微藻的辐射特性是研究微藻光捕获效率的非常重要的基本物性。小球藻细胞一般为非理想球形,存在内部结构,同时表面存在突起结构。本文基于随机高斯球模型对小球藻细胞形态进行建模,使用离散偶极子方法(DDA)对小球藻的光散射特性进行了模拟。分析了细胞核以及细胞粒径对散射特性的影响。结果表明:高斯随机球模型更接近小球藻的实际细胞形态,与理想的光滑球细胞模型相比,表面随机起伏的高斯随机球模型的散射相函数总体趋势与光滑球细胞模型相近,但其散射相函数后向部分更加平滑。在相同粒径下,考虑细胞核与忽略细胞核相比,前者的衰减截面显著大于后者,但吸收截面没有明显差别。
The radiative properties of microalgae plays a significant role in the study of its light trapping efficiency.In general,the morphology of Chlorella is not spherical and there are internal structures as well as surface roughness.This paper used the stochastic Gaussian sphere to model the cell morphology of Chlorella,and applied the discrete dipole approximation(DDA) to simulate the scattering properties of Chlorella.The influences of cell nucleus and cell diameter on cell scattering properties are analyzed.The results show that,stochastic Gaussian sphere is more close to the morphology of Chlorella.As compared to the ideal sphere model,the distribution of the scattering phase function of the stochastic Gaussian sphere generally shows similar trend,but at the backward direction,the scattering phase function is smoother.At the same cell diameter,as compared to the case without nucleus,the extinction cross section of the case with nucleus is significantly larger than the former,but the absorption cross section of the two cases show little difference.