挥发性和半挥发性有机物向二次有机气溶胶转化的机制*

从近20年二次有机气溶胶形成机制的研究成果可发现，挥发性和半挥发性有机物转化为二次有机气溶胶的主要物理化学过程可概述为光化学氧化机制、成核过程、凝结和气/粒分配机制以及非均相反应机制。本文系统总结了这些物理化学反应的发生过程及其影响因素，重点阐述了异戊二烯和甲苯同系物的光氧化机制，总结了二次有机气溶胶气/粒分配的两种理论--吸收机制和吸附机制，评述了发生在颗粒相上的非均相反应对二次有机气溶胶形成的重要作用。最后，对二次有机气溶胶形成机制研究的发展方向进行了展望。

Formation Mechanism of Secondary Organic Aerosols from the Reaction of Volatile and Semi-Volatile Compounds

The main physical-chemical processes of secondary organic aerosols (SOA) formation from volatile and semi-volatile compounds can be summarized as photooxidation mechanism, nucleation process, condensation, gas/particle partition and heterogeneous reaction mechanism according to the research about SOA formation mechanism of the last twenty years. These physical-chemical processes and their influence factors are discussed in detail in this paper. Isoprene and toluene and its homologs are focused to illustrate the photooxidation of alkene and aromatic compounds. Two important theories of gas/particle partition, absorption mechanism and adsorption mechanism are analyzed. Heterogeneous reaction is proposed for its substantial effect for SOA formation. At last, some prospects for the study direction of the formation mechanism of SOA are given. Contents
1 Introduction
2 Main physical and chemical processes of SOA formation
3 Photooxidation mechanism
3.1 Photooxidation mechanism of alkenes
3.2 Photooxidation mechanism of aromatic compounds 
4 Nucleation process, condensation, gas/particle partition 
5 Heterogeneous reaction mechanism 
6 Prospects