bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing of Sonar Image Based on Compressive Sensing
Authors: Xu Zhi Jing , Dai Huan Lei , Cao Pei Pei
Published: August 2011

The particularity of the underwater acoustic channel has put forward a higher request for collection and efficient transmission of the underwater image. In this paper, based on the characteristics of sonar image, wavelet transform is used to sparse decompose the image, and selecting Gaussian random matrix as the observation matrix and using the orthogonal matching pursuit (OMP) algorithm to reconstruct the image. The experimental result shows that the quality of the reconstruction image and PSNR have gained great ascension compared to the traditional compression and processing of image based on the wavelet transform while they have the same measurement numbers in the coding portion. It provides a convenient for the sonar image’s underwater transmission.
Material Classification Using Random Forest
Authors: Zhao Zi Ming , Li Cui Hua , Shi Hua , Zou Quan
Published: August 2011

Random forest has demonstrated excellent performance to deal with many problems of computer vision, such as image classification and keypoint recognition. This paper proposes an approach to classify materials, which combines random forest with MR8 filter bank. Firstly, we employ MR8 filter bank to filter the texture image. These filter responses are taken as texture feature. Secondly, Random forest grows on sub-window patches which are randomly extracted from these filter responses, then we use this trained forest to classify a given image (under unknown viewpoint and illumination) into texture classes. We carry out experiments on Columbia-Utrecht database. The experimental results show that our method successfully solves plain texture classification problem with high computational efficiency.
An Improved Blind Multiuser Detector Algorithm Based on Subspace Tracking
Authors: Hou Zhi Song , Yu Zhou , Zuo Xian Gang , Zheng Wei
Published: August 2011

Adaptive OPAST algorithm can ensure the orthogonality of weighted matrix in every iterations, and accelerate the convergence rate, improve the performance of error stably. However, it also enhance the complexity of algorithm. In this paper, an improved OPAST algorithm is proposed. The algorithm reduce cumulative error in the process of every iterations by inducting the dual Gram-Schmidt orthogonalization, ensure the algorithm has a better stability. Simulation results show this algorithm has stability convergence.
Research and Development the Method of Transformer Winding Deformation Fault Diagnosis Based on FRA
Authors: Qian Su Xiang , Li Zhu Ping , Gu Xiao Jun , Du Qi
Published: August 2011

For the purpose of enhance the accuracy and sensitivity of FRA of transformer winding deformation fault diagnose, this paper made several improvements on the traditional FRA. Regarding the signal source's insufficiency, we changed the impulse replaces the sine frequency sweep signal. The test results showed: after the improvement, the test cycle reduces and the signal frequency response range is broader. We also used the FFT and EMD method to improvement the analysis of frequency response curves, this increased the analysis accuracy and diagnose sensitivity, find the fault characteristic. This study can be used on the development of transformer winding fault diagnosis, detection and test methods.
Real-Time Detection of the Repose Angle of Solids in Rotating Drum Based on Image Processing
Authors: Liu Xiao Yan , Zhang Yao Yao
Published: August 2011

Rotating drum is the main part of industrial rotary kilns. The repose angle is one of the most important parameters describing the solids motion inside the drum. A real-time monitoring system is developed in this paper to detect the repose angle based on image processing techniques. The video of the solids motion is taken by a camera and transferred to a computer via an image-sampling box. With a VC++ program, the image of the solids is captured and processed through segmentation, morphology processing and edge detection. The repose angle is determined by linear fitting of the surface profile of the solids bed. With the image processing system, the dynamic change of repose angle with time can be measured and displayed automatically. The effectiveness of the measuring method is proved on a testing drum of 250mm partially filled with rice particles. Results of the present work can be expanded to the automatic monitoring of solids motion in industrial rotary kilns.
Analogy Analysis about Shape Coefficient of the Abnormal Roofing Structure with the Standard
Authors: Gao Liang , Bai Hua , Min Rui , Li Jia Wu
Published: August 2011

Based on the wind tunnel test of a mass culture activity center, the influence of the shape change of the structure with abnormal roofing on the wind loads shape coefficient were studied. The result from the test was compared with the values from the related items in the《load code for the design of building structure》[1]. Research results shows: the shape coefficient of the abnormal roofing structure is unfavorable to take norms similar structure shape coefficient values, need to measure it through wind tunnel tests.
Model Research on the Evaluation of Traffic Sustainable Development
Authors: Luo Yong , Guo Xiu Chun
Published: August 2011

By research, we can realize definitely the relationship between the urban transportation system mode and containable development; meanwhile, it suggests the evaluation methods evaluation contents and guideline of Large-sized and middle-sized civic traffic problems. According to the civic traffic containable development basic theory, the major action factors of the civic traffic containable development and the establishment of the civic traffic containable development evaluation guideline system. Afterwards, this paper takes main factors and weight to use the found evaluation system.
Western Region County-Level Highway Fuzzy Comprehensive Evaluation Research
Authors: Luo Yong , Guo Xiu Chun
Published: August 2011

