Volume 23,Issue 5,2000 Table of Contents

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  • 1  Profile Precision of Hypoid Gears Controlled by Coordinate Measurements
    YANG Hong cheng QIN Da tong LIU Heng xue
    2000, 23(5):1. DOI: 10.11835/j.issn.1000-582X.2000.05.001
    [Abstract](547) [HTML](0) [PDF 260.38 K](845)
    Abstract:
    The geometrical model of profile error is put forward to describe the tooth surface precision of hypoid gears. The influence of each machine tool setting error on profile error is investigated respectively, and the research of the associativity and compensativity among the machine tool errors are made. The setting errors of machine tool, the optimal modifying parameters and their value are got from the measurement coordinates of hypoid gear real tooth surface, and the adjusted manufacturing shows the geometrical precision of the tooth surface is improved effectively.
    2  Effects of Wave Speed on Frequencies of the Self excited Oscillation Pulsed Abrasive Water Jets
    YANG Lin LI Xiao hong WANG Jian sheng LU Yi yu
    2000, 23(5):4. DOI: 10.11835/j.issn.1000-582X.2000.05.002
    [Abstract](666) [HTML](0) [PDF 333.03 K](913)
    Abstract:
    The effects of cavitation and abrasive acceleration in the self excited oscillation pulsed abrasive water jets are directly determined by its oscillating frequencies, so the wave speed in the jets and its effects on pulsed frequencies are discussed. The numerical results show that the oscillating frequencies of the jets increase obviously with decreasing wave speed, and the abrasive parameters have almost no effects on the wave speed, whereas the exit of air in fluid has significant consequences on the wave speed.It was found that these conclusions were applicable for design the nozzle of the jets.
    3  Recent Development of Nanocrystalline and It''''s Mechanical Machining Technology
    ZHAN Jie CHEN xiao an MENG Jian jun
    2000, 23(5):8-11. DOI: 10.11835/j.issn.1000-582X.2000.05.003
    [Abstract](580) [HTML](0) [PDF 375.76 K](189)
    Abstract:
    Nanocrystalline materials is a new area in materials science, because it possesses some special functions in sound, light, electric, magnet and heat and advance performances. This paper reviews the recent developments of nanocrystalline materials, describes in details its manufacturing methods and studies initially its forming and machining technologies.
    4  Research & Operation on Mathematical Methods used in NC System of Profile followed Grinding Robot
    CHEN Guo Cong YANG Zheng Shu
    2000, 23(5):12-16. DOI: 10.11835/j.issn.1000-582X.2000.05.004
    [Abstract](627) [HTML](0) [PDF 340.71 K](204)
    Abstract:
    Several mathematic methods used in the numerical control system of profile followed grinding robot are described. Cubic parametric Spline surface function is employed to fit the geometric model of the surface grinded with high precision. Improvement of the physics performance of blade is obtained by reconstructing the large size surface of turbine blade based on calculation geometry. Graphic linear transfer technique is provided to users with unique format of programming. Graphic non linear transfer technique is used to solve some more difficult problems successfully including transformation of the coordinates of comtrolled points in multicoordinates system, adjustment of the attitude of grinding head as well as realization of constant pressure grinding. All these mathematics methods are demonstrated feasible and efficient in actual practice and are valuable in developing large size surface grinding robots.
    5  Automatically Assembly Sequence Planning Based On Genetic Algorithms
    LIAO Xiao yun CHEN Xiang feng
    2000, 23(5):17-20. DOI: 10.11835/j.issn.1000-582X.2000.05.005
    [Abstract](748) [HTML](0) [PDF 261.91 K](105)
    Abstract:
    A modified genetic algorithm for automatically assembly sequence planning is presented in this paper. The assembly direction sets of parts in structure are built to evaluate a assembly sequence without collisions. Five genetic operators are proposed. The fitness of sequence is calculated by its reorientation number, and a fitness scaling scheme is used to overcome premature termination. Example is provided to demonstrate the performance of this algorithm.
