bluuebunny/crossref_metadata_2025 huggingface dataset:
The Preparation, Texture and Electrodeposition Mechanism of Reticular MnO2 Catalytic Materials with High Porosity
Authors: Yu Zhi Ming , Hu Jia Xiu , Zhao Jian , Niu Yun Song
Published: August 2011

The Ni-based reticular MnOx catalytic materials with high porosity and high specific area were prepared by the electrodeposition method. XRD and SEM were employed to characterize the phase structure and morphology of the MnOx films before and after heat treatment. The phase structure has changed from irregular amorphous structure to compacting crystal structure on the effect of heat treatment. The results show that the phase in the film is γ-MnO2after aging. The electrodeposition mechanism of MnO2has also been studied in this paper. MnO2was deposited by the hydrolysis reaction of Mn2+ in electrolyte and the disproportionation reaction of unstable Mn3+ions. A large number of hydrogen was released during the whole deposition process.
Distribution Character of Structural Stress for Aluminum Alloy Thick Plate
Authors: Wei Shao Jie , Liao Kai
Published: August 2011

Generation of structural stress in aluminum alloy thick plate is divided into three stages including the early, stable and late period using thermodynamics and elasticity theory. With FEM and mechanical state of materials, nonuniform plastic deformation is discussed, and distributions and characters of structural stress are analysized in each stage. Finally, experimental results agreed with date of the FEM. This truth demonstrated that mechanism of stress that changes in the process of thermal field works on formation of the final residual stress in the thick plate.
Microstructure Formation with the Elastic Interactions of Internal Stress and Applied Stress
Authors: Li Yong Sheng , Cheng Xiao Ling , Yu Yan Zhou
Published: August 2011

Microstructure formation under the applied strain for the alloys with different shear modulus and anisotropy were studied using the phase-field simulation. The uniaxial morphology depends on the magnitude of applied strain, the ratio of shear modulus and ratio of anisotropy between the precipitates and matrix. However, the morphology orientation depends not only on the sign and direction of applied strain, but also on the ratio of anisotropy and the ratio of shear modulus between the precipitates and matrix. The simulation results are helpful for the materials microstructure design and control by the combination of internal elastic stress and the applied strain.
Investigation of Initial Bubbles of CO2 Injected into Polymer Melt
Authors: Zeng Hao Hua , Wu Xiao Dan
Published: August 2011

Continuous extrusion foaming of CO2gas is an efficient method to produce microcellular. The CO2concentration in polymer melt is related to initial bubble morphology. Using video recording in this paper bubble interfacial morphology was studied when the gas was injected into polymer melt . The process of single bubble formation in the static and dynamic polymer melt includes three stages. Screw was more effective for gas breaking up and separating. When mixed in screw channel, and blent in the mixing segment, the dispersion, and diffusion rate of gas into polymer melt were increased largely.
Transient Analysis of Flow Field in Cylinder of an Engine
Authors: Xv Yan Fang , Su Tie Xiong , Cui Jun Jie
Published: August 2011

The study investigates the air flow in the tangent intake system of an engine utilizing the combined dynamic mesh technique. The whole intake system region of an engine is separated into six distinct zones, including inlet port, inlet valve, outlet port, outlet valve, combustion chamber and cylinder piston top, that every zone generates a desirable grid based on the adaptive function. The 3D simulations are carried out and the velocity and pressure fields are obtained inside the intake system. The analysis on the numerical results shows that the combined dynamic mesh can adapt to multi-boundaries in the intake systems, and can add cells where they are needed in the mesh. The simulation by such technique, compared with those by the single mesh, is able to be better resolved the flow features of intake system of an engine
Research on the Velocity Look-Ahead Algorithm in the NC System
Authors: Liu Jian Qun , Xu Dong , Wu Ji Rong , Xu Yang , Li Xiao , Huang Jian
Published: August 2011

Aiming at improving the interpolation efficiency without lowering the machining accuracy, the velocity look-ahead algorithm in the numerical control (NC) system is introduced. Firstly, the machining path’s transferring vector angle model is established, and then the conditions of direct transfer for the adjacent paths are also discussed. Secondly, based on the linear acceleration/deceleration control, the velocity look-ahead algorithm is put forward which can find the approximate-optimal velocity adaptively according to the maximum number of the look-ahead blocks and the geometric properties of the machining path. Finally, the acceleration/deceleration control in the consecutive micro-path can be realized, therefore, the high-speed and smooth transfer of feed-speed among machining path blocks can be achieved.
Analysis of Stresses for Cross-Ply Laminates with Multiple Matrix Cracks under Bending
Authors: Zeng Qing Dun , Ouyang Mao Hua
Published: August 2011

On the basis of the shear-lag theory, a layered shear-lag model was established to study the stress redistributions of cross-ply laminates with multiple transverse matrix cracks in the 90º ply under bending. The present results are in a good agreement with variational solutions and finite element results and show that approximate solutions of stress distributions for cross-ply laminates with transverse cracks under bending can be obtained by using a shear-lag method. The present paper therefore affords a new way or method for studying the stress redistributions and failure mechanism for cross-ply laminates with flaws under bending.
Structure and Tensile Properties of Nano-Filament Knitted Fabrics by Alkali Treatment
Authors: Li Yue , Joo Chang Whan
Published: August 2011

