bluuebunny/crossref_metadata_2025 huggingface dataset:
Decentralized Linear Permanent Magnet Synchronous Motor Control Using Harmonic Injection SPWM
Authors: Tang Zi Li , Hao Shuang Hui , Hao Ming Hui
Published: September 2012

This paper proposes a novel SPWM with harmonic injection method to improve the utilization ratio of bus voltage of decentralized LPMSM. In a traditional SPWM, usually, the phase voltage order is restricted independently, which results in that the bus voltage can not be used efficiently, produces voltage vector direction error, and lowers response frequency of current cycle. To solve this problem, the proposed method adopts pulse width modulation control technology with active harmonic injection to enhance the utilization ratio of bus voltage, and the theoretical analysis has been conducted from the potential difference point of view. The final results show that this method can enhance the utilization ratio of bus voltage of the high power LPMSM greatly, and improve current control, under the premise that voltage vector accuracy is not affected. This result confirm the validity of the proposed method.
Genetic Algorithm Solving Capacitated Automatic Guided Vehicle System for Scheduling Problems
Authors: Gu Hong , Xu Wei Hua , Zou Ping
Published: September 2012

In this article, through the in-depth analysis of handling techniques of scrap material in a cigarette factory and working trait of automatic guided vehicle (AGV), and considering the capacitated of AGV transportation, a new scheduling policy is proposed for its transit of the scrap in one manufacture unit, a capacitated GA model is also proposed to solve AGV scheduling problems. Based on self-learning and the improved GA, and considering the compromising solutions for the capacitated of AGV, the real-time scheduling policy of AGV is provided. The rule of encoding, selecting, crossover selection and variation probability is studied. The results of the simulation calculation and application in the cigarette factory have been effectively improved, and the example proves that the research is feasible and effective.
Dynamic Responses of Mobile Elevating Work Platform and Mega Container Crane Structures
Authors: Bošnjak Srđan M. , Zrnić Nenad Đ. , Gašić Vlada M. , Petković Zoran D. , Milovančević Milorad Đ.
Published: September 2012

The modern design methods lead to the objectivisation of the process of thinking, which is important for the new system development. The aim of objectivisation and decomposition of the design is obvious: it should enable a new approach in the problem solving and thinking of the designer, enriches the large quantity of new information, facts and ideas, which are important for the system designing. The first part of this paper gives a brief presentation of mobile elevating work platform structure response to the wind excitation in possible resonant states. The second part is dedicated to the dynamic analysis of the mega container crane structure subjected to the moving load.
Mechanism Analysis of Local Collapse in an Underground Powerhouse Based on Strength Reduction FEM and DEM
Authors: Zhang Jian Mei , Fei Wen Ping , Zhang Zheng Dao
Published: September 2012

Large collapse of underground house of a hydroelectric power station happened while excavation of the top arch. The volume of collapse was up to 5000m3. With consideration of the field geological conditions and practical construction, by strength reduction finite element method (FEM) and discrete element method (DEM), the process of collapse is simulated, which is compared with the field monitoring data. The mechanism of instability failure is analyzed. Some conclusions are obtained. Firstly, the development of fractured weak zone β80, faults, joints and fissures above the top arch are the basic factors to induce this collapse. Secondly, abrupt blasting without supporting is the direct factor. So collapse of underground house can be avoided by reinforcement and supporting on the geological weak zone in time.
An Improvement on Randomly Changed Identification Protocol for Low-Cost Tags
Authors: Tao Xiao Xia , Yang Hong , Chen Rong , Du Zhen Jun
Published: September 2012

With the benefits to improve productivity and reduce operation cost, RFID (Radio Frequency Identification) has recently seen a great increase in a wide variety of business information systems. However, the downside in business applications is the problem caused by data security and privacy. Enhancement without extra costs in RFID identification poses new challenges to privacy and security in RFID-driven just-in-time business information systems. In this paper, we propose an unilateral randomly authentication protocol on the basis of one-way hash function for low-cost RFID tags. We illustrate the whole operating procedure of the proposed protocol in a typical RFID system. Experimental results show that the proposed protocol has some security improvements in data consistency and can work against some attacks like eavesdropping and DoS, compared with several existing methods.
Analysis on Electronic Differential Control Strategies of Electric Vehicle
Authors: Li Cheng Qun , Zhou Cui Yu
Published: September 2012

Based on the relationship between the motor torque of each side and electric current when the electric vehicle turns, this article puts forward a control scheme of electronic differential which is used to regulate current and control torque, according to the micro electric vehicle with a double-wheel motor driven. In addition, the article makes detailed analysis for the electronic differential control process.
CFD Simulation and Experimental Study on Solid-Liquid Hydrocyclone
Authors: Huang Si , Le Yue , Li Luo
Published: September 2012

This paper presents a numerical simulation and experimental study on a solid-liquid hydrocyclone. In the simulation, the standard k-ε turbulence model and the zero-equation model are employed to compute the flow field of the two phases in the hydrocyclone under different conditions, such as viscosity of the liquid, particle size and flow rate. In the experiment, a hydrocyclone is manufactured and measured for the separation efficiency and pressure drop in the test system. The simulation result of hydrocyclone performance matches well with the experimental data.
The Influence of Data Imbalance on Feature Selection
Authors: Li Yan Ling , Han Kui Xia , Zhu Ye Hang
Published: September 2012

