bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Objective Optimization Strategy for Cutting Parameters Based on Controlling Face Milling Distortion
Authors: Tang Dong Hong
Published: March 2012

Machining distortion analysis and control are the kernel problem in manufacturing industry recently. This paper take face milling as research object, a finite element model for 3D milling process is set up based on some key techniques including cutter feed trajectories representations, cutter tooth-workpiece engagement model etc; Then the optimum LS-SVM model which can express the transitive relationship between cutting parameters and distortion error is set up; The cutting parameters optimization model based on controlling the machining distortion is founded by seeing the optimum LS-SVM model as the main objective function, meanwhile, an effective multi-objective optimization algorithm is proposed by coupling particle swarm algorithm and gray relevancy analysis, this algorithm can change the multi-objective optimization problem into optimizing the gray relevancy value effectively. As an example, the feasibility of proposed machining distortion controlling approach is verified.
Operational Modal Analysis of Broaching Machine
Authors: Lin Lv Gao , Ying Shen Shun , Chen Shu Qiong , Lv Xiao Tian
Published: March 2012

Modal parameters for LG51SH broaching machine from operational responses are studied to examine the dynamic properties of mechanical structure. The operational modal is analyzed using PolyMAX method with responsive data of key point in broaching machine, which is excited in practical broaching operation and tested by LMS SCADAIII-105 system. The identified steady state modal, representative modal shape, modal damping ratio and natural frequency in broaching are presented. The test and analysis result shows that there are natural frequency of 38Hz and 192Hz, which are close to multiple of the fundamental frequency of cutting force in broaching, 6Hz, therefore, reasonable cutting velocity should be adopted to void producing fundamental frequency of cutting force in broaching.
Optimization of Electrical Discharge Machining Process Parameters Using Desirability Approach
Authors: Sengottuvel P. , Satish Kumar S. , Dinakaran D.
Published: March 2012

Inconel 718 is a high nickel content super alloy having high strength at elevated temperatures and resistance to oxidation and corrosion. EDM process has many advantages over traditional manufacturing process during the machining of inconel 718. In this study experiments were conducted based on the L16 orthogonal array on inconel 718 material using tungsten-carbide (W-C) electrode tool material with kerosene as a dielectric fluid to determine the optimum EDM parameters along with circle(C), square(S), rectangle(R) and triangle (T) tool geometry which contribute to material removal rate (MRR), tool wear rate (TWR) &surface roughness (SR) in machining of inconel 718. Data were optimized using Desirability approach technique. Experimental results show that the current and pulse on time are most influencing parameters that are directly proportional to MRR and inversely proportional to TWR, SR. The rectangle tool geometry gave better results compared to other geometry
Path Optimization for Mobile Robot Based on the Sine Type Adaptive Genetic Algorithm
Authors: Zhao Jia Li , Hu Chi Bing , Feng Wu Yang , Yang Ning Du
Published: March 2012

The improved adaptive genetic algorithm has been presented to overcome the premature convergence problem of traditional genetic algorithm and obtain the genetic operator having adaptability at any time. Then, the location in the working space has been setted by the serial number method, and the mathematical model has been established for the picking operation of mobile robot. Finally, the sine type adaptive genetic algorithm has been adopted to improve the initial path and get the optimal solution. In addition, a simulation has been conducted by the Matlab Genetic Algorithms Box to show that this algorithm is more quickly and efficiently for the path optimization of mobile robot.
Processing Parameters Optimization and Experiment Research of Automatic Polishing Technology for Free Surface of Dies
Authors: Li Dong Ming , Jia Ying , Tian Xiao Jing , Ren Xian Ke , Yin Jun Wei
Published: March 2012

Abstract: A kind of automatic polishing equipment for free surface of dies is designed, which is fixed on the backbone of numerical control machine. Processing parameters optimization are gotten by the orthogonal analysis method based on experiment data and surface roughness is about 1.0μm, which provides good basis of practical research and application of accurate working for free surface of dies.
Research on Analytical Method of CNC Machine Tool Precision Recession
Authors: Fan Jin Wei , Wang Xiao Feng , Li Yun
Published: March 2012

The focus of this paper is to find a new method analyzing the reasons of CNC machine tool precision recession. The modeling of the movement error of CNC machine tool is one of the most important problem for kinematics designing and accuracy analysis. In this dissertation, this study analyzes the six movement error parameters of guide and the model of the guide which including foundation deformation, material’s natural ageing and way rub has been established. A detailed example is given for the modeling precision recession of 3-axis CNC machine tool.
Reverse Modeling of Auto Part Reconstruction Based on CATIA
Authors: Zhou Yu Qing
Published: March 2012

Abstract: In the light of the problem of low efficiency in reverse engineering model reconstruction, taking Auto part as object of study, analysis the key technology in this paper. One method is proposed to improve the design efficiency for Auto part model reconstruction. First of all, point cloud is acquired by camera style 3D scanner and processed by Geomagic software; then it is imported to CATIA software for Parameters reproduction and model reconstruction. Results show that this method can improve the efficiency of Auto part model reconstruction, and provide one workable way for CAD model reconstruction with complex surface.
Study on a New KIC Gradient Composites
Authors: Wei Feng Chun , Zhang Xiu Li , Song Qiang Wei
Published: March 2012