Knitted fabrics have been widely used in different fields due to their high strength and elastic properties. However, these can only be used in limited applications due to poor liquid absorption owing to the large pore size of knitted fabrics. This study is focused on the structural characteristics of micro- and nano-filament warp as well as weft knitted fabrics. Nano-filament fabrics are manufactured by means of alkali treatment. Filament diameters are significantly reduced according to SEM micrographs. The decreased porosity of nano-filament fabrics indicates that nano-filament knitted fabrics possess excellent water absorptive capacity due to capillary action in the fabrics. Tensile behaviors of knitted fabrics in the wale and course directions are investigated as well.
Effect of Grain Rotation on the Strain-Softening Behavior in Nanocrystalline Materials
Authors: Zhou Jian Qiu , Wang Ying , Zhang Shu
Published: August 2011

We postulated a softening model involving grain rotation that results in diffusion-accommodated grain-boundary sliding. This numerical model was used to compute the proportion evolution of grains within shear bands and was also employed to predict the softening of nanocrystalline materials considering non-homogeneous plastic deformation due to shear bands. The effect of softening mechanism for total stress-strain relation and the grain size and mean maximum Schmid factor effect was also considered in our model.
Evolution of Microstructures and Mechanical Properties of Sr and Ca Containing Mg-4Al Alloy during Annealing Heat Treatment
Authors: Bai Jing , Sun Yang Shan , Xue Feng
Published: August 2011

Microstructures, mechanical and creep properties of as-cast and as-annealed Mg-4Al-2Sr-1Ca (AJX421) alloy were investigated. The as cast microstructures of the alloy consists of the α-Mg, lamellar eutectic Mg2Ca and bulky Mg-Al-Sr phase. After annealing at 400°C, lamellar eutectic tended to be spheroidised and the continuous interphase network breaks up gradually, meanwhile, C14-Mg2Ca completely transforms to C15-Al2Ca. These results in obvious decrease of creep property. It is proposed that the continuous network distribution of compounds paly a major role in restricting the creep deformation of Mg-Al alloy at elevated temperatures, and the grain boundary sliding is an important creep mechanism for the alloy studied.
Study on the Similar Creep Behaviors and Mathematical Laws of 1Cr18Ni9Ti under Low Stress Repeated Impact
Authors: Chu Cheng Yuan , Shi Shi Hong , Fu Ge Yan , Xu Mei
Published: August 2011

1Cr18Ni9Ti specimens were observed the plastic deformation by the method of coordinate grid under the low stress repeated impact test. And it found some phenomenon is similar to the creep phenomenon ,so the paper call it “repeated impact creep”. Proceeding from the theory of creep deformation, the deformation law of the specimens was analyzed and the relevant mathematical model was established.Finally, it found that the strain rate of repeated impact creep is decreased by the increase of impact times and the increase of layer’s depth.
Effect of Prestrain on the Fatigue Crack Initiation life of X60 Pipeline Steel
Authors: Chen Mei Bao , Jiang Yu Rong
Published: August 2011

It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation was used to imitate the defects of the part of material and the U-notch specimens were used to investigate the fatigue crack initiation life of X60 pipeline steel after pre-tension straining with ductile deformation of 0,5%,10% and 15%. Test results show that the prestrain had apparent straining hardening effects, but decreased the plasticity of pipeline steel. The prestrain prolonged the fatigue crack initiation life, and increased resistance coefficient and equivalent stress threshold of the fatigue crack initiation.
Friction and Wear Behavior of Polypropylene/Montmorillonite Intercalated Nanocomposites
Authors: Chen Kui , Zhang Tian Yun , Wei Wei
Published: August 2011

Polypropylene/organo-montmorillonite (PP/OMMT) composites were investigated by XRD. Friction and wear behaviors of this composites sliding against GCr15 stainless steel were examined on M-2000 text rig in a ring-on-block configuration. Worn surfaces of PP and its composites were analyzed by SEM. The result shows that PP macromolecule chains have intercalated into OMMT layers and form intercalated nanocomposites. With the increase of mass fraction of OMMT, both wear rate and friction coefficient of composites first decrease then rise. With the increase of load, from 150 N, 200 N to 250 N, wear rate of composites increases, while friction coefficient reduces. The wear mechanisms of composites are connected with the content of OMMT. Composites were dominated by adhesive wear, abrasive wear and adhesive wear accompanied by abrasive wear respectively with the increase of OMMT content.
RFID-Based Thermal Bubble Non-Floating Type Accelerometer with Semi-Cylindrical Chamber and Filled with Xenon Gas
Authors: Lin Jium Ming , Chang Po Kuang , Lin Cheng Hung , Zhang Qi Kun
Published: August 2011

