Journal of South China University of Technology(Natural Science Edition)

Degradation of Vinyl Chloride in Water by the Chemical Oxidation of O3／H2O2 and Its Kinetics

Zhong Li Qi Ming Zhan Huai- yu

2004, 32(12): 1-4.

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The chemical oxidation degradation（O₃／H₂O₂）of vinyl chloride in water and its kinetics were investigated
at298K and with the pH value of3～11by utilizing the Stopped-flow Spectrometer reactor．A kinetic model for the
degradation of organic pollutants was then established by means of theoretical analysisand the reaction kinetic data
were obtained by the regression analysis of experimental data．It is found that the experimental results are in good a-
greement with the theoretical model．

Preparation of Carbon Black-Filled NBR-based Composites by Reactive Modification in Latex

Li We-i qing Luo Yuan-fang Jia De-min

2004, 32(12): 5-10.

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Methyl methacrylate （MMA） or butyl acrylate （BA） as the monomers was added into the nitrile-butadiene rubber （NBR） latex containing carbon black （HAF） and were grafted onto the NBR macromolecular chains in the latexthus forming chemical bonds on the surfaces of HAF．As a resultthe disparity of carbon black in the rubber matrix was improved；the combination between the rubber and carbon black was strengthened；and the carbon black-filled NBR-based composites with excellent mechanical properties and strong heat-resistance were obtained．The grafting effects of NBR and HAF onto the monomers were studied．The mechanical propertiesthe thermal properties and the dynamic mechanical properties of the composites were also investigated．The microstructures of the composites were finally explored by means of SEM．

BP Neural Network-based Software Measurement for DM423 Biomass During Flask Cultivation

Li Bing, Guo S-i yuan, Li Lin, et al

2004, 32(12): 11-15.

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The relationship between the initial conditions （initial glucose content and initial biomass） and the biomass during the flask cultivation of Baeillus cereus DM423was described by BP neural network．A2-6-3topo-logy of the BP neural network was then constructed．The estimation results of biomass by the BP neural network show that there is little difference between the calculated values and the experimental oneswhich means that the constructed neural network has a good generalization．The proposed network also promises rather good prediction results when the initial glucose contents are4．25and27．30g／Land the average relative error of the estimation is1．95％．

Cultivation of the Hairy Roots of Trichosanthes Bracteata Voigt in the Photobioreactor

Xu Ming- fang, Huang Wei- jian, Ge Xiang- feng, et al

2004, 32(12): 16-19,24.

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Agrobacterium rhizogenes R1601was used to induce the hairy roots from cotyledons and stems of Trichosanthes bracteata VoigtThe cultivation system for the growth of hairy roots was established in a photobioreactor． The effects of light intensitydissolved-oxygen saturation and carbon source on the growth of hairy roots were then investigated．The results show that the specific growth rate of hairy roots maintains higher level when the dissolved-oxygen saturation and light intensity are respectively controlled at 80％ and 25 W／m 2．It is also shown that sucrose sources affect remarkably growth of hairy roots than glucose．When the sucrose concentration is controlled at30～40 g／Lthe biomass in the two grades culture system（9．5g／L） is20％ more than biomass of hairy roots in the single culture system（7．2g／L）．

Denitrification of Low-strength Domestic Sewage by Using the SAFB-BAF Combined System

Ling Xiao Hu Yong-you

2004, 32(12): 20-24.

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The denitrification performance of the special anaerobic film bed （SAFB） and biological aerated filter （BAF） combined system in pilot scale （with a daily treatment quantity of500m 3／d） for low-strength domestic sewage was assessed under the conditions of different aeration amounts and influent water quality．It is found that the average removal rates of TN and NH4 ＋-N are respectively27．84％ and83．39％ when the ratio of air to water is greater than 2∶1while being respectively29．15％ and70．88％ when the ratio is less than2∶1．So the ratio should be controlled from2∶1to3∶1．It is also found that the carbon source has no effect on the denitrification when BOD5／TN of SAFB intake is more than4but it seriously influences the nitrification when CODcr／TN of BAF intake is more than5．

