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    20 January 2003, Volume 31 Issue 1
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    Effect of Fibers on the Morphology of Polyetherimide Modified Epoxy-amine Matrices in Unidirectional Composites
    L.Bonnaud Zhao Jian-qing Jia De-min J.P.Pascault H.Sautereau
    2003, 31(1):  1-7. 
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    Usually studies concerning the improvement of fracture resistance of epoxy based matrix composites only focus on the improvement of the interface epoxy matrix and fiber．In parallel to that‚ a usual way to improve the fracture toughness of epoxy resins consists in the addition of an initially miscible thermoplastic （such as polyetherimide） which at a particular conversion depending on composition and reaction temperature‚phase separates．The final morphology results from a competition between
    the rates of phase separation and of epoxy reaction．In this work‚the effect of reinforcing fibers （glass and carbon） on the formation of the morphology of different epoxy systems toughened by an initially miscible polyetherimide is studied．The presence of fibers in these systems is found not to affect the phase separation process of the matrix‚but the final morphology of the system is changed．The modification of the morphology is found to be less related to the nature of the fiber．The viscosity of the dif-ferent components of the matrix is found to be the determinant factor in the formation of the morphology in the composites．

    A Fast Algorithm for Computing the Intersections of a Plane with a Spatial Curve of a Certain Type
    Hong Yi Ding Shi-hong LüXiao-min
    2003, 31(1):  8-10. 
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    Aiming at a certian type of curve‚selecting the proper starting points by making full use of monotonicity of beeline‚and using the Newton tangential method‚this dissertation put forward a fast algorithm for computing the intersection of a plane with a curve of a certain type（pseudo-convex spiral）‚where the positions of the plane and the spiral are arbitrary．
    Decomposable Systems of Linear Partial Differential Equation of Second Order with Three Unknown Functions
    Diao Yuan-sheng
    2003, 31(1):  11-13,17. 
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     In this paper the systems of linear partial differential equations of second order with three unknown functions are deduced．The sufficient and necessary conditions of decomposition of the systems are achieved．This condition is connected only with coefficients and characteristic values．
    Analysis and Assessment of Productive Efficiency in Construction Industry of Guangdong Province
    Lin Chen　Wang You-song　Zhang Yan
    2003, 31(1):  14-17. 
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    A non-parametric model‚data envelopment analysis （DEA）‚is employed in this paper to assess the productive efficiency in construction industry of Guangdong Province during the period of 1985—2000．The results show that the productive efficiency generally increased at an average annual rate of3．76％．This research gives an understanding of input -output relation and productive efficiency in Guangdong’s construction industry within the period．
    Synthesis of Unsymmetrical Conjugated Phenylacetylene Dendrimers with an Anthracene Core
    Peng Xiao-hong Y uan Tie　 Peng Xiao-chun
    2003, 31(1):  18-21,25. 
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     The phenylacetylene dendrimers（PADs）‚which consist of a phenylacetylene backbone and an anthracene core‚were synthesized up to the third generation by the convergent method via only one synthon and two sets of reaction conditions．The composition and structure of new dendrimer was identified by elementary analysis and NMR spectra （1 H NMR and 13 C NMR）．
    High Secreted Expression of Human Bone Sialoprotein in Pichia Pastoris
    Dong Yan Wang Jie Yang Lian-sheng Zhang Hong-bin Zheng Wen-ling
    2003, 31(1):  26-29. 
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    Rea- l time Inspection on Quality During Powder Metallurgy Compacting Process
    Lu D- i fen　 Chen Sen-feng　 Wu Jian-qi
    2003, 31(1):  30-37. 
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     Inspection and control of the quality at rea- l time during P／M compacting process are necessary techniques for the automatization of powder metallurgy production．The relations between the density‚mass of green compact and time series model parameters based on the vibration signal of the mold system during P／M compaction are analyzed by experiments．The practicability and validity of utilizing time series model to identify the density and mass of green compact are investigated and verified．This paper presents a new approach to monitoring the quality of production at rea- l time during P／M compacting process．
    Rea- l time Inspection on Quality During Powder Metallurgy Compacting Process
    Chen Ge-wei
    2003, 31(1):  34-37. 
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     Inspection and control of the quality at rea- l time during P／M compacting process are necessary techniques for the automatization of powder metallurgy production．The relations between the density‚mass of green compact and time series model parameters based on the vibration signal of the mold system during P／M compaction are analyzed by experiments．The practicability and validity of utilizing time series model to identify the density and mass of green compact are investigated and verified．This paper presents a new approach to monitoring the quality of production at rea- l time during P／M compacting process．
    Design on Rectangular Planar Magnetron Sputtering Target Without Shielding Cover
    Chang Tian-hai
    2003, 31(1):  38-41. 
