Environment simulation technology is a new developing peripheral technology,which mainly covers artificial man-made reappearance techniques of all kinds of nature environment and product test techniques under the simulated environment. Environment simulation equipment and environment test techniques have gone through the development from single parameter to multi parameters, from static simulation to dynamic simulation, from product environment tests to man-machine system environment tests. At present its development direction is to establish the comprehensive dynamic environment simulation equipment of a whole system with parameters and to conduct multi-parameter comprehensive dynamic environment tests, and man-machine system environment tests. Prableme could be identified and explained in a faster way through reappearing all kinds of environmental conditions in environment simulation equipment, to product environmental reliability tests, which is important for new product development and finished product quality inspection.
This article summarizes the production status of gasoline and diesel oil in China. It shows clearly the evolution trend of the quality of gasoline and diesel oil and the principle of exploiting clean fuels productive technology.
China had introducted three species plants of Spartina genera from Britain and America since 1963, namely Spartina anglica S. alterniflore and S . patens. Now the 3 species of Spartina plants are widely distributed throughout coast zone of 18 000 km, and growing area reaches to 36 000 hm2 along seabeach of China. The facts have proved that Spartina adapt itself to the natural seabeach environment of China and grows well. Spartina is a valuable plant for reforming seabeach land,e. g. the ecological functions of creating land with silt, protecting seacoast, as well as its economic benefit. On the other hand, it is a pioneer plant for the formation of plant community in seabeach. Spartina as a foreign plant species has been listed in the books of Flora Chinensis, Iconographia Cormophytorum Sinicorum and Flora Hebeiensis, etc. Spartina´s benefits and faults ought to be objectivly evaluated. Because of the eutrophication in its waterbody, the Spartina s rate of reproduction is very high. However, there are no injuries to environment, population and humanity. And up to now no abnormal phenomena have been observed in the coast zone of North China. Therefore Spartina alterniflora and S. anglica are not ecological invasion species.
China´s tactics in the production of wheat after its accession to WTO is as follows： Raisng the benefit of wheat production relying on the advanced cultivation techniques, adjusting the structure of wheat growing, developing wheat of high guality, raising wheat for special purpose, raising the proportion of production marketed, processing wheet deeply, linking production with marketing, increasing the sales volume of wheat, raising the content of science and technology in wheat growing, making full use of the Blue Box Policies of WTO to support the production of wheat.
This paper discusses the development of aeronautics and astronautics with mechanics, reveals the development of new branches of interconnected sciences in mechanics, describes the relations of flight mechanics with aerodynamics, structure mechanics, general mechanics and automatic control, and introduces the new branch of flight mechanics—flight dynamics of elastic vehicle.
The implementation of proliferation and culture of marine fishes is the fundamental measure and effective avenue for the reasonable and sustainable exploitation of marine fish resources. Therefore, the establishment and development of modern techniques for the proliferation and culture of marine fishes is one of the important research areas in the marine biotechnology. The reproductive physiology and endocrinology, the growth and developmental biology, the immunology and the molecular biology are the theoretical basis of the proliferation and culture in marine fish. Deeply and systematically carrying out basic research and applied research of these disciplines nowadays has become the frontier and major research direction of the science and technology for marine fish.
Mechanics of jointed rock masses is a new branch derived from mining engineering and engineering mechanics. Aimed at the practical problems in mining engineering, this paper reviews the recent developments in mechanics of rock masses and its applications, including damage mechanics of rock masses and its applications, and fractal theory and applications of mechanics of rock masses. Moreover, a development tendency of mechanics of rock masses, i. e.，the scientific points and key techniques for prevention of engineering catastrophes and slection of mining method of deep mining, is discussed in the paper.
The space remote sensing and information technique have become a necessary tool to observe the different scale, different layer and continuous dynamical phenomenon of oceanic resources and environment. The marine remote sensing has more advantage than the normal investigation in the collection of marine environment parameters of several yeas, even several ten years. In the 1970s the international scientists began the real time detection of oceanic environment by means of water leaving radiance measurement from satellite. China has paid great attention and has made great progress in this field since the 1980s. This paper, first, reviews the development of marine optical remote sensing in China over the last 20 years. Secondly, the neads of this technique in national rights and interests, preventing and reducing natural calamities and management and development of marine resources are discussed. Finally, the key technique and frontiers of the application of marine optical remote sensing in the monitoring of marine environment are expounded, such as marine satellite operational monitoring system, accuracy analysis and quantitization, high frequency and long term monitor data collection, the combination application of multi sensor and key technique, etc.
