波谱学杂志 ›› 1999, Vol. 16 ›› Issue (1): 13-20.

• 研究论文 • 上一篇    下一篇

脉冲梯度场增强的DQF-COSY实验t1噪声研究

林国兴1,2, 廖新丽1,2, 林东海1,2, 郑绍宽2, 陈忠1,2, 吴钦义1,2   

  1. 1 厦门大学化学系, 厦门 361005;
    2 厦门大学物理系, 厦门 361005
  • 收稿日期:1998-09-21 修回日期:1998-12-03 出版日期:1999-02-05 发布日期:2018-01-11
  • 作者简介:林国兴,男,1971年出生,博士研究生
  • 基金资助:
    This project was supported by the National Natural Science Foundation of China(19605004)and State Key Laboratory for Physical Chemistry of the Solid Surface

P-TYPE GRADIENT-ENHANCED DQF-COSY EXPERIMENTS SHOW LOWER t1 NOISE THAN N-TYPE

Lin Guoxing1,2, Liao Xinli1,2, Lin Donghai1,2, Zheng Shaokuan2, Chen Zhong1,2, Wu Qinyi1,2   

  1. Department of Chemistry, Xiamen University, Xiamen 361005
  • Received:1998-09-21 Revised:1998-12-03 Online:1999-02-05 Published:2018-01-11
  • Supported by:
    This project was supported by the National Natural Science Foundation of China(19605004)and State Key Laboratory for Physical Chemistry of the Solid Surface

摘要: 脉冲相位的不稳定性是导致二维谱中的t1噪声的原因之一.本文从理论上和实验上对脉冲相位不稳定性所引起的t1噪声进行了研究.从角动量算符Ix,Iy和Iz推导中发现,由于磁化矢量在P型和N型DQF-COSY实验的脉冲梯度场中进动方向的内在差异,一部分脉冲相位误差在P型DQF-COSY实验会被重聚掉,在N型DQF-COSY实验中却会被加重.因此P型DQF-COSY实验的t1噪声比N型小.理论推导还得到t1噪声在P型和N型中的理论比值为√3:√11.以上理论结果得到我们实验结果的支持.

关键词: NMR, DQF-COSY, 脉冲梯度场, t1噪声, 积算符

Abstract: t1 noise, stemming from the instabilities of pulse phases in 2D spectroscopy, has been investigated theoretically as well as experimentally. Based on the angular momentum operator Ix,Iy,Iz formalism, our deductions show that the different precessing directions of the magnetization between P-type and N-type gradient enhanced DQF-COSY experiments result in that P-type gradient enhanced DQF-COSY experiments refocus the phase errors of pulses, while N-type gradient enhanced DQF-COSY experiments strengthen the effect of the phase errors of pulses. Therefore, t1 noise in P-type gradient enhanced DQF-COSY experiments is lower than that in N-type. In addition, the theoretical ratio of P-type to N-type is √3:√11, which is supported by our experimental results.

Key words: NMR, DQF-COSY, PFG, Product operator, t1 noise