• Volume 25,Issue 4,2002 Table of Contents
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    • Research on Independent Product Development for Concurrent Collaborative Environment & Supporting Technologies

      2002, 25(4):1-5. DOI: 10.11835/j.issn.1000-582X.2002.04.001

      Abstract (746) HTML (0) PDF 447.99 K (972) Comment (0) Favorites

      Abstract:This article deals with the research on the features and collaborative process of independent development of key automobile parts. It generally employed concurrent engineering theory and technologies of Internet & Intranet, computer aided design (CAD), computer aided manufacturing (CAM) and product data management (PDM). Field knowledge on independent development of key automobile parts was concluded and a set of concurrent collaborative environment and key enabling supporting technologies that face the independent development of automobile body panel dies were also built up. Meanwhile it introduced the secondary development methods of knowledge based engineering (KBE) to implement the knowledge transformation of designing and manufacturing experiences for an enterprise. The results was applied for the development & production of one of this enterprise's new automobile styles and work well.

    • Virtual Multi-channel Instrument of Temperature Measurement

      2002, 25(4):6-10. DOI: 10.11835/j.issn.1000-582X.2002.04.002

      Abstract (967) HTML (0) PDF 440.99 K (1979) Comment (0) Favorites

      Abstract:介绍了温度测试的现状和新兴的虚拟仪器技术,探讨了将虚拟仪器技术应用于温度测试领域的方法,结合实例分别对虚拟式多通道温度测试仪的主控模块,通道设置模块,数据采集模块,分析模块,显示模块,存储模块以及其他辅助功能的设计和实现做了详细说明,实验表明本虚拟式温度测试仪测温响应时间短,测温范围宽、选择合适的传感器,可实现0-1000℃范围内测温,测温精度较高,既能实现在线分析又能实现离线处理,展示了虚拟仪器强大的生命力和温度测试的新方法,还展望了虚拟式温度测试仪的美好前景。

    • Design of the Virtual Instrument of Frequency/Amplitude Sweep

      2002, 25(4):11-14. DOI: 10.11835/j.issn.1000-582X.2002.04.003

      Abstract (747) HTML (0) PDF 383.50 K (1436) Comment (0) Favorites

      Abstract:The virtual F/A sweep instrument appears as a new instrument when the F/A weep technology using widely but the traditional hardware-oriented F/A sweep instrument couldn't meet the demand. The instrument not only overcomes the shortcomings of the traditional hardware instrument, but also have the advantages of powerful functions, small solidity and easy operation, which make test accurately, fast and simply. This paper introduces the principle, features and operating method of F/A sweep instrument. The designing idea and realizing methods of the virtual F/A sweep instrument are discussed in detail from 3 ways, which include hardware, software and panel. Two applied examples of virtual F/A sweep instrument are given. The virtual F/A sweep instrument has already been used in actual applications.

    • Power Model of Bond Graph and Dynamic Simulation of Hoist System for Multi-Flow Transmission

      2002, 25(4):15. DOI: 10.11835/j.issn.1000-582X.2002.04.004

      Abstract (922) HTML (0) PDF 343.94 K (1030) Comment (0) Favorites

      Abstract:The double drive hoist reducer developed in the planetary gear is a new generation of energy saving and environment protecting hoist product. The multi flow transmission system theory of hoist is analyzed. With the theory and method of bond graph,a bond graph model with coupled vibration is established for hoist multi flow transmission system for the first time. The state equation of the system is developed and dynamic simulation analysis is also carried out. The internal changing law and relationship of the system for the state variable are got. Therefore, the dynamic properties and gearing features of this system are revealed comprehensively. The research results can provide the dynamic analysis method and design basis for multi flow transmission system of hoist.

    • Microcomputer Controlled Resistance Welding Power Source

      2002, 25(4):19-21. DOI: 10.11835/j.issn.1000-582X.2002.04.005

      Abstract (612) HTML (0) PDF 269.14 K (1290) Comment (0) Favorites

      Abstract:A new tape resistance welding power source based on 80C196KC single-chip microcomputer was developed.The MOSFET group worked at linear state was used as current adjuster.Arbitrary control of current waveform was achieved first in the moment of resistance welding.So that it is possible to weld with optimal current waveform in resistance welding.The power source was used in the welding of bridge band,that solved the problem occurred at traditional welding means,and met the strict requirement of the welding quality of bridge band.The practice shows that it is an ideal power source in the precise welding of minisize metallic workpiece.

