I. Class T (level I)
Special periodical papers: Papers published in Science and Nature are special periodical papers. Two. Class a (level 2)
Authoritative core journal papers: SCIE, EI, ISTP, SSCI and A &；; Papers included in the HCI retrieval system (subject to the retrieval by China Institute of Science and Technology Information) or papers on the same topic published by authoritative Chinese core journals in China do not contain reportable abstracts, abstracts, news, etc.
Three. Class b (level 3)
Important core journal papers: papers published in foreign core journals (see Handbook of Foreign Science and Technology Core Journals) or papers with important influence published in Chinese core journals of domestic classmates.
Four. Class C (Level 4)
General core journal papers: papers published in the magazine "Overview of National Chinese Core Journals". The Catalogue of Chinese Core Journals was jointly published by China Knowledge Network, China Academic Journals Network and Peking University Library Journal Work Research Association.
Verb (abbreviation of verb) Class D (level 5)
Papers published in general public journals: papers published in domestic public journals with double serial numbers (journal numbers "CN" and "ISSN" with postal codes).
6. Grade E (Grade 6)
Papers published in restricted public publications: refers to papers published in publications that are publicly released in China but have restricted distribution (only periodical number, no mailing code).