Sci journals are divided into four regions, and two zoning standards are adopted. Let me talk about the division of the Chinese Academy of Sciences. The top 5% is 1, 6%-20% is 2, 2 1%-50% is 3, and the rest is 4. In addition, the influence of JCR on journals is attributed to Q 1 (the first 25%), Q2(25%-50%), Q3(50%-75%) and Q4 (the last 25%).
The full name of SCI is Scientific Citation Index, which means scientific citation index. It is a citation database founded by EugeneGarfield of institute for scientific information (ISI) in Philadelphia, USA on 1957. SCI (Science Citation Index), EI (Engineering Index) and ISTP (Science and Technology Conference Index) are three world-famous retrieval systems for scientific documents, which are internationally recognized as the main retrieval tools for scientific statistics and scientific evaluation.