In this paper, a KIC gradient composite plate was designed and prepared by changing material prescriptions to make the KIC gradient change along the thickness direction. The expression of fracture toughness at any point within the gradient composites was derived, and the crack propagation behavior was examined by drop-weight impact test. The test results show that under impacting, the macro-crack propagates rapidly in the layer with lower KIC value because of the structure of this gradient composite material, but the high crack propagation resistance in the thickness direction of the plate observed.
Study on Measurement of Energy Consumption for Cranes and Designing of Energy Saving Device
Authors: Xiao Xin Yi , Lu Shi Qing
Published: March 2012

As port cranes becoming larger, the electricity and other energy they consumed increase significantly. The research on energy saving of port cranes is increasingly hot nowadays. This paper first discusses the latest research activities on the energy saving measures of cranes. Then, taking the quayside container crane as an example, the measuring method for its energy consumption is presented and analyzed. Finally, an energy saving device for port cranes is designed to convert the motor’s no useful working energy into electricity for lighting. The design, structures and working process of this device are described in detail.
The Application of the TCP/IP on the Robot System
Authors: Jiang Yun Fei
Published: March 2012

This paper puts forward a control model that is made up of the series robot, the parallel moving platform and the polishing tool system and so on. In order to realize the communication between the two robots in the robot system, a wireless LAN access point for establishing wireless LAN of two robots communication is first provided. In the end, the mutual communication can be accomplished by two robots and the robot position and status information can be transported with programming of the win socket. The satisfied polishing effect on the curved surfaces can be obtained and the demand of the polishing can be achieved.
The DNA Genetic Algorithm Applied for Solving Optimal Placement of Sensors
Authors: Liu Xin , Feng Zhong Ren , Wang Xiong Jian , Wang Bao Fu
Published: March 2012

In order to solve optimal placement of bridge sensors based on the modal information, a multi-objective integer programming expected value model is established and the number of modal is considered as a stochastic variable in this paper, and here Fisher and MAC matrix are combined as the objective functions . Since DNA Genetic algorithm has the merits of plentiful coding, and decoding, conveying complex knowledge flexibly, these merits and the technique of stochastic simulation are also combined, which for estimating stochastic integer programming expected value models problem. And finally the feasibility of the algorithm is showed by XuGe Bridge as an example.
Research on an Improved Cellular Automata Model
Authors: Wang Hong , Liu Yu Qiu , Zhou Li Hui
Published: March 2012

We introduce type-2 fuzzy reasoning to models of cellular automata, and combine type-2 fuzzy logic and classic cellular automata model to establish a new model of evolution reasoning, cellular automata model based on type-2 fuzzy logic. The key parts of cellular automata are transition functions and cell states. We fuzzify the transition functions of cellular automata into type-2 fuzzy rules, and cell states into type-2 fuzzy states too. Thus, we establish an improved cellular automata model based on type-2 fuzzy logic.
Determining the Soil Water Characteristic Curve in Term of Van Genuchten Parameters by the Particle Swarm Optimization
Authors: Yang Xu , You Xue Yi , Ji Min
Published: March 2012

The optimization effects of the particle swarm optimization (PSO) on the parameters of Van Genuchten (VG) equation for the soil water characteristic curve were investigated. The results indicated that the VG parameters determined by the PSO were very close to those of experiments with a very high accuracy. The PSO was proven to be used as an optimization method for estimating VG parameters for the soil water characteristic curve. The PSO had the higher parameter precision than the damped least squares method and the nonlinear simplex method. The particle swarm optimization was improved and its convergence accuracy was higher than that of constriction factor particle swarm optimization (CFPSO) and PSO of Filedsend.
Automatic Recognition of Aircraft Noise with PLP Method
Authors: Ding Jian Li , Yang Yong
Published: March 2012

This paper proposes a modified auditory feature extraction algorithm based on perceptual linear predictive analysis which is more suitable for automatic recognition of aircraft noise. In this algorithm, a different distribution of filter-bank is introduced in order to fit the physical characteristic of aircraft noise and the result shows that the modified method indeed performs better. The effect of Gammatone filter in improving the robustness of recognition algorithm is also demonstrated in the experiment.
Reduction Algorithms for Multi-Covering Information System
Authors: Zhang Shao Pu , Feng Tao
Published: March 2012

This paper discusses the reduction algorithms of a multi-covering decision system. Firstly, we give the belief structure in a covering system and give a rule of information fusion of multi-covering information. Then, we introduce special conditional entropy of a covering decision system with multi-coverings by the fused mass function and study the reduction of multi-covering information by means of limited conditional entropy and consistent multi-covering decision systems by means of conditional entropy. Two algorithms are designed to compute reductions of a multi-covering system and a consistent covering decision system, respectively.
The Lifetime Model of the One-Unit-System with Two Kinds of Wear-Out
Authors: Zhang Cheng Wei , Lin Wei Ran
Published: March 2012

A system at inception is endowed with a random amount of resource, the process of the lapse of system life can be viewed as that of the depletion of random resource caused by the wear-out effect. This thesis considers the wear-out process of the system as the sum of an additive compound nonhomogeneous poisson shock wear-out and a continuous routine wear-out in time t. With the introduction of the concept of random resource, a wear-out model is built. Moreover, the aging properties of the system lifetime are studied in this model.
Shakedown on Thermal Barrier Coating and Simply Analytic Model
Authors: Yuan Yuan , Liu Kai , Shi Kun
Published: March 2012

