U.S.-Korea Cooperative Research on NMR Phenomena in Solid H2and D2

美韩合作研究固体H2和D2中的NMR现象

• 批准号: 8820518
• 负责人: Horst Meyer
• 金额: $ 1.44万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8820518&HistoricalAwards=false
• 关键词: U.S.; Korea; Cooperative; Research; NMR

This proposal requests funds to permit Dr. Horst Meyer, Department of Physics, Duke University, to pursue with Dr. Insuk Yu, Department of Physics, Seoul National University, for 24 months, an experimental and theoretical nuclear magnetic resonance (NMR) study of solid hydrogen and deuterium (H , HD, and D ). The research 2 2 will focus on (1) a better understanding of the NMR "solid echo" pattern in D single crystals, (2) a systematic study of 2 "stimulated echoes" in solid H and D that can give valuable 2 2 information on the molecular fluctuation rates, and (3) understanding the anisotropy of the NMR shift in the proton spectrum between H and HD. Solid H and D are each made up 2 2 2 of two molecular species forming a homogeneous mixture. These two species have rotational angular momentum (J=1) and (J=0). Mixtures of these species can be prepared in any proportion. The J=1 molecules have an electric quadrupole moment, while those with J=0 are spherically symmetric. Anisotropic forces between the J=1 particles produce orientational ordering at temperatures below about 3 degrees Kelvin. This ordering process in these molecular solids, analogous to dilute magnetic systems, is a function of the J=0 concentration. Above a critical concentration of J=1 equal to about 53 mole percent, there is a well defined transition to an ordered state. The research will attempt to provide a more quantitative understanding of the orientation ordering process in H , HD, and D and to explain anomalous behavior observed in 2 2 previous NMR studies of solid hydrogen. The U.S. and Korean collaborators are highly respected scientists who have records of successful research in the field of this project. Their collaboration in the past has led to several joint publications. Because Seoul National University does not yet have low temperature facilities, the work in Korea will be mostly theoretical, while that at Duke University will be both experimental and theoretical. The present project will allow the collaborators to combine their talents and interests for mutual benefit. This project is relevant to the objectives of the U.S.-Korea Cooperative Science Program which seeks to increase the level of cooperation between U.S. and Korean scientists and engineers through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit. Korean participation in the project, including Dr. Yu's visits to Duke University, is supported by the Korea Science and Engineering Foundation (KOSEF).

这项提案要求获得资金，以允许杜克大学物理系Horst Meyer博士与首尔国立大学物理系Yu Insuk博士一起进行为期24个月的固体氢和氘(H、HD和D)的实验和理论核磁共振(核磁共振)研究。研究2 2将集中于(1)更好地理解D单晶中的核磁共振“固体回波”模式，(2)系统地研究了固体H和D中的2个“受激回波”，它可以给出关于分子涨落速率的有价值的2 2信息，以及(3)了解H和HD之间质子谱中核磁共振位移的各向异性。固体H和D分别由两个分子物种组成2 2 2，形成均匀的混合物。这两种物质具有转动角动量(J=1)和(J=0)。这些物种的混合物可以按任何比例制备。J=1分子具有电四极矩，而J=0分子是球对称的。J=1粒子之间的各向异性力在低于3开尔文的温度下产生取向有序。这些分子固体中的这种有序化过程，类似于稀磁系统，是J=0浓度的函数。在J=1的临界浓度等于约53摩尔百分数以上，存在到有序状态的明确转变。这项研究将试图对H、HD和D中的取向有序化过程提供更定量的理解，并解释在2 2以前的固体氢核磁共振研究中观察到的反常行为。美国和韩国的合作者都是备受尊敬的科学家，他们在该项目领域有成功研究的记录。他们过去的合作导致了几份联合出版物的出版。由于首尔国立大学还没有低温设施，韩国的工作将主要是理论上的，而杜克大学的工作将既是实验又是理论。本项目将允许合作者将他们的才华和兴趣结合在一起，实现互利共赢。该项目与美韩合作科学计划的目标相关，该计划旨在通过交流科学信息、想法、技能和技术以及通过在互利问题上的合作来提高美国和韩国科学家和工程师之间的合作水平。韩国参与该项目，包括Yu博士对杜克大学的访问，得到了韩国科学与工程基金会(KOSEF)的支持。