With the development of the transportation, the county-country highway network has the more and more important function in the transportation network. Therefore, it is necessary to establish the scientific method evaluating the total function of the county country road network, so as to support decision for the synthetically transportation planning and management. The paper evaluates the whole construction level, layout quality and total capacity of the county-country highway network from the standpoint of holistic planning and synthetically transportation development. The status of the existent network is investigated and analyzed. Then the corresponding evaluating guideline system and method is put forward. Applying the proposed system and method, the paper analyzes the performance of some county highway network in Nanchong city and brings forward some improvement suggestions.
A Method to Improve the Accuracy of Adjustable Phase Difference of Signal Generator
Authors: Guo Jian , Liu Bing Wu , Dong Ping Ping
Published: August 2011

Direct digital frequency synthesis (DDFS) technology is applied widely in traditional fields which need signal source since it has a lot of advantages such as high frequency resolution, fast frequency setting and conversion speed and so on. Based on the working principle of DDFS, it is very important to calculate the phase control word when synthesizing the continuous adjustable phase difference signals. To address the shortcoming of large computation, low efficiency of phase difference setting, more storage space occupied or significant cumulative errors of phase setting when calculating phase control word with traditional methods, a novel algorithm for computing phase control word is studied in this paper. This new method does not need large computation and more space and simultaneously it can decrease the error greatly, which plays an important role in improving the phase setting speed and precision in signal generator.
Research on Corrugated Diaphragm Sensing Technique Detecting the Pressure outside the Casing
Authors: He Jun , Dong Hui Juan , Pan Hong Liang , Cheng Guo Juan , Xing Yang
Published: August 2011

Monitoring the pressure outside casing of oil-water wells is significant to prevent and reduce casing damage. Aiming at the problem of permanently monitoring the pressure outside casing of oil-water wells, according to FBG sensing principles, FBG is packaged by FRP, pressure sensitivity program is designed, make sure strain for four bending points of FBG sensor are well-distributed, take sinusoidal corrugated diaphragm as elastic element, a monitoring sensor with temperature compensation is developed. Pressure performance calibration test of the sensor is conducted, experimental results show that the sensor has stable performance and fine temperature compensation capability, the pressure measuring range is, sensitivity is 109.
Determination of Surface Acoustic Admittances by Inverse Solution of Finite Element Modeling in the Pipes
Authors: Yin Ye An , Horoshenkov Kirill , Ou Gui Bing
Published: August 2011

This paper presents an approach to determination of acoustic admittances by solving inverse problem which is obtained from finite element modeling. The authors detail the inverse problem and its general eigen-function and introduce an optimization method to obtain boundary conditions by known geometries in a discrete domain and the lowest propagating frequencies and their corresponding attenuations. This method is practical because it only needs few eigen value information rather than full information of the eigen values. Comparison of acoustic experimental results and calculated results, which match well, is given to validate the method.
The Propagation Properties of the Vector Dark Soliton
Authors: Wang Jin Li , He Ke Rong , Hu Jian Feng
Published: August 2011

The variational method has been used to study the interaction between the two polarized components of the vector dark soliton in a birefringent fibre. The interaction energy and force between the two components of the soliton have been derived, and then the propagation properties have been discussed in detail.
Microwave Power Real-Time Soft-Measuring Based on Improved BP Neural Network
Authors: Lei Lin , Ouyang Zhi Xiong
Published: August 2011

There are many faults in microwave power measurement in the working spots. In this paper, the novel technique of microwave power measurement and Schottky detector and the technique of soft-measuring based on improved BP neural network are presented. Making use of directional coupler, the part of power of microwave signal in transmission line was taken in the certain proportion. Then, the microwave power meter indicated the magnitude of power. The microwave power measurement system was composed of tuneable attenuator, directional coupler, matching load, peak-peak value detector, oscillograph, thermocouple, soft-measuring algorithm and so on. The low microwave power meter obtained the sample data of training BP neuron network. Then, the output of trained BP neural network may represent the result of high microwave power measurement. The experiments and applications in practice project prove that this new method has many advantages.
The High-Speed Ultrasonic Testing Method for Steel Pipes Based on Linear Reciprocating Probes
Authors: Kang Yi Hua , Tu Jun , Wu Jian Bo , Sun Yan Hua
Published: August 2011