A simply analytic model is developed base on wrinkle geometry model. The three concentric circles are adopted to represent top coat, oxide coat and bond coat of thermal barrier coating, and then shakedown analysis is established based on the model. A numerical model has been given base on wrinkle geometry model in a thermal barrier coating system, and the model on static shakedown analysis is developed by finite element method. Shakedown limit of thermal barrier coating is calculated for various undulation shape and thermal grown oxide. The simply analytic results and numerical results are approximate for undulation shape is not very irregular. The simply analytic model is convenient for calculating shakedown limit of thermal barrier coating.
Displacement Amplification Analysis for Parallel Four-Bar Mechanism
Authors: Yang Xue Feng , Li Wei , Liu Yu Fei
Published: March 2012

The displacement amplification and hysteresis of parallel four-bar mechanism using piezo actuator were researched in this paper. The displacement amplification was analyzed by employing the material bending theory firstly. Theoretical and FEM analysis proved that the amplification ratio of parallel four-bar mechanism is only related to the position of driving point and the guiding arm displacement is directly proportional to the input with the certain structure. Then the Preisach model was employed to model the hysteresis of guiding arm and using the model to perform the research on the output displacement of the mechanism. Experiments proved that the analysis is correct and showed that this model can effectively improve the accurate of the guiding arm output displacement and can realize output arbitrary series displacement using the Preisach interpolation surface.
Study of Aerodynamic Interactions of Dual Flapping Airfoils in Tandem Configurations
Authors: Zhu Bao Li , Wu Hui Pen , Xiao Tian Hang
Published: March 2012

The unsteady viscous flow fields of dual flapping airfoils in tandem configurations are simulated by a Navier-Stokes Solver based on dynamic deformable hybrid meshes. Aerodynamic interactions of three motion models are studied including flapping fore airfoil with fixed aft airfoil, two airfoils flapping in phase and out-of-phase. The results indicate that the aft airfoil in the wake of the flapping fore airfoil has great influence on the aerodynamic performance. When the fore airfoil flaps with a fixed aft airfoil, the thrust generation and thrust propulsive efficiency were enhanced by 65% and 44% respectively, compared to that of single flapping airfoil. When the two airfoils stoke in phase, the thrust generation is twice over that of single flapping airfoil. However the out-of-phase stroking has relatively much lower thrust.
Projective Synchronization for Brushless DC Motor (BLDCM) with Fractional-Order
Authors: Huang Su Hai
Published: March 2012

Based on orthogonal neural network，a stability theorem[9] and back-stepping approach，a novel adaptive nonlinear observer is designed for a class of fractional-order chaotic system where the nonlinear portion of the structure cannt be evaluated. The projective synchronization of fractional-order BLDCM chaotic system can be achieved.
Research on Selection and Matching Optimization of Automobile Drive Train
Authors: Zhang Guang Hui
Published: March 2012

This paper studies the evaluation methods on model selection, matching scheme and matching program of automotive engine, transmission and final drive. Based on the given matching condition of the engine and transmission, the complete vehicle parameters, engine stand test data and drive line parameter, the program can quickly conduct selection and matching to the engine and drive line in the database and display the simulation results of the vehicle power, fuel economy and emissions corresponding to the each matching program, with which to do comprehensive evaluation to the corresponding matching program, provide a reference for users with drive line match and design and lay foundation for software system completion.
Dynamic Characteristics Analysis for Fluid-Solid Coupling of Vertical Lifting Pipe in Transporting Coarse Particles
Authors: Zhou Zhi Jin , Wang Zhao , Lu Hao , Xia Yi Min
Published: March 2012

Fluid-solid coupling dynamic characteristics analysis of vertical cantilever lifting pipe in transporting coarse solid particles was conducted by adopting ADINA. Firstly, finite element models of pipe and fluid were built, which was solved by using ADINA/FSI module. Secondly dynamic characteristics of pipe vibration for different run-time, constrain conditions, volume concentration and transporting velocities were studied. Thirdly the stress and displacement characteristics were discussed under above conditions. The results were shown that stress and displacement will increase with transporting concentration and velocity rising; the shorter run-up time is, the bigger stress and displacement will be; stress and displacement of lifting pipe supportive anchor in weak constrain were greater than that in fixed connect condition. Analysis results have certain directive significance in future structure design, check, reducing vibration study for lifting pipeline in the ocean mining.
Modeling and Simulation of Aligning Process for Alignment Mechanism of Large Aircraft Component
Authors: Ying Zheng , Ke Ying Lin
Published: March 2012

The dynamic performance of alignment mechanism of large aircraft component is directly associated with the structure and clearance of spherical joints. To accurately evaluate this influence, kinematic and dynamic models of spherical joints are developed. Firstly, a kinematic model of spherical joints is established. Secondly, a dynamic model of spherical joints is derived from the kinematic model and continuous contact force model. Finally, simulations of alignment mechanism of large aircraft component are carried out for typical moving trajectories. The influences of moving trajectory on the dynamic performance of mechanism are analysed. The simulation results are also applicable to similar mechanism design, moving trajectory planning and kinematic joint wear forecasting.
Research Status of Several Key Technologies for the Development of Electric Vehicles
Authors: Zhao Hong , Li Gou Feng , Wang Ning Hui , Zheng Shun Li , Yu Li Jun , Gao Yun
Published: March 2012

