Growing up in such a family, Zhang Gongqing showed his ancestors' education, integrity and talent in his bones from an early age. When I was in junior high school, my father instructed Zhang Gongqing to read classical literature, but he didn't show special interest. He likes every subject in the school very much, and visiting bookstores in his spare time has become his greatest pleasure.
When he was in the second year of high school, he saw a mathematics publication "Mathematics Bulletin" issued for middle school mathematics teachers in the bookstore. Every issue of this publication has a "question-and-answer column", which gives five math questions to collect answers from readers, and the names of people who have done the right questions will be announced later.
Zhang Gongqing was fascinated by this challenging problem-solving activity. When he saw his name appear in the list published in Mathematical Bulletin, his heart was filled with a sense of accomplishment. Zhao Xianchu, his middle school math teacher, discovered Zhang Gongqing's talent in mathematics and actively encouraged him to apply for the Department of Mathematics.
1954, Zhang Gongqing was admitted to the Department of Mathematical Mechanics in Peking University, where many masters gathered, and has since wandered in the ocean of mathematics. Shortly after entering the school, the school put forward "teaching students in accordance with their aptitude" and organized scientific groups in different directions. He was assigned to Mr. Cheng Minde to specialize in "Mathematical Analysis". With diligence and talent, Zhang Gongqing quickly showed his advantages. In the first semester, I wrote a book report on establishing the concept of real number with bilateral rational number series. In the second semester, he gave an elementary proof of the necessary and sufficient conditions for Riemannian integrability, without measurement theory.
However, a series of sudden political movements interrupted Zhang Gongqing's pursuit of mathematics. He became a "typical white expert", and his pure mathematics was considered as a "pseudoscience" divorced from reality and useless.
He wanted to do something for the country. He went to the factory and asked if there was any place where he could use mathematics. The answers he got were all negative. "Over the years, this incident has had a great impact on me." Perhaps because of this, Zhang Gongqing paid more attention to the application of mathematics. 1959 When he graduated from Peking University, Zhang Gongqing, a "typical white college", was ready to work in a hard place. Unexpectedly, his name appeared on the detention list, and the school clearly told him: "Your task is to teach." Under the extraordinary teaching burden and political pressure, it is difficult for him to have time to study and do research systematically.
Zhang Gongqing has not lost confidence in mathematics. He firmly believes that "mathematics is the foundation of all sciences" and the achievements of mathematical research are contributions to mankind. Not only that, he also proved with practical actions that "mathematics is useful."
With keen insight and understanding of mathematics, Zhang Gongqing seized every opportunity to solve practical problems with mathematics. 65438-0975 Assisted the Institute of Physics of Chinese Academy of Sciences to solve the calculation problem of magnetic surface balance in the controlled thermonuclear device. From 65438 to 0976, I went to Huabei Oilfield to understand the "water cone problem" in oil exploration when the bottom of the oil well was flooded.
He found that these two problems and a large class of free boundary problems can be abstracted as "partial differential equations with discontinuous nonlinear terms". In order to solve the theoretical and computational problems, he reduced it to finding the fixed point problem of a class of set-valued mappings, and developed the topological degree theory of set-valued mappings in cooperation with others. Since then, he has developed the "critical point theory of non-differentiable functional" for this kind of problems from the perspective of variational theory.
These two theories have become the pillars of theoretical functional analysis of partial differential equations with discontinuous nonlinear terms, and won the third prize of National Natural Science Award 1982 for their theoretical and methodological innovations, which are still widely cited by mathematicians all over the world.
On the basis of solving practical problems, Zhang Gongqing abstracted a higher level of mathematical theory, and took a key step on his mathematical road.
When China's mathematics community woke up from the nightmare of ten years of catastrophe, great changes have taken place in the world's mathematics research. In order to fill the academic vacuum, 1978, Zhang Gongqing went to the United States as the first visiting scholar in China after the "Cultural Revolution", and was introduced by the famous mathematician Chen Shengshen to the Courand Institute of Mathematics in new york for further study.
In an academic report in the United States, Zhang Gongqing introduced the mathematical theory developed to solve several practical problems before going abroad. Because of its application background and unique treatment methods, it attracted the attention of international colleagues and was invited to give lectures at more than 0 universities in the United States and Canada/KLOC-0. But Zhang Gongqing is not satisfied with this. He is determined to make full use of the superior conditions of Courant Research Center and move towards the mainstream of mathematical research.
Zhang Gongqing seized the opportunity of the rise of critical point theory in nonlinear analysis and successfully applied morse theory to multiple solutions of asymptotically linear equations. His paper was recommended to be published in the influential Communication of Pure and Applied Mathematics, which was the first paper that completely applied Morse theory to nonlinear differential equations, and was also a famous work by Zhang Gongqing. Professor Chen Shengshen introduced him to study abroad.
