was observed due to Al doping and such a red shift in the band gap can be attributed to incorporation of the Al
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Pure and Al doped CuO nanoparticles NPs has been synthesized using solution combustion technique. Al doping modify the structural parameters together with bond length lattice strain and atomic distance of the CuO NPs. Surface morphology of the NPs showed formation of spherical particles for lower Al doping while at higher doping concentration agglomeration of NPs. The optical band gap of the CuO NPs reduces due to Al doping. First principles calculations based on density functional theory DFT study reveal creation of an impurity level is created within the energy gap of the NPs due to Al doping resulting in a reduction in band gap.
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S0022369720308180
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In the present study iron reinforced novel composite materials were produced as alternative shielding materials . In this context linear attenuation coefficients and mass attenuation coefficients half and tenth value layers mean free path and effective atomic number were determined . An experimental gamma ray transmission setup was utilized for determination of MAC values . To confirm the consistency of experimental results the obtained MAC values were compared with those produced using the WinXcom program and MCNPX Monte Carlo code . Moreover exposure buildup factors and energy absorption buildup factors were calculated using a geometric progression fitting method . Relative dose distribution values of fabricated samples were calculated at 5 10 and 20 MFP penetration depths up to 10MeV . In addition to gamma ray attenuation properties basic interaction parameters of charged particles such as protons and alpha mass stopping powers alpha projected ranges and proton projected ranges were determined in the 0.01515MeV energy range . Finally variation of fast neutron removal cross section versus increasing Fe concentration in composites was investigated . The composite with the highest Fe addition showed the best shielding capacity for gamma radiation .
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Iron Fe reinforced novel composite materials were produced. An experimental gamma ray transmission setup was utilized for determination of MAC values. EBF and EABF calculated using geometric progression fitting. MAC values were compared with WinXcom program and MCNPX Monte Carlo code. Fe 20 with the highest Fe addition had the best gamma ray radiation shielding capacity.
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S0022369720308428
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Molecular dynamics simulations have been employed to simulate the deposition process of Cu and Ni atoms on the Ni substrate with the different compositions in the Cu
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As Cu content in Cu. Ni. film rises the lattice constant of deposited CuNi film increases. The high shear strain area of the Cu. Ni. Ni substrate propagates to interface in the indentation process. The force hardness of Cu. Ni. Ni substrate decreases as increasing the content Cu and temperature. The force hardness of Cu. Ni. Ni substrate increases as increasing the loading velocity. The dislocations density increases as increasing the temperature and the loading velocity.
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S0022369720308441
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Palladium chloride and chlorinated poly mixture were prepared into homogeneous solution followed by electrospinning to make uniform nanofibers with average diameter of 460nm . Then these composite nanofibers were treated in ethylenediamine solution to functionalize and crosslink the CPVC molecules inside the nanofibers to improve their chelating ability and solvent resistance . The functionalization and crosslinking of CPVC molecules inside composite nanofibers were confirmed by SEM FT IR EA and PALS characterizations . The catalytic performance of these palladium encapsulated CPVC nanofibers
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Pd nanoparticles were generated in crosslinked and aminated CPVC nanofibers. Pd nanoparticles were stabilized by chelating and capping effects. These nanofibers exhibited high activity and stability for coupling reactions. The activity decay was resolved by PALS and other common characterizations
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S0022369720308453
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In the wake of blue phosphorenes theoretical prediction and experimental synthesis it has emerged as an excellent candidate for anode materials in alkali metal ion batteries due to its outstanding electrochemical performance . In the work we have addressed the impact of edge passivation by both hydrogen and oxygen atoms on single adsorption of different alkali metal atoms over zigzag blue phosphorene nanoribbons using first principles calculations . Our results unravel that in the presence of edge H passivation the nanoribbon binds alkali metal atoms inferior to the pristine blue phosphorene with binding energies varying from
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The favorable binding of single alkali metal atoms is sensitive to the type of edge passivated atoms. Single adsorption of alkali metal atoms may affect the nanoribbons electronic and magnetic properties. The optimized edge passivation is promising for use in rechargeable metal ion battery technology.
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S0022369720308751
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The development of multicomponent Al Bi alloys is an alternative approach to control either separation or morphology of the phases forming their microstructures . Furthermore addition of alloying elements in Al Bi alloys has been settled to pursue an optimized combination of wear resistance and mechanical strength . In the present investigation solidification conditions are deduced from temperature measurements and the microstructure is thoroughly characterized . The results highlight the impact of the solidification conditions on the Bi distribution and macrosegregation . A relation is established between Bi droplet spacing and wear resistance and a comparison with previous experiments on Al Bi Cu alloys is outlined . It is found that both Bi segregation and spacing between globules of Bi control the wear resistance of the Zn containing alloy . Despite the similarities of Bi spacings if Cu and Zn containing alloys are compared the wear resistance of the Cu containing alloy is higher .
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Cooling rates higher than 5K s and Bi segregation produced unchanged Bi spacing. Microstructure is formed by Bi globules and lamellar AlFeSi particles within Al. A single wear performance relationship was proposed. Superior wear property was found for the Al Bi Cu if compared with the Al Bi Zn alloy.
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S0022369720308787
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Surface thermodynamic properties related to nanoparticles size and morphology generate significant influences on their thermodynamic behaviors in different physicochemical processes . Herein the electrode potentials of Ag nanoelectrodes formed with various particle sizes and morphologies of nano Ag were determined at varying temperatures . Based on the method of electrochemistry the surface thermodynamic properties of nano Ag were gotten and a comparison was made with theoretical results . It is revealed that with decreasing nano Ag size these surface thermodynamic properties become larger and correlate linearly with inverse particle size . Furthermore for nanoparticles with the same equivalent size the change regularity of surface Gibbs energy enthalpy and entropy with morphology follow the same sequence as cube sphere wire . This study is valuable to provide insights to the influence mechanisms and regularities of nanoparticle size and morphology on these properties .
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The method of obtaining surface thermodynamic properties of nanoparticles by electrochemistry was proposed. Quantitative influence regularities of particle size and morphology on these properties of nano Ag were investigated. Experimental results on the surface thermodynamic properties of nano Ag agree with theoretical predictions.
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S0022369720309963
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We investigated the heat capacity and thermal conductivity of UN using first principles methods . The generalized gradient approximation of the Perdew Burke and Ernzerhof functional developed for solids as implemented in Quantum ESPRESSO and associated codes was used . We evaluated the energy of the UN to be lower for ferromagnetic ordering than non magnetic . We found using QE code that the lattice constant calculated using PBEsol functional and norm conserving pseudopotentials is slightly larger for ferromagnetic UN than non magnetic UN and they agree with experiment . We noted a significant contribution from the optical phonons to the lattice thermal conductivity which was previously observed experimentally for urania . The phonons calculated contribution to the thermal conductivity which decreases with temperature is smaller at room temperature 7.20 Wm
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We demonstrated that first principles calculations predict heat capacity and thermal conductivity in UN qualitatively. The new GGA PBEsol functional predicted structural properties of UN in a good agreement with experiment. We foundthat only the frequencies of optical phonons are affected by the presence of magnetic moment on uranium atoms. The calculated electrical resistivity of nonmagnetic UN at low temperature is lower than measured and is resembling ThN. Predicted electronic thermal conductivity remained significant at higher temperatures as required for a safer nuclear fuel.
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S0022369720310477
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Solid nitrogen has received widespread attention . In this paper the calculated structural electronic phonon and mechanical properties are used to investigate the phase transition of solid nitrogen space group P4
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First principles calculated phonons of tetragonal solid nitrogen under pressure. Negative group velocity is considered to be the structural phase transition velocity. The phase transition starts at a b axis along. direction.
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S0022369720310490
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In this study we reported the preparation of polyamidoamine modified magnetite nanoparticles and their use for the immobilization of Fe salen complex to form a novel magnetic catalyst . The prepared catalyst was characterized by some modern techniques i.e . Fourier transform infrared spectroscopy thermogravimetric analysis N
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A novel catalyst based on salen iron complex immobilized on dendrimer magnetite nanoparticles was synthesized. The catalyst was applied as a recyclable catalyst for the oxidation of sulfides. The catalyst could be recycled up to five cycles without significant decrease in catalytic activity and selectivity.
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S0022369720310829
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Alkali metal doped strontium meta silicate a highly conductive system is being studied as an alternative to solid electrolyte for Solid Oxide Fuel Cells . Its high electrical conductivity is attributed to its structure and dopant strategies . Based on the recent reports it was observed that it can exist in multiple forms depending upon synthesis route and conditions . The present study deals with the analysis of polymorphism inside strontium meta silicate SrSiO
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Monomer and Trimer Strontium meta silicate SrSiO. was prepared via solid state reaction route. Polymorphic phase formation of SrSiO. system was studied through Rietveld refinement analysis. The co existence of polymorph of Monoclinic trigonal and triclinic in SrSiO. is reported for the first time. The electrical conductivity studies were performed for both monomeric and trimeric SrSiO. system. The conductivity enhancement is observed due to the mutual variation of polymorphic phase content in SrSiO
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S0022369720310982
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Graphene oxide is considered as a toxic carbon material and the adverse impact of GO has been realized . Herein the spherical chitosan modified silicon dioxide CS SiO
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The removal of GO on CS SiO. was dependent on pH and ionic strength. The removal capacity of CS SiO. for GO was 111.8mg g. The elimination of GO relied on the electrostatic attraction and hydrogen bond.
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S0022369720311902
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In the present study we employ spin polarized density functional theory for examining changes in the opto electronic properties of wide band gap barium zirconate by incorporating Vanadium and Phosphorous dopants at Zr and O sites of BaZrO
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DFT calculations for Vanadium and Phosphorous doping in BaZrO. are reported using PBE GGA and mBJLDA functionals. Structural energetic electronic and optical properties of the pristine mono doped and co doped systems are explored. Introduction of P. and V. states in electronic structure of BaZrO. reduce the large band gap of this material. Improved absorption of V P doped BaZrO. in the visible and UV region makes it suitable for photocatalysis applications.
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S0022369720316309
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The paper published by W. Wang B.P . Lin Y. Cao Y . Sun X.Q . Zhang H. Yang H. Sun entitled High performance Gd
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Comments on a published paper were presented. The published paper is on porous nanofiber processing. Figure caption corrections on the original paper were suggested.
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S0022407318306605
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To evaluate characteristics of the low lying electronic states and the feasibility of the laser cooling of the AuH molecule we investigate the potential energy curves the vibrational and rotational characteristics of the ground and low lying excited electronic states based on
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The optical laser cooling scheme is suggested for AuH. The cooling effect is evaluated with Einstein coefficient and recoil temperature. The potential energy curves of ten electronic states of AuH molecule are obtained. The spectroscopic parameters the rovibrational energy levels are determined. The FranckCondon and transition dipole moments are calculated for the states.
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S0022407318309324
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Electromagnetic radiation within the Earth atmosphere system is inherently of three dimensional nature . To quantitatively investigate the various 3D radiative effects in arbitrary spatial resolution the backward Monte Carlo approach provides an efficient and flexible technique . In this paper a new importance sampling scheme of 3D backward Monte Carlo radiative transfer is introduced as Light Estimator Including Polarization Surface Inhomogeneities and Clouds code
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A new variance reduction technique of backward Monte Carlo MC radiative transfer the Separated Near Solar Local Estimation SNSLE method is proposed and implemented in the new 3D MC radiative transfer code called the Light Estimator Including Polarization Surface Inhomogeneities and Clouds LEIPSIC . The LEIPSIC code includes the abilities to handle 3D cloud fields and 2D albedo DEM maps polarized scalar scattering solar thermal radiation radiance irradiance calculation spectrum integration using the REPTRAN approach and parallel computing. The code is published as an opensource project at https gitee.com BinLeipzig LEIPSIC. The efficiency and accuracy of the LEIPSIC code are validated against the benchmark results of spectral radiances and broadband irradiances. Two applications of the broadband solar 0.32.5 micron cloud radiative forcing CRF is simulated for the typical Arctic scenarios. The 3D and 1D independent column approximation ICA results are compared in order to show the abilities and limits of the commonly used ICA approach.
