Dynamics of Pressure-Dependent Atmospheric Reactions

压力相关大气反应的动力学

• 批准号: 0344102
• 负责人: John Barker
• 金额: $ 50万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-15 至 2008-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0344102&HistoricalAwards=false
• 关键词: Dynamics; Pressure; Dependent; Atmospheric; Reactions

This study involves the use of computational methods to investigate a potentially important pathway for association reactions, being those chemical reactions in which two species combine to form a metastable intermediate species before dissociating to the final products. The potential pathways involve the ways in which excess energy is transferred to the bath gas. The standard Energy Transfer Mechanism (ETM) has been employed successfully to explain a number of atmospherically important association reactions. The alternative process is the Chaperone Mechanism (CM) that could explain why some association reactions have multiple channels or unusual dependence on concentrations of non-reacting species (for example, water vapor). A detailed framework for dealing with the CM component of association reactions will be developed, and an investigation of the utility of using the rate of quenching of vibrationally excited species as an alternative to using the high pressure limiting association rate coefficient will also be undertaken. Finally, a computer program will be developed that incorporates the key findings of this study and will be freely distributed to all interested parties. The results of this research, while relevant to atmospheric chemistry, will also benefit researchers studying combustion, planetary atmospheres, and other chemically reacting systems.

这项研究涉及使用计算方法来研究缔合反应的潜在重要途径，即两种物质在解离为最终产品之前结合形成亚稳态中间物质的化学反应。 潜在的途径涉及将多余能量转移到浴气体的方式。 标准能量传递机制（ETM）已成功用于解释许多对大气重要的缔合反应。 另一种过程是伴侣机制 (CM)，它可以解释为什么某些缔合反应具有多个通道或对非反应物质（例如水蒸气）浓度的异常依赖。 将开发处理缔合反应的 CM 部分的详细框架，并且还将研究使用振动激发物质的猝灭速率作为使用高压限制缔合速率系数的替代方案的效用。 最后，将开发一个包含本研究主要发现的计算机程序，并将免费分发给所有感兴趣的各方。 这项研究的结果虽然与大气化学相关，但也将使研究燃烧、行星大气和其他化学反应系统的研究人员受益。