    • Analysis on Stability for Uncertainty Complex Control System Based on Knowledge

      2002, 25(4):22-25. DOI: 10.11835/j.issn.1000-582X.2002.04.006

      Abstract (729) HTML (0) PDF 342.64 K (1267) Comment (0) Favorites

      Abstract:Concept of stability is vague, but it is basic characteristic of dynamic system, and precondition that make all kinds of control system run normally. Today it is still a challenge to analyze stability for uncertainty complex control system, whose mathematic modeling is impossible or very difficult, so it is very hard to judge whether a system running is stable or not by mathematic stability criterion. A kind of analyzing method is presented, which combine absolute stability with self-locked concept of heuristic search, it may analyze system stability in more range through adjusting self-collected loop parameters for uncertain control system based on knowledge control model. It is shown that stability analyzing method is effective and suitable for practical physical system in the engineering project.

    • Effect of Nano-Al2O3 on the Properties of Ultra High MolecularWeight Polyethylene Engineering Material

      2002, 25(4):26-28. DOI: 10.11835/j.issn.1000-582X.2002.04.007

      Abstract (730) HTML (0) PDF 256.16 K (1201) Comment (0) Favorites

      Abstract:The composite material of nano-Al 2O 3 and UHMW-PE was made by the way of pressing and agglomeration. Effect of nano-Al 2O 3 on the friction, wear characteristic of Ultra High Molecular Weight Polyethylene plastic was studied by using MPV-200 model friction and wear tester and caustic wear one. At the same time, the hardness of UHMW-PE was mensurated in sclerometer. The results showed that nano-Al 2O 3 not only decreases the friction coefficient of UHMW-PE, but also greatly reduce the wear of UHMW-PE.The hardness of UHMW-PE is improved. Which possesses important theoretic significance for optimizing of structure and property of UHMW-PE material.

    • Solid Model Design on the Features of Products

      2002, 25(4):29. DOI: 10.11835/j.issn.1000-582X.2002.04.008

      Abstract (724) HTML (0) PDF 375.15 K (1398) Comment (0) Favorites

      Abstract:To research the problem of plastic art design and emulation of products with the virtual reality technology can short the product development cycle and reduce the cost. This paper discusses the information based on the product feature ,solid model with parameters, the structure and function of this system. Combined the product properties with its solid model. Proposed a method with CAD to create the model of the product based on features in the product design. Expressed its feature parameter and shape of model fully .In the case for a deceleration box the feature model has solved the problem of physical information ,geometry information and the informative process in its production management system efficiently.

    • Research on Cooperative Design Network Security Based on IP-VPN

      2002, 25(4):32-35. DOI: 10.11835/j.issn.1000-582X.2002.04.009

      Abstract (581) HTML (0) PDF 346.28 K (1256) Comment (0) Favorites

      Abstract: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.

    • Surface Charge Distribution and Tip Electric Field about Carbon Nanotubes

      2002, 25(4):36. DOI: 10.11835/j.issn.1000-582X.2002.04.010

      Abstract (1002) HTML (0) PDF 274.76 K (304) Comment (0) Favorites

      Abstract:Carbon nanotubes(CNTs) have some special physic properties which may own important technical values. We studied the electric characteristics of metallic carbon nanotubes including potential distribution, surface charge distribution and tip electric field based on electromagnetic theory. Our results show that the relative values of tip charge densities of short CNTs are bigger and so are the absolute values for long CNTs. We also find the electric field at the tips of metallic nanotubes is much bigger than external electric field. This is helpful for exploring theoretical problems about CNTs' field emission.

    • Human Face Location Based on Motion Information in a Complex Background

      2002, 25(4):39-42. DOI: 10.11835/j.issn.1000-582X.2002.04.011

      Abstract (653) HTML (0) PDF 349.52 K (147) Comment (0) Favorites

      Abstract:This paper proposes an improvement for the traditional Optical Algorithm, and presents a new way to image segmentation in a complex background. In addition, combined with the neural network, the system can locate the possible human faces successfully by means of two-step location model. In our system, the searching and locating of the human face is the most important stage. According to this, the authors adopt the two-step way to run, firstly they take up the segmentation of the candidate human face areas and then the accurate face locating based on the neural network is used. This algorithm is fast and robust. Experimental results with real scene images are given out there, and all these prove that two-step method gains many advantages in the course of human face location with motion information, such as real-time, robustness and practicality. In addition, the proposed system is also the fundamental and important part of the perfect human face recognition system.