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S0022407319301906
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Hot spots have been considered as a dominant role in surface enhancement Raman scattering . Here we investigated the size and shape effect of Ag nanocubes in surface plasmon response and SERS by both experiment and theory simulation method . Silver nanocubes with abundant hot spots were synthesized by a polyol method and utilized as electrodes for achieving high SERS enhancement . The absorption wavelengths of the nanocubes were tunable by changing the edge lengths of the nanoparticles . Finite difference time domain simulations were employed to investigate the local E field generation around silver nanocubes indicating remarkable E field enhancement at the edges and vertexes known as hot spots . Then the SERS analyses demonstrated that the SERS activity of various Ag nanocubes using crystal violet as probe molecules showed a significant enhancement . The enhancement factors of SERS show strong sensitivity between the nanoparticle size and shape . Moreover the enhancement for CV on Ag nanocubes was significantly higher than for Ag nanospheres . Therefore the stable and high performance of Ag nanocubes SERS system shows great application prospects in both scientific researches and practical application .
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Ag nanocubes with tunable edge lengths have been successfully synthesized. The E field intensity at the Ag cube edges and vertexes is significantly enhanced. Ag nanocubes exhibited a much higher SERS performance compared with Ag nanospheres. The size and shape effects of Ag nanocubes were investigated.
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S0022407319302080
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The discrete dipole approximation is a popular numerical method for electromagnetic scattering calculations . The standard DDA formulation involves the uniform discretization of the underlying volume integral equation leading to a linear system of convolution form . This permits a matrix vector product to be performed with
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A preconditioner for scattering simulations with the discrete dipole approximation. The Toeplitz DDA matrix is approximated by a circulant for preconditioning. Order of magnitude accelerations are observed for hexagonal ice prisms. Algorithms are described so the preconditioner can be used in readers own codes.
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S0022407319302328
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Black carbon aerosols have substantial effects on the climate whereas there still are significant uncertainties on coated BC radiative properties . Numerical investigations on radiative properties of polydisperse BC aggregates partially coated by non absorbing organics which are calculated by the exact multiple sphere T matrix method are presented . The objective of our study is to evaluate the impacts of particle microphysics including BC coating volume fraction shell core ratio BC morphology and size distribution on partially coated BC radiative properties as well as their absorption and scattering enhancements . Particle size distribution and shell core ratio affect radiative properties of partially coated BC significantly while BC coating volume fraction is an insensitive parameter . The absorption enhancement of BC particles due to partially coated by organics varies from 1.0 to 2.0 whereas their scattering enhancement can reach up to 100 . The BC coating volume fraction seems to be responsible for BC absorption enhancement and with BC coating volume fraction becoming larger the absorption enhancement becomes more sensitive to particle size distribution and shell core ratio . However the dependence of BC scattering enhancement on shell core ratio is larger than size distribution and BC coating volume fraction and the dependences of scattering enhancement to size distribution and BC coating volume fraction becomes stronger as shell core ratio becomes larger . Our study gives a further understanding of the influences of particle microphysics on partially coated BC radiative properties and it may be helpful for model and parameter simplifications .
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Radiative properties of coated BC are numerically studied with recent observations. The importance of coating microphysics on aged BC radiative properties is stressed. Scattering and absorption enhancements of BC due to partial coating are studied. Shell core ratio and size distribution are highlighted for BC radiative properties.
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S0022407319302365
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Physics based forward models are the basis on which many experimental diagnostics are interpreted . For some diagnostics models can be computationally expensive which precludes their use in real time analysis . Reduced models have the potential to capture sufficient physics thereby enabling the desired real time analysis . Using statistical inference and machine learning techniques the application of reduced models for inversion of atomic spectral data used to diagnose magnetic fields in a plasma will be examined . Two approaches are considered a reduction of the forward model where traditional inversion can be performed on the proxy model and a reduction of the direct inverse where parameters are a function of measured signal . The resulting inversion is sufficiently fast to be utilized in an online context for digital twinning and ultimately real time prediction design and control of plasma systems such as tokamaks . These methods will be demonstrated on both simulated and experimentally measured data .
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Machine learning finds a model when no physics based model exists. Using ML methods reduced forward and direct inverse models can be obtained. Models trained using idealized data predict well when applied to experiment.
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S0022407319303073
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Based on the Mie Scattering Theory and the Dense Medium Radiative Transfer Theory this paper analyze the electromagnetic scattering properties of particles under different humidity and temperature and discusse the polarization brightness temperature of moist granular layer . The numerical calculation results show that when the particle temperature is over 273K the particle humidity has more obviously influence on the electromagnetic scattering properties of sand particles than its temperature . When the temperature is below 273K the optical properties of particles are mainly affected by the humidity of particles and with the increase of humidity the extinction efficiency of particle shows a trend of increasing initially and decreasing afterwards and the maximum value appears when the humidity of the wet ice is 0.2 . In addition with the increase of particle temperature and humidity the microwave brightness temperature of particle layer significantly increases and its vertical polarization brightness temperature is greater than the horizontal polarization brightness temperature the maximum difference appears near the observation angle of 55 . However it is more sensitive to the thickness of sand layer when the observation angle is below 30 and the thickness does not exceed 30cm .
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The electromagnetic scattering properties of moist particles in different temperature is discussed. Microwave emission of moist granular layer is discussed by the Dense Medium Radiative Transfer Theory. The influence of the thickness and humidity of the moist granular layer on the brightness temperatures is discussed.
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S0022407319303188
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In this study the propagation of polarized light in anisotropic media composed of prolate ellipsoids oriented in the same direction is investigated . We proposed a DDA Monte Carlo combined algorithm to solve the radiative transfer problem . By comparisons of backscattering two dimensional images of Mueller matrix the results show that the changing information of aspect ratio and orientation of ellipsoidal scatterers can be well encoded in image based Mueller matrix . Moreover the effect of aspect ratio and orientation on diattenuation retardance depolarization and linear retardance are demonstrated by decomposing the Mueller matrix . Furthermore the impact ofaspect ratio on the rate of depolarization of linearly and circularly polarized light with optical thickness has been construed . This study has proved that structural anisotropy decelerates the depolarization rate of scattering light and traditional diffusion theory can not be used to solve polarized light transport in anisotropic media . Our study can promote a further research on the physics of radiative transfer in anisotropic media .
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Variations in image based Mueller matrix encode information about the aspect ratio and orientation of ellipsoidal scatterers. The rate of depolarization depends on the incident polarization state scattering orders and the anisotropy of the random medium. Structural anisotropy decelerates the depolarization rate of scattering light. Structural anisotropy has different effects on depolarization of circularly polarized incidence and linearly polarized incidence. Traditional diffusion theory cannot be used to solve polarized light transport in anisotropic media.
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S0022407319303218
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In this study Hapke s radiative transfer model is used to verify the feasibility of retrieving the composition and grain size of the ground in an open pit mine seen as a regolith . Such a tool could be useful for dust surveys and thus preventing potential environmental risks such as acid mine drainage . As the true compositional endmembers of the medium are not retrieved but rather chosen from spectral libraries and the range of grain sizes and porosities vary greatly in an open pit mine we show that the mineralogical unmixing results are not reliable . Too many combinations of different relative abundances grain sizes and porosities lead to fits between modelled and measured spectra under 0.3 in reflectance . To tackle this issue we explore a lithological unmixing approach . Considering lithologies as endmembers as opposed to considering minerals reduces the variability in the solutions as fewer endmembers are used . The results show that the studied samples with multi component grains behave spectrally as expected for mono mineral grains . With no root mean square errors higher than 5 the relative abundances retrieved are sufficiently precise to consider mapping lithologies with this method .
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An open pit mine can be seen as a regolith. A mineralogical segregation occurs during the crushing sieving process. RMSEs are not discriminant to retrieve minerals relative abundances. Considering lithologies as pure endmembers is a valid assumption.
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S0022407319303334
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The electromagnetic wave transmittance in sand dust storms is studied via Monte Carlo simulation and the effect of charged particles and multiple scattering processes on the EMW transmittance attenuation in sand dust storms is studied . Based on Monte Carlo simulation the electromagnetic wave propagating in a sand dust storm is treated as Monte Carlo photon packets which are randomly scattered by sand dust particles . The MC simulation results show that neglecting the multiple scattering effect could result in significant error in the theoretical evaluation of EMW transmittance attenuation in sand dust storms especially at high frequency bands and under low visibility conditions . As the sand particles are charged this error could be enlarged further . Compared with the effect of charged particles on the attenuation of EMWs the effect of multiple scattering processes is more significant . On the other hand when the multiple scattering processes are considered in the calculation of EMW transmittance attenuation the effect of charged particles on the calculation results will be significant for the cases of low frequencies and small particle sizes .
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Multiple scattering studied by Monte Carlo simulation in charged granular system. Multiple scattering can t be ignored when particles carry net charges on its surface. Obtaining threshold visibility considered multiple scattering in charged granular system. Multiple scattering is related to visibility and propagation distance. Multiple scattering is influenced by size parameter and surface charge density.
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S0022407319303346
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In spite of the enormous progress in electromagnetic scattering since Mie subsequent theories assume that particle optical properties are not perturbed by surface currents . Given that the premise remained largely unexamined major concerns were raised after preliminary results obtained very recently for a charged spherical particle showed that it resonates with the EM radiation in a wide range of modes . The mechanism of this phenomenon is still poorly described for idealized particle models and completely unknown for arbitrarily shaped particle aggregates .
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Excess charge EC initiates unexpectedly amplified optical resonances in nanoparticles. EC can have significant consequences for the optical characterization of particle systems. Charge controlled resonances can be used in novel optical devices. The conductivity models for non spherical particles remain unexplored until now.
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S0022407319303449
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This research introduces the evolution strategy based on covariance matrix adaption algorithm which has been proven applicable for solving highly inseparable and nonlinear optimization problems to resolve the nonlinear tomography absorption spectroscopy inverse optimization problem and simultaneously reconstruct a two dimensional temperature and species concentration distribution fields in an absorption flame . Severe ill posedness and crosstalk issues exist during multi parameter field simultaneous reconstruction . To alleviate the ill posedness in nonlinear tomography absorption spectroscopy equations two regularization methods Tikhonov regularization and the regularization based on the generalized Gaussian Markov random field are applied to reconstruct the temperature distribution field . The impacts of different regularization factors are investigated as well and optimal intervals are suggested for reference . Simulation results show that the evolution strategy based on covariance matrix adaption algorithm worked well in retrieving multi parameter distribution fields on both symmetric and asymmetric flame distribution models . Moreover the evolution strategy based on covariance matrix adaption algorithm alleviated the severe crosstalk issue between temperature and species concentration to improve the accuracy of the reconstructed species concentration distribution field .
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Simultaneous measurement of temperature and concentration is investigated. The CMA ES algorithm is introduced to solve the inverse problem. Tikhonov regularization can improve the reconstruction quality.
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S0022407319303553
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The interaction of an axicon generated vector Bessel beam with a charged sphere is investigated in the framework of generalized LorenzMie theory . The incident internal and scattered fields are expanded using vector spherical wave functions beam shape coefficients and internal and scattered coefficients . An analytical expressions of beam shape coefficients which are derived using angular spectrum decomposition method are given . The internal and scattered coefficients are derived by considering the boundary conditions . The internal and near surface electric fields of a charged sphere illuminated by AVGBBs are numerical calculated and the effects of polarization order of beam half cone angle are mainly discussed . The results are compared with that for neutral particles . The effect of the surface charge are discussed by the comparison of the results for charged spheres with that for neutral particles . Numerical results show that the internal and near surface fields are sensitive to the surface charge . The internal fields and the near surface fields can be locally enhanced . Internal and near surface fields especially its local enhancement are very sensitive to the beam parameters including polarization order half cone angle etc .
