A scientific research achievement or technological innovation is often not accomplished by one person, but also needs the support and help of human, financial and material resources from all sides. Therefore, many papers have listed "thank you" at the end. I am mainly grateful for the help I got in the process of completing my thesis, which is a sign of humility and courtesy in academic circles.

The copyright of a paper should be registered voluntarily, and whether the paper is registered or not will not affect the copyright obtained by the author or other copyright owners according to law. The voluntary registration system of works in China is to safeguard the legitimate rights and interests of authors or other copyright owners and users of works, help to solve copyright disputes caused by copyright ownership, and provide preliminary evidence for solving copyright disputes.

(1) The references at the end of the article are not numbered, but arranged in order of importance or references. (2) No page number is indicated in the references. (3) The description items and order of the references are basically the same as the notes. 1) Recording references can reflect the author's scientific attitude and the true and extensive scientific basis of the paper, as well as the starting point and depth of the paper. 2) Recording references can easily distinguish the author's achievements from those of predecessors. 3) References can serve as an index. 4) Recording references helps to save the length of the paper. 5) Recording references is helpful for scientific and technological information personnel to carry out information research and abstract quantitative research.