    • Exact Integration of Biharmonic Equation In Boundary Element Method

      2002, 25(4):43-46. DOI: 10.11835/j.issn.1000-582X.2002.04.012

      Abstract (599) HTML (0) PDF 243.88 K (116) Comment (0) Favorites

      Abstract:The boundary integral in Boundary Element Method effects the precision and the speed of the method. The boundary integrals are composed of the normal integrals and singular integrals. The normal integrals are popularly calculated by exact integral, and the singular integrals by the Gauss numerical integral. The singular integrals are low in precision when the source points approach the element. This paper presents an alternative way to transform the double integral in Biharmonic Equation on 3-d into the linear integrals on the boundary of each subdomain, so that all the singular integrals and nonsingular integrals are calculated by analytical method. It makes the precision and the speed of BEM improve.

    • Optimality Conditions for Nonsmooth Extremum Problems in Topological Vector Spaces

      2002, 25(4):47. DOI: 10.11835/j.issn.1000-582X.2002.04.013

      Abstract (854) HTML (0) PDF 335.57 K (127) Comment (0) Favorites

      Abstract:Some new concepts of coneD_s convexity,coneD-s quasiconvexity,cone D-s pseudoconvexity,s right derivative of vector value mapping are proposed;and their related properties are discussed;the optimality necessary conditions and sufficient conditions for constrained extremum problem(VP)involving in cone D-s convex mapping are extablished;the relation between local optimal solution and global optimal solution;as well as the relation between weakly efficient solution and efficient solution for (VP) are derived;the corresponding results generalize the related results of classic convex programming.

    • Model of Information Integrating in CIMS Based on the Object-oriented Method

      2002, 25(4):51-54. DOI: 10.11835/j.issn.1000-582X.2002.04.014

      Abstract (715) HTML (0) PDF 361.86 K (155) Comment (0) Favorites

      Abstract:Information integrating is the most important key to CIMS,which is the base of the function integrating and all others.Because of so many kinds,so complicated structure,so many different sources and uses that the information in CIMS has,it is necessary to build a popular Information Integrating Model. The model of information integrating in the thesis bases on the enterprise model,which is presented by ISO(International Organization for Standardization).According to the object-oriented method,the process of modeling begins with classifying the information,and then describes the definition of the attributes and the structural relation of those objects. By means of the idea of Encapsulation and Inheritance,the destination of information integrating can be arrive and the model of information integrating can be set up. The model which is based on the share information is helpful to finish the function integrating and the whole CIMS' construction. Moreover,the system which is developed following such program can be reused for many times and the developing circle of CIMS can be apparently shortened,too.

    • A Fuzzy Controller with Simulating Human Intelligent Control and Its Simulation Analysis

      2002, 25(4):55-60. DOI: 10.11835/j.issn.1000-582X.2002.04.015

      Abstract (750) HTML (0) PDF 452.09 K (221) Comment (0) Favorites

      Abstract:In the intelligent control system with microprocessor controlling, the development of embedded software requires some simple and practical intelligent control algorithms. The algorithms can not only make the control system's performance good, but also meet the demands of real time control. Aim at the problem, it is presented that a fuzzy controller with simulating human intelligent control. The structure , control algorithms and the simulation results of the controller are given. The simulation and application show that the fuzzy controller with simulating human intelligent control has many advantages such as fast response, less overshoot, good robust. The design of the controller does not need the accuracy math model of controlled object.

    • A Vector Quantification Image Coding Scheme Based on Wavelet Transform

      2002, 25(4):61-64. DOI: 10.11835/j.issn.1000-582X.2002.04.016

      Abstract (655) HTML (0) PDF 365.92 K (158) Comment (0) Favorites

      Abstract:The paper proposes an image compression and coding scheme based on discrete wavelet transform (DWT), which makes the best of the relativities among original image and coefficients of wavelet, the relativities among pixels of subimages, the relativities among directions of subimages. Human visual specialities were considered, so the compression scheme leads up to make full use of the statistical redundancy and visual redundancy of image. To get high compression ratio and good quality of image, the coefficients of image working on the quality of image greatly were reserved accurately, but the coefficients of image working on the quality of image slightly were quantified roughly. Also, the regrouping and coding of the coefficients could be used universally. The experimental results show that the compression method is provided with simply calculating, little time for coding and decoding and satisfying quality companied with high compression ratio.