Before going abroad from 65438 to 0978, Zhang Gongqing, an associate professor in the Department of Mathematics in Peking University, made some research achievements in the field of mathematics.
Zhang Gongqing recalled: "During the Cultural Revolution, China was isolated and helpless, and its academic level was far from the international frontier. However, out of my love for mathematics, I often study in the dead of night. When we encounter practical problems in production, we all try to make it clear from mathematical theory. Therefore, in the mid-1970 s, several mathematical research papers with applied background were published. "
After Nixon's visit to China, foreign professors came to China to give lectures. Whenever possible, Zhang Gongqing will look for opportunities to listen to and understand academic development. 1977, the school returned to normal order. 1978 In May, Zhang Gongqing was promoted from teaching assistant to associate professor, and was immediately selected by the school to study in the United States.
The mathematicians of the older generation in the Department of Mathematics in Peking University have a deep friendship with American professors. They have introduced Jiang Boju and his situation to Professor Chen one after another and asked him to help contact American schools for further study. Professor Chen Shengshen knew that Zhang Gongqing was interested in partial differential equations, so he introduced him to Professor nirenberg of Courand Institute of Mathematics. Courand Institute of Mathematics was the world center in this field at that time, and Professor nirenberg was the academic authority in this direction. Zhang Gongqing took part in a discussion with him when he came to China to give a lecture. Soon, Zhang Gongqing received an invitation letter from Professor nirenberg. He hurried to study English and prepare to go abroad.
Remarkable academic achievements in the United States.
Unlike other visiting scholars in the United States, Zhang Gongqing did not attend English training in Washington. After spending 1979 New Year's Day in China Liaison Office, he went to Courant Institute of Mathematics in new york alone. Three months later, the first batch of public visiting scholars, Ying Long An and Wang Jinghua, also came to the same institute. They shared the same apartment provided by the institute.
Zhang Gongqing said: "Although we encountered many difficulties in life and language, we helped each other, made concessions to each other and got along well. In particular, everyone realizes that as the first batch of public visiting scholars, it is a great responsibility. They not only pay special attention to the image of China people in their contacts, but also work very hard in their studies. "
Zhang Gongqing recalled that during his time as a visiting scholar, he eagerly attended lectures, lectures and discussion classes every day. "There are too many things to learn, and I work until midnight every day."
After getting familiar with the environment, Zhang Gongqing gave an academic report in Courant University, which was about the mathematical theory developed to solve several practical problems before going abroad. Because the problem has application background and the treatment method has its own characteristics, it has attracted the attention of peers. 1979 In the summer, at a grand international academic conference held in California, Professor nirenberg introduced Zhang Gongqing's research in the conference report. After the meeting, Zhang Gongqing was invited by many universities in the United States and Canada 10 to give academic reports.
But Zhang Gongqing is not satisfied with this. He is determined to make full use of the superior conditions of this research center and move towards the mainstream of mathematical research. At that time, a new direction in nonlinear analysis-"Topological Variational Method" was emerging, and Zhang Gongqing actively devoted himself to the research and made a breakthrough, which led to a lot of follow-up work.
The Mathematical Research Center of the University of Wisconsin-Madison focuses on the development of nonlinear analysis, and a group of promising young scholars and powerful peer experts from all over the world work here every year. The following year, Zhang Gongqing was invited to visit the 1 year research center. After two years in the United States, his research work is unique and famous among his peers. Before returning home, he was invited by colleagues from France, Germany, Italy, Switzerland and other countries to give lectures in Europe for three months.
Thanksgiving for studying abroad for the first time
Zhang Gongqing, who has achieved fruitful academic results, is deeply grateful for his experience in studying abroad. He said: "sending overseas students is an important part of the strategic deployment of reform and opening up. Personally, studying abroad has changed the academic destiny of our generation, enabling us to get out of the backward and closed academic environment and come to the world academic center to learn skills, display our talents and enhance our self-confidence. "
Zhang Gongqing said: "In the past 30 years, thousands of young students have traveled overseas to study, thus creating a large number of China elites and architectural talents. These are all attributed to the great decision of reform and opening up. " 198 1 year, Zhang Gongqing returned to the Department of Mathematics in Peking University after visiting abroad. Since then, he has devoted himself to establishing the research team of "Nonlinear Analysis" in China. Many of his students and colleagues have now become excellent mathematicians.
"Mathematics has reached an unprecedented period of brilliant development." After returning to China, Zhang Gongqing played an important role in serving, guiding and leading the development of mathematics in China. In the past, mathematics was not widely used in China's industry, agriculture, finance, management and national defense. With the rapid development of economy and society in China, the application of mathematics in various fields has become the most concerned issue in Zhang Gongqing. He said: "I am also encouraged to see that mathematics has various applications."
