The contributions by H. S. Tsien to modern mechanics and engineering sciences, especially his work on a series of key problems in aerodynamics, solid mechanics and jet propulsion, are introduced. Through his work, many new branches of engineering sciences were established, such as engineering dybernetics, physical mechanics, jet propulsion science, etc. The embodied foresight and realistic spirit are highlighted. Today in China, it is of great practical significance to advocate and carry forward his noble spirit, and to strengthen the research and development in the field of engineering sciences.
After a brief introduction to the contents, method and meanings of cybernetics and control engineering with a brief historical remark, Professor Qian Xuesen's《Engineering Cybernetics》is introduced with special emphasis on its contents, paradigms, and the important role it plays in the development of control theory from the “Classical” to the “Modern”. In the preface he stated , “Engineering cybernetics is an engineering science, which aims to organize the design principles used in engineering practice into a discipline and thus to exhibit the similarities between different areas of engineering practice and to emphasize the power of fundamental concepts”. With his modern work on systems engineering, large-scale systems, complex systems and complex giant systems, a new frontier of control science will be formed to meet the challenges of complexities in modern society and technologies
An advanced way for controlling desert and sandstorm to protect, recover and expand wetland in north and northwest China is proposed in this paper. The necessary conditions for increasing precipitation in inner continental basin contain mainly three aspects ： westerlies, high mountains for condensation and broad wetland fog as vapour resources . A scheme of project is envisaged, which introduces sea water from Bohai Sea through north Inner Mengolia to Xinjiang. The target of the project is to recover and expand wetland in northwest China. It will produce economis and ecological benefits in the aspects.
Heavy force sensor is a kind of high-technology electric information device for heavy equipment. In this paper the purpose, properties and development of heavy force measurement for heavy equipment are described .The physical model of heavy force division measurement mode is discussed. The super-miniature adhesion type of heavy force sensor invented by the auther and its engineering application are introduced.
A new process for soda ash production based on converted gas, developed by China is very competitive in the world. However, it is difficult to manufacture the large size carbonization tower because of its special structure. Therefor the process has only been used in the small soda ash plants for years. Newly developed large size carbonization tower has been put into operation recently. Disadvantage of traditional Solvay technology has been overcome by using this new process. The developed technology will surely promote further progress of soda ahs manufacturing based on converted gas, and hence enhance the competitive capability of China´s soda ash industry on the international market.
At present, under the condition that the water resource is deficient day by day and the worsen trend of water environment is becoming severe increasingly, as well as the advanced and super advanced treatment and the reuse of waste water have been practicable, drainage system should not only be the basic facilities for draining rain and sewage and protecting city environment and water quality of pubic water basin, but also be sublimated to the lifeline project of human society that maintains healthy water cycling and good water environment and realizes sustainable utilzation of water resource. As a valuable drinking water resource, sewage has attracted more and more attention. The article elaborates on the author´s new ideas and concepts about the function, programming and design of drainage system.
This paper analyzed the kinematics and dynamics of the 6-DOF platform, and adopted CMAC Neural Networks as controller to realize tailing track. Simulation results showed that the analysis of kinematics and dynamics was correct and the controller had the capabilities of resisting disturbance and good robustness.
A linear analytic solution is derived for wave interaetion with a combined cylinder with a solid interior column surrounded by a coaxial porous exterior column. The solution is established on an eigenfunction expansion of velocity potential and a linear model between the fluid velocity inside a porous wall and the pressure difference between two sides of the wall. Numerical experiments have been carried out to examine the wave force and wave run-up on combined porous cylinders with different porous coefficient, porous section, and ratio between the radii of the interior and exterior columns. It is found that the porous rate of the exterior wall and the size of the porous section have a significant influence on the wave run-up and wave loads on cylinders. Cylinders with whole porous section on the outer column are more suitable for reducing wave loads and wave run-up on cylinders.