    • Improvement Methods of Fuzzy Control with Intelligent Integration

      2002, 25(4):65-67. DOI: 10.11835/j.issn.1000-582X.2002.04.017

      Abstract (722) HTML (0) PDF 228.27 K (168) Comment (0) Favorites

      Abstract:Fuzzy controller can achieve satisfactory dynamic performance even for complicated process without mathematical model of the process.Its main imperfection is the existence of steady state error and ultimate oscillatory in the process output. This limits its application area. How to eliminate the steady state error while keep its good dynamic performance has been paid much attention. The strategy to introduce integral function to the conventional fuzzy control system is put forward in this paper to overcome the above problem. After expound two key factors on introducing integral action,an intelligent integral algorithm has been employed,and two methods on introduction of the intelligent integral to the fuzzy control system are proposed. Their characteristics and applied situations are summarized.

    • Dynamic Route Guidance System Based on Genetic Algorithm

      2002, 25(4):68-71. DOI: 10.11835/j.issn.1000-582X.2002.04.018

      Abstract (842) HTML (0) PDF 337.11 K (235) Comment (0) Favorites

      Abstract:The study on Dynamic Route Guidance System (DRGS) is an important research in the field of Intelligent Transportation System(ITS),which guide the behaviors of travelers by providing them with optimal route based on real-time traffic information. As a result the travel time can be saved and the traffic congestion can be avoided. The route guidance algorithm can compute the best route between the begin point and destination. The globe near best property and real-time property must be considered , the Genetic Algorithm have qualifications for globe optimal and parallel algorithm. Genetic algorithm(GA),for solving the shortest route,is proposed in this thesis?The ordered real code rule,crossover,mutation are given. The efficiency of the GA is proved through an example.

    • Catalog Tree Algorithm and Its Application on Universal Archive Management System

      2002, 25(4):72-75. DOI: 10.11835/j.issn.1000-582X.2002.04.019

      Abstract (700) HTML (0) PDF 281.25 K (123) Comment (0) Favorites

      Abstract:Archive management system is an important content of MIS(Management Information System). Because there are detailed catalog standard in the field of archive management,and users want to modify the definition of classification in the system themselves to meet the requirement of universality, this article introduces a catalog tree algorithm based on database. That is to generate a good defined catalog tree which locates on the kernel of the whole system. Proper maintenance is applied when catalog standard is changed. This proposal has already been put into use on the archive of a petrifaction enterprise and proved to be feasible.

    • The Effect Factor of Surface Tension of Liquid/Vapor in Molecular Dynamics Simulation

      2002, 25(4):76-78. DOI: 10.11835/j.issn.1000-582X.2002.04.020

      Abstract (826) HTML (0) PDF 226.21 K (1380) Comment (0) Favorites

      Abstract:用分子动力学模拟方法研究汽液界面性质时,适当选取模拟分子数目和势函数截断半径,既能满足合理的计算时间要求,又减少分子数目效应和势函数截断半径对计算结果的影响,在NVT系综中,以氩原子为对象,对长方形模拟盒中粒中数目为500、864、1372和2048个的汔液平衡系统进行模拟计算,在计算时发现,汔液界面的表达张力值与模拟分子数目有关,模拟分子数目在1000个以上,表面张力值趋于恒定,势函数截断半径Rc=4.5σ,计算结果与实验值吻合较好。

    • Brief Study on Physiological Effects of Sound Field on Actinidia Chinensis Callus

      2002, 25(4):79-83. DOI: 10.11835/j.issn.1000-582X.2002.04.021

      Abstract (531) HTML (0) PDF 475.85 K (1021) Comment (0) Favorites

      Abstract:Insight into the relationship between plant cell (tissue) and physical stimulation is a focus of biomechanics. In this study, several important plant physiological indexes of Actinidia chinensis callus in sound field including the content of soluble proteins, the activity of SOD, the activity of IAA oxidase and the penetrability of cell membrane, were measured. Some information is got about stress effect through the study and try to explore its mechanism. From the result of experiment,we found that there were a great similarity of stress effect on sound field between Actinidia chinensis and Gerbera Jamesonii acrocarpous , a kind of herbage plant, which had been studied in our lab before. That is to say, the sound field also has dual effect on woody plant. It can enhance or inhibit the growth and development of Actinidia chinensis callus along with the sound field frequency ,and the moderate frequency of sound field acting on the callus could promote callus growth. A conclusion is drawn that the optimal stimulation of sound field are 100 dB and 1 000 Hz. Under the conditions, the sound field can distinctly enhance the growth of Actinidia chinensis callus Whereas, it is not very easy to explore the detail mechanism of environmental stress effects on plant. This paper discussed the mechanism of sound field stress on plant from the level of cell and molecule.

