Editor's Note: In a sense, life as small as a person, a […]
Editor's Note: In a sense, life as small as a person, as large as a nation and nation or even the future of our entire mankind, and the future of the entire universe are governed by invisible laws, so they are actually A math problem. Given the correct answer, is it possible to reap the successes; giving the wrong answer will accept various punishments. Mathematics is the basis of modern science and is closely linked to our daily life and productive activities. Numerous scientists indulge in mathematical research and are diligent about the truth, though they may not be able to achieve the breakthrough. Just as science fiction writer He Xi said in his work Sad Heart: "There should be something that should not be over-rewarded, and you should not ask them to grow beautiful leaves and flowers because they are root "Mathematics is the root of the flower of science. However, the society is realistic. Research needs rewards. Simple theoretical research is often "useless" and unsustainable. Therefore, it is still necessary to do research based on production and living practices. Professor Zhu Peicheng, School of Science at Shanghai University and Institute of Materials Genome Engineering, has long been devoted to teaching and research in the field of mathematics and insisted on cross-discipline innovation. This law has been deeply and firmly enshrined in the developed countries such as the United States and Germany. This will enable the benign interaction and mutual promotion between scientific research and engineering and technology, thus leading the international community in a long-term and comprehensive manner. In our country, there is such a researcher who recognizes the style of scientific research and works hard. He is Professor Zhu Peicheng of Shanghai Institute of Science and Materials Genome Engineering. He has long been devoted to teaching applied mathematics with strong industrial background. And scientific research, in the field of material science has made a series of fruitful results.
Zhu Peicheng, Professor of Distinguished Professor, Shanghai "Thousand-Year Plan". He has held positions in several countries and holds tenure in Europe. After innovative research, successfully established two phase field models that describe structural phase transitions in smart materials such as shape memory alloys. For the outflow problem of compressible Navier-Stokes equations in fluid dynamics, the nonlinear wave classification is the first to be performed, and the asymptotic stability of several kinds of waves is proved. The establishment of a priori estimates of fineness has solved the outstanding problems of the thermo-viscoelastic equations such as shape memory alloys and solid-like materials for several decades.
Obsessed with mathematics, illusory
What is mathematics? Mathematics can be said that one of the oldest disciplines, long-established, although experienced many crises, but always overcome and grow. As of now, even mathematics can not fully understand the maths branch outside his / her field of expertise, and there is often the feeling of interlacing across mountains.
The idol of Ju Pei-cheng was a boy named Hua-Geng Geng, known as the "father of modern Chinese mathematics." Hua Luogeng is an internationally renowned math guru, he founded the Chinese mathematics school and led several areas to achieve world-class level. All this left a deep impression on Zhu Peicheng's young mind.
Due to the worship of Hua Luogeng, Zhu Peicheng began to have a strong interest in mathematics. Interest is the best teacher, is the biggest driving force for research, with extraordinary talent, he was on the road to math learning can not be achieved, from middle school to doctoral, Zhu Peicheng never left this area.
"At first, the discipline of mathematics was very sacred. At that time, it was not a propaganda that" we should learn mathematics well and not be afraid of going all over the world. "But learning to learn and confusion came." With the deepening of the research, Zhu Peicheng gradually found that what he had learned-math-did not appear to be significant for the entire scientific promotion, social advancement, and economic development, but at the same time, , Mathematics is a basic discipline, other disciplines and even linguistics (such as voice analysis), will be more or less applied to mathematics, as an indispensable tool for the development of other disciplines, as Marx said "any The subject can become a real science only if it is fully applied to mathematics, "so that the value of the math profession can not be underestimated. A discipline created by human pure thinking can accurately describe the objective world, The development has played such a huge role, from the micro to the macro, from the natural sciences to engineering to the social sciences, many of the laws are written in mathematical equations, which is how magical! This understanding, so he once caught in tangled, Continue to delve into the meaning of the big big in the end? Mathematical majors how to study and use it to become a "ground gas Discipline, can really solve problems and to work closely related to people's daily lives?
This knot, until Zhu Peicheng completed post-doctoral research in China did not fully open. He remembered that his idol Mr. Hua Luogeng had gone to Europe and the United States for further studies and played a key role in his scientific research. He also thought of China's old saying that "reading thousands of books and traveling thousands of miles" made Zhu Peichen determined to go Go out to find the answer, look at the world from another perspective, look at one another from an angle. As a result, he opened up to 15 years of overseas study and working life, the first stop is Kyushu University in Japan, get the Japan Society for the Promotion of Science as a special researcher for foreigners. Recalling the first step gingerly when he took the first step, Zhu Peicheng joke he was very lucky, met a lot of good teachers, like "Lu Xun met the same Mr. Fujino," they gave themselves a lot of care and confidence to make their own every step Go very solid.
