The preface is equivalent to the beginning of the paper and is the first paragraph of a three-stage paper. The preface and the abstract are not exactly the same, so the abstract should be highly summarized and concise, and the preface should be more specific, with the text of 1000 words or so.

The preface should generally include the following contents:

1. Why do you want to write this paper, what problems to solve and what are the main points?

2. Comment on the existing literature within the research topic of this paper.

3. Explain the problems to be solved in this paper and the research methods, approaches and methods adopted. Define the boundary and scale of research work.

4. Summarize the results and significance of this study.