This paper presents the high-speed ultrasonic testing methods for steel pipes currently, and points the existing difficulties, such as the instability in signal transmission, the problem of water coupling, and so on. Then the inspection method based on linear reciprocating probes is proposed to achieve the purpose of fewer probes and higher detecting speed. The mathematics model which adopts the slider-crank mechanism to realize the probes swinging fast in line is established as there is blind spot between the adjacent probes in high-speed inspection. With the help of simulation of Matlab, the relation curve between the rotation speed of crank and the rotation angle of crank is acquired, as well as the line speed of the steel pipe and the rotation angle of crank. The experiment platform is set up according to the simulation data, and the results verify the feasibility of the method.
Experimental Research on Transition and Flow Separation of Laminar Airfoil
Authors: Jiao Yu Qin , Lu Yan , Xiao Chun Sheng
Published: August 2011

Experimental research on transition and flow separation of laminar airfoil and the influence of transition and flow separation on the performance of laminar airfoil are carried through. The experimental device and instruments used in the research are introduced. It is shown from the experimental results that at certain scope of attack angle, flow transition shifts from 50%c to 30%c on the upper surface of airfoil model along with 1 degree increase of airfoil attack angle; For flow speed of 35m/s and 50m/s with attack angle from 4 degree to 8 degree, flow separation position don’t vary but only separation scope increase; For flow speed of 15m/s laminar flow separation on the upper surface of airfoil take place at attack angle of 4 degree, flow become attaching at attack angle of 6 degree and turbulent flow separation take place at attack angle of 8 degree.
Measurement of Flame Height by Image Processing Method
Authors: Zheng Li Gang , Yu Ming Gao , Yu Shui Jun , Lu Chang
Published: August 2011

In order to measure the flame height (Lf), the image processing method was employed. The jet flame image was captured by the common-used digital camera. The resolution (C, with the unit of mm/pixel) of the pixel of the digital camera was calibrated by metric scale. The jet flame image was then successively processed by ROI (region of interest) processing, gray processing, binarization and edge detection. Through the image processing, the pixels where the flame root and the flame tip were located was detected. The flame region expressed in pixels can be easily obtained by the difference between the flame root (X1) and the flame tip(X2). The flame height (Lf) was calculated by multiplying the difference in pixels (Lp= X2-X1) with the resolution of pixel (in millimetres per pixel). Using the proposed method, the flame heights of the pulverized coal jet flame at the high temperature air combustion condition were measured. The effect of experimental parameters on the flame heights of the coal jet flame was discussed.
Model Updating of Full Prestressed Concrete Beam Based on Bayesian Theory
Authors: Fang C.Y. , Zhang Yao Ting
Published: August 2011

Model updating based on Bayesian theory for the prediction of natural frequencies of full prestressed concrete beam has been developed. Morris screening method is employed to study the sensitivity of model parameters and elastic modulus and density of concrete are determined to be updated. Cooperative work between finite element analysis program and Markov chain generating program is realized, and multiple chains with different starting points are designed to obtain the posterior distribution of model parameters. It is found that standard deviations of posterior estimates decrease compared to those of prior distributions. In addition, different starting points are selected to discuss their influence on posterior estimates of model parameters. On reducing the uncertainty of posterior estimate, the difference of each natural frequency used as witness resource is compared.
The Application of CAD/CAE Integration Simulation Technology in Dynamic Analysis for Bearing
Authors: Zhou Biao , Deng Xiao Lei
Published: August 2011

The CAD/CAE integration simulation technology route of bearing is established, and the parameterization numerical model of 7021 angle contact ball bearing is established by using the Solidworks software. Then the finite element analysis of bearing assembly is carried out in ANSYS software. The simulation result indicates that the bearing structural design is reasonable, and the intensity request and the dynamic stiffness of the spindle system can be satisfied. By the analysis and simulation results, the process measures which can improve the structure and increase rigidity of bearing can be proposed．
Shear Stress Analysis of Long-Span Steel Bridge Deck Asphalt Pavement Using FEM
Authors: Hu Chun Hua , Qian Jin
Published: August 2011

Asphalt pavements have been widely used to protect the steel bridge deck against moisture and provide good riding quality. However, various types of distresses especially rutting have been observed frequently in bridge deck asphalt layers. Therefore it is necessary to understand the mechanics behavior of asphalt layer in the steel bridge deck. In this paper, finite element model for bridge deck with asphalt layers have been setup. Then shear stresses have been analyzed in the various cases using finite element method. The results show that the most disadvantage position locates above the diaphragm plate outer side. The shear stress between layers decreases with the increase of the asphalt layer thickness, the peak shear stress increases either. The thin surface layer has its advantage with the requirement of the minimum paving thickness if bonding properly. Comparison with the common pavement structure, the maximum shear stress in the bridge deck pavement could be affected by the type of loading more significant.
Effect of Treatments of Microwave Radiation and Steaming on Color of Larch Wood
Authors: Jiang Tao , Zhou Zhi Fang , Wang Qing Wen
Published: August 2011