This research proposes a wireless RFID-based thermal bubble accelerometer design, and relates more particularly for the technology to manufacture and package it on a flexible substrate. The key technology is to integrate both a thermal bubble accelerometer and a wireless RFID antenna on the same substrate, such that the accelerometer is very convenient for fabrication and usage. In this paper the heaters as well as the thermal sensors are directly adhering on the surface of the flexible substrate without the traditional floating structure. Thus the structure is much simpler and cheaper for manufacturing, and much more reliable in large acceleration impact condition without broken. Furthermore, the molecular weight of xenon gas is much larger than carbon dioxide, thus the performance of the accelerometer will be increased. In addition, the shape of the chamber is changed as a semi-cylindrical one instead of the conventional rectangular type. Comparisons of sensitivity and response time are also made; one can see the performances of the proposed new design with either semi-cylindrical chamber or filled with xenon gas are better.
Adaptive Backstepping Control for an Interior Permanent Magnet Synchronous Motor Servo System
Authors: Lin Li , Tang Hong Wei , Tang Jie
Published: August 2011

This paper presents a nonlinear adaptive backstepping current hysteresis speed controller which can be used in both the constant-torque region and the field-weakening region for an interior permanent magnet synchronous motor (IPMSM). By using the proposed method, the adjustable speed range can be extended to 4 times that of the base speed. In addition, the d-axis current is suitably adjusted to increase the output torque of the IPMSM. Simulation results show that the implemented system has satisfactory performance, including good transient responses, good load-disturbance-rejection responses, and good tracking ability.
Research and Application of Phase-Sensitive Protection in Load Control Center
Authors: Xu Chun Yu , Zheng Li Jun , Song Jian Cheng , Gao Yun Guang
Published: August 2011

The malfunction of short-circuit protection became increasingly serious in the fully mechanized face casused by large power equipment, more kind of loads and long distance power. According to the field requirements, the electrical characteristics between motor starting and three-phase short-circuit are compared, the phase-sensitive protection circuit combining current signal amplitude with power factor is designed, the protection data is tested and the protection characteristic is analyzed. The phase-sensitive protection circuit has been uesd in KJZ-4000-10（6）/3.3 flameproof and intrinsically safe load control center. The circuit is stable, sensitive and reliable. It has been proved that the short-circuit protection of power in underground is reliably realized.
A Study on 3D Modeling of City Buildings Based on CSG
Authors: Xu Cheng Fu , Liu Li Ping , Wang Yu Jian
Published: August 2011

This paper firstly introduces the frame system of digital city and the process of 3D city modeling, and discusses the method of CSG modeling of buildings. This method extracts CSG primitives according to building features, then makes geometric transformation and regular Boolean operation on these primitives to form 3D model of buildings. The process of modeling and inner topological relationship of buildings can be represented by this method.
Design and Research on the Test and Analysis System for the Proportional Relief Valve Characteristics
Authors: Liu Chuan Xi , Meng Xian Ju
Published: August 2011

With economic and practical as a starting point, we design and develop the hydraulic platform for proportional relief valve characteristics and automatic test and analysis system that based on virtual instrument and MATLAB software. A new modular design (MD) has been applied to test method for proportional relief valve characteristics, which realized the real-time data acquisition for multi-path pressure signal of automatic measurement & control and hydraulic system for steady state and dynamic state of DBE series proportional relief valve, and conducted analysis such as time domain, frequency domain, visualization and so on to collected data, obtained rather valuable test data and characteristics conclusion. Experiments show that this system has reasonable design and stable performance, enhances the test precision, improves the test method, enriches the analysis means and has good cost performance and research practicability.
Study on the Angle of Stationary Crescent for Radial Compensation of Inner Mesh Gear Pumps
Authors: Zhang Jian Zhuo , Li Kang Kang , Gao Meng , Zhu Tian Zi
Published: August 2011

Abstract：The working mechanism of the stationary crescent for radial compensation in the inner mesh gear pumps was studied in this paper. The force of the top and bottom stationary crescent in one hydraulic pressure changing cycle was analysed. The pressure distribution on the top and bottom stationary cressent in different positions and the hydraulic force at the x，y direction were determined.Under the condition of the force of the top and bottom stationary crescent is least and the two stationary crescents stay close to the tooth crest of internal gear and external gear to form radial seal，the angle of the end of the top stationary crescent in the high pressure area and the fixing angle of the seal stick was optimized. Experiment results show that the volumetric efficiency is 0.94 when the outlet pressure reach to 30Mpa, and the oil temperature is less than 55°C, there is no abrasion on the two sationary crescents and the tooth crest.
Design of a DSP System Based on FPGA
Authors: Hu Ju Fang , Xiong Chun Ru , Hu Hao , Zhong Run Yang
Published: August 2011

This paper proposes an innovative methodology to design a DSP (Digital Signal Processing) system using FPGA (Field-programmable Gate Array). There are several main components in this system, including A/D sampling unit, FFT processing unit and control unit. A/D sampling and FFT processing units utilize the Nios processor in FPGA as controller. Control unit uses EP1C20 FPGA chip from ALTERA as FFT processing unit so as to manage the FIFO operations. This unit can handle 128 FFT operations. This system design approach is tested on Matlab. The results indicate that the calculation speed is much faster than common DSP manner.
An Algorithm and Design for RFID Velocity Measurement Based on Least Square Method
Authors: Jiang Lin Ying , Zhang Heng , Tan Han Qing
Published: August 2011