Oxidation of Diesel Particulate Matters by Using Copper-contained Catalysts

Deng Yao-jie, Fu Ming-li, Ye Da-i qi, et al

2004, 32(12): 25-29. doi:1000-565X(2004)12-0025-05

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Catalysts Cu-K-V-［-Me（Me＝PtMnO₂NiOor SnO₂）］／TiO₂／γ-Al₂O₃／cordierite were prepared and then mixed with the particulate matters （PMs） from a min-i type diesel engine．Thusthe activities of the catalysts were tested by DSC and TG analyses．It is indicated by DSC analysis that the ignition temperature of soluble organic fraction （SOF） can be reduced to432．62K when Cu-K-V-SnO2is usedwhich is much lower than the corresponding 523．27K when no catalyst is used．Cu-K-V-NiO can help reduce the temperature to687．97K for the combustion of graphitic solid fraction （GSF）．Furthermorethe temperature for the complete combustion of PMs reaches only766．88 K with the presence of Cu-K-V-NiO．It is also indicated by TG analysis that the presence of Cu-K-V-NiO leads to an abatement efficiency of90．83％ at700．65Kaccompanied by91．6％ at710．05K for Cu-K-V-Ptand81．7％ at 725．65K for Cu-K-V-SnO₂respectively．The maximum reduction of soot reaches38％ when Cu-K-V-SnO₂is used in real exhaustwhich is little higher than the value of25％～35％ for commercial products．

Investigation into the Multiple Transverse Cracks in Cross-ply Laminates

Zeng Qing-dun Zhang Ning

2004, 32(12): 30-33,39.

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On the basis of the shear-lag theorya layered shear-lag model was established to study the multiple transverse cracks of the matrix in90°-ply for cross-ply laminates under tensile loads．The crack distance and crack density were then calculated while taking the residual thermal effect into accountwith the results fitting perfectly with the existing experimental values．Thusthe correctness and reliability of the proposed model and method are further verified． The calculated results also show that the crack density is related to the applied stress in the far fields and that the greater the applied stress isthe greater the crack density will be；and a cluster of saturation transverse cracks with equal interval distance in90°-ply emerges when the applied stress reaches or exceeds a certain value．

Effect of the Thickness of Carbon Fiber Laminate on the Failure Mode of Strengthened RC Beam

Sun Ru-i feng Huang Pe-i yan Zheng Xiao-hong

2004, 32(12): 34-39. doi:1000-565X(2004)12-0034-06

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In this paperby means of theoretical derivation and experimental verificationthe effect of the thickness of carbon fiber laminate （CFL） on the failure mode of the strengthened RC （Reinforced Concrete） beam was investigated．In the investigationa method and corresponding equations were proposed to estimate the fa-i lure modes of4 groups of beams．The theoretically estimated results show that the failure mode of the RC beam strengthened with CFL changes with the thickness of CFL and that 4kinds of failure modesnamelythe tension fracture of CFLthe debonding fracture of interface or the cover concrete separationthe concrete crush and the mixed failure modeare respectively related to the4thickness regions．All these estimated results were finally verified by some tests．

Geometric Deformation Monitoring of the Roof Truss-string Applied to Guangzhou International Conference Exhibition Center

Deng Hui, Guo Xiang-rui, Su Cheng, et al

2004, 32(12): 40-42,55.

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The large-span prestressing truss-string applied to Guangzhou International Conference Exhibition Center is a new-type structure．In this papermodern geodetic instruments and technologies were used to monitor the geometric deformation on the spotwith the aim of investigating the real deformation of the truss-string in different construction periods．Deformation parameters and characteristics of the truss-string in different construction periods were then obtained．The results indicate that the displacement of the truss-string mostly happens in Z directionand the deformation at the middle observation point is the biggest．It is also indicated thatin the tension periodthe actual deformation proves bigger than the theoretical calculation．

Experimental Research on the Unbonded Prestressed Concrete Flat Slab-T-shaped Column Connections Under Gravity Loads

Li Guang-xing Cai Jian

2004, 32(12): 43-46.

