中文摘要：

核磁共振（NMR）波谱技术是当今最有力的谱学工具之一,在化学、生物和医药等众多领域获得重要而广泛的应用.基于时空编码的快速采样方法自2002年Frydman小组提出后,大大增强了高维磁共振波谱的采样效率.在某一些应用体系中,存在若干个强度远超于其他谱峰的情况,很容易由于动态增益不足而检测不到某些较弱的谱峰,而往往这些较弱的谱峰包含着感兴趣的信息.且在实际的化学生物应用中,存在选择性感兴趣检测的情况,即只需要选择性地观察若干个具有标记作用的谱峰.由于时空编码技术借助于高速切换的双极性梯度来完成解码,因而无法选择性地检测若干个非连续的频点.为解决以上两个问题,该文提出一种选择编码的时空编码方法,即在序列中施加选择性脉冲,选择性破坏某些谱峰的编码过程,使之不能在解码期解码,从而简化谱图,实现选择性压制或者非连续频点的感兴趣检测.如果把选择性反转脉冲换为硬反转脉冲加选择性反转脉冲,则最终的谱图中只出现被选择性脉冲选中的谱峰.理论分析及相关的实验验证了这种方法的可行性和有效性.

英文摘要：

Nuclear Magnetic Resonance（NMR） is one of the most powerful analytical tools nowadays, with wide applications in the fields of chemistry, biology and medicine. The spatial encoding ultrafast method proposed by Frydman et al. in 2002 greatly enhanced the sampling efficiency of multi-dimensional NMR spectroscopy. One problem with the Frydman＇s method is that it is difficult to selectively detect multiple resonances at non-continuous discrete frequencies, due to the fast-switching bipolar gradients that are required for spatial encoding. In this study, we proposed a novel selective spatial encoding ultrafast method, aiming to solve two problems often encountered when utilizing the Frydman＇s method in practical chemical and biological applications. The first problem is to detect weak signals in the presence of strong signals with limited dynamic range; and the second problem is to detect the signals of interests（e.g., peaks from labeled nuclei） exclusively with the rest of resonances in the background unexcited. The proposed method utilized a selective pulse to destroy the encoding process selectively, such that selective suppression of strong peaks or excitation of non-continuous discrete frequency points of interest could be achieved. We also showed that only the spectral peak selected by the selective pulse would remain if the selective inverse pulse was replaced by a hard inverse pulse. The feasibility and validity of this method were demonstrated by both theoretical analyses and experiments.