利用近前向散射图样识别单粒子形状的理论研究

近前向光学散射图样可以用来表征颗粒物的形状.基于球形芽孢杆菌、枯草芽孢杆菌、类鼻疽伯克氏菌的回转长椭球模型, 采用离散偶极子近似方法, 通过模拟3个不同方位探测器接收的散射光强响应信号, 讨论了非球形生物气溶胶颗粒的形状对前向角分辨光强的影响.结合球形指数反演算法, 在一定取向条件下, 前向5°–20° 内角分辨散射光强具有识别长形颗粒物和非长形颗粒物的能力.该研究可以为颗粒物形态测量仪器设计以及快速检测有害生物气溶胶提供依据.

Shape classification of single aerosol particle using near-forward optical scattering patterns calculation

Particle shapes can be distinguished by the properties of near-forward optical scattering patterns of particles. The discrete dipole approximation method is used to calculate the light scattering patterns of Bacillus sphaericus, Bacillus subtilis, Burkholderia pseudomallei based on their prolate spheroid models. Shape dependence of forward angle-resolved light scattering intensity for nonspherical biological aerosol particles is discussed by simulating their light scattering response of three detectors located in different azimuthal range. Combined with sphericity index method, forward small angle (5°–20°) angle-resolved light scattering intensity has the ability to identify the elongated particles and non-elongated particles under certain orientation conditions. This study can help not only design particle morphology measurement instrument but also detect harmful biological aerosol rapidly.