It is a supplementary explanation to the main title. In order to clarify the specific theme, some papers will adopt a combination of positive and negative titles, and the negative title is a supplementary explanation to the main title. The word thesis, which is common in classical literature, refers to speaking or exchanging ideas. Papers are often used to refer to articles that carry out research in various academic fields and describe academic research results, which are referred to as papers for short. It is not only a means to discuss problems in academic research, but also a tool to describe academic research achievements in academic exchanges, including academic papers, graduation papers, degree papers, scientific papers, achievement papers and so on. A paper generally consists of name, author, abstract, key words, text, references and appendix. According to the nature of content and research methods, the paper can be divided into theoretical papers, experimental papers, descriptive papers and design papers.