Fault Section Diagnosis Algorithm of Distribution Networks Based On Topology Identification     

LIN Jing dong  CAO Chang xiu  ZHANG Bang li  WU Jian lin 《保鲜与加工》2001,(5):51-54

An algorithm of fault section diagnosis based on topology identification for distribution networks is presented. By decomposing the topologic matrix which describing the distribution network into two parts,one part only contain the complex coupling factor ,and the other ignore the complex coupling factor. Using this method, the fault zones in distribution network can be identified and isolated efficiently, and the vertexes of the zones can also be identified automatically. This approach adapts to the changefully network structures.  相似文献   

A Detecting Method of Harmful Currents in Three-Phase Four-Wire Asymmetrical System     

ZHOU Lin  YI Qiang  QIN Mei  ZHOU Xiao jun  YE Yi lin 《保鲜与加工》2002,(10):9

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Synthetic Application for Analysis Methods of the Planar Mechanism Overconstraints     

AN Pei wen  HUANG Mao lin 《保鲜与加工》2002,(5):21-24

Overconstraints exist widely in planar closed chain mechanisms and mechanical systems result in a series of detrimental influences on behavior of machines, and attention is given to them by machine designer. Some analysis methods of overconstraints in planar closed chain mechanisms are presented, and more study due to the faultiness of these methods. In accordance with faultiness of two common kind of methods, formulas method and loop analysis method of degrees of freedom, and by combining these two methods, an useful mechanism overconstraints analysis method which is convenient for computer aided overconstraints analysis is gained via research on the two methods thoroughly and systematically, and some new views about mechanism overconstraints analysis are presented.  相似文献   

Density Functional Theory Compute on Electronegativities to Superconductivity of Oxides     

HONG Quan 《保鲜与加工》2001,(6):117-119

In this article we have worked out the correlation between electronegativity and high temperature superconductivity for oxide. It is suggested the equalized electronegativity, X cq , can be used as a empirical criterion for superconductivities of oxides. For determining the X cq , a new formula for the calculation of X cq values has been obtained The X cq values of 230 oxide superconductors have been calculated. The result shows that the X cq values of all the oxide superconductors concentrate in a narrow range from 5.00 to 5.63 and that the oxides with values out side this region would be non-superconductive. This criterion can be applied to almost all the oxide superconductors. It is clearly that this result is able to benefit further inquiries about the mechanism of superconductivity.  相似文献   

Optimization of Energy Dissipation Braces in Frame Structures     

WU Ze hou  ZHOU Fu lin 《保鲜与加工》2002,(2):47

In this paper, the complex method of the nonlinear programming is used to optimize the parameters of energy dissipation bracing in energy dissipation braced frame. This method is realized with computer program and proved to be efficient. A 6-story reinforced concrete frame is used as a demonstrative example.  相似文献   

Research on Cooperative Design Network Security Based on IP-VPN     

FU Hong qiao  HE Yu lin  XIAN Zhi ling  WANG Xu xia 《保鲜与加工》2002,(4):32-35

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.  相似文献   

Knowledge Representation for Rotative Machine Fault Diagnosis Based on Semantic Net     

LI Tai fu  HUANG Mao lin  XIE Zhi jiang 《保鲜与加工》2001,(6):18-20

Aiming at knowledge representation problem of expert system for rotary machinery fault diagnosis, semantic net knowledge representation is discussed. Semantic net to represent expert knowledge of rotary machinery fault diagnosis is explored. Its realizing method is afforded in computer language, in addition, demostrating model is also developed in Visual C++. The result shows good validity of the knowledge representation.  相似文献   

The Application of Pre-splitting Blasting to Excavation on High Slope in Soft Rock Section     

KANG Hui ming  LI Xiao hong  LI Tong lin  JIN Xiao guang  LU Yi yu 《保鲜与加工》2001,(1):47-50

Based on analyzing about blasting mode of slope in the construction of road, the paper shows that pre splitting blasting is mostly suitable in the section of severely weathering soft rock with developed joints and fractures, introduced the laying out about the hole of pre splitting blasting that can apply in the high slope of the expressway in the section, and designed the parameter. The practice shows that it gained favourable effect by this method.  相似文献   

Application of Function Analysis in Conceptual Design     

DENG Lin  ZAN Xin wu  HUANG Mao lin  LIU Wei 《保鲜与加工》2002,(12):4-6

Product design is a procedure that enterprises meet the needs of consumers; conceptive design is one of the steps in product design and it directly considers requirements of consumers. So how to supply consumers with satisfying function is the essential point. On the basis of function analysis of Value Engineering, the paper puts forward a new method to exercise function definition and function analysis, implements conceptual product design procedure with database techniques.A new way is gotten to convert requirements to conceptual product.  相似文献   

New Method of Founding Profile Equations and Pressure Angle Formula to the Cylindrical Cam Mechanism with Slide Roller-Follower     

NIU Zhi hong  HE Yu lin 《保鲜与加工》2002,(6):23-26

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