U.S.-China Cooperative Research (Chemistry): Dynamic Nuclear Polarization in Carbonaceous Solids

这是一个为期两年的合作项目，加里马西埃尔 科罗拉多州立大学的叶朝辉和武汉大学的 中国科学院物理研究所。 是 由美国国家科学基金会和中国科学院联合主办。 研究将侧重于持续发展和 应用动态核极化（DNP），一个强大的 电子自旋/核自旋双共振技术， 增强核磁共振中的核自旋极化 对含有这两种物质的材料进行共振（NMR）实验 磁核和未成对电子。 DNP特别是 在中国和美国煤的特性方面很重要 diamond.like在中国和美国制备的碳膜。 laboratories. 对于煤炭研究来说， 美国和某些国家测量的磁共振特性 中国煤炭将被深入研究， 模型将探讨解释这两种类型的煤 这些具体的差异。 在金刚石薄膜的研究中， 将阐明“缺陷”结构的性质， 与薄膜性质和制备方法有关。 的 1.9 T DNP光谱仪中使用的异常场强 武汉物理研究所将提供一个很好的机会， 为了阐明DNP现象的基本细节， 这些样品（通过DNP性质的场依赖性） 并为DNP建立最佳磁场 典型的碳质固体的研究。

This is a two year collaborative project between Gary Maciel of Colorado State University and Ye Chaohui of the Wuhan Institute of Physics, Chinese Academy of Sciences. It is sponsored jointly by NSF and the Chinese Academy of Sciences. Research will focus on the continued development and application of dynamic nuclear polarization (DNP), a powerful electron.spin/nuclear.spin double.resonance technique that enhances the nuclear spin polarization in Nuclear Magnetic Resonance (NMR) experiments on materials containing both magnetic nuclei and unpaired electrons. DNP is especially important in the characterization of Chinese and U.S. coals and diamond.like carbon films prepared in Chinese and U.S. laboratories. For the coal studies, the striking differences between magnetic resonance properties measured for U.S. and certain Chinese coals will be examined in depth, and structural models will be explored for explaining both types of coals and these specific differences. In the diamond film studies, the nature of "defect" structures will be elucidated and related to film properties and preparation methods. The unusual field strength used in the 1.9 T DNP spectrometer in the Wuhan Institute of Physics will provide a good opportunity for elucidating fundamental details of the DNP phenomenon in these samples (via the field dependence of DNP properties) and for establishing the optimum magnetic field for DNP studies of typical carbonaceous solids.