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An experimental research on six ful-l size flat slab-T-shaped column connections was carried out to investigate the punching shear behavior．The punching shear behavior and failure features of the connections were expounded and the stress variation of the unbonded prestressed bars was analyzedas well as the strain variations of the top flexural reinforcements and the stirrups in slab．Moreoverthe ultimate punching shear strengths of the specimens were compared．Experimental results show that the prestressed concrete specimens are of better punching shear behaviors and the behaviors improve with the increasing of prestressing and flat slab thickness．

Simulation Analysis of the Prestressing Effect on the Curved Box Girder Bridge

Li Xin- ping Ren Hua

2004, 32(12): 47-50.

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In order to reduce the complexity arising from the difference in camber radius of the internal and external webs in the design of curved box girder bridgesa real curved box girder bridge was analyzed by using the space entity simulation model．By comparing the analytical results with the measured onesit is found that unreasonable loading will occur in the symmetrical prestressing tendons if the straight box girder is irrational．A method to dispose the prestressing bunch was finally investigatedthus providing references to the design of curved box girder bridges．

FE Analysis and Application of the Thermal Field in the Interior Decoration Mould of Auto Ceiling

Du Qun-gui Zou Jian-huang Liu Shao-hong

2004, 32(12): 51-55.

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The interior decoration mould of auto ceiling was modeled by using the software of PRO／ENGINEER．The thermal field and temperature-time history in the heat-pressing moulding process were also simulated by using ANSYS． It is found that the position of heating panels and the temperature setting of sensors are the key factors affecting the moulding．By comparing the simulated results with the actual onesit is found that they fit very well．Thusa heating scheme was put forward to solve the problems of uneven temperature and partial singeing．It is concluded that the proposed scheme is correct and feasibleand can improve the productivity and reduce the production cost．

Local Refinement of 2D Finite Element Meshes

Huang Xiao-dong Du Qun-gui

2004, 32(12): 56-60.

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Three modes for refining finite element meshes locally are proposedin which meshes are refined near the key-pointin the circle area or in the rectangle area．In the embedded regions that are constructed for refined meshes generationan algorithm based on Delaunay triangulation is then employed for the generation of graded meshes．In this algorithmnodes and elements are generated dynamically and simultaneouslyand the refined meshes generated in the embedded regions are embedded into the original meshes．As a resultmeshes are refined in the key areas．Examples show that the meshes refined by the proposed method are of good quality and can satisfy the requirements of finite element analysis．

Motor Servo Driver Based on Intelligent Power Module

Wu Jie, Lei Chun- lin, Chen Yuan- rui, et al

2004, 32(12): 61-64,73.

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The design of the motor servo driver based on Intelligent Power Module （IPM） was introduced in this paper；its working principlehardware frame and the design of the PWM （Pulse Width Modulation） servo amplifier were clearly presented．The proposed servo driver was then applied in different operation conditions and the newly proposed controlling algorithmnamelyADRC （Auto Disturbance Rejection Controller）was verified by experiments．The results prove that the designed servo driver is of good performancehigh reliability and simple hardware frameand can meet the high-speed requirement of motor control systems．It is also concluded that ADRC has better disturbance rejection ability and robustness than the traditional PID controller．

Exponential Stability of Stochastic Differential Systems with Distributed Delays and Parameter Uncertainties

Bao Jun- dong Deng Fei- qi Luo Qi

2004, 32(12): 65-69. doi:1000-565X(2004)12-0065-05

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In this paper, a class of linear stochastic differential systems with distributed delays and parameter uncertainties is considered, with the purpose of stating the sufficient conditions for the exponential stability in mean square for a class of more generalized linear stochastic systems with distributed delays．The delay-dependent criteria for the exponential stability of the systems are then given．An example is finally presented to illustrate the correctness and applicability of the proposed method．

Exponential Stability of Stochastic Neutral Systems with Distributed Parameters

Zhao Bi- rong Deng Fei- qi Luo Qi

2004, 32(12): 70-73.

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Based on stochastic Fubini theorem, the system depicted by a stochastic partial difference equation is trans-lated into a stochastic ordinary difference equation．By constructing a mean Lyapunov function with respect to the space variables and using Itôformula under the integral operators, we directly study the exponential stability in mean square of stochastic neutral systems with distributed parameters．Some sufficient conditions of stability in mean square of a class of stochastic neutral systems are obtained．

Load Balancing of the Distributed System Based on Multi-agent

Yan Jun-hua Zhang Huan-chun Jing Ya-zhi

2004, 32(12): 74-79.