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    The traditional upper limit of magnetic induction density B parallel to target surface in rectangular planar magnetron sputtering target has been increased by analyzing‚designing and experimenting．The results show that shielding cover can be discarded‚naked target can be adopted and the B can exceed0．05T greatly and achieved0．09T ‚under the condition of the of magnetic induction density paral - lel to cathode bottom and sides under0．0005T by shielding‚and at the same time the cathode upper surface is covered with the same kind of target material．Further more‚the increase of B reduced greatly the touching off and keeping discharge voltages during magnetron sputtering coating‚which gives another approach to lower voltage magnetron sputtering．
    Determining Parameter of Tyre Curing Temperature Prediction Formula by Method of Time-delay Cross Correlation
    Jiang Nan Zhang Shu-kuan Zhang hai Cen Han-zhao
    2003, 31(1):  42-44. 
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     The state of vulcanization of the tyre is mainly determined by the temperature-time history．But in real production‚the inner temperature of the tyre is unable to be measured．In this paper‚the author carried out many analyses of both the experiment and FEA data to find out the relationship between inner and surface temperature during vulcanization．Through the method of time-delay cross correlation‚the parameters are determined for the regressive prediction formula‚from which the vulcanization process control will benefit．
    Study on Microchip Controlled Inverter GMAW-P Welding System
    Zeng Min, Cao Biao, Huang Shi-sheng, et al
    2003, 31(1):  45-47. 
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    An inverter GMAW-P welding system is designed in which the microchip is adopted as the central controller through studying the GMAW-P welding process．The structure and working principle of the system and the makeup of the control circuit are discussed in detail．The method of improving the control precision and the system software are also introduced．The result shows that the system has simple structure and many adjustable parameters‚which can control the GMAW-P welding process precisely．
    Ultrasonic Seam Welding of Copper Plates and Tubes for Collecting Solar Energy
    Liu Ya-jun, Tang Yong, Wan Zhen-ping, et al
    2003, 31(1):  48-50,56. 
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    The mechanism of ultrasonic seam welding of copper plates and tubes for collecting solar energy was investigated. It is concluded that welding seam is formed under the jointly action of three factors： atoms permeating on the welding interface, melt welding between contacting apexes and interlock in the welding seam interface. In addition, effects of welding specimen hardness and parameters on tensile strength of welding were studied by experiments．
    Forecast of Engine Emissions Characteristic Based on Generalized Regression Neural Network
    Yu Ming, Lin Dong-yan, Sun Guo-bin, et al
    2003, 31(1):  51-56. 
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    The Neural Network is one of the most important artifical intelligence technology at present． It simulates the structure of human brain and its function of dealing with or memorizing the information． The Neural Network is adept at learning from the input and output data and draw out an useful information．The predicting of the performance of engine is to predict the engine performance using the structure and operation parameters of the engine．So we can use the learning peculiarity of Neural Network to show how the structure and operation parameters of the engine affect the performance of engine‚and describe them with a Network model．The authors of this article discusse how to choose the suitable network and uses it to construct the model of engine instead of physical model‚then give an example of an engine model of emissions‚and programs on MATLAB.
    Improvement of Characteristics in Linear Region of n-MOSFET Using Backsurface Ar ＋ Bombardment#br#
    Cai Rui-bin Li Yun-hong Chen Zi-jian
    2003, 31(1):  57-59,69. 
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    This paper describes the method and principle of purification of CO and HC in exhaust emissions from enging．Through experiment‚whether the purification effect of CO and HC in exhaust emission is improved through heating automobile emission is discussed.
    Synchronous Rectifier Analysis of Forward Converter under the Condition of Light Load
    Xie Yun-xiang Wang Hao
    2003, 31(1):  60-64. 
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    While the converter works at light load‚the output filter inductor current will go negative through MOSFET in synchronous rectifier and the circulating current will be formed．In order to solve this problem‚the detection method of light load condition of converter used by UC3842is proposed in this paper‚meanwhile‚the technique has also been studied which is used to make the inductor current cannot be flow negatively by switching off the MOSFET while converter works at light load．The theory analysis and experiment have proved that the proposed method is effect‚the converter efficiency has also been improved a lot at light load． 
    Improvement of Characteristics in Linear Region of n-MOSFET Using Backsurface Ar ＋ Bombardment
    Huang Mei-qian, Chen Ping, Li Xu, et al
    2003, 31(1):  65-69. 
