bluuebunny/crossref_metadata_2025 huggingface dataset:
Research of Ti/NanotubeTiO2/Sb-SnO2 Electorde and its Electrochemical Performance
Authors: Wang Yang , Zhang Jian Xin , Huang Amin , Wu Xiao Wen
Published: June 2013

In this paper nanotube TiO2 coating as an interlayer was produced on Ti substrate and the performances of the Ti/nanotube TiO2/Sb-SnO2 electrodes were investigated. It is shown that the microstructure of the nanotubes changes with the anodic oxidation voltage and time, and the introduction of the nanotube TiO2 in the electrodes gives rise to both the oxygen evolution potential and the accelerated life of the electrodes.
Analysis on Harmonic Characteristics of Electric Vehicle High-Frequency Charger
Authors: Zhou Yu Sheng , Pan Zheng , Zeng Long , Liu Yong Feng
Published: June 2013

As a nonlinear load, a large number of electric vehicle chargers inserted into power might bring many challenges, cause harmonic pollution to power grid. In this paper, a high-frequency charger is regarded as a researching object, the power characteristics of charger, harmonic current and impactive parameters are analyzed, and the harmonic analysis model of the charger accessed to power grid is built. Applying the Simulink and SimPowerSystems toolbox in Matlab and the simulation method facing the systems structure of electrical principle, the model is simulated. The harmonic generative rules and characteristics for a single high-frequency charger are present. The results might forecast the harmonic pollution of charge station, and provide the theory base for choosing harmonic control device and methods.
Transmission Scheme of MIMO Two-Way Relaying Systems Based on Symmetric Channel
Authors: Fan Jin Hong
Published: June 2013

There are fading and noise in MIMO two-way relaying system. A novel transmission scheme was proposed. The scheme performs equivalent to a 2×2 V-BLAST MIMO(Multiple-Input Multiple-Output) and a two 2×1 AlAMOUTI MISO(Multiple-Input Single-Output) in multiple-access phase and broadcast phase respectively. Network coding and minimum mean square error detection are employed at the relay. Binary phase shift keying and 8 phase shift keying modulation is used. The performance is analyzed under the assumption of a symmetric relay channel model. Simulation results show that the proposed transmission scheme can facilitate more reliable transmission.
Experimental Research on Factors Influencing Positioning Precision of Linear Electrohydraulic Servo Systems
Authors: Cristescu Corneliu , Drumea Petrin , Dumitrescu Catalin , Llie Ioana , Dutu Iulian
Published: June 2013

The article presents the results of conducting experimental research on factors influencing the positioning precision/error of linear electrohydraulic servomechanisms. Based on the mathematical model and preliminary experimental research conducted there have been identified factors that influence the positioning accuracy, and have been proposed some measures to control it in normal limits. The experimental results obtained highlight interesting aspects from the scientific point of view; they can be used to optimize the positioning precision of linear electrohydraulic servomechanisms.
Experimental Study of the Wheel Drive EV with External Rotor Switched Reluctance Motor
Authors: Gao Lian Xue , Sun Dian Sheng
Published: June 2013

Equiped with an electronic differential function in double wheel or four wheel electric vehicle drive, it must be driven by motor torque control precisely . Due to the nonlinear characteristics of the motor when the wheels switched reluctance motor drive, it is difficult to ensure motor torque and phase current relationship by the theoretical approach. This paper puts forward the experimental methods to get the different speed motor torque and given the relationship between the current , so as to make table, according to the rotation of the motor speed and torque requirements, the accurate switched reluctance motor torque control through given the current value in the future of the electric vehicle.
Conducted EMI Noise Prediction in DC Converter System for Electric Vehicle Application
Authors: An Zong Yu , Wang Quan Di , Zheng Ya Li
Published: June 2013

In this paper, common mode (CM) conducted perturbations are predicted and compared with experiments in a full-bridge transformer-isolated buck converter system, thanks to a complex approach based on experimental measurements and on the modeling of the complete equivalent circuit. Its different part are considered and represented by a circuit of lumped parameters. Simulation and experiment of CM emission in the conducted frequency range (150 kHz-30 MHz) are compared. It is shown that the CM emission in the system can be calculated by the proposed model, and experiment has successfully confirmed this approach.
Study on 3-Phase PWM Rectifier Controlled by Direct Power
Authors: Gong Xuan , Liu Di Chen , Dong Fei Fei , Wang Bo
Published: June 2013

Based on the analysis on shortcomings of controlling strategies of direct power on the traditional 3-phase Boost-type PWM Rectifier through space vectors, a new controlling strategy is proposed in this paper. With this new strategy, the space vector is divided into 12 basic space vectors to form a new switching table. The instantaneous power controlling technology is realized through the control of instantaneous active power and reactive power by choosing the best switching state of PWM Rectifier. This new controlling strategy can put the input side unit power into operation, improve the efficiency of power and reduce harmonics of the input current. The effectiveness and feasibility of this controlling strategy have been justified through the simulation and experiment.
Study Temperature and Humidity Influence on High-Power IGBT
Authors: Luo Bing Yang , Mo Yi Min , Zhang Wen Lu , Liu Si Ning
Published: June 2013