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The internal and near surface fields for a charged sphere by a vector Bessel beam is investigated in the framework of GLMT. The effects of the surface charge polarization order and half cone angle are discussed. The local enhancements of internal and near surface fields are analyzed.
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S002240731930367X
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When the size of scattering particle is increased to be comparable with wavelength Rayleigh approximation becomes not valid . In polarization scattering pattern this quasi rayleigh behavior manifests itself as a sharp drop of the degree of linear polarization to the negative values . In this paper we studied the properties and features of this quasi rayleigh polarization leap for monodisperse spherical scatterers . The main regularities that determine the wavelength position of the quasi rayleigh polarization leap are established depending on the phase angle refractive index and size parameter of the scatterers . A method is suggested for determining the radius of spherical scattering particles of the polystyrene beads in Earth s atmosphere . A simple interpolation formula is given which allows based on observational data such as phase angle and the wavelength at which the quasi rayleigh polarization leap is observed to calculate the particle radius .
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When the size of Rayleigh particle is increased there is a sharp drop of the degree of linear polarization to the negative values. Mie theory was used to study the main properties of this feature called quasi rayleigh polarization leap. Quasi rayleigh polarization leap depends on the phase angle refractive index wavelength and radius of the monodisperse spherical scattering particle. A method for determining the radius of monodisperse spherical scattering particles using quasi rayleigh polarization leap properties is suggested. A simple interpolation formula to calculate the particle radius of the polystyrene beads in Earth s atmosphere is given.
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S0022407319304066
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An analytical method of analyzing the electromagnetic scattering of a Gaussian beam by an infinitely long circular cylinder with a spherical inclusion is presented . The fields within different regions are expanded in terms of appropriate cylindrical or spherical vector wave functions . By applying the integral representation of spherical vector wave functions over cylindrical ones boundary conditions and projection procedure the unknown expansion coefficients are determined . For a localized beam model numerical results of the total scattered field and normalized field intensity distribution are shown and the scattering properties are discussed briefly .
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Gaussian beam scattering by a sphere embedded in an infinitely long circular cylinder is presented. The projection method is applied to the scattering problem. Total scattered field and normalized field intensity distribution are calculated.
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S0022407319304091
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In this work we extend earlier findings that optically small and randomly oriented ovaloids extinguish more radiation than equal volume spheres to differential cross sections . Rather than working with the normalized phase function as is typically done in radiative transfer and in remote sensing we compute absolute
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At each angle optically moderate ellipsoids scatter more than equal volume spheres. Increase in absolute scattering cross section is monotonic with aspect ratio. Spherical shape optimality holds for absorption cross sections as well. Ice and quartz serve as examples to illustrate relevance to remote sensing.
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S002240731930411X
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The Monte Carlo method is the most accurate method for resolving radiative heat transfer in participating media . However it is also computationally prohibitive in large scale simulations . To alleviate this this study proposes a quasi Monte Carlo method for thermal radiation in participating media with a focus on combustion related problems . The QMC method employs low discrepancy sequences in place of the traditional random numbers . Three different low discrepancy sequences Sobol Halton and Niederreiter were examined as part of this work . The developed QMC method was first validated against analytical solutions of radiative heat transfer in several one dimensional configurations . Then it was extended to three dimensional practical combustion configurations . The results from QMC and traditional Monte Carlo are compared against benchmark solutions for each cases . It is shown that the error of the predicted radiation field from QMC is lower than an equivalent MC simulation . The computational cost of QMC was also found lower than MC due to the avoidance of requirement of several statistical runs for traditional Monte Carlo methods alongside achieving the reduction in error . In conclusion significant improvements in computational costs and accuracy seen in the QMC method makes it an attractive alternative to traditional Monte Carlo methods in high fidelity simulations .
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A quasi Monte Carlo QMC method using low discrepancy sequences for thermal radiation transport is proposed. Three low discrepancy sequences Sobol Halton and Niederreiter were tested and found to have comparable accuracy. The accuracy of QMC method was systematically evaluated in a series of one dimensional and three dimensional combustion relevant configurations. The QMC method was found to have lower error and faster convergence rate than conventional Monte Carlo method for thermal radiation. A figure of merit defined from combination of computational cost and accuracy showed QMC to be significantly more advantageous than conventional Monte Carlo method for thermal radiation.
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S0022407319304248
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Phenomenological radiative transfer models commonly assume that particles in media reside in each others far zone and thus are defined by their single scattering properties . This so called far field assumption becomes questionable for dense particulate snow layers since the location of the snow grains inside is close and in each others near zone . Electromagnetic interactions among the particles can occur which potentially change their single scattering properties . In this paper the near field effects in radiative transfer simulations of the snow surface bidirectional reflectance factor and the albedo of a snow layer in the wavelength range of 300 2500nm are investigated using the phenomenological radiative transfer model SCIATRAN . The snow layer is composed of densely packed snow grains of droxtal shape with a maximum dimension of 60m . The snow grain shape assumption is justified by the good agreement of the simulated top of atmosphere BRF with satellite measurements over a pure snow surface in Greenland . To evaluate the error of the far field assumption the single scattering properties of the dense particulate snow layer has been modified according to the dense medium light scattering theory . By applying the far field approximation the BRF is overestimated by less than 0.039 at forward scattering angles and underestimated by less than 0.006 at backscattering angles respectively . The albedo of the dense particulate snow layer is overestimated by less than 0.012 . In the considered case the near field effects on the snow surface BRF and the albedo of radiative transfer simulations appear negligibly small . Consequently the simulation of snow surface BRF and albedo in the wavelength range of 300 2500nm by phenomenological radiative transfer models under the far field assumption is well justified .
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The far field assumption is evaluated for a dense particulate snow layer. The impact of near field effects on simulated snow BRF and albedo is estimated. Droxtals satisfactorily describe the reflection properties of a natural snow layer. The near field effects in snow are negligibly small. The simulation of snow BRF and albedo under the far field assumption is justified.
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S0022407319304315
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We report the production of ultracold heteronuclear NaCs molecules in excited electronic states by photoassociation of ultracold Na and Cs atoms . The saturation of the photoassociation scattering probability is observed from the dependence of the trap loss probability on the photoassociation laser intensity . Based on the scattering theory we estimate the saturation intensity of photoassociation which is deduced by fitting the experimental data to a saturation model .
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High resolution spectroscopy of. state in long range part of ultracold polar NaCs molecules. The saturation effect was observed in the polar molecules system. The saturation of the photoassociation scattering probability is demonstrated from the dependence of the trap loss probability on the photoassociation laser intensity. The saturation intensity is deduced from the theory and corresponding well to the experimental data.
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S0022407319304467
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Leaf chlorophyll content is an important indicator of plant physiological status photosynthetic capacity plant stress and senescence . Optical reflection measurements offer a nondestructive method for estimating LCC and have been widely used in plant science and ecological applications . Light reflected from leaves surfaces can be described by photometric and polarimetric measurements . In this study previously introduced spectral indices based on photometric measurements did not yield highly accurate estimates of LCC using multi angular measurement in the forward scattering directions . Subsequently an index derived from photometric measurements the bidirectional reflectance factor and some previously introduced spectral indices based on the degree of linear polarization were used to estimate LCC . We found that a newly proposed spectral index based on BRF and 1 DOLP allowed the convenient estimation of LCC with a high accuracy explaining more than 90 of LCC variation . The method which relates LCC to the BRF and 1 DOLP of leaves using multi angular measurements indicates that both photometric and polarimetric properties are effective for LCC estimation . This study opens the possibility for estimating LCC based on polarization reflected from leaves . One advantage of using polarization to remotely sense leaf biochemical parameter is that DOLP measurements do not need to be normalized by a reference panel as BRF measurements .
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Variation of chlorophyll content changed the spectral degree of linear polarization DOLP of leaves as the photometric measurements. Spectral indices expressed in terms of DOLP were able to estimate leaf chlorophyll content at different directions dominated by specular reflection. The spectral DOLP and BRF indices have the potential to be used for LCC estimation under laboratory and field conditions.
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S0022407319304480
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Temperature dependences of molecular line shape parameters are important for the spectroscopic studies of the atmospheres of the Earth and other planets . A number of analytical functions have been proposed as candidates that may approximate the actual temperature dependences of the line shape parameters . In this article we use our
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Ab initio quantum scattering calculations. Temperature dependences of the pressure broadening pressure shift speed dependence and the complex Dicke parameter. Comparison of the four temperature ranges 4TR and double power law DPL temperature dependence models. Hartmann Tran profile HTP parameterization.
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S0022407319304509
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Absorption efficiency profiles and localized surface plasmon resonance wavelengths are reported for metallic core shell nanoparticles placed over a BK7 glass substrate . A numerical study is performed with the vectorized version of the discrete dipole approximation with surface interactions . Gold and silver metallic components are used for the simulations of two different core shell structures . Absorption enhancement and the hybrid modes of plasmon resonances of the core shell structures are compared by using a measure that defines a size configuration . It is observed that a small volume fraction of the core sizes results in shell domination over the plasmon response . An additional study is conducted to discern the sensitivity of the refractive index of nanoparticles in different surrounding environments . With a selected core shell size configuration of Ag Au pairs a significant absorption enhancement with a redshift of LSPR wavelength is observed for both Ag core Au shell and Au core Ag shell NPs . The absorption behavior of the bare metallic NPs and selected core shell pairs in proximity to an external probe s tip is also analyzed . The gallium phosphide and silicon tip usage are investigated with transverse electric and transverse magnetic wave polarizations . It is observed that the dominance of light polarization on the absorption enhancement of the NPs switches at different wavelengths where the dielectric transition for tip materials occurs . These findings show the possible targeted uses of metallic core shell nanoparticles in several areas such as nanomanufacturing localized heating bio sensing and material detection applications .
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Plasmonic responses of core shell nanoparticles on a substrate are investigated. Bimetallic pairs are considered for absorption enhancement and sensing. Near field coupling between the nanoparticle and AFM tip investigated. Dielectric transition of AFM tip materials is analyzed for the absorption mechanism. DDA SI v is used for calculating the interactions with an evanescent wave.
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S0022407319304613
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We present a hybrid radiative transfer geometric optics approximation to model multiple light scattering in arbitrary finite discrete random media in the geometric optics regime . In the hybrid model the medium is divided into a mantle composed of discrete particles and into a diffusely scattering core . In the mantle multiple scattering is handled by using a ray tracing algorithm with the generalized Snels law for inhomogeneous waves whereas in the core ray tracing with diffuse scatterers is incorporated to approximate multiple scattering and absorption . The extinction distances required to compute the scattering in the core are derived numerically by tracing the distances of the scattering and absorption events instead of using the classical extinction mean free path length . We have written a new framework that can treat arbitrary meshes consisting of watertight surface meshes with multiple diffuse scatterers and refractive indices . Comparison between the ground truth obtained from pure geometric optics ray tracing the solutions obtained by using radiative transfer and the hybrid model show that the hybrid model can produce better results particularly if a densely packed medium is studied . In the future the new approximation could be used to solve light scattering from larger media such as asteroid surfaces that are out of reach for the pure geometric optics methods due to their computational complexity .
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Modelling can be improved by mixing the geometric optics and the radiative transfer. Extinction distances improve the phase function but not that well the other scattering elements. Surface structure is mandatory for a densely packed medium.
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S0022407319304649
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In this study we use an artificial neural network method to estimate the downward surface shortwave radiation over China from Himawari 8 geostationary satellite data . As the training data of the DSSR estimation algorithm ground observed DSSR data is compiled to complete the ANN method . GOS data from 89 stations over mainland China in 2016 are divided into training testing and validation samples with a proportion of 3 1 1 in order to perform the DSSR estimation and accuracy validation . As a result estimated DSSR from Himawari 8 data in 2016 shows good consistency with validation samples of ground observed DSSR holding the determination coefficient and root mean square error of 0.90 and 88.86Wm
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The ANN algorithm model can quickly and accurately calculate the hourly SSR by directly connect the satellite data and in situ SSR measurements in a simple way rather than the complex scheme based on the lookup table estimation approach. The ANN model was applied to Himawari 8 geostationary satellite data and the estimated SSR show a good agreement with in situ observation. We analyze the spatio temporal characteristics of SSR in China on the hourly daily and monthly scale in 2016. The previous studies have less to analyze the characteristics of SSR spatio temporal at the daily scale especially at the hourly scale.