Data imbalance problem is urgent problem in data mining and machine learning fields, the standard classifier will tend to over-adapt to the large categories and ignore the small categories. According to this problem, this paper takes two categories of text classification problem as the background, respectively from the amount of text and the text length two perspectives, compare the impact of data distribution imbalance on different feature selection methods, and based on this we attempt to improve feature selection methods by set threshold according to category, through a series of experiments and results analysis, get some practical conclusions.
Decision Approach of Multi-Agent Intelligent Decision Support System Based on Blackboard
Authors: Sun Yong Yong
Published: September 2012

Multi-Agent Intelligent Decision Support System based on blackboard is designed that uses of blackboard system and Agent, it describes the framework and gives the detail about the each Agent. At the same time, decision algorithm based on rough set of system is provided, and its application is described. The system can help to cooperate in Multi-Agent about complicated works.
The Research to Image Enhancing Method of Infrared Images
Authors: Han Kui Xia , Li Yan Ling , Yu Mei
Published: September 2012

The contrast is low, and the noise is strong in infrared images, which go against defects judgment and recognition. In order to resolve them, limitations of common methods were analyzed, then, according to characters of infrared images and processing target, grayscale value adjustment method and low pass filter method was introduced. Designed image enhancement steps, and it was applied to process thermal image. In process of index low-pass filtering, the cut-off frequency selection was studied. And, it was found, when it was 40, the effect was ideal. Compared the original image with image after treatment, the validity of this method was verified. There an effective way was designed for heat waves image enhancement.
Failure Behavior Tests of Preloaded T300/AG80 Composites Irradiated by Laser Beam
Authors: Liu Li Ting , Long Lian Chun , Chen Zhong Ying
Published: September 2012

This paper predicts the effect of main parameters to the failure behavior of T300/AG80 composite plate under preload and laser irradiation by experimental testing and data fitting. The load holding device was used to give certain preload to composite plate specimens, and an Nd: YAG laser was used to give laser radiation simultaneously for testing the failure time of the specimens. By varying the magnitudes of preload and the laser power densities, the effect of preload and laser power density on the failure time is obtained. The reaction process was recorded with a high-speed camera. The experimental data were fitted to obtain the expression of the materials failure time with preload and laser power density. When the preload kept constant, the relationship between the failure time and laser power density was exponential function. When the laser power density kept constant, the relationship between the failure time and pre-tensile-loads was approximating linear, and pre-compress-load was quadratic. Fitting the empirical formula provides a reference to predict life for the composite structure applied both preload and the action of the laser irradiation.
Influence of Deposition Time on ZnO Films Grown by RF Magnetron Sputtering
Authors: Ma Zi Jun
Published: September 2012

ZnO thin films were prepared on glass substrates by radio frequency co-reactive magnetron sputtering at different deposition time of 20, 40, 60 and 80 min. Surface morphologies and crystal structures were examined using atomic force microscopy and X-ray diffraction. As the deposition time increased to 60 min, surface morphologies of the films became smooth and distributed uniformly. The crystallinity along the c-axis improved as the deposition time increased. The photoluminescence (PL) studies indicate that three main emission peaks located at 439nm, 483nm and 525nm were observed. The intensity of 439nm emission increased to maximum as the deposition time was 80 min, while the intensity of green emission band (from 483 to 525nm) attained to maximum as the deposition time increased to 60 min.
Microcontroller Based Single Axis Intelligent Control Sun Tracker for Parabolic Trough Collectors
Authors: Akram Shakeel , Malik Farhan Hameed , Liao Rui Jin , Liu Bin , Nazir Tariq
Published: September 2012

Due to the complex design and high costs of production, solar thermal systems have fallen behind in the world of alternative energy systems. Different mechanisms are applied to increase the efficiency of the solar collectors and to reduce the cost. Solar tracking system is the most appropriate technology to increase the efficiency of solar collectors as well as solar power plants by tracking the sun timely. In order to maximize the efficiency of collectors, one needs to keep the reflecting surface of parabolic trough collectors perpendicular to the sun rays. For this purpose microcontroller based real time sun tracker is designed which is controlled by an intelligent algorithm using shadow technique. The aim of the research project is to test the solar-to-thermal energy efficiency by tracking parabolic trough collector (PTC). The energy efficiency is determined by measuring the temperature rise of working fluid as it flows through the receiver of the collector when it is properly focused. The design tracker is also simulated to check its accuracy. The main purpose to design this embedded system is to increase the efficiency and reliability of solar plants by reducing size, complexity and cost of product.
Multiple Data Acquisition System Based on the AT89S52
Authors: Dong Xue Dong , Ma Jun , Liu Yan , Wang Wei , Ye Peng
Published: September 2012

