查看更多>>摘要：That flow is the common feature of substance flow and fluid flow is the viewpoint emphasized in the paper.Some notes on fluid mechanics, including the two approaches of fluid flow description, were given. The concepts of the chain and the chain group of product life cycles , which are essential for understanding the specific features of substance flow, were advanced. Taking the specific feature of substance flow into consideration, on the analogy of the two approaches in fluid mechanics, two approaches of substance flow analysis, e. L method and E model, were formulated. Illustrative models of steady and unsteady substance flow were sketched by both methods , and comparison between them was made in general.
查看更多>>摘要：The development history of the project design of spaceflight launching site in China and the main forms used in these designs were introduced in this thesis , and it was pointed out that the spaceflight launch should not use only one fixed model. According to its nation condition, China should design and build the launching project facility and device which correspond to the technology development of spacecraft and carrier rocket.
查看更多>>摘要：This article introduces three outstanding innovations, e. utilization of the steel casing for the piles to establish a construction platform for Sutong Bridge' s large and deep-pile groups; 5000 ton steel cofferdam lowered as a whole and used as a protective structure against impact from ship collision; Permanent scour protection. This article also presents economical and reasonable design method for large bridge foundation and explains the significance of innovation and technical integration to large and complicated project construction based on the above theory.
查看更多>>摘要：A novel broad concept of numbers was given out based upon the analyzing of numbers' carrying rule. In international mathematics & computer science, all researches on numbers are only confined to same varying rule of the FCN (fixed carrying numbers). The concept of VCN ( variable carrying numbers) was presented, and some applied examples of practice were given out. So the engineering application of VCN for n-figures is wider than that of FCN in human society.
查看更多>>摘要：Accidents in a nuclear power plant are coped with by operators in the main control room ( MCR). An analysis of the workload of operators in a MCR after the happening of initiating events is helpful to the alleviation of human errors and to the promotion of training efficiency. This paper establishes a framework of how man is located in a man-machine interface of a nuclear power plant ( NPP) as well as a simulation of the man-machine scenario in accidents in NPPs, including the simulation of the operators' task and cognitive work and the establishment of task analysis. On the basis of the above, a model of the dynamic changes of the operators' tasks is constructed and a computation of operators' workload is conducted.
查看更多>>摘要：Effects of operating conditions and device' s geometrical sizes on geometrical properties of wall-attaching transonic jet between two parallel plat plates are numerically simulated. Conclusions are as follows: 1) Upriver part of the wall-attaching jet' s center streamline is in good accordance with parabola; 2) When both gas inlet pressure and outlet pressure as well as their ratio are not too high ( the outlet pressure is less than 10 MPa and the pressure ratio is less than 3) , the center streamlines of the wall-attaching jet with the same pressure ratio coincide with each other very well, and the deflection degree of the center streamline decreases with rise of the pressure ratio; 3) The deflection degree of the jet' s center streamline decreases with either broadening of nozzle' s throat or rise of wall offset; 4) With rise of the pressure ratio, attachment distance of the jet increases, but the increase rate descends ; 5) The attachment distance ascends with rise of either the nozzle' s throat or the wall offset.
查看更多>>摘要：Considering the dynamic character of repeated games and M arkov process, this paper presented a novel dynamic decision model for symmetric repeated games. In this model, players' actions were mapped to a Markov decision process with payoffs, and the Boltzmann distribution was into iduced. Our dynamic model is different from others' , we used this dynamic model to study the iterated prisoner' s dilemma, and the results show that this decision model can successfully be used in symmetric repeated games and has an ability of adaptive learning.
查看更多>>摘要：According to the physical and chemical characteristics of superfine powder extinguishing agent, three test methods are selected to measure the flow ability. By studying and comparing various test methods, apparatus and conditions,the optimum method and conditions to test flow property of superfine powder extinguishing agent are confirmed.
查看更多>>摘要：To accurately track computer viruses, an overlay network that monitors the activities of viruses is constructed.Identifying and locating nodes infected by virus on network is achieved by a naming system in which a node in the network is mapped to a unique serial number of the hard -drive. By carefully monitoring and recording sensitive communication between local system and remote nodes on the network, and suspicious operations on files that originate from remote nodes and entered via some form of file transfer, activities of viruses in both local and network level are recorded and ready for future analysis. These data can also be used in analysis of the mechanism of a computer virus as well as its spreading mode and pattern.
查看更多>>摘要：The buildings construction safety problems contain various safety-hidden dangers that caused by the human unsafe behaviors, the substance unsafe conditions, operation environment unsafe factors and management defects. The authors summarize comprehensively the problems of buildings construction safety in China at present based on grasping the whole safety status of buildings construction, and the synthetic countermeasures including the systems about laws,management, technology and education civilization for buildings construction safety management are brought up based on the viewpoint of safety system theory. Then it is thought that building scientific management mechanisms and popularizing effective management methods and measures are the fundamental wavs for improving further the level of safety management for buildings construction in China at present.
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