This paper comes up with an algorithm and application for velocity measurement based on RFID technology. This measurement can reduce the cost of velocity-measuring system to a great degree, and improve the accuracy of velocity measurement on the basis of the algorithm.
Study on Lining Board with Bimetal Liquid Composite Casting
Authors: Rong Shou Fan , Zhu Yong Chang , Shi Chun Yan , Tian Chun Ying , Yu Feng , Sun Jian Bo
Published: August 2011

The effect of chemical constitution, casting technique and heat treatment parameters on microstructure, properties and wearing resistance of the bimetal composite were primarily researched by SEM, EDAX, TEM etc.. The results showed that the higher impact toughness at bimetal combination region than corresponding part of the high carbon steel was obtained. The impact toughness was 23J/cm2 and the hardness of resistant surface was HRC59. The high carbon steel region initiated the impact fracture, however its abrasion resistance was substantially improved over double than Mn13.
Application and Analysis of Long-Distance EPON in Transmission Lines Monitoring System
Authors: Huang Hui , Zhang Hao
Published: August 2011

Ethernet Passive Optical Network (EPON) has been widely used in the Smart Grid. However, the overlay radius of EPON system is generally a 20 km, which has become the obstacle of application of EPON in Smart Grid.This paper introduces the advantages of EPON and analyzes the need for long-distance EPON of t Transmission Lines Monitoring System. And also this paper analyzes the factors affecting the long-distance transmission of EPON. Then this paper discusses the implementation of long-distance EPON and proposes a scheme of achieving communication network of Transmission Lines Monitoring System based on long-distance EPON.
Research of Manufactory Technology for the Hammer of Single Roll Crusher
Authors: Huang Ping , Zhou Lan Hua , Yang Shao Li
Published: August 2011

Considering the condition that the longevity of hammerhead of single roll crusher is short, both technologies of welding stick with high chromium cast iron and prevent-split board were used to overlay-weld the hammerhead unitarily. The results are found that the longevity of the hammerhead improved is 8 times longer than that before the experiment.
Effect of Structure on the Performance of Electrostatic MEMS Actuator
Authors: Hu Fang Rong , Chen Man E , Xiao Jing , Yu Wei , Niu Jun Hao , Nie Kun
Published: August 2011

Four types of MEMS actuators are presented in this paper. The effect of structure on three major performance parameters of these actuators, such as resonance frequency, pull in voltage and stroke, are studied by FEA and compared with each other. The result shows that, on the condition of the same spring length and the same spring width , O-shape actuator have the largest stroke and pull in voltage, but that of L-shape actuator is the smallest.
A Conceptual Framework for Ensuring the Implementation of the Public Warehouse Based on RFID
Authors: Cao Wei , Jiang Ping Yu
Published: August 2011

When the idea of service has redefined the way that a warehouse is operated and facilitated the emergence of public warehouse as a new logistic mode, in recent years, the maturity of RFID technology and its applications have brought deeply impact to the warehouse once again. In this paper, a conceptual framework about how to use RFID in the public warehouse is proposed. The main functions of the framework, working flow of a public warehouse and its management style of are illustrated. At last, some key enabling technologies are described in detail, that is, RFID tag and reader configuration, task pool model and task implementation mathod.
A Contactless Mobile Payment Method Based on Security TF Card and NFC Technology
Authors: Li Ping , Zhou Qing Lei , Liu Yang , Zhao Dong Ming
Published: August 2011

The paper presents a contactless mobile payment method based on security TF card and NFC technology, with which we can use the security TF card, instead of a special SIM card that support SWP protocol, as a security module to store the user’s important information (e.g. transaction data) in mobile payment. And because security TF card can be distributed by non-telecom operators, the method can obtain a more extensive support by units and institutions other than telecom operators. then it is meaningful to the development of NFC technology.
Tracking and Analysis of Two-Dimensional Saddle Node Bifurcation Boundary in Wind Power System with Reactive Power Compensation of STATCOM
Authors: Ma You Jie , Liu Jin Hua , Zhou Xue Song , Li Ji
Published: August 2011

As a new dynamic reactive compensation devices, static synchronous compensator (STATCOM) has better reactive power compensation effect such as small in size, capacity, continuous adjusting, fast response and economic performance compared with SVC. It is suitable to be used in large-scale wind farm to improve the voltage stability of wind power system. With the help of ideas and methods in conventional electric power system to calculate the two-dimensional parameter bifurcation boundary, the node voltage two-dimensional saddle-node bifurcation boundary of wind power system was calculated by using wind farm active power inject(Pin ),STATCOM parameters KMdc and Vrefdc as bifurcation control parameters. And on the basis of this analysis, the laws of wind power system voltage stability affected by active power and STATCOM parameters were obtained.
Research on Open Architecture NC System of Blade Polishing Machine Based on PMAC
Authors: Li Ren Jiang , Wang Xin
Published: August 2011

This paper based on a kind of hybrid machine tool. The structure of hardware and the application of PMAC in the control system of the machine are introduced. This system uses double CPUS mode and the software is developed in Windows platform. Besides, the interpolation strategy and the interpolation algorithm for the machine are proposed
Development of a STEP-NC Controller for 5-Axis Machining of NURBS Surfaces
Authors: Li Xia , Liang Hong Bin
Published: August 2011