This paper has made a statistic survey on the failure rate of the appliance of high-power IGBT on the Harmonious locomotive. According to the analysis ,environmental temperature and humidity have a crucial influence on failure rate, thus a set of temperature and humidity monitoring system has been designed to investigate the environment temperature and humidity of high failure rate Four-quadrant IGBT modules, analyzing factors such as temperature and humidity and the working conditions accordingly, exploring the relationship of rising temperature of IGBT ,locomotive speed ,pressure of the air cylinder, setting a foundation for later analysis on the mechanism of troubles.
Analysis Remnant Life of Power Transformer Based on Health Index
Authors: Huang You Wei , Song Bin , Yuan Rong Xiang , Liu Hui Jin
Published: June 2013

According to the transformer testing information, the factors affecting of transformer remnant life assessment were analyzed. The formula which reflects the transformer health condition and remnant life is deduced and established according to the current information. The model thus is used in the health condition assessment and calculation of the remnant life for transformers. The results show that the process is consistent with the practical situation.
Simulation on Before-Arc Process of Large Current Breaking in Vacuum Circuit Breaker
Authors: Li Jing , Cao Yun Dong , Liu Xiao Ming , Yu Qiu Ting
Published: June 2013

Arc breaking at the function of large current is one of the bottlenecks for the development of vacuum breaker to higher voltage level. Simulation on arc is one of the most effective methods in this field. Before-arc process model of vacuum circuit breaker (VCB) whose breaking current is 20kA current and clearance is 10mm is developed here based on Boltzmann equation. Collisions between charged particles and metal vapor and electrodes are considered in the simulation. The physical nature of the sheathe and arc columns formation, the space charge densities and their effects on electric field strength before the steady state of arc plasma are simulated here.
Mechanical Properties of Concrete with Compound Mineral Admixtures
Authors: Li Yun Feng , Xu Zhi Feng , Wang Ling Ling
Published: June 2013

The influence of multi-component composite mineral admixtures on the mechanical properties and workability of concrete is studied in this paper, such as steel slag (SS), blast furnace slag (BFS) and fly ash (FA). Considering the above-mentioned factors, the optimal mixture ratio and substituted amount of composite mineral admixtures replacing equally cement are obtained. The results showed that composite mineral admixtures reduced the early compressive strength of concrete with composite admixtures, but significantly improved the workability and later compressive strength of concrete with composite admixtures. On the other hand, the optimal mixture ratio and substituted amount of double-mixing mineral admixtures are different.
Island Configuration for Service Restoration of the Smart Distribution System
Authors: Wang Xu Dong , Liang Wei
Published: June 2013

sland operation is a special operation mode for service restoration for the smart distribution system with distributed generation. In this paper, a model of island reconfiguration of the smart distribution system is proposed. The objection of this model is maximizing the total power supply profit. Meanwhile, load priority, controllable and uncontrollable load, and the restrictions of power balance, voltage and equipment capability are all taken into account. The island configuration problem is first simplified as a special knapsack problem, and based on the solution of this knapsack problem an initial island scheme is gained. By feasibility checking and adjusting, a island configuration is finally proposed. The results of the samples demonstrate that the model and method presented in this paper is feasible and valid.
The Analysis of Particle Swarm Optimization Used for Distribution Network Fault Location
Authors: Feng Gang , Zhou Jun , Liu Dan Li , Fan Kang Lin , Zhang Zhan Long , Guo Min Yi
Published: June 2013

In view of their own limitations of GA[1] and ACA[2][3] in the fault location of distribution network, this paper presents a new group intelligent optimization method which is simple and easy to implement, fast convergence rate, more global optimization ability, etc, and this is the PSO. Then the basic principles of the PSO algorithm and the Standard algorithm of PSO are discussed in details, on the base of that, this paper continues to introduce the principle of PSO algorithm which is used in the fault location of distribution network. This section mainly introduces the structure of distribution network, then makes a brief introduction of the fault location algorithm, finally writes out the detailed steps of PSO algorithm. When already understood the principles and algorithms, a detailed analysis of the distribution network. This paper makes use of this method in the process of the location of transformer combined with the high accuracy of fault location which avoid the possibility of local convergence. Finally this paper gives the analysis of case, the result shows that the proposed method of distribution network fault location is feasible.
The Impact of Electric Vehicle Charging Stations on Power Flow Calculation and Grid Loss
Authors: Sun Yu Tian , Zhang Hua Dong , Li Zhi Hui , Li Jian Xiang , Qi Cheng , Liu Zhi Zhen
Published: June 2013

Electric vehicle charging stations are high-power load after they are accessed to the grid. Therefore it may result in the redistribution of the grid load, which leads to the change of the power flow and the grid loss increases. The load model of charging stations is established in a typical distribution network model in this paper. The impact on the distribution network power flow after the electric vehicle charging stations accessed to the grid is calculated. And then some measures to reduce the network loss are brought up, which are proved by relational calculation cases.
Fault Line Selection in Distribution Networks Based on Parameter Identification in Frequency Domain
Authors: Suonan Jia Le , Li Zong Peng
Published: June 2013

