Hello, brothers and sisters, teachers, distinguished guests, parents and friends!

I am deeply honored to attend the graduation ceremony of your school; I am honored to stand here and speak. Excited but nervous: What can I do to send our blessings and hopes on behalf of the seniors when you finish your studies and are about to travel?

I never take the initiative to recall graduation, not because I lost a bicycle that accompanied me for four years two days before graduation. Mainly when I recall, I can't help but fear and marvel at the speed of time passing, and I get old unconsciously. I graduated from the school of chemistry twice, once in the last century: 1997, I graduated from the undergraduate course; Five years later, in 2002, I graduated from graduate school with a doctorate. I studied in Peking University for nine years, and spent most of my time in the chemistry building. Every time I return to the chemistry building, I have a cordial feeling and my heart is solid. When your heart is solid, what you think is easier to touch your heart. However, even if it touches my heart, my speech may not be remembered, at least I don't remember what those speakers said at my graduation ceremony. To make matters worse, I can't remember who spoke.

Here, I want to talk about my life and work after graduation from the perspective of a brother and through my own experience. I want to talk about three aspects.

First, interests and work.

Mr. Hu Shi said in his speech at 1932 Peking University graduation ceremony. The road of life is full of traps, and there are many ways to degenerate. To sum up, there are probably two categories: first, it is easy to abandon the desire for knowledge when you are a student. The second is that it is easy to abandon the ideal life pursuit of students. ?

He also said:? To guard against these two depravities, three self-defense prescriptions are worth a try. ?

First: always look for one or two problems worth studying!

Second, we should cultivate more non-professional interests.

Third: you should have a little confidence.

Sixteen years after graduation, I was deeply impressed by Mr. Hu Shi's three prescriptions.

The first prescription, because of my occupation, is easy to solve. I always have some problems worth studying.

The second prescription, non-professional interest. In my undergraduate stage, I didn't study the hardest, and spent a lot of time doing all kinds of things. I have a hobby that has been with me all my life, that is, taking pictures. All my money is spent on places related to photography. That I struggled for a long time before I graduated from my doctorate. Should I be a scientist, a photographer, a photographer or a photographer? As you can see, I especially want to take photography as my career. Later, I met a retired chemistry professor in Canada, and I talked with him about my entanglement. He told me that taking photography as a hobby can make me happy and I can always appreciate the beauty of this interest. However, if you really take photography as your profession, you may not have the opportunity to enjoy photography. Let me also think about it. If you are a freelance photographer, it is estimated that it is difficult to support your wife and children for a meal. If you open a wedding photo studio and take that kind of photo every day, it is estimated that you will be sick when you see the camera; If you are a photojournalist and find that most of your works are suppressed and cannot be published, it is estimated that you will be schizophrenic sooner or later. So, I decided to return to academia and take photos in my spare time, which is quite good. Sometimes, these non-professional interests can be very serious. For example, I have taught the elective course "Photography Science and Technology" for undergraduates in Peking University for three years, and I think it is the happiest in the teaching process. It is also my class with the largest number of attendees. In fact, there are no students in other classes. Only this class has almost as many students as those in regular courses.

In fact, apart from the entanglement of photography and academic career, I had a choice of history and chemistry earlier. My undergraduate course is to walk to Peking University. What I want most is the department of archaeology. What a fascinating experience it is to dig a grave and explore. The second one I want to go to is the history department. Third, the chemistry department, because of the chemistry competition. But in the end, I was scared. I wrote chemistry on all three volunteers and I became your brother. Looking back, this is indeed a better choice. I actually hesitated once when I graduated from graduate school. I wanted to apply for a postgraduate degree in chemical history, so I asked Mr. Xu Guangxian. Mr. Xu Can obtained a postgraduate degree in the history of chemistry. After listening to my nonsense, he said to me: Xiao Huang, do more business while you are young. There is still time to study the history of chemistry after retirement. ? After thinking about it, I still regard archaeology and history as my own interests, or it may be a problem worthy of my lifelong study, so I will continue to study chemistry as a graduate student. In fact, among the topics I am studying now, there are also topics directly related to archaeology, which is really a fate arrangement and quite good.

