1, ask questions. At the beginning of the paper, the author should describe the problem he found or raised in as concise a language as possible, and further point out the importance of this problem in practical application. If this is not a new question, it is necessary for the author to further discuss the reasons why he raised this question again.

2. Theoretical basis and basic ways to solve difficulties. This is also the core content of the paper. In the paper, the emphasis is on whether the theoretical basis and methods to solve the problem are novel. The author has the right to fully and briefly discuss the new ideas and methods to deal with the problem and the analytical framework or model used by the author.

3. reference materials. All the creations of this thesis are based on predecessors, and the author is qualified to review the achievements of predecessors in this field. This paper not only respects the predecessors, but also discusses the innovation of this paper by comparison.

4. The structure of the paper. The last part of the paper needs to briefly explain the structural distribution of the paper, involving all chapters and their main contents except the introduction. Most of the explanations for this information can be summarized in a few sentences.

5. The length of the preface should not be too long. Too long will make readers bored, and too short is not easy to explain clearly. For a 3000-5000-word paper, the number of words in the preface is generally 200-250 words.

model essay

At present, the main research results of biomechanical analysis of pole vault in China focus on the change of speed, take-off angle and chord angle. However, the limitation of this research method is obvious: it ignores the interaction between people and poles, and there is no suitable index to reflect the ability of athletes to use pole elasticity.

Foreign countries have solved this problem by energy analysis, that is, by analyzing the changes of human mechanical energy to reflect the ability transfer between the two poles. Therefore, it is necessary to introduce energy analysis into the biomechanical analysis of pole vault in China. However, foreign literature only gives a simplified formula in energy analysis, and does not explain the specific calculation method.