The distribution network is mostly the ungrounded neutral system or the resonant grounded system in many countries. Selecting the fault line as soon as possible is of great significance to power systems. This paper proposes a parameter identification method in frequency domain to solve this problem. By using the matrix pencil method to extract frequency-points and their information in zero-sequence voltage and zero-sequence current, spectral leakage in DFT is avoided. With the estimated frequency points, an equation in frequency domain is established which will help to calculate the capacitance value and thus to identify the fault line. This method requires a low sampling rate and has high accuracy. In addition, the frequency-band in this new method is wider than the SFB's frequency-band. Verified by simulation in ATP-EMTP and data from RTDS, the new method is quite effective in fault line selection with an ability to overcome transition resistor and is immune from the impact of arc-suppression.
Voltage Track Prediction Based on WAMS
Authors: Miao Qian , Yan Feng , Liu Ya Nan
Published: June 2013

In order to give online voltage monitoring and stability margin judgment, a radial basis function (RBF) is used in this paper to predict the node voltage amplitude. Using BPA build IEEE9 network and input the processed data to RBF neural network, compared the results with the actual voltage amplitude, got a accurate prediction result. So as to stand out the accuracy of RBF, compared the relative error of prediction results between RBF and the second exponential smoothing model (SES). It testified the accuracy of RBF was more superior.
Research on Visual Design of Information Management System for Overhead Distribution Lines
Authors: Wang Yan Hai , Jiang Wei , Shi Cong Yong
Published: June 2013

Based on the characteristics of overhead distribution lines, according to the principles and methods of the 3ds Max software to create 3D model, this paper introduces how to solve the key issues for the visualization of the management system of overhead distribution lines. The process of the study shows that use 3ds Max turning, lofting and boolean functions, to draw 3D model of the overhead distribution line irregular shape parts is simple and feasible, make whole 3D model and video, can display a vivid of the various components of overhead distribution line. Enables managers to query data more intuitive, and provide a reference for management decision-making, research results can be applied in other electric power information management system design.
Simulation System Research on Live Working for 500kV Transmission Line
Authors: Yang Lian , Wang Bin , Li Xiao Feng , Hu Chuan
Published: June 2013

500kV EHV transmission networks have become the main one of the national grid, carring out live working for 500kV EHV transmission lines is the objective requirements to ensure the stable operation of the grid system. This paper uses a new system to simulate and analyse the way of entering the high electric area on 500kV transmission line. The system has built the ZM1 transmission tower and line model, accurately accounted the complex gap and satety distance. The simulation results show that the system can effectively get the best secure route and determine the way to enter into the equipotential with the safety margin.
Application of Smart Phone in Distribution Network Inspection and Troubleshooting
Authors: Xue Bao Xing , Zhu Feng , Guo Li , Li He
Published: June 2013

Distribution network has large number of facilities and very complex grid structure [. In order to improve the quality of maintenance, and shorten troubleshooting time in distribution network, this article proposes an inspection and troubleshooting support strategy based on smart phone [. Inspection and troubleshooting tasks can be dispatched directly to maintainers smart phone, and real time troubleshooting process can be reported to emergency command center. The application of smart phone can significantly improve daily inspection quality, shorten troubleshooting time. With the real time feedback from maintainers in working area, the whole troubleshooting process becomes standardized and transparent.
Applications in Medical Reagent Test Equipment of Semiconductor Refrigeration
Authors: Liu Jia , Xu Chang Gui , Xiang Hui Yu , Li Zhe , Niu Kai
Published: June 2013

In this paper, we use the knowledge of semiconductor refrigeration, developed a small temperature-constant box, which can meet the need of biological agents and storage conditions, and suitable for medical biological agents reaction experiment equipment line, to guarantee the reaction activity of biological agents in daily preserving and experimental. It can be embedded into test line, and has the advantages such as small size, high precision temperature control, easy to adjust, can two-way control temperature, no refrigerant, and no pollution-free. This paper introduces the design of the basic temperature-constant box structure, working principle, function realization and the actual realizing process. After inspection, the temperature-constant box produced for experiment can meet the requirements of the assembly line; its advantage is outstanding, suitable for the actual use of assembly line.
Fast Interrogation Method Based on Two Superimposed Fiber Bragg Gratings
Authors: Ma You Chun , Wang Chang Jang , Yang Yuan Hong , Li Jin Ming
Published: June 2013

A fast interrogation method based on two Superimposed Fiber Bragg Gratings (SI-FBGs) is researched. The two SI-FBGs under100Hz dynamic sinusoidal strain with linear triple driving voltage and 500Hz FFP-TF scanning frequency with 20nm wavelength range is simulated based on transfer matrix. A four times increase in the interrogation speed of dynamic strain, by generating a 2kHz optical sensing pulse train from a 500Hz scanning frequency, is demonstrated experimentally. The simulation and experimental results show that the interrogation speed can be increased by times with more SI-FBGs used.
A Simple and Effective Method of Temperature Calibration to Improve the Accuracy of Thermal Conductivity Instrument
Authors: Nie Qian Chao , Nie Qian Dong , Chen Hui Yi , Zheng Kai , Han Qiang
Published: June 2013