Larch wood (larix) contains plenty of resin and a combined treatment with microwave irradiation and subsequently steaming is a strategy to remove the resins in the larch wood. In this study, the effects of microwave power (5.54, 12.92, and 24 kW) and steaming period (2, 4, 6, 8, 12, and 16 h) on surface color were investigated. After air-drying, L*（Lightness）, Ag*(Hue Angle), and ΔE*( color difference) values of control increased, however, redness（a*）, yellowness（b*） and Chroma（C*）values decreased. The color parameters of larch wood after microwave treatment and air-drying exhibited a same trend as the control, but the values were slightly larger than the absolute value of control. Simultaneous, L* and ΔE* values also increased but b* and C* values decreased. Most a* values decreased, Ag* values decreased or unchanged. Treatment with microwave-steaming followed with air-drying caused an increase in L* and ΔE*; however, b* and C* values decreased. Steaming for 8h and 12h at 12.92kW resulted in increased a* values but the other parameters decreased. For steaming The Ag* values did not exhibit any trend due to steaming.
The Effect of Varying Degrees of Radial Meniscal Tears on the Knee Contact Stresses: A Finite Element Analysis
Authors: Dong Yue Fu , Dong Ying Hai , Xu Qing Rong , Hu Guang Hong , Dong Wan Peng
Published: August 2011

Knee osteoarthritis (OA) is believed to result from high levels of the contact stresses on the cartilages and menisci after radial meniscal tears but not clearly proved. This research investigated the effect of varying degrees of radial meniscal tears on the peak compressive and shear stresses in the knee joint. An elaborate three-dimensional (3D) knee finite element (FE) model was developed from CT (computerized tomography) and MRI (magnetic resonance imaging) images. This model was used to model varying degrees of radial meniscal tears (involving 0%-90% radial width of the medial meniscus). Two different conditions were compared: a healthy knee joint and a knee joint with meniscal tears. The peak compressive and shear stresses were found in the posterior region of the medial meniscus and the corresponding zone of the cartilage, and they increased with the increasing width of radial tears. After meniscal tear involving 90% radial width, the peak compressive and shear stresses got their highest values. It shows that meniscal tear greater than 40% radial width drastically increases the contact stresses in the knee joint.
First-Principles Study of Nb Doping Effect on the Diffusion of Oxygen Atom in γ-TiAl
Authors: Zhao Chun Ying , Wang Xu , Wang Fu He
Published: August 2011

The effect of Nb doping on the diffusion of oxygen in γ-TiAl is studied by the use of first-principles. Our calculated results showed that the diffusion barriers of oxygen in γ-TiAl are increased by the Nb doping. And the effect of Nb doping dies down as the distance between the oxygen atom and doped Nb atom increases. Accordingly, the improvement of the poor oxidation resistance of γ-TiAl by Nb doping may be caused by suppressing the diffusion of oxygen atom in γ-TiAl.
Ablation Properties Experiments of C/SiC Throat-Insert in Operational Environment of Rocket Engine
Authors: Wei Xiang Geng , Li Jiang , Chen Jian , Dong Hao
Published: August 2011

The ablative performance of the C/SiC ceramic matrix composite material is studied experimentally using a experimental system based on solid rocket motor and liquid rocket engine in this paper. It is mainly studied how the ablative performance is influenced by ablation time, particle and temperature. It is indicated that the ablative performance decays with longer ablation time. The ablation becomes acute when the temperature is higher than 2973K, and the higher temperature, the more significant ablation. In addition, a large amount of vapor increases the thermochemical ablation of the material.
Influence of Heat Treatment Temperatures on Properties of Unburned Al2O3-C Slide Plate
Authors: Ma Xue Gang , Cui Zhi Min , Li Yuan Liang , Chen Ying , Wang Dong
Published: August 2011

Unburned Al2O3 - C slide plate specimens were prepared at different temperatures, using tabular corundum, graphite, Al, Si powder as starting materials and silicone resin as binder. The results reveal that heat treatment temperatures have a significant impact on the performance of unburned Al2O3 - C slide plate. Between 200°C and 600 °C, the internal structure of the specimens is loose, and the apparent porosity increases significantly, meanwhile the cold crushing strength is very low. Between 800 oC and 1000 °C, the bulk density increases significantly, the apparent porosity have a sharp decline, and the cold crushing strength value increases. Over 1000 °C, there are many holes in the specimens, specimen mass and thermal expansion significantly increases, the bulk density decreases, and the apparent porosity increases, in the same time, the cold crushing strength has a downward trend.
Improvements on the Sieve Plate Structure of Movable Sieve Jig
Authors: Wang Bin
Published: August 2011

