This paper is divided into six levels, which are explained as follows:

1, Class T: Special periodical papers, which refer to papers published in Science and Nature.

2. Class A: authoritative core publications, which refer to papers collected by internationally accepted retrieval systems such as SCIE, EI, ISTP, SSCI and A&HCI.

3. Class B: Important core journal papers refer to papers published in foreign core journals.

4. Class C: general core journal papers.

5. Class D: Papers published in general public journals refer to papers published in domestic public journals.

6. Class E: Papers published in restricted journals refer to papers published in domestic journals whose distribution is restricted.

The purpose and significance of graduation thesis

Purpose:

1, cultivate students' scientific research ability.

2, strengthen the comprehensive application of knowledge, theory and skills to solve practical problems training.

3. Generally, students' academic level in university is examined.

Meaning:

1. Writing graduation thesis is an important measure to test students' academic performance in school and an important link to improve teaching quality.

2. By writing graduation thesis, improving the writing level is the need of the "four modernizations" construction of cadres.

3. Improving college students' writing level is the need of socialist material civilization and spiritual civilization construction.