Errors in measurement of temperature have a significant negative impact on the thermal conductivity measurement. This paper analyses the causes of temperature error and why a small temperature error could often cause a huge error in thermal conductivity instrument. Since traditional methods often involve complex circuits or formulas, here we introduce a convenient and efficient method to improve temperature measurement accuracy, which by effectively combination of the table consulting and a new simple interpolation method introduced in this paper. It is implemented in the LabVIEW environment and experimental results show the accuracy of the instrument has been greatly improved.
The Error Analysis of a New PV Fault Diagnosis System
Authors: Cheng Ze , Xu Yong , Dong Meng Nan
Published: June 2013

The paper analyses the error factors of every part of the new pv fault diagnosis system which may affect the final diagnostic result and the fault positioning result. According to the different characteristics of each factor, we present the effective methods from the aspect of hardware or software to eliminate or reduce the errors, so the precision of the whole system can be improved.
Research and Development of Large-Scale Worm Gear Pair Tester Based on Time Grating Displacement Sensor
Authors: Zheng Yong , Chen Yan , Chen Zi Ran
Published: June 2013

With a good many advantages, the worm and gear has been widely used in mechanical equipment. To realize transmission error (TE) detection of worm gear pair is important for the comprehensive detection of large worm gear pair. The tester adopts time-grating displacement sensor as angle feedback sensor, and the multi-stage clock interpolation principle is applied for TE collection. In order to facilitate hardware system integrating and upgrading, the FPGA with NIOS II is used for realizing microcontroller.
An Electricity Parameter Measurement for Off-Grid PWM Converter
Authors: Chen Fang Yuan , Huang Jian
Published: June 2013

The input voltage of off-grid PWM converters has a great dynamic range in amplitude and frequency. In addition, the frequent changing of these parameters also makes it hard to measure preciously via traditional ways. Details of window function are presented. A modified FFT spectrum analyzing method using interpolation is also given and checked. Finally, a feasible solution which balances both precision and real-time data processing comes up considering the speed of MCUs mainly used in industry. Simulations and experiments show that this solution settles the troubles which cant be cleared up by traditional methods.
A Research on the Performance of Grey Chassis Organic Coating on Vehicle Equipment
Authors: Xu An Tao , Luo Bing , Zhang Fan , Zhang Tian Ru , Wang Ying
Published: June 2013

By adopting coating damage simulation method with electrochemical impedance spectroscopy, the influence of different damage degree K of grey chassis organic coating to its protective performance has been studied. The research found that electrochemical impedance spectroscopy could reflect the damage degree K of the coating. When K is less than or equal to 0.11, the coating still has prefect protective performance, when K is higher than or equal to 2.78, the protective performance of the coating is very low, and when K falls in between, the protective performance of the coating is just favorable; There exist a linear relationship between log (|Z|0.1Hz) and log K, which may provide a theoretical basis to evaluate the protective performance of such kind of coatings.
Optimization of Active Shimming for Magnetic Resonance Imaging Magnet
Authors: Guo Li Hui , Yang Wen Hui , You Xiao Fei , Wei Shu Feng
Published: June 2013

An iterative method of active shimming has been presented, which is based on the Laplaces Spherical Harmonics and the least square theory. This approach makes the inhomogeneity of magnetic field to acceptable restriction. With analysis of the method, this paper gives the computer-aided program. The simulation results approve that the method is feasible and valid. Because of its simple and easy to implements, this approach can also be used for the shimming of the other magnets such as the nuclear magnetic resonance magnets.
Design on Flow Measurement Solution with Intelligent Efflux Coefficient Standard Throttling Gear
Authors: Duan Quan Sheng , Zhao Qing , Wang Li Cui
Published: June 2013

t is an in-depth research on the span measurement range ratio that standard throttling gear measures the flow is too small, and proposes the design method of multi-efflux coefficient standard throttling gear. Expanding the lower limit of measurable flow according to the relevant national standards GB/T2624-2006. Solution divides the span measurement range into several segments, each piece span measurement range corresponds to a differential pressure gauge, and calculates corresponding efflux coefficient depending on the GB/T2624-2006 to get many outflow coefficients on the different span measurement sub-range section. Intelligent system chooses corresponding efflux coefficients based on different differential pressure, and ensures measurement accuracy at the same time of expanding the lower limit.
A Research on the Protective Performance of Green Organic Composite Coating on Vehicle Equipment
Authors: Xu An Tao , Luo Bing , Zhang Fan , Jin Fu , Liu Yang Yang
Published: June 2013

By adopting coating damage simulation research method with open circuit potential and electrochemical impedance spectroscopy, the influence of different damage levels of green organic composite coating to its protective performance has been studied. The research found that the variation of open circuit potential partly reflected the damage level of the coating. When K is less than or equal to 0.04, the coating still has favorable protective performance, while K is higher than 16, the protective performance of the coating is basically unavailable, but when K falls in between, the protective performance of the coating is fair good.
An Interface from LabVIEW to the Knock Sensor Testing System
Authors: Hu Qiao Peng , Feng Ze Kun , Xiao Xia , Gong Rong Zhou
Published: June 2013

