NMR论文：NMR 模糊识别 化学位移 最大隶属原则.docVIP

NMR论文：NMR 模糊识别 化学位移 最大隶属原则 【中文摘要】自从珀塞尔和布洛赫发现核磁共振现象后,激发了人们对核磁共振研究的兴趣,核磁共振技术得到了迅速发展,广泛的应用于生活中的各个领域,如物理、化学、材料科学、生命科学和医学等领域。目前,核磁共振波谱分析技术成为研究物质分子结构和鉴别未知物种类的重要手段,它的主要任务之一就是根据核磁共振波谱中与峰位相应的化学位移对待分析样品中的未知化合物进行定性判别分析。由于未知谱图的复杂多样性,用肉眼鉴别未知物种类不仅速度慢,而且很困难,为了更加方便快速的对待分析的核磁共振谱进行定性分析,本文提出了一种基于最大隶属原则的核磁共振(NMR)波谱模糊识别方法。该方法首先提出了关于待分析核磁共振波谱的模糊集概念,并给出了相应的隶属函数;其次,为了避免假峰的干扰,有效地对实验所得波谱进行识别分析,则通过Matlab编程,使原始谱数据进行小波变换,特征提取,重构等得到比较满意的谱数据;最后,建立标准谱数据库以及相应的模糊识别算法,根据最大隶属原则,使用计算机计算标准谱在待分析谱中的隶属度,根据统计涨落原理给定阈值的范围,从而定性的分析未知谱。这样通过建立标准谱数据库以及相应的模糊识别算法就实现了未知待测核磁共振波谱的快速自动定性分析。本文中,对苯酚、邻苯二酚、间苯二酚及对苯二酚4种化合物的11种混合物样品的核磁共振1H谱进行了定性分析。结果表明,在粗略找峰和隶属度阈值在0.45到0.85之间较大范围内取值的情况下,方法均给出了准确的识别结果。 【英文摘要】When the Purcell and the Bloch found the phenomenon of nuclear magnetic resonance (NMR), it inspires people to research the NMR. The technology of NMR has developed rapidly and widely in every field of life, such as physics, chemistry, material science, life sciences and medicine, etc. At present, NMR spectrum analysis technology becomes the important means which research material molecular structure and identify unknown species. It is one of the main tasks that qualitative discriminate and analysis the unknown chemical compound according to the NMR spectrum corresponding with the peak positions in the chemical displacement.Due to unknown spectrums of the complex diversity, it is not only very slow and difficult to identify an unknown species directly with the eyes. A method of fuzzy recognition for NMR spectra based on maximum principle of membership was brought forward, in order to better simply and rapidly analysis the NMR spectra of the unknown. Firstly, the concept of fuzzy set for NMR spectra to be analyzed was introduced, and membership function was given. Secondly, it avoid false peaks of the interference by making program of the Matlab, making the original spectrum data wavelet transform , feature extraction and reconstructing etc. Finally, Membership function was given based on maximum principle of membership by e