Nowadays while the environmental protection consciousness of the people are constantly strengthening, the development and application of energy efficient vehicles, especially electric vehicles, have attracted the attention of governments and car manufacturers. Several classification approaches for electric vehicles are introduced in this paper, and the electric vehicle-related industry development goals for the next ten years in China are briefly described. Then introduced is the research status of some key technologies in the development of electric vehicles, including the battery technology, motor technology, electronic control technology and electromagnetic compatibility technology.
Analysis of Loads at Crankshaft Bearing for Scroll Compressor
Authors: Li Chao , Yu Yang , Zhao Man
Published: March 2012

According to the tangential force of crank pin approximately for radial force four times, between the radial gas force Fr and tangential gas force Ft acting on the orbiting scroll, the radial force is invariableness with the spindle rotation angle, but tangential force Ft with the spindle rotation angle changes, and in the discharge angle θ* at maximum. As a result of our comprehensive analyses to loads at crankshaft bearing of the scroll compressor as well as installation angle of the counter weight and mass of the counterweight, it is concluded that the imbalance residual quantity of the crank pin tangential force effects on crankshaft bearing and radial force acting on the crank pin, which results from gas force of orbiting scroll, is balanced, and the vibration of the scroll compressor is decreased. This paper puts forward a set of formulas, which are derived based on analysis of the loads at crankshaft of scroll compressor. The formulas can be used to determine the parameters of installation angle of the counterweight and the force of loads at crankshaft for scroll compressor.
The Oxygen-Ion Diffusion and Phase Transition in the La2Mo2-xWxO9 Samples Measured by Internal Friction Method
Authors: Li Dan , Li Xiang Hu
Published: March 2012

The effects of tungsten doping on the oxygen-ion diffusion and the phase transition in La2Mo2–xWxO9 samples (x = 0.5, 0.75, 1.0, 1.2) were studied using internal friction method. The results show that two peaks were detected in the internal friction-temperature spectra in the La2Mo2-xWxO9 samples, the low-temperature relaxation peak is associated with oxygen ion diffusion, and the high-temperature peak is associated with a phase transition from the static disordered state to the dynamic disordered state of oxygen ion/vacancy distribution.
Effect of Polymerizable Surfactant Modified Clay on the Morpholorgy and Flexural Properties of Diallyl Phthalate/Clay Nanocomposites
Authors: Kong Zhen Xing , Li Gui Ying , Dai Zi Lin
Published: March 2012

The objective of this study is to examine the role of polymerizable and unpolymerizable pendant group of surfactant in clay dispersion in diallyl phthalate (DAP) matrix and evaluate the mechanical properties of resulting nanocomposites. Results of X-ray Diffraction (XRD) and high magnification Transmission Electron Microscopy (TEM) indicate an intercalated morphology for both types of nanocomposites, while low magnification TEM results show better dispersion of clay tactoids in the nanocomposite formulated with organclay containing polymerizable terminal pendant group. The mechanical properties of nanocomposites with organoclay loading of 1, 3, 5 and 7 wt%, respectively, were determined by performing flexural measurements. The testing results show that the nanocomposite formulated with organclay containing polymerizable terminal pendant group has better flexural properties than that formulated with organoclay containing unpolymerizable pendant group.
Effect of the Addition of α-Si3N4 on the Direct Nitridation of Silicon Powder at Atmospheric Pressure
Authors: Yang Fu Ming , Wang Li , Yin Shao Wu , Li Yan Hui , Liu Chuan Ping , Tong Li Ge
Published: March 2012

Effect of the addition of α-Si3N4 on the nitridation of silicon powder was studied at 1550 and atmospheric pressure. Silicon powder of 2.2μm in size and 99.99% in purity was adopted as experimental materials, α-Si3N4 powder of 2.2μm in size and 99% in purity was used as diluent, and nitrogen of 99.9993% in purity was used as reaction gas. The morphologies and phase compositions of the products were analyzed by SEM and XRD respectively. The results show that the conversion of silicon is improved considerably by increasing the adding proportion of α-Si3N4 diluent. When the adding proportion of α-Si3N4 increases from 10% to 50%, the conversion of silicon powder increases from 38% to 92.55%. The content of β-Si3N4 in product decreases, after an initial increase, with the adding proportion of α-Si3N4 increases, and it reaches the peak point when the adding proportion of α-Si3N4 was 30%. The sinterability of silicon nitride decreases as the content of β phase increases, so the adding proportion of α-Si3N4 should be kept away from 30%.
The Factors that Affect the Function of Dye-Sensitized Solar Cell
Authors: Liu Hui Wen , Feng Xiao Wei , Hu Fei , Zhu Hua , Xing Peng
Published: March 2012

