Different collections, different publishing difficulties and so on.

The scope of 1, EI and SCI periodicals is different: EI periodicals are biased towards engineering and SCI towards science. Engineering Index (EI) is the oldest large-scale comprehensive retrieval tool, which was founded by the American Federation of Engineers in 1884. EI enjoys a high reputation in the academic, engineering and information circles all over the world, and it is recognized as an important retrieval tool by the scientific and technological circles. SCI (ScienceCitationIndex) is a citation database founded by EugeneGarfield of institute for scientific information (ISI) in Philadelphia, USA on 1957. At the same time, SCI (Science Citation Index), EI (Engineering Index) and ISTP (Science Conference Record 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. EI journals and SCI journals are included in these two indexes, which are both influential journals in academic circles.

2. The publishing difficulty of EI journals and SCI journals is different: generally speaking, EI journals and SCI journals are internationally renowned and recognized. However, from the point of view of publication, SCI may be a little more difficult. SCI is a comprehensive citation database, covering a wide range of disciplines. Moreover, SCI itself is difficult to submit and requires a long space. Generally, the length of SCI papers is about 20-40 pages, and the review period of SCI papers is relatively long, generally 2-4 months. EI mainly publishes academic papers in the field of engineering technology, SCI is mainly academic journals, EI has academic journals and conferences, EI's articles tend to be applied in engineering, and some Chinese journals are friendly to researchers in China. It can be seen that SCI journals are more difficult to publish than EI journals. If students are given an order, it will be like this. EI journal > EI conference.