Which scientists and scholars have given up their generous treatment abroad and returned to China to work for the motherland?

Qian Xuesen served as the technical director of China's rocket and space program for a long time, and made great pioneering contributions in space technology, system science and system engineering. Qian Xuesen published 7 monographs and more than 300 papers.

The main contributions are as follows:

① Applied mechanics

Qian Xuesen has done pioneering work in aerodynamics and solid mechanics of applied mechanics. The research on compressible boundary layer carried out in cooperation with von Carmen reveals some temperature changes in this field, and the Carmen-Qian Xuesen method is established. In cooperation with Guo Yonghuai, the concept of upper and lower critical Mach numbers is introduced into transonic flow for the first time.

② Jet propulsion and space technology

From the 1940s to the early 1960s, Qian Xuesen put forward some important concepts in the field of rockets and aerospace: in the 40s, he put forward and realized the rocket flying aid device (JATO), which shortened the runway distance; 1949, put forward the concept of rocket passenger plane and the idea of nuclear rocket; 1953 studied the possibility of interplanetary flight theory. In "Introduction to Interstellar Navigation" published by 1962, the concept of a round-trip transportation system between heaven and earth is put forward, in which a large aircraft equipped with a jet engine is the first-stage vehicle and an aircraft equipped with a rocket engine is the second-stage vehicle.

③ Engineering cybernetics

In the process of its formation, engineering cybernetics focuses on the engineering practice of designing stability and guidance systems. Qian Xuesen himself is the pioneer of this kind of research work.

④ Physical mechanics

Qian Xuesen's research on combining the physical, chemical and mechanical properties of rare gases in 1946 is a pioneering work. 1953, he formally put forward the concept of physical mechanics, and advocated to determine the macroscopic mechanical properties of matter from microscopic laws, which changed the previous method of measuring mechanical properties only by experiments, greatly saved manpower and material resources, and opened up a new field of high temperature and high pressure. 196 1 year, the Lecture Notes on Physical Mechanics edited by him was officially published. Now the leader of this subject is Professor Gou Qingquan. 1984, Qian Xuesen suggested to Gou Qingquan that physical mechanics should be extended to the engineering and technical field of atomic and molecular design.

⑤ System engineering

Qian Xuesen not only refined the practice of China's aerospace system engineering into the theory of aerospace system engineering, but also put forward the concept of the overall design department of national economic construction in the early 1980s. He also insisted on applying the concept of aerospace system engineering to the whole country and national economic construction, and discussed the social system from the perspective of social form and open complex giant system. The social form of any society has three aspects: economic social form, political social form and ideological social form. Qian Xuesen proposed to divide the social system into three parts: social economic system, social political system and social consciousness system. Corresponding to the three social forms, there should be three kinds of civilization construction, namely, material civilization construction (economic form), political civilization construction (political form) and spiritual civilization construction (ideology). The construction of socialist civilization should be the coordinated development of these three civilizations. From a practical point of view, it is social system engineering that ensures the coordinated development of these three civilizations. From the reality of reform and opening up, we need not only economic system engineering, but also social system engineering.

⑥ System science

Qian Xuesen's most important contribution to system science is that he developed systematics and methodology of opening complex giant systems.

⑦ Thinking science

Artificial intelligence has become a hot topic in the world, but academic thoughts are in a state of chaos. In this context, Qian Xuesen stood at the forefront of the development of science and technology, proposed the establishment of noeticscience Science and Technology Department, and scientifically summarized the ideas that had been discussed and debated in China's philosophical circles in the 1930s, but could not be clearly stated at that time. Outstanding contributions are as follows:

(1) In the early 1980s, Qian Xuesen proposed to establish the Department of Thinking Science and Technology. He believes that thinking science is a science dealing with consciousness and brain, spirit and matter, subjective and objective, and is a major department of modern science and technology. The need of computer technology revolution has promoted the scientific research of thinking.

(2) Qian Xuesen advocated that the development of thinking science should be combined with the work of artificial intelligence and intelligent computers. According to his personal experience in developing applied mechanics, he pointed out that the research of artificial intelligence and intelligent computer should take applied mechanics as a reference, take the road of integrating theory with practice, and actually need theoretical guidance. The theoretical basis of artificial intelligence is the basic scientific thinking in thinking science. The way to study thinking is to look for it from the achievements of philosophy, and thinking actually evolved from philosophy. He also believes that the establishment of image thinking is a breakthrough in the current scientific research of thinking, and it is also the core issue of artificial intelligence and intelligent computers.

(3) Qian Xuesen applied the systematic scientific method to the research of thinking science, and put forward the systematic view of thinking, that is, based on the thinking process of logical units, he gradually built a first-order thinking system with a single thinking type, that is, he built abstract thinking, image (intuitive) thinking, social thinking and unique thinking (inspirational thinking). The second is to solve the problem of second-order open thinking system; Finally, decision-making consultation is an open giant system with high-order thinking.

8 human science

Qian Xuesen is an advocate of human body science in China.

Qian Xuesen put forward the theory of "functional state of human body" to describe the open and complex giant system of human body and study the structure, function and behavior of the system. He believes that Qigong and specific function are a functional state, which puts the research of Qigong, specific function and TCM system theory in an advanced scientific framework and occupies an important position in the research of Qigong and specific function. Under the guidance of Qian Xuesen, researchers from Beijing Institute of Aerospace Medical Engineering began to study the functional state of human body at 1984. They use the method of multidimensional data analysis to integrate many physiological index variables measured by human body into change points that can represent the whole system of human body and its position in a multidimensional phase space composed of various variables, and move them to a relatively stable position, that is, the position of target and target ring. They found the respective targets and rings of human awakening, sleep, alertness and qigong functions. In this way, the theory of system science is embodied in the human body system, and the research of human body science has objective indicators and scientific theories.