The paper designs a multiple-data acquisition system based on the AT89S52. The system consists of two-way series A/D converter ADC0832, SCM AT89S52, extended 62256 RAM and LED display. It also describes the functional block diagram of system design, hardware interface schematics for each block and the software flow chart. By the acquisition, processing and display to the two road voltage signals, the results show that the system can realize the real-time data acquisition, processing and display for the multiple data, which has better versatility and can be widely used in the field of industrial automatic control.
The Fretting Wear Property of Grease Containing Antiwear Nanoparticles Additives
Authors: Wang Jiu , Chen Bo Shui , Fang Jian Hua , Wu Jiang
Published: September 2012

First the fretting wear behavior of CuS nanoparticles additives in grease were studied. The results show that the fretting wear volume reduce significantly when CuS nanoparticles additives add to grease. At the same time the existence of sulfid nanoparticles can reduce friction coefficient at the latter fretting time. The results of XPS tests show that Cu, Zn, Ni, S and B elements were founded in the film of wear scar. Secondly the effect of antiwear and oiliness additives on fretting wear behavior of nanoparticles additives in Grease were studied. It was found that when some antiwear, oiliness additives (such as T203, T322, stearyl alcohol or stearic acid) and sulfide nanoparticles were added to urea grease, a synergy effect between the two types of additives made fretting wear volume more small than that of either additive. Based on the results of contrast experiment and some analysis of fretting wear scars, we present the idea that two additives react with friction surface step by step. That is to say, the high chemical activity of CuS nanoparticles decompose first and form protective layer, the heat converted from chemical reaction of CuS decomposition and mechanical motion promote composition of common oil additives, thus protective layer is formed once again and wear volume further decrease.
A Campus Safety Monitoring System Based on Ad-Hoc Network
Authors: Wang Zhen Chao , Wang Liang , Tian Xiao Yan , Pang Jiao , Huang Yong Ping , Chong Shao Fei
Published: September 2012

This paper introduces a campus safety monitoring system based on wireless mobile communication network. Backbone network of the system is an ad-hoc network based on Opportunity Driven Multiple Access (ODMA) multi-hop relaying protocol, which has the characteristics of wireless relaying, quickly and flexible network formation, dynamic topology etc. The system has the functions of image real-time transmission, the patrol car mobile camera shooting and video signal mobile transmission, and static and mobile wireless Internet access etc.
Research of the Paper Defect On-Line Inspection System Based on Distributed Machine Vision
Authors: Qi Xing Guang , Zhen Yi
Published: September 2012

This paper presents a distributed machine vision inspection system, which has a large field of view (FOV) and can perform high precision, high speed real-time inspection for wide paper sheet detection. The system consists of multiple GigE Vision linescan cameras which connected though Gigabit Ethernet. The cameras are arranged into a linear array so that every camera’s FOV is merged into one large FOV in the meantime the resolution keeps unchanged. In order to acquire high processing speed, the captured images from each camera are sent into one dedicate computer for distributed and parallel image processing. Experimental results show that the system with fine detection capability can satisfy the requirements of real time detection and find out the defects on the production line effectively.
Studies on Detection Device of Polar Components for Quality Evaluation of Frying Oil
Authors: Wang Wei , Wang Yong Wei , Li Zhi Xing
Published: September 2012

A fast, effective polar components detection device for quality evaluation of frying oil was designed. The theory of the device is based on a capacitance sensor which takes the frying oil sample as the media. A sine wave signal that generated by DDS signal generator to excite the capacitance sensor. Then the device exported a voltage value which associated with polar components of the frying oil through the signal conditioning circuit. The experimental data was compared with column chromatography, using MATLAB to solve the data fitting process, the result shows that the correlation coefficient is 0.9817, indicating that the frying oil quality detector method is simple, fast, non-destructive and no solvent.
Research and Application of Coordination Controller in Web Inspection System (WIS)
Authors: Qi Xing Guang , Shen Cai Sheng
Published: September 2012

The study and application of the coordination controller in Web Inspection System (WIS) involves the field of industrial inspection and machine vision technology. The online WIS consists of roller equipment, coordination controller, switch controller, a number of cameras, image management system and management server. Coordination controller based on FPGA design and the LVDS interface, CAN bus interface, is connected through the line with roller equipment, switch controller and a number of camera management server. The CCD camera is connected through the line with image processing systems, and the image processing system connected with management server. Coordinated controller uses a modular design to coordinate control system operation, reduce the CPU load and improve the efficiency of paper defect detection. It is also highly integrated, and able to reduce cabling and costs, so as to raise the efficiency of the controller development, reduce staff workload and improve the working environment.
A Capacitance Based Circuit Design for Yarn Breaking Detection
Authors: Chen Guang Feng , Sun Hao Chun , Zhai Lin Lin , Peng Le Le
Published: September 2012

Yarn breaking is one of the most common problems in textile weaving. Focus on this problem this paper proposed capacitance based detecting-circuit to sense the status of yarn. The sensor adopts a capacitance sensor to detect the yarn on weaving machine. The yarn breaking will lead the little change in electric capacity. To detect the yarn status, Design a 555 based frequency generator circuit with capacitance sensor as one of the input. The pulse generated form 555 circuit is transmitted to MCU, MCU analysis of frequency changes to judge whether the yarn is broken and send relative control signals and location information of yarn breakage to HMI.
The Application of HART Sensor Design in University Teaching Reform
Authors: Xu Wei , Li Dan
Published: September 2012