Recently, dye-sensitized solar cell has become one of the hottest studies of solar cell due to it's higher efficiency on photoelectric transformation and lower cost. This article has introduced the preparation methods of dye-sensitized solar cell and other factors that can influence it's function, which has described the way of improving the performance of film electrode and increasing the efficiency on photoelectric transformation.
A Service Life Prediction for Waste Disposal Concrete under Carbonation
Authors: Kim Ki Beom , Jung Hae Ryong , Kwon Ki Jung , Lee Jang Hwa , Kim Do Gyeum
Published: March 2012

The scope of this study was to investigate the carbonation of waste disposal facility concrete. The effects of the silo concrete mixture on the physical properties of concrete and the alteration of the microstructure of the cement paste due to exposure to carbon dioxide were included in this investigation.
The Precipitation and Dissolution of Alloy Iron Carbides in Vacuum Carburization Processes for Automotive and Aircraft Applications - Part I
Authors: Kula Piotr , Wołowiec Emilia , Pietrasik Robert , Dybowski Konrad , Klimek Leszek
Published: March 2012

The article is dedicated to the experiments and tests on the phenomena of precipitation and dissolution of alloy iron carbides in vacuum carburization processes. This researches was done in order to evaluate to the possibility of using artificial neural networks to predict the speed of the processes examined (it is described in the part II). In the section below, we are presenting the precipitation phenomena taking place in vacuum carburization processes and the experiments that were conducted.
The Precipitation and Dissolution of Alloy Iron Carbides in Vacuum Carburization Processes for Automotive and Aircraft Applications - Part II
Authors: Kula Piotr , Wołowiec Emilia , Pietrasik Robert , Dybowski Konrad , Klimek Leszek
Published: March 2012

The article is dedicated to the experiments and tests on the phenomena of precipitation and dissolution of alloy iron carbides in vacuum carburization processes. Special attention has been paid to the possibility of using artificial neural networks to predict the speed of the processes examined. In the section below, we are presenting the precipitation phenomena taking place in vacuum carburization processes and the experiments that were conducted. Moreover, a qualitative and metallographic analysis of carbide phenomena was described together with the method of numerical modelling and predicting the processes with the use of artificial neural networks.
Continuous Sheet Metal Forming - A Linearly Incremental Forming Method for Manufacturing 3D Surface Parts
Authors: Cai Zhong Yi , Hu Zhi Qing , Lan Ying Wu , Li Ming Zhe
Published: March 2012

In order to manufacture a three dimensional sheet metal part effectively, a continuous sheet metal forming process (CSMF) based on flexible roll bending has been proposed and developed. This paper mainly focuses on the fundamental aspects of the process, the principle of CSMF is introduced and the method to estimate the downward displacement of upper roll based on the desired curvature of the deformed sheet metal is presented. The variation of the upper rolls downward displacement with the desired bend radius is shown in graphically. The smoothness of the CSMF parts was measured and analyzed. In the results, it is shown that a three-dimensional sheet metal part can be formed without defects and the formed surfaces are in good agreement with the target shapes.
Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors under UV Illumination
Authors: Chang S.P.
Published: March 2012

A zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 h in air to create a gas sensor. The responses of the gas sensor to ethanol under UV light illumination were investigated. We found that the ZnO nanoparticle film annealed at 800°C had the highest sensitivity. This can be attributed to the fact that the defects of ZnO nanoparticle film annealed at 800°C are considerably more than those for the film annealed at other temperatures. This study demonstrates that ZnO nanoparticles have potential applications as room-temperature ethanol sensors.
Study on the Phase Transformation Simulation of Hot-Stamping
Authors: Gu Tian , Lei Cheng Xi , Xing Zhong Wen
Published: March 2012

The temperature fields in hot-stamping process for BR1500HS steel sheet was simulated under the ABAQUS environment. Python scripting language was used for post-processing module of ABAQUS for secondary development, to obtain the volume fraction of martensite based on the formulas proposed by Koistinen and Marburger. The comparison results between simulation and metallograph show that the simulation can predict the volume fraction of martensitic effectively and thus can provide the guidance for the optimizing process parameters.
Surface Effects on the Buckling of Piezoelectric Nanobeams
Authors: Wang Kai Fa , Wang Bao Lin
Published: March 2012

In this paper, we analyze the influence of surface effects including residual surface stress, surface piezoelectric and surface elasticity on the buckling behavior of piezoelectric nanobeams by using the Timoshenko beam theory and surface piezoelectricity model. The critical electric potential for buckling of piezoelectric nanobeams with different boundary condition is obtained analytically. From the results, it is found that the surface piezoelectric reduces the critical electric potential. However, a positive residual surface stress increases the critical electric potential. In addition, the shear deformation reduces the critical electric potential, and the influence of shear deformation become more significant for a stubby piezoelectric nanobeam.
Microstructure, Hardness and Electrical Conductivity of Silver-Metal Oxides Electrical Contact Materials
Authors: Wathanyu Kessaraporn , Rojananan Siriporn
Published: March 2012