    6  Dynamic FEM Analysis of Automobile and Software Development
    HU Yu mei LI Xiao hong CHEN Wei HUANG Xiao he
    2000, 23(5):21-24. DOI: 10.11835/j.issn.1000-582X.2000.05.006
    [Abstract](569) [HTML](0) [PDF 223.93 K](118)
    Abstract:
    In this article, modal analysis technology about dynamic analysis was studied. Free interface model comprehensive method was used to dynamic analysis and design of automobile structure based on theory background of model analysis, test technology conditions, data reliability and precision. In order to test the efficient and possibility of the method, main vibration features about space double layer has been calculated based on this method, comparing this with the precise solution of finite element method, the result shows that this method is suitable not only for simple interfaces between components but also for high reductive interfaces. In addition, the method also has high comprehensive precision. Furthermore it creates conditions to dynamic analysis in automobile structures.
    7  Control Strategy for Asychronized Turbogenerators
    LI Xiao-yan LIAO Yong YANG Shun-chang
    2000, 23(5):25-28. DOI: 10.11835/j.issn.1000-582X.2000.05.007
    [Abstract](615) [HTML](0) [PDF 254.56 K](112)
    Abstract:
    Asynchronized Generator can better solve the excessive reactive and stability problem in power system.In order to improve the dynamic and transient performances of an asynchronized turbogenerator(ASTG),excitation control equation of it in the dynamic synchronous reference frame is presented.Control results are simulated in the synchronous and dynamic synchronous reference frames for ASTG.It is shown that the dynamic and transient performances in the dynamic synchronous reference frame are better than those in the synchronous reference frame.Consequently,the control strategy of dynamic synchronous reference frame can shorten more time on the dynamic process of ASTG.
    8  Single-end Flyback High-frequency High-voltage Switching Power Supplies
    GAO Zeng hui YU Xiang xu
    2000, 23(5):29-31. DOI: 10.11835/j.issn.1000-582X.2000.05.008
    [Abstract](818) [HTML](0) [PDF 183.85 K](166)
    Abstract:
    Based on the research of a practical project of high frequency high voltage switching power supplies,the system design and experimental investigation of a single end flyback high frequency high voltage switching power supply are presented. In order to solve the problem of durable voltage of power MOSFETs that are used in the single end flyback high voltage switching power supply,an effective approach that adopts dual MOSFETs in series connected is proposed.The procedure of the designing and the parameter of each device is given in detail.A prototype of 220 Volt input and 2000V/3mA output is developed, and the validity of the scheme is demonstrated by the experiment.
    9  Effects of Interstage Annealing on the Mechanical Properties and Rolling Performances of AA1235 Aluminum Foils
    FENG Yun-xiang ZHANG Jing PAN Fu-sheng TANG Ai-tao CHEN Jian
    2000, 23(5):32-35. DOI: 10.11835/j.issn.1000-582X.2000.05.009
    [Abstract](844) [HTML](0) [PDF 259.49 K](127)
    Abstract:
    采用 4种不同的中间退火工艺 ,通过显微组织观察、定量金相、X ray衍射分析 ,力学性能测试等实验手段 ,研究了中间退火工艺对AA12 35合金铝箔轧制性能和力学性能的影响。结果表明 ,中间退火工艺对铝箔力学性能和轧制性能有显著影响 ,当采用 380℃× 6h +2 10℃× 9h的分级退火工艺时 ,各压下量下材料的抗拉强度均小于 16 0N/mm2 ,其变形抗力较小 ,塑性较好 ,有利于薄箔的轧制 ,铝箔产品的成品率可达到 80 %以上。显微组织观察表明 ,采用该工艺时 ,铝箔毛料有较好的显微组织 ,Si和Fe析出充分 ,化合物尺寸峰值在 2~ 3μm之间。作者对工艺参数和杂质元素的影响机理进行了分析和讨论。
    10  Reduction of Titanium Oxide and Thickening of Blast Furnace Slag Bearing Higher Titania
    WAN Xin PEI He nian BAI Chen guang ZHOU Pei tu
    2000, 23(5):36. DOI: 10.11835/j.issn.1000-582X.2000.05.010
    [Abstract](991) [HTML](0) [PDF 291.42 K](144)
    Abstract:
    The slag samples that have some titanium oxide reduction grade are reduced with blast furnace slag taken from Pan Zhi Hua Iron & Steel (Group) Co. in site. Then the viscosity and free running temperature of slag samples were measured in laboratory. With the increasing of reduction grade the viscosity and free running temperature of slags would have rising tendency. The mineral structure of the samples is observed in optical microscope, and quantitative analysis of TiC, TiN in the slag samples is made with image analysiser. The results show that the thickening of titanium slag has relationship with the amount of TiC, TiN, which was reduced from titania. So the usage of titanium oxide reduction grade as the index of thickening in blast furnace process is reasonable, and which could represent characteristic of the blast furnace smelting iron ore bearing titanium and vanadium.
    11  Numerical Computation of 3-D Laminar Boundary Layer Equations of Natural Convection Heat Transfer
    ZHU Guang jun LIU Cheng quan
    2000, 23(5):40-43. DOI: 10.11835/j.issn.1000-582X.2000.05.011
    [Abstract](734) [HTML](0) [PDF 228.24 K](112)
    Abstract:
    Coordinate transformation and Box method already succeed in solving boundary layer equations of compelling convection heat transfer,but the solution of natural convection heat transfer has not been informed.For examining the compute accuracy of solving natural convection heat transfer by using this method,this paper numerically computes 3 D laminar boundary layer equations of natural convection heat transfer of stand strip by using this method,the computational results agree with the experimental data from the published paper.The results shows that using this method to solve the equations is feasible.
    12  The Index System for Assessment of Resconstructed Image
    ZHU Bing lian CAO Chang xiu
    2000, 23(5):44-48. DOI: 10.11835/j.issn.1000-582X.2000.05.012
    [Abstract](572) [HTML](0) [PDF 334.73 K](130)
    Abstract:
    迄今为止,压缩重构图象的质量评价还没有统一的标准。通用使用的峰-峰信噪比或均方误差与主观感觉并不相符,而主观评价又存在主观性和不确定性,其结果往往因人而异。笔者根据人眼视觉特征研究了具有视觉心理特点和压缩重构图象质量的评价指标体系,提出了Ce、De、Be评价指标,较好地表述了重构图象的质量,且容易理解。
    13  Belief Network Classifier
    XING Yong kang SHEN Yi dong
    2000, 23(5):49. DOI: 10.11835/j.issn.1000-582X.2000.05.013
    [Abstract](679) [HTML](0) [PDF 353.76 K](1102)
    Abstract:
    Classification is an important research area in Artificial Intelligence, which has a broad range of applications such as pattern recognition, diagnosis, data mining, and so on. A best classifier can be built by using belief networks. This paper mainly discusses how to build the Naive Bayes classifiers, the Augmented Naive Bayes classifiers, and the General Belief Network classifiers. Their respective advantages and shortcomings also be shown by a detailed comparison.
    14  Cell Loss Analysis Based ATM Networks of On-Off Traffic Source
    LI Bo ZHU Qing sheng
    2000, 23(5):53-56. DOI: 10.11835/j.issn.1000-582X.2000.05.014
    [Abstract](621) [HTML](0) [PDF 269.34 K](760)
    Abstract:
    Cell loss, which occurs when buffers overflow in ATM switches, is a key measure for the performance of an ATM network .An ATM network must be designed for very low and predictable cell loss probabilities to provide adequate quality of service for all users. Many methods have been proposed for allocating bandwidth and determining buffer size requirements to provide quality of service guarantees. These methods are subject to overly optimistic allocations or overly pessimistic allocations. The authors present an exact analysis of cell for on off traffic source which can be used in concert with probabilistic methods to ensure that buffer and bandwidth allocation are mode between the best case and worst case requirements.
