Table of Content

20 October 2003, Volume 31 Issue 10

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Effects of Modified Montmorillonite Master Batches on the Crystallization Property of Polypropylene



Zhang Y ong-hua, X u De-xiong, Zhong We-i dong, et al

2003, 31(10):  1-5. 

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Organic montmorillonite-filled polypropylene was prepared by blending functionalized polyethylene wax-organic montmorillonite intercalated master batches with polypropylene．The effects of the organic montmorillonite master batches on the crystallization property of polypropylene were investigated by means of X-ray diffraction‚isothermal and non-isothermal differential scanning calorimetry analyses．Non-isothermal crystallization kinetics of polypropylene was also studied by the modified Avrami theory of Jeziorny．The results indicate that some organic montmorillonites can be intercalated by polypropylene‚leading to an increase in their interlayer distance‚and the crystal form of partial polypropylene is changed fromαtoβwith the existence of organic montmorillonite master batches．The filled polypropylene crystallizes fastest at 400 K．The results also show that organic montmorillonite master batches can effectively accelerate the heterogeneous nucleation of polypropylene and increase its rate of crystallization and crystallizing point‚but they do not affect the rate constant of crystallization． 

Mechanism of Fiber Forming of Screw Extrusion for High Performance Engineering Plastics



X u Zhong-bin Wu Shun-ying Y i Xiao-su

2003, 31(10):  6-10. 

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Based on the rheological characteristics of the melts of high performance engineering plastics at drawing and cooling stages‚and by choosing White-Metzner constitutive equation‚the unsteady enlongational flow mathematical model of the screw extrusion spinning process of high performance engineering plastics fiber was developed．The mathematical model was simplified and the numerical computation with difference method was conducted．Thus the velocity and elongational rate of PEEK filament on the spinline were obtained‚which provides theoretical reference for the spinning equipment design and parameter determination of the spinning process of screw extrusion for high performance engineering plastics． 

Arc Plasma and its Power Supply with High Efficiency



Huang Sh-i sheng, Du Gu-i ping, Li Y ang, et al

2003, 31(10):  11-14,19. 

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The classification and applied circumstance of plasma were introduced and the basic laws of energy transfer for acr plasam were discussed．According to the demand of arc plasma for power supply‚ a novel large inverter power supply with soft-switching was presented and its characteristics and efficiency were studied．The results show that the inverter power supply has excellent characteristics and high efficiency‚and meets the demand of arc plasma process well．

Fuzzy Controller of Pulsed MIG Welding Power Source 



Wu Ka-i yuan, Li Y ang, Huang Sh-i sheng, et al

2003, 31(10):  15-19. 

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A fuzzy controller‚which is realized by Look-up Table （LUT） method based on MATLAB Fuzzy Logic Toolbox‚was developed to overcome the disadvantages of weak arc voltage self-adjusting ability in pulsed MIG welding with small diameter aluminum wire．In this controller‚the peak arc voltage‚Uf‚is controlled by the pulse base time‚Tb‚by means of the feedback of arc voltage．The membership functions‚fuzzy linguistic control rules and fuzzy linguistic control table of fuzzy controller were also discussed．The results of the experiment demonstrate that the newly developed fuzzy controller has strong arc voltage adjusting ability to obtain the stabilities of arc voltage and welding process．

Prediction of the Cutting Force of Chamfered Cutting Edge During the Cutting Process Using Finite Element Method



Deng Wen-jun, Xia Wei, Zhang We-i wen, et al

2003, 31(10):  20-23. 

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A finite element model was presented to predict the cutting force of chamfered cutting edge during the cutting process．The flow stress of the workpiece was taken as a function of strain‚strain-rate and temperature in order to take into account the effect of large strain‚strain-rate and elevated-temperature on material properties．The cutting process was simulated from the initial to the steady-state of cutting force．Chip separation was achieved by the function of the adaptive remeshing founded in commercial finite element code Marc．The proposed finite element model was verified experimentally for a range of cutting conditions and gave significantly better prediction of cutting forces．The effect of geometry parameters of the chamfered cutting edge on the cutting forces was also discussed．

Super-resolution Image Restoration Based on Improved POCS Algorithm



Li Hu-i fang Du Ming-hui

2003, 31(10):  24-27. 

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An improved POCS （Project onto Convex Sets） was proposed to solve the edge oscillatory effect caused by general POCS．By this algorithm‚the edge pixels of image were managed with special technique‚while the other pixels were modified‚thus the edge oscillatory of the restored image was eliminated．Contrastive experiment between the improved and general POCS algorithms was conducted which verifies the validity of the improved POCS algorithm．

Frame of Open Numerical Control System Based on RT-Linux



Li We-i guang, Zhao Bo Zhou, Jian-hui, et al

2003, 31(10):  28-31. 