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S0022407319304674
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A new experimental methodology to simultaneously measure gas temperature and boundary layer thickness was developed and explained for the first time in this work . The new methodology is based on the line of sight broadband filtered natural infrared emission of species and it solves one of the main challenges of using the broadband spectroscopy to measure gas temperatures quantification of the absorption of the core gas infrared emission due to the cold boundary layer on the optical access of combustion systems . To evaluate and validate the new methodology it was applied to measure the gas temperature and boundary layer thickness of a mixture of methane carbon dioxide and nitrogen using Rapid Compression Machine RCM . High speed infrared cameras with two filters at wavelength ranges of 3.329 to 3.629m and 4.069 to 4.445m were used to measure the filtered natural emission of methane and carbon dioxide during the post compression period . Measured gas temperatures at two conditions were compared with the modeled temperature calculated using the isentropic compression equation . Excellent agreement within 1 was reached between modeled and measured gas temperatures .
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A new mathematical methodology to simultaneously measure the gas temperature and boundary layer thickness was developed and used at high gas pressure and temperature. The new methodology is based on the line of sight broadband natural infrared species emission. The new methodology solved one of the main barrier on using the broad band spectroscopic the effect of the cold boundary layer on optical access of practical combustion systems.
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S0022407319304741
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Comparing to the 1 D resonators like strips the 2 D resonators such as squares can excite the higher order 2 D magnetic plasmon modes in addition to the fundamental and higher order 1 D MP modes . However the low absorptivity of 2 D MP modes greatly limits its applications . We propose and demonstrate an idea utilizing the near field coupling of electromagnetic fields accumulated around the tips of 2 D square resonators to enhance the electromagnetic fields intensity and the emissivity or absorptivity of 2 D MP modes . The tip tip coupling structure is formed by rotating the square resonators array 45 . The experiment demonstrates the 4.5 times absorptivity enhancement of higher order 2 D MP mode from 12.5 to 55.8 in addition to the fundamental MP
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Near field coupled lighting rod effect is proposed and demonstrated. Rotating square resonators array 45 to form tip tip coupling structure. Demonstrates 4.5 times emissivity enhancement of 2 D 1 2 MP mode. Near field coupled lighting rod effect is strongly dependent on coupling distance.
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S0022407319304777
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Nondestructive inline measurements of submicron sized particles and gas bubbles are required in many fields of study including environmental industrial and biomedical research . The single particle extinction and scattering method is a promising technique for this purpose because of its sensitivity to both the complex refractive index and the size of individual particles . Herein an original modification of the SPES instrument that suppresses measurement bias and background noise is presented . In addition relevant theory and a practical algorithm for data analysis are presented . The inverse scattering problem of estimating the physical characteristics of a particle from SPES data using Bayesian theory for model selection is formulated and the performance of the algorithm using simulated data for spherical and non spherical particles is evaluated . The results suggest that a cluster of SPES data points for an ensemble of particles contains sufficient information to retrieve the complex refractive index and volume equivalent size distribution of the particles regardless of particle shape . The Bayesian inversion method also allows incorporation of informative data from other analytical methods through the model and parameter priors . As practical examples the SPES method was used to constrain the complex refractive index and size distribution of water insoluble aerosols contained in rainwater . The results suggest that the SPES method itself or its use in combination with other conventional analytical methods can quantify the complex refractive index and size distribution of almost any type of submicron particle in environmental industrial and biomedical samples .
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A non invasive optical particle characterization method for submicron particles. Accurate measurement of real and imaginary parts of complex refractive index. Accurate measurement of volume equivalent particle size distribution. Applicable to both spherical and non spherical particles. A novel Bayesian computational approach for solving inverse scattering problem.
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S0022407319304819
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This study develops a Weighting Featured Monochromatic Radiance method to efficiently and accurately compute the vector radiance including multiple scattering at the near infrared band . The monochromatic radiances within a spectral band that are of a high correlation are grouped to represent the average band radiance . The simulated radiance from WFMR is validated against a large variety of OCO 2 profiles . It is shown that the dominant errors introduced by the WFMR method are below 0.1 0.025 and 0.12 for O
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Proposed a method for efficient and accurate calculations of vector multiple scattering in near infrared band. Accuracy of 0.1 is achieved with computation speed improved by 12 order. Capture the realistic characteristics of atmospheric radiation from measurements of near infrared band.
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S002240731930487X
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This study presents the averaged lidar relevant radiative properties of numerically generated soot fractal aggregate ensembles . The radiative properties of these aggregates have been computed using the Superposition T Matrix Method with emphasis put on those that are most relevant to lidar application the backscattering and extinction cross sections the Lidar Ratio and the Linear Depolarization Ratio . These lidar relevant radiative properties have been computed over a broad spectrum going from the ultraviolet to the near infrared in order to address lidar instrument need for
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Lidar relevant parameters backscattering extinction lidar ratio and depolarization ratio are computed using MSTM for statistically representative ensembles of soot fractal aggregates. The monomer radius strongly influences all of the studied lidar relevant radiative properties. The number of monomers per aggregate has also a strong effect on the lidar cross sections but has a limited impact on the lidar parameters such as the Lidar Ratio and the linear depolarization ratio. The aggregate fractal dimension has a weak impact on all lidar relevant radiative properties.
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S0022407319305102
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In this study the principle advantages and disadvantages of the three representative chlorophyll fluorescence remote sensing inversion algorithms standard Fraunhofer Line Discrimination 3FLD and improved FLD were compared and analyzed and the inverted Gaussian model fluorescence inversion algorithm was proposed . Vegetation canopy spectral data were simulated by the soil canopy observation photochemistry and energy flux model . The analysis of the simulated and measured spectral data revealed that in contrast to the model parameters of sFLD 3FLD and iFLD those of IGM FLD have definite physical meanings . In addition the apparent reflectance baseline of IGM FLD was more reasonable than that of the other models . Given these properties the fluorescence inversion accuracy of the IGM FLD model was higher than that of the other three models . Moreover it only required the construction of a reflectance baseline in the 680800nm spectral range and can simultaneously invert the fluorescence information of the O
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An inverted Gaussian model IGM based vegetation fluorescence remote sensing inversion algorithm IGM FLD was proposed on the basis of the comparison and analysis of the FLD algorithms. The proposed algorithm uses the inverted Gaussian reflectance model to construct the apparent reflectance baseline of the red edge region of vegetation 680800nm spectral range and can simultaneously invert fluorescence intensity at the O2 B and O2 A bands. The IGM FLD algorithm shows definite physical meanings because the model has been found to provide an effective quantitative representation of the shape and position of the vegetation red edge reflectance in terms of parameters of physical significance in the manuscript.
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S0022407319305217
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A continuous wave quantum cascade laser based spectroscopic sensor is demonstrated to investigate the high resolution spectra of 35 spectral lines of NO
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CO. broadening coefficients in the 6.2m region have been measured. The continuous wavelet transform is used to determine the number and position of individual peaks. A continuous wave CW mid infrared quantum cascade laser QCL based spectroscopic sensor is demonstrated.
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S0022407319305266
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Directional radiative intensity over specific spectral region provides fruitful information inside gas fired systems and is very useful for inverse analysis such as temperature and species concentration reconstruction . The statistical narrow band model has acceptable time efficiency for practical applications and has been shown to have good accuracy to calculate integral radiative quantities such as radiative heat flux and radiative source term . No previous work provides its accuracy information for solving spectral radiative intensity in combustion systems which is to be investigated in this work . The SNB model is applied to solve radiative transfer in one dimensional gaseous media with black boundaries . Gaseous media of CO
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Spectral radiative intensity in gases by statistical narrow band model is investigated. Accuracy of spectral radiative intensity for CO. is good for H. O is not. A strategy to improve the accuracy of spectral radiative intensity is proposed.
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S0022407319305308
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Raman spectroscopy can be used to determine the vibrational frequencies of materials and from these the chemical compositions . Raman microspectroscopy can help in understanding the chemistry of atmospheric and other aerosols . This paper describes the use of an automated Aerosol Raman Spectrometer from Battelle to collect approximately 100 000 RS in 15 min intervals over 22.5h in Maryland USA . Approximately 9000 of these RS have intensities exceeding the thresholds used in this analysis . This paper describes and illustrates processing techniques used for the RS including detection and removal of RS exhibiting charring and estimation and removal of fluorescence and other broad features . RS exhibiting the D and G bands of soots and other black carbons are especially common in the data probably because the particles are charged to increase the collection efficiency of small particles the Raman cross sections of DGC are large and the sampling location is near major roads . RS consistent with calcium oxalate hydrates C
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Raman spectra RS of atmospheric aerosol particles were measured with a semi continuous system. Of the 100 320 RS measured in 22.5h approximately 9000 had intensities above the thresholds. RS were consistent with soots carbonates silicates sulfates iron oxides and biomaterials. RS consistent with calcium oxalate hydrates C. Ca 1. H. O where 0. 1 were seen. Particles were charred infrequently by the laser more often during daytime.
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S002240731930531X
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This article investigates the effects of increasing pressure up to 4 atm on radiative heat transfer in momentum driven methane turbulent jet flames by using well established chemical mechanism combustion soot production and radiation models . A transported PDF method is used to close properly the soot production turbulence interaction and the emission Turbulence Radiation Interaction . A Narrow Band CK model is used as the gas radiative property model . The absorption TRI is neglected based on the Optically Thin Fluctuation Approximation . In accordance with a previous study dealing with non sooting hydrogen flames 172179 the 3 atm and 4 atm flames are designed from the atmospheric flame by using a Froude modeling approach that allows to preserve the flame flow structure as the pressure is increased and hence to isolate the pressure effects on soot production radiative heat transfer and TRI . The effects of increasing pressure on radiant fraction result from two competing mechanisms i an increase in soot emission that tends to increase the radiant fraction and ii a reduction in flame transparency that tends to reduce it . For the present flames the first mechanism dominates the second resulting in an increased radiant fraction with increasing the pressure . The TRI effects on flame radiative loss are also governed by competing mechanisms . The enhancement mechanism is due to gas emission TRI and temperature self correlation effects on soot emission whereas the reduction mechanism is caused by the negative correlation between soot volume fraction and temperature . The former dominates whereas the latter becomes increasingly important with increasing the pressure . This limits the increase in the global radiative loss due to TRI as the pressure is increased . In addition numerical simulations show that the TRI effects can reduce the local radiative loss in regions of high soot concentration of the 4 atm flame .
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Numerical investigation of pressure effects on RHT and TRI in sooting flames. Specific high pressure flames have been designed based on Froude modelling. Two competitive mechanisms affecting the radiant fraction are evidenced. Two competitive mechanisms affecting TRI are evidenced.
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S0022407319305485
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In the optical measurement of submicron particle properties extra scattering generated by excess surface charges is no longer negligible as that in micron particles . When the surface charge density exceeds a certain threshold the scattering behavior of the particles will be jointly dominated by the particles themselves and the surface charges . In this paper the complex refractive index model is extended to be appropriate for both electrically neutral particles and electrically charged particles and the mechanism is explained how surface charges affects elastic scattering . Taking the Mie theory of charged submicron spherical droplets of water with salt as an example the influence of the surface charges on the complex refractive index and the scattering properties is discussed . Further a threshold of the surface charge density is confirmed above which extra scattering can not be ignored . By calculating a angular distribution of the scattered light intensity it is found that electrically charges have a magnifying effect on forward and backscattering of the particles
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Extend the complex refractive index model to the case of charged particles. Excess surface charges affect visible light scattering of submicron spheres. Surface charge amplifies the forward and backscattering of small particles. Lower limit of optical measurement can be extended by using the amplification effect.