Because it is less practical value that the students work in computer professional training or graduation thesis, this paper describes a new practical and clear teaching case-- HART sensor design. This paper analyzes the whole system framework design, modem module and serial port module design. The hardware and software systems of these designs are debugged successfully in laboratory environment.
Flame Detection Based on Video
Authors: Tang Yan Yan , Yan Yun Yang , Liu Yian , Gao Shang Bing
Published: September 2012

Flame Detection based on video is an important method for fire prevention. To save flame detection time, the moving objects were segmented from images in a video by using GMM(Gaussian Mixture Model) firstly. Then moving objects were determined as flame candidate or not by their color feature and area changes. The experiments show that the method could detect flame in video effectively with a low false positive rate.
Research on the Variation of Average Temperature of Heat Conduction Process under the Second Boundary Condition
Authors: Wang Yong Yan , Su Chuan Qi , Zheng Hong Cai , Qin Nan , Shi Jia Bin
Published: September 2012

The variation law of the average temperature with time in general case is derived by the differential equation of heat conduction which it is the reflection of the conservation of energy principle. The expression of the average temperature under the second boundary condition is given by the integral form of initial and boundary conditions. And what can be also derived are that the average temperature has a linear relationship with time when the boundary heat flux is constant, and it does not change with time under the adiabatic boundary condition.
Effects of Cryogenic Treatment on Micro-Mechanical Properties of a Cu-Al Alloy
Authors: Wu Lai Lei , Liu Lin , Qi Mai Shun , Liu Jian Hua , Zhang Rui Jun
Published: September 2012

After heat treatment at 800°C for 15min, a Cu-Al alloy was cryogenic treated at -196°C for 30min, the micro-mechanical properties of the Cu-Al alloy before and after cryogenic treatment were measured by nanometer mechanical testing system and the microstructure of the Cu-Al alloy were also analyzed by optical microscope, SEM/EDS and XRD. On the basis of that, the effects of cryogenic treatment on micro-mechanical properties of the Cu-Al alloy were investigated. The results show that the cryogenic treatment can refine the grains, and increase the hardness, elastic modulus, elastic recovery rate and ratio of hardness to modulus of the Cu-Al alloy. As a result, cryogenic treatment can improve the ability to resist applied load and anti-indentation creep effectively.
Study on the Road Rigidity Detecting System Based on LabVIEW
Authors: Yang Shi Feng , Liu Chun Qia , Xu Jing Jing
Published: September 2012

As an important road detection system performance parameter, road rigidity was the key link and the evaluation index of the road detection system. During the construction of road infrastructure, the implementation of road worked on the hardness testing was necessary. The American National Instruments (NI)’s virtual instrument software development platform Lab VIEW was used as the system’s development platform. Through the signal collected by the pressure sensor combined with signal conditioning circuits formed by the single chip, functions of various parts were designed to analyze the relevant parameters of the road rigidity. The test data was measured and collected according to national standard methods, at the same time, virtual instrument software and related algorithms were used to analysis of the statistics data and the state of the road hardness would be detected and researched. And thus it provided an important basis for the quality of road management and road maintenance.
Fabric Defect Detection Based on Local Entropy
Authors: Li Peng Fei , Zhang Huan Huan , Jing Jun Feng , Wang Jing
Published: September 2012

To solve the problem of automated defect detection for textile fabrics, this paper proposed a method for fabric defect detection which is based on local entropy. The method can transform the original gray image space for the entropy space and enhance the different organization structure which is conducive to extract the damage texture region. In the experiment, divided the fabric image to the same size local window, and chosen the smallest value of local entropy window region to segment the defects. The experimental result shown that this method can avoid the whole image complex operations and possess high recognition accuracy.
Fussy Assessment of Fatigue Strength of Spot-Welded Structures
Authors: Yao Yu Xin , Shi Chun Yuan
Published: September 2012

From the point of view of the objective and scientific design of spot-welded structures, each factor that influences the fatigue strength of the spot-welded structure is quantitatively analyzed using fuzzy mathematics. The weighing coefficient is calculated based on the contribution of each factor and their coupling relationship using DARE method. All the influencing factors are divided to two levels, and quantitative assessment result is obtained. Finally, the fatigue life curve of the spot-welded structure is predicted with the utilization of the fatigue life curve of a standard specimen made of the same material.
An Efficient Power Control Algorithm with Dynamic Channel Allocation for TDD/CDMA Systems
Authors: Zheng Zhi Hua
Published: September 2012

Asymmetrical traffic service requirements between uplink (UL) and downlink (DL) will cause serious inter-cell interference in TDD/CDMA system. In this paper, an efficient power control algorithm with dynamic channel allocation (PC/DCA) is investigated, which is based on the average power control algorithms. In the uplink and downlink, PC/DCA scheme is addressed with channel reservation to resolve the interference between base-stations. Simulation results show that the performance of the PC/DCA scheme is improved 20% than that of the traditional DCA schemes for asymmetrical traffic service.
Arc Fault Recognition Method Based on Phase Space Reconstruction and Fractal Theory
Authors: Ma Shao Hua , Bao Jie Qiu , Cai Zhi Yuan , Meng Chui Yi
Published: September 2012