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    Improvement of the characteristics in the linear region of n-MOSFET using the backsurface Ar ＋ bombardment has been investigated．A low energy （550eV） argon-ion-beam is applied to bombard the backside of n-MOSFET chip‚thus the electrical characteristics of the transconductance‚channel conductance‚threshold voltage‚effective inversion layer carrier mobility and low-frequency noise of the devices in the linear region can be improved．The experiment results indicate that‚as the bombardment time increases‚the transconductance‚channel conductance and effective inversion layer carrier mobility increase at first‚and then decrease；the change tend of the threshold voltage is on the contrary；but the low-frequency noise decreases evidently after bombardment．It is proved that the improvement of these parameters is due to the decrease of interface state density and fixed charge density． 
    Analysis of Discrete Recombination Operators in Real Coded Genetic Algorithms 
    Zhou Yong-hua Zhao Ping Mao Zong-yuan
    2003, 31(1):  70-73. 
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    The combination capabilities of three types of discrete recombination operators‚one point crossover‚multiple point crossover and uniform crossover operators in real coded genetic algorithms are analyzed with combinatorics．The combination capability of the operators is measured by the number of different chromosomes produced by the operators．It is shown that operating on the same pair of parent chromosomes‚one point crossover can produced at most 2（ n－1） different chromosomes‚multiple point crossover2C k n－1‚and uniform crossover2（2n－1－1）．Function optimization experiments show that which operator works better in an algorithm depends on both the combination capability of the operator and the problem to be optimized．
    Application of ART2 Classifier Based on Modified Algorithm to Glass-ceramic Color Garding#br#
    Ai Jiao-yan Zhu Xue-feng
    2003, 31(1):  74-78. 
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    On-line Quality Monitoring and Management Platform for Automatic Arc Welding Process#br#
    2003, 31(1):  79-83. 
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     This paper deals with the establishment of quality monitoring platform for automatic arc weld-ing process．It adopts the control workstation as well as the sever to realize the quality monitoring for every quality control node and total quality management for whole production line using client／sever architecture．The paper also discusses the application of the data mart and mining technique in this system．
    Realization of PLC Based on ISP-Micro-controller
    Zhu Ning-xi Zhang Qi
    2003, 31(1):  84-87. 
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    Characteristic Comparison of Microwave Vacuum Popping of Popcorn and Maize#br#
    Huang Ru-qiang　Rui Han-ming　Zeng Qing-xiao
    2003, 31(1):  88-90,96. 
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    The characteristics of microwave vacuum popping of popcorn and maize according to index of the volume expansion ratio were studied in this paper．With SEM their mechanisms were examined．It was proved that the structure was the important factor which influenced the popping characteristic of popcorn and maize．The fact was found that the popping characteristic of popcorn was better than that
    of maize‚and that the quality of popcorn flower of popcorn and its texture were also better‚and that the volume expansion ratio of popcorn was higher than that of maize．The volume expansion ratio of popcorn was optimum when the vacuum was26．66kPa．
    Overview of Vibration-based Damage Identification Methods
    Han Da-jian 　 Wang Wen-dong
    2003, 31(1):  91-96. 
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    Vibration-based damage identification is one of the few methods that detect changes in the structure on a global basis．This paper summarizes the current state-of-the-art of the technology．A discussion of critical issues for future research in the area of vibration-based damage identification is also presented．
    Effect of Fibers on the Morphology of Polyetherimide Modified Epoxy-amine Matrices in Unidirectional Composites#br#
    L．Bonnaud Zhao Jian-qing Jia De-min J．P．Pascault 　 H．Sautereau
    2003, 31(1):  97. 
    Asbtract ( 45 )   PDF (362KB) ( 111 )  
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     Usually studies concerning the improvement of fracture resistance of epoxy based matrix composites only focus on the improvement of the interface epoxy matrix and fiber．In parallel to that‚a usual way to improve the fracture toughness of epoxy resins consists in the addition of an initially miscible thermoplastic （such as polyetherimide） which at a particular conversion depending on composition
    and reaction temperature‚phase separates．The final morphology results from a competition between the rates of phase separation and of epoxy reaction．In this work‚the effect of reinforcing fibers （glass and carbon） on the formation of the morphology of different epoxy systems toughened by an initially miscible polyetherimide is studied．The presence of fibers in these systems is found not to affect the phase separation process of the matrix‚but the final morphology of the system is changed．The modifi -
    cation of the morphology is found to be less related to the nature of the fiber．The viscosity of the different components of the matrix is found to be the determinant factor in the formation of the morphology in the composites．
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