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S0022407319305539
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Combining magnetic nanoparticles with noble metallic nanoparticles to construct multifunctional alloy nanostructures has become a powerful tool for imaging sensing medicine biology and cancer treatment and photothermal therapy . This work reports a study regarding the plasmonic properties of Co Ag and Co Au bimetallic alloys nanostructures on the electromagnetic spectrum . In this paper the optical properties of magnetic and plasmonic nanoparticles with different shapes sizes compositions and surrounding medium are investigated by using the discrete dipole approximation technique . The absorption and scattering localized surface plasmon resonance peak positions are found between 211964nm wavelengths ranges and can be tuned in the deep UV NIR region of the EM spectrum in accordance with the desired application . Further we calculate the refractive index sensitivity and figure of merit of LSPR based nanosensors . Although LSPR based sensors undergo low FOM as compared to conventional surface plasmon resonance sensors due to high losses from the radiative damping of localized surface plasmons waves . However LSPR based sensors have potential applications in gas and bio sensors technology viz . medical and environmental monitoring applications . In this work the main feature of LSPR peak is dependent on nanoparticle shapes sizes compositions and ambient medium and have ordered as prolate sphere cube rectangular shape NPs . These results suggest that the nanostructures of Co Ag and Co Au alloys associated with LSPR tunability and sensitivity can be used in biomedical and sensing environment technology such as detection of chemical and catalytic events .
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The present research is to highlight the studies of bimetallic alloys nanoparticles of magneto plasmonic nanostructures. The influence of size shapes compositions and surrounding medium for Co Ag and Co Au alloy nanoparticles results in significant change in optical properties. The spectra are found between 211 and 964nm wavelengths ranges and can be tuned in the deep UV NIR region of the electromagnetic EM spectrum. Tunability in sizes and shapes opens new potential use with desired applications in biomedical fields.
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S0022407319305540
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Light pollution poses a growing threat to optical astronomy in addition to its detrimental impacts on the natural environment the intangible heritage of humankind related to the contemplation of the starry sky and potentially on human health . The computation of maps showing the spatial distribution of several light pollution related functions is a key tool for light pollution monitoring and control providing the scientific rationale for the adoption of informed decisions on public lighting and astronomical site preservation . The calculation of such maps from satellite radiance data for wide regions of the planet with sub kilometric spatial resolution often implies a huge amount of basic pixel operations requiring in many cases extremely large computation times . In this paper we show that using adequate geographical projections a wide set of light pollution map calculations can be reframed in terms of two dimensional convolutions that can be easily evaluated using conventional fast Fourier transform algorithms with typical computation times smaller than 10
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A wide class of night sky brightness maps can be efficiently and accurately computed by means of fast fourier transforms FFT . A necessary condition is that the light pollution point spread function be shift invariant. The calculation of the 2D map then becomes a convolution. The time complexity of the direct calculation of the convolution of two 2D functions of size N. and N. is of order O N. . The FFT time complexity is of order O N. N. N. N. . For a 1000km1000km source region and a 300km300km PSF both with 0.5km pixel resolution the FFT calculation time is reduced by 10. in comparison with performing the direct convolution. Calculation times of order 10. s per output pixel can be easily achieved.
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S0022407319305552
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This study investigates the relationship between surface roughness and spectral reflectivity of DP980 an advanced high strength steel alloy . Five surface states were considered as received polished roughened and two coupons annealed in a reducing atmosphere . Radiative properties were measured using a UVVis NIR spectrophotometer and two FTIR spectrometers for directional hemispherical and specular reflectance measurements while surface roughness is determined using an optical profilometer . These measurements were interpreted in the context of a theoretical relationship derived from Davies model for specular reflectance . The reflectance of the polished coupon most closely matches this theory and the remaining coupons become more aligned with this relationship after large scale roughness has been removed from the profilograms using a wavelet filter . The results show that directional hemispherical reflectance can be predicted using Davies model with local scale roughness as opposed to macroscopic artifacts although this model is intended to capture the variation of specular reflectance with respect to wavelength .
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Annealed samples have distinct radiation property behavior from those of un annealed samples. For rough surfaces profilometer derived roughnesses are much larger than optically inferred values while the roughness of wavelet filtered profilograms are more consistent with the optically derived values. Radiative properties of Dual Phase steels can be estimated through specular model with local sub micrometer roughness scale which can be obtained by applying high pass wavelet filtering on the global surface texture. It is critical to account for the spectral dependence of smooth surface reflectance in Davies model using the Hagen Rubens relation.
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S0022407319305606
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A radiative transfer model that accurately and explicitly accounts for both absorbing and scattering effects requires a substantial amount of computational effort . In the longwave spectral regime the atmosphere is optically opaque and absorbs a large portion of terrestrial thermal radiation . To alleviate the computational burden clouds are assumed to be only absorptive in most general circulation models and their scattering effects are neglected . Using parameterizations of cloud bulk single scattering properties derived from the latest cloud optical property models for satellite remote sensing this study analyzes the numerical accuracy and efficiency of a variety of LW RTMs . The approaches considered in this study include the absorption approximation the absorption approximation with scattering parameterization the two stream approximation a hybrid two and four stream approximation and the discrete ordinate radiative transfer with multiple streams . These approximations are benchmarked against 128 stream DISORT calculation . After evaluating the full ranges of ice and water cloud optical and microphysical properties using these RTMs we find that neglecting LW scattering effect causes simulation errors as large as 15 by using the AA method . Among these RTMs the 2 4S method provides an optimal balance between computational efficiency and accuracy leading to the maximum cloud emissivity errors within 5 25th to 75th percentile errors about 1 and almost zero net bias . Therefore the 2 4S approximation is computationally accurate and yet affordable option for incorporating cloud longwave scattering effect into the radiation schemes used in weather and climate models .
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MC6 ice and water cloud and THM ice cloud LW optical properties are parameterized. 2 4 stream combination is approximately as accurate as 4 stream DISORT. 2 4 stream combination facilitates accurate and efficient flux simulations.
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S0022407319305679
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The absorption cross sections as important spectroscopic data can be used for the identification and quantitative measurement of components . However in view that carbon monosulfide is unstable and highly reactive it is difficult to measure the absorption cross sections of CS . Therefore a method for measuring absorption cross sections of CS based on the dynamic equilibrium between carbon disulfide CS
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A method for measuring absorption cross sections of unstable CS is proposed. The experimental device for measuring the CS concentration is designed. Different concentrations of CS are obtained by the photolysis of CS. The absorption cross sections of CS are provided for the first time.
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S0022407319305709
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An automated Aerosol Raman Spectrometer was used to measure approximately 100 000 Raman spectra during a 24 hour sampling period . The approximately 9000 RS that exceeded thresholds for Raman or fluorescence intensity were studied . Unstructured cluster analysis of the initial RS and the RS remaining after approximated fluorescence was removed resulted in clusters which had Raman peaks consistent with quartz calcite dolomite gypsum anhydrite iron oxides biological materials and calcium oxalates and materials that exhibit D and G bands . A set of RS which are dominated by a broad fluorescence and include only not detectable or very small Raman peaks were assigned to a fluorescent materials category with approximately 900 spectra . The temporal changes in the numbers of RS consistent with different materials are illustrated . The highest numbers of RS consistent with oxalates appear during the nighttime . The numbers of RS consistent with some type of soot increased during the day . This increase occurred after PM
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Over 9000 Raman spectra RS of atmospheric aerosol 22.5hrs data were clustered. RS were consistent with black carbon biological particles oxalates and minerals. RS were consistent with quartz orthoclase iron oxides calcite dolomite gypsum. Time series plots show RS consistent with oxalates occurred mostly before 2 PM. Fluorescence spectra in RS were approximated removed from the RS and clustered.
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S0022407319305734
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In atmospheric radiative transfer models the light scattering properties of the nonspherical particles are needed to be averaged over specific orientation and size distributions to obtain the representative values . However since the light scattering simulation processes of the typical models are closely dependent on particle s orientation their computations should be repeated for many times to realize the orientation averaging process which is a very time consuming task . To solve this problem the analytical algorithm to calculate the scattering parameters of the random oriented particles based the Invariant Imbedding T matrix method is developed by Bi L. by which the scattering parameters of the randomly oriented particles can be calculated analytically . To give a more full description of this algorithm the derivation process of this model is deduced following Mishchenko s idea in this paper . To facilitate the realization of this algorithm an efficient implementation of the computational scheme is also introduced in detail . To validate the modeling accuracy of this algorithm the results of the IIM T matrix method are compared with those of the EBCM T matrix method and DDASCAT for particles with different sizes and shapes . The results show that good agreement is achieved between the scattering parameters calculated by different models where the relative differences between the phase functions calculated by IIM and EBCM method are generally smaller than 5 and the relative deviations of the extinction scattering cross sections are all less than 0.5 which indicates that the analytical algorithm can simulate the scattering parameters of the random oriented particles with high accuracy . Compared to the traditional T matrix method the advantage of this algorithm is that it can be applicable to arbitrarily shaped particles .
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To give a more full description of the analytical algorithm to calculate the scattering parameters of the random oriented particles with arbitrary shapes the derivation process of this model is deduced following Mishchenko s idea in this paper. To facilitate the realization of this algorithm an efficient implementation of the computational scheme is introduced in detail. The analytical algorithm can calculate the scattering parameters of the random oriented particles with high accuracy and efficiency.
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S002240731930576X
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Two models for millimeter wave absorption by molecular oxygen in the air are updated . To derive the updated parameter set earlier resonator spectrometer data are refined and recent data on the collisional parameters temperature behavior are taken into account . The updated models provide significantly better agreement between laboratory measurements and calculated absorption band profiles than their earlier versions . The predictive ability of the models is confirmed by new experimental data . The covariance matrix of empirical parameter uncertainties together with absorption calculation uncertainty are evaluated for both updated models . Contributions of the various sources to the total calculation uncertainty are discussed .
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Resonator spectrometer data are re treated with respect to minor systematic errors. Models using two different approaches are revised. Improvement of 60 GHz molecular oxygen band profile modeling is demonstrated. Model parameters set is provided for practical use. Uncertainty and its sources are analyzed.
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S0022407319305783
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Measuring the size distribution of dust particles is of interest in many scientific and technological contexts . One of the most widely used techniques is laser light scattering which provides the distribution of surface equivalent spheres that fits the observed angular dependence of light scattered by a sample . We have revisited the problem of the uncertain lower size limit of this method by simulating laboratory measurements of the light intensity scattered by polydisperse spheres and irregular particles from which the original distributions are retrieved by regularized inversion with Mie and Fraunhofer phase functions . For the usual combination of blue
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A computational study of the inversion of the average phase function of particle clouds sheds light into the uncertain lower size limit of the widely used laser light scattering LLS particle sizing method. For spheres retrieved size ditributions are sensitive to uncertainty in the complex refractive index due primarily to the dependence of the scattering efficiency curve on this parameter for. 3 m. The scattering efficiencies of irregular and porous model particles are lower and smoother than for spheres and these differences are imposed on the retrieved size distributions. If the real part of the refractive index. is uncertain it is safer to assume a value of. at the higher end of the uncertainty range. LLS size distributions of irregular and porous particles may be inaccurate for. 1
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S0022407319305850
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Five radiative transfer schemes are compared in infrared spectra using the Rapid Radiative Transfer Model for General Circulation Models Applications . By calculating the root mean squared error of net flux in various atmosphere the general accuracy of these schemes ranked from low to high are non scattering simplification the adding method of
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Five radiative transfer schemes are compared in infrared spectra using RRTMG. Two methods for handling the overlap of solar and infrared spectra are studied. All schemes are implemented with single column experiment and large sample test. A new scheme is established to solve the solar energy in longwave spectra.