A method of recognize arc fault based on phase space reconstruction and fractal theory is presented in this paper.In order to obtain the current wave under the conditions of different arc faults, the experiment platform is built according to UL1699 standard so as to sample the current wave of arc fault by the digital oscilloscope. Meanwhile the current wave of some electrical equipment with the normal operation are also sampled. The phase space track chart are obtained by the method of phase space reconstruction theory, and the algorithm about extracting characteristic quantity of arc fault current is presented based on the fractal theory. By simulating using MATLAB software, the box-count dimension of the current phase space track charts for arc fault and the some electrical equipment with normal operation are calculated, its result prove this algorithm effective and feasible.
Research of Interpolation Algorithm for Improving the Movement Stability of X-Y Worktable of NC Machine
Authors: Li Jun Min , Wang Jin Ge , Deng Xing Qiao
Published: September 2012

Nonideal iris segmentation is a great challenge in iris recognition, and many researchers have stressed this problem. Since critical step of segmentation is localizing iris center and detecting interior/outer boundaries, we presents a novel method based on EM algorithm to deal with it. EM algorithm is capable of automatic threshold, therefore candidate pupil can be obtained and followed by an innovated fast iris center searching by using strings equilibrium scheme. We also give the region-based outer boundary localization with implementation of order statistical filters (OSF). Experiments demonstrate a high correct segmentation ratio (CSR) of more than 98% has been achieved when using CASIA-IrisV3 Interval and CASIA-IrisV3 Lamp databases.
Stability Analysis for a Class of Linear Switched Positive Systems
Authors: Ding Hui , Lou Xu Yang
Published: September 2012

This paper addresses stability properties of linear switched positive systems composed of continuous-time subsystems and discrete-time subsystems. Based on the common linear copositive Lyapunov functions, stability of the positive systems is discussed under arbitrary switching. Moreover, a sufficient condition on the minimum dwell time that guarantees the stability of linear switched positive systems. The dwell time analysis interprets the stability of linear switched positive systems through the distance between the eigenvector sets. Thus, an explicit relation in view of stability is obtained between the family of the involved subsystems and the set of admissible switching signals.
Multi-Objective Optimization Nonlinear Predictive Control Based on Small-World Optimization
Authors: Wang S.X. , Yang C.H. , Dong Y.
Published: September 2012

Due to fast receding horizon speed and global optimization of small-world optimization algorithm with real-coding (RSW), a new nonlinear multi-objective predictive controller was presented based on RSW and neural network (NN) identification trained by BP. NN model which was obtained by off-line identification was used to predict the present and future output of the plant, and RSW was applied to receding horizon control. Finally, an application to 500MW unit load control system with multi-objective optimization was given, and simulation results indicated the effectiveness of this new approach.
Application of Similarity Theory in Research on Consistency in Multi-Resolution Modeling
Authors: Hou Chun Long , Jiang Yi Shan , Qi Xin Zhan , We Xiang
Published: September 2012

This paper analyzed the function consistency, dominating consistency, state consistency and structural consistency of multi-resolution model based on three principles of the similarity theory. Then, a method of quality evaluation of consistency on state level and structural level are presented. The practice proved that this research is helpful to find the factors which influence the consistency and search for accurate measures to improve the consistency on every level.
One Algorithm for TDOA/AOA Combined Position
Authors: Song Wei Guo , Li Yi De
Published: September 2012

Aiming at the position problem of emitter on the ground, this paper puts forward one TDOA/AOA combined position algorithm. In this algorithm, one sensor can be placed on one fixed platform on the ground to measure the azimuth and pitch angle between this sensor and the emitter. Another sensor can be placed on one moving platform, and the different TDOA (Time Difference Of Arrival) can be measured at different time, then the LS (Least Square) algorithm can be reached to solve the evaluated value of the emitter’s position. The simulation results show that this algorithm can increase the position precision effectively, especially the more TDOA measurements are used, the more position precision is.
An Approach to Advanced XML Constraints Expression and Validation
Authors: Cong He , Jiang Wei Quan
Published: September 2012

XML is widely used nearly everywhere in modern information technology. However, traditional XML semantic constraints expression and validation is still an open issue since grammar-based or rule-based schema languages have built-in limitations in some syntax constraints expression, and the combined ones with more than two languages to check a XML putting a considerable burden on users. A domain-oriented XML expression and validation approach is proposed, which takes high level business concepts to capture the advanced XML constraints in a compact and easy understand way. Some implementation techniques and advantages are also demonstrated to show the lightweight and pragmatic of this approach.
Waveband Selection with Stability for FTIR/ATR Spectroscopic Analysis of COD in Sugar Refinery Wastewater
Authors: Pan Tao , Li Peng Zhao
Published: September 2012

