2. Abstract is a brief statement of the content of the paper. It is an independent and complete essay, usually written in the third person tone, without comments or supplementary explanations. Should be independent and self-sufficient, that is, you can get the necessary information without reading the full text of the paper. Generally, the purpose, methods, results and conclusions of the research work should be explained, with emphasis on the results and conclusions. Generally, the number of Chinese abstracts is 300~600 words, while the number of substantive English abstracts is about 300 words, which can be slightly more if there is special need. As far as possible, unknown and common figures, tables, chemical structures, symbols and terms should be avoided. 3. Keywords keywords (including Chinese and English keywords) are words or terms that express the content information of the paper, which should reflect the characteristics of the paper, have semantics and have a clear source in the paper. The number of keywords is generally 3-8, and each keyword is separated by a semicolon. There is no punctuation after the last keyword, and Chinese and English keywords should correspond to each other one by one. Chinese keywords should be marked with "Keyword:" and English keywords with "Keyword:". Standard writing notes must be used.