In conventional machining of free form surfaces, incomplete information exchange between CNC and CAD/CAM results in many limitations need to be rectified. In the paper, a new structure of CNC based on STEP-NC is proposed. A 5-axis real-time interpolator for NURBS surfaces machining is realized. A STEP-NC controller has been developed, which is a software modular CNC system. The CNC system has been installed on a tilt-rotary type 5-axis machine tool. The milling experiment has been performed.
Emergency Policy for Perishable Products Supply Chain when Nodes Fail
Authors: Liu Kai Fei , Liu Xiao
Published: August 2011

Emergency management is becoming more and more important with the vulnerability increasing in global supply chain. An effective policy which is emergency strategy stock based for perishable supply chain emergency scheduling with a failed produce node has been proposed. Mixed integer programming model was build under the inventory policy of perishable products which include both of raw materials and finished products. The simulation results show that our policy of the model is effective, and could solve these problems completely.
Simulation of the Parking Behaviors in a Shopping Mall of Dalian
Authors: Liu Li , Dai Ting , Dou Yi , Huang Hai Ping , Huang Jun Jie , Ye Ning
Published: August 2011

The best is to read these instructions and follow the outline of this text. This paper models and simulates the parking behaviors in a main commercial area in Peace Plaza, Dalian City. By analyzing the simulation results, we propose a feasible plan to solve the problem that some customers cannot find a parking space and there are too many illegal parking behaviors in this area. The simulation shows that it can effectively reduce the number of cars that can’t find a parking space or illegally park by the road.
Influences of Smoke Exhaust Effect by Setting Atria Buffer Zone in Straight Corridor of Building
Authors: Zhang Wei , He Jia Peng , Li Jing Xian
Published: August 2011

In high-rise building fires, a great deal of fresh air will be sent into the fire floor when pressurization is taken. Smoke is diluted by the fresh air, and the efficiency of mechanical smoke exhaust is reduced. The assumption that set atria buffer zone in straight corridor of high-rise building is put forward, and mathematic model of smoke flow in high-rise building. The results show that, for straight corridor, setting atria buffer zone the efficiency of mechanical smoke exhaust is about 3.6% higher than which atria buffer zone is not set, and smokeless zone is formed in the corridor nearby atria, and it is helpful to escaping from fire floor for people.
Hydraulic Calculation Method Study of Branch Shape Water-Injection Pipe Network Based on Binary Tree
Authors: Wei Li Xin , Wen Jiang Bo , Zhang Lu Ying , Xu Yan Chun , Li Peng
Published: August 2011

On the basis of analyzing process and structure characteristics of branch shape water-injection pipe network, this paper established a hydraulic calculation method of branch shape water-injection pipe network based on binary tree. This method has many advantages, such as calculation speed is fast, occupying less memory, having high calculation accuracy, and so on. According to it, this paper compiled a computer program and presented an actual example.
Study of Key Parameters of Braking Energy Recovery Scheme for the Underground Loader Basing on Man-Machine Engineering
Authors: Yang Ling Xiao , Yang Zhong Jiong , Zhu Li Jun
Published: August 2011

Considering frequent braking characteristics in working process of the Underground Loader, a braking energy recovery scheme for Underground Loader is put forward, on this basis, a corresponding mathematical model is established. Moreover, simulation study in MATLAB/Simulink on the three key parameters (accumulator volume, charge pressure and hydraulic pump discharge) which affect the efficient of energy recovery are carried out. At last, several key parameters of braking energy recovery scheme of Underground Loader are optimized basing on Man-Machine Engineering.
Three-Dimensional Interactive Simulation of Anschütz Gyrocompass Based on VRML
Authors: Wu Jian Hua , Fang Xun , Li Hao
Published: August 2011

Gyrocompass is an important instrument which provides course to vessels, but its complex three-dimensional structure and principle of pointing towards the North is a bottleneck of studying gyrocompass. The master compass of Anschütz 4 gyrocompass are simulated by virtual reality modeling language VRML, so that using three-dimensional interactive to show the structure of the gyrocompass and the work principle is implemented and learners will have a direct cognition to each part of the gyrocompass and its work principle. The realization process of simulation in the virtual reality environment is described in detail and the relevant source codes is given.
Dynamical Modeling, Simulation and Analysis for Voltage Regulation System of Hybrid Excitation Doubly Salient Generator
Authors: Dai Wei Li , Yan Yang Guang , Fei Jun Tao
Published: August 2011

Hybrid Excitation Doubly Salient Generator (HEDSG) with parallel magnetic circuits is performed in this paper, and the main flux in the machine is determined by the permanent magnet and the field coils. The structure and working principle of the generator are described in detail. In order to build the voltage regulation system of HEDSG, a bidirectional excitation voltage regulator is proposed, which could keep the output voltage of the generator stable by adjusting the field current. The two control loops including excitation current feed-forward and output voltage feedback loops are applied in the voltage regulator. Subsequently, the mathematical model of the voltage regulation system is constructed after the transfer function of the generator is obtained by using system identification method. Moreover, in order to realize the field current bidirectional flow, bipolar pulse width modulation is also applied in the regulator, and the control parameters influencing on the output voltage are analyzed. Lastly, the prototype of bidirectional excitation voltage regulator is designed and theoretical analysis and simulation results are verified by the stable and dynamic experiments.
Analysis of Petersen Coil Application in Electrical Distribution Networks
Authors: Sun Yan Zhou , Hu Kun , Ren Wan Ying
Published: August 2011

