核壳结构粒子与群粒子光学散射特性研究  

Optical Scattering Properties of Particles and Group Particles with Core-Shell Structure

作　　者：毛前军[1] 杨开雁 Mao Qianjun;Yang Kaiyan(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,Hubei,China)

机构地区：[1]武汉科技大学城市建设学院,湖北武汉430065

出　　处：《激光与光电子学进展》2024年第5期514-521,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51876147)。

摘　　要：为探究近红外波段下气溶胶粒子的散射特性,基于离散偶极子近似法,对黑碳和硫酸盐气溶胶内混合核壳结构粒子及同种气溶胶粒子的2种假设结构的光学散射特性进行研究。编译构建以黑碳为核、硫酸铵为壳的核壳结构粒子模型,模拟计算特定入射方向的入射波长(875、1020、1640、2000 nm)下粒子的消光效率因子、散射效率因子、吸收效率因子、不对称因子及单次散射反照率随有效粒径的变化。数值计算结果表明:在同一入射波长下,随着有效粒径的增大,单核核壳粒子、二核团簇粒子、三核团簇粒子的消光、散射、吸收效率因子主要呈先增后减趋势,且3种粒子的散射、消光效率因子相差不超过10%。随着核粒子数增加,粒子结构半径增大,效率因子峰值后移。在4个波长下,多核团簇粒子的不对称因子平均比单核核壳粒子大0.1777、0.1960、0.2900和0.3131,而2种多核粒子的不对称因子平均仅相差0.096。在有效粒径相同的情况下,单核核壳粒子的单次散射反照率基本高于多核粒子,波长越大差异越明显。该研究结果可对复杂大气环境下气溶胶粒子的光学散射特性、污染物及气候效应监测等领域的分析提供一定的参考价值。To explore the scattering characteristics of aerosol particles in the near infrared band,the optical scattering characteristics of two hypothetical structures having mixed core-shell particles and the same aerosol particles in black carbon and sulfate aerosols are investigated by using discrete dipole approximation.A core-shell particle model with black carbon as the core and ammonium sulfate as the shell is constructed to simulate the extinction efficiency factor,scattering efficiency factor,absorption efficiency factor,asymmetry factor,and single scattering albedo of the particles at several incident wavelengths(875,1020,1640,and 2000 nm)in specific incident directions with varied effective particle sizes.The numerical results show that the extinction,scattering,and absorption efficiency factors of mononuclear shell particle,two-core cluster particle,and three-core cluster particle initially increase and then decrease with an increasing effective particle size at the same incident wavelength.In addition,the differences in the scattering and extinction efficiency factors of the three particles are less than 10%.With an increase in the number of nuclear particles,the radius of the particle structure increases,and the peak of the efficiency factor shifts backward.At the four different wavelengths,the asymmetry factor of the multi-nucleated cluster particles is 0.1777,0.1960,0.2900,and 0.3131 larger than that of the mononuclear shell particles on average,and the average difference between the asymmetry factors of the two types of multi-nucleated particles is 0.096.At the same effective particle size,the single scattering albedo of mononuclear shell particles is higher than that of multi-core particles;the larger the wavelength,the more distinct is the difference.The results are useful for further analyses of the optical scattering characteristics of complex atmospheric aerosol particles and monitoring of pollutants and climate.

关 键 词：红外波段 气溶胶粒子 核壳粒子 离散偶极子近似法 散射与吸收 

分 类 号：P407.6[天文地球—大气科学及气象学]