bluuebunny/crossref_metadata_2025 huggingface dataset:
Periodicity and Trend Analysis of Precipitation in Multi-Time Scale in Plain Regions of Handan, China
Authors: Luan Qing Hua , Yuan Jian , Ma Zhong Zhuang , Hao Xiao Bo , Wu Tai Bing
Published: September 2010

The periodicity and the trend which are the important properties of water resources become more and more variable and complex because of the influence of topography, vegetation and the human activities. Wavelet Analysis which has Multi-resolution Analysis function can provide more detail information of the nonlinear and complex system. The periodicity and the trend of precipitation in different plain regions of Handan are illuminated with Morlet Wavelet Transform in Multi-time scales in this study. It is illustrated that the same periods (5years and 9years) exist in the precipitation in different plain regions of Handan and there are the similar variety and the similar trend in the scale of 5years or 9years in different areas. This study would provide technical support for the integrated management and utilization of water resources of the local region.
Monte Carlo Simulation for the Angle-Dependent Light Transmittance of Thermotropic Material
Authors: Yao Jian , Xu Jin
Published: September 2010

In this paper we propose a Monte-Carlo method for the simulation of the angle-dependent light transmittance of thermotropic material. The results show that the scattering light increased as temperature rose, and most of light transmitted went through the sample of thermotropic material at the angles between 10~40 deg. The results also indicate that the light transmittance measurement of thermotropic material by spectrophotometer without an integrating sphere is not accurate. As a conclusion, Monte Carlo simulation is an effective method for the determination of angle-dependent light transmittance of thermotropic material, and results of these simulations can be used to calculate the shading coefficient of window for building energy efficiency.
Indoor Thermal Environment Simulation by Using MATLAB and Simulink
Authors: Yao Jian , Xu Jin
Published: September 2010

To compare the indoor thermal environment under different building envelope constructions, a Matlab-based tool was presented for building envelope performance simulation. An application study of two cases illustrates energy efficient buildings can provide more suitable indoor environment than non-energy efficient buildings in cold winter and hot summer. In conclusion, this paper provides a new and fast way for the prediction of indoor thermal environment.
Solitary Waves and Chaotic Behavior in Large-Deflection Beam
Authors: Zhou Yi Qing , Liu Zhi Fang , Zhang Shan Yuan
Published: September 2010

The motion equation of nonlinear flexural wave in large-deflection beam is derived from Hamilton's variational principle using the coupling of flexural deformation and midplane stretching as key source of nonlinearity and taking into account transverse, axial and rotary inertia effects. The system has homoclinic or heteroclinic orbit under certain conditions, the exact periodic solutions of nonlinear wave equation are obtained by means of Jacobi elliptic function expansion. The solitary wave solution and shock wave solution is given when the modulus of Jacobi elliptic function in the degenerate case. It is easily thought that the introduction of damping and external load can result in break of homoclinic (or heteroclinic) orbit and appearance of transverse homoclinic point. The threshold condition of the existence of transverse homoclinic point is given by help of Melnikov function. It shows that the system has chaos property under Smale horseshoe meaning.
Research on the BPNN in the Prediction of PMV
Authors: Yao Jian , Xu Jin
Published: September 2010

In view of the problem that it is difficult to calculate the Fanger’s PMV equation due to its complicated iterative process, a backpropagation neural network (BPNN) model was built to predict PMV. Air temperature, relative humidity, mean radiant temperature, air velocity, metabolic rate and clothing index were used as the input of neural network and PMV output as the output of the neural network. The results show that this prediction approach is very effective and has higher accuracy absolute error below 5%. As a conclusion, this study has a real signiﬁcance, because it gives a new method with reliability and accuracy in the prediction of PMV.
Methods for Crack Prevention of Large Volume Concrete Foundation of High-Rise Building
Authors: Guo Jin Jun , Wang Wei
Published: September 2010

Crack prevention of high-rise building foundation is an interesting and difficult issue to engineers. Reasons for the crack are analyzed first. Then, based on project cases, crack control methods of large volume concrete foundation are studied in terms of active part and passive part. Active part includes optimizing design of concrete, optimizing foundation design and improving confining condition. Passive part includes reducing temperature difference and increasing the fracture strength of concrete. Finally, optimum foundation design is emphasized for crack control of large volume concrete foundation.
Mechanical Behaviours of Open-Cell and Closed-Cell Aluminium Foams against Spherical-Nosed Projectile Penetration
Authors: Yan Xiao Peng , Zhang Nian Mei , Liang Wei Min , Zhao Yong Gang , Yang Gui Tong
Published: September 2010

In this paper, the mechanical behaviours of open-cell and closed-cell aluminium foams against spherical-nosed projectile penetration are studied theoretically. An analytical model based on dynamic cavity expansion theory and previous experiment data is presented. The analytical equations are derived for the penetration resistance and the final penetration depth during the whole penetrating process. The effects of the mass density of target material, the geometry and initial velocity of the projectiles on the final penetration depth are investigated in detail. It is shown that the final penetration depth mostly lie on the density of aluminium foams and the kinetic energy of projectile. When the density of target is smaller, the final penetration depth of projectile in the closed-cell aluminium foams target is obviously smaller than that in the open-cell aluminium foams target. Meanwhile, with the increase of density of target and the decrease of initial impact velocity, the difference of the capacity of absorbing energy between open-cell and closed-cell aluminium foams targets becomes gradually narrow.
Nodal Evolutionary Computation Enhanced Level Set Algorithm for Structural Topology Optimization
Authors: Jia Hai Peng , Jiang Chun Dong , Liu Bo , Cao Dong Xing , Jiang Chun Bo
Published: September 2010

