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Magnetically Induced Rotating Rayleigh-Taylor Instability
Published on: March 3, 2017
液态水中的旋转运动是异构的:一个核磁共振和分子动力学模拟研究
J Ropp1, C Lawrence, T C Farrar
1Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|August 17, 2001
概括
实验性NMR揭示了液态水中的异构旋转运动. 和氧-17的放松时间表明不同温度的分子重定向动态.
科学领域:
- 物理化学 物理化学
- 化学物理 化学物理
- 频谱学是一种光谱学.
背景情况:
- 核磁共振 (NMR) 光谱是一种用于探测分子动态的强大工具.
- 由于水在化学和生物过程中无处不在的作用,了解水的旋转动力学至关重要.
- 之前的研究已经提供了对水的结构和动态的见解,但精确的旋转相关时间仍然是一个活跃的研究领域.
研究的目的:
- 用NMR放松测量实验确定水分子的旋转相关时间.
- 为了研究水的旋转动态的温度依赖性.
- 为了评估水的旋转运动的异构性.
主要方法:
- 实验性核磁共振 (NMR) 测量 (T1) 和氧-17 (T1) 在丰富液体水中的放松时间.
- 从水的初始计算和实验化学转移测量中确定四极合常量和不对称性参数.
- 对放松数据的分析,以提取旋转相关时间.
主要成果:
- 在D2 ((16) O中OD键向量的旋转相关时间从275K的5.8ps降低到350K的0.86ps,从275K的5.8ps降低到0.86ps.
- 在D2(16) O中稀释D2(17) O的外平面向量的旋转相关时间从275K的4.4ps降低到350K的0.64ps.
- 实验结果表明,水分子的反旋运动是异构的.
结论:
- 这项研究提供了关于液态水中的异型旋转动态的实验证据.
- 核磁共振放松测量为特征分子重定向提供了一种可靠的方法.
- 在较低温度下实验数据和分子动力学模拟之间的差异突出了模拟模型的精细化领域.
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