大气颗粒物显微轮廓分形与源解析

为监测大气颗粒物的来源,根据静电吸附原理设计大气颗粒收集装置采集大气颗粒物,通过光学显微放大技术和图像分析方法,得到源颗粒的轮廓分形维数值,结合采样点周边的实际情况,分析和对比各源颗粒的轮廓分形维数值,确定颗粒部分来源;并采用偏光显微镜观察各源颗粒的偏光特征,协同确定大气颗粒的具体来源。结果表明,大气颗粒具有分形特征,其很多特性均与其分形特征有关;采用大气颗粒的轮廓曲线分形维数值作为降尘颗粒来源的辨析参数是可行的,轮廓曲线的分形维数值能很好地表达颗粒的结构形态,特定颗粒源的分形维数值具有一定的范围;将轮廓曲线的分形维数值与各源颗粒的偏光特征相结合,对颗粒来源的辨识准确率在90%以上。

Micro-outline Fractal and Origin Analysis of Atmospheric Particles

To inspect the origin of atmospheric particles,the atmospheric particles were collected by the collecting device of atmospheric particles designed by electrostatic adsorption principle.By the optical micro-magnification technique and the image analysis method,the outline fractal dimension values of origin particles were obtained.Combined with the surrounding practical circumstances of sampling points,part origin of the atmospheric particles was gained by analyzing and comparing the fractal dimension values of each origin particle.The polarization property of each origin particle was investigated by polarization microscope,which could be coordinately used to distinguish the specific origin of the atmospheric particles.The results show that the atmospheric particles have fractal properties,many properties of the particles are corresponding to the fractal properties.It is feasible that the outline fractal dimension values of atmospheric particle are used as discrimination parameters of dust particles origin.The outline fractal dimension values can express the morphology of particles well.The fractal dimension value of specific origin particle has a certain scope.Combining the outline fractal dimension values with the polarization property of origin particles,the identification accuracy of the particles origin is more than 90%.