The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of opti...The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers （PWIs） in addition to the de- tection of forward-scattering optical properties.展开更多
As the simplest neutral triatomic reaction system,the H+H_(2)bimolecular reaction and its isotope variants are critically important for understanding elementary chemical reactions at the microscopic level.A high-resol...As the simplest neutral triatomic reaction system,the H+H_(2)bimolecular reaction and its isotope variants are critically important for understanding elementary chemical reactions at the microscopic level.A high-resolution crossed molecular beams method was used in this work to explore the H+HD→H_(2)+D elementary chemical reaction at a collision energy of 2.20 eV.The product D atoms were detected using the 1+1′(vacuum ultraviolet and ultraviolet laser)D-atom near-threshold ionization technique.Differential cross sections with vibrational and rotational state resolutions were experimentally acquired,covering the full scattering angular range.Particularly,fast forward oscillations were presented at several rovibrational states,such as v’=0,j’=10 and v’=1,j’=5.Our analysis shows that scattering partial waves close to J=36 mainly contribute to the oscillatory structures.Moreover,the branching ratios of the odd j’and even j’were also derived,revealing that the rotational populations of the H_(2)(v’=0)co-product strongly depend on the nuclear spin statistics.展开更多
基金supported mainly by the China Meteorological Administration under Grant GYHY200806031supported by the Chinese Academy of Sciences under Grant XDA05040302
文摘The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers （PWIs） in addition to the de- tection of forward-scattering optical properties.
基金supported by the National Natural Science Foundation of China(22125302,21327901).
文摘As the simplest neutral triatomic reaction system,the H+H_(2)bimolecular reaction and its isotope variants are critically important for understanding elementary chemical reactions at the microscopic level.A high-resolution crossed molecular beams method was used in this work to explore the H+HD→H_(2)+D elementary chemical reaction at a collision energy of 2.20 eV.The product D atoms were detected using the 1+1′(vacuum ultraviolet and ultraviolet laser)D-atom near-threshold ionization technique.Differential cross sections with vibrational and rotational state resolutions were experimentally acquired,covering the full scattering angular range.Particularly,fast forward oscillations were presented at several rovibrational states,such as v’=0,j’=10 and v’=1,j’=5.Our analysis shows that scattering partial waves close to J=36 mainly contribute to the oscillatory structures.Moreover,the branching ratios of the odd j’and even j’were also derived,revealing that the rotational populations of the H_(2)(v’=0)co-product strongly depend on the nuclear spin statistics.
