There are two kinds of SCI journals. One is JCR, that is, Thomson Reuters. * * There are four regions, namely Q 1, Q2, Q3 and Q4. The top 25% (including 25%) journals are divided into Q 1 region, and the top 25% ~ 50% (including 50%) journals are divided into Q2 region. The other is the Chinese Academy of Sciences, which also has four districts, 1 -4, which is different from JCR in title. The first 5% is 1, 6% ~ 20% is 2, 2 1% ~ 50% is 3, and the rest is 4.

The biggest difference between these two divisions is that the interval standard of impact factors is different. There are fewer periodicals in Chinese Academy of Sciences 1 area than in JCRQ 1 area, and the quality is higher. Both partitions can be selected. See the requirements of the author's unit for specific division criteria. At present, China Academy of Sciences is widely used in domestic universities and scientific research units, and some units have divided periodicals according to actual needs, so