The aim of this paper was to study the microstructure, hardness and electrical conductivity of silver-metal oxides electrical contact materials. The Ag-SnO2, Ag-ZnO and Ag-CuO were prepared by powder metallurgy process. The density, microstructure, hardness and electrical conductivity were investigated. The results showed that the density of silver-metal oxides were 91-96% of theoretical density. The microstructures exhibited that the metal oxides were uniform dispersion in the silver matrix. The hardness of Ag-(5, 10)SnO2 and Ag-(5, 10)ZnO samples were about 100 HV and the hardness of Ag-(5, 10)CuO samples were about 88 HV. The Ag-5CuO samples had the highest electrical conductivity at the value of 91.27 %IACS.
Fabrication of Nanofibers by Low-Voltage Near-Field Electrospinning
Authors: Zheng Jie , Sun Bin , Long Yun Ze , Zhang Hong Di , Zhang Zhi Ming , Zhang Zhi Hua , Han Wei Hua , Shao Feng , Huang Jia Yin
Published: March 2012

In this paper, non-woven micro-/nanofibers and wavelike micro-ribbons were produced by a low-voltage near-field electrospinning with working voltage less than 2.8 kV and spinning distance less than 8 mm. A series of experiments were carried out to explore the influence of processing variables on the formation of near-field electrospun nanofibers (polyvinyl pyrrolidone (PVP) as an example), including concentration, humidity and spinning distance. The formation mechanism of helical fibers and wavelike micro-ribbons was also discussed, which can be ascribed to electrical driven bending instability and/or mechanical jet buckling when hitting the collector surface. The results indicate that the morphology of the electrospun fibers can be controlled by experimental variables. And the low-voltage near-field electrospinning is a promising technique which may be used in precision deposition of nanofibers for nanodevices, direct-write nanofabrication, etc.
Synthesis and Characteristic of NiFe/NiFe2O4 Core-Shell Magnetic Nanocomposite Particles
Authors: Hu Jun , Chen Ai Min
Published: March 2012

NiFe/NiFe2O4 core-shell bimagnetic nanocomposite particles were successfully synthesized by colloidal chemical method combined with H2 reduction. The whole structural evolution process has been well studied through analysis of X-ray diffraction patterns and Infrared spectra. It has been found that FeNi alloy concentrated in the ferrite phase. The core/shell structure, a FeNi alloy core surrounded by NiFe2O4 spinel oxide shell were verified by X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The influence of post H2 heat treatment temperature on nanoparticles was investigated. The core-shell NiFe/ NiFe2O4 nanoparticles was about 100 nm after reduced at 727 K, The powders exhibited paramagnetic properties and the magnetization was 29.9 emu·g-1.
Preparation and Crystallization of Nd2Fe14B/α-Fe Permanent Magnetic Nanomaterial by Mechanical Milling
Authors: Jin Yong Ping , Hu Ming , Gao Jin
Published: March 2012

Nanocomposite Nd2Fe14B/α-Fe magnetic material had been prepared by mechanical milling Nd8Fe86B6 as-cast alloy in Argon and subsequent crystallization. Effect of mechanical milling and crystallization technique on its structure had been investigated by means of X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and Differential Scanning Caborimetry (DSC), etc. The crystallization behavior of amorphous Nd8Fe86B6 powders had also been studied. The results showed that Nd2Fe14B grain refined quickly and the grain size of α-Fe decreased while extending milling time. After milling for 25h, grain size of α-Fe reached a constant (about 7nm). Higher temperature of complete crystallization as well as finer and more homogeneous grains resulted from longer milling time. During the process of crystallization, the total amorphous phase crystallized into four phases firstly, i.e., Nd4.4Fe77.8B17.8, Nd1.1Fe4B4, Nd2Fe14B and α-Fe. At higher temperature, final mixture was consisted of Nd2Fe14B, α-Fe and a few undecomposed Nd1.1Fe4B4 phase.
Influence of Mo Content of Fe/Mo/Al2O3 on Flame Synthesis of Carbon Nanotubes
Authors: Yuan Yuan , Sun Bao Min , Wang Xiao Tian , Wang Yang , Guo Yong Hong
Published: March 2012

Catalysts play a critical role in the synthesis of carbon nanotubes. In this paper, we design a series of experiments to explore the impact of contents of Mo on the products. Analysis show, when the molar ratio of Fe: Mo: Al is 1: 0.2: 16, the carbon nanotubes show the best yields and quality.
Kinetics of 2-Chloro-6-Nitrotoluene Hydrogenation on Palladium/Carbon Catalyst without Inhibitors
Authors: Wen Feng , Zhu Yi Feng , Li Xiao Nian
Published: March 2012

Pd-only catalyst supported on activated carbon has been prepared by chemical impregnation and used to catalyze the hydrogenation of 2-chloro-6-nitrotoluene (2-CNT) to 3-chloro-2-methylaniline in solvent-free condition. The effects of reaction temperature，H2 pressure on the hydrogenation have been investigated. The reaction showed very high selectivity with the dehalogenation side product with a yield of less than 1.2 %. The most favorable conditions could be temperature= 353 K, stirring speed= 1200 rpm, H2 pressure= 1 MPa. The catalytic hydrogenation reaction was found to have a zero order with hydrogen and 1 order with 2-CNT. The apparent activation energy of the hydrogenation was 60.58 kJ/mol.
Preparation of (321) Oriented Silicon Clathrate Film by a Sol-Gel Method
Authors: Gong Min , Zhu Xing Wen , Xu Tie Zhu , Li Li Zhe , Jiang Wen Zhong , Zhou Xiao
Published: March 2012