Fourier transform infrared spectroscopy (FTIR) and attenuated total reflection (ATR) technology were successfully applied for the rapid no-reagent determination of chemical oxygen demand (COD) in sugar refinery wastewater. An appropriate waveband with stability was selected by the moving window partial least-squares (MWPLS) regression through a rigorous modeling process. The selected waveband was 3198 cm-1 to 2376 cm-1, the corresponding PLS factor was 5. The modeling effect M-SEPAve, M-RP,Ave, M-SEPStd, and M-RP,Std were 31.5 mg/L, 0.962, 3.9 mg/L, and 0.012, respectively. The validation effect V-SEP and V-RP were 31.9 mg/L and 0.965, respectively. It indicated that the method has good prediction effect and stability, and provided valuable references for designing specialized spectroscopic instruments.
A Study on Ni–TiN Coatings Produced by Ultrasonic Pluse Electrodeposition
Authors: Xia Fa Feng , Ma Chun Hua , Yin Yi Fang , Miao Liang
Published: September 2012

Nanocomposite Ni–TiN coatings were prepared by ultrasonic pluse electrodeposition and the effects of ultrasonication on the coatings were studied. X-Ray diffraction analysis was utilized to detect the crystalline and amorphous characteristics of the composite coatings. The surface morphology and metallurgical structure were observed by scanning electron microscopy, high-resolution transmission electron microscopy and scanning probe microscopy. The results show that ultrasonication has great effects on TiN nanoparticles in composite coatings. Moreover, the introduction of ultrasonication and TiN particles led to the formation of smaller nickel grains. The average grain diameter of TiN particles was 33 nm, while Ni grains measured approximately 53 nm.
Study on Power Generation Experiment Using the Ferriferous Oxide Magnetic Fluid
Authors: Xu Shuang Yan , Li Ming Jun
Published: September 2012

Recently, MHD is a high-efficiency and non-pollution technology. In Xiangtan University a power generation experimental set-up using the ferriferous oxide magnetic fluid in which we use the electrometer instead of external load to directly measure the electromotive force of the test magnetic fluid in the tube is established to investigate the relationship of the variables of the test fluid and the performance of the power generation. Based on the setup proposed by Hiroshi Yamaguchi in Japan, we create an experimental set-up using a new idea. Furthermore, the electromotive force and internal resistance which the magnetic fluid in the tube generates decrease with the temperature, and the electromotive force increases with the velocity of the magnetic fluid, in other words, it increases with the Reynolds number, which is in good agree with the theoretical analysis. We have also showed the image of the electromotive force, velocity and the temperature, which has helped to develop the power generation.
Effect of Intermetallics on the Low Cyclic Fatigue Crack Growth Behavior of a Heavily Alloyed Al-Si Piston Alloy
Authors: Zhang Guo Hua , Li Bing Chao , Zhang Jian Xin , Feng Zeng Jian , Wei Zuo Shan , Cai Wei
Published: September 2012

This paper focuses on a typical automotive piston material to characterize its fractographic appearance after low cyclic fatigue test. The fatigue fracture of this heavily alloyed Al-Si alloy takes place in a brittle manner. The crack nucleated from a large intermetallic colony close to the specimen surface. When the crack encountered the intermetallics, it might progress along the interface among the intermetallics or the interface between the intermetallics and the eutectic. The debonded Al-Si eutectic region and intermetallics provided a weak material path for the crack propagation. A fatigue fracture mechanism in the heavily alloyed Al-Si alloy is elucidated.
Research on Key Technologies of Mesoscopic FEA Model for Polycrystalline Metal Power Spinning
Authors: Yang Bao Jian , Xia Qin Xiang , Xiao Gang Feng , Xie Hong Xi
Published: September 2012

Power spinning is one of the effective ways to refine grains of material and improve its mechanical properties. To explore the severe plastic deformation mechanism of power spinning for polycrystalline metal, the construction of mesoscopic plastic constitutive model and geometrical model was introduced in detail. A 3D representative volume element (RVE) of microstructure for polycrystalline materials was developed based on the finite element software ABAQUS by Matlab and Python script, and the parametric finite element gridding was realized with the LaGriT tool, which lays a solid foundation for the finite element simulation and prediction of microstructure evolution for power spinning of polycrystalline metal.
Influences of Process Parameters on Forming Performance of Sheet Metal Incremental Forming Based on Numerical Simulation
Authors: Li Jun Chao , Geng Pei , Pan Jun Jie
Published: September 2012

In order to investigate the process of ISF through numerical and experimental approaches, finite element method (FEM) models for two truncated pyramids were developed to simulate the process and the simulated thickness distributions were compared with experimental results. The influences of process parameters on equivalent plastic strain, the maximum equivalent plastic stress and forming force were also discussed. The results show that ISF process is basically to be a plane strain deformation. Wall angle is a more significant influence factor of forming performance than tool diameter and depth increment. With increasing tool diameter, decreasing wall angle and step increment, uniform thickness distribution will be achieved. However, more wall angel, less tool diameter and depth increment contributes to decrease forming force. Additionally, process parameters have no connection with work hardening for a certain material during ISF.
Electron Properties of F, and N Doped Hematite: The Application for Photocatalysis
Authors: Wen Xiao Hong , Pan Hai Jun
Published: September 2012