This paper proposes how to use a domestic data acquisition card to develop a car knock sensor testing and analysis system, which is based on the U.S. NI LabVIEW. The content of the testing section is to design a driver based on the dynamic link library, aimed at making a communication between LabVIEW and the data acquisition card. This system can realize real-time acquisition for the knock sensor output signal, and the testing interface is simple and practical.
The Research for Rejecting the Redundant Data during Section Splicing Large-Aperture Aspheric Optical Elements
Authors: Zhang Dong Xu , Wang Zhen Zhong , Wang Zhan Shuai , Zhang Yan Ting , Li Xin , Pan Ri , Guo Yin Biao
Published: June 2013

The splicing measuring method applied in large-aperture aspheric surface optical elements, can extend the range of precision measuring instrument and expand measurement capability of the system. In this paper, two methods are proposed: the fitting evaluation method and the curvature comparison method in the light of how to reject the redundant data of the splicing coincidence part, and the theoretical analysis are investigated to calculate the theoretical error. The Talysurf PGI 1240 profilometer of Taylor Hobson Company is used as application object to do experimental research. The results show that the curvature comparison method is feasible and has characteristic such as fast speed, high precision, and good operability.
Research on the Electromagnetic Compatibility of Microcomputer Protection
Authors: Liu Min , Song Hua Wei , Zhao Jin Feng
Published: June 2013

This paper analyzed the main interference sources and their influences on the operation of protection both in the smart substation and the traditional substation. The interferences could be suppressed by reducing radiation of the interference sources, blocking the coupling channel of common-mode interference, promoting the anti-electromagnetic interference ability of the sensitive circuit and designing the bleeder circuit rationally. A microcomputer protection has passed the EMC test successfully by adopting these measures.
Detection of Flicker Caused by Interharmonics Based on the Voltage Envelope Mean FFT
Authors: Ren Zu Hua , Wang Bo Lin
Published: June 2013

This paper introduces a detection algorithm of flicker caused by interharmonics based on the voltage envelope extraction and analysis. Whether the interharmonic frequency is near the odd or the even harmonics, the envelopes show different characteristics. The envelope mean is calculated accordingly and the relationship between the envelope mean and the flicker signal is analyzed in detail. It concludes that the flicker frequency and amplitude can be obtained accurately through FFT of the envelope mean and amplitude correction. Simulation results verify the algorithm.
The Design of 13.56MHz RFID Reader Antenna
Authors: Zhang Hai Feng , Tong Yao
Published: June 2013

As the fast development of electronic technology, RFID technology is widely used all over the world. Firstly, the design about a kind of reader antenna was proposed with detailed analysis about theory and structure of the antenna circuit which relied on the 13.56MHz radio frequency integrated chip THM3060.Then a primarily introduction of circuits for radio frequency transmission and reception of reader is given. After that some important antenna parameters were determined that satisfied antenna matching circuit. Finally, experiments showed that the designed antenna is with good performance and reader can work stably.
A Novel Optimization Approach Based on Scratchpad Memory for Mobile LBS
Authors: Hu Rui Xin , Hu Wei , Zuo Ze Yu , Wang Min , Xu Jing , Lv Yi Ke
Published: June 2013

With the popularization of mobile broadband network, mobile devices have been used more wildly in recent years. As an important part of mobile services, LBS (Location Based Service) also has rapid development for such devices. However, LBS on mobile devices will consume more energy and mobile users have more restrict performance requirement than before. As an important part of on-chip memory, scratchpad memory (SPM) has less power-consumption and higher performance for SPM is controlled by software and without extra tags. In this paper, we proposed a novel optimization approach based SPM for mobile LBS to reduce the power-consumption and improve the performance of the application. According to our approach, SPM is used as the on-chip main memory to contain the data with high frequency of use. The experimental results show that SPM can optimize the mobile LBS both on power-consumption and performance.
Design of the Pulse Triggered by Three-Phrase Controlled Rectifier Circuit
Authors: Li Rui
Published: June 2013

Have designed the software and hardware formation of the six-pulse triggering device which is based on the all-controlled bridge type of Three-phase circuit of the single-chip microcomputer PIC16F877A . This new controllable silicon triggering system can show the triggering angle specifically and work steadily.
Assisted Optimization of the Servo Driving by Using Virtual Labview Instrumentation and the Elementary Transfer Functions and Neural Network Methods
Authors: Olaru Adrian , Olaru Serban , Oprean Aurel
Published: June 2013