    15  A Method for Getting Directional Image from Fingerprint Based on Directional Elemental Pixel Sets
    HUANG Xi yue MA Xiao xiao WANG Peng SHEN Zhi xi ZHOU Xin
    2000, 23(5):57-61. DOI: 10.11835/j.issn.1000-582X.2000.05.015
    [Abstract](946) [HTML](0) [PDF 342.74 K](1366)
    Abstract:
    By the definition and interpretation of directional elemental pixel sets, a method for getting the directional image from the binary fingerprint image using the statistic characteristics of DEPS is presented in this paper. This method is better than traditional methods in processing speed, computing complexity and resisting noises. The directional image got by this method is used to the matching of ridges frame in a fingerprint verification system, and the testing result shows that the method is effective.
    16  Developing Real Time 3D Applications with OpenGL
    XU Shou rong
    2000, 23(5):62-66. DOI: 10.11835/j.issn.1000-582X.2000.05.016
    [Abstract](777) [HTML](0) [PDF 388.93 K](1047)
    Abstract:
    D computer graphics technology has progressed to the real time stage. One of the most attracting topics today is how to effectively develop real time 3D systems. The author of this paper has experienced developing some OpenGL based application softwares, and has summarized lots of key techniques including initializing methods, modeling in classes and groups, textures usage, real time viewing control by users and viewing position processing. All these are successfully adapted in the implementation of such systems as real time special effect TV title system and visual road design and evaluation system. In order to be a reference to other researchers and developers, and to make progress together with our competitors, a methodical description is presented here to summarize some typical steps, methods and some valuable experiences.
    17  Study of Drawing and Recognizing Particle Appearance
    LI Yi XIE Li li WANG Ming fu YANG Xi SONG Yang
    2000, 23(5):67-69. DOI: 10.11835/j.issn.1000-582X.2000.05.017
    [Abstract](759) [HTML](0) [PDF 208.23 K](1136)
    Abstract:
    在微粒测试中,粉体颗粒的形貌是一个比较难提取的特征,但它对颗粒粒度分析的结果却影响很大。笔者提出一个适用于显微镜进行颗粒形貌特征提取与识别的方法和指标-形状指数。通过该指标,可以识别颗粒的形状类型,从而对统计颗粒投影区域的形状以及形状的离散程度提供了重要的依据。笔者叙述了形状指数的定义及计算方法,并给出了形状指数与形状类型的关系简表及应用实例。
    18  New Technology of Depolymerising Waste PET
    JIANG Tao YANG Guang WU Li mei
    2000, 23(5):70-73. DOI: 10.11835/j.issn.1000-582X.2000.05.018
    [Abstract](656) [HTML](0) [PDF 284.18 K](1725)
    Abstract:
