The identification of Chinese core periodicals is determined by Peking University Library. Periodicals are classified by content and divided into volumes and issues by time. Volume is a time classification over a period. The "number of periods" here is the number of periods issued in chronological order in 1 year; The "volume" is the chronological number of this publication, which has been accumulated year by year since the year of its publication.

The criteria for determining core journals can be summarized as follows:

1, the authority of the organizer,

2. The authority of the author of the article,

3. Citation rate of articles and half-life of documents (generally, the half-life of scientific and technological documents is short, while that of social science documents is long). To put it simply, core journals are the most important core journals, which are tracked and evaluated by academic circles through a set of scientific methods and classified and graded according to the theory of information science.