In the optimisation stage of the systems one of the more important step is the optimisation of the dynamic behavior of all elements with priority the elements what have the slow frequency, like motors. The paper try to show how will be possible to optimise very easily the dynamic behavior of elements and systems, using LabVIEW propre instrumentation and the application of the transfer functions and neural tnetwork theory. By appling the virtual LabVIEW instrumentation is possible to choose on-line the optimal values for each constructive and functional parameters of the elements and the systems to obtain one good dynamic answer: maximal acceleration without vibration, minimum answer time and maximal precision. The paper presents some of the more important used transfer functions in the assisted analyse of the elements and systems and some practical results of the assisted optimisation by using the neural network method. In the research were been used some different way to optimize the convergence process, for example: using one time- delay of the first and second output from the neural layers; using the recursive link and time- delay; using the bipolar sigmoid hyperbolic tangent sensitive function replacing the sigmoid simple sensitive function. By on-line simulation of the neural network was possible to know what will be the influences of all network parameters like the input data, weight, biases matrix, sensitive functions, closed loops and time- delay, to the gradient errors, in a convergence process. In the optimization research we used the minimization of the gradient error function between the output and the target.
Mathematical Model for Studying the Evolution of Multi-Role Unmanned Aerial Vehicle in Turbulent Atmosphere
Authors: Mihailescu Cristina , Farcasan Ioan
Published: June 2013

The paper purpose is to present some aspects regarding the control system of unmanned aerial vehicle - UAV, used for local observations, surveillance and monitoring of interest area or as a training target for anti-aircraft systems. The calculus methodology allows a numerical simulation of UAV evolution in bad atmospheric conditions by using a nonlinear model, as well as a linear one for obtaining the guidance command. The UAV model which will be presented has six DOF (degrees of freedom), and an autonomous control system. This theoretical development allows us to build the stability matrix, command matrix and the control matrix and finally to analyze the stability of autonomous UAV flight. A robust guidance system, based on Kalman filter will be evaluated for different fly conditions and the results will be presented. The flight parameters and guidance will be analyzed. The paper is inspired by national project SAMO (Autonomous Aerial Monitoring System for Interest Areas of Great Endurance).
Keywords: UAV, Simulation, Control, Guidance, Endurance, Surveillance, Monitoring, Kalman filter
Modelling and Control of a Star-Shaped Octorotor
Authors: Adîr Victor G. , Stoica Adrian M. , Whidborne James F.
Published: June 2013

The quadrotor is starting to be considered a serious candidate for small and precise VTOL UAV missions. However, one important drawback is the insufficient payload capability. The current paper proposes the star-shaped octorotor as a solution. Its dynamic model is derived and a control mechanism for stabilization and trajectory tracking is designed and tested using numerical simulations. The approach proves to be feasible. Thus, the base for creating an autonomous octorotor UAV is established.
Simulation of Manipulator with Flexible Joint
Authors: Wang Hai , Xia Xiao Pin
Published: June 2013

Joint flexibility is the key factor during dynamic control of robot manipulator. Accurate dynamic model is the fundamental of manipulator system design, analysis and control. This paper adopts Lagrange method to accomplish two degrees freedom manipulator modeling, and then design Backstepping control law according to a single-link manipulator. For the above control law, the proof of the Lyapunov stability is given and simulations are done. The simulated result suggested that the static error is decreased.
Synthesis and Electrochemical Properties of Rechargeable Battery Electrolyte Lithium Bis(heptafluoroisopropyl)tetrafluorophosphate
Authors: Guo Ai Hong , Feng Shuang , Mi Yun Ting , Li Hong Zhi
Published: June 2013

Lithium-ion secondary cell has high energy density, stable and high working voltage, wide working temperature and long working term. It is a safe and clean energy resource without pollution. At present, Lithium Hexafluorophosphate is used as conducting electrolyte lithium salt in lithium-ion secondary batteries. But Lithium Hexafluorophosphate as conducting electrolyte lithium salt has some disadvantages such as hydrolysis and instability. Lithium Bis (heptafluoroisopropyl) t-etrafluorophosphate Li [(C3F7)2PF4] was received by simons process from diisopropylchlorophosphane in this paper. As electrolyte of Li ion secondary cell, Li [(C3F7)2PF4] had lower vapor pressure than LiPF6 in the solvent in the same temperature, comparable conductivity and oxidation stability in the same concentration in room temperature. It was worth mentioning that Li [(C3F7)2PF4] has excellent stability towards hydrolysis. The synthesis process is safe and easily controlled.
Research on Synthesis of Mullite Whiskers by Kyanite
Authors: Guo Ai Hong , Tian Li Nan , Niu Fu Sheng , Yin Li Jun
Published: June 2013

In this paper, thermal barrier materials of mullite whiskers made by kyanite is studied, take -325~+400 mesh kyanite as raw material, the firing conditions is that nucleation temperature is 1150°C and crystallization temperature is 1250°C; the adding method of catalyst (AlF3) is external additive. After the orthogonal experiment, it is determined that the effects order on products of raw material granularity, heating rate and catalyst addition is raw material granularity > catalyst addition > heating rate, and the best experimental conditions is obtained.
Research on the Microstructure and Tribological Properties of the Electroless Ni-P-PTFE Composite Repairing Coating on Gears
Authors: Jiang Nan , Fu Chuan Qi , Wang Zhou
Published: June 2013