    以乙二醇和路易斯碱为反应介质的醇碱联合分解废聚酯(PET)技术,可实现常压、180℃、30min内快速、彻底解聚PET,并通过简单工艺即可回收TPA及EG。其分解率≥99%,回收率分别达到98%和96%,产品质量达到相应的国家标准。研究表明该体系解聚速度和分解率受反应温度、废PET比表面、NaHCO3过量程度等因素的影响。实验得出的主要解聚工艺控制参数为:反应温度<186℃、废PET片粒≤3mm、NaHCO3过量程度≥3%、180-186℃下反应时间15-60min。
    19  Research on Mechanism of Depolymerizing Waster PET by Uniting the Ethandiol and the Luis Alkali
    YANG Guang JIANG Tao WU Li mei Research Ctr. Resource Comp.Util.Engr. Chongqing University Chongqing China
    2000, 23(5):74-77. DOI: 10.11835/j.issn.1000-582X.2000.05.019
    [Abstract](755) [HTML](0) [PDF 269.93 K](1082)
    Abstract:
    指出PET在EG和路易斯碱同时存在下,PET的解聚反应是醇解反应与碱解反应相互协同、互为促进的过程,其解聚速度与解聚率得到显著提高,解聚及回收TPA、EG工艺条件简化。实验表明在常压、180℃、30min内,PET解聚率可达99%,其解聚产物的颜色深浅主要受体系碱度、反应温度和反应时间的影响,通过选择不同的路易斯碱、调整解聚工艺条件可有效控制有色物质的生成总量。
    20  Study on Adsorption Characteristics of Coal to Gas in Geophysical Field
    LIU Bao xian XIAN Xue fu XU Long jun LI Xiu qing
    2000, 23(5):78-81. DOI: 10.11835/j.issn.1000-582X.2000.05.020
    [Abstract](755) [HTML](0) [PDF 264.54 K](1390)
    Abstract:
    It is very important to mine safe exploitation, gas drawing and predict of coal and gas outburst that adsorption characteristics of coal to gas in geophysical field are studied. Adsorption and desorption characteristics of coal to gas in geophysical field have been reviewed in detail, then it is obtained that adsorption characteristics of coal to gas in electromagnetic field should be further studied . Adsorption and desorption characteristics of coal to methane in alternating electric field (AEF) have been studied mainly. Adsorption characteristics of three coal samples in AEF have been studied by means of Volume Method. The result shows that chemical properties and matter constituent of coal surface are no changed , adsorption and desorption of the coal samples in AEF well accord with Langmuir equation and two constants empirical formula, and because coal potential energy is increased and coal temperature is raised caused by Joule heat effect , adsorption ability of coal is decreased, and the desorption process is slowed down in AEF.
    21  Numerical Analysis of Impact Response of Cancellous Bone in Human Tibia
    LI De yuan YAO Guo wen LIU Zhan fang ZHANG Xiang wei
    2000, 23(5):82-86. DOI: 10.11835/j.issn.1000-582X.2000.05.021
    [Abstract](618) [HTML](0) [PDF 325.86 K](912)
    Abstract:
    基于对松质骨结构特征的观察,应用建立在连续介质力学框架内的混合物理论基础上的两相多孔介质模型来描述人体胫骨端松质骨在撞击载荷作用下,固体骨质的应力场、变形场与孔间骨髓压力分布随时间变化的规律,研究流固之间的耦合关系。考虑固体骨质为各向同性线弹性介质,流体为理想流体,结合相应的初、边值条件,建立了描述松质骨撞击动力问题的一组完整的控制方程。然后,采用Galerkin加权残值法,通过在连续方程中引入压力ρ与罚参数β之比项,消去控制方程中的压力项,导出了松质骨在撞击载荷作用下的动力响应的罚有限元公式。用编制的有限元程序计算了松质骨平面问题的撞击动力响应。结果表明:由于松质骨中液体组分的扩散和流动,引起固体骨质和液态骨髓间的相互作用,使得松质骨呈现着一种强烈的表观粘弹性行为以及能量耗散性质.