In this paper, Na+-doped silicon clathrate thin films were prepared on Si substrate by sol-gel method using zinc acetate and sodium carbonate as starting materials and the effects of the growth conditions on the structural of the films have been investigated by XRD, HRTEM, SAED analysis. The XRD results showed that there only existed a narrow and sharp peak around 2θ=32.94º which was assigned as the diffraction of Na8Si46(321). However, the peak at 2θ=32.94º disappeared when it was heated to above 640°C due to the decomposition of the silicon clathrates. Minute Zn2+ions in the gel was proved to promote the formation of Na-doped silicon clathrates. The HRTEM photos revealed that the thickness of the films was only about 15nm, and there existed no obvious interfaces between the film and the silicon substrate.
Effect of Structure of Polycarboxylate Superplasticizer on Hydration of Cement in Early Period
Authors: Duan Jian Ping , Lv Sheng Hua
Published: March 2012

Effect of polycarboxylate superplasticizer (PCs) with different bond between side chain and truck chain on hydration of cement in early period was studied. The performance of PCs in concrete was investigated by setting time, TGA and SEM. PC-based superplasticizer with ester bonding between side chain and truck chain. Although they had the proximate structure parameters in density of side chain and absorption group (carboxyl groups), the setting time of cement paste was significantly different when different PCs were employed in the preparation of cement. Decomposing of this bond in alkali environment may lead to a shorter setting time. On the other hand, same difference in hydration production was observed in early period hydration of cement paste when two different PCs was incorporated, which indicated that the different bond structure in PCs affected the hydration of cement in a different manner. The result of SEM indicated that the morphological phase of hydrated product was different when PC was applied, this may be related with the different result in the TG and TGA
Single-Phase Sine Inverter Power Supply Based on PIC18F2431
Authors: Li Hong , Yu Jun
Published: March 2012

According to the principle of equivalent surface area and Nyquist sampling theorem, this paper introduces the method which takes PIC18F2431 SCM as the control center in details, and it forms Single-phase sine inverter power supply by adopting the principle of equivalent surface area directly. This method that can be widely used in controlling Single-phase AC motor speed is simple and cost-effective.
Simplified Simulation and Compute of the Horizontal Displacement of Diaphragm Wall
Authors: Yan Xiao Xin , Chu Yue Hua , Li Zong Ming , Cao Bao Ping
Published: March 2012

When using ANSYS to simulate and compute a diaphragm wall, because of the complexity of soil properties, soil beneath bottom foundation pit will have to be simulated by several different soil layers. This makes it much more complicated of simulation and compute. In order to simplify the simulation method, in this article, we get a new theory of zero-displacement insertion and fixation under a certain depth. In this way we can control displacement under a certain depth to be zero by changing parameters of analogue cells and simplify simulation and compute.
The Mechanical Properties of Natural Fiber
Authors: Ma Yun Hai , Lin Fu Dong , Wang Bao Gang , Tong Jin , Jia Hong Lei
Published: March 2012

The jute fiber, bamboo fiber and wool fiber reinforced friction material were carried out Surface modification by 2wt.%NaOH solution. The tensile strength, elastic modulus, density and hardness of the composites were tested. The result showed that the Tensile Properties of modified jute fiber and bamboo fiber were improved, while the wool is the opposite. The density and hardness of composites has been reduced with fiber content increase. The morphology of the friction material surfaces was examined by SEM.
A Method of Seabed Soil Image Reconstruction Based on Compressed Sensing
Authors: Xu Zhi Jing , Jiang Li , Dai Huan Lei
Published: March 2012

Compressed Sensing(CS) can project a high dimensional signal to a low dimensional signal by a random measurement matrix . As the projection calculation is time-consuming in the process of reconstruction, the reconstruction speed is greatly affected.In order to improve the reconstruction speed , some improvement in the selection of the measurement matrix and the design of the reconstruction algorithm is made. The wavelet transform is used to sparse decompose the image, and the very sparse random projection matrix is used as the measurement matrix, after the image block processing we use the OMP algorithm to reconstruct the image. The experimental result shows that this method could reduce the algorithm time and improved the reconstruction speed greatly.
Research on Maladjustment-Free Control Algorithm of Bi-Weight Balancer
Authors: Chen Li Fang , Wu Hai Qi , Gao Jin Ji
Published: March 2012

By analysis of the reasons such as maladjustment, vibration and long balancing time which from existing motor-driven bi-weight balancer; we propose solutions and apply them into a new design of magnetic-driven bi-weight balancer. By means of analyzing the bi-weight balancer system, we have raised the rules for optimum movement of the balancing weight and its judgment principles. We have summarized the maladjustment-free control algorithm of bi-weight balancer, carried out simulation experiment verification. The results show that the mobile strategy can effectively improve the quality of auto-balancing and achieve the purpose of no maladjustment, no oscillation and short balancing time.
Mechanical Properties of the Regenerated Rubber Prepared by Waste Tire Powders and Fillers
Authors: Zhang Zhi Lei , Zhang Yi He , Meng Xiang Hai
Published: March 2012

