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ELUCIDATION OF GENERATION AND GROWTH MECHANISMS OF SECONDARY PARTICLES

阐明二次粒子的生成和生长机制

基本信息

批准号：
14048216
负责人：
OKUYAMA Kikuo
金额：
$ 18.75万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

For assessment and prevention of the impact of secondary aerosol particles on atmospheric environment and human health, particle generation mechanism and methods for an accurate measurement of cluster ion and nanoparticles were investigated in this report.1. MEASUREMENT OF AEROSOL SIZE DISTRIBUTIONIn order to measure the particle size distribution of atmospheric aerosols from about 1nm to some microns, the differential mobility analyzer (DMA), mixing-type condensation nucleus counter (M-CNC), Faraday cup electrometer (FCE) were improved. Especially, combination of newly developed particle size magnifier (PSM) and conventional CNC made possible to measure number concentration of nanoparticles and ions down to 3nm in atmospheric and low pressure conditions. Moreover, in order to charge aerosol particles, alternative soft X-ray photoionizer was newly developed.2. DEVELOPMENT OF THE CARBON-CONTAINING AEROSOL MEASURING METHODFor an improvement of measuring technique for OC (organic carbon) … More and EC (elemental carbon) of aerosols, fundamental study for optical technique and comparison of OC concentrations with sampling methods were performed. For the improvement of carbonaceous particle measurement, standard filters with EC and OC reference particles were fabricated by a spray-drying method. The composite particles of SiO2/Carbon black were also prepared and the optical properties were also evaluated.3. NUCLEATION AND GROWTH OF NANO-PARTICLES BY ION-INDUCED NUCLEATIONExperimental system, which consists of a drift tube ion mobility spectrometer/mass spectrometer and a cluster-DMA combined with FCE, was developed to investigate the relationship between cluster ions and nanoparticles. This system enabled mass spectrometric measurement of ions and high-resolution mobility spectrometric measurements of ions and ultrafine particles generated by ionizing radiation. Since gaseous pollutants have significant effects on atmospheric aerosol particle formation, effects of NO_2, one of main atmospheric gaseous pollutants, on particle formation in SO_2/H_2O/air mixtures irradiated by α-ray was experimentally investigated and relative importance of ion-induced nucleation to homogeneous nucleation was discussed. Less

为了评估和预防二次气溶胶颗粒物对大气环境和人体健康的影响，本文研究了二次气溶胶颗粒物的产生机理和精确测量团簇离子和纳米颗粒物的方法.气溶胶粒径分布的测量为了测量从1 nm到几微米的大气气溶胶粒径分布，对微分迁移率分析仪（DMA）、混合式凝结核计数器（M-CNC）、法拉第杯静电计（FCE）进行了改进。特别是，新开发的粒度放大器（PSM）和传统的CNC相结合，使得有可能在大气和低压条件下测量纳米粒子和离子的数浓度低至3 nm。此外，为了对气溶胶粒子进行充电，新开发了替代型软X射线光电离器.含碳气溶胶测量方法的发展--有机碳测量技术的改进 ...更多信息和EC（元素碳）的研究，光学技术的基础研究以及OC浓度与采样方法的比较。为了提高碳质颗粒的测量，用喷雾干燥法制备了含有EC和OC参比颗粒的标准过滤器。制备了SiO2/炭黑复合粒子，并对其光学性能进行了评价.离子诱导成核法研究纳米粒子的成核与生长建立了一套由漂移管离子迁移谱仪/质谱仪和原子团簇-DMA结合FCE组成的实验系统，用于研究原子团簇离子与纳米粒子之间的关系。该系统能够对离子进行质谱测量，并对电离辐射产生的离子和超微粒子进行高分辨率迁移率光谱测量。由于气态污染物对大气气溶胶粒子的形成有重要影响，本文实验研究了大气主要气态污染物之一NO_2对α射线辐照SO_2/H_2O/空气混合气中粒子形成的影响，并讨论了离子诱导成核与均匀成核的相对重要性。少