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S0022407319305874
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The impact of radiative transfer scheme on global climate model simulation is presented in this paper by comparing the difference between two stream adding method and adding algorithm of the four stream discrete ordinates method radiation schemes in the Atmospheric General Circulation Model of the Beijing Climate Center . Only consider the effects of the calculation method itself the 4DDA reduces the negative shortwave cloud radiative effect in the areas with a significant fraction of low cloud while enhances the negative shortwave CRE in the areas with the large fraction of high cloud . For the longwave CRE the 4DDA enhances the longwave CRE drastically in the regions with a significant fraction of the high cloud . The feedback of clouds results in more interesting results . The 4DDA produces more accurate shortwave CRE in the region over the land and ocean in the middle and high latitude areas . The longwave CRE simulated by 4DDA is better than that affected by 2DDA over the ground in Africa South America and Atlantic . The change of radiation scheme affects the simulation of other meteorological variables . The simulation of global humidity by 4DDA is improved obviously . The 4DDA simulates more accurate temperature in continents of the northern hemisphere and precipitation in North America Africa northern Indian Ocean and western Pacific . Although the improvement of every physical process is required to develop the models implementing 4DDA scheme into GCM and evaluating the effect of it are necessary and meaningful .
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The 4DDA reduces the negative shortwave CRE in the areas with the significant fraction of low cloud while enhances the negative shortwave CRE in the areas with the large fraction of high cloud. For the longwave CRE the 4DDA enhances the longwave CRE drastically in the regions with a significant fraction of high cloud. The 4DDA enhances the negative shortwave CRE in the areas dominated with high cloud. The 4DDA enhances the longwave CRE drastically in the regions with a significant fraction of high cloud.
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S0022407319305916
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The Atmospheric Chemistry Experiment is a satellite based mission that has been probing the Earth s atmosphere via solar occultation since February 2004 . Instruments on board include a high resolution Fourier transform spectrometer and a pair of filtered imagers . A new processing version has been implemented for these instruments . Analysis for the ACE FTS instrument makes use of the latest spectroscopic information and features improved accuracy in forward model calculations including a new instrumental line shape and employing a 100m altitude sub grid within the tangent layer of the 1km altitude grid employed in previous processing versions . Changes were made in the handling of solar and deep space calibration spectra to avoid systematic errors that impacted previous processing versions . Emphasis was placed on improving software robustness as well as minimizing occurrences of unphysical oscillation in retrieved profiles . Seven new molecules and three new isotopologues were added to the list of atmospheric constituents retrieved from the previous processing version for a total of 44 molecules and 24 isotopologues . For the imagers forward model calculations were changed to a 100m altitude grid in version 4 processing .
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New processing version for the ACE FTS instrument. Retrievals for ten new atmospheric constituents. Improved accuracy in forward model calculations. Reduced unphysical oscillations in retrieved profiles.
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S0022407319305990
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Far to mid infrared spectral radiances measured either from high altitude platforms or from ground can be processed to retrieve atmospheric vertical profiles and cloud parameters variables particularly relevant in climate change studies . The retrieval requires a forward model with the capability of simulating the multiple scattering from cloud particles . The Discrete Ordinate Radiative Transfer offers this possibility however accurate simulations can be obtained only with a huge computational load . We developed a forward retrieval model based on the two streams
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Introduction of a two stream. Eddington approximation algorithm to simulate the Far InfraRed Earth spectrum. Study of SACR accuracy by means of the comparison with LBLDIS LBLRTM DISORT code. Performance of the simultaneous retrieval of atmospheric and cloud parameters by using SACR algorithm.
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S0022407319306132
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Flow cytometry and inherent optical property measurements of UK coastal waters were used to evaluate optical closure of different combinations of models for particle size refractive index and shape . The particle size and refractive index distributions were derived from flow cytometry measurements and subsequently simplified through averaging down to the simplest model consisting of a Junge size distribution with a single bulk refractive index . Models for particle shapes included homogeneous spheres coated spheres and hexahedra . The simplest particle model based on a Junge size distribution and a single bulk refractive index gave the poorest quality of closure suggesting that it underestimates particle complexity in the sampled waters . Other particle models using more detailed combinations of size and refractive index distributions gave broadly equivalent results for absorption and scattering . Backscattering was better represented by the most complex particle size and refractive index model indicating that backscattering is sensitive to those factors . The homogeneous spherical model gave relatively good results which is expected because the inversion of size and refractive index distributions from flow cytometry is based on the homogeneous spherical model using forward and side scattering signals . Lorenz Mie theory assuming homogeneous spheres provided optical closure that was generally as accurate as models with more complex particle shape and structure . Cumulative contribution simulations revealed that particles between 0.5 and 20m substantially contributed to attenuation scattering and backscattering while particles larger than 20m mainly contributed to absorption and small particles contribute to 3040 of backscattering .
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Detailed particle characteristics were studied for optical closure. Use of a single slope and one refractive index underestimates particle complexity. Lorenz Mie and more complex particle shape and structure models performed broadly. Backscattering is sensitive to detailed size and refractive index distribution. Particles between 0.520m contribute significantly to the IOPs.
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S0022407319306156
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This paper evaluates uncertainties in the ocean permittivity model needed to compute surface emission and reflection at frequencies of 6 90GHz . The study transforms permittivities and laboratory measurement uncertainties into typical brightness temperatures for microwave imagers . It is established that the permittivity model used by FASTEM agrees with the laboratory measurements to within their published uncertainties at frequencies of 23GHz 37GHz and 89GHz but this is not the case at 6.8 10.65 and 18.7GHz particularly at low temperatures .
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Estimated uncertainties in the FASTEM permittivity model are 0.5 2K at 6 90GHz. FASTEM agrees with permittivity measurements within uncertainties at 23 90GHz. Differences between FASTEM and permittivity measurements are observed at 6 19GHz. A better fit to 6 19GHz measurements leads to increased bias in satellite O B.
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S0022407319306259
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As typical structured light beams Laguerre Gaussian beams Bessel beams and Airy beams have attracted great attention for their fascinating features and wide potential applications . Explicit expressions for the electromagnetic field components of these beams obtained from a vector angular spectrum analysis are of particular importance to study a variety of problems involving the propagation transmission and reflection of laser beam as well as light matter interactions . In the present work we first briefly recall the scalar expressions of typical structured light beams including the LaguerreGaussian beams Bessel beams and Airy beams . Then we present the formulae of vector angular spectrum representation under different conditions . Finally we derive in detail the analytical expressions for the electromagnetic field components of these structured light beams and provide some important integral formulae . Additionally distributions of the electromagnetic fields as well as the phase Poynting vector and energy density are displayed and analyzed for these typical structured light beams .
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A vector angular spectrum analysis of typical structured light beams is reported. The formulae of vector angular spectrum representation under different conditions are provided. Explicit analytical expressions for the field components of Laguerre Gaussian beam Bessel beam and Airy beam are derived. Distributions of the field components phase Poynting vector and energy density are explored for typical structured light beams.
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S0022407319306417
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The use of high aspect ratio cylindrical pressure vessels and rotationally periodic burners in Pressurized Oxy Coal furnaces leads to physical behavior that is 3D periodic near the burner but which transitions to axisymmetric towards the outlet . A fully 3D model would consume unneeded resources and an axisymmetric model would fail to capture periodic features of the near burner region such as recirculation zones . The present work evaluates the ability of a dimensionally adaptive mesh to improve computational speed while still accurately calculating heat flux for such cylindrical systems . The Discrete Ordinates Method was used to solve the cylindrical Radiative Transfer Equation on both a dimensionally adaptive mesh and a fully 3D mesh . The effects of both spatial and angular refinement on speedup and agreement between the adaptive and fully 3D mesh were studied . For the four cylindrical combustor configurations studied speedups ranged from 46.6 on a coarse adaptive mesh to 49.1 on a fine mesh . Increasing angular resolution decreased speedups from 48.0 at S
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Discrete Transfer radiation calculations were performed on a hybrid 3D 2D 1D mesh. Limited testing of robustness of the technique. Effects of spatial and angular refinement investigated. Speed increases in excess of 49 were observed with less than 1 error.
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S0022407319306429
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In this semi tutorial paper we revisit the interference phenomena caused by pairs of co propagating or counter propagating transverse electromagnetic waves by letting the host medium be absorbing . We first consider plane waves in an unbounded medium summarize the standing wave solution of the Maxwell equations and discuss specific effects caused by nonvanishing absorption . We then consider the superposition of plane and spherical waves in the context of far field electromagnetic scattering by a particle . To this end we modify the classical Jones lemma by allowing nonzero absorption in the host medium and consider its most obvious consequences such as forward and backscattering interference . The physical similarity of the two scenarios is discussed .
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We revisit interference phenomena caused by pairs of co propagating or counter propagating transverse electromagnetic waves by letting the host medium be absorbing. We first consider plane waves in an unbounded medium. We then consider the superposition of plane and spherical waves in the context of far field electromagnetic scattering by a particle. The physical similarity of the two scenarios is discussed.
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S0022407319306430
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We study the effect of anisotropy on the extinction absorption and scattering spectra of optically uniaxial spherical particles which are small compared to the wavelength of the incident light in the infrared spectral region . To do so we compare simulated Finite Difference Time Domain spectra of the uniaxial sphere to spectra of a corresponding isotropic materials calculated with Mie theory which are given the principal dielectric functions of the ordinary and extraordinary axes respectively . Several effects of anisotropy can be observed caused by the incident plane wave being bent around the sphere and penetrating into the sphere .
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Effect of material anisotropy on cross section spectra of small particles is investigated. FDTD spectra of anisotropic materials are compared to Mie spectra. Absorption scattering extinction is influenced in different ways. Effect of anisotropy strongly dependent on geometry. No range of validity can be given for 1 32 3 approximation.
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S0022407319306478
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This paper investigates conditions necessary to match the irradiance derived by integrating radiances measured by a narrow field of view scanning radiometer with the irradiance measured by a hemispherical radiometer both placed at a satellite altitude for Earth radiation budget estimates . When all sources are similar and they are spatially distributed randomly then integrating radiance for the irradiance does not introduce a bias . Although the exact magnitude of the bias in other conditions is unknown a finite area of the aperture that is much larger than the coherence area of radiation contributing to the Earth radiation budget and a finite time to take a single measurement that is longer than the coherence time are likely to make the difference of the irradiance integrated from radiances and the irradiance measured by a hemispherical instrument insignificant . This conclusion does not contradict the existence of spatial coherence of light from incoherent sources . Therefore electromagnetic energy absorbed by Earth is derivable from radiances measured by a scanning radiometer integrated over the Earth viewing hemisphere and then averaging across all locations on the satellite orbital sphere when combined with solar irradiance measurements . Comparisons made in earlier studies show that the difference is less than 1 . In addition when surface irradiances computed by a radiative transfer model constrained by top of atmosphere irradiances derived from radiance measurements are compared with downward shortwave irradiances taken by combinations of a pyreheliometer and a shaded pyranometer or pyranometers and with longwave irradiances taken by pyrgeometers the biases in monthly mean irradiances are less than the uncertainties in the surface observations .
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Rigorous descriptions of a narrow field of view scanning radiometer measurements using the Poynting vector are provided. Electromagnetic energy absorbed by Earth is derivable from radiances measured by a scanning radiometer. The conclusion is consistent with the existence of spatial coherence of light originated from incoherent sources.
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S002240731930648X
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The simulation of astronomical spectra of cool stars brown dwarfs and exoplanets requires high resolution line lists and absorption cross sections of many molecules . Similar data sets are needed for the Earths atmosphere and other planets in our solar system . The requirements for line lists are reviewed and methods used to create them are discussed . Equations to convert between different units are provided . The MoLLIST data compilation is presented and used as an example .
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Review of requirements and calculations for line lists for astronomical and atmospheric applications. MOLLIST Molecular Line Lists Intensities and Spectra data compilation is presented. Units used in line lists and their conversion are discussed.
