Long-lived Nuclear Spin Order - Theory and Applications
Long-lived Nuclear Spin Order - Theory and Applications
复制标题
长寿命核自旋有序 - 理论与应用
DOI：
10.1039/9781788019972-00302
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Torres A
中科院分区：
文献类型：
--
作者：
Torres A
扩散核磁共振是一种非常有用的技术，它具有广泛的应用，从研究溶液中的分子性质、动力学和过程，如结合到探测受限的几何形状，如微孔(如生物细胞、沸石)和溶液环境中的其他结构(如超分子聚集体)。1、2测量的基础是将由射频(RF)脉冲、磁场梯度脉冲和延迟组成的基于回波的脉冲序列施加到核自旋并获取回波信号。该序列的构造使得所测量的回波信号的衰减与在脉冲序列A中的扩散延迟期间分子的自(或平移)扩散(即，均方位移)以及扩散测量梯度脉冲的幅度和持续时间相关。A的最大可用值取决于能够获得具有足够信号的回波信号--音调--而这最终取决于序列中发生的自旋弛豫量。几乎所有的核磁共振扩散测量方法都基于两个前体脉冲序列中的一个：脉冲
Diffusion NMR is a very useful technique that has a variety of applications from studying molecular properties, dynamics and processes in solution such as binding to probing restricted geometries such as microscopic pores (eg, biological cells, zeolites) and other structures in the solution environment (eg, supramolecular aggregates). 1, 2 The measurement is based on applying an echo-based pulse sequence consisting of radio frequency (RF) pulses, magnetic field gradient pulses and delays to the nuclear spins and acquiring an echo signal. The sequence is constructed so that the measured attenuation of the echo signal is related to the self-(or translational) diffusion of the molecule (ie, the mean square displacement) during the diffusion delay in the pulse sequence, A, and the amplitude and duration of the diffusion-measuring gradient pulses. The largest usable value of A is determined by being able to acquire an echo signal with sufficient signal-tonoise–and this is ultimately determined by the amount of spin relaxation that has occurred during the sequence. Almost all NMR diffusion measuring methods are based on one of two progenitor pulse sequences: the pulsed