At the completion of the thesis, I would like to thank my tutor Mr. XX for his warm care and careful guidance. In the process of writing my thesis, Teacher X devoted a lot of effort and sweat. No matter in the topic selection, conception, data collection, research methods and final writing, I have been carefully taught and selflessly helped by Mr. X, especially his extensive knowledge, profound academic accomplishment, rigorous academic spirit and meticulous work style, which have benefited me all my life. I would like to express my sincere thanks and deep gratitude here.

In the process of writing my thesis, I also got valuable suggestions from many classmates, and I also got the support and help from many colleagues in the work process. I would like to express my sincere thanks here.

Thanks to all my mentors and friends who have cared about me, supported me and helped me.

Finally, I would like to express my heartfelt thanks to the experts who took time out of their busy schedules to review this article and put forward valuable opinions!