Movable sieve jig has the characteristics of simple structure, low water consumption, large capacity, less infrastructure investment, and low production costs, which can replace manual rock picking and be used by many coal preparation plants. Due to the size and the shape of sieve pore, common sieve plate is easy to plug and has a short life with many materials leaking through the sieve, which leads to complex follow-up treatment process. Based on the analysis of coal preparation features, this paper proposes a structure of circular-wave sieve plate and conducts theoretical and experimental studies about that. The results show that the optimized circular-wave sieve plate can significantly improve the performance. Therefore, it is worth to be promoted in the industry.
The Preparation of TiO2 Nanoparticles and Wastewater in Paper Mill Treatment with TiO2 Nanoparticles
Authors: Zhu Yan , Yuan Shuai , Lu Tao , Meng Hao
Published: August 2011

Nano titanium dioxide particles were synthesized by drolysis of TiCl4 through the phase thransfer and pH of the system is adjusted by Na2CO3 At the same time, the particles were characterized by the Transmission Electronic Microscope(TEM) and X-Ray Diffraction(XRD).As the result, it is shown that the TiCl4 solution was transformed from n-octyl alcohol to deionized water phase and reacted with the deionized water at 55°C, the precursors of nano-TiO2—Ti(OH)4 was dried for 6 hours under vacuum at 70°C,then calcined 3 hours in muffle furnace at 400°C.At last, the TiO2 nanoparticles which is uniform distribution, weak agglomeration was synthesized. In addition, wastewater in paper mill treatment with TiO2 nanoparticles was studied by experiment. It is shown that suspended substance and COD in wastewater were brought dwon largely. The mechenism that wastewater was treated is disscussed.
Application of Improved BP Neural Network Model in Uplift Pressure Monitoring
Authors: Mei Yi Tao , Zheng Dong Jian , Xu Lei
Published: August 2011

The network structure, initial weights and initial thresholds were optimized to solve some problems, such as over-fitting and slow convergence rate in standard BP Neural Network. Combining the base seepage character of concrete dam, a uplift pressure monitoring model is established in this paper with measured data of a actual concrete dam . The advantage of the presented model is tested and validated by actual examples. It has positive significance in the actual application.
Nanoscale Trap for Isolated Cold Atoms by the Nanoscale Solid-State System
Authors: Wang Zheng Ling , Zhou Ming , Zhang Wei , Gao Chuan Yu , Cao Guo Rong
Published: August 2011

We propose a novel scheme to generate nanoscale optical trap for cold atoms near the tapered Ag nanotip, in which we take a microdisk cavity near the nanoscale trap and form a nanoscale solid-state system to realize the loading of the isolated cold atoms. We calculate the field distribution by the FDTD method near the nanotip, and discuss the intensity, the optical potential and van der Waals potential as well as the dipole force for 87Rb atoms. We find that the total potential and dipole force can form an attracting nanoscale trap for cold atoms with red-detuned field and it can realize the effective trapping and manipulation of the isolated atoms, which can enable efficient fluorescence photon collection and strong coupling in the coupled optical fiber.
Study on the Relation between Waxberry Color and its Nutrition Composition Based on BP Neural Network
Authors: Zhao Hong Xia , Liu Zhi Xia , Luo Zhi Yang , Xiao Guan Yun
Published: August 2011

The color of farm produce is a very important index of quality, its nutrition is correlative with itself color. At present, most of the analyses for pigment and nutrient composition still depend on chemical method; therefore the relation is studied between waxberry color and its nutrition composition based on BP neural network. The conversion relation is expressed by three-layer BP network, which hidden layer has 11 node numbers and its transfer function adopts tansig function; transfer function of output layer selects purelin function. The neural network and linear model of nutrition composition is compared respectively. The MSE value of linear model is 0.300892, and that training error of neural network is 0.0219585. From this result，we can find that the conversion relation between waxberry color and its nutrition composition is a complex non-linear relation, so neural network is adopted to complete this conversion.
Energy Entropy Used in Identification Based on Motor Imagery EEG
Authors: Dan Xiao
Published: August 2011

Subjects are identified by classifying motor imagery EEG signal. Energy entropy was used to preprocess motor imagery EEG data, and the Fisher class separability criterion was applied to extract features. Finally, classification of of extracted features was performed by a Linear discrimination analysis method. Four types motor imagery EEG of three subjects was classified respectively. The results showed that the average classification accuracy achieved over 85%, and the highest was 88.7% on tongue movement imagery EEG
Decision Support System for Good Quality Flue-Cured Tobacco Based on Knowledge Model
Authors: Li Fo Lin , Yang Huan Wen , Zhang Xi , Hu Xiao Man , Zou Wei , Liu Yang Zhong
Published: August 2011

