Mine warfare is an old and traditional operational pattern which undoubtedly plays an important role in previous wars. The development of modern technology exerts great momentum to R & D of mine warfare equipment and leads to tremendous changes . In this article, the role of mine warfare equipment in the military domain, the developing tendency of mine and mine emplacement equipment and new technology in mine detection and clearing are described. In addition, the mine ban and mine prohibition issues which is heavily focused internationally are sourced and the basic principles of China in the R & D of non-lethal weapons as mine replacements are detailed.
Cyclotron operated within a hospital to deliver radiation to produce short life radioactive isotopes for diagnostic purpose is used in many hospitals. But cyclotron used for proton therapy is just at beginning. Proton beam therapy is a technologically advanced approach since it achieves precise radiation dose distribution. As the depth of penetration is a function of its energy, the point of energy release of the proton can be very precisely determined. The path of the proton beam is linear and causes very little secondary lateral scatter. Healthy tissues upstream from the tumor receive only a small dose and those located around the tumor and behind receive virtually none. Thus proton beam therapy is the most effective method. On the other hand, the cyclotron must be reliable, and the beam must be stable to ensure patient´s safety since the proton beam is used directly. Efficiency of beam delivery to the treatment rooms, raster scanning techniques to ensure the correct control of beam energy, intensity, and position stability, rapid and precise flexibility in changing beam parameter are also essential for satisfying clinical needs. The design efforts for developing a hsopital-based medical therapy cyclotron including the clinical beam delivery systems and integrated control system are really complex, and are less well developed than patients real need. A conception scheme for the purpose is proposed.
The Chinese agriculture is the agriculture restricted by resources. The state of agro-ecology influences agricultural development to a great extent, therefore it also influences China's economic development. This paper introduces present situation and major problems in the field of agro-ecological protection construction in China, comprehensively analyse the reasons of agro-ecologial deterioration, and puts forward proposals and strategic countermeasures for agricultural eco-environmental protection.
The increasing deterioration of the ecological and environmental conditions and the shortage of biological resources foreseen in the 21st century would pose a serious problem to China's economic development and retard the raising of the standard of living of its people. Mariculture, as a blue agriculture, which promises food from the sea is deemed to play a critical role in providing guarantee of safe food source to feed the 1.6 billion Chinese people in the new century. The course of development of blue agriculture would be approached through ecological and engineering aquaculture involving key strategies as： enhancing basic research as foothold while accelerating the application of high technology to attain rapid turnover of products; conducting “refine species project” aimed at producing high — quality breeds; overall restructuring of present mariculture sites to regulate their size and distribution to rationally balance the needs and demands among the various coastal mariculture industries; using modern biological and engineering technology to practise upper tidal zone and terrestrial ecological engineering aquaculture; with theoretical ecological aquaculture as basis, applying modern engineering technology to make use of offshore areas for developing the. “ facilities fisheries” ； promoting fishery products processing industry to ameliorate the nutritional intake structure of the people.
A clear definition and a very fine classification of the unmanned undersea vehicles are given in this paper. Following a brief introduction of the advances on the unmanned undersea vehicles the paper points out that the autonomous underwater vehicles at present is a hot spot in the research realm of the unmanned undersea vehicles. This paper describes the research and development achievements pertinent to the unmanned undersea vehicles in Shenyang Institute of Automation (SIA), Chinese Academy of Sciences with the cooperation of organizations home and abroad in the last two decades. SIA started to be engaged in the research and development of the remotely operated tethered vehicles in the end of 1970's. This paper gives a wide introduction of the critical characteristics and technical descriptions of the first remotely operated tethered vehicle “HR- 01” in China, the first autonomous underwater vehicle “Explorer” and the autonomous underwater vehicle CR-01 (6 000 m).
The technology of construction of an electronic grade polycrystalline silicon plant with annual production of 1 000 tons is explored. The product qualities, safety, transportation, storage, useful deposition ratios, deposition rates, one pass conversions, deposition temperatures, electrical energy consumption and manufacturing costs are summarized for silane, dichlorosilane, trichlorosilane and tetrachlorosilane methods. The bell jar, fluidized bed and free-space polysilicon reactors for polysilicon deposition are compared with each other. In addition, the flow charts of polysilicon production are described. The trichlorosilane method of third generation using bell jar reactors is suitable for a plant with an annual production of 1 000 tons of electronic grade polysilicon.