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Based on the research on the national standard of Open Numerical Control System‚a frame of the system based on RT-Linux was given．The software of the system is made up of open CNC kernel and numerical modules．Then the CNC function modules were systemically plotted and studied‚and the working flow of CNC components and the example of interpolate-component interface were given． Users can reform function modules or develop the needed function modules based on this frame‚to build an open numerical control system that possesses control performance of high-speed and high-precision．

Product Model Based on Extended Object-oriented Petri Net



Fan Chong-gui Wen Jun Wen Gu-i hua Ding Y ue-hua

2003, 31(10):  32-35. 

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A product model was proposed to support creative design process with the ability of depicting the sta-tic structure of product and the dynamic working process．The model is integrated with objectoriented paradigm to implement encapsulation‚abstract and hierarchical modeling of the product‚particularly where the attribute value can be extended to manifold．And then the model employs Petri net to describe the dynamic working process of the product．The proposed model can be used to effectively support the creative design of product． 

System Dynamics Model of Regional Logistics and its Algorithm Analysis 



Gui Shou-ping Zhu Qiang Lu L-i fang LüY ing-jun Gui Cheng-fei

2003, 31(10):  36-40. 

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According to the development trend of Chinese regional economy‚and with the organic combination between the basic principle of system dynamics and modern logistics‚a new idea and the corresponding modeling method of system dynamics of regional logistics were investigated．Then‚according to the characteristics of the system dynamics model‚the mathematical equation of the system was deduced．By the analysis of logistics system of the Pearl Delta area‚the practicability of the model and the instructional meaning of the theory were proved‚which provides a new research direction for the integration and harmony of regional logistics system．

Automobile Crash-avoiding Fuzzy Controlling System Based on Photo Recognition and its Simulation



Luo Y u-tao

2003, 31(10):  41-45. 

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One kind of automobile crash-avoiding fuzzy controlling system was designed based on photo recognition‚and the mathematical model for safety distance calculating was constructed．The system consists of photo recognition system‚velocity sensor‚judgment system and fuzzy control module．With the Simulink software of MATLAB‚a simulation model of the system was proposed．The feasibility of the system and the correctness of the model were validated by the simulation and analysis of four working conditions．

Design of the Main Frame of Telecom Local Network Computer IBSS



Zheng Wei Y u Shou-yi

2003, 31(10):  46-50. 

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Aiming at the structural weakness and the function lack of the old telecom “97” business support system‚and based on the multiplayer distributing computer mode‚the system structure of the client／middle layer server／database server （C／S／S） was constructed to build the new Telecom Integrated Business Support System （IBSS）‚and the idea of operating the logical data layer in atom service was proposed．The structure of business system‚the abstract of the core entity relations and the technology applied to the system were given．

Characteristics of Current Transportation from n-Si into Lamp Heating Rapid Thermal Nitridation Ultra-thin SiO2Films

Feng Wen-xiu Zhang Heng Chen Pu-sheng Tian Pu-yan

2003, 31(10):  51-54. 

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By the rapid thermal nitridation （RTN） of ultra-thin （10 nm） SiO2 films‚the ultra-thin SiOxNy dielectric films had been prepared with tungsten-halogen lamp as radiation source‚and the Al／nSi／SiOxNy／Al capacitors had been fabricated too．The characteristics and their variation with nitridation time of current transportation from n-Si to lamp heating rapid thermal nitridation ultra-thin SiO2films of the capacitor samples were investigated．The results show that in the lower field region the leakage current is little．When the field is in the tunneling region‚the current changes following the F-N rule． When the field is more stubborn‚two phenomena may occur： one is that the characteristics follow F-N rule until the breakdown‚and the other is that the characteristics move down and depart F-N rule until the breakdown．As the RTN time increases‚I-E curves move up all．All these experimental results have been discussed． 

A Novel Method for Determining the Peak Position from Noisy Overlapped Signals ∗

Zhang Y ong-qing Wang L-i shi Mo Jin-yuan

2003, 31(10):  55-57. 

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A new method called continuous spline wavelet transform（CSWT）for determining the peak position of noisy overlapped signals in analytical chemistry was proposed by selecting the second order B－spline wavelet as analyzing wavelet．Under suitable dilation‚the processed signal is similar to the signal obtained by the4th order differential．The results show that the resolution and the signal－to－ noise ratio of signal processed by CSWT are enhanced comparing with those of overlapped signal．By CSWT‚one can obtain the number of overlapped peaks and the corresponding peak positions from noisy overlapped signals． 

On-line Monitoring and Dynamic Simulation for Hydraulic Generator Vibration 



Gui Zhong-hua Han Feng-qin

2003, 31(10):  58-60,69. 

