射频场照射下扩展的Solomon方程及射频场的照射对异核体系弛豫速率与NOE的影响  

The extended Solomon equations with RF irradiation and the effects of RF irradiation on relaxation rates and NOE

作　　者：许峰[1] 黄永仁[2] 

机构地区：[1]安徽理工大学数理系,淮南232001 [2]教育部光谱学与波谱学重点实验室,华东师范大学物理系,上海200062

出　　处：《物理学报》2002年第6期1371-1376,共6页Acta Physica Sinica

基　　金：安徽省教育厅自然科学基金 (批准号 :2 0 0 1KJ2 2 5ZC)资助的课题~~

摘　　要：根据WBR理论 ,采用“改进的矩阵计算方法” ,推导出了射频场照射下扩展的Solomon方程 ,并据此研究了射频场的照射对异核体系各种弛豫速率与NOE的影响 ,得出了如下结论 :1)给出的方程比Boulat和Bodenhausen的方程更准确、更具普遍性 ,能够具体描述射频场对各种弛豫速率与NOE的影响 .2 )射频场的照射对纵向与横向弛豫速率的影响甚微 ,可以忽略 ,而交叉弛豫速率在射频场的照射下则有一定程度的降低 .3)射频场的照射将使NOE变弱 ,且射频场越强 ,NOE越弱 .It is known that the Solomon equations can't be used to describe cross relaxation and steady-state NOE in the presence of the RF radiation. In order to lift this contradiction, Boulat and Bodenhausen presented an extension of the Solomon equations. This paper, according to the WBR theory and using 'improved matrix computation method', deduces the extended Solomon equations with RF irradiation. By means of these equations, the effects of RF irradiation on relaxation rates and NOE of heteronuclear system are discussed and studied, and the following conclusions are presented: (1) The extended Solomon equations with RF irradiation presented by us are more universal and accurate than those of Boulat and Bodenhausen, and they can exactly describe the effects of RF irradiation on various relaxation rates. (2) The effects of RF radiation on longitudinal and transverse relaxation rates are negligible, while the RF radiation depresses cross-relaxation rate to some extent. (3) The RF radiation makes NOE decline. The more RF radiation is strong, the more NOE is weak.

关 键 词：射频场照射 核磁共振 Solomon方程 射频场 异核体系 弛豫速率 NOE 

分 类 号：O482.531[理学—固体物理]