Qian Weichang was a minor in mathematics and physics in middle school. He only got 5 points in physics, 20 points in mathematics and chemistry, and 0 points in English because he had never studied it. However, it is such a gifted student who is "lame" in mathematics and physics, but he made a bold decision overnight: abandon literature and pursue science-this decision was due to his second day in the history department, that is, in September of 193 18, Japan launched the "September 18th Incident" that shocked China and foreign countries. Qian Weichang was very angry after hearing the news on the radio. He said: I don't want to study history. I want to learn how to build aircraft cannons, and I decided to transfer to the Department of Physics to revitalize China's military strength. Wu, the dean of the department, refused his transfer request at first, but was moved by his sincerity and promised to give him a one-year probation period. In order to catch up with the course as soon as possible, Qian Weichang got up early and worked hard, shuttling between the dormitory, classroom and library. He overcame the difficulty of listening to lectures and reading in English. A year later, the course of mathematics and science exceeded 70 points, and since then, he has stepped into the door of natural science. Ye, Professor and Sabendong, Dean of the Faculty of Science, often give them lessons. At first, Qian Weichang memorized physics classics like learning ancient Chinese. Wu taught him not to think that everything in the book is correct and perfect. Every time you read a book, you should be able to see the unfinished part and find some new problems. Qian Weichang learned this, which has become the characteristic of his lifelong scholarship. When he graduated, he became one of the best students in the physics department.

The departure of studying abroad is full of twists and turns.

1On September 2nd, 939, when 22 Chinese and British students studying in the UK for the seventh time arrived in Hong Kong, unfortunately, World War II broke out, all the passenger ships going to the UK were detained by the military, and the study plans of Qian Weichang and other students were forced to be postponed. Back in Kunming, waiting for the notice, Qian Weichang borrowed the Mathematical Theory of Elasticity written by Ralph from Wang Zhuxi. After careful study, he found that the theory of elastic plates and shells in international academic circles was very chaotic at that time. Not only plates and shells were separated, but also plates and shells with different shapes had different equations. Therefore, Qian Weichang is determined to find a unified intrinsic theory based on three-dimensional elasticity. After several months' efforts, he used differential geometry represented by Gaussian coordinate tensor to represent the innovative idea of deformation and stress analysis, and actually got an unheard-of unified intrinsic theory. Three months later, after all the preparations were made by Zhongying Geng Club, he and his classmates chose to give up. Qian Weichang recalled: "Because members of the Royal Society and many professors have fled to Canada, let's study in Canada instead, saying that the head of the Sino-British Geng Fund is waiting for you in the British Concession in Shanghai. The ship has arrived. It's the Russian Queen No.5.. At 8 o'clock in the morning, I boarded the ship, and the head of the Sino-British Geng Fund gave us my passport. He said in a friendly way that when you are in Japan, you will travel by boat for three days. It's okay. You can go to Yokohama to play. As soon as we saw the visa, we got angry. Japan occupied our territory and we suffered a lot. Why do we go there with visas? The foreign students threw their passports into Huangpu River on the spot, and all 22 people disembarked. As a result, the Englishman who was in charge of the Sino-British Geng section admitted his mistake. He said that we don't understand the patriotism of China people. You go back first. " 1At the beginning of August, 940, Geng Club once again called Qian Weichang and other international students to take the cruise ship "Russian Queen" to Canada. In mid-September, I finally arrived at the University of Toronto, Canada, and began a hard study abroad career. This is also the first batch of China graduate students accepted by the University of Toronto.

Guan Xue Chinese and foreign

1940 1, a publicly-funded international student admitted by the China-Britain Geng Association, went to study at the University of Toronto, Canada. Professor Singh, Qian Weichang's tutor, is an Irish native and a member of the Royal Society. He came to the University of Toronto in Canada because of the German air raid and founded the first applied mathematics department in North America. There are professors like Infield, Weinstein and Stevenson in this department. Infield is a big disciple of A. Einstein, and he wrote The Evolution of Physics. When Qian Weichang interviewed Professor Xin Ji for the first time, he found that both of them were studying the theory of plate and shell. By using the prime tensor of macro internal force, Xin Ji obtains the tensor equilibrium equation of plates and shells under the action of external force, which is called macro equations, and Qian Weichang's equation is called micro equations. Xin Ji believes that although the mechanical quantities and symbols used by the two theories are different, the essence is the same. Professor Xinji proposed to combine the two theories, and Qian Weichang wrote a paper "Intrinsic Theory of Elastic Plates and Shells" for Professor von Carmen's birthday collection. Einstein sighed after reading it: This young man from China has solved the problem that has puzzled me for many years. This article established Qian Weichang's position in the American scientific community. After this article was published, it received great attention from mechanics and mathematics, and made cooperative academic reports at the University of Toronto, the Canadian Mathematical Annual Meeting, the Aviation Department of California Institute of Technology, and the Western Annual Meeting of the American Mathematical Society. Books have been written in Britain and Australia to further study this problem. 1973 Professor rutten of the Netherlands praised this article many times in his book Asymptotic Theory and Design of Shells, saying: "The work of Xin Ji and Qian inherited the work of A. Cauchy and S. D. Poisson in the early 9th century. He also pointed out: "The three-dimensional theory of plates and shells has not been studied for a long time because of the successful adoption of transcendental assumptions." "Xinji and Qian's work is the basic work of three-dimensional theory. Only the intrinsic variables of mechanical state, stress and strain are used, and the nonlinear equations suitable for thin shells of any shape are strictly deduced from the three-dimensional theory. Here, under the assumption of isotropy, the stress and strain components are expanded into Taylor series according to the coordinates in the thickness direction. The approximate two-dimensional equation has only six basic quantities that can be quantified, three representing the tensile strain of the middle plane and three representing the bending deformation component of the middle plane, which is the biggest feature of Singh and Qian's work. 1982, at the Shanghai international finite element conference, Professor callagher, the executive chairman, introduced Qian Weichang to the conference and said, "Professor Qian's paper on the unified intrinsic theory of plates and shells was a required reading material for graduate students of applied mechanics in the United States in the forties and fifties, and his contribution had a great influence on future work. "

Protecting London from German Missile Attacks —— Churchill's Appreciation

During World War II, when London was threatened by German missiles V 1 and V2, Churchill asked the United States for help. So this matter was transferred to the Jet Propulsion Research Institute chaired by Professor Von Carmen, a famous scientist at the University of California. At that time, Qian Weichang was engaged in the design and trial production of rockets and missiles in this institute. After carefully studying the range and shooting point of German missiles, Qian Weichang found that most German rockets came from the west coast of Europe and landed east of London, England, so it can be seen that the maximum range of German missiles is just so. On this basis, Qian Weichang proposed that the city of London could avoid being hurt by missiles as long as it created the illusion that the ground in the center of London was hit many times, so as to deceive the Germans and make them still organize attacks according to the original range, and Britain accepted this suggestion. This move is very clever. A few years later, when Churchill talked about it in his memoirs, he was grateful and praised: "American youth is really amazing." But he didn't know until the end that it was not the American youth who played with the Germans, but the China youth, Qian Weichang, who later became a famous scientist in China.