English keywords: font No.5 titled "Times New Roman" is bold, and the first letters of the two words should be capitalized, placed in bold square brackets and placed in the top box; There is a space between the back content and the bold square brackets in front, no other punctuation marks are used, and the font "Times New Roman" No.5 is used, which is not bold.

Keyword definition

Keywords are selected from the title, abstract and text of the paper, which are words with substantial meaning to express the central content of the paper. Keywords are words used by computer systems to index the content characteristics of papers, which are convenient for information systems to collect and provide readers with retrieval. Generally, 3-8 words are selected as keywords for each paper, and a new line is set at the bottom left of the "abstract".