    22  Three-Dimensional Solutions of Thick Transverse Isotropic Laminates with Clamped Edges on Elastic Foundations
    GAO Rong yu
    2000, 23(5):87-92. DOI: 10.11835/j.issn.1000-582X.2000.05.022
    [Abstract](606) [HTML](0) [PDF 303.77 K](2147)
    Abstract:
    抛弃任何有关位移或应力模式的人为假定,引入δ-函数,导出具有固支边横观各向同性叠层地基板在任意荷载作用下的状态方程。给出薄的、中厚的强厚的叠层地基板的精确解。其解满足弹性力学的所有方程,并计及每一叠层的5个弹性常数。可求出层间和板内任意处的位移和应力分量以及地基反力。
    23  Probing into Healthy Lighting
    CHEN Zhong lin YANG Chun yu
    2000, 23(5):93-95103. DOI: 10.11835/j.issn.1000-582X.2000.05.023
    [Abstract](804) [HTML](0) [PDF 319.97 K](156)
    Abstract:
    Lighting serves human's development and requirements.Healthy lighting not only meets urgent needs that the society develops ahead and healthily,but emphasizes human's effects on physiology and psychology by lighting,thus making lighting healthy.Besides,like green lighting,healthy lighting also stresses energy saving and environmental protection,and emphasizes that lighting should satisfy human's amfort able demands on physiology and psychology.So,healthy lighting is the necessity of the development of green lighting and comfortable lighting,but it more stresses the health function.In a word,healthy lighting is a lighing favourable to healthy development of human,environmnet and society,and it is a 21st century lighting according with the sustainable development strategy.
    24  Detection of Thoron in Air
    YU Yi qiao BAI Ben xuan CHEN Jia shen
    2000, 23(5):96-99. DOI: 10.11835/j.issn.1000-582X.2000.05.024
    [Abstract](728) [HTML](0) [PDF 254.41 K](157)
    Abstract:
    The activated charcoal moniter for thoron 220 Rn in air is applied into on the spot detection through analyse the method and the calculation of the data of detecting thoron 220 Rn in air.At the same time,the relevant method of settlement and the measure of improvement are introduced in accordance with disturbance which appeared when spectrum is surveyed,which in dicates that it is effective to use activated charcoal to collect and measure thoron 220 Rn in air.
    25  Submicron Particles Sizing Methods and Measurement Techniques
    GUO Yong cai GAO Chao HU Xue dong XIE Li li
    2000, 23(5):100-103. DOI: 10.11835/j.issn.1000-582X.2000.05.025
    [Abstract](738) [HTML](0) [PDF 302.66 K](130)
    Abstract:
    Due to a series of wonderful characteristics, submicron particles are of high value in national economy, defense modernization and high technology fields, with wide application prospects. Submicron particle sizing methods and techniques are difficult problems in particle research field. Modern methods for particle sizing are stated and analyzed. Some problems are discussed when these methods are used for submicron particles.
    26  Extracting the Strokes and Roots of Free Handwritten Chinese Character
    HUANG Xiang nian CHENG Ping YANG Bo PAN Bao chang PENG Jian
    2000, 23(5):104-107. DOI: 10.11835/j.issn.1000-582X.2000.05.026
    [Abstract](882) [HTML](0) [PDF 305.60 K](156)
    Abstract:
    The problems of stroke extraction and character root recognition were studied, and the strategies and the algorithms related to the problems were proposed or developed. Based on observing and studying on the writing styles and the composition features of free handwritten Chinese characters, the strategies and the algorithms, which have been showed by experimental results, have the advantages of high degree of steadiness and tolerance to character variance.
    27  Analysis on Three -Dimensional Numerical Controlled Last Machining Algorithm
    WANG Xi SHI Dao yu LUO Da li QIAN Jia yu ZHONG Xian xin
    2000, 23(5):108-111. DOI: 10.11835/j.issn.1000-582X.2000.05.027
    [Abstract](595) [HTML](0) [PDF 290.88 K](120)
    Abstract:
    On the basis of applying three dimensional discrete formative technology to describing last surface, working principle of numerical controlled last carving machine is briefly introduced. Then the algorithm of ascertaining milling cutter machining position during the machining process is analyzed in detail. We establish a three dimensional reference frame with spatial analytic geometry and obtain the spatial equation of milling cutter rotary surface. According to last machining character, we put forward a machining algorithm named Minimal Distance Method and is used to calculate the milling cutter machining position. Finally, the glabrous degree of last made by us has reached the conventional demand.
