分形结构对随机取向烟尘团簇粒子光散射特性的影响  

The influence of the fractal configuration on the light scattering properties of randomly oriented soot clustered agglomerates

作　　者：类成新[1] 冯东太[1] 吴振森[2] 

机构地区：[1]山东理工大学理学院,淄博255049 [2]西安电子科技大学理学院,西安710071

出　　处：《原子与分子物理学报》2012年第1期141-146,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(60771038)

摘　　要：利用蒙特卡罗方法对不同分形维数和分形前向因子的随机取向烟尘团簇粒子的分形结构进行了仿真,采用离散偶极子近似(DDA)方法对随机取向烟尘团簇粒子的缪勒矩阵元进行了数值计算,并与球形粒子模型进行了比较,深入探讨了烟尘团簇粒子的分形维数和分形前因子对其散射特性的影响.研究表明,等效球形粒子的光散射特性与随机取向烟尘团簇粒子的光散射特性存在很大差别,并且此差别随着团簇粒子的分形维数以及分形前向因子的增大而减小;分形维数对表征团簇粒子散射特性的缪勒矩阵元的影响在一定散射角范围内均比较明显,分形前向因子对团簇粒子的缪勒矩阵元角分布的影响与分形维数的影响类似,不过其影响相对分形维数较弱.The Monte Carlo method is used to simulate the structures for a wide variety of fractal-like soot clustered agglomerates in random orientation, and the Mueller matrices of soot clustered agglomerates are calculated based on the discrete dipole approximation （DDA） method, the results are compared with those obtained from the spherical model. The influence of the fractal dimension and prefactor on the light scattering characteristics of randomly oriented soot clustered agglomerates is mainly discussed. It is shown that the results for the equivalent spherical particles differ profoundly from those calculated for soot clustered agglomerates, and the discrepancies between them change little with the increase of the fractal dimension and prefactor; the influence of the fractal dimension on the Mueller matrices of randomly oriented soot clustered agglomerates is obvious in certain angular regions; the influence of the fractal prefactor on the Mueller matrices is similar but visibly weaker.

关 键 词：光散射特性 离散偶极子近似方法 烟尘团簇粒子 分形维数 分形前向因子 

分 类 号：P422.3[天文地球—大气科学及气象学]