    • Hemodynamic Effect of Polymyxin B Sulfate on Rats with Endotoxemia

      2002, 25(4):84-86. DOI: 10.11835/j.issn.1000-582X.2002.04.022

      Abstract (742) HTML (0) PDF 289.99 K (1218) Comment (0) Favorites

      Abstract:观察多粘菌素B(PMX-B)对内毒素血症大鼠血流动力学的影响,并进行了实验,实验分为:内毒素(LPS)+多粘菌素B组、LPS+生理盐水组、LPS模型组,给大鼠一次性静脉注射内毒素(0.5mg/kg),前2组分别注入内毒素后0.5h静脉给予多粘菌素B(0.2mg/kg)和1mL生理盐水(NS)、LPS模型组大鼠注入内毒素后不作其它处理,给多粘菌素B后0.5、1、2、4h抽血液,检测血浆中LPS、肿瘤坏死因子(TNF-α)、全血粘度(WBV)、血球压积(HRC)的变化。结果表明:LPS+多粘菌素B组,在给内毒素1h,全血粘度、红细胞压积明显低于LPS+生理盐水组。因此多粘菌素B治疗能改善内毒素血症早期的血液流变性。

    • Application of the Weibull Distribution for the Recognition of Transformer PD Phenomena

      2002, 25(4):87-90. DOI: 10.11835/j.issn.1000-582X.2002.04.023

      Abstract (713) HTML (0) PDF 351.46 K (760) Comment (0) Favorites

      Abstract:The problem of identification of partial discharge phenomena occurring in a transformer insulating system is addressed. Under the assumption that different PD sources can produce pulse of different PD distributions, five typical artificial defects have been designed to compare the PD distributions coming from different sources, such as internal voids, surface and corona discharges. In this aim, Weibull distribution has been introduced to estimate the parameters and the least square methods (LSM) have been used to estimate the parameters. The goodness of fit to a Weibull distribution is checked by the Cramer-von-Mises (CVM) test. It is shown that the probability function fits well the partial discharge height distribution. By this way,different discharge sources can be distinguished. by Weibull parameter. In addition, the recognition of two or more PD phenomena simultaneously active is approached by means of an additive Weibull distribution. It allows quantities related to each of the two or more superimposed PD phenomena to be estimated, according to the Weibull parameters and the standard mean quantities.

    • A Furry Synthetic Evaluation Model in Capital Structure Decisions

      2002, 25(4):91-94. DOI: 10.11835/j.issn.1000-582X.2002.04.024

      Abstract (735) HTML (0) PDF 342.72 K (995) Comment (0) Favorites

      Abstract:This paper analyzes the limitation of regarding the weighted average cost of capital as the optimal standard of capital structure in the traditional capital structure decision-making method, and analyzes the view that the capital structure is affected by many factors,such as earning power, long-term stability of operating, the attitudes held by owners and operators, the attitudes held by creditors and financial risk. With the example, the affecting factors of the capital structure is analyzed. The fuzzy synthetic evaluation model are employed to decision-making of the capital structure. This article also shows the key point of its application.

    • Transaction Cost During Reform Process of Separation ofNetwork Operations and Generation, and Making Electric Generation Market Competitive in Power Market

      2002, 25(4):95-98. DOI: 10.11835/j.issn.1000-582X.2002.04.025

      Abstract (802) HTML (0) PDF 333.44 K (1334) Comment (0) Favorites

      Abstract:This paper analyzes interior transaction cost before the reform of separation of network operations and generation, and making electric generation market competitive in power industry, and market transaction cost in complete power market with the theory of transaction cost in china on the basis of the actuality and characteristic of Chinese power industry,then the describtion and the scalar comparisim are done between two costs by curve and mathematics. Based on the economic theory,the authors analyze the compare result,and come out the economic term of separation of network operations and generation in power industry, that is to say that there isn't economic reason when the electric plant lies in the phase of scale reward increasing by degrees,on contrast,when the electric plant lies in the phase of scale reward decreasing by degrees,the reform should be done step by step.

