波谱学杂志 ›› 1996, Vol. 13 ›› Issue (6): 547-555.

• 研究论文 • 上一篇    下一篇

脉冲梯度场NMR实验中的弛豫和辐射阻尼效应

陈金鸿, 毛希安   

  1. 中国科学院武汉物理所波谱与原子分子物理国家重点实验室, 武汉 430071
  • 收稿日期:1996-04-16 修回日期:1996-06-06 出版日期:1996-12-05 发布日期:2018-01-17
  • 基金资助:
    国家自然科学基金资助项目

RELAXATION AND RADIATION DAMPING EFFECTS IN NMR EXPERIMENES OF PULSED FIELD GRADIENTS

Chen Jinhong, Mao Xi'an   

  1. State Key Laboratory of Magnetic, Resonance and Atomic and Molecular Physics, Wuhan Institute of Physcis, The Chinese Academy of Sciences, Wuhan 430071
  • Received:1996-04-16 Revised:1996-06-06 Online:1996-12-05 Published:2018-01-17

摘要: 使用梯度脉冲压制水峰已广泛地应用于生物样品的NMR实验,一个选择性90°脉冲接一个纵向的散相梯度脉冲破预期能得到好的去水峰效果,然而基于下面的三方面的原因,梯度脉冲去水峰的效果受到了限制,其一是梯度散相的动力学过程表明总磁化强度的衰减是需要时间的,其二是纵向弛豫T1机制在梯度脉冲作用过程中不可避免,其三是辐射阻尼效应力图将磁化强度推向z方向.在本文中我们定量地分析了这三种机制在压水峰过程中的作用.

关键词: 梯度脉冲, 散相动力学, 纵向弛豫, 辐射阻尼

Abstract: Suppression of water peak with pulsed field gradient has been widely used in NMR experiments of biological samples. p selective 90° pulse followed by a z gradient pulse is expected to result in a good suppression.In this paper,the spin dynamics in the presence of gradient field is quantitatively analyzed,and the longitudinal relaxation and the radiation damping effects during the gradient pulsing are discussed.It is shown that high strength and short duration of the gradient are a choice for better water signal suppression.

Key words: Pulsed gradient, Phase randomization dynamics, Longitudinal relaxation, Radiation damping