The purpose of this paper is to show the development of Petersen coil and compensated network in the high voltage power distribution networks of China. There were two correlative questions when the Petersen coil is used, one is to restrict the series resonance under normal conditions, and the other is to choose the grounded line correctly. The KD-XH Coil, which uses the servo-control adjustment, has high response speed (less than 5 milliseconds), continuously adjustable current output (from zero to rated value) and linear V-A characteristic, and shows high accuracy in applications as soon as the grounding fault occurs.
Simultaneous and Sequential Fermentations with Saccharomyces cerevisiae DJ02 and Lactobacliius acidophilus WS in Pear Wine
Authors: Zhang Da Wei , Dong Wen Bin , Zhang Dan , Jin Lei , Zhang Jie , Li De Ming , Li Hui Dong
Published: August 2011

The two controlled inoculation procedures of simultaneous and sequential fermentations with Saccharomyces Cerevisiae DJ02 and Lactobacliius acidophilus WS were studied in pear wine. The sugar consumption and ethanol product were delayed in the course of simultaneous fermentation contrary to the single fermentation. However in the sequential fermentation the effect was less than the simultaneous fermentation. In this work the function of malic acid degradation in the sequential fermentation was better than the simultaneous fermentation. The pH value of the pear wine came to 3.9 after the sequential fermentation. The change tendency of the yeast population after adding Lactobacliius acidophilus WS was similar to the yeast single fermentation in the simultaneous and sequential fermentation. But the cell population was went down in the course of the fermentation. The population of Lactobacliius acidophilus WS in the course of the two kinds of fermentation methods showed no significantly differences.
Preliminary Study on Dissolved and Colloidal Organic Carbon in Tidal Creek of Chongming Dongtan
Authors: Huang Wen Dan , Zheng Xiang Min , Zhou Li Min
Published: August 2011

Water samples were collected in the northern, eastern and southern tidal creeks of Chongming Dongtan in January, 2009. The samples were passed through 0.45μm pore size GF/C glass fiber membrane and colloid was isolated by mini tangential flow ultrafiltration (TFF) with ultrafiltration membrane pore-size of 1kD (1kD=1 000 Daltons). Then the content of organic carbon was tested by TOC II. Results show that the contents of dissolved and colloidal organic carbon (DOC and COC) in the northern creek are higher than the eastern and southern tidal creeks of Chongming Dongtan, and the concentration of DOC decreased from high tidal flat to low tidal flat. Hydrodynamic and vegetation are the important factors to affect the content of COC in tidal creek water of Chongming Dongtan.
Modification of Microstrucure and Residual Stress on Friction Welding Surface of Titanium Alloy by Water-Jet Cavitation Peening
Authors: Ju Dong Ying , Fu Xin Mao , Na Shun , Han Bing , Deng Xiao Hu
Published: August 2011

Water jet cavitation peening is applied to improve the strength and mechanical properties of the friction-welded joints of titanium alloys. Scanning electron microscopy observations of the microstructure of the welded joints and welded area before/after water jet cavitation peening confirm slip dislocation at the microstructure near the surface of the specimens. The residual stress on the surface of the welded joint is measured by X-ray diffraction. The results indicate the effect of peening time on the strength of compressive residual stress.
Kinematic Analysis of A Novel 2-UPU/2-URU Parallel Mechanism
Authors: Li Shi Hua , Wang Zhi Song , Yu Chang Cheng , Gong Wen
Published: August 2011

Abstract. In this paper, a novel type of 2-UPU/2-URU asymmetric parallel mechanism is put forward, the degree of freedom and kinematics characteristics of the mechanism is analyzed. Firstly, based on screw theory, the degree of freedom of the mechanism is analyzed by using modified Grübler-Kutzbach formula of Degree of Freedom, the method is ingenious and simple. Then the kinematics analysis is done. Finally, the velocity and acceleration of the mechanism is analyzed by combining kinematic influence coefficient theory with imaginary mechanism method, and draw the velocity and acceleration performance curve of the mechanism with the MATLAB. This paper lays the foundation for further research of the parallel mechanism.
Design and Experiment of the Pneumatic Plate-Type Vegetable Seeder
Authors: Xia Hong Mei , Li Qing Rong , Li Zhi Wei
Published: August 2011

Structure plan of a new type of pneumatic plate-type vegetable seeder was put forward, and virtual prototype of the seeder was established in the paper. By kinematics simulation and analysis, L-shape arm length and minimum distance between metering device and cell plug tray were optimized. The machine control system and air pressure switch system were designed in detail. Results of orthogonal test show that, the main influence factor for single-seed rate and empty-seed rate is sowing efficiency, the second is diameter of suction hole, next is relative pressure, the minimum is interaction between those factors. The main influence factor for multi-seed rate is diameter of suction hole, the second is relative pressure, next is interaction between factors, the minimum is sowing efficiency. The best seeding effects can be achieved under the condition of 0.9 mm suction hole diameter, -4.5 kPa relative pressure, and 200-tray per hour sowing efficiency. The single-seed rate can be up to 93.59%, the empty-seed rate is 1.25%，and the multi-seed rate is 5.16%。
Giant Die Forging Press Machine Main Circuit Electromechanical Hydraulic Servo Control System Modeling and Simulation
Authors: Yang Ji Dong , Chen Xin
Published: August 2011