This paper proposes an improved computational algorithm for structure topology optimization. It integrates the merits of Evolutionary Structure Optimization and Level Set Method (LSM) for structure topology optimization. Traditional LSM algorithm has some drawbacks, for instance, its optimal topology configuration is largely dependent on the structural topology initialization. Additionally, new holes cannot be evolved within the updated topology during the optimization iteration. The method proposed in this paper combines the merits of ESO techniques with the LSM scheme, allowing new holes to be automatically inserted in regions with low deformation energy at prescribed iterations of the optimization. The nodal neighboring region is a good selection. For complex structures in which holes cannot be properly inserted in advance, the proposed method considerably improves the ability of LSM to search the optimal topology. In addition to achieving more accurate results, the proposed method also yields higher efficiency during optimization. Benchmark problems are presented to show the effectiveness and robustness of the new proposed algorithm.
Research on Coupled Water Hammer in Hydraulic Pipe System
Authors: Liao Jin Jun , Li Bao Ren
Published: September 2010

A one-dimensional mathematic model is presented which describes pressure fluctuations behavior of liquid-filled pipes. The model is based on conventional two-equations water hammer theory. Here is multi-water-hammer occurring simultaneously and coupling together. The differences are obvious when taking into account coupled water hammer and just single water hammer in Fluid pipe system by comparing the numerical simulation. The pressure characteristics located where water hammer takes place is investigated by numerical simulation and experiment. Then the factors of influencing on the coupled water-hammer pressure and frequency are considered, the result shows that system parameters effecting on it are critical and should be detailedly analyzed.
The Resistance-Heated Furnace Temperature Control Based on CMAC-Fuzzy Immune PID Control
Authors: Wen Ding Du
Published: September 2010

The control demand can not be satified by general PID algorithm because of time-change, nonlinear, uncertainty of controlled parameters in control process of the resistance-heated furnace. Based on regulative fuction of bilogic immune feedback response and characteristic of overhang nonlinear fuction with fuzzy discursion, and combining the advantages of CMAC(Cerebellar Model Articulation Controller), the CMAC-Fuzzy Immune-PID control strategy is applied to temperature control system of the resistance-heated furnace. Simulation study results show that control systems based on this method can attain high quality, is capable of adapting itself to variations of the control object’s parameters, and is featured by strong robustness and self-adaptability.
Virtual Five-Axis Milling of Free-Form Surface-Part II: Feed Optimization
Authors: Zhang Li Qiang , Yan Ye Cui
Published: September 2010

This paper presents process optimization for the five-axis milling based on the mechanics model explained in Part I. The process is optimized by varying the feed as the tool-workpiece engagements. The linear and angular feedrates are optimized by sequential quadratic programming. Sharp feedrate changes may result in undesired feed-marks on the finished surface. The adopted step is to update the the original CL file with optimized and filtered feedrate commands. The five-axis milling process is simulated in a virtual enviroment, and the resulting feedrate outputs are stored at each position along the tool path. The new feedrate profiles are shown to considerably reduce the machining time while avoiding process faults.
Time Domain Identification of Distributed Dynamic Load of Rotating Timoshenko Beam Based on Orthogonal Polynomial
Authors: Jun Deng , Zhang Fang , Chen Guo Ping
Published: September 2010

Based on the theory of two-dimensional (2-D) orthogonal polynomials, the function of dynamic load is fit by using the primary functions sequence. The identification of the distributed dynamic load can be transformed into the solution of the fitting coefficients. For the finite element model of the rotating Timoshenko beam, the unknown distributed force is identified by the load identification theory of the continuous beam in time domain. Numerical simulation shows that the method is precise as long as enough data of feedback points are collected; and it is simple and effective for engineering applications.
An Improved Model for Predicting Fatigue Crack Initiation Life of GH4169
Authors: Lei Dong , Li Ge , Shi Bin Kai , Zhao Jian Hua
Published: September 2010

An improved model has been developed to predict fatigue crack initiation life using the criterion of minimizing the Gibbs free energy change considering plastic energy. The prediction process was described in this paper and used to predict the fatigue crack initiation life of notched GH4169 superalloy rolled bar at room temperature and 450°C. The results are acceptable for fatigue crack initiation life prediction in engineering experience and show that the improved model for predicting fatigue crack initiation life as an extension of the concept of minimizing the Gibbs free energy change considering plastic energy is adoptable to some superplastic materials such as GH4169.
The Modeling Study on Kinematic Interface Joints Based on Accordant Displacement Method
Authors: Chen Xue Qian , Du Qiang , Chen Xiao Juan
Published: September 2010