As for the value of mathematics, Zhang Gongqing also has a deeper understanding: "Mathematics has become the core of high technology, the forerunner of exploring new knowledge, the core of human rational culture, the treasure of human wisdom and the source of innovation ..."
After half a century's addiction, mathematics is no longer just a career choice that Zhang Gongqing strives for, but also a spiritual pursuit of being a teacher and friend.
In the late 1980s, a student in Zhang Gongqing wrote only a short sentence in the thank-you part of his graduation thesis: "Thanks to my tutor Professor Zhang Gongqing for his concern and support for my research topic." In the eyes of many students, this kind of gratitude is a bit incredible and seems to be a disrespect for the tutor. However, Zhang Gongqing said that the student's gratitude was "very accurate", and in the field of mathematics, accuracy and intuition are the most important things. "It is generally acknowledged that Mr. Chen Shengshen is a perfect man," Zhang Gongqing, an academician of China Academy of Sciences and a professor of Peking University, said with tears when he visited Mr. Chen Shengshen, a teacher who had been in contact with him for many years and an international master of mathematics, at Nankai University.
Zhang Gongqing said that his contact with Chen Shengshen for more than 20 years has benefited him for life. At the end of 1978, China sent the first batch of 50 scholars abroad for further study. Zhang Gongqing and another academician of China Academy of Sciences, Jiang Boju, are the only two representatives in the field of mathematics. It was because of Chen Shengshen's help that they were chosen. Chen Shengshen, who was at the University of California, Berkeley, wrote to the Courant Institute of new york University and Princeton University, respectively, and recommended these two China people to the best mathematics professors in these two universities. The rest haven't decided where to go.
"Teacher Chen has made careful arrangements and his help to us is endless." After Zhang Gongqing went to the United States alone, he became a stranger and wandered around the new york Railway Station. Chen Shengshen was very careful and specially invited Professor Wang Hao, a logician at Rockefeller University, to pick up Zhang Gongqing at the station for a week. I never thought that he would associate with Mr. Chen before. Although I heard that he was very modest and concerned about his younger generation, he didn't expect that he could get Chen's recommendation. He said that Chen Shengshen was the first great mathematician he met. On 1972, he heard Chen's speech in China and was deeply impressed by his knowledge. Chen is a world-famous mathematician. He is just an ordinary math teacher. "He can only look at Mr. Wang from a distance, and his heart is full of admiration."
From 65438 to 0983, Chen Shengshen invited Zhang Gongqing to work in the National Institute of Mathematics. The more contact they have, the deeper they know each other. Zhang Gongqing admired Chen Shengshen more and more: "Needless to say, Mr. Chen's great achievements, what impressed me the most was his character." "Everyone sincerely respects Mr. Chen because he is a great patriot. He is modest, but very self-respecting, confident, proud of China people, and has the traditional virtues of China people. Many foreign mathematicians respect him very much and regard him as the elder of the family. He is completely at ease with these people. Such people are rare. " Zhang Gongqing still remembers that Bobby Chen invited all China people who were studying mathematics to dinner and encouraged them.
In Zhang Gongqing's view, Chen Shengshen played an irreplaceable leading role in the faster progress of mathematics in China than other disciplines after the reform and opening up. When the domestic scientific community was still in a closed state, Chen Shengshen returned to China to give lectures many times, and everyone first came into contact with Atia-Singer Theorem and other mathematical frontier topics from him. After the reform and opening up, Chen Shengshen saw the spring of science in China, and returned to China more often and for a longer time. "Teacher Chen opposes the occlusion of the scientific community and advocates openness. After the opening up, he encouraged the people of China to follow their own path. " Zhang Gongqing thinks that the influence of several great events that Chen Shengshen did on China is immeasurable: the "Double Micro" conference initiated for seven consecutive years has greatly developed China's differential equations and differential geometry. At the International Congress of Mathematicians in 2002, China scored the best in these two fields. Established Nankai Institute of Mathematics, held academic year meeting, and trained a large number of young people; The "Chen Shengshen Plan" selected a large number of outstanding domestic talents to go abroad for further study; The first national summer school for graduate students in mathematics. Under the leadership of Chen Shengshen, the domestic mathematics has made remarkable progress and promoted the development of other disciplines.
In 2002, the International Congress of Mathematicians was successfully held in Beijing. Zhang Gongqing, then Chairman of chinese mathematical society, recalled that one of the important factors for the success of the meeting was Chen Shengshen's support. He said that Chen Shengshen is not only an advocate, promoter, consultant, but also a hero behind the scenes. At the beginning of the bid, Zhang Gongqing and others sought the support of mathematicians all over the world. The first sentence of these mathematicians is often: "What is Professor Chen Shengshen's attitude?" After learning Mr. Chen's opinion, they expressed their support for China. If people encounter any problems in the preparation of the meeting, they will immediately call Chen Shengshen for help. Chen Shengshen came forward to contact the leading figures in the field of mathematics in various countries to solve this problem. Grateful to say: "Although we can't find a lot of work he did behind the scenes in Mr. Chen's biography, everyone knows it."
