【摘要】 尽管已有大量化学反应数据可供使用 ,但化学家仍常常感到很难便捷地从中得到所需的信息 .这主要是由于反应数据库基于结构的检索方法与化学家解决问题的方法相去甚远 .为解决这一问题而发展了一种通过对反应进行二级分类得到精细描述反应知识的层次模型的方法 .第一次分类时不同的同类反应都在由一组普适性好的称作反应结构一级描述符构成的空间中进行 .在第一次分类结果的基础上 ,得到每一类反应的公共结构特征作为第二次分类的结构描述符 ,利用它们进行更精细的分类 ,即可从原始反应数据中得到所需的基核反应 .由特定反应、基核反应和基型反应就可将反应知识更合理地组织在同类反应知识库中 ,使它们得到更好的利用 .更多还原

【Abstract】 Although a huge amount of reaction data are available, chemists still feel inconvenient to find relevant information from these data. The main reason is that the current reaction databases are based on substructure searching which is an approach quite different from that chemists often use. This problem is solved by a novel approach, which acquires reaction knowledge finely described in a layer model by executing twice classification on the reactions. In the first layer classification the reactions are classified in a hyperspace created based on a set of widely applicable reaction descriptors named first order reaction descriptors. On the basis of the results of the first classification, we can extract the common structural characteristics that are used as the reaction descriptors in the second layer classification and lead to a finer classification. Thus, we can obtain the reaction cores from the second finer classification of the reactions. By integration of specific reactions, reaction cores and reaction types, the reaction knowledge can be more rationally organized in a generic reaction knowledge base with better utilization.更多还原