Waste tire powder (WTP) was reclaimed mechanically in presence of a new composite additive which consists of reinforcing materials (RM) and toughening materials (TM), and the effects of technical parameters and additives were investigated. According to the orthogonal experiments and the range analysis, the final ranking of the significance of factors in tensile properties was determined to be as follows: TM content > curing temperature > sulfur content > TBBS content > RM content (for tensile strength) and sulfur content > curing temperature > TBBS content > TM content > RM content (for elongation at break). The optimal conditions for tensile strength and elongation at break were determined respectively. Tensile strength and elongation at break tended to decrease after an initial ascent with the RM content increased. An apparent ascent of elongation at break was observed as TM content increases. Tensile strength increased first, and then decreased.
Investigation of Compressive and Damage Mechanisms in Fully Lamellar TiAl-Based Alloy
Authors: Tang Bin , Chen Chuan Jing , Xue Zi Gong , Wu Chun Jing , Li Shuang Shou
Published: March 2012

The compressive Properties and the effect of anti-damage were studied by means of compression and pre-compression damage tests. The study indicated that：The fracture mechanisms of compression tests were quasi-cleavage fracture attributed to the normal stress and shear stress. Fracture strength, the maximum strain and the fracture energy were reduced in varying degrees, and the damage was intensified while increasing preload value. The mechanical property of the TiAl alloy degrades because of the present of the cracks, and large amount of micro-cracks appear on the surface firstly.
Research on the Fatigue Fracture Surface of X60 Pipeline Steel after per-Tension Deformation
Authors: Jiang Yu Rong , Chen Mei Bao
Published: March 2012

It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation of X60 pipeline steel was employed to experimentally simulate the influence of dents and the fatigue fracture surfaces of X60 pipeline steel after per-tension deformation under cyclic loading were investigated. The results indicate that the static state tensile mechanics is the dominant factor in the fracture mechanisms at high stress ratio. With the decrease of the stress ratio R, the fractograph presents evident fatigue facture characteristics. The amount and intensity of MnS inclusion evidently increase with the loading frequency decrease and the typical cleavage fracture characteristics have been found.
Microstructure and Damping Property of the Discontinuous NiTi SMA Thin Films/PZT Substrate Composite
Authors: Dong Zhan Ji , Liu Qing Suo , Lv Lian Rong , Gao Xiao Yun , Kong De Qun
Published: March 2012

Discontinuous NiTi SMA thin films were deposited on PZT substrate by magnetron sputtering method with a specially designed pore plate. The microstructure and damping property of the prepared composite were studied with X-Ray diffraction, scanning electric microscopy and dynamic elastic modulus apparatus. It was found that NiTi SMA thin films with physical dimension of width of less-than or equal to 2mm and distance between the adjacent thin films of 1mm are of best equiaxed crystal microstructure after crystallization at 600°C. The damping effect of the composite is still caused by PZT and the damping value is generally lower than that of pure PZT, about 9.9%.
Study on Relationship between Structure and Properties of Polycarboxylate Superplasticizer
Authors: Lv Sheng Hua , Li Di , Cao Qiang
Published: March 2012

A polycarboxylate superplasticizer (PCs) was synthesized by copolymerization of allyl polyoxyethylene ethers (APE), acrylic acid (AA), sodium methylallyl Sulfonate (SMAS) and ethyl acrylate (EA). The effect of functional groups and branch chain on PCs properties was investigated by the test of fluidity of cement paste, retardation performance and Zeta potential of cement particles. The results showed that carboxylic groups and ethyl ester groups can improve water reducing ratio and fluidity of cement paste, and the sulfonic groups has an important contributiion to retardation performance of PCs.
Models for Autogenous Shrinkage in Low Water-Binder Ratios Concrete
Authors: Zhu Qiao , Jiang Lin Hua , Xu Jin Xia
Published: March 2012

Non-structural cracking of concrete is a serious problem and the underlying phenomena, namely, shrinkage and creep, need to be better understood. Much research has been devoted to this complex problem. However, despite major successes, the phenomenon of autogenous shrinkage is still far from being fully understood. The paper discusses the main aspects of concrete shrinkage, with a focus on autogenous shrinkage, which are especially important in low water/binder ratio concrete. These aspects include the theories of physical mechanism, prediction models and future research trends. Shrinkage of concrete due to moisture changes, which result in surface and capillary tension, was reviewed. The mechanisms often cannot be directly linked to the macroscopically observed dilatation/contraction. An overview of recent model developments is also presented.
Deformation Research of T10 Steel at Low Stress Repeated Impact
Authors: Wu Jiong Jie , Fu Ge Yan
Published: March 2012

The research use an impact test enginery, choose T10 steel samples, and do a low stress repeated impact collisions experiment. By comparing two kinds of different heat treatment of T10 steel, analyze and research its macro plastic deformation phenomena and plastic accumulation law in low stress repeated collision impact load, and observe its hardness change by hardness microscopicand and its metallographic structure by metallographic microscope to discuss its deformation causes.
Numerical Analysis on Heat Transfer Coefficient of Large Die Steel Quenching
Authors: Bian Xin Xiao , Zhang Chao , Qian Lin Zhu
Published: March 2012

Heat transfer coefficient is one of the most important boundary conditions for quenching process simulation. It depends on many factors, such as material, size, surface conditions of a part, and so on. It is, therefore, difficult to evaluate the heat transfer coefficient accurately. T In the environment for large modules P20 and the actual heat transfer conditions, the off-line air-cooling heat transfer coefficient of C are simulated by using empirical equations.