The kinematic interface joints are widely used in reflector systems of the high-power solid-state laser facilities. In order to get better finite element(FE) analysis results of reflector systems, it is important to model the joints exactly. The accordant displacement method is used for modeling the joints according to the contact form of joints. The FE model of the reflector system is built subjected to the assuming, the modal analysis and the ambient vibration calculations are carried out. The computing results of inherent frequencies, measure points’ root mean square(RMS) displacements and the transfer characteristics of four kinematic interface positions are accordant with that of the test results. The compared results show that the method modeling the kinematic interface joints is feasible in the paper.
3D X-Ray Based BGA Solder Joints Inspection Algorithm
Authors: Zhang Rui Qiu , Zhang Xian Min , Chen Zhong
Published: September 2010

In order to improve the precision of BGA solder joints inspection, the cross-section images of BGA solder joints are analyzed based on the 3D X-ray technology. The BGA solder joints or the BGA ball and background is segmented. The features of BGA solder joints defects and decision rules are extracted. And then inspection algorithms in vertical and horizontal cross section are presented. The defects of short circuit, shift, lacking solder, void, warpage and broken circuit can be inspected by the proposed algorithm.
High-Speed Video of Micro-Detonation Arc Machining Process for Engineering Ceramics
Authors: Tian Xin Li , Zhang Bao Guo , Yang Jun Fei , Guo Fang
Published: September 2010

Micro-detonation arc machining (MDAM) is a newly proposed special machining technology for engineering ceramics. To study its working principle is of important significance. By means of high speed video and current signal acquisition system, the shape of micro-detonation arc is observed and the formation course of micro-detonation arc is analyzed. The generation process of ablation pits for Si3N4 and Al2O3 is observed by high speed video. Experimental results show that the generating process of micro-detonation arc can be divided into two phases: spark discharge and stable arc. The diameter of micro-detonation arc increases as working current growing. Si3N4 ceramics decompose and Al2O3 ceramics melts when it machined with MDAM. The materials are removed by synergistic effect of high temperature and intensive impact pressure of micro-detonation arc.
Fixture Layout and Clamping Force Optimization for Large-Scale Workpiece Using Augmented Lagrangian Method
Authors: Zhang Xiao Ping , Yang Wen Yu , Li Miao
Published: September 2010

The Fixture layout and clamping force are well known as important factors that influences the localization accuracy of the workpiece. Considering the unique characteristics of the Large-Scale workpiece in practice, we, in this paper, propose a unified method of optimizing an existing fixture configuration under heavy-duty condition based on Algmented Lagriangian Method (ALM). We fir- stly derived the models of localization error and static force equilibrium which describe the kinematic condition and quasi-static process of the fixture-workpiece system. Then, we introduce Hertz contact theory to better describe the nonlinear relationship of the local deformation and the contact force. Further, we define the minimum norm of the position error of critical points as the objective function and formulate a multi-constrained problem of solving the optimized fixture configuration. By using the ALM, the nonlinear constrained programming is transformed into an unconstrained one through which we obtain the optimal solution. Finally, a numerical example is presented and compared with the results of FEA simulation.
The Initial-Boundary Value Problem of a Nonlinear Thermoelastic Beam Equations
Authors: Zhang Jian Wen , Wang Dan Xia
Published: September 2010

Recently, with the development of mathematics itself and promotion of physics and other mechanics, the study of partial differential equation (equations) has become an important study subject. In this paper, we make research the initial-boundary value problem for a class of the thermoelastic beam equations. Namely, for the following coupled equations
Numerical Simulation of Solar Array with Shape Memory Alloy in Active Vibration Control
Authors: Zhang Yong Liang , Zhao Shou Gen , Long Lun , Li Kang
Published: September 2010

The objective of this study is to develop a general design scheme for shape memory alloys (SMA) intelligent structure. The scheme involves dynamic modeling and closed-loop simulation in a finite element environment. First, the structure of multi-body finite element model simulating the real solar array is established. SMA wire is appended on the model. The physical value of the strain, displacement, velocity and acceleration at the sensors locations separately is acted as the feedback signal. The value is multiplied by the control gain to calculate the voltage inputted to SMA wire. The finite element model is then modified to accept control laws and perform closed-loop simulations. Finally numerical examples have demonstrated the efficiency of the vibration control.
Numerical Simulation of Boiling Heat Transfer of Water in Vertical Rectangular Mini-Channels
Authors: Guo Lei , Zhang Shu Sheng , Chen Ya Qun , Cheng Lin
Published: September 2010

Boiling heat transfer in vertical rectangular mini-channels with a width of 1mm and 0.1mm is studied in this paper. The course of bubble generation, growth and departure is numerically simulated and analyzed, and the influence of the movement of phase interfaces on pressure difference and average surface heat transfer coefficient is investigated by using geometry reconstruction and interface tracking. All the calculation is conducted taken into account the gravity, surface tension and wall adhesion. This paper presents that the width of channels plays a significant role in the course of bubble generation, growth and motion, which also leads to changes of critical heat flux. In addition, it is found that surface tension is much more important than gravity in the process of boiling heat transfer. As the channel size is decreased, the boiling heat transfer coefficient increases significantly, which proves that mini-channels can enhance the heat transfer. However, the boiling heat transfer coefficient obtained through numerical simulation is higher than the existing experimental data due to the ideal assumptions adopted in simulation.
Experimental Study on High Frequency Short Pulse Electrochemical Mechanical Finishing
Authors: Zhang Yun Peng , Guo Jian She , Sun Guang Biao , Zhang An Zhou
Published: September 2010

