Core journals are the main journals of a certain discipline. Generally speaking, it refers to a professional periodical with a large amount of professional information and high quality, which can represent the development level of professional disciplines and is valued by readers of this discipline. Relevant experts have found that the actual distribution of literature information sources has the effect of core journals, that is, a large number of scientific papers in a professional world are concentrated in a few scientific journals. This phenomenon can be seen in many fields, for example, from the study of the world literature of physics in France's Signal Bulletin, it is found that 90% abstract items are only taken from 30% of all journals, and chemical abstracts can be extracted from 9% of all journals to 75% of all abstract items.
Therefore, in the era of literature information surge, the effect of core journals has been widely concerned by people. There are many ways to determine the core journals. Generally, our country comprehensively determines according to the following principles: (1) journals with a large number of articles (that is, the number of documents published in this discipline); (2) Journals with a large amount of secondary literature excerpts; (3) Periodicals frequently cited by readers.