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S0022407319306491
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In the present study the structure of the secondary rainbow is examined for the case of a spherical drop illuminated by a Gaussian beam with its waist radius comparable to the drop radius . Computations are performed using the generalized Lorenz Mie theory and Debye series . The influence of beam waist radius on the secondary rainbow pattern is investigated . The possibility of extracting size and refractive index from the secondary rainbow pattern is then evaluated by examining the achievable accuracy . The influence of incident position of the beam on extracting drop information is also investigated . For a Gaussian beam centered on the impact parameter associated with the Descartes ray the absolute error of the refractive index is smaller than 6.810
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By using generalized Lorenz Mie theory and Debye series decomposition the influence of a Gaussian beam on the scattering pattern of drops in the secondary rainbow region is studied. The secondary rainbow pattern is used to estimate the achievable accuracy when extracting refractive index and size of drops. The influence of incidence position of the Gaussian beam on the drop characterization is investigated.
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S0022407319306533
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This work is an expanded study of one previously published on retrievals of aerosol microphysical properties from space borne multiwavelength lidar measurements . The earlier studies and this one were done in the framework of the NASA Aerosol Clouds Ecosystems NASA mission . The focus here is on the capabilities of a simulated spaceborne multiwavelength lidar system for retrieving aerosol complex refractive index m m
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Space borne simulated lidar systems. Space borne retrievals of vertical profiles of aerosol single scattering albedo. Error sensitivity of space lidar systems.
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S0022407319306545
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The energy levels and electric dipole matrix elements of Rb atom are calculated using the relativistic configuration interaction with core polarization method . These energy levels and matrix elements are further employed to calculate the electric dipole static and dynamic polarizabilities of the 5
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Static and dynamic polarizabilities of the 5. 5. states are calculated. Magic wavelengths of the 5. transitions are given for linearly and circularly polarized light. We suggest that the accurate measurement on the magic wavelengths for circularly polarized light could be used to determine the high precise oscillator strengths of the 5. 6. 7. 8. 5. 6. 7. 8. transitions.
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S0022407319306557
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In order to design a viable nanoplasmonic device it is essential to be able to control the excitation of plasmon polaritons using an external voltage bias . To achieve this we can employ the phenomenon of electron inelastic tunneling followed by photon excitation and a subsequent launch of the plasmon polariton . Unfortunately this process suffers from low efficiency . In this paper we propose the use of spherical Si and Au nanoantennas to increase the energy conversion from photon to plasmon . We show that size governed Mie resonances of nanoantenna determine the spectral position of peak efficiency . The size of the nanoantenna also determines the efficiency value which can reach up to 25 . This is an order of magnitude higher compared to the case without nanoantenna . An analysis of thermal stability proves that both types of nanoantennas can operate under high current rates at room temperature .
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SPP launch is enhanced by a spherical metal au or all dielectric Si nanoantenna. Spectral position of peak efficiency is related to Mie resonances of nanoantennas. The enhancement originates from electric dipole and electric quadrupole modes. The peak value of the energy conversion efficiency reaches up to 25 .
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S0022407319306600
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A systematic diagnosis study was performed to understand the expansion dynamics and emission characteristics of nanosecondpicosecond collinear double pulse laser induced plasma of aluminum in air at atmospheric pressure by combining shadowgraphy interferometry and spectrometry . The expansions of the shock waves were investigated using shadowgraphic images and their distinctive evolution properties were analyzed including the colliding and merging of picosecond and nanosecond shock waves but more particularly the appearance of a third shock wave and the formation of an interaction layer . The plume expansion and electron density distribution of DP plasma were discussed by comparison with single pulse plasma based on the diagnosis results of interferometry and spectrometry . In addition evolution characteristics of emission spectra of different species in SP and DP cases were also analyzed and evident signal enhancements for atomic and ionic lines were obtained in collinear DP case .
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A systematic diagnosis study is performed to understand the expansion dynamics and emission characteristics of collinear double pulse DP laser induced Al plasma in air at atmospheric pressure by combining shadowgraphy interferometry and spectrometry. Some distinctive evolution properties of the shock waves are observed including the colliding and merging of picosecond and nanosecond shock waves but more particularly the appearance of a third shock wave and the formation of an interaction layer. The plume expansion and electron density distribution of collinear DP laser induced Al plasma are discussed by comparison with single pulse SP case based on the diagnosis results of interferometry and spectrometry. A signal enhancement for atomic and ionic lines is observed and analyzed in the collinear DP case.
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S0022407319306752
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Many body interaction has complex effect on near field radiative heat transfer in particulate systems which can not only enhance but also inhibit NFRHT . This work studies the NFRHT in a chain of particles with another chain in proximity at room temperature based on the many body radiative heat transfer theory . Both dielectric and metallic particles are considered . Significant many body effect is observed with the existence of a proximate chain in the near field which generally inhibits heat transfer in the main chain . Meanwhile the energy density distribution around the main chain is weakened . The proximate chain has weaker inhibition effect on NFRHT in the Ag main chain than that on NFRHT in the SiC main chain . The SiC proximate chain inhibits NFRHT in the SiC main chain more significantly than the Ag proximate chain which is attributed to strong coupling of localized surface phonon resonance between the particles in the two chains around the characteristic thermal wavelength . For Ag main chain however due to mismatch between the thermal frequency and the particle resonance frequency the proximate chain shows very weak effect on NFRHT in the main chain . The proximate chain with various translation distances in its longitudinal direction has negligible effect on NFRHT in the main chain . This work will help the understanding of the effect of many body interaction on NFRHT in particulate system .
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Observed significant many body effect with existence of proximate chain in near field. Proximate chain generally inhibits radiative heat transfer in the main chain. Translation of proximate chain has negligible effect on heat transfer in the main chain. Strong heat transfer inhibition is due to LSPR coupling near the thermal wavelength.
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S0022407319306776
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Knowing the optical properties of a sample is important in many scientific fields such as space science climate studies and medicine . In many of these applications the samples are fragile unique or available in limited quantities and have to be subsequently studied by additional techniques implying that sample preservation is important . Established light scattering single particle measurements involve attaching the sample to a holder or measuring a laminar flow of particles neither of which allows a controlled unperturbed non destructive measurement .
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We present the first non destructive 4 particle scatterometer of its kind. Controlled acoustic levitation allows measuring the sample from any angle. Polarimetric angular maps of light scattering from a mm sized sample are demonstrated. The non contact sample manipulation allows handling high value fragile samples.
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S0022407319306818
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The spherical wavelet based on the lifting scheme is introduced for adaptive discrete ordinate sampling of the radiation fields particularly in the radiative transfer computation using iterative schemes . The lifting scheme for wavelet transform is described from an implementation point of view including the construction of hierarchical geodesic grids on the sphere and wavelet constructions . In addition we compare the method with the conventional spherical harmonics numerically investigating the transformation error and efficiency . The transformation matrices are built in the least squares sense . The results demonstrate the feasibility of using spherical wavelets as an adaptive discrete ordinate sampling method at the cost of
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The spherical wavelets is introduced for adaptive discrete ordinate sampling in radiation fields representation. The transformation between spherical harmonics representation and spherical wavelets representation of the radiation fields is investigated. The number of adaptive discrete ordinates is approximately equal to the number of spherical harmonics coefficients.
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S0022407319306855
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Canopy reflectance simulation was widely developed using Monte Carlo ray tracing . Nevertheless the proposed models assume leaf as Bi Lambertian medium . Based on the recently developed leaf MC ray tracing code this study proposes to couple MC ray tracing simulations on leaf and canopy levels . Firstly at the first level the bidirectional scattering distribution function is computed for unpolarized incoming rays as well as some common states of polarization producing together a polarization decomposition basis allowing to derive the Stokes phase function . Moreover discretizing both incident and scattering angles over the sphere allows to produce a database of all possible Stokes phase functions . Secondly at the canopy level the reflectance is simulated using ray tracing technique when ray is intercepted the scattering is done considering the appropriate Stokes phase function in the leaf database . Simulation of multiple wavelengths is accelerated based on a new MC weighted sampling technique permitting to consider the same tracing for all the wavelengths together . Simulation results show the relevance of such modeling compared to traditional models . Indeed from one side the canopy bidirectional reflectance depends on the leaf BSDF thus if leaves are assumed Bi Lambertian surfaces leads to inaccurate results and from the other side the reflectance is sensitive to polarization and neglecting it affects the results mainly when the incident light is polarized . Comparison with actual polarized reflectance measurements presented in literature shows good agreement with same trends and variation ranges . Quantitative validation of our canopy level model is done using the ROMC web tool . Reflectance RMSE between our simulations and the ROMC reference is lower than 0.02 .
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Vector radiative transfer to model leaf canopy polarized reectance is proposed. Decomposing incident light into a basis of polarization allows to derive the Stokes phase function at leaf level. Discretizing wavelength domain incident and exiting angles allows to create a database of Stokes phase function. Monte Carlo weighted sampling allows to predict the ray tracing from one wavelength to another on leaf and canopy levels. Polarization and 3 D structure of leaves are not negligible.
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S0022407319306880
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This paper presents a novel mathematical framework to interpret the polarized lidar backscattering pattern for 1D water clouds . The framework is based on the multiple scattering of the lidar signals within small angle range . An approximation is made that both the outgoing and returning trajectories are assumed to be along nearly planar forward scattering sequences . For lidar axial symmetrical system a quasi linear mathematical relationship is built between the observed reduced Mueller matrix and the backscattering phase matrix and can be generalized to arbitrary scattering orders . For validation we extend the radiative transfer model MSCART to simulate linearly and circularly polarized lidar signals . Meanwhile we propose the azimuthal Fourier expansion to extract the reduced Mueller matrix results from the MSCART simulation . The numerical evaluation experiments demonstrate that our derived mathematical expressions could extend the polar angle dependence of the reduced Mueller matrix from second order to higher order multiple scatterings . The relation can serve as a useful tool in understanding lidar polarization observations and designing a CCD polarized lidar instrument .
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New multiple small angle scattering framework is presented to interpret lidar backscattering reduced Mueller matrix. Quasi linear relationship between reduced Mueller matrix and single large angle backscattering phase matrix is established and validated. Radiative transfer model MSCART is extended to simulating linearly and circularly polarized lidar Stokes vector signals. Azimuthal Fourier transform technique is proposed to extract reduced Mueller matrix from MSCART simulated results.
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S0022407319306958
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The radiometric properties of micro nano aggregates formed by nano monomers are essential in many scientific disciplines . The aggregate model of single sized monomers is often used to calculate the radiometric properties of micro nano aggregates . However the size distribution of monomers commonly exists in most of the actual aggregates and critically influences the radiometric properties . However the influencing mechanism remains unclear . This paper discusses the influence of size distribution of monomers on the radiometric properties of micro nano aggregates formed by nano monomers . The monomers of the aggregates have lognormal size distributions . Diffusion limited aggregation method is used to generate the structure of aggregate and multi sphere T matrix method is used to calculate the extinction efficiency absorption efficiency scattering efficiency and phase function of aggregate for three representative materials and different size distributions of monomers . The influence of the geometric standard deviation of lognormal distribution and monomer number on the radiometric properties of aggregate for the three representative materials is investigated and the mechanism is explained . Results show that the extinction and absorption efficiencies of gold aggregate decrease as the geometric standard deviation increases with the same average monomer size due to the coupling particleplasma mode oscillation alternating between super radiation and sub radiation . Meanwhile the extinction efficiency of ice and black carbon aggregates increases due to the increase in large monomers as the geometric standard deviation increases from 0 to 0.5 . The size distribution of monomers mainly affects the distribution of back scattering in comparison with forward scattering . For extinction and scattering efficiencies the aggregate model with size distribution of monomers and the aggregate model with single sized monomers are close for gold aggregate the former model is larger than the latter model for black carbon and ice aggregates . For absorption efficiency the former model is lower for gold aggregate and higher for black carbon aggregate .
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The influence of size distribution on aggregate radiometric properties is analyzed. The influence of monomer numbers on aggregate radiometric properties is analyzed. The mechanism of the monomer size distribution on aggregate radiometric properties is revealed. The deviation of the single sized model to the distribution sized model is calculated.
