Time flies like a song. In a blink of an eye, three years of graduate study and life is coming to an end, standing on the threshold of graduation, looking back, struggles and efforts have become memories, and sweetness and laughter have also settled. Jiaotong University has taught me to study with its excellent learning atmosphere and rigorous scientific research atmosphere, and raised me as an adult with its broad and inclusive feelings and romantic and full campus life. On the occasion of the completion of my graduation thesis, I would like to express my most sincere thanks and best wishes to all those who care, love and help me. This thesis was completed under the careful guidance of my tutor, Associate Professor Li Xia. In the past three years, my tutor's profound professional knowledge, rigorous academic attitude, work style of striving for perfection, tireless noble morality and unpretentious and approachable personality charm have had a far-reaching impact on me. My tutor not only taught me to be a man, but also taught me to be a man. Although it lasted for three years, it benefited me for life. From the topic selection to the completion of this paper, after several drafts, every step was completed under the guidance of the tutor, who devoted a lot of effort. Here, I would like to express my deep gratitude and best wishes to my tutor, Associate Professor Li Xia! The completion of this paper can not be separated from the care and help of other teachers, classmates and friends. I would also like to thank Wang and other teachers for their valuable opinions in the opening, first draft and early defense of the paper, the data and suggestions provided by the Energy Research Group of the School of Management for this paper, and the many encouragement and help given to me by my brothers and sisters in the scientific research process. Looking back on the writing process of the whole thesis, though not easy, made me not only impetuous, but also experienced thinking and enlightenment, and deeply understood the essence and significance of law, so I cherish it all the more. I would also like to thank my parents for their meticulous care, support and encouragement as always. At the same time, I also want to thank Ma Yuanping, Zhang Le, Zhao Jie and Blair for their love, tolerance and help over the past three years. May our friendship last forever! How to write a thank-you letter for a graduation thesis? Thank you for the course design paper? Thank you for your doctoral thesis? Thank you for your master's thesis? Thank you for your undergraduate thesis? Thank you for your graduation thesis? My study career is over, but the road to knowledge has never stopped. Three years of life in Jiaotong University has given me a lot of precious wealth and taught me many hard-won qualities. Study hard, be diligent and inspirational, persevere and be loyal and forgiving-this motto 16 will accompany me in my future life, bravely and constantly moving forward.