    28  R-factor Pseudo-circular Extension Method
    GONG Qu GONG Jian CAO Chang xiu
    2000, 23(5):112-115. DOI: 10.11835/j.issn.1000-582X.2000.05.028
    [Abstract](763) [HTML](0) [PDF 235.14 K](65)
    Abstract:
    The extension methods of finite length signals for sub band coding associated with wavelet transformation are investigated.Considering the weakness of the existing extension methods,an extension method is presented which is named r factor pseudo circular extension method.It turns out theoretically that the input signal can be reconstructed exactly from the truncated section of the analyzed signals by our method and the method is better than other existing extension methods,as shown in many examples.A new valid way is provided for wavelet transform application in data compression.
    29  A Class of Exact Solution to Two-Dimensional KdV-Burgers Equation
    TAN Jun yu YU Gang lei
    2000, 23(5):124-126. DOI: 10.11835/j.issn.1000-582X.2000.05.030
    [Abstract](947) [HTML](0) [PDF 141.83 K](118)
    Abstract:
    借助于类比-待定系数法,得到了二维KdV-Burgers方程的精确解,它包含了已知的结果。特别地,可以得到二维KdV方程和二维Burgers方程的解。一般地,本文的解可以表示为u=uB σuk-σu^-,其中uB是二维Burgers方程(20)的解,uk是二维KdV方程(21)的解。
    30  Coupled Fixed Point Theorems for Set-valued Nonexpansive Mappings
    YAN Jin xian
    2000, 23(5):127-130. DOI: 10.11835/j.issn.1000-582X.2000.05.031
    [Abstract](584) [HTML](0) [PDF 202.17 K](111)
    Abstract:
    In strictly convex Banach spaces, by Set valued mappings being monodromied via the optimal approximation for weakly compact convex set and using contraction mapping sequence to approximate nonexpanding mapping.The author has obtained theorems of coupled fixed point for set valued nonexpansive mappings.
    31  The EELVFM for Judging the Energy Conservation of CHP
    RAN Jing yu ZHANG Li YANG Lin
    2000, 23(5):131-134. DOI: 10.11835/j.issn.1000-582X.2000.05.032
    [Abstract](437) [HTML](0) [PDF 259.92 K](148)
    Abstract:
    Based on the Exergy Energy Level(EEL) in the process of work energy conversion about the Cogeneration Combined heat&cool and Power(CHP)and the Heating/Generating/ Cooling /Parted/Generation(HGCPG),and combined reasonably with the time infected factor of its founds(initial and operation expenses), a new method Exergy Energy Level Value Factor Method (EELVFM) ,which is more scientific for judging the energy conservation of the system , is put forward. The example is given. And the results show that the EELVFM, which can be used to judge the economical in CHP before operation, is a comprehensive thermodynamics and economics index.
    32  Thermodynamic Criterion of Enhanced Heat Transfer on Finned Surface
    WU Shuang-ying SU Fen-xian LI You-rong LIU Jiang-mei
    2000, 23(5):135-138. DOI: 10.11835/j.issn.1000-582X.2000.05.033
    [Abstract](711) [HTML](0) [PDF 253.57 K](1212)
    Abstract:
    以热力学第二定律为基础,提出了肋片强化传热的热力学判据-加肋片后与加肋片前单位传热量的熵产之比eⅡ,并以矩形直肋片为例,在工程上常见的第三类边界条件及恒热流和恒壁温两种工况下,对以上热力学判据进行了分析和讨论,并把结果与传统的肋化判据结果进行了比较。研究结果表明,对肋片的强化传热,存在一临界雷诺数,且临界雷诺数随肋片的结构参数和热流密度的不同而有所差异,同时,肋片的强化传热效果还取决于肋片和流体的导热性能。
    33  Successive Approximation by Cascade Auto Disturbance Rejection Controller
    ZHANG Rong
    2000, 23(5):139-141154. DOI: 10.11835/j.issn.1000-582X.2000.05.034
    [Abstract](590) [HTML](0) [PDF 214.46 K](864)
    Abstract:
    An algorithm of parameter identification by model compensation auto disturbance rejection controller is given. It is very efficient to the parameter identification problems of low order systems. At the same time it is not easy to get satisfying parameters of the extended state observer when the order of the controlled system is high. To solve the above problem, we combine in this paper the auto disturbance rejection controller constructed by cascade extended state observer(CESO) with the algorithm of successive approximation. Simulations show it can identify the parameter of systems with known structure effectively. In the meantime, the parameters of CESO are much easier to adjust than those of the former ESO when it is applied to high order systems.