The shock tensile stress-strain curves of 93% wt. tungsten alloy at different strain rates εand different temperatures T were measured experimentally by use of a Hopkinson tensile bars equipment. Based on these experimental data, two constitutive models were proposed to represent the shock tensile behavior of this alloy. Besides, a linear relation between the critical strain ε1 of plastic instability and the plastic work W1 at the maximum load-onset of instability was derived, so that the criterion of shock tensile fracture of the material is given in this paper. The fractal analysis to the tensile fracture was made which gives a strong support to the conclusions obtained from the macro-experimental results.
In this paper, the Bayesian method, an estimate method for parameter in reliability engineering is put forward. The author gives definition of the new Bayesian estimate for failure probability and failure rate, and shows the estimate of the failure probability and the failure rate by new Bayesian method. Finally, calculations are performed regarding to practical problems, which show that the new Bayesian method is feasible, easy to operate, and convenient to use for engineers and technicians in fieldwork.
A novel algorithm which is based on space contraction for solving MINLP problems is proposed. The algorithm applies fast and effective non-complete evolution to the search for the information of better solutions, by which locates the possible area of optimal solutions, determines next search space by the information of elite individuals. The result shows that it is better than other existing evolutionary algorithms in search efficiency, range of applications, accuracy and robustness of solutions.
Hydrostatic bearing has many advantages, such as high accuracy of movement, low power consumption of friction, small deflection of bearing center, high capacity of load-carrying, powerful absorption of vibration and long life of operation, etc. But gcx>d static performance can fully be displayed only under good dynamic performance of hydrostatic bearing. The moving and rotating accuracy are determined by its static performance and working conditions are decided by its dogmatic performance. According to mechanic balance and flow continuity, the transfer function of hydrostatic bearing system is established in this paper. On the basis of this transfer function, the new formulas of dynamic performances, namely the formulas of system stability, dynamic stiffness, nature frequency, maximum amplitude are derived. The bearing clearance of hydrostatic bearing with new variable, restrictor can be controlled in constant or near constant. But the clearance of hydrostatic bearing with constant restrictor may be changed into little clearance at the loading on it. Therefore, there are many differences between their dynamic characteristics.
In recent years, Cellular Automata (CA) micro-simulation has emerged as an effective technique for modeling traffic flow and achieved a lot of success. But the human movement and occupant evacuation are much more complex than traffic flow. It is necessary for us to consider more human behavior characteristics if try to apply the model in practice. For the advantages of agent in simulating human intelligence, a multi-agent model based on CA is presented which focuses on simulating the human behavior and the effect on human by building structure. In the model, people are represented by agents and they move over the network which is represented by a lattice of cells. Agents can perceive the local environment and chcx)se their moving direction autonomously. In order to simulate human movement in very complex structure building the acquainting and evacuating states based on the ideas of artificial life are introduced and that is proved successful in simulation. Using this model the effect of the building structure on human behavior can be studied and the performance of building design can be assessed.
The “Technique of continuous extraction and converse retention” is used to separate effective ingredients from soybean. The cost of soybean concentrated protein(purity is higher than 70% )is firstly reduced to less than 2 200 yuan/ton, which is 1/3 of the cost of the same kind of food in domestic and international market. Adding 5%〜8% soybean concentrated protein to flour, the content of soybean protein of staple flour food will increase by 3.5%〜5.6%. In addition, processing quality of staple flour food will be improved While the price of flour or staple flour food remains unchanged.
It is a great challenge facing all leaders of state-owned enterprises (SOE) of how to enhance the competitiveness and viability of the enterprises in the severe international competition. In this paper, two key elements in the enterprise management——“personnel” and “systems” are discussed, the dialectical relationship of their essence is studied, and thus the “personnel and systems management” idea is developed. Talents and scientific & technological innovations are critical to the core competitiveness of the state-owned enterprises; as for the viability, there is no choice but system innovations. “Choosing qualified persons” is key to ensuring the competitiveness and viability of the state-owned enterprises and “establishing a new systems” is the basis. The efforts of China Aerospace Science and Industry Corporation in carrying out the “Personnel and systems management” idea and the results are elaborated in this paper.
Concerning with status of rock burst study, some comments on rock bursting mechanical models, laboratory experiments and numerical analysis are made. Some research fields related to rock bursting are reviewed. Finally, some views on rock bursting research are put forward.
In 2002 summer, a new book titled RECENT ADVANCES IN FASTER THAN LIGHT RESEARCH by Prof. Huang Zhixun was published, covering a wide field of theoretical and experimental progress in the faster than light research . The book is divided into three parts to discuss relevant research work in different areas, including theories and experiments on superluminal phenomena, anomalous dispersion and negative group velocity (especially the experiment of superluminal light pulse propagation by L. J. Wang et. al.), the achievements and paradoxes of wave-particle-duality theory, the EPR thinking and the research advance on neutrino´s mass, etc. This is a good book with novel and abundant contents, written in a concrete and vivid style and so it will be quite attractive to broad readers. In this paper a view-point that the academic free discussion is a prerequisite for the development of science is emphasized