This paper research on an electromechanical hydraulic mixture control system used in large scale die-forging press, based on the national major science and technology project (2009ZX04005-011). This mixture control system used in press machine accomplishes pressing, pressure-keeping, return. The control system uses hydraulic oil to control three-position five-path slide valve as hydraulic system main valve, for drive system of giant die forging press is characteristic of ultrahigh pressure and large flow, high power. This control system consists of two parts: firstly, establishing electromechanical hydraulic mixture control model by adding electronics and feedback section to servo slide system. Secondly, combining existing slide control hydraulic cylinder model and server slide system form main circuit closed-loop control system. The last but not least, Computer simulation was conducted by matlab got the ideal control curve.
Enhancement of a Fault Measure for AMSs Using Probabilistic Timed Automata
Authors: Huang Yi Sheng , Chiang Ho Shan
Published: August 2011

A novel approach for probabilistic timed structure that is based on combining the formalisms of timed automata and probabilistic automata representation of the system is proposed. Due to their real-valued clocks can measure the passage of time and transitions can be probabilistic such that it can be expressed as a discrete probability distribution on the set of target states. The usage of clock variables and the specification of state space are illustrated with real value time applications. The transitions between states are probabilistic by events which describe either the occurrence of faults or normal working conditions. Additionally, the passage of discrete time and transitions can be probabilistic by mean of the theory of expectation sets to obtain a unified measure reasoning strategy.
The Influence Analysis of Parameter Errors for Multi-Legged Walking Robot
Authors: Zou Jing Chao , Wang Liang Wen , Zhang Xiao Hui , Li An Sheng
Published: August 2011

Because the structural and motion parameters errors, when the robot move in the ideal situation, actual posture of the robot is likely to deviate from its required position. Based on the discussion of forward kinematics, which is calculating the influence of error sources on the posture error of robot, is researched in this paper, and an example is used to explain. The effect of each parameter on posture error can be evaluated by analyzing the results of example. The designer can make different error control method for each parameter according to the influence of them.
Development on Inspection System for Gear’s Dimension Based on Machine Vision
Authors: Jin Wu Yin , Du Hong Ru , Zhang Xia , Hu Jing Ping
Published: August 2011

A noncontact inspection system for gear based on machine vision is developed in this work, according to the mathematical model of lens distortion; the calibration of the camera was realized by the MATLAB calibration toolbox, obtained the distortion coefficients, by which the pixel is proofread. After then the key parameters of gear could be automatically acquired with proposed algorithm. In this work, the algorithm is applied to a practical case of a standard spur gear; the experimental results reported here confirm the effectiveness of the approach.
An Efficient VMIMO Scheduling Scheme for Wireless Sensor Networks
Authors: Long Cheng Zhi , Luo Jian Ping , Chen Hui
Published: August 2011

This paper gives an efficient VMIMO scheduling scheme for wireless sensor networks(WSNs) with a node selection algorithm. Scheduling communication scheme with feedback channel is proposed in this paper. Using the feedback channel, channel state information (CSI) could be return to transmitting cluster. Then the “better” node could be selected to participate in cooperation. Simulation results show the efficient of the proposed Scheme in energy saving.
Mechanical Analysis of Steel Beam and Steel-Concrete Combined Section Pavement in Long-Span Hybrid Girder Bridge
Authors: Zhong Ke , Hu Jing , Zheng Bin
Published: August 2011

Firstly the pavement compound system model of steel beam and steel-concrete combined section are established based on structure characteristics of long-span hybrid girder bridge, and the worst loading locations and their characteristics of two beams are obtained. Then, mechanical responses of pavement under the worst loading locations are analyzed to compare mechanical control indices and stress distribution of two beam model. parameters and suggestions are provided for formulation of standards of long-span hybrid girder bridge pavement, at the same time theoretical basis is and selecting pavement materials and pavement structural optimization design.
Toward Risk Assessment of Explosion Hazard: Experimental Determination of Flame Fractal Dimension
Authors: Takeda Daisuke , Kim Woo Kyung , Wada Yukari , Kuwana Kazunori , Mogi Toshio , Dobashi Ritsu
Published: August 2011

Quantitative risk analysis is a method to evaluate risk and to identify areas for risk reduction. The final goal of our study is to propose an effective method for risk assessment of explosion hazard. To achieve the goal, a phenomenon that influences the consequences of explosion is first identified: self-turbulization and resulting acceleration of expanding flame during explosion. The fractal dimension is then identified as the key parameter that characterizes the phenomenon. Since the previous method to determine fractal dimension relies on large-scale explosion experiment, it has not been easy to determine fractal dimension. This paper demonstrates the possibility of determining fractal dimension by analyzing flame images of small-scale experiment, which might significantly reduce the cost of risk assessment of explosion hazard.
Fabrication and Electrical Properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12 Bi-Layer Composite Ferroelectric Thin Films
Authors: Yang Song Bo , Tang Ming Hua , Wang Guo Yang , Jiang Bo , Xu Hua Yu
Published: August 2011

