I am really glad to come to Chongqing University with excitement. This is not only the first time to get in touch with the joy of college life, but also the longing for a better future. I will never regret choosing machinery, on the contrary, I will be proud, because machinery is a very good major and has a bright future. In addition, I like mechanical letters very much, and I will achieve something in the future. To tell the truth, I knew very little about machinery at first, so I enthusiastically walked into the first introduction to mechanical engineering class. At the beginning, Professor Chen took us along the way in the long history of machinery, and we got a general understanding of the development of machinery in the world, as well as a relatively deeper understanding of the history of machinery in China. Our ancestors created all the mechanical glory. Since the first industrial revolution, China's machinery has derailed and fallen behind the world's machinery. Looking at the mechanical products created by people, such as compass and seismograph, they represented the most advanced mechanical level at that time. Look at the design and working principle of the compass. I was deeply impressed by its creativity and exquisite production level. I am even sadder to hear from Professor Chen that the compass has not been repaired! Sigh the outstanding wisdom of our ancestors and the advanced machinery in ancient China. In this way, our new generation can not only enhance their self-confidence, but also study hard scientific and cultural knowledge and strive for the great rise of China! Look at today, although I am a manufacturing power now, I am not a manufacturing power, and our manufacturing level is far behind the developed countries such as the United States and Japan. It is mainly manifested in the backwardness of manufacturing technology and equipment, serious surplus of low-level productivity, serious shortage of high-level productivity, low product quality and technical level, weak technical development ability, poor basic parts and basic technology, low labor productivity, serious shortage of science and technology, weak technological innovation ability, unreasonable industrial structure and system can not meet the needs of the development of the situation. We admit our shortcomings, but we are never discouraged. We are still full of high morale and confidence, change our disadvantages, and let our machinery stand among the world's advanced manufacturing industries in quality and quantity. Later, Professor Chen showed us some pictures and videos, showing us the epitome of modern machinery manufacturing and research. Especially when I see the automatic, flexible and orderly movement of the manipulator and cutter of the machine tool, I am seldom excited. Through consulting the data, we know that numerical control technology refers to the technology of sending instructions by digital quantities and characters to realize automatic control, which is the basis of automation, flexibility and integrated production in manufacturing industry. I know the working principle of CNC machine tools: now, the information related to the parts to be processed, that is, the size parameters of bow and arrow workpieces, the processing information of cutting tools, theft and various auxiliary operations, are coded with specified words, numbers and symbols, and programmed in a certain format. Then the machining program is input into CNC device, which processes and calculates it. According to the motion components of each axis, it is converted and amplified and sent to the driving circuit of each axis. It is used to drive the servo motor, drive each axis to move, and carry out feedback control, so that the cutter, workpiece and auxiliary device can run in order in strict accordance with the sequence and trajectory parameters specified in the program, thus machining the required workpiece. This made me deeply realize how ignorant I used to be, and my awe and yearning for modern technology. With yearning, I have motivation. The second class is always full of humorous and active atmosphere, which is enough to show Professor Zhang Genbao's humorous talent and his talent higher than Croton's. Then I told some mechanical knowledge. What impressed me most was his life cycle. Look at that simple life cycle tree diagram, and you can see its rich connotation. From the needs and inspiration of society, to the design, manufacturing, testing, operation, sales and maintenance, and finally to the death and even the recycling of this mechanical product, how much professional knowledge is involved! At that time, I imagined that I would cooperate with others to complete a mechanical product in the future and then experience the life cycle of our product. Isn't this also enjoying life? Maybe it looks small and unremarkable, but can you see the efforts behind it and the rich knowledge it contains? Heart is a burst of blood boiling! Later, Professor Zhang described the development direction of modern machinery industry and his own research direction. Modern machinery is developing in the direction of giant, miniaturization, high speed, high load, high precision and green, and he emphasized the green direction of his research. Indeed, since the industrial development in the last century, environmental problems have become more and more serious and pollution has become more and more serious. Our machine is absolutely inseparable. Furthermore, with the development of the world and the rapid increase of