The machining process produces surfaces that require some form of finishing operation to improve the surface quality. Aiming at the problem of effective finishing for rough surface, the two stages high frequency short pulse electrochemical mechanical finishing (PECMF) technology is proposed. The composition of test equipment and principles of constant pressure regulating in flat and curve surface finishing process are discussed respectively, and the electrochemical finishing device and a series of cathode tools are designed. Systematic process parameters experiment for superalloyGH188 is carried using Taguchi methodology, the technology rule of process parameters on surface roughness is analyzed and a set of optimized process parameters were obtained. The results have shown that the constant pressure PECMP technology can significantly improve the surface roughness to Ra0.2175μm. The interaction effect between electrochemical anodic solution and mechanical polishing is important for improving the surface roughness in high frequency short pulse electrochemical mechanical finishing process.
Experimental and Numerical Study on Unreliability of Young’s Modulus Measurement by Conventional Split Hopkinson Bar
Authors: Mao Yong Jian , Li Yu Long , Wang Rui , Guo Wei Guo , Shi Fei Fei
Published: September 2010

The split Hopkinson bar (SHB) technique has been widely used to determine dynamic plastic/damage properties of materials at high strain rates. But presently, a number of researchers used it to measure the so-called dynamic Young’s moduli. This paper aims at the feasibility to determine Young’s moduli by conventional SHB. The strain-stress curves of two kinds of metals, 45# steel and LY-12 aluminum, were measured by a conventional SHB facility. The corresponding numerical experiments were performed by ABAQUS/Explicit. The curves obtained by the both procedures agree well in elastic stage (strain range 0-0.5% assumed). But the slopes of the linearly fitted curves, i.e. the so-called dynamic Young’s moduli, are much different from the corresponding real values. The significant errors come from the non-uniformity of stress in specimen during the beginning stage of loading process. The results clarify that it is unfeasible to measure Young’s moduli by conventional SHB.
Research on Intelligent Fault Diagnosis Method for ESP Protector Based on Fuzzy Petri Nets
Authors: Li Lan Yun , Yang Zhuan Zhao , Li Xiao , He Zhi
Published: September 2010

The protector is a key part of electric submersible pump (ESP), seals the motor and prevents the water entering into it. In order to solve the problem of complexity and uncertainty of fault propagation and analysis in protector, a new method for ESP protector fault diagnosis based on Fuzzy Petri nets (FPN) is proposed. Firstly, according to expert experiences and maintain rules, the FPN structure which has 28 places and 11 transitions is built to describe the protector fault propagation relations. Secondly, the five matrixes representing the FPN structure are obtained, and a rapid fault inference algorithm is designed via matrix operations. Finally, two fault diagnosis cases are analyzed, and the results show that the proposed method is valid and has strong engineering practicality.
Crack Analysis of Induction Heating Bent Pipe
Authors: Yang Zhuan Zhao , Liu Dao Xin , Zhang Xiao Hua
Published: September 2010

There were 20 of 103 length of pipe found cracks on the extrados surface of the bent pipe made of Φ406.4×10mm L360 Longitudinal Submerged Arc Welding (LSAW) pipe, the cracks were mostly distributed in the extrados surface and the arc initial point of the bent pipe, the cracks were spindle-shaped and narrow at both ends with the longitudinal direction vertical to the axis of bent pipe. The mechanism and the causes of the cracks were studied by macro inspection, mechanical property test, microscope, scanning electron microscopy and energy spectrum analysis, which shown that the cracks were result from the contamination of copper or its alloy during or before the bent pipe production. The contaminated material like copper infiltrated and diffused into the base metal at high temperature, and could hardly stead to and transfer the normal stress from the base metal where the inertial crack was shaped. Meanwhile, the new crack was formed at the tip of inertial crack after the new infiltration and diffusion under the condition of both high temperature and tensile stress, so that the crack progressed and extended in this way.
Simulation and Experiment of Three-Phase Inverter Based on SVPWM
Authors: Wu Zhi Hong , Chen Guo Qiang , Zhu Yuan , Tian Guang Yu , Fan Liu Qun
Published: September 2010

Aiming at the simulation of the three-phase inverter and SVPWM, the paper introduces their principles. A new method to build SVPWM simulation block in MATLAB/Simulink is proposed. The on-voltage-drop of the power devices is taken into account; the switch and diode are modeled as the connection in series of a resistance and a voltage source in simulation. The simulation and experiment results verify the correctness of simulation models, and show that the on-voltage-drop of the power devices has effects on the phase current and phase/line voltage, especially when the inverter works at a light load state.
Handling Stability Performance Simulation and Analysis of Three Different Vehicle Models
Authors: Wang Shu Feng , Li Hua Shi , He Cui Hua
Published: September 2010

