Editor's Note

The Xinya College Class I offered in the autumn semester of 2023 falls under "Value and Consensus", one of the five general education course groups of Xinya College. This compulsory course is designed to help freshmen better adapt to the study and life of the university and college community from three perspectives: "the spirit of the university", "the meaning of life" and "the wonderfulness of disciplines". The small classes of Xinya College Class I for freshmen enrolled in 2023 are taught by seven teachers, each with a maximum of 15 students.

Here is an interview of Mr. Liu Pei, an associate professor and doctoral supervisor from the Department of Energy and Power Engineering of Tsinghua University, by students Fang Lihang, Hu Yunche and Zhang Jingxin—one of the course assignments made by Ms. Lin Weiran.

Q1. Why did you choose the Department of Thermal Engineering for your undergraduate studies?

After receiving my college entrance examination result, I asked Mr. Li, a teacher of the Undergraduate Admissions Office at that time, about Tsinghua University's majors. He recommended energy-related majors to me, especially the one focusing on thermal engineering. Inspired by his words, I unhesitatingly made the Department of Thermal Engineering my first choice. Later, Mr. Li became my supervisor. At the undergraduate stage, I focused on the study and research of thermal conversion and power systems.

Q2. Why did you decide to go abroad after getting the bachelor's degree?

I had planned to go to the United States for a doctorate after graduation. At that time, I was very interested in academic research but there was still a certain gap between Tsinghua University and certain foreign universities in terms of scientific research platforms and resources. I was basically qualified to apply to any university in the United States. However, affected by major international terrorist attacks, the domestic policies of the United States underwent drastic changes and the enrollment of foreign students was almost suspended, so I chose to remain at Tsinghua University for a master's degree. Later, I learned by chance that Imperial College London in the United Kingdom would recruit a student from the Chinese mainland to pursue a doctorate in energy system engineering. This major was in line with my research program and the duration of doctoral studies was only three years in the United Kingdom, so I decided to go to the country for further study.

Q3. Did the experience of studying in the United Kingdom bring you special gains different from those in China?

The learning experience in Imperial College London made me truly feel academic inheritance, and the research group I was part of enjoyed a high reputation in the global systems engineering field. My supervisor, a very influential professor, has mentored lots of top students, many of whom are professors at renowned European and American universities. This kind of academic inheritance has benefited me greatly.

Q4. How has the experience abroad affected your life?

My years of experience abroad has enriched my values and worldview. There are many excellent museums around schools in the United Kingdom, such as Science Museum, Natural History Museum and Art Museum. In that country, I developed a habit of feeling life through museums. Now, I especially like Tsinghua University Art Museum. This habit has enabled me to experience different lifestyles and enriched my life.

Q5. What is your current research focus?

My research has always been related to systems, ranging from the undergraduate study of circulating fluidized bed simulators, to the master's and doctoral study of coal-based polygeneration systems, and the current study of low-carbon energy systems, all of which involve the conversion and utilization of fossil energy. For example, the circulating fluidized bed can utilize inferior fuels that cannot be used before, but its chemical reaction and energy conversion need to be further studied. In the research process, I used the method of systematic analysis to analyze the system law in different coupling scenarios of energy conversion processes and develop quantitative analysis tools.

Q6. Is there any useful experience in scientific research?

In scientific research, the means of systematic analysis are also very important besides experiments. Under normal circumstances, it is difficult to obtain consistent results from large-scale or scaled-down experiments due to such limitations as the irreversible loss and the size of the system. However, systematic analysis provides clearer explanations and allows us to deduce unknown laws based on the known ones. For example, in the research on coal-based polygeneration systems, we consider how to couple coal-based electricity production with chemical product production through systematic analysis to improve energy conversion efficiency.

Q7. How do you align your research with the dual carbon goals?

The dual carbon goals require exploration of the coupling with renewable energy. We study how to better integrate coal-based systems with the existing and even future new energy systems to consume more renewable energy.

Q8. How do you make choices in the face of numerous disturbances?

In my opinion, everyone has to make both active and passive choices. Active choices are usually made based on interest, while passive ones are usually made under external pressure or due to various coincidences. No matter in our career or daily life, we all have to face these two types of choices. So, take it easy. Scientific researchers of universities are freer compared with those in other industries, which may lead to more unrestrained thoughts and research orientations in their fields of study.

Q9. Do you have any suggestions for freshmen in choosing directions and conducting scientific research?

When making choices, one often finds himself entangled in a dilemma. Excellent people are used to maintaining excellence so they would worry that the current path is not the best. But sometimes that's not the case. For example, if you choose to communicate with another teacher instead of me today, you may gain something different. Similarly, personal development should be multi-dimensional and different dimensions may feature different selection criteria. However, if you don't fear the "consequences" of your choice but keep a positive attitude, are willing to try and spend time and avoid overthinking the value and efficiency, you may make a better choice. You should also be clear that the complete determination of goals is impossible because individual cognition is limited. As long as you are convinced that you should do it, this choice is basically right.

Q10. You just mentioned that you often visited the surrounding museums when you were in the United Kingdom, and there are many books on literature and history such as Zizhi Tongjian, or Comprehensive Mirror to Aid in Governance, and Shiji, or Records of the Grand Historian on your shelf. What are your thoughts on general education?

General education is a very "luxurious" endeavor. I didn't start reading books like Zizhi Tongjian until I was over 40. When I was a student, the university resources were insufficient so we had to compete for seats or even queue up to enter teaching buildings. I often go to museums now because I didn't have a chance to access those works before. My teachers told me how good Qi Baishi's paintings are, but I didn't understand their charm until I saw them myself.

General education is a guarantee of students' all-round development. It is not limited to literature, history and philosophy education. It is also important for students majoring in arts, literature, history and philosophy to understand science and engineering thinking. The cognition of nature and the objective world as well as the study and comprehension of history are all important. General education essentially aims to cultivate a way of thinking and a way to view and communicate with the outside world.