In order to improve the mathematical description quantitatively, and support decision in tobacco crop knowledge. A Good quality flue-cured tobacco production and management decision support system (GQFKMTDSS) has been designed and developed applying JSP under the Windows Server environment, based on good quality flue-cured tobacco knowledge model with system analysis methods and mathematical modeling techniques. The system helps for forecasting function and guiding decision-making to good quality flue-cured tobacco.
Spatial and Temporal Analysis of MODIS Vegetable Index of Different Grassland Styles
Authors: Hu Zhuo Wei , Li Shan Shan , Wang Xiao Shuang , Xu Feng
Published: August 2011

This paper mainly reports the annual spatial variation of primary types of the grass in the study area through MODIS NDVI and EVI. First of all, we analyze each type invariably characteristic curve of monthly vegetation index in the area severally and analyze the real-time characteristics about different vegetation index of the same type to study the feature of grass in each growth stage. It turned out that the variation trend of each vegetation index is identical in general and the variation of each month is a bit difference. The value of NDVI is bigger than EVI and so is the amplitude of fluctuation. The vegetation index of grass achieves the maximum value in July except the Stenothermal desert grass which achieves it in August, and descends to the minimum in February. It turned out that the yield is filled for grass in July and August. Then we use the image taken in July to analyze the spatial status and take the density segmentation by Maximum synthesis and take two kind of image. Results show that two kinds of vegetation index reflect grass type of spatial continuity and difference. The grading of EVI and NDVI is able to reflect adequately grass type of spatial distribution, and EVI reflects a gradual change of grassland types of space more than NDVI. According to the main grass type vegetation index analysis of the spatial and temporal variation characteristics of grassland, accurate embodies the basic condition can type for further grass information extraction work and grassland dynamic monitoring research which provides the main material basis and basic work.
Hardware Design of Soil Moisture Wireless Monitoring System
Authors: Lv Xia Fu , Luo Ping , Yang Hai Lin , Chen Yong
Published: August 2011

Proper soil moisture content is one of the necessary conditions for crop growth and steady yield. The soil moisture real time measurement is the basis of reasonable irrigation and an effective way for saving water resources. This paper presented a real-time monitoring system of volumetric soil moisture content. The system consisted of field data collection terminal and monitor center. The data is transmitted by wireless communication between the measurement field and monitor center. The soil moisture content is obtained by measuring the sensor frequency variation with the soil dielectric constant. With solar cell, solar energy was collected and stored in accumulator cell to provide power supply for field data collection terminal. The experimental result shows the system is operating good and working stably, it is promising to be used for real time measurement of soil moisture.
Selective Catalytic Reduction of Nitric Oxide with Fe-Mn-Ce Metal Oxide-Based Catalysts
Authors: Zhao Hai , Xu You Ning , Liu Jun Qing
Published: August 2011

Nanosized cerium-manganese ferrite particles were prepared by co-precipitation approach. The structural evolutions and morphological characteristics of the nanopowder were investigated using X-ray diffractometry, transmission electron microscopy and thermo-gravimetry. XRD results showed that particles with crystallite size in nanometer scale were formed. TEM studies showed the morphology of the prepared cerium-manganese ferrite with a crystallite diameter of 20 nm at the calcination temperature of 500°C for 4 h. The catalyst showed high activities for SCR of nitric oxide with ammonia.
The Design and Analysis of Pulse Generator Electronic Circuits Based on Avalanche Transistor
Authors: Zhou Jin Cheng , Zhang Ming Hui
Published: August 2011

Avalanche transistor is a ideal device which can provide quick response and high peak power simultaneously, and this device is cheap. A pulse generator based on avalanche transistor is designed in this paper; this generator can generate transient current pulse. This generator can be easily triggered, what is more, the performance of this generator is stable and it has a well-behaved load capacity. Therefore, this generator is suitable for using as the magneto-optical switch in the all-optical communication network. Future work will focus on further shorten the duration and rising time of the pulse.
The Judgment Method Based on F-Test for the Best Clustering Scheme of Self-Organizing
Authors: Zhang Dong Sheng , Ji Chao
Published: August 2011

To avoid the optional and uncertainty when judge self-organization clustering results, we have introduced the F-test method what have used in mathematical statistics. The method calculat and compares inner-class distance and inter-class distance respectively what from various clustering schemes, and then get the best clustering scheme through the F-test analysis. The experiment results show that the method is athematically proved rigorously, program operation is stable and reliable, and with larger value both in theoretical research and engineering application.
A New Vegetable Greenhouse Environmental Monitoring System Based on Wireless Sensor Network Technology
Authors: Bai Qiu Chan , Zheng Rong Jian
Published: August 2011

A wireless measurement and control system for vegetable greenhouse is developed for the sake of overcoming the shortcoming of the wired measurement and control system such as complex wiring and low anti-interference capacity. In this environmental monitoring system, including the hardware design, software design and energy control strategy design, then we describe a comprehensive system testing process. In the hardware system testing, testing data verified the monitoring node performance. At last simulation data shows that the improved multi-hop network transmission protocol has obvious advantages.
Characterization and Humidity Sensing Application of ZnO-TiO2 Nanocomposite
Authors: Pandey Narendra Kumar , Tiwari Karunesh , Roy Akash
Published: August 2011