During these ten years, he has been teaching and researching at internationally renowned Kyushu University in Japan, Darmstadt University of Technology in Germany, Basque Applied Math Middle School in Spain and the motherland of Basque Country, as well as in mathematics institutes such as the Humboldt University in Berlin, Germany, Bonn University Mathematics Institute, Kyoto University Institute of Mathematics and Mathematics, Poland Banach Center for Mathematical Studies and other world-renowned Institute of Mathematics, the opportunity to face the face of international mathematics masters (such as J. Ball, PLLions, etc.) to learn, making Zhu Peicheng gradually have With a very high international perspective, it maintains close cooperation with internationally renowned research centers and thus has a more accurate grasp of the direction of international mainstream development.
These experiences also let Zhu Peicheng personally understand the different scientific research culture, let him have an eye-opener and breathe a lot of fresh air that is completely different from the domestic one. For example, he found that rather than relying on the number of papers to prove your level here, the quality of the essay is more important than the quantity; a relaxed research environment here is more likely to stimulate one's potential for free thinking; and this easing is not the same as having no Order relaxation, in Germany, a punctuation in the research papers in the end should be a comma or a period, the mathematical formula behind the strict implementation of the space have to be considered well, this rigorous scholarship attitude so that Zhu Peicheng breathtaking and benefited.
In such an environment, Zhu Peicheng can think more freely of various kinds of problems. For example, as the scientific development is getting more and more developed, the disciplines are very small and the boundaries between disciplines become more and more blurred. , Where is the science going? What kind of scientific accomplishments should scientists have? What is the value of scientific theory? And he also gradually realized that everyone is equal before science, and even the masters of science sometimes make mistakes. The real The master, instead of being ashamed of wrong, finds the wrong amendment or the fundamental re-establishment of a new theory, so the scientific understanding is a spiral. As far as mistakes are concerned, the gap between east and west is great. He also realizes Only when we have our own thoughts and form our own ideological system can we claim scientists in the true sense of the word, and scientific theories end up as human beings themselves, which is the value of its existence. If the theory can not solve practical problems, then it is complicated Also useless.
Zhu Peicheng realizes that mathematics is a very special subject. Unlike other natural sciences and social sciences, it does not have an objective phenomenon to test it. Logically correct it is right, in the sense that mathematics is not even a science. But mathematics, even pure mathematics, undoubtedly useful, is the language of the natural sciences, social sciences. Imagine: Without mathematics, Newtonian mechanics has no precise basis and no modern science. Nearly three hundred years later, in the twentieth century in which physical science was rapidly advancing, Einstein built Newtonian mechanics and established the theory of relativity, based on partial differential equations. The advent of quantum mechanics, leading us to develop infinite dimensional space, which in turn provides a solid theoretical basis for quantum mechanics. In addition, computer science is more connected with mathematics. Many phenomena in material science can be described by evolution equations, and some even use group theory as a branch of pure mathematics. . Even in the social sciences, mathematics is being applied more and more. Without mathematics as a tool, it is difficult to be precise and difficult to move away from. For example, the demographic model, the option pricing model and the game theory are differential equations , Operations research, etc., some achievements won the Nobel Prize.
Therefore, Zhu Peicheng realized that mathematics is so far away from our intuition, but describes the world well. As a mathematical reflection of an approximate abstract world, the mathematics formed by some pure thinking achievements is It truly describes our complex earthly world that seems seemingly irregular but can be rationally recognized. Many seemingly totally different phenomena can be described by the same differential equation, etc., and so on, which is The greatest marvel of mathematics as the greatest achievement of human rational thinking. Mathematics is very useful for other disciplines, on the contrary, if not closely integrated with other disciplines, the power of mathematics will inevitably be greatly reduced, and perhaps this is a major source of mathematical unnecessary; and if mathematics left the other disciplines, It will lose the direction of development, lose its blood with healthy growth! They are mutually influential, spiral promote each other.