    • Evaluation for Enterprise Core Competence Based on AHP

      2002, 25(4):99-102. DOI: 10.11835/j.issn.1000-582X.2002.04.026

      Abstract (1015) HTML (0) PDF 344.45 K (1429) Comment (0) Favorites

      Abstract:Analytic Hierarchy Process(AHP),a qualitative and quantitative method for multi target decision, was first brought up by T.L.Saaty in 1970s. By using AHP, the author establishes a mathematic model of hierarchy relationship among competitive factors, evaluation indexes for performance and level of performance, To analyze influences of each competitive factor on performance and create arrangement of competitive factors in terms of importance to performance of enterprise own or rival firms, and ascertain core competence according to qualitative and quantitative analysis to support competitive decisions in markets. Finally the result of this research is applied to DaFeng Ltd. and its' feasibility and practicality in decision can be tested and verified.

    • Research on the possibility of making DP theory into a model

      2002, 25(4):103-106. DOI: 10.11835/j.issn.1000-582X.2002.04.027

      Abstract (551) HTML (0) PDF 340.05 K (1366) Comment (0) Favorites

      Abstract:This article carries out a study on the possibility of making DP theory into a model from the point of technical development,and makes some further research into this theory. The conclusions include:the necessary condition for applying DP theory is that the surrounding area should have a higher tolerance to the pressure resulting from the development of the Pole. The recognition of this fact requires the government to focus more on the tolerance of the surrounding area rather than the developing effect only. The author also makes a detailed research on the scale limitation of the Pole selection,and finds out there exist positive correlations respectively between the newly_added investment and the dispersing effect,and the polarizing intensity,and the needed time for fulfilling this process.

    • Research on the Forecasting Model of Foreign Exchange Income in Chongqing

      2002, 25(4):107-109125. DOI: 10.11835/j.issn.1000-582X.2002.04.028

      Abstract (549) HTML (0) PDF 356.07 K (816) Comment (0) Favorites

      Abstract:It is very imporfand to monitor the exchange of the foreign trade income when the convertibikty of current account has been realied.In order to enforce the monitoring of the settlement of foreign exchange income in Chongqing, Grey Model and Auto-Regression Model have been built based on the characteristics of local data, which focus on the forecasting of the local settlement of foreign exchange of foreign trade income. From different aspects, these two models efficiently forecast the variation, in short run and middle run, of the exchange of foreign trade income in Chongqing. Based these analyses, this paper suggests the combination of two models and enforcing the monitoring of the settlement of foreign exchange of cooperation of enterprises and banks.

    • A New Dynamic Method for Calculating NPV

      2002, 25(4):110-112. DOI: 10.11835/j.issn.1000-582X.2002.04.029

      Abstract (751) HTML (0) PDF 255.88 K (1163) Comment (0) Favorites

      Abstract:NPV have been widely applied. A majority of the existing calculating methods of cash flow are the static method or the expectation method. It is more reasonable to regard future cash flow as random variable which has certain probability distribution, which shifts with time. But the research about it has been introduced rarely. Through introducing some kinds of existing methods and considering the feature of Markov method, a dynamic method which is used in solved the distributing of indeterminate feature cash flow is showed. So a new kind of dynamic calculation method about NPV is obtained. The method is applied in the calculation to future cash flow of the certain highway investment project of China. The result shows that this method is feasible, effective.

    • The Analyze of Capital Structure and Value of Company

      2002, 25(4):113-115. DOI: 10.11835/j.issn.1000-582X.2002.04.030

      Abstract (845) HTML (0) PDF 271.99 K (132) Comment (0) Favorites

      Abstract:Capital structure of company changes company value in a frictional market environment through cutting down cost and decreasing moral risk and causal problem in trust agency. The authors apply method of asymmetric information game to analyze how to make design of mechanism on the basis of existing revenue and cost of bankruptcy, make the company's manager maximize shareholder's wealth through maximizing own effectiveness, thus define the best radio of liabilities.The authors show that good companies have higher value than difference one in a assured mechanism, afitness capital structure could reduce the problem in trust agency of company's manager,higher risk project can bering more value for compay.