In this paper, a novel artificial neuron model-procedure neuron model is proposed, in which the inputs are functions or procedures associated with ‘ time´. Based on these neurons, a model named procedure neural network, which is also a feedforward network with only one hidden layer, is constructed. The authors call this neural network as Procedure Neural Network (PNN) expanded on certain base functions. The related continuity, function approximation ability and computational capability theorems are proved.
Based on results of radiate-hydrodynamic and TNT charge hydrodynamic blast wave calculations, the physical characteristic in close- in and distance regions of two kinds of explosions and the development of different blast wave systems are studied. Some important conclusions for protection engineering are obtained. Also, flood wave disasters due to two kind explosions are discussed and great meaning of protection engineering for flood wave are described.
The rapid development of industrial automation has brought favorable requirements for the chemical enterprises to carry out comprehensive automation. This article brings forward the three-strata structure of the comprehensive automation, describes it in concepts, and discusses the key problems which should be paid attention to during its process. Finally, an example project is briefly introduced on the basis of the understanding which is acquired through practical implementation of comprehensive automation for chemical enterprises.
It has been received considerable attention for surface corrosion resistance of uranium and plutonium metals. This paper is dedicated to the review of progress in the research above field in the laboratory. The surface chemical behavior and compatibility of uranium metal and U3O8 in the atmospheres of CO, CO2，H2 have been systematically studied with X-ray photoelectron spectroscopy (XPS) and gas chromatography (GC). While uranium and plutonium placed in CO atmosphere the oxidation rate of uranium was studied gravimetrically with a microbalance, and the charges of gase phase components was detected by quadruple mass spectrometer. The molecular structure, potential energy function, the corresponding spectroscopic data, thermodynamic and dynamic data of uranium and plutonium metals and compounds were systematically studied using the MP2 (the HF calculation followed by a second-order Moller - Plesset correlation) of Gaussian 94W and the RECP (relativistic effective core potential). The surface chemistry of metals were studied also by thermodynamic calculations in reducing atmospheres. The investigation indicates the metals have resistance to further oxidation corrosion in the atmosphere of CO.
To predict the risk assessment of a dam which constructs two special tunnels for unusual flood release, a method based on stochastic differential equation is developed in this paper. After analyzing the sensitivity of computational conditions on discharge risk, the requirement for useing two unusual tunnels in this project and their discharge risk are discussed, which provides a scientific basis for making decision on unusual tunnel design plan. The analyzed results show that the risk level of unusual tunnel plan can keep the same as that of the original design plan. Therefore, it proves that the unusual tunnel plan is reasonable.
To research on on-line detecting method and key technologies for part quality, based on the analysis of methods and features of on-line detecting of part dimension and surface roughness, an artificial neural network system for on-line detecting of part dimension and a fuzzy neural network system for on-line detecting of part surface roughness are developed. The Scheme of on-line detecting method for part quality can detect part dimension and surface roughness correctly.
A kind of new fuel suitable for gasoline engine is developed in this paper. To check its quality, a series of tests on process parameter in cylinder are done. The test results show that the power of engine with light oil-based fuel is close to that with gasoline and the standard errors of process parameter in cylinder with light oil-based fuel are lower than that with gasoline. This proves that the light oil-based fuel has good quality and is suitable for gasoline engine.
The development and characteristics of high dams construction in China are introduced. The scientific and technological achievements and their application in geologic exploration, dam construction, flood discharging and energy dissipation, treatment of dam foundation and treatment of high rock slope, etc. , are also described. The developing trends of high dams in the future are presented and the key research works on science and technology of high dams are indicated.
According to the incomplete statistical data, about 24 000 dams over 15 min height have been constructed, and there are 16 dams with height over 150 m to be completed or under construction. They in elude the 181 m-high concrete gravity dam in the Three Gorges Project, the 240 m — high Ertan double curvature concrete arch dam, the 178 m- high Tianshenqiao No. 1 CFRD, the 182 m- high Hongjiadu CFRD, the 233 m~high Shuibuya CFRD, the 130 m- high Shapai RCC arch dam, the 131 m- high Jiangya RCC gravity dam, etc.
Extension engineering is the application technology of extension theory and extension method. It has been applied to some engineering fields such as detection, control, management, information and computer, etc. . In this paper, its basic ideas, tools, methods and applications will be introduced.