随机取向内外混合凝聚粒子辐射特性  

Radiative properties of internal/external mixture of agglomerates in random orientation

作　　者：类成新[1] 吴振森[2] 冯东太[1] 

机构地区：[1]山东理工大学理学院 [2]西安电子科技大学物理与光电工程学院

出　　处：《红外与激光工程》2013年第10期2692-2696,共5页Infrared and Laser Engineering

基　　金：国家自然科学基金(60771038;61172031)

摘　　要：采用离散偶极子近似方法对随机取向混合凝聚粒子在内外混合状态下的光学截面、单次散射反照率以及非对称因子等辐射特性参量进行了数值计算,详细讨论了混合方式、混合比等因素对混合凝聚粒子辐射特性的影响。研究表明,混合凝聚粒子的混合方式对非对称因子的影响非常大,对散射截面和单次散射反照率的影响比较大,但是对吸收和消光截面的影响不明显。随着凝聚粒子中基本粒子粒径和数量的增大,非对称因子、散射截面以及单次散射反照率受混合方式的影响变得愈加明显。此外,混合比的变化对不同混合状态下的凝聚粒子的辐射特性参量均存在不同程度的影响,并且此影响随着基本粒子粒径和数量的变化而显著变化。混合比相同情况下,所有外混合凝聚粒子的散射截面均大于内混合凝聚粒子的散射截面,而单次散射反照率却相应减小。The discrete dipole approximation method was used to compute the radiative characteristic parameters including the optical cross-sections, single-scattering albedo and asymmetrical parameter for a variety of mixed agglomerates in different mixing states at a visible wavelength 0.55μm. It is shown that the influence of the mixing states on the asymmetrical parameter is very great, and that on the scattering cross section and single-scattering albedo is heavy, while that on the absorption and extinction cross sections is not obvious. The influence of mixing patterns on the asymmetrical parameter, scattering cross section and single-scattering albedo is becoming more obvious with the increase of the size of agglomerates. The mixture ratios has an obvious effect on the radiative characteristic quantities of agglomerates in internal and external mixing states, and the effect varies with the monomer diameters, and number of monomers in the agglomerates. The scattering cross-sections of external mixture of agglomerates are larger than those of their internally mixed counterparts, but the single-scattering albedo decreases accordingly at the same mixture ratios.

关 键 词：混合凝聚粒子 辐射特性 Bruggeman有效介质理论 离散偶极子近似方法 

分 类 号：P401[天文地球—大气物理学与大气环境] P422.31[天文地球—大气科学及气象学]