二次气溶胶颗粒静/动态观测实验台建设与研究

In this study, we will build an experimental system for aerosol particle research, by which we can perform statistical or dynamic measurements of the secondary aerosol particles, especially the microscopic physical characteristics and the growth process of the acculation mode particles (with diameter about 0.1-5um). The main research contents include : (1) Measuring the physical characteristics (such as geometrical size, aspect ratio, number density distribution, effective density and compactness) of natural atmospheric aerosol particles under the statistic condition, observing the particle growth along with the environmental huminity or temperature change; (2) Measuring the dynamic properties and the change of the physical properties when the particles are suspended in air or moving with air flow, studying the effect of particle collision and accumulation on the particle growth. The studying and results of this project will advance the development of the micro/nanoscale flow measurement technique, achieve the purpose of describing aerosol particle's physical characteristics, and help people understand well the micro mechanism of atmospheric pollution particles, and finally provide experimental evidence for the theoretical study of the air quality model.

本申请拟研制气溶胶颗粒物实验测试平台，在静、动态条件下观测二次气溶胶，尤其是积聚模态颗粒(粒径0.1-2um)的微观物理特征及生长过程。研究内容包括：(1)在静态条件下，进行自然大气污染颗粒物物理参数表征(包括几何尺寸、长细比、数密度分布、有效密度、密实度等)，且在改变环境湿度或温度下观测颗粒生长；(2)在动态条件下，即颗粒物悬浮或流动状态下，观测颗粒物运动过程及形貌等物理参数改变，研究粒子碰并、凝聚等效应对颗粒物生长的影响。此项目的研究，不仅将促进微纳尺度气相/固相流场观测技术的发展，而且能对真实雾霾粒子表征，并深化大气污染颗粒物形成微观机理的认识，为空气质量模式理论提供实验依据。

本项目研制了气溶胶颗粒物实验测试平台基于显微观测技术对大气气溶胶颗粒的几何及物理属性进行观测。主要的研究结果包括：(1) 完成静态观测，发展了显微观测方法及气溶胶颗粒物性参数程序(Program of Aerosol particle Physical Coefficients, APC)。基于灰度梯度法等图像处理方法，可以快速、准确的测量0.1微米以上的雾霾气溶胶颗粒的属性。（2）与现场采样及遥感观测结合，应用于甘肃民勤、张裕及新疆喀什地区的气溶胶测量及分析。(3) 开展了气溶胶观测风洞的建设，为气溶胶颗粒动态演化实验测量打下了良好的基础。本项目的研究，不仅将促进微纳尺度气相/固相流场观测技术的发展，而且能对真实雾霾粒子表征，并深化大气污染颗粒物形成微观机理的认识，为空气质量模式理论提供实验依据。