1, level 1 T.

Specialized periodical papers refer to papers published in Science and Nature.

2. Grade II A..

Authoritative core journals refer to internationally accepted SCIE, EI, ISTP, SSCI, A &；; Papers included in the retrieval system by HCI (subject to the retrieval by China Institute of Science and Technology Information), or authoritative articles on the same topic published in domestic Chinese core journals, excluding other report abstracts.

3. Class B, level 3. Important core journals refer to 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 similar disciplines in China.

4. level 4, class C.

For general core journals, refer to "Overview of National Chinese Core Journals"? Papers published by Peking University Library, 2004 edition.

5. Category 5 D. Papers published in general public journals refer to papers published in domestic public journals (journal numbers "CN" and "ISSN" with postal codes).

6. grade e, grade six.

Papers published in restricted public publications refer to papers published in domestic publications that are publicly released but restricted (only periodical number, no mailing code).

The purpose and significance of graduation thesis;

1, comprehensive application of knowledge.

The graduation thesis requires students to comprehensively use all kinds of knowledge and skills they have learned in this major, and deepen their understanding and mastery of what they have learned by independently choosing research topics, determining research methods and analyzing research results.

2. Improve research ability.

Graduation thesis requires students to have strong ability to think and analyze problems independently, and accumulate scientific research experience and skills by consulting literature, designing experiments and analyzing data, so as to improve students' research ability and innovation ability.

3. Promote academic exchanges.

Graduation thesis is the communication and exchange between students and tutors, and also the communication and interaction between students and peers. Students can communicate with their peers and share research results by attending academic conferences and publishing papers, thus promoting academic exchanges and cooperation.

4. Lay a foundation for future career development.

Graduation thesis is an important symbol for students to complete undergraduate education, and it is also the basis for students' future career development. Through the research of graduation thesis, students can accumulate experience and knowledge in related fields and lay a solid foundation for future work and research.