The abrasion of axle parts would shorten their useful life, which could be significantly ameliorated to improve the wear resistance of gears through surface repairing and lower production cost. In this work, preparation technology of electroless Ni-P-PTFE composite repairing coatings on 45# carbon steel was investigated by the method of cerium induced codeposition. Coatings with PTFE ranging of 0-10g/L and Ce2+ of 0-1.0g/L were obtained. SEM and XRD were employed to study the worn surface topography, wear mechanism and microstructure of the coatings, respectively. The results indicate that the PTFE particles uniformly distributed throughout the Ni-P matrix, on the edge position of Ni-P crystal cells, and small amounts of which were wrapped in the crystal cells. The wear mechanism manifested as adhesion and slight grain-abrasion, along with associated ploughed grooves. It was also demonstrated that the wear rate of deposits is 2×10-6mm3.N-1.m-1 in condition of dry sliding, which is smaller than it by 3 orders of magnitude. Obviously, electroless Ni-P-PTFE coating improves the wear resistance of gears significantly and can be used as repairing coating.
Correlation between the Geometric Parameters of Corrosion Pit and Stress Concentration Factor
Authors: Zhao Wei , Huang Yong Fang , Ye Xu Bin , Hu Ben Run , Liu Jian Zhong , Chen Li Jie
Published: June 2013

Corrosion is one major damage mechanisms of aircraft structure, which can result in catastrophic failures and disasters. Quantitative analysis of pitting stress concentration effect is necessary for aircraft aluminum alloy structures, especially in coastal area. In the present paper, based on the observations of corrosion pit morphology of 2524 aluminum alloy using Keyence VHX-600 optical microscope and white light confocal microscope, three-dimensional finite element analyses (FEA) had been conducted systematically to evaluate the stress distribution of the cuboids aluminum alloy specimen with pits stressed remotely under uniaxial tension. It is found that pit metric parameter a/2c is the key parameter affecting stress concentration factor (SCF) and an empirical quantitative relation is given. In addition, we study the contribution of secondary (premature) pits at the bottom of hemi-spherical pit to the SCF of primary pit and an estimation formula is given. These provide significant methods for characterizing pitting damage and quantitatively estimating SCF so as to predict life.
Research on Application of Phase Change Materials in the Field of Building Energy-Saving
Authors: He Chang Quan
Published: June 2013

Purposes:Understand the category and application of phase change materials, and improve the effect of building energy-saving. Methods:Comparative analysis category,advantages and disadvantages, application scope and application value of phase change material in the field of building energy-saving. Conclusions:Phase change materials have important economic, environmental and social benefits in the field of building energy conservation, should strengthen the research, development and promotion on them.
Study on Energy Materials with the Impact of Using Chilled Water Storage Systems on the Performance of Air Cooled Chillers
Authors: Li Jie , Luo Yong Qian
Published: June 2013

In the air conditioning (AC) industry chilled water storage (CWS) systems are one form of cool thermal storage technology that can be used to time shift the electrical load of the system from the peak day periods to off peak night time periods. In this paper the data for the actual exported and generated electrical energy obtained for the power stations has been used to estimate the electrical energy consumption and the peak electrical load of AC systems. It is estimated AC systems represent about 62% of the peak electrical load. The results demonstrate that CWS can reduce the peak electrical load of a chiller in an air cooled AC system by up to 100% and reduce the nominal chiller size by up to 33% depending up on the operating strategy adopted. This is achieved with only a 4% increase in power consumption of the chiller for all CWS strategies except for full storage where the energy consumption actually decreases by approximately 4%.
Study on the Application of Fluorgypsum Plaster
Authors: Pan Hong , Li Guo Zhong
Published: June 2013

Physical modification and chemical activation were used to stimulate the fluorgypsum activity effectively. A compound activator was independently developed to increase its hydration activity, which can accelerate the hydration and hardening of fluorgypsum, so that the strength of the hardened body could be improved. Besides, appropriate water-retaining agent, water reducer and composite waterproofing agent were used to improve the comprehensive performance of fluorgypsum plaster, which gave it the value of engineering applications, and the production process route of fluorgypsum plaster was designed. All the performances of fluorgypsum plaster produced in this technology meet the standard requirements, which comply with the requirements of the economy, environmental protection and waste utilization.
Preparation and Study on the Properties of Gypsum Whiskers Reinforced Resin Matrix Composites
Authors: Du Chuan Wei , Li Guo Zhong
Published: June 2013

In this paper, gypsum whiskers reinforced resin matrix composites were prepared with the desulfurization gypsum by the technology of atmospheric acidification. The influences of stabilization reagent on the stability of the gypsum whiskers were studied. Meanwhile, the enhanced effects of surface treatment and different contents of gypsum whiskers on the resin matrix composite were analyzed. Scanning electron microscopy, metallographic microscopy, X-ray diffraction test were taken to conduct analysis of the morphology and the aspect ratio of gypsum whiskers. Besides, the mechanical properties of gypsum whiskers reinforced resin matrix composites were tested, and cross-section scanning was used to analyze the strengthening mechanism.
Hydromechanics Research of Pump Flow Control System Based on BP Neural Network PID
Authors: Zhao Xue Song , Hu Jian , Shi Pei Cheng
Published: June 2013

