为从期刊文献的学科属性实现族性检索并为文章的分类统计创造条件,凡具有文献标识码的文章均应标识分类号。经国家新闻出版总署批准,参照执行的CAJ-CD规范中的中图分类号采用《中国图书馆分类法》(第四版)进行分类。文章一般标识1个分类号,多个主题的文章可标识2个或3个分类号; In order to realize the ethnic retrieval from the subject attribute of periodical literature and to create the conditions for the classification and statistics of articles, all articles with document identification code shall be identified with the classification number. Approved by the State Press and Publication Administration, the reference to the implementation of the CAJ-CD specification in the class number using “Chinese Library Classification” (fourth edition) for classification. Articles generally identify a classification number, articles on multiple topics identify two or three classification numbers;