    • Duality and Hyperplanes of Fuzzy Matroids

      2002, 25(4):116-119. DOI: 10.11835/j.issn.1000-582X.2002.04.031

      Abstract (937) HTML (0) PDF 291.03 K (116) Comment (0) Favorites

      Abstract:Fuzzy matroid is a new fuzzy system originated with the introduction of notion `fuzzy' into the theory of matroid. Some characteristics of fuzzy dual matroids are discussed according to the concept of fuzzy dual matroid given by Goetschel R.J and Voxman W., and then the notion of fuzzy hyperplanes is defined and some of the basic properties of them are investigated. Among these properties three necessary and sufficient conditions are provided from different aspects. Application of fuzzy hyperplanes is provided:fuzzy cloed sets always can be stated by the finite fuzzy hyperplanes.

    • A Difficulty of Symmetrical Stress Model

      2002, 25(4):120-121. DOI: 10.11835/j.issn.1000-582X.2002.04.032

      Abstract (734) HTML (0) PDF 168.30 K (106) Comment (0) Favorites

      Abstract:There is mased differences between experimental and analytical results in the frame of symmetric stress model,when the notable stress gradient exist,or outstanding microstructure is to be considerated,or wavelength is too shorter in dynamic problems. Other difficulty is introduced in linear elastic statics of homogeneous isotropic solid that.The problem is that,neighbor boundaries of a angle domain are subjected to two shear forces not equal each other. The problem is not solved in the frame of symmetric stress model. In the frame of the asymmetric stress and couple stress model in present paper this difficulty is sovlved. It is show that,as the distance from the boundaries increase the solving in the frame of asymmetric stress model tent to that in the frame of symmetric stress model.

    • Relation Between the Anghe of Shotput and the Maximum Projetile Range

      2002, 25(4):122-125. DOI: 10.11835/j.issn.1000-582X.2002.04.033

      Abstract (612) HTML (0) PDF 283.51 K (135) Comment (0) Favorites

      Abstract:为了解决铅球适宜投出角度公式与实践偏离的问题 ,采用抛体运动及数学分析的方法探讨了铅球成绩与抛体最大射程的函数关系 ,得出了最大成绩定理、最佳投出角度公式和最佳出手角度标志线参数式 ,从数学上证明了“与手角对应的轨迹角等于 4 5°会有最大投掷成绩”的判断。

    • >工程应用
    • A PACS Scheme Based on High-speed Ethernet

      2002, 25(4):126-129. DOI: 10.11835/j.issn.1000-582X.2002.04.034

      Abstract (623) HTML (0) PDF 354.45 K (191) Comment (0) Favorites

      Abstract:Picture archiving and communication system(PACS) is the key way to realize the medical images modernized management, the main work of which is to ensure the medical image information can be transmited and applied with high efficient. The Ether net is a popular local net. The author has described a PACS scheme based on high speed Ether net, with which, many modular functions (medical image sampling, medical image processing, medical image storage, medical image management, medical image review, medical image transmission, medical image edit, et al) can be realized. Also, the PACS can be fused with HIS.

    • Controlled Rolling, Cooling Process and Optimization of 16MnR Steel

      2002, 25(4):130-133147. DOI: 10.11835/j.issn.1000-582X.2002.04.035

      Abstract (603) HTML (0) PDF 402.89 K (220) Comment (0) Favorites

      Abstract:16Mn钢中加入0.01%钒、钛,1100℃开轧、850℃终轧,分别在奥氏体再结晶区及奥氏体未再结晶区控制轧制,轧后给以3-4℃冷却速度控制冷却,得到的轧件组织细小、带状珠光体明显减少,钢材的各项性能指标均得到了较大的提高。利用MATLAB数据处理软件对轧制工艺参数与材料的性能之间的关系进行了多元线性回归并进行优化,得到的回归公式及优化结果对建立中厚板轧制工艺--组织--性能在线控制专家系统的建立具有重要的指导意义;利用该回归及优化结果,可根据轧制时的基本工艺及轧件的化学成分,预测轧件的性能指标,为轧制工艺参数的实时调整提供重要的依据。

    • Heat-resisting Steel H2 with Ultra-low Sulphur

      2002, 25(4):134-136. DOI: 10.11835/j.issn.1000-582X.2002.04.036

      Abstract (821) HTML (0) PDF 246.12 K (158) Comment (0) Favorites

      Abstract:阐述了元素硫、氧、钙、锶对钢性能的影响,介绍了H2超低硫耐热钢(3Cr25Ni10)化学成分选择的依据。叙述了H2钢的熔炼工艺及其主要性能的测试结果。结果表明H2-2耐热钢(含S<0.001%,Ca0.003%-0.004%)的高温抗氧化性能、高温持久强度和热疲劳性能好于H1钢,远好于H0钢;其生产成本稍低于H1钢,远低于H0钢。性能比较表明H2-2钢完全可以替代H0钢用于制作高温还原罐,预计的使用寿命比H0和H1钢高,且经济效益十分显著。

