Gas-to-Particle Conversion of Polluted Gas by Nucleation

大气中分散的亚微米细颗粒物（气溶胶）会造成大气污染、人类健康问题和地球温室效应。然而，作为大气环境中细颗粒生成过程的重要的气体-颗粒转化过程迄今尚未得到充分评价，因为这些过程受成核现象支配。因此，在本研究中，通过日本、美国和欧洲的研究人员的合作，研究了从大气污染调查的观点来看特别重要的大气中的微量杂质气体向微粒的转化过程，以及微粒和气体的动力学行为和沉积过程。本文用装有放射源的小电离室和绝热膨胀室研究了NO_x '>、SO_x'>、H_2O等二元和三元气体体系的成核现象 ...更多信息 ber.通过对团簇和颗粒尺寸分布的测量，阐明了成核速率和离子对成核增强的影响。根据现代成核理论建立的理论模型，讨论了离子增强成核的机理，为解释实验结果提供了可能。推导了描述生成颗粒生长过程、气体和颗粒输运沉积过程的通用动力学方程和对流扩散方程。方程的数值计算结果可以解释通过化学反应产生颗粒的实验和使用气体和颗粒悬浮的小空间的实验的结果。因此，通过本研究的实验和理论研究所获得的结果被认为是有用的，用于构建一个物理-数学模型来评估细颗粒物在环境中的影响。少

A dispersed system of submicron, fine particles in the atmospheric air (aerosol) causes atmospheric pollution, problems on human health and the greenhouse effect to the earth. However, the processes of gas-to-particle conversion which are important as the processes of fine particle generation in the atmospheric environment have not been fully evaluated to date since these are governed by nucleation phenomena. Therefore, in this study, the conversion processes of trace impurity gas in the atmosphere into fine particles, and dynamic behavior and deposition processes of fine particles and gas, which are important especially from the viewpoint of investigating atmospheric pollution, were studied through collaboration among researchers in Japan, U.S.A.and Europe.In the experiments of this study, nucleation phenomena in binary and ternary gas systems including NO_<x'>, SO_<x'>, H_2O,etc.were investigated using a small chamber equipped with a radioactive source and an adiabatic expansion cham … More ber. The rate of nucleation and the effect of ions on the enhancement of nucleation were then clarified from the measurements of the size distributions of clusters and particles. The mechanisms of the enhancement of nucleation by ions were discussed with a theoretical model based on the modem nucleation theories, which made it possible to explain the experimental results. The general dynamic equation and convection-diffusion equation were also derived to describe the growth processes of generated particles, and the transport and deposition processes of gas and particles. The results of numerical calculation of the equations could explain the results of experiments on particle generation via chemical reaction and experiments using a small space where gas and particles are suspended. Accordingly, the results obtained through the experiments and theoretical investigation of this study are considered useful for constructing a physico-mathematical model for evaluating the effect of fine particles in the environment. Less