Sci selection criteria are as follows:

Publication time limit is the most important criterion for ISI to select periodicals. Every periodical should be published at the time specified by ISI. ISI editors reading at least three periodicals that often exceed the publication time limit are not within ISI's choice.

International editorial norms: conforming to international editorial norms is also an important publication selection standard of ISI. Standardization can optimize the retrieval of each document, such as the title information of the paper, the complete description of the title and abstract of the paper, the complete bibliographic information of all references, the detailed address of each author, English titles, abstracts and keywords.

The information of peer review process is the index of periodical selection and represents the academic quality of periodical research. Another criterion representing academic level is whether or not to accept fund support.

Editor's content: The professional trend of academic research is an important criterion for selecting periodicals. The core of general scientific literature only accounts for a relatively small part of journal content. With the development of science and technology, new research fields and interdisciplinary subjects can enrich ISI database, which has also been selected as a periodical source.

Internationalization of periodicals: the internationality of the geographical distance between the author and the editorial department shows the basic conditions for a periodical to become an international periodical. ISI selects some representative journals whose contributors cooperate across regions, borders and international cooperation. The academic papers of multi-nationality authors highly represent the hot spots in the current research field, so the hit rate is high when choosing journals.