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An on-line vibration monitoring system for the hydraulic generator was developed．The system is subdivided into three subsystems‚namely‚data collection‚vibration analysis and communication．To counter the difficulty of acquiring rea-l time fault signals in field debugging‚a dynamic simulation system had been developed．It can simulate the process of rea-l time data collection‚and sends the collected data to the vibration analysis system‚where time-domain analysis‚frequency-domain analysis‚etc．‚are implemented to locate the vibration source of the unit．

Scaling Analysis for Inducing Prandtl Boundary Layer Equation



Fan Fu-mei Liang Ping Long Xin-feng

2003, 31(10):  61-64. 

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By selecting intrinsic reference scaling‚and according to some related properties of continuous function‚the magnitude of each tiny quotient in Navier-Stokes equation was determined based on some experimental materials．Then scaling analysis was carried out to make each part of the equation non-dimensional‚and the magnitude of each tiny quotient of the equation was evaluated．By removing the parts whose magnitude was less than1‚Prandtl boundary layer differential equation was induced successfully．To a certain extent‚this method discloses the mathematical and physical essence of boundary differential equation． 

A New Multifunctional Diesel Additive



Hu Zhi-hua Jiang Y an-bin Dan Dong-ming Qian yu Zhang Li-juan

2003, 31(10):  65-69. 

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A new multifunctional diesel additive was developed by mixing surfactants‚oily solvent and water ‚etc ．together ．The results of diesel engine idle test and platform test show that the additive improved combustion and effectively reduced deleterious emission of CO‚ NOx ‚ HC and smoke grade ．The major factors affecting the performance of the additive were discussed ．The micro-explosion mechanism was adopted to explain the action mechanism of the additive ．

Preparation of Lithium Nickel Cobalt Oxide for Lithium Ion Battery Cathode Material 



Li Jun Zhu Dong-sheng Wu Hu-i jun Tian J-i ping Guo Shao-bin

2003, 31(10):  70-72,80. 

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 lithium ion battery；cathode material；lithium nickel cobalt oxide；preparation 

Preparation of Colloidal Crystals and Three-dimensional Porous Materials



Tang Tian Zeng Fang Li Na Sun Za-i wu Tong Zhen

2003, 31(10):  73-76. 

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The monodispersed and highly charged poly（styrene／sodium styrene sulphonate） spheres were prepared with their particle sizes ranging from80to320nm by emulsifier-free emulsion polymerization． A new and simple procedure for producing highly ordered colloidal crystalline template was developed‚ and the solvent-free colloidal crystals were formed on the surface by electrostatic interaction‚surface tension as well as the ion diffusion during the evaporation．Then the so-l gel solution was infiltrated into the interstitial space of the colloidal crystals through capillary effect and ordered inverse opals were obtained after the solidification of the so-l gel solution and the calcification of the polystyrene beads．

Mathematical Model of Curcumin Adsorption Purification



Wang Fu-rong Guan Jian-yu Lu Y ing-sheng

2003, 31(10):  77-80. 

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The adsorption isotherm and effluent curves of curcumin solution on a column packed with D4020adsorbent were studied and simulated by a mathematical model．It is shown that the adsorption isotherm curves can be fitted by Freundlich equation．The coefficient kf of the equation is0．3152and the exponent nf is0．7443at25℃ by linear regression．The mathematical model was solved numerically by ordinary differential method to describe the effluent curves‚and the theoretical results fit the experimental results well．

Flooding and Floating in Waterborne Coatings

Huang Y ing Cheng Jiang Wen Xiu-fang Y ang Zhuo-ru

2003, 31(10):  81-85. 

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Flooding and floating affecting the appearances and the effect of latex paint and film were investigated．The results show that too wide distribution of the particle sizes of pigment and filling arouses flooding and floating．Different dosages of pigment （TiO2） or filling （kaolin） bring about diverse degrees of flooding and floating．Coatings that show no phenomena of flooding or floating will possibly do when diluted．Using dispersants or thickeners with hydrophobic constituents can increase viscosity‚reduce surface tension‚and are all good for preventing or lightening floating and flooding． Contrast test reveals little influence of processing technique on floating or flooding．

Design of the Weather Court Cable-truss Hybrid Structure of Zhongshan University



Zhang Heng-chun Y an Xi Wang Hong Zhao Shan

2003, 31(10):  86-89,96. 

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The design of the weather court of Zhongshan University was carried on by using cable-truss bybrid structure．The structural characteristics and the static and dynamic characteristics of the system were researched．The determining metod of cable’s pre-stress and the construction of nodes were investigated too．