基于化学位移的结构编码及其应用

采用系统编码以一原子为中心逐层扩展的思想，在形式上加以改进，同时用核磁共振中最重要的参数一化学位移值表征碳原子所处的状态，实现了结构的数值化，使化学结构更易被计算机存储和处理，也使判断两结构是否全同(两图同构)的难题简化为比较两者化学位移值之和CSS(Chemical Shift Sum)是否相等的简单问题。进而针对两类子结构检索各自的特点提出了新的基于广度优先的匹配算法，此算法以特征原子作为初始匹配点能大大减少匹配的盲目性。C^13-NMR是一个已积累了大量知识和规律的领域，碳化学位移值又是碳原子核周围电子云分布情况的直接反映，从这些已有的知识和规律出发正确地获取所需信息将会对计算机辅助有机合成路线设计和分子设计等诸多方面起到积极的推进作用。

A new structure code based on chemical shift and it's application

A new code based on chemical shift was proposed,which replaced the atom and bond type with the chemical shift of carbonatom.Thus the chemical structure can be represented by numbers.Chemical shift is highly sensitive to atom's surrounding enviroment,one structure's CSS(chemical shift sum)will not equal to another's unless they are same,so CSS can be used to judge if two structuresare same uniquely.New arithmetics were advanced discriminately according to the character of two kinds of sub-structure searchingwhich can decrease the blindness in the process of searching greatly.Since chemical shift is determined by the distribution of carbonicelectron cloud,it's advantaged to use this information to predict compound's reactive site which is important in many fields.