population, all kinds of resources on the earth are decreasing, and some resources have even been exploited. The problem of resources is a worldwide problem. Therefore, the machinery industry should do its duty to meet the needs of the world and develop in a green direction. In this way, there are new research directions such as green concept, green creativity, green design, green manufacturing, green production and green treatment. Personally, I feel as if another potential force is pushing me. I have great interest and enthusiasm for green machinery and recycling. I think if possible, I will engage in the research of greening direction in the future. Then he mentioned advanced manufacturing technology. At present, advanced manufacturing technology includes advanced manufacturing technology and advanced manufacturing automation technology. Advanced manufacturing technologies include special machining, ultra-precision machining, micro-machining and ultra-high-speed cutting. Advanced manufacturing automation technology includes: numerical control technology, industrial robot, flexible manufacturing system, computer integrated manufacturing system and intelligent manufacturing system. Advanced manufacturing technology represents the frontier of modern machinery and is also our future research direction. The introduction of professors points out the future for us. It's really an introduction! Professor Xie's research direction is mechanical fault diagnosis, which really opened my eyes and brightened my eyes. He talked about the importance of fault diagnosis. If we compare machinery with people, our professor Xie is a doctor. He "sees, smells, asks and treats" machines, and predicts, diagnoses and treats their faults. In this way, the production cost and waste of resources can be greatly reduced, the product quality and production efficiency can be greatly improved, and the importance of fault diagnosis can be understood very vividly. He used his own research and work experience to show us some basic knowledge and functions of mechanical fault diagnosis. The data of the running machine is collected regularly by sensors, and then the interference information is eliminated by computer and manual analysis, and the information related to the mechanical performance is retained, and then the vibration and fluctuation of the machine are analyzed, so that the performance and working state of the machine can be obtained. In this way, the fault of the machine can be predicted and the fault position can be detected for timely diagnosis and treatment. All these were completed in a short time, which greatly improved the efficiency and brought great benefits to the society. Finally, he gave us some tips and guidance for our college study. He firmly said that the most important thing for universities is not to get the best grades, but to form a set of effective methods to solve problems. Yes, how important it is to have a systematic method of your own! In this way, our future road will be much smoother. Under the guidance of Professor Xie, I deeply realized the difference between university and high school. Universities are more important, richer and more closely linked with our future. I hope I can form my own, effective and systematic solution to the problem after four years. I will work hard, and I will complete my four-year college life with confidence. Every class is better than every class! Finally, Professor Yan Ping ended perfectly. Professor Yan introduced us to one system after another about machinery. Although the content is basically too difficult for us, it shows us the depth of machinery. But at the same time, I also realize that the research in this field in China is still immature and is under intense exploration. It can be seen that this is the frontier science of modern machinery and the research direction of our generation. Later, Professor Yan introduced her institute to us. From some information she introduced, we can know that the institute has complete facilities and made great achievements. And warmly welcome us to have the opportunity to be small assistants in the institute in the future to improve our research ability. I am a person who likes research since I was a child, so I really want to go to the graduate school to experience it when I have the opportunity, so as to lay a good foundation for my future research career (maybe). I recently read The Key to Wisdom ―― Qian Xuesen's System Science. Although I didn't understand most of them, I bravely read them and learned some systematic scientific ideas from them. Among them, system engineering is the technology of organizing and managing systems. According to the needs of the overall goal, he takes the system method as the core and comprehensively applies relevant scientific theories and methods, and uses computers as tools to analyze and synthesize the structure, environment and functions of the system, including system modeling, simulation, analysis, optimization, operation and evaluation, in order to find the best or satisfactory system method and put it into practice. Personally, I think it must be the best or satisfactory scientific system to combine the concept of system science with the characteristics of machinery itself to study a system. After these four wonderful and vivid introductory courses of mechanical engineering, I have a deeper understanding of machinery and a better vision for the future. So, make up your mind to fully enrich the field and make good use of the precious university for four years.