The meaning of core journals and source journals
1 core journals
Refers to a periodical that publishes a lot of information related to a certain discipline (or specialty) with a high level, which can reflect the latest achievements and frontier trends of the discipline and is particularly concerned by readers of the specialty. This refers to the Chinese core journals listed in the general survey, published in 1992, reprinted in 1996, and the third edition in 2000.
Two sources of periodicals
Refers to those journals that provide source documents when compiling retrieval tools (databases). The source journals mentioned here refer to the statistical source journals of scientific papers in China, which are evaluated and selected by ISTIC according to bibliometrics methods and can objectively reflect and display the latest scientific research achievements and cutting-edge level. ISTIC started from 1987 to make a statistical analysis on the number of papers published by China scientific and technical personnel at home and abroad and their citation. A database of scientific papers and citations in China was established by using statistical data. Based on the database of scientific papers and citations, CJCR has selected more than 1300 Chinese and English scientific and technological documents published in Chinese mainland from the fields of mathematics, information and system science, physics, mechanics, chemistry, astronomy, earth science, biology, medicine and health, agricultural science, industrial technology, electronics and communication, computing technology, transportation, aerospace and environmental science.
3 Selection criteria of core journals and source journals
1943 Samuel Clement Bradford, a famous British bibliometrist, discovered and put forward the distribution law of documents (academic papers) in publications: that is, a large number of academic papers on a specific subject are concentrated in a few publications. The rest of the papers are scattered in a large number of publications. Someone has studied the distribution of secondary documents (abstracts, titles, indexes) and reached the same conclusion. It shows that there are centralized and decentralized phenomena in the process of generation, information processing (secondary literature) and use (borrowing and quoting) of subject literature, which is the basis for determining core journals [2]. There is no obvious difference between core area and non-core area. The selection criteria of census journals are: cumulative published articles account for 30% ~ 50% of the total published articles, cumulative abstracts account for 50% ~ 70% of the total abstracts, and cumulative cited articles account for 70% ~ 80% of the total cited articles.
The selection criteria of source journals are 17, namely: (1) total cited frequency; (2) Influencing factors; (3) annual indicators; (4) Self-citation rate; (5) he cited rate; (6) price index; (7) cited half-life; (8) cited half-life; (9) Aging coefficient; (10) Source Doc amount; (1 1) Number of citations; (12) average citation rate; (13) average number of authors; (14) area allocation number; (15) Number of institutions; (16) international paper ratio; (17) Fund-paper ratio. The impact factor refers to the ratio of the total number of citations of papers published in the first two years of a journal to the total number of papers published in the first two years of the journal. Generally speaking, the greater the impact factor of a journal, the greater its academic influence and role.