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In order to realize the dynamic load balancing of the distributed systema new dynamic load balancing algorithm was proposed based on Mult-i agent．In this algorithmthe receiver-initiated strategy is adopted and the tasks are dynamically migrated by the mobile Agent in the running process of the systemaccording to the current status of load on each host．The load status of hosts was also investigatedwith a status index of 〈 LCLM〉 being proposed． This index shows the differential characteristics of each computer in the distributed measurement and control system． The functionstructure and communication of Agent were then introduced in detail and an application was presented to demonstrate the communication of Agent and the creation of the mobile Agent．The algorithm was finally realized in the distributed measurement and the control system．The experimental results show that the algorithm can decrease the network transmissionsave timeimprove the system efficiency and attain dynamic load balancing．

Multi-objective Optimization of System Reliability

Li Ying- chun Hao Zhi- feng Wang Ning- ning

2004, 32(12): 80-82,93.

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The problem of multi-objective optimization has many sets of optimal solutions.The traditional method to
solve the problem is to translate the multi-objective into several single objectives and then resolve the invert problemby
the single-objective optimization technique .Unfortunately, this method has many inherited flaws.As a parallel algo-
rithm , genetic algorithm represents excellent capability in multi-objective optimization.In this paper, genetic algorithm
is employed to the multi-objective optimization of system reliability.Genetic operators are modified based on the in-
pessimum layered genetic algorithm , and the inpessimum solution to the optimization problem is thus obtained .Then,
sensitivity analysis is carried out toshrink the solution space .By a comparison experiment , it is verified that the speed
and precision of the proposed algorithm is effectively improved

Analysis of the ARCH Effect of CNY Exchange Rate Expectation

Ren Zhao- zhang Ning Zhong- zhong

2004, 32(12): 83-88.

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The CNY NDF (Non-deliverable Forward)rate is used as a proxy for the CNY exchange rate expectation and the ARCH(Autoregressive Conditional Heteroskedastic)models are used to analyze the variation cha-racteristics of the CNY NDF rate .The analytical results show that the CNY exchange rate expectation has an ARCH effect , and there are high peak , fat tail , volatility clustering and asymmetric characteristics for the CNY NDF rate .These characteristics require a stable CNY exchange rate and a more flexible mechanism for the CNY exchange rate policy in order to deal with the appreciation and depreciation of CNY .A reasonable floating range is also needed and the CNY exchange rate mechanism should be improved step by step.

Relationship Between the Value Orientations of Employee in Different Groups and the Allocation Preferences

Liu Shan- shi Weng Sai- zhu

2004, 32(12): 89-93.

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The problem of multi-objective optimization has many sets of optimal solutions.The traditional method to solve the problem is to translate the multi-objective into several single objectives and then resolve the invert problemby the single-objective optimization technique .Unfortunately, this method has many inherited flaws.As a parallel algo-rithm , genetic algorithm represents excellent capability in multi-objective optimization.In this paper, genetic algorithm is employed to the multi-objective optimization of system reliability.Genetic operators are modified based on the in-pessimum layered genetic algorithm , and the inpessimum solution to the optimization problem is thus obtained .Then,sensitivity analysis is carried out toshrink the solution space .By a comparison experiment , it is verified that the speed.
and precision of the proposed algorithm is effectively improved.

Study on the Model of the Fatigue-loaded Vehicles in Guangzhou Trestle Bridges

Wang Rong- hui, Chi Chun, Chen Qing- zhong, et al

2004, 32(12): 94-96.

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Based on the survey of the traffic conditions at the Hengfu Road section of the Guangzhou Inner Ring Road, the load frequency value spectrum composed of daily transport vehicles was obtained by simplifying the ob-served load frequency value spectrum into a practical one composed of model vehicles according to the principle of e-quivalent fatigue damage .The fatigue-loaded vehicle model of Guangzhou trestle bridges was then set up on the basis of the simplified load frequency value spectrum.This model can be applied as a reference to the fatigue assessment and design of other trestle bridges in Guangzhou.

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