    34  Estimation of Output Elasticity of Labor of Production Function
    ZHOU Zhuo hua ZHANG Zhong yi
    2000, 23(5):142-145. DOI: 10.11835/j.issn.1000-582X.2000.05.035
    [Abstract](631) [HTML](0) [PDF 216.75 K](893)
    Abstract:
    For the desire of Chinese computable general equilibrium model, we estimate the output elasticity of labor by using the econometric method and the method that the output elasticity of labor equal to the share of labor income in value added by the sector, and compare our results with the output elasticity of labor of other developing countries. The conclusion is that the output elasticity of labor is between the upper limit and the lower limit of the output elasticity of labor of other developing countries. So ,our results have higher reliability.
    35  Expression and Regulation of the Plant Gene Under Enviromend Stress
    ZHAO Hu cheng WANG Bo chu LIU Yan CAI Shao xi
    2000, 23(5):146-148. DOI: 10.11835/j.issn.1000-582X.2000.05.036
    [Abstract](1013) [HTML](0) [PDF 176.58 K](1709)
    Abstract:
    To investigate the adaptation mechanisms of plant gene under adversity stress.By looking up the recent literatures dealt with the plant's adaptation and response to adversity stress and reviewing previous works on the plant's adaptation mechanisms under adversity stress.Unavoidably,plant is influenced by all kinds of adversity stresses because of its immobility.But it can adapt and resist effectively to adversity stress by itself.Many researches show that under adversity stress contents of ABA and SA in the plant cells are changed apparently wiich induced many new genes expression and protein synthesis to adapt environment's change.There may be two kinds of mechanisms of the plant's adaptation to adversity stresses. 1. ABA and SA induce the synthesis of mRNA or stabilization of mRNA. 2. ABA and SA can cause the responsive proteins' accumulation and regulation after translation.
    36  Numerical Simulation of Flat Flow Combustion Process
    WEN Liang-ying LIU Cheng-quan XU Chu-shao
    2000, 23(5):149-151. DOI: 10.11835/j.issn.1000-582X.2000.05.037
    [Abstract](551) [HTML](0) [PDF 179.59 K](847)
    Abstract:
    简述了ESCIMO湍流燃烧理论的要点。采用差分数值求解的方法,对描述平展流燃烧过程的时均方程及ESCIMO湍流燃烧理论的“经历”和“统计”方程进行组合求解,得出了平展流燃烧过程近壁(z′/D=0.24)截面上的温度和组分分布,揭示了平展流燃烧区域温度最高且变化平缓,然后逐渐降低的重要特点。其温度及组分的变化规律与实验分析结果是一致的,基本能反映实际燃烧过程的特征,表明文中所阐述的数值分析方法是可行的。
    37  Maxwell Elf-DNA-LASER
    PAN Li
    2000, 23(5):152-154. DOI: 10.11835/j.issn.1000-582X.2000.05.038
    [Abstract](605) [HTML](0) [PDF 188.77 K](896)
    Abstract:
    通过介绍有趣的设想-“麦克斯韦妖”,引出物理学与其他科学包括生物、信息等科学的联系。认为物理教学除了讲述基本理论外,还应引导学生关注学科间的联系,前沿科学的进展,并有兴趣、有能力学会新东西。

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