To improve photocatalytic activity of hematite, the electronic structures of F, and N doped hematite were studied via the first-principles band calculations with GGA+U methods. By analyzing the band structures of pure and doped hematite, we showed that the significant acceptor levels were induced by N dopants, whereas F dopants created shallow donor levels and Fermi energy entered the conduction bands. Our findings proposed that p-type dopant N was in favor of realizing the expectation of producing hydrogen in the visible-light photoelectrochemical (PEC) water splitting without voltage bias, and n-type dopant F was helpful to solve the problem of recombination of photo-produced electron-hole pairs The results of our calculation should be applicable to the improvement of photocatalytic performances of hematite.
Electrodeposition of Composite Coatings Containing AlN Particles in Nickel Deposit
Authors: Xia Fa Feng , Ma Chun Hua , Miao Liang
Published: September 2012

Nanometer Ni-AlN composite layers were prepared by electrodeposited technology. The optimum technological parameters of nanometer Ni-AlN composite layers were obtained by experiments and analysis. We observed surface morphology and metallurgical structure of composite layers with scanning electron microscope (SEM) and high respective transmission electron microscope (HRTEM). The test results showed that the nanometer Ni-AlN composite layers prepared by proper ultrasonic-electrodeposited technology have better wear resistance and corrosion resistance. And the composite layers consist of AlN particles and nickel grains both nanometer-sized.
Axial Buckling Behavior of Double-Wall Carbon Nanotubes by Finite Element Simulation
Authors: Chen Li Jie , Zhang Yi Fan , Zhao Qi
Published: September 2012

With finite element (FE) simulation, we study the buckling behavior of double-wall carbon nanotubes (DWCNTs) under axial compression. In the FE models, linear beam elements and nonlinear spring elements are used to simulate the complex structures and the Van der Waals' force between non-bond atoms from different layers is considered by the Lennard-Jones potential function. The effect of aspect ratio of DWCNTs and double-atoms vacancy on the buckling modes and the critical buckling strains are investigated. The computational results indicate that with the increase of aspect ratio, the critical buckling strains will decrease. For both armchair and zigzag DWCNTs, the critical buckling strains are generally larger than those of the single-wall carbon nanotubes with the same chirality as the external layers and those of the same structures without Van der Waals' force. For defective DWCNTs, the buckling strains of each order decrease by a maximum amplitude of 32.3%.
Effects of Sizing Removal by Air Heat-Treatment on Degradation of Silica Fibers
Authors: Qi Gong Jin
Published: September 2012

Sizing removal of silica fibers was carried out by air heat-treatment, and the mechanical strength, surface condition, microstructures were studied by tensile breaking force measurement, X-ray photoelectron spectroscopy, field emission scanning electron microscope and high-resolution transmission electron microscope. Heat-treatment at 600°C in air was suitable for sizing removal of silica fibers, with the residual strength ratio of 26.6%. The effects of sizing removal by air heat-treatment on the silica fibers are: (a) the sizing acts as an protective layer for the silica fibers to cover the surface defects and decrease the sensitivity under external forces, and the tensile strength drops a lot after the sizing removal; (b) the decomposition and combustion of the epoxy sizing also lead to the embrittlement of the silica fibers.
Numerical Simulation for Temperature of Ceramic Honeycomb Regenerator
Authors: Wang Yan Xia , Dong Min
Published: September 2012

Ceramic honeycomb regenerator as a critical component about the coalmine ventilation air methane thermal oxidation was proposed for a self-developed thermal reverse-flow reactor. A three-dimensional simulation model was established to obtain the distribution of temperature and velocity of gas, and the temperature variation of honeycomb at the length direction. The outlet temperature of gas variation with time was also obtained. The result could provide valuable reference for design calculation of the oxidizer unit and the later study of the thermal shock resistance.
Development and Application of Functionally Graded Material
Authors: Zhao Ning , Qiu Peng Yuan , Cao Lei Lei
Published: September 2012

Functionally graded material is a new kind of inhomogeneous material whose material properties change continuously with spatial positions. As a result of its excellent performance, it’s widely used in aerospace, nuclear engineering, biomedicine and some other fields that requirement of material is very strict. Classification based on different applications and research actuality are shown in this article.
Influence of Composite Antioxidants to Asphalt Anti-Aging Performance
Authors: Li Bian Hua , Liu Qi Cheng , Yu Yan Juan , Gong Du Ming
Published: September 2012

The durability of the asphalt is of great significance to its pavement performance, so more and more effort has been addressed on improving the asphalt anti-aging performance. In this work, the effects of antioxidant type and formula on the asphalt anti-aging performance were investigated through various measurements before and after aging process including needle penetration, softening point and ductility. Furthermore, the aging mechanism was analyzed via the FTIR (Fourier Transform Infrared) test. As a result, composite antioxidant can observably improve aging resistance of the asphalt. When the formula is 1.2%B+1.5%C+1.2%D, the needle penetration, ductility, softening point are as follows: 39.4×10-1mm, 148.1cm, 52.1°C. FTIR shows that carbonyl absorption peak reduced. Moreover, composite antioxidant can be more stable improvement of asphalt aging effect due to the cooperativity.
Experimental Study on Damping Properties of Fiber Reinforced Composites with Resin Matrices
Authors: Sun Shuang Shuang , Jiang Xian Ce , Ren Yong Sheng
Published: September 2012

