substituting group meaning in English

取代基

The nonlinear properties of the type compound of chalcone have been studied using finite field ( ff ) / pm3 method . the influence of the molecular structures , the type of substituting group and its sites on organic conjugated molecular electronic and nonlinear properties have also been studied for different substituting group and its sites . the results proved that the substiuting group noucd improve obviously the nonlinear properties of the system
利用有限场ff pm3方法讨论了查尔酮类化合物的非线性光学性质，针对不同取代基和取代位置系统分析了分子结构、取代基的类型、取代位置对共轭有机分子电子性质及非线性光学性质的影响结果表明，取代基的引入可明显改善体系的非线性光学性质