Check the weight. According to official website, who inquired about the National Natural Science Foundation and learned that the purpose of duplicate checking in the application of the National Natural Science Foundation is to protect academic integrity, prevent academic misconduct and improve academic level. When applying for the National Natural Fund, you need to submit a declaration, and the contents in the declaration must be your own original research results, and there must be no plagiarism, plagiarism and other acts that violate academic norms. Therefore, the declaration should be checked to ensure that its contents are true and meet academic requirements.