In order to obtain accurate vehicle handling stability performance, 2 DOF nonlinear vehicle model and multi-body dynamics vehicle model are established. Selecting the same vehicle parameters, step steering angle input simulations of three vehicle model (include 2DOF linear vehicle model) are carried out under the same driving conditions, simulation results are analyzed and compared. The simulation results show that 2DOF linear model can characterize the steering states of vehicle when vehicle lateral acceleration is small, but when vehicle lateral acceleration is big, Nonlinear vehicle model and multi-body dynamics model is accurate.
Design of Stereo Frequency Modulation Exciter Controlled by Microcontroller
Authors: Zhang Jian Bin , Zhu Ming Fang , Ren Yan Ling , Lu Jian
Published: September 2010

A new stereo Frequency Modulation exciter scheme for short-distance wireless communication is proposed. It adopts a stereo FM IC BH1415 to transmit audio FM signals, and its transmitting frequency is controlled by microcontroller. The basic principle of phase-locked loop for FM is analyzed, and the audio FM circuit based on BH1415 and the controlling method based on AT89C51 are introduced. Test results indicated that, the audio FM Exciter had simple structure and higher reliability, each parameter can meet the demands of FM broadcasting system, and it has some scalability.
Research on the Improvement of Wireless Network TCP Integrated Mobile IP
Authors: Jiang Yi Feng , Sun Yu , Hu Lin Na
Published: September 2010

TCP is the most widely used protocol in internet which provides the reliable end to end data communications for users, and the TCP congestion control is one of the key technology that ensures the internet normal functions. However, TCP was designed on the terms of wire network at first, in which congestion was the only reason for division lost and accordingly TCP control was made. In the wireless network there are many error codes, the transfer mistakes easily make division lost and the network congestion is not the only reason for data lost any more, so if we continue to use the traditional TCP control, the transfer speed and the network function will be down. This paper offers a DS-TCP solution based on mobile algorithm that can efficiently reduce the data packet lost in the wireless network, increase the TCP throughput and network utilization and improve the TCP functions in the mobile IP wireless network.
MEMS Gyroscope Random Error Modeling and Filtering
Authors: Ren Bo , Zhang De Ming , Li Huan
Published: September 2010

MEMS gyroscope is a new type of inertial device with small size, low cost, light weight, high reliability, but less precise and random error is relatively large. In this paper, from a practical engineering application point of view, first, the MEMS gyroscope random errors is real-time average filtered. Then, based on the basic principle of time series analysis of random sequence , the first-order AR model of MEMS gyroscope random errors is established. Finally, based on Markov characteristic of kalman filtering algorithm, each output of the MEMS gyroscope is multiple real-time filtered. Through the specific data processing, MEMS gyroscope random errors reduced to about two per cent of the original.
Failure and Deformation Modes of Sandwich Beams under Quasi-Static Loading
Authors: Jing Lin , Wang Zhi Hua , Zhao Long Mao
Published: September 2010

In this paper the structure response of quasi-statically loaded sandwich beams made of aluminum skins with open-cell aluminum foam cores is investigated experimentally. The experimental programme was designed to investigate the deformation and failure modes of sandwich beams, so a large number of experiments have been conducted, and the experimental results are reported and discussed systematically. It is found that sandwich beams under quasi-static punching loads can fail in several modes: face yield, face wrinkling, core shear, the bottom face fracture and interfacial failure between the core and the faces. Moreover, the effects of face thickness, cell size of foam material on the failure and deformation modes were discussed. The experimental results are of worth to optimum design of cellular metallic sandwich structures.
Simulation of BLDCM Speed Control System Based on PI Controller with Fuzzy Parameter Regulators
Authors: Song Peng Yun , Zhang Ji Ye , Zhang Ke Yue
Published: September 2010

A permanent magnet brushless DC motor speed control system based on PI controller with fuzzy parameters regulators is studied in this paper. First, the simulation models of motor body, inverter, PWM and logic commutation are established, and the generators of Back-EMF and hall signal are obtained by means of s-Function to improve the simulation speed and accuracy; secondly a PI controller with fuzzy parameters regulators is given; lastly designs of the fuzzy controller and of the traditional PI controller are compared with each other by the MATLAB/SIMULINK emulation. The result shows that the simulation model can simulate the actual motor well, and the PI controller with fuzzy parameters regulator is obviously superior to the traditional PI controller in both dynamic and steady-state performance.
Study on the Influence of Non-Newtonian Characteristics on Robots for Medical Application
Authors: Liu Jian Ping , Zhang Xin Yi , Jia Qing Xuan
Published: September 2010

Considering lumen elastic deformation, Reynolds equation is deduced based on non-Newtonian model in this paper. Traction force and hydrodynamic mucus film thickness are calculated according to elastohydrodynamic lubrication theory. Compared with results based on Newtonian model and experiments, analysis based on non-Newtonian model reflects practical condition well. Lumen elastic deformation has some influence on traction force and mucus film thickness.
Study on Simulation of EDM Milling Technology Based on MATLAB
Authors: Zhang Yun Peng , Zhao Wei , Zhang An Zhou
Published: September 2010

