Optical Emissions from Photoexcitation of Atmospheric Radicals and Molecules in the Gas Phase and on Aerosol Surfaces

气相和气溶胶表面上的大气自由基和分子的光激发光发射

基本信息

批准号：
9016731
负责人：
Long Lee
金额：
$ 10万
依托单位：
San Diego State University Foundation
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1991
资助国家：
美国
起止时间：
1991-04-01 至 1993-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9016731&HistoricalAwards=false
关键词：
Optical Emissions Photoexcitation Atmospheric Radicals

项目摘要

The project is devoted primarily to atmospheric aerosols. Laboratory experiments will probe the conditions under which aerosols of ammonium sulfate and ammonium bisulfate can be formed in the gas phase from ammonia, sulfur trioxide and water vapor. The aerosols will be produced by mixing the reacting gases in a flow tube. Particle-size distributions of the resulting aerosols will be deduced from measurements of ultraviolet light scattering. Experiments will assess the possibility of chemically identifying such aerosols by observing light emitted by them when they are exposed to laser beams of variable wavelength and intensity. Variations of these experiments will test possibilities of separately detecting chemical species adhering to the surfaces of the aerosol particles. Similar experiments will be conducted on the formation of ammonium nitrate aerosols from ammonia, water vapor, nitric acid and/or nitrogen dioxide. The experiments will be useful for better understanding of conditions under which these aerosols are formed in both the natural and the perturbed atmosphere. The feasibility of measuring the aerosols under field conditions will be explored. Experiments aimed at detecting chemical species adhering to the aerosol surfaces are designed to reveal any unsuspected surface- chemical properties of the aerosols, by virtue of which they might influence the chemistry of the gas phase.

该项目主要致力于大气气溶胶。实验室实验将探讨氨、三氧化硫和水蒸气在气相中形成硫酸铵和硫酸氢铵气溶胶的条件。通过在流管中混合反应气体来产生气溶胶。所得气溶胶的粒径分布将从紫外光散射的测量中推断出来。实验将通过观察气溶胶暴露于不同波长和强度的激光束时发出的光来评估化学识别此类气溶胶的可能性。这些实验的变体将测试单独检测附着在气溶胶颗粒表面的化学物质的可能性。类似的实验将针对由氨、水蒸气、硝酸和/或二氧化氮形成硝酸铵气溶胶进行。这些实验将有助于更好地了解这些气溶胶在自然和扰动大气中形成的条件。将探讨在现场条件下测量气溶胶的可行性。旨在检测粘附在气溶胶表面的化学物质的实验旨在揭示气溶胶的任何未预料到的表面化学性质，从而它们可能影响气相的化学性质。