The third prescription is self-confidence. After graduating from the school of chemistry, I entered a very different field? Optics. The reason why I entered a non-major is mainly to expand my vision and ability. It took me about 8 or 9 months to start a normal conversation with my colleagues with very different backgrounds. However, once you cross this obstacle and move forward, it will be soon. Later I changed my major and entered the field of bioengineering. Later, I returned to Peking University, started working independently, changed my field, and now I am studying life science. As long as you have confidence, there is nothing you can't learn and nothing you can't do. I told my students that I hope you will try more things that my research group has not involved in the future, and don't stick to the research scope of my research group, so that even I can't easily surpass it. How can we surpass so many competitors outside? Go beyond me and prove that I am a good teacher. You and I both graduated from this college, and I am confident to overcome the immediate difficulties. I believe you will have the same confidence to overcome the difficulties you are facing!

Second, what to do and what not to do.

Our alumnus, brother and academician of the American Academy of Sciences, Professor Xie Xiaoliang, is now my leader. He told me several times that the most important thing for a person is to know what to do, but it is more important to know what not to do. It sounds a bit strange, but through my own experience, I feel that this is a valuable suggestion more and more. Our energy and time are not infinite, so what should we do and what should we not do? Many things that everyone says should be done may not be necessary; There are many things that people think are not worth doing. Maybe we can do it. This is a very personal judgment, but if you always know how to make such a judgment, you may be able to walk faster and better.

I have made many wrong judgments myself. For example, I was very eager to publish too many articles and dress myself as a high-yield scientist, but after a few years, I looked back and saw that everything was rubbish, mostly rubbish. Because doing these things, I am still very devoted, resulting in no time and energy to do really meaningful and valuable things. Now it seems to be the biggest waste. What kind of things are worth doing and how to choose? I want to borrow the words of an elder. My first postdoctoral tutor, Professor Yariv, was a famous professor. He not only studied well, but also successfully founded a company. One company was sold for $3 billion, which is a successful example of transforming knowledge into social value. He is also famous for writing several textbooks, which are classic textbooks in the fields of optoelectronics and lasers. In the preface of one of the books, he was a soldier when he was young. Before going to war, his officers taught him: If it is beautiful, wear it around his neck. If it works, carry it on your back. If it's neither, get rid of it. ? Do anything, it is the same.

History, a famous professor in the School of Chemistry, has the same profound experience. He told me, what should I do? Either on the shelf or on the shelf? . I have been asking myself, is what I have done really useful? Or are you polluting the environment, wasting time and misleading people?

Third, idealism.

After working abroad for several years, I returned to Peking University. In fact, what I miss most is a common one among Peking University people. Idealism? Feelings. I call it? Down-to-earth idealism? . The society is very complicated and the struggle is very hard. Many times you will be depressed, and many times you will find that the world is not as beautiful as you think, and you will sigh that people are old and the world is getting worse. But I hope you don't forget that we are all from Peking University. Peking University people have always had a heartfelt sense of pride and responsibility. I hope you can keep them well. You know, you have experienced the best education that this society can give you and enjoyed the best resources. Even if you don't realize it yourself, you have unconsciously become the elite of society and become the driving force for our progress. Don't give up easily, even if there is only the faintest hope; Don't fall down easily, even if you are exhausted. Don't easily dissolve into the stream of people and become an ordinary screw. You are from Peking University, you are not a screw, you are a screwdriver!

Bernard Shaw, a famous writer, said: Rational people adapt to the world. Irrational people try to adapt the world to them. All progress, there, depends on unreasonable people.

I also hope that you can join me and occasionally say a couplet written by Lin Zexu more than 0/00 years ago: the sea is boundless and the shore is boundless, and the mountain is the peak.

I hope you will always go back to Peking University and the School of Chemistry! I sincerely wish you all the best! thank you

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