Theory of intramolecular spin relaxation by translational diffusion in locally ordered fluids
Theory of intramolecular spin relaxation by translational diffusion in locally ordered fluids
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局部有序流体中平移扩散的分子内自旋弛豫理论
DOI：
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发表时间：
1984
期刊：
影响因子：
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通讯作者：
B. Halle
中科院分区：
文献类型：
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作者：
B. Halle
在局部有序流体中，例如大分子溶液、粘土和溶致液晶，可以通过流体分子的平移扩散，通过调制残余分子内自旋晶格耦合张量的大小和方向来诱导核自旋弛豫，该张量仅由界面附近的局部分子运动部分平均。发展了由平面界面界定的局部有序流体中的自旋弛豫理论，特别强调平移扩散的影响。该理论基于连续扩散模型 (CDM)，与普遍采用的离散交换模型 (DEM) 相比，该模型以自洽的方式处理均衡和时间相关的分布函数。异质系统中平移扩散的一个显着特征是与先前访问过的界面区域的大量重新相遇。事实证明，这些扩散的重逢是 CDM 理论所固有的，可能会导致放松……
In locally ordered fluids, such as macromolecular solutions, clays and lyotropic liquid crystals, nuclear spin relaxation can be induced by modulation, through translational diffusion of the fluid molecules, of the magnitude and orientation of the residual intramolecular spin-lattice coupling tensor, which is only partially averaged by local molecular motions near an interface. A theory of spin relaxation in locally ordered fluids bounded by planar interfaces is developed, with special emphasis on effects of translational diffusion. The theory is based on a continuous diffusion model (CDM) which, in contrast to the commonly adopted discrete exchange model (DEM), treats equilibrium and time-dependent distribution functions in a self-consistent way. A striking feature of translational diffusion in heterogeneous systems is the abundance of reencounters with previously visited interfacial regions. It is demonstrated that these diffusional reencounters, which are inherent in the CDM theory, may lead to a relax...