振动引起的不稳定磁场对核磁共振谱图的影响  

Influence of Unstable Magnetic Field on NMR Spectra Due to External Vibration Interference

作　　者：林雁勤[1] 陈希[1] 林涛[1] 柯恩锋[1] 陈忠[1] 

机构地区：[1]厦门大学物理学系,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2006年第3期328-332,共5页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金(10375049);教育部优秀青年教师资助计划资助

摘　　要：在核磁共振实验中,地基振动等外界干扰会引起磁场不稳定,从而影响高分辨核磁谱图的质量.为探讨振动对谱图的影响,本文将外界振动引起的不稳定磁场作为微扰项,通过Bloch方程从理论上分析了其产生振动干扰峰的机理和振动干扰峰在谱图中的分布规律,并利用计算机模拟了几种典型的外界振动产生的干扰峰在谱图上的分布,通过差谱实验揭示了外界振动对谱图的影响.研究结果表明:外界振动会使谱图的线形变差、线宽增大和相位扰乱,从而降低谱图的分辨率.实验结果与理论预测和模拟结果相吻合.In nuclear magnetic resonance （NMR） experiments, external vibration may result in unstable field which reduces the quality of high-resolution spectra. In this paper, a physical model of the unstable field due to external vibration was introduced to Bloch equations to analyze the formation mechanism of vibrated-caused artifacts and their distribution. Computer simulations were employed to study several typical external vibration interferences. Difference spectroscopy was utilized to characterize vibrationcaused artifact peaks. It shows that external vibration will result in bad lineshape, large linewidth, and dispersive effect, thus reduce the spectral resolution. Experiment results are consistent with the theoretical predictions and simulated results.

关 键 词：核磁共振 振动 不稳定场 计算机模拟 差谱 

分 类 号：O482[理学—固体物理]