The publications of SCI four zones are often questioned by the authors because they are the last zone in SCI. The division of SCI is mainly based on the impact factors of journals, which is also the reason why journals in four fields of SCI are often questioned by some authors. However, the SCI papers in the four districts certainly have some gold content, but they are slightly inferior to the periodicals in the first, second and third districts.

SCI generally refers to scientific citation index, which is an internationally recognized main retrieval tool for scientific statistics and scientific evaluation. Its journals adopt a variety of rigorous and scientific quantitative and qualitative screening, and include the most important and influential research achievements in the world. The research achievements of SCI represent the highest level of basic discipline research in the world. For colleagues engaged in scientific research, an academic paper was successfully published by SCI, which means that the author entered the international academic frontier in this field.