A knowledge-based variable-structure decoupling is developed, and be utilized to control a nonlinear multivariable system, so as to avoid the model-establishing process, especially avoid large amount of complex matrix operations required for the conventional decoupling control. Some modules in the knowledge base of this kind of control are described, and the main points of the related algorithms are introduced. Strategies described in this paper have been successively utilized to the set-point temperature control of a 3 × 3 strong coupled system —a three winding heater type standard temperature source, and an effect that the temperature stability as well as temperature homogeneity all better than 1℃ has been attained, which is impossible for the conventional control method.
Based on adsorbent theory and the law of energy change, the degree of interaction on the surface is determined. The adsorbent layer is defined. Analysis calculation formula on the thickness of adsorbent layer is obtained. The thickness of adsorbent layer is the most critical factor for thin film lubrication research, and is a critical point to the difference between thin film and thick film analyzed. According to the theory of interaction of molecules and basic definition of hydromechanics, correcting model of viscosity with exponential function is derived. It can be used to determine the law of change of fluid viscosity in micro-clearance, and thus the rationale is provided for theoretic model of thin film lubrication established.
In this paper, focusing on practical engineering application of Finite Element Model (FEM) updating technology, the authors discuss some key problems and bring forward their own points of view. This paper explains the basic thought and numerical method of a FEM updating approach that has achieved the level of practical engineering application. This paper also presents the difficulties in the practical engineering application of Finite Element Model (FEM) updating technology, and indicates the ways by which those difficulties can be solved.
A (TiO2 + B2O3 + Al2O3 + TiB2)/NiCrAl metal-ceramic coating was fabricated on a steel (Chinese brand 40Cr) surface by laser. TiB2, Al2O3 were introduced by an in-situ reaction of Al, B2O3 and TiO2 during laser cladding process. The microstructure, phase, element distribution and micro-hardness were analyzed with the aid of microscope, X-ray diffraction, electron probe and micro-hardness tester. Experimental results show that the γ-Ni, γ´，AI2O3 and TiB2 are the dominant phases in the cladding zone. Laser processing parameters as well as the chemical composition of coatings determine the microstructure and hardness of the cladding layer. The hardness and the boundary strength are significantly enhanced due to the presence of ceramic in the coating.
New technology of waste liquor from papermaking was provided by researching the treatment of waste water from pulping plant. The new technology incorporates evaporation and spray drying to the treating system of waste liquor. The technology of combining evaporation and spray drying was studied, practiced and concluded. Its economic analysis was also done. It was proved that not only zero discharge of extracted waste liquor could be realized, but also the lignin products were obtained by using this new technology.
The Three Gorges Project (TGP) is a vitally important and backbone project in the development and harnessing of the Yangtze River. Since TOP started eight years ago, a matured and complete quality assurance system has been established with the whole process, full direction and sliced quality adiminstration. The quality of the project has been controlled effectively and the result is quite good and accords with the require-ments of design. Based on a detailed introdution of the TGP quality assurece and quality control, the paper give some suggestions and views about the work in the future.
In February 2000, U.S.A worked out the strategy of National Nanometre Technology (NT), which evoked worldwide repercussions . Japan and Europe also successively worked out their development program of NT. As a new forward branch of science , NT will become a core driving force of causing a new round of material revolution in the 21 st century and exert an immense influence on the field of aerospace. This paper simply introduces the definition of NT, nanometre materials, and the research and development status of NT.
With more and more strict environmental requirements, copper smelting industries are facing severe challenge. Flash smelting, one of the most competitive smelting technologies in the world, is considered as a standard and clean copper production method. At present, 50% of the global blister copper is produced by such technology. Due to its well meeting with the general trend of sustainable development strategy, flash smelting is widely introduced to most newly built smelters and smelting expansion projects. This article gives general introduction of the specialty of flash smelting technology and its following development. It also describes the current situation of copper industry in China and suggests the development tendencies.