Due to the complexity of electrical discharge machining (EDM) milling technology, an artificial nerve network simulation and prediction model based on MATLAB for EDM milling technology is proposed. The three -layer BP neural network model is built by applying MATLAB technology and combining with the database toolbox and artificial neural network toolbox in MATLAB, it has the ability of getting experimental data from EDM milling technology database and calculating by neural network and then outputting the prediction result. Finally, the model is used to simulate the relations between material removal rate (MRR), surface roughness and process parameters, and analyzed the technological rule. It is proved that the prediction error is controlled within 10% and the simulation result can successfully map the technological rule of EDM milling technology.
Research of a Rotating Machine Reconfigurable Monitoring System
Authors: Wan Jian , Wang Tai Yong , Yuan Yi
Published: September 2010

To get over the problem that only one type of filter cannot meet the requests of field monitoring, a rotating machine monitoring system that can reconstruct filter type was developed based on ARM, DSP and FPAA. The dual-CPU consisted of ARM and DSP was used as the computing and control core of the system; FPAA was used to achieve that the filter type can be reconfigured; RT-Linux was imported as embedded real-time operation system, which achieved hiberarchy design of software and enhanced the operational stability and real-time performance of task assignment. Put into practice, it was confirmed that the system was effective.
Numerical Analysis of Internal Flow in Mufflers with Complex Structures
Authors: Zheng Zhong Cai , Liu Na , Li Jian , Gao Yan , Chen Hai Ou
Published: September 2010

This paper builds three-dimensional finite volume models for 4 different mufflers. Internal flow numerical analysis for mufflers is carried out with computational fluid dynamics software. Velocity field and pressure field are obtained to analyze the airflow influences on muffler performances. The corresponding regularities are obtained from simulation results, which provide a method for design optimization of mufflers.
Evolutionary Optimization Design of the Structural Dynamic Characteristics under Multi Constraints
Authors: Mao Zhi Ying , Chen Guo Ping , He Huan
Published: September 2010

This paper studies structural topology optimization, and the position of mode shape nodal lines is introduced to the equation as a constraint firstly. It builds the sensitivity equation of the position of mode shape nodal lines and frequency. Thereafter, the element deletion criterion with frequency and position of mode shape nodal lines constraints is afford. Then on the base above, it provides the fit path of topology optimization with constraints of frequency and the position of mode shape nodal lines. Finally, a numerical example demonstrates that the method used in this paper is effectively.
A Novel Centroid Particle Swarm Optimization Algorithm Based on Two Subpopulations
Authors: Wang Yong Sheng , Li Jun Li , Lou Yang
Published: September 2010

This paper proposed the concept of centroid in particle swarm optimization which is similar to physical centroid properties of objects. Similarly, we may think of a particle swarm as a discrete system of particles and find the centroid representing the entire population. Usually, it has a more promising position than worse particles among the population. In order to verify the role of centroid which can speed up the convergence rate of the algorithm, and prevent the algorithm from being trapped into a local solution early as far as possible at the same time, A Novel Centroid Particle Swarm Optimization Algorithm Based on Two Subpopulations(CPSO) is proposed. Numerical simulation experiments show that CPSO by testing some benchmark functions is better than Linear Decreasing Weight PSO (LDWPSO) in convergence speed in the same accuracy of solution case.
Kinematics Analysis of a Parallel Robotic Manipulator
Authors: Huang Xi Guang , He Guang Pin , Li Duan Ling
Published: September 2010

The parallel robotic manipulator has attracted many researchers’ attention and it also has growing applications to different areas. In this paper an algebraic method for solving the direct kinematics analysis problem for a parallel robotic manipulator. Based on the presented algebraic method, the problem is derived into a 40th degree univariate polynomial. All complete sets of 40 solutions to the problem are obtained. The proposed method is exemplified by a numerical example.
Green Design and Manufacturing in Electromechanical Product
Authors: Li Gong Fa , Kong Jian Yi , Jiang Guo Zhang , Zhao Gang , Xie Liang Xi
Published: September 2010

Green design and green manufacturing are new design concepts, involving a sustainable development strategy in manufacturing. Definitions of green design, green manufacturing and green product are given. The principles of green design are put forward. It is pointed out that green design and green manufacturing in electromechanical product are developing trends in electromechanical manufacturing. Trends in the green design and manufacturing in electromechanical product are discussed concerning globalization, socialization, integration, parallelism, intelligence and industrialization.
A New Impulse Grounding Resistance Measuring Instrument
Authors: Dai Wen Jin , Wang Kai
Published: September 2010

This paper introduces a convolution calculation method first, and thus to design a portable shock resistance measuring instrument. With the MATLAB simulation of software and field measurements of the measurement instrument, obtain the satisfactory results, thus proving the usefulness of this method.
Adsorptive Removal of Dibenzothiophene in Diesel Fuel on an Adsorbent from Rice Hull Activated by Phosphoric Acid
Authors: Yu Guo Xian , Sun Jing , Hou Xiao Ming , Zhou Xiao Long , Li Cheng Lie , Chen Li Fang , Wang Jin An
Published: September 2010