Zhang Gongqing last saw Chen Shengshen in the middle of June this year. Mr. Chen called Zhang Gongqing and said, "You haven't been here for a long time." Zhang immediately rushed to Nankai University to visit and live in Ningyuan, an apartment in Chen Bulei. Two people talk about a wide range of topics together, but most of them are related to mathematics.
Zhang Gongqing said that it is gratifying that Chen Shengshen has a successor in her career. Through the establishment of Nankai Institute of Mathematics, Chen Shengshen introduced the model of running an international institute of mathematics into China. Drawing lessons from the experience of the National Institute of Mathematics of the United States and the successful practices of other research institutions, he insisted on running schools and holding academic years, and invited the best mathematicians in the world to communicate abroad, which was unique in China at that time and set an example.
Zhang Gongqing will remember a sentence that Chen Shengshen said all his life. One day, Zhang Gongqing solemnly said to Chen Shengshen, "I admire you very much and want to learn from you how to be a man first." Chen Shengshen replied: "I have nothing, I just totally contributed to mathematics." Zhang Gongqing said that Mr. Chen really devoted himself to mathematics. He devoted his whole life to cultivating mathematical talents, especially those in China, and developing the mathematical cause in China. At the beginning of this century, some people were willing to accept the auction of Zhang Peilun's letter manuscript, and the starting price was100000 yuan. Today, its market price is unimaginable. It is admirable that the Zhang brothers and sisters donated all these precious manuscripts to the Shanghai Library for free. Yesterday morning, the reporter interviewed Zhang Gongqing and Zhang Gongci in the hotel.
Account-free donation
He told reporters that his father, Mr. Zhang, had asked his brothers to carefully keep and properly handle these manuscripts before his death. This year, Zhang Gongqing was nearly eighty years old, and his younger brother Gongci was also over the age of seventy. The two brothers have been trying to find a good home for this batch of materials. When Zhang Gongqing visited Fujian Normal University with his family (its predecessor was founded by another late Qing official's grandfather Chen), he saw a plaque in the library, which read: "It is better to keep books in private than in public." This inspired Zhang Gongqing to donate.
After returning home, Zhang Gongqing and his younger brother Zhang Gongci reached an understanding of * * * after careful discussion, and got the consent of her younger sister Yoko. His wife and sister-in-law also support the initiative of "free donation". Therefore, Zhang Gongqing and his younger brothers and sisters naturally thought of donating all Zhang Peilun's letters and manuscripts to the Shanghai Library, and they chose to settle in the above picture, largely because their father donated rare books to the above picture in the 1980s.
Nearly 300 precious documents were donated this time. Before the donation, Zhang's brothers and sisters did not count the exact number of letters and manuscripts because of their trust in the Shanghai Library. These materials were originally stored in seven large camphor boxes and catalogued by Shanghai Library, and all the fragments were recorded. Only 29 A4 sheets were printed in the catalogue. Zhou Deming, the deputy director of the above picture, said that the donation ceremony was postponed until today because he was busy counting and sorting out donations for fear of betraying the trust of donors.
Suffering literature
It is a blessing for historians that these manuscripts and ancient books can escape the war. Zhang Gongqing remembers that when he was a child, his house was full of books, but ancient books and manuscripts were kept in secret. During my stay in War of Resistance against Japanese Aggression, my father, Zhang, did not cooperate with the Japanese invaders and worked as a clerk in a bank. Many large families are often unable to uncover the pot, but he has never thought of selling these ancient books. "My father cherishes these treasures very much. Our family has never even seen the ancient books donated to the above picture in the 1980 s, nor have we seen these manuscripts and letters. "
Later, these manuscripts fortunately escaped the catastrophe of the "Cultural Revolution" and were stored in a unified way after the property was looted. After the Cultural Revolution, the Zhang family took back all the materials in the name of private communication. In addition to donating ancient books, Zhang Gongci and his wife Jiang perennial take care of manuscripts and letters and keep them properly. Only when the book is printed and the moth-proof pages are inserted in the book will the couple pay more attention. "We can't understand some letters." In recent years, people have been blowing around the couple, saying that these cultural relics are very valuable, and Zhang Gongqing and Zhang Gongci have never wavered.
An orderly manuscript
Zhang Gongqing said that more than 4,800 volumes and 100 volumes of letters were arranged in an orderly manner, including letters received by Zhang Peilun and letters sent by him, which made the historical materials coherent and of great textual research value. This is due to the careful collection and mounting of Zhang Peilun's son and grandfather, Mr. Zhang. He even repurchased the letters sent by Zhang Peilun from the correspondence object.