In order to improve the accuracy of the pump flow control system,With the application of hydromechanics:the actual flow of the pump is restricted by head,the mathematical model of the fluid flow control system is established.Through the analysis, which obtained three kinds of unit step response curve of the pump flow control when it is under the condition that without using the PID,using the PID and using the BP neural network combined with the PID control. It is concluded that the efficiency of using the BP neural network combined with the PID is much better, Which can improve the pump flow control system's accuracy.
Study of Interfacial Stiffness by Using the Structural Interface Model Based on Elastic Mechanics
Authors: Xie Zhi Min , Chai Dong Liang , Weng Yan Yan , Chen Si Chi
Published: June 2013

The recently proposed structural interface model is a realistic model of thick interfaces, but the bars of the structure are assumed iso-stiffness. In the present work, the structural interface consisting of pairs of bars with different stiffness is developed. Based on the neutral inclusion concept and elastic mechanics, the stiffness of bars of the structural interface is studied. It is found that all the bars have the same stiffness in a special loading condition of equal-biaxial tension. The finite element simulations for glass fiber-reinforced epoxy composite reveal that the fiber does not alter the prescribed stress due to the presence of the structural interface. Compared with the iso-stiffness-bar interface, the developed structure interface is more suitable for characterizing a multi-component interface and more flexible to be designed.
Helicopter Aerodynamic Parameter Identification via Flight Dynamics
Authors: Yu Xue Mei , Zhao An Ping , Li Xue
Published: June 2013

A method which can process flight test data by integrating parameter identification and non-dimensional flight dynamic model was proposed to acquire the effective aerodynamic parameters of a helicopter. First of all, a non-dimensional mathematic model considering flight dynamics was deduced for a helicopter in state of level flight, and some important parameters including aerodynamic and correctional were developed. Next, taking helicopter Z-9× for example, the least squares method was adopted to identify these parameters based actual flight test data. Lastly, the identification method was proved valid through feasibility analysis. Results show that this method is a good way to acquire aerodynamic parameters and can shorten flight test periods as well.
Vibration Analysis of Aeroengine Turbine Blade-Disc Coupling System
Authors: Zhao Wei Qiang , Liu Yong Xian
Published: June 2013

This paper introduces the FEA method for cyclic symmetric structures and makes an vibration characteristics analysis to a certain type of aeroengine turbine blade-disc coupling system based on this method. According to the analysis results, the dynamic characteristics of the blade-disc coupling system are discussed. The analysis method and results in this paper can be used for further study on optimal design and vibration safety verification for the turbine blade-disc coupling system.
Longitudinal Aerodynamic Modeling Based on Support Vector Machine
Authors: Gan Xu Sheng , Duanmu Jing Shun , Gao Jian Guo
Published: June 2013

In order to accurately depict the longitudinal aerodynamic characteristics of flight vehicle, a new aerodynamic modeling method based on Support Vector Machine (SVM) is proposed. SVM is a machine learning method that solves the problem by mean of optimization method on the basis of statistics learning theory, and introduces the structural risk minimization to coordinate the relationship between fitting degree and generalization ability, and the training samples are mapped into high dimensional feature space for linear regression, which can solve the practical problems such as nonlinearity, high dimension, over-learning, local minima, curse of dimensionality and so on. The experimental result shows that the method has a good modeling accuracy and speed training, and also is easy to implement. It is fully competent for longitudinal aerodynamic modeling for flight vehicle.
Modeling Tension-Compression Asymmetry of Shape Memory Alloys Based on Finite Elastoplasticity Model
Authors: Wang Xiao Ming , Xiao Heng
Published: June 2013

A combined hardening J2-flow elastoplasticity model is proposed to model tension-compression asymmetry of shape memory alloys in a direct sense. Results show excellent accord with test data for realistic pseudo-elastic behavior.
Study on Electrical Materials with the Circulation Control of STATCOM Based on MMC
Authors: Xie Yan , Li Su Fen , Mao Zhe
Published: June 2013

This paper introduced a new modular multi-level converter (MMC), which could enhance the voltage and power level by sub-converter modules in series and was easy to extend to any level of output. Its structure and working mechanism were described. By analyzing the higher harmonic components circulation generated by the inconsistencies in the three-phase upper and lower arm voltage, a loop control strategy is proposed for the suppression of the circulation in the arms of the M-STATCOM. Simulation results verify the effect of the controller.
Study on Photochromic Perfluorocyclopetene Containing Six-Numbered Unit as Optical Recording Materials
Authors: Wang Hai Bo , Fan Cong Bin , Liu Gang
Published: June 2013

A reversible molecule switching of symmetrical photochromic diarylethene 1,2-bis methyl phenyl perfluorocyclopentene has been synthesized and its photochromic and simulated molecule structure were also investigated. The compound exhibited photochromism both in solution and PMMA film but no photochromism in solid state. In hexane, the open-ring isomer of the diarylethene1oshowing an absorption peak at 308 nm. Upon irradiation with 313 nm light, a new absorption band in the visible region centered at 595 nm emerged to form closed isomer1c. This compound can be used as optical recording materials.