Rice hull (designated with RH) was activated by phosphoric acid to prepare an adsorbent for the removal of sulfur-containing compounds from diesel fuel. Adsorption tests for both, a 300 µg.g-1 dibenzothiophene (DBT)-containing n-octane solution using as model oil and a commercial hydro-treated diesel fuel, were performed to elucidate the effect of varying phosphoric acid to RH ratio, treating temperature and the removal of silica from the adsorbent on the combination of the textural structure, surface chemical property and adsorption capacity. It was indicated that high surface area and micro-pore volume of the adsorbent favored the adsorption of DBT and its derivatives. Richening of oxygen-containing compounds on the adsorbent surface was advantageous to the adsorption and removal of DBTs. At a phosphoric acid and RH weight ratio of 3:1 by using a two-step treatment, a satisfactory adsorbent with an adsorption capacity of 28.89 mg S/g was successfully prepared. If the silica in the adsorbent was further removed, the product exhibited the highest performance, reaching 30.43 mg S/g for the model oil and 21.79 mg S/g for the commercial diesel fuel. Both the textural structure and the surface chemical property like acidic groups of a RH-based adsorbent play important roles in its adsorption behaviors, and the formation of donor-acceptor complexes between surface acidic groups and DBT may probably benefit DBT adsorption capacity.
Yb2O3 Promoted Pt-SO42-/ZrO2-Al2O3 Catalyst in N-Hexane Hydroisomerization
Authors: Yu Guo Xian , Hu Yang , Lin Da Ni , Zhou Xiao Long , Li Cheng Lie , Chen Li Fang , Wang Jin An
Published: September 2010

Effects of ytterbia for Pt-SO42-/ZrO2-Al2O3-Yb2O3 (PSZAY) catalysts in n-hexane hydroisomerization were investigated. It was elucidated that the introduction of ytterbia into Pt-SO42-/ZrO2-Al2O3 (PSZA) increased both the surface area and the number of active sites, resulting in a higher n-hexane isomerization activity. At the same time the catalyst stability has also been markedly increased by alleviating the sulfur loss and by stabilizing ZrO2 tetragonal crystalline structure.
Basic Ion Exchange Resins as Heterogeneous Catalysts for Biodiesel Synthesis
Authors: Falco Marisa G. , Córdoba Carlos D. , Capeletti María R. , Sedran Ulises
Published: September 2010

Basic and acidic ion exchange resins were used as catalysts for the synthesis of biodiesel from soybean oil and methanol. The impact of reaction parameters like molar methanol/oil relationship, catalyst mass and reaction temperature were studied. The catalysts did not show deactivation and the reaction medium remained neutral. The performance of the resins was compared against reference catalysts (NaOH; MgO). A strongly basic macroporous resin was the most active catalyst and it was possible to reach 100 % selectivity to methyl esters. A series reaction mechanism was consistent with the evolutions of the intermediate reaction products.
Role of Nanocrystalline Titania Phases in the Photocatalytic Oxidation of NO at Room Temperature
Authors: Castillo S. , Carrera R. , Camposeco R. , Del Angel P. , Montoya J.A. , Vázquez A.L. , Morán-Pineda M. , Gómez Ricardo
Published: September 2010

Nanocrystalline TiO2 powders were prepared by the sol-gel method and evaluated in the NO photocatalytic oxidation. Samples annealed at 200 and 500°C (TiO2-P-200, TiO2-P-500) were characterized by nitrogen adsorption, XRD-Rietveld refinements, TEM, FTIR and UV-vis spectroscopies. The photocatalytic test of the sol-gel TiO2 samples was carried out in an insulated chamber with 10 ppm of NO, using a 365-nm UV light lamp; the test results were compared with those obtained with a commercial catalyst (P25). Improved photoactivity (89 % of NO oxidized in 60 min) was obtained with the TiO2-P-200 solid which showed high surface area, small crystallite size, higher amount of OH and highly abundant brookite phase (37.2 %) coexisting with the anatase phase (62.8 %). The photo-oxidation activity of the sol-gel catalyst annealed at 500 °C (TiO2-P-500) showed changes in its textural and morphologic properties and therefore, less photoactivity. Sol-gel photocatalysts could be a good option for abating pollution in both indoor and outdoor environments at room temperature.
Ultraprecision ELID-Grinding of Aspheric WC Lens Mold for Plastic Injection Molding
Authors: Nemoto Akihiko , Ohmori Hitoshi , Murata Yasuhiko , Itoh Nobuhide
Published: September 2010

To cope with increasing demands on ultraprecision profiling and finishing of aspheric lens
molds, we have implemented an ultra/ nanoprecision aspheric grinding system to be mounted with an
ELID- capability and on-line feedback capability of profile accuracy. A WC mold has successfully
ground and finished to be with several nanometric surface smoothness and with ultraprecise profile
accuracy by just grinding process with ELID mechanism. Some specific conditions have been
investigated to achieve better accuracy and quality on molds. This paper presentation introduce those
R&D activities and also discuss on the latest achievements on this topics, with showing injected
aspheric lenses by the molds.
Effects of Electrolyte Formulas on Electrochemical Polish Planarization of Pure Copper
Authors: Huang J.C. , Weng Yung Jin , Weng Yung Chun , Chan Y.F. , Liu Hsu Kang , Fang H.S.
Published: September 2010

