Randall E W, Samoilenko A A, Fu R
Department of Chemistry, Queen Mary and Westfield College, London, UK.
Solid State Nucl Magn Reson. 1999 Sep;14(3-4):173-9. doi: 10.1016/s0926-2040(99)00022-3.
We have observed Hahn-echoes resulting from Powles-Mansfield pulse-sequences for a variety of nitrogen containing solids which exhibit a range of 14N electric quadrupole coupling constants (Cq) from 0 to 4.9 MHz. Long echo-decays were frequently obtained which allowed the collection of many echoes in one echo-train, so that the method of Long Echo-Train Summation (LETS), could be used to accumulate signal. A one-dimensional STRAFI-profile is shown for solid ammonium nitrate. The spatial resolution is discussed as a function of Cq.
我们已经观察到，对于各种含氮固体，由鲍尔斯 - 曼斯菲尔德脉冲序列产生的哈恩回波，这些固体呈现出范围从0到4.9兆赫兹的一系列14N电四极耦合常数（Cq）。经常获得长回波衰减，这使得在一个回波串中可以采集许多回波，从而可以使用长回波串求和（LETS）方法来累积信号。给出了固体硝酸铵的一维STRAFI分布图。讨论了空间分辨率与Cq的函数关系。