The damping properties of glass and carbon fiber reinforced composites with epoxy and unsaturated polyester resin matrices were studied experimentally in this paper. It is found that temperature and frequency have significant effects on damping properties of these fiber reinforced resin composites. In the frequency range of 0Hz~30Hz, the damping factors of pure resin materials are higher than those of fiber reinforced resin composites. In the temperature range of -300C~500C, the epoxy resin composite shows the lower damping factors at about 200C, and the damping factors of unsaturated polyester resin composites keep increasing with the increase of temperature. Additionally, the storage modulus of the fiber reinforced resin composites decreases slowly with increasing temperature before the curing temperature is reached and it increases slowly with the increase of frequency.
Research Status of Natural Gas Hydrate in China
Authors: Chen Hai Feng , He Miao , Pan Yi , Yang Shuang Chun
Published: September 2012

The natural gas hydrate is a clean, efficient and abundant energy sources. Accordingly some countries give their attention to it and research by mint fund and manpower. However our country is late in this field. The researchers commenced their study in the end of 80’s, when they made vast pilot study such as investigation and data processing. With the support of our country, at the beginning of 90's natural gas hydrates was artificially synthesized for the first time, and at this century the mineral resources of natural gas hydrate was detected in the East China Sea and the South China Sea .At the same time the researchers made great research on the mechanism of formation, dynamic mechanism and formation conditions. However we are confronted with the problem of exploitation and the greenhouse urgently.
Effect of Inhomogeneous Structure of Polybenzoxazine on Mechanical and Thermal Properties
Authors: Xin Chun Ling , Li Gang , Yang Xiao Ping , He Ya Dong
Published: September 2012

Polybenzoxazine was one of the most widely employed matrix for advanced composites, due to their low viscosity, good dimensional stability, high glass transition temperature (Tg) and wide molecular design flexibility. To obtain high perfomance resin matrix, a fundamental understanding of the formation of crosslinking network structure and the relationship between structure and properties was essential. Therefore, the blends of benzoxazine precursor with different functionality were designed to achieve various network molecular architectures, and the effects of inhomogeneous structure of polybenzoxazine on mechanical and thermal properties were investigated. The bifunctional benzoxazine precursor (BA-a) based on bisphenol-A, formaldehyde and aniline, and the monofunctional benzoxazine monomer (Ph-a) based on phenol, formaldehyde and aniline were synthesized respectively. The blends of BA-a and Ph-a, in which the mole ratio was 1:0, 2:1, 1:1 and 1:2, repectively, were thermally cured through ring-opening reaction to obtain polybenzoxazines with various network structures. The fracture surface morphology of various polybenzoxazines was observed by atomic force microscopy (AFM). The hard phase with highly crosslinking density was dispersed in the soft phase with slightly crosslinking density, which led to the generation of inhomogeneous structure of polybenzoxazine. Dynamic mechanical thermal analysis (DMTA) of carbon fiber reinforced polybenzoxazine showed two glass transition temperatures (Tg), which corresponded to the soft phase and hard phase, respectively.With increasing the mole ratio of Ph-a, the increase of hard phase resulted in the enahncement of flexural modulus of polybenzoxazine, whereas the tensile and flexural strength of polybenzoxazine decreased due to the reduction of the crosslinking density of soft phase. Derivative thermogravimetric (DTG) analysis exhibited three major degradation steps, which characterized the decomposition, weight-loss and charring, respectively. Thermogravimetric analysis (TGA) showed that the onset degradation temperature and char yield at 850 oC increased with the increase of Ph-a mole ratio, indicating higher thermal stability and lower decomposition rate, which was attributed to the increase of hard phase with highly crosslinking density.
Coaxial Electrospinning with N, N-Dimethylacetamide for Preparing Methacrylate-Based Copolymer Nanofibers
Authors: Yu Deng Guang , Wang Xia , Zhang Wen Jing , Yang Hao , Li Ling Ling
Published: September 2012

A modified coaxial electrospinning process is developed for producing thinner methacrylate-based copolymer nanofibers. With Eudragit® L-100 (EL100) as a model and using a poor volatile solvent N, N-dimethylacetamide (DMAc) as sheath fluid, high quality EL100 nanofibers have been successfully generated using the developing coaxial process. SEM observations demonstrate that the nanofibers by the modified process have better quality than those produced by a single fluid electrospinning in terms of surface smoothness, nanofiber diameters and their distributions. The former has an average diameter of 240±30 nm while the later 490±170 nm. The mechanism is proposed that an appropriate DMAc surrounding to the core polymer jet helps to retain it in a fluid state to experience a longer time and more stable electrical drawing. The modified coaxial electrospinning process described here extends the capability of electrospinning process and opens a new way to obtain thinner polymer nanofibers with fine structural uniformity.