Pet-name ruby science and technology system and Marxist philosophy

Qian Xuesen believes that Marxist philosophy is the highest generalization of human understanding of the objective world and modern science and technology (including scientific and social sciences). Qian Xuesen summarized the development of contemporary science and technology into ten closely related science and technology departments. The division method of these ten science and technology departments is another innovation of Qian Xuesen's scientific classification method by using Marxist philosophy, especially system theory.

Li Siguang lived in the countryside for nearly 14 years. Since the age of five or six, he has been studying in the private school where his father teaches, and he has to help his mother with firewood, rice, flour grinding and water fetching ... The hard life has cultivated his hard-working spirit and stubborn character.

After the revolution of Taiping Heavenly Kingdom, Westernization Schools sprang up, and many new schools were established in Hubei, aiming at learning new things and being unconventional. Li Siguang was deeply attracted. He took the exam alone and was admitted with excellent results.

In the new school, he is eager to learn new knowledge. Because he won the first place in every exam, he was selected as a formal student in the province and sent to Japan to study shipbuilding.

Li Siguang stayed in Japan for seven years, where he joined the China League led by Dr. Sun Yat-sen. ..

In the second year after Li Siguang returned to China, the Revolution of 1911 broke out, and he took part in the defense of Hankou. As a newly appointed financial department of Hubei military government, he personally organized dockers and rickshaw pullers to transport arms and go to the front. Subsequently, he was elected as the Minister of Industry of Hubei Military Government. Just as Li Siguang was about to do something great, the Revolution of 1911 failed. He devoted himself to the research of science and technology and embarked on the road of "saving the country through science". He went to study in England, first studying mining, then studying geology. He prayed that one day, he could see a politically clear world and contribute his youth and blood to the motherland.

Studying abroad is not easy. In order to maintain the rising tuition, Li Siguang went to work in the mine during the holidays. During his six years in Birmingham University, he not only achieved excellent academic results, but also mastered English, and obtained a bachelor's degree and a doctor's degree successively. After graduation, he politely refused a well-paid employment in a mine, accepted the invitation of Mr. Cai Yuanpei, returned to the motherland, and became a professor in the Geology Department of Peking University.

Geomechanics is a branch of geology, which was founded by Li Siguang. 1926 and 1928, Li Siguang published "The Main Causes of Image Changes of the Earth's Surface" and "The Law of Seawater Advance and Retreat after Late Paleozoic", which theoretically discussed the problems from hydrosphere movement to lithosphere deformation and from continental movement to tectonic features, and put forward the important concept of tectonic system in 1929, and established a series of types. 194 1 year, Li Siguang formally put forward the term "geomechanics" when he gave a speech on "geomechanics analysis of Nanling geological structure". Fundamentals and Methods of Geomechanics was published in 1945, which systematically summarized the geomechanics theory. Geomechanics is a marginal science that combines mechanics with geology, that is, a science that studies crustal structure, crustal movement and its causes based on mechanical principles. Based on the geological structure (structural trace) phenomenon, it analyzes the distribution of in-situ stress, the mechanical properties of rocks and the role of tracer force, and then traces the way of crustal movement from the way of force action to explore the law and origin of crustal movement. Geomechanics holds that tectonic unit, tectonic block and tectonic system are three basic concepts of geological structure, which is of great significance to explore the law of crustal movement. Known tectonic systems can be divided into three main types, namely, zonal tectonic system, meridional tectonic system and torsional tectonic system. These systems are mainly caused by the horizontal movement of the crust (meridional and latitudinal); The horizontal motion originates from the change of the earth's rotation speed. Li Siguang called the earth's function of automatically adjusting the speed change "continental valve function", so he called this hypothesis "continental valve hypothesis".

John E. S. Han

John E. S. Han (1894— 1968) is a chemist and an expert in instrumental analysis. He devoted his life to scientific research and education, actively organized and led the Shanghai Society of Chemistry and Chemical Engineering to carry out academic activities of instrumental analysis, and trained a large number of scientific and technological talents. His monographs "Introduction to Instrumental Analysis" and "Index of Polarography Literature Content" are quite famous in China, and they are the pioneers of polarography research in China. It has contributed to the development of instrumental analysis in China. Originally known as Han Enshu, her English name is Johane.s.han1894165438+1was born in Baoqing County, Hunan Province on October 4th. 1898 took the whole family to Chaling. /kloc-moved to Changsha in 0/905 and lived with his grandfather. He has been studious since he was a child. 1900 1906 I studied three amethysts, hundreds of surnames, Qian, The Book of Songs, The Analects of Confucius and other ancient texts. I have been influenced by China literature since I was a child. At that time, imperialism invaded our country, the Manchu government was humiliated and the people of China were in dire straits. He believes that China's poverty and backwardness are mainly due to underdeveloped science. To make China rich and strong, we must revitalize science. He especially liked chemistry when he was in middle school. /kloc-when he was 0/4 years old, he wrote a chemistry book himself, and his father arranged and bound it for him. 19 10 In February, he was admitted to Yali University in Changsha. Because of his poor family, he paid tuition and books for the school by copying and lettering. Later, due to his outstanding academic performance (first place in the exam), he won a scholarship and was exempted from all expenses. When he was studying in the university, he was determined to devote himself to the chemistry in our country.