The microstructure and electrical properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12bi-layer composite ferroelectric thin films deposited on Pt/Ti/SiO2/Si using two successive spin coatings were investigated. It shows the pores in Bi3.5Nd0.5Ti3O12(BNT) films were effectively suppressed by the presence of P(VDF-TrFE) copolymer films by SEM. The ferroelectric, leakage and dielectric properties of the thin films with different thickness ratio of P(VDF-TrFE) and BNT thin films were measured. With increasing the thickness of P(VDF-TrFE), the remnant polarization, coercive electric field, leakage current density and dielectric constant of thin films were all decreased (except pure P(VDF-TrFE) thin film). Results indicate that the key electrical properties were improved effectively by a little loss of the remnant polarization, which infers potential application in the filed of ferroelectric memory.
A Rapid Cam Design and Manufacturing System and its Verification
Authors: Han Liu , He Ping
Published: August 2011

A rapid cam design and manufacturing simulation system is developed. The system consists of some modules which can be easily extended or updated. In the design module, the profile of disc cam is generated by defining some parameters – rise allowable pressure angle, return allowable pressure angle, the radius of curvature of cam profile etc. And the kinematics analysis of cam is also calculated in this module. Then the profile is transferred into Catia for generating a three dimensional geometry of the cam, and NC program is generated. Last, the NC program is verified by Yulong NC simulation system.
Experimental Study on the Failure Criterion for Brittle Materials in Compression
Authors: Ran Xu , Zhu Zhe Ming , Tang Hao
Published: August 2011

The mechanical behavior of multi-cracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, based on the previous theoretical results of the failure criterion for brittle materials under compression, experiment study is implemented. The specimens are square plates and are made of cement, sand and water, and the cracks are made by using a very thin film (0.1 mm). The relations of material compressive strength versus crack spacing and the lateral confining stress are obtained from experimental results. The experimental results agree well with the failure criterion for brittle materials under compression, which indicates that the criterion is effective and applicable.
Determination of the Optimum Fitting Probabilistic Distribution for Fracture Toughness in Small Sample Size
Authors: Liu Wen Lin , Yang Ri Jie , Mu Zhi Tao , Wang Xiu Xia , Yu Da Zhao
Published: August 2011

Plane strain fracture toughness is an important mechanical performance index for damage tolerance design, so how to obtain this value through test deserves consideration. In this paper, the ductile fracture toughness test was performed. It was difficult for the specimen with big dimensions in the case of plane strain to be carried out through ordinary testing machine with lower capacity because of the higher fracture toughness value of the material, that it was attained indirectly for plane strain fracture toughness value by the way of ductile fracture toughness test and pertinent formula calculation if proper specimen selected. The fracture property tests according to the corresponding standard were conducted. The compact tension specimens were obtained from the main rotor butt of a helicopter in service. Based on the single specimen measuring ductile fracture toughness method, the experiments of measuring the ductile fracture toughness were carried out. A method was given to determine the optimum fitting probabilistic distribution function of fracture toughness in the small sample size. The statistic results show that the optimum probabilistic distribution function of ductile fracture toughness is the Extreme Maximum. Value distribution. The following factors were taken into account, the linear relative coefficient, total fit effect probability relative coefficient, consistency with the relevant fatigue physics and tail most importantly, safety of design evaluation. The shape parameter, scale parameter, and location parameter are -1.1231, 860.53, 6036.4, respectively. The statistical variation coefficient is 11.22%. The result shows that there is a large risk probability for a definite value to fracture toughness only with one or two pieces of samples according to the test.
Alkali Metal and Alkaline Earth Encapsulated Silicene-Like Nanotubes
Authors: Zhang Chuan Hui , Ran Qiong , Shen Jiang
Published: August 2011

The structural stability and electronic properties of silicene-like nanotubes by metal atoms encapsulated were studied by first-principles. The calculations demonstrate that all the structures of nanotubes are stable, expect beryllium doped. Some nanotubes are semiconductor with small value of band gap while others are conductor, because the interaction and hybridizations decrease the band gap. Our electronic structure analysis shows that metal atoms gain electrons and Si atoms lose electrons as a whole, some electrons transferred from Si to metal atoms. We hope that our calculations will provide help to further experimental studies.
Research on Micro-Driver for Minitype USM
Authors: Yu Pu , Li Jie , Zhou Lin Qi
Published: August 2011

In this paper, a novel driving scheme using non-sinusoidal periodic signal is proposed, which is based on the driving principle of ultrasonic motor (USM).The PWM signal is generated by a micro-controller and the voltage is enlarged to 70v by a BOOST circuit. It is suitable for minitype USM using low voltage. A micro-driver with the dimension 2.1×2.3cm2 is constructed to drive a two-phase micro (2mm) USM and the motor operates well. It is proved that the proposed circuit is both feasible and reliable for the drive of low-voltage minitype USM, and the proposed scheme is helpful for the promotion of ultrasonic motor.