Paper reports morphological and relative humidity sensing studies of ZnO-TiO2nanocomposite powder pellets obtained through solid-state reaction route. When exposed to humidity, resistance of pellets decreases with increase in relative humidity from 10-90%. Sensing element with 15 weight % of TiO2in ZnO shows best results with maximum sensitivity of 9.08 MΩ/%RH in 10-90% relative humidity range. This sensing element manifests smallest crystallite size of 71 nm as measured from XRD and lowest grain size of 207 nm calculated from SEM micrograph. This sensing element has the lowest value of activation energy, and hence higher electronic conduction.
Mechanical and Friction-Wear Properties of MoS2 Al-Matrix Self-Lubricating
Authors: Qi Xiao Qian , Zhang Xu Ping
Published: August 2011

Al-matrix self-lubricating which added MoS2 as solid lubricant was prepared by casting under variation in content of Si、Fe、Mn、MoS2、Cr3C2. Friction and wear behavior were investigated on MPX-2000 friction and abrasion machine. The microscopic structure and phases were analyzed by metallographic microscopic and XRD. The results show that the main factor influencing friction coefficient is Si, it can reduce the wear rate. Addition of MoS2 can reduce friction coefficient, Fe is used to improve the mechanical properties. Cr3C2 enhances the wear resistance.
Research on Impact Localization in Composite Materials Using Array Signal Processing and Lamb Wave
Authors: Su Yong Zhen , Liu Xin Wen , Li Da Yu , Wang Xin Bing , Zhang Yu Heng
Published: August 2011

Impact localization is one of the major concerns in maintenance of aircraft structures built from composites. A lot of different techniques like acoustic emission, optimization technique based on system are nowadays investigated to identify impact location. But the method to identify impact position in complex composite structure with high accuracy in real time has not been completely established. In the present work, a new efficient method is proposed for identifying impact location in real and complex composite structure based on array signal processing and Lamb waves. There are two steps in the proposed method. The first step is to estimate the direction- of-arrival (DOA) of impact source using continuous wavelet transform (CWT) and array signal processing; the second step is to estimate the distance between impact source and the coordinate origin based on propagation characteristic of Lamb wave and CWT. The composite panel with stepped thickness of a real and complex aeronautical tank is used to verify the present methodology. The result shows that the present method may identify impact location fast and accurately.
The Application of Neural Network in Dam Safety Monitoring
Authors: Zhang Wei , Zheng Dong Jian , Wang Cong Cong
Published: August 2011

Dam safety monitoring is an important means for remaining the dam safe, while stress-strain monitoring has been an extremely important part in the dam monitoring. Sometimes the traditional forecasting methods are not high accuracy, so, in order to improve the accuracy of prediction. This paper presents a dam strain prediction model based on Least Squares Support Vector Machines(LS-SVM). Applied in one dam, LS-SVM shows the advantages of good robustness and high prediction accuracy. The strain prediction accuracy improves a lot than using the traditional stepwise regression method, so it provides reliable and effective ways and means in dam strain analysis.
Study on Nonlinear Vibration in Dynamic Turning Long-Thin Axis Process
Authors: Feng Jing , Zhang Jian Li
Published: August 2011

Nonlinear vibration in turning long-thin axis becomes one of the instable factors of the quality. Mathematical models are built based on this dynamic process and simulation program is organized by common software. Poincare and phase diagram of this model are obtained and the important influence factors can be concluded from these diagrams. The results provides theoretical base for improving stability of turning process.
Cutting Parameters Optimization of Turning Titanium Alloy Diaphragm Disk Based on Surface Topography Simulation
Authors: Zhang Wei , Zheng Min Li , Cheng Ming Ming
Published: August 2011

A model of micro surface topography interacted by the tool vibration is constructed according to working process characteristics and quality requirements of cutting titanium alloy diaphragm disk in high-speed; based on established micro surface topography model, an optimization methodology is designed by using genetic algorithm and then parameters optimization of titanium alloy diaphragm disk turning in high-speed and surface topography simulating system is developed. By the comparative analysis of the experiment and simulation result, it is easy to find that the simulation results have high consistency with the tested results of surface topography and it could meet the surface quality requirements by using optimized cutting parameters, and the established system is credible and practical.
Modal Analysis on Fluid–Structure Interaction System of a Large-Scale Gas Control Valve
Authors: Cao Fang , Wang Yong
Published: August 2011