    • Basic Characteristics and High Temperature Oxidizing Roasting Of The Zinc-oxide Ore

      2002, 25(4):137-140. DOI: 10.11835/j.issn.1000-582X.2002.04.037

      Abstract (994) HTML (0) PDF 318.43 K (180) Comment (0) Favorites

      Abstract:通过对氧化锌矿的矿物组成、熔化温度等基本物性的研究,确定采用高温氧化焙烧的方法对氧化锌矿进行焙烧实验;试验结果表明;在所有的焙烧实验条件下,烧损率的变化并不明显,在30%左右;提高温度,可提高焙烧效果,焙烧的适宜温度为1200℃;增加焙烧时间,其焙烧效果与矿石焙度有关,粒度为5-10mm,焙烧时间为90min的焙烧效果较好,而粒度为15-20mm时,120min的效果较好;增加粒度有利于提高焙烧效果,矿石的适宜粒度为15-20mm。

    • Research on the Sacrifical Anode FC of Magnetie Iron Qxide

      2002, 25(4):141-143. DOI: 10.11835/j.issn.1000-582X.2002.04.038

      Abstract (808) HTML (0) PDF 235.52 K (127) Comment (0) Favorites

      Abstract:论述了磁性氧化铁牺牲阳极生产的必要性、工艺技术条件 (压块压力、烧结温度、烧结时间 )及产品性能等。该阳极的化学成分为 90 %mol (以Fe2 O3 表示 )的Fe3 O4和 10 %molMe1O混合物 ,粒度 <16 μm。研制出的磁性氧化铁牺牲阳极样品结构致密 ,电阻率小 (0 .0 0 7Ω·cm) ,在 2 0 %HCl溶液中腐蚀失重率为 0 .72 % h。结果表明 :采用粉末冶金法生产此种磁性氧化铁牺牲阳极可以做到工艺顺利、牺牲阳极的结构致密、电阻率小、抗腐蚀性能良好。其中以 11# 牺牲阳极的性能为最好。其工艺条件为成型压力 1 2t cm2 ,烧结温度 110 0℃ ,烧结时间 5h。

    • >研究综述
    • Advancement of High Pulsed Electric Field for Inactivation of Microorganism

      2002, 25(4):144-147. DOI: 10.11835/j.issn.1000-582X.2002.04.039

      Abstract (912) HTML (0) PDF 380.63 K (153) Comment (0) Favorites

      Abstract:Inactivation of microorganisms can be realized by the accurately controlling the pulse electric field the strength and time for microorganism cell membrane. Use of high pulsed electric field for inactivation of microorganisms is one of the more promising nonthermal processing methods. Compare with pasteurization,it possesses the advantage of instant and even distribution throughout a conductive food system,short treatment time and very little heating of the medium in continuous processing. In addition, HPEF can decrease the loss of nutrition as little as possible. The author critically review the results of earlier experiment studies on HPEF,the mechanisms of inactivation by HPEF,and we suggest the future work that is required in this field.

    • >研究简报
    • The Studies of Syntheses of Phenylacetyl Isoglutamines Derivatives and their antineoplastic activity

      2002, 25(4):148-150. DOI: 10.11835/j.issn.1000-582X.2002.04.040

      Abstract (817) HTML (0) PDF 251.20 K (1192) Comment (0) Favorites

      Abstract:苯乙酰异谷酰胺作为抗癌酮(Antineoplaston A10)在体内的一种降解产物,具有一定程度的抗肿瘤活性。为此设计并合成了一些新的苯乙酰异谷氨酰胺类化合物以测试其抗肿瘤活性。合成中采用在酸性条件下,先选择性地对L-谷氨酸γ位羧基进行酯化,再进一步合成目标化合物,反应条件温和,收率好。所合成化合物结构经IR、^1HNMR及元素分析鉴定,对所合成的目标化合物的抗肿瘤活性采用MTT法对体外培养的乳腺癌细胞成活率进行了测试,初步结果显示有一定抑制肿瘤细胞存活的作用。


Volume 25, No. 4

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