Core journals refer to academic journals with high influence and authority in a certain discipline. These journals usually require high quality papers, so if the master's thesis is published in these journals, it needs to be innovative and academic. The following are some core journals that accept master's single papers:

1. Journal of Graduate School of Chinese Academy of Social Sciences: This journal mainly publishes research results in the social sciences, including economics, law, education, literature, history, etc.

2. Journal of Peking University (Philosophy and Social Sciences Edition): This journal mainly publishes research results in the field of philosophy and social sciences, including philosophy, politics, sociology, law and economics.

3. Journal of Nanjing University (Philosophy, Humanities and Social Sciences Edition): This journal mainly publishes research results in the fields of philosophy, humanities and social sciences, including philosophy, history, literature, art and economics.

4. Journal of Wuhan University (Philosophy and Social Sciences Edition): This journal mainly publishes research results in philosophy and social sciences such as philosophy, politics, sociology, law and economics.

5. Journal of Jilin University (Philosophy and Social Sciences Edition): This journal mainly publishes research results in philosophy and social sciences such as philosophy, politics, sociology, law and economics.