The Short-Time Dynamics of Liquids

液体的短时动力学

• 批准号: 9417546
• 负责人: Richard Stratt
• 金额: $ 41.4万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-01-15 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9417546&HistoricalAwards=false
• 关键词: Short; Time; Dynamics; Liquids

Richard Stratt, Brown University, is supported by a grant from the Theoretical and Computational Chemistry Program to continue his theoretical research in the short time dynamics of liquids. Stratt seeks to interpret recent spectroscopic data obtained from time-dependent-Stokes-shift measurements of solvation dynamics as well as Fourier transform Raman (Optical Kerr effect) spectra of neat liquids in terms of the instantaneous normal mode (INS) theory of the liquid vibrations. Two fundamentally disparate research directions to be undertaken are: 1) to explore the ways in which INS analysis can assist in the interpretation of ultrafast spectroscopic experiments; and 2) to find ways of extending the workable time span into the nonlinear regime as much as possible, and to discover where the true limits of the technique lie. The effects of nonlinearity will be studied by examining the time evolution, both via exact simulation and somewhat more analytically, by considering the nonlinearity formally as a perturbation. A significant fraction of what one thinks about as chemistry takes place in solution, and chemical processes often look far different in a liquid environment than they would if the molecules were completely isolated. Just what the origins of these differences are, and precisely how these distinctions arise from the molecular properties of the solvent are questions that have been pursued repeatedly with each new generation of spectroscopic technique. Recent theoretical progress in elucidating the concept of linear excitations in liquids suggests that it may indeed be useful to think in terms the short time evolution in the liquid-state being governed by a set of liquid vibrations -- the so-called instantaneous normal modes of the liquid. The major purpose of Stratt's research is to see if this theoretical construct can lead to interpretation of recent results obtained from ultrafast spectroscopy, and to provide a molecular level interpretation of the structure and dynamics of the liquid state.

理查德斯特拉特，布朗大学，是由赠款的支持， 理论和计算化学计划，继续他的 液体短时动力学的理论研究。 斯特拉特 试图解释最近的光谱数据， 溶剂化动力学的时间依赖性斯托克斯位移测量以及 本文研究了纯液体的傅里叶变换拉曼（光学克尔效应）光谱， 液体的瞬时简正模（INS）理论 震动 两个根本不同的研究方向 进行的工作是：1）探索INS分析可以帮助 在超快光谱实验的解释;和2）， 设法将可行的时间跨度扩展到非线性状态 尽可能多的，并发现真正的限制， 技术谎言 非线性的影响将通过检查 时间的演变，通过精确的模拟， 在分析上，通过将非线性形式上视为 扰动 当化学反应发生时， 在溶液中，化学过程在液体中看起来很不一样 比分子完全分离时的环境更好。 这些差异的起源是什么，以及这些差异是如何产生的。 由溶剂的分子性质引起的区别是 每一代人都在反复追求的问题， 光谱技术 最近的理论进展，在阐明 液体中线性激发的概念表明，它可能确实是 用液态的短时间演化来思考 由一系列液体振动控制--所谓的 液体的瞬时简正模式。 斯特拉特的主要目的是 研究是为了看看这个理论结构是否会导致 从超快光谱学获得的最新结果的解释， 并提供结构的分子水平解释， 液态的动力学。