In order to better link mathematics with reality, Zhu Peicheng has studied a lot of modeling techniques abroad, and there is hardly any domestic involvement in this field. In addition to math majors, he also mastered many interdisciplinary knowledge of solid state physics, crystallography, and materials science foundations for modeling. However, the direction that he had troubled his math major also gradually found answers in his overseas experience, gained a deeper understanding of the various types of models he had previously encountered, and Zhu Peicheng established his own scientific philosophy, which is It is clear that applied mathematics is more meaningful and can yield significant results only when it is closely integrated with other scientific fields. Therefore, he designed a detailed scientific research roadmap for himself: First, select the physical phenomena of great significance, the establishment of mathematical models; and then make theoretical analysis of these models and computer simulation, and then compared with the experimental results to determine the pros and cons of the model; Finally Based on the validated model, various numerical simulations are performed. These numerical simulations can be used to better understand the physical phenomena and guide the application. For example, in his view, the study of maths in materials science is a promising area that has promoted the development of a new discipline called solid math.
After realizing this, as described in the ancient poem "The Bright and the Fantastic Village," Zhu Peicheng suddenly found himself at the foot of the road where he did not know where to go and suddenly became cheerful.
Memory alloy, the new interdisciplinary materials science results
Material and our human food and clothing are closely related. The modern life of our life is more and more manmade and artificial than ever before. The discovery, invention, and use of these new materials have greatly changed the way modern people work and live. For example, smart materials such as shape memory alloy, used in the warship fasteners, has successfully accumulated millions of spare parts has been successfully no longer happen oil spill; all kinds of new materials used in the Airbus A380 this air giant, super Large aircraft, enabling occupants up to twice the number of passengers carrying the largest aircraft, but the machine weight, wingspan, fuel consumption, etc. is much less than twice the original volume of the largest aircraft, so that we can be more comfortable and cheaper Traveling. Without new materials, smartphones are impossible. The food we eat every day, is also constantly creating new varieties. Another example is the superalloy, as the country has not been able to produce aircraft (especially civil aircraft) engine used, high temperature oxidation resistant high temperature alloys, our engines and large aircraft can only buy the western countries, Therefore, research and development of high temperature alloy as a major national project. In short, for a country, new materials are crucial for ensuring economic security, national security and maintaining a prosperous human life.
Unlike the ancients, which basically used only natural materials, we nowadays make and use more man-made materials more than any other time in history, and the invention of these new materials has greatly changed the way modern people live and work . Therefore, material science as a new science has become the hottest cutting-edge research field in the 21st century.
How to design new materials to meet our needs is a central task in materials science, especially in the ascendant material genomics program. In addition to mathematics, Zhu Peicheng said that it involves disciplines such as mechanics, physics and computer science. It is an interdisciplinary research and development platform with numerous achievements. Mathematical models play an extremely important role in this field.
An important starting material for Zhu Peicheng is shape memory alloy. For the first time in 1932, the Swedish Aulandian "memory" effect was observed in gold-cadmium alloys, that is, after the shape of the alloy has been changed, it can magically return to its original shape upon heating to a certain critical temperature , People have called the alloy with this special function as shape memory alloy. Memory alloy development so far, however, more than 80 years, but because of its application in various fields of special effects, is widely attracted worldwide attention, known as the "magic of functional materials."
Zhu Peicheng studied shape memory alloys early during his Ph.D. study because of its role too broad and too powerful. There are many successful examples of the use of memory alloys in the aerospace field. Huge antenna on the satellite can be made of memory alloy. Before launching the satellite, the parabolic antenna is folded into the satellite body. After the rocket launches the satellite to a predetermined orbit, it simply needs heating and the folded satellite antenna naturally expands to restore the parabolic shape because of its "memory" function. Memory alloys also have a wide range of applications in the clinical field, such as artificial bones, calcaneal compressors, various types of endoluminal stents, embolizers, cardiac prostheses, thrombus filters, surgical sutures and the like, Modern medical care is playing an irreplaceable role; and memory alloy with our daily lives are equally relevant. For example, a spring made of a memory alloy is used as an example. The spring is placed in hot water and the length of the spring is immediately extended. The spring is returned to cold water and it immediately regains its original shape. The spring of this material controls the water temperature of the bathroom plumbing and regulates or shuts down the plumbing through the "memory" function when hot water temperature is too high, avoiding scalding. Can also be made into fire alarm equipment and electrical equipment security devices. When a fire occurs, the spring made of the memory alloy is deformed and the fire alarm device is activated to achieve the purpose of alarm. It is also possible to place a spring made of a memory alloy in a warm-air valve to maintain the temperature of the conservatory and to automatically turn the heating valve on or off when the temperature is too low or too high.
As a new class of functional materials, many new uses of memory alloys are being developed even beyond the imagination of many people. "example