Electrochemical polish technology could enhance the chemo-mechanical polishing
efficiency of copper material. During the electrochemical polishing process, both the components
and operation parameters of electrochemical polish solution are the key factors influencing
planarization ability. This work measured the surface topography and roughness of copper material
after mechanical polish by an atomic force microscope (AFM), and added glycerol in different
ratios to the phosphoric acid (85 wt %), which was the main composition of experiment solution.
Electrochemical polish was conducted within the potential action range in passivation area, and the
surface topography and roughness of copper material after electrochemical polish was measured by
AFM. The difference in surface topography of copper material after electrochemical polish was
compared as well.The experiment indicated that after electrochemical polish in pure phosphoric
acid for 50 sec, the surface roughness of copper material obviously decreased from 6.921nm (Ra)
to 0.820nm (Ra), and the planarization was more obvious with the increase of electrochemical
polish time. The above results could appear in different electrolyte formulas, indicating that
electrochemical polish was a good processing method for copper material planarization. This work
also proposed the effect of analyzing the electrochemical polish time on planarization through
planarization efficiency. Based on the analysis, the planarization efficiency was decreased with the
increase of electrochemical polish time, which indicated that longer electrochemical polish time did
not yield better result. This work also found that the surface is not only flattened, but also glossed
after electrochemical polish.
Focused Ion Beam Nano-Precision Machining for Analyzing Photonic Structures in Butterfly
Authors: Wang Hou Xiao , Zhou Wei , Li Er Ping
Published: September 2010

Nano-precision machining using focused ion beam (FIB) is widely applied in many fields. So far, FIB-based nanofabrication for specific nanoscale applications has become an interesting topic to realize more diversities for nano-construction. Through FIB machining, we can easily achieve the required nano- and micro-scale patterning, device fabrication, and preparation of experimental samples. Nowadays, there is an increasing trend to learn from nature to design novel multi-functional materials and devices. Thus, more interestingly, another advantage of FIB is that it can be conveniently used to analyze the natural photonic structures, e.g., those in the butterfly which exhibits amazing optical phenomena due to sub-wavelength structural color. Accordingly, in the present study, structural analyses for butterfly wings were carried out using FIB. It is found that the photonic structures for the backside and frontside of the butterfly wing studied differ considerably. The difference accounts for the different colors on the dorsal and ventral sides of butterfly wings.
Ductile and Brittle Mode Grinding of Fused Silica
Authors: Yao Peng , Yoshihara Nobuhito , Hitomi Nobuteru , Yan Ji Wang , Kuriyagawa Tsunemoto
Published: September 2010

There is a demand for high-efficiency and high surface integrity grinding of fused silica. Ductile grinding is an ideal method for producing a mirror finished surface on hard and brittle materials to significantly decrease polishing time. However, the fused silica is still difficult to ductile grind because of its high brittleness. A creep feed taper grinding method was applied to investigate the relationship between maximum grit depth of cut and surface integrity of fused silica. Ductile mode grinding was achieved on fused silica. When the depth of cut exceeds the critical wheel depth of cut, the surface suddenly changes from the ductile mode to the brittle mode. At the same ratio of wheel speed and table speed, the critical wheel depth of cut is noticeably increased by increasing the wheel speed which caused an increase in the temperature at the interface of grains and workpiece. The depth of subsurface damage (SSD) was investigated by polishing the ground surface. The experiment results show that the depth of SSD is deepest in transition mode and stables in brittle mode.
Fabrication of Damage-Free Curved Silicon Crystal Substrate for a Focusing X-Ray Spectrometer by Plasma Chemical Vaporization Machining
Authors: Hosoda Mao , Ueda Kazuaki , Nagano Mikinori , Zettsu Nobuyuki , Shimada Shoichi , Taniguchi Kazuo , Yamamura Kazuya
Published: September 2010

In the X-ray fluorescence analysis on sub-micron particle, application of the doubly curved crystal (DCC) spectrometer with Johansson-type geometry is effective to improve the lowest limit of detection because DCC makes it possible to focus and monochromatize an X-ray beam simultaneously. A strain-free crystal is essential for the high-performance focusing crystal spectrometer. We propose the application of the open-air type numerically controlled plasma chemical vaporization machining (NC-PCVM), which utilizes neutral reactive species generated by atmospheric pressure plasma, to fabricate the DCC substrate. By applying NC-PCVM technique, a curvature radius error of 0.08% was obtained, and there was no degradation of the crystallinity of the Si (111) substrate.
Micro-EDM for an Aluminium Matrix Composite
Authors: Hu Fu Qiang , Song Bo Yan , Bai Ji Cheng , Hou P.J. , Chen H.C. , Zhang H.
Published: September 2010

The silicon carbide particle reinforced aluminium matrix composite (SiCp/Al) which is acknowledged as one of the most competitive metal matrix composites is now widely applied in aviation, aerospace and military fields, and its application is extending gradually. As a result of the hard and brittle SiC particles contained, mechanical machining of the material is difficult, but the method of electric discharge machining (EDM) has certain prominent advantages. In this paper, SiCp/Al was machined using micro-EDM. First, a Ф40μm × 4.1mm micro tool electrode of which the aspect ratio is up to 100 was made; and then, through experiment, the impact of open-circuit voltage and electrode material on processing speed and electrode wear was analyzed; finally, 28μm wide micro slits, micro square platform of 34μm long on each side and other micro three-dimensional structure were machined. Research and experimental results show that the use of appropriate micro-machining parameters and reasonable processing methods can improve processing performance to better achieve the micro-EDM of SiCp /Al.