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S002240731930696X
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We address the actual problem of retrieving the physical parameters of ejecta from data of heterodyne Doppler velocimetry . Under the assumption that ejected particles are randomly spaced and their number within the probed volume is great the noise free component of the power spectrum of heterodyne beats is shown to be expressed in terms of a solution to the transport equation for the field correlation function which accounts for multiple scattering and absorption of the probing beam in the ejecta cloud . This provides a means for theoretical modeling of experimental Doppler data . The ejecta cloud is considered as a plane layer of particles moving in the air away from the free surface of the shock loaded sample . The spatial profile of the scattering coefficient and the cloud thickness are related directly to the distribution of ejected particles over velocities and coordinates . The slowing down of ejected particles in the air leads to an ambiguous relation between the velocity of particles and their position resulting in essential complication of the particle distribution . Using a multi group description of the ejecta cloud we reduce the transport equation to a system of linked Milne like equations . The system is solved numerically with the discrete ordinate code . Varying the values of the cloud optical thickness and the parameters of the particle distribution over sizes and initial velocities we fit the calculated spectrum to the time resolved data of heterodyne Doppler measurements . Such an approach enables retrieving the primary ejecta characteristics directly from heterodyne experiments . Application of the proposed method to the velocimetry data on ejecta is presented .
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The possibility of retrieving the density velocity and size distributions of ejecta from time resolved data of heterodyne Doppler measurements is demonstrated. The noise free component of the power spectrum is expressed in terms of a solution to the transport equation for the field correlation function. The transport equation is solved numerically for a multi group description of the cloud of ejected particles taking into account their slowing down in a gas medium. Application of the developed approach to the experimental velocimetry data is presented.
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S0022407319306983
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Radiative transfer calculations in complex three dimensional domains are plagued by computational bottlenecks due to the combined cost of resolving spectral angular and spatial dependence . The current work presents a systematic study into the efficacy of three commonly used reduced order wide band models Planck averaging and statistics based
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Radiative transfer calculations expensive due to combined cost of resolving spectral angular and spatial dependence. Wide band models such as Planck averaging k distribution and theory of homogenization allow reduced order representation of spectral variation. Conventional wide band models strictly derived for local thermodynamic equilibrium conditions which limits their accuracy when simulating non equilibrium radiation. New generalized grouping strategy developed for defining larger groups of individual frequencies to predict both total quantities of interest and their detailed frequency distributions.
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S0022407319307010
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Hyperspectral observations have become one of the most popular and powerful methods for atmospheric remote sensing and are widely used for temperature gas aerosol and cloud retrievals . However accurate forward radiative transfer simulations are computationally expensive since typical line by line approaches involve a large number of monochromatic radiative transfer calculations . This study explores the feasibility of machine learning techniques as an example for fast hyperspectral radiative transfer simulations by performing calculations at a small fraction of hyperspectral wavelengths and extending them across the entire spectral range . Results from the NN model are compared with those from a principal component analysis model which uses a similar principle of dimensionality reduction . We consider hyperspectral radiances from both actual satellite observations and accurate line by line simulations . The NN model can alleviate the computational burden by two to three orders of magnitude and generate radiances with small relative errors the performance of the NN model is better than that of the PCA model . The model can be further improved by optimizing the training procedure and parameters the representative wavelengths and the machine learning technique itself .
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A fast hyperspectral radiative transfer RT model based on neural network NN is developed. The NN model achieves similar accuracy to widely used principal component analysis models. The machine learning technique has great potential for developing fast RT models based on extending radiances calculated at a small number of wavelengths. The NN model can be easily coupled with line by line or fast RT models to improve computational efficiency.
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S0022407319307071
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The size and shape characterization of irregular particles is of great significance in the comprehensive understanding of many natural and industrial processes . The dual beam interferometric particle imaging technique is adapted from a dual beam backward illumination configuration of interferometric particle imaging to access the size and 2D shape of an irregular particle from its interferogram . An experimental setup combining the digital inline holography and DIPI techniques characterizes the same projection of the same particle with a color camera permitting the accuracy evaluation and validation between these two techniques . The comparison results show a good agreement between the 2D Fourier transform of DIPI interferogram and the 2D autocorrelation of DIH reconstructed in focus image . The DIH gives the reference result for the size measurement of the particles and we observe a maximum difference as low as 9 with the DIPI measurement . The backward arrangement of the dual beam interferometric particle imaging technique facilitates its further instrumental development and application to a variety of real circumstances e.g . solid fuel particles and ice crystals .
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Dual beam interferometric particle imaging DIPI is applied to irregular particle. Digital inline holography DIH and DIPI signals separate in channels of RGB image. The accuracy of size and shape measurement with DIPI is evaluated referring to DIH.
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S0022407319307095
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A detail ab initio study on the low lying states of ZnI is carried out by means of the multireference configuration interaction plus Davidson correction method . The spin orbit coupling effect of the low lying states is considered by utilizing relativistic effective core potential spin orbit operator . The potential energy curves are provided in the absence of SOC and presence of SOC . The spectroscopic constants of bound states are calculated which are in good agreement with the existing experimental results . With the help of the calculated SOC matrix elements the predissociation mechanism of 2
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The potential energies of 14 S states of ZnI are computed by MRCI method. The spin orbit coupling and 3d. correlation effects are included in the calculation. Spectroscopic constants of bound states of ZnI are evaluated. The predissociation mechanism of 2. of ZnI are analyzed. Radiative lifetimes of 2. and B. None. states of ZnI are determined.
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S0022407319307101
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The generalized laws of Snell Fresnel and energy balance are derived for the harmonic inhomogeneous plane waves that are incident upon a charged plane interface between two absorbing media . Excess surface charges impact the Fresnel coefficients by the surface conductivity which is the ratio of the surface current to the tangential component of the electric field . The surface current introduces an extra term of Joule heat loss in the generalized energy balance besides the usual terms of reflection transmission and interference . The reflection and transmission coefficients are calculated by the equations we derived and the validity of the results is verified by comparison with those calculated by the finite difference time domain method . In addition we identify a charge induced increase of Brewster angle for the harmonic homogeneous plane waves a significant influence of the incident angles for amplitude propagation vector on optical properties for HIPW and a strong increase of Joule heat loss due to the interaction between the incident HIPW and the surface charges .
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The generalized laws of Snell Fresnel and energy balance are derived for the harmonic inhomogeneous plane waves HIPW that are incident upon a charged and lossy plane interface. The surface conductivity is an extra factor to affect the reflection and transmission besides the optical constants of material. A new term of Joule heat loss is introduced due to the surface current. Pseudo Brewster angles increase with surface conductivities for the incident harmonic homogeneous plane waves. A strong increase of Joule heat loss happens due to the interaction between the HIPW and surface charges.
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S0022407319307149
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We explore a technique called class activation mapping to investigate how a Machine Learning architecture learns to classify particles based on their light scattering signals . We release our code and also find that different regions of the light scattering signals play different roles in ML classification . These regions depend on the type of particles being classified and on the nature of the data obtained and trained . For instance the Mueller matrix elements
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Used class activation maps CAM to quantify the discriminative importance of light scattering angles for our trained neural networks. The accuracy of our previous neural network was improved significantly using batch normalization max pooling and leaky ReLU activation function. Azimuthally averaged CAMs highlighted scattering angles with high discriminative importance for specific particle classes and configuration of Mueller matrix data input. CAMs can be used to inform scientists where to place detectors for strongest classification profile depending on the type of particles and measurement configuration.
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S0022407319307174
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The photonic jet generated by an ellipsiod illuminated by a plane wave is investigated . The open source software DDSCAT is used in our calculation . The influences of polarization ellipticity particle size the wavelength of the incident wave and the relative refractive index of the particle to the surrounding medium on the jet intensity waist width and length are analyzed . Numerical results show that we can manipulate the main characteristics of photonic jet by changing the above five parameters . These results of photonic jet can help us to achieve a nanoantenna with the function of generating a specific beam .
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Photonic jet generated by an ellipsoid is investigated using DDA. The influences of ellipticity particle size wavelength and refractive index are discussed. The. and FWHM of photonic jet were calculated under different parameters. The. and FWHM of photonic jet can be adjusted by choosing suitable parameters.
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S0022407319307216
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In the present study droplets of colloidal suspensions or emulsions are characterized using rainbow refractometry according to diameter relative refractive index and concentration of the dispersed phase . The position and angular spacing of the rainbow are used to retrieve the relative refractive index and droplet size . For the measurement of colloid concentration a novel method using the intensity ratio of the
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Simultaneous measurement of refractive index diameter and colloid concentration. Intensity ratio of. 2 and 0 scattering is used to measure colloid concentration. Measured ratio attenuations are verified by a Monte Carlo ray tracing simulation.
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S0022407319307241
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In generalized LorenzMie theory applied to structured beams the evaluation of beam shape coefficients constitutes a challenge . In this paper we propose to calculate BSCs of fundamental nondiffracting beams cosine beams Bessel beams Mathieu beams and parabolic beams . The aim of our method is the use of the Whittaker integral related to a scalar nondiffracting beam and well known angular spectrum decomposition . Also we exploit the relationship between solutions of scalar Helmholtz equation to expand the BSCs of nondiffracting beams in terms of higher order Bessel Beams BSCs . Some numerical simulations and discussions are given to validate our results .
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A new method of evaluating the beam shape coefficients BSCs in generalized LorenzMie theory for fundamental nondiffracting beams cosine beams Bessel beams Mathieu beams and parabolic beams is investigated. The relationship between solutions of scalar Helmholtz equation to expand the BSCs of nondiffracting beams in terms of higher order Bessel beams BSCs is exploited. For validation of the results numerical simulations and discussions are given.
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S0022407319307277
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We present a procedure for generating the parameters of the Hartmann Tran profile from purely first principles calculations . Starting from an absorber perturber interaction potential we calculate
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Fully ab initio calculation of Hartman Tran profile line shape parameters. Direct calculation of the Dicke parameter for atmospherically relevant species. Validation of velocity changing collisions model of the Hartmann Tran Profile. Validation of the temperature dependence model adopted in HITRAN2016.
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S0022407319307289
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The number of particle size distribution sampling points is an important factor to affect the accuracy of dynamic light scattering inversion . If the number of sampling points is not selected properly the accuracy of inversion results will be reduced or results will deviate seriously from the true value . To solve the problem combining non negative truncated singular value decomposition by studying the relationship between number of sampling points relative error of PSD and number of autocorrelation function channels it is concluded that the upper limit of optimal sampling points is limited by the number of ACF channels . Under different sampling points the study of RE of PSD and the residual of electric field ACF shows that there is a weak similarity between them . Then a criterion for determining the optimal number of sampling point is constructed . Finally a non negative constrained TSVD method for PSD adaptive sampling is proposed according to the upper limit condition of optimal number of sampling points and its determination criterion . Simulated DLS data for unimodal particles of 160 channels and bimodal particles of 120 channels were inverted under three noise levels of 110
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For NNTSVD accurate particle sizing rely on optimal sampling points selection. The number of sampling points must be less than the number of ACF channels. There is weak similarity between the relative error of PSD and the residual of ACF. Optimal sampling points can be achieved by minimum residual criterion.
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S0022407319307356
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To accurately simulate the effects of aerosols on the atmospheric radiation budget we here establish an aerosol optical parameterization scheme with high spectral resolution for radiative transfer model this scheme includes sulfate black carbon organic carbon dust and sea salt aerosols . The results of the 974 band scheme are compared with those obtained using a low resolution 17 band scheme . Our results show the 974 band scheme more accurate in its representation of the aerosols optical properties . The largest relative differences in the volume extinction coefficient K
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Establishment of an aerosol optical parameterization scheme with high spectral resolution 974 band . The new optical parameterization scheme 974 band with five types of aerosols are more accurate than those of 17 band especially at the wavelength of 1.91m 2.7m etc. The 974 band and 17 band schemes show daily mean direct radiative forcings due to all aerosols of. and. W m. at the surface and. and. W m. at the top of the atmosphere respectively.
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