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81.
In this paper the reimprovement for G. I. Taylor theory of plastic deformation in impact of cylindical projectiles is done. The impulse in the reimproved theory is G. I. Taylor' s 1/2, and 3/4 of G. I. Taylor' s improved theory. The analytical solution of the reimproved theory shows that it gives better agreement with exprimental results than those of the original Taylor' s theory and, the improved theory.  相似文献   
82.
In this paper, taking a D1201 spindle as an example, we discuss the dynamic analysis of spindle by using the theory of the complex model, we also analyse the factors which effect the dynamic characterics of spindle and give results which arc reference value to improving the structure of spindle,  相似文献   
83.
The management of urban reconstruction is a process of game between the government and developers.It is helpful that the interest and its equilibrium for the relative parties involved in the reconstruction process are considered during the formation of government policy.This paper analyzes the environment for the policy constitution and establishes a model for strategy making based on the game theory.This model provides a basic foundation to improve the management ability of the government in the reconstruction process.Finally,in this paper some strategic issues are suggested to cope with the challenges from urban reconstruction in China.  相似文献   
84.
The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision.  相似文献   
85.
This peper commentaried some of our country comparatively well-known enterprise informationization estimate theory,point out,there is existing the question of informationization estimates,that the achievement can't guarantee "appropriate informationization" establishing and enterprise informationization sustainable development,It propose the three-dimensional enterprise informationization estimate the theory and method,that includes information-based level,information-based quality and information-based development potentiality.  相似文献   
86.
The aerodynamic characteristic of wind turbine is calculated by applying the Blade Element Momentum(BEM) theory.Also finite element mode analysis is done for the tower and the rotor.Then the multi-dynamic model of the wind turbine is built in Adams.Also the drive chain is calculated by applying state space method and programmed in Matlab/ Simulink.With that the combined simulation of vibration characteristics is carried out on the base of MATLAB/Simulink and ADAMS,in which the transmission effects and aero-elasticity coupling is fully considered.The results show that the method is able to simulate the vibration characteristic almost the same as software Bladed,which is well-known for analyzing performance and loads for the design and certification of wind turbines.  相似文献   
87.
In order to research the state of energy bands and gain and loss of electrons on the surface of ZnSnO_(3),it is put forward that Pinning theory of Fermi energy is applied to development of gas sensitive materials.The relative position between surface state and conduction band on surface of zinc tin complex oxide(ZnSnO_(3)) gas sensitive material has been investigated by utilizing oxidation redox couple,FeCl_(2)/ FeCl_(3),which have high surface state.Fermi energy is pinned at about 0.2 eV below conduction band E_(cs)on the surface of ZnSnO_(3).It has been determined that additives doping ratio,addition concentration and working atmosphere have no effect on this value.Therefore,pinning theory of Fermi energy has been verified by using this method.  相似文献   
88.
The method of real option has already become an important tool in the fields of enterprises value evaluation, company finance, strategy investment management, investment decision, finance analysis, corporation merger and acquisition and so on. But there is a lot of problems in both theory and practical application for the method of real option. This article will analyze the research frontier problem of real option and indicate the further research direction.  相似文献   
89.
According to existent problems on design and application of the cylindrical cam mechanism with the slide roller-follower, the one correct concept about profile design and pressure angle is presented. Based on this concept, the theoretical profile,practical profile,meshing surface equations and pressure angle formula of the cam mechanism are built up by using opp.rotation analysis and offset surface principle. This method is very simple and clear, and avoids the abstract analysing process in meshing principle. The mathematic models built by this paper can be used to design,manufacture and check this type of cam mechanism correctly, and also create conditions to make deeply meshing property analysis of this mechanism.  相似文献   
90.
An optimization approach for multi-relational joins based on the matching concept in graph theory is introduced. The basic idea lies in constructing a join graph from an expression of N-relation query, and seeking for a maximun matching with minimun total weight. The algorithm for bipartition(X, Y) is proposed in this paper.  相似文献   
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