According to the real structure and work condition of a large-scale gas control valve used in recycling generating electricity project, a modal analysis modeling of fluid-structure interaction system is set up and the vibration in fluid-structure interaction is studied. The fluid force on the valve plug when the control valve at different openings is analyzed. According to the modal computing of the plug in fluid environment, the vibration frequencies of the plug are obtained. The influence on vibration frequency of fluid-structure interaction is showed, which relate to vibration modal of plug. The change of plug frequency at coupling and uncoupling condition is investigated. All of these are in favor of vibration characteristic analysis, vibration fault diagnosis of control valve system and realizing design optimization in plug dynamic characteristics. These are of great practical significance for advancing study on large-scale control valves.
Monte Carlo Simulation and Applications in Design and Manufacture of Nanostructures
Authors: Hu Xing Lei , Chen Jia Xuan , Liang Ying Chun
Published: August 2011

This paper provides a review of Monte Carlo (MC) method and its applications in mechanical engineering. MC simulation is a class of computational algorithms which require repeated random sampling and statistical analysis to calculate the results. The basic principles, formulas and recent development of Monte Carlo method are firstly discussed briefly, and then the applications of MC simulations in the design and manufacturing of nanostructures are reviewed. Finally, we briefly introduce MC simulation of morphology evolution of machined surface, which come from our recent work.
Influence of Shear and Gyroscopic Effect of Grinder Spindle on Critical Speed
Authors: Li Chang He , Zhao Hua Yang , Ding Yu Cheng
Published: August 2011

This study was focused on the theoretical modeling and numerical simulation about the shear effect and gyroscopic effect of spindle system of high-speed grinder. Based on the rotor dynamics, a theoretical model was established using the transfer matrix method. The moment balance equations, and the transition matrix, the state vector, field matrix of spindle system of ultra-high speed grinder were analyzed and calculated. The results showed that shear effect reduced the critical speed in various orders, and its influence on higher orders was more severe than on lower orders. Furthermore, it could be seen that gyroscopic effect increased the critical speed in various orders, and it was sensitive in higher orders. It could be found that the increase of fifth order critical speed reached 16.6% due to gyroscopic effect, while the minimum increase of critical speed was 1.8% due to gyroscopic effect.
Study on Uniform Magnrtorheological Finishing Technology with Changeable Removal Rate Model Based on Rheological Effect
Authors: He Xin Sheng , Gao Chun Fu , Wang Bin , Luo Zhi Yong
Published: August 2011

At present, the finish machining process of workpiece with free-form surface has the disadvantages of complex trajectory planning, low machining efficiency and precision. To solve these problems, a material removal model whose removal rate model can change with the profile of the workpiece is proposed in this paper. The working mechanism of this method is described as follows: the rheological effect of magnrtorheological fluid is used to change the magnetic field distribution in finishing areas; then the finishing pressure distribution is changed, that makes the material removal rate of every point in the contact area be approximately equal so the aim of uniform removal is achieved. The experiments identify the quantitative relationship between magnetic field intensity and finishing pressure. Contrast experiments of finishing and removal effects are performed under the different conditions of magnetic field distribution. The experiments results show that the proposed method is feasible and this method has the potential of obtaining the ultra precision.
High-Precision Positioning and Speed Smooth Transition Control Algorithm for Terminal Point of Micro-Line Segment
Authors: Huang Zhui Liang , Lin Shu Wen , Jiang Dao Ying
Published: August 2011

In allusion to the problem of data sampling interpolation error which exists in continuous micro-line segments interpolation algorithm with acceleration /deceleration control, this paper proposes a high-precision positioning and speed smooth transition control algorithm for terminal point of micro-line segment. The linear acceleration/deceleration mode was taken as an example to derive a motion control algorithm, which can eliminate the rounding error of the interpolation with fine adjusting the reserved parameters of acceleration /deceleration process when micro-line segment starting point and terminal point velocity are not zero. Simulation analysis and experiments of motion control shows that the algorithm greatly improves the control accuracy of the joint point position of micro-line segments, achieves the continuous smooth transition at the feed speed of the joint point of adjacent line segments and the uniformity of the velocity in specific line segment.
Dynamics Characteristic Analysis of Deliberate Mistuned Bladed-Disk System in Compressor Based on CMS Mothod
Authors: Yuan Hui Qun , Zhang Liang
Published: August 2011

In this paper first,a method combining dichotomy and finite element is presented which identify elastic modulus parameters of mistuned bladed based on the test data of blade static frequency and simulation blade deliberate mistuned by change elastic modulus.Then, dynamic characteristics of deliberate mistuned 10Hz and 41Hz bladed-disk system were analyzed in work rotating speed based on CMS mothod, respectively. The exciting force of airflow exert on costal margin of blade tip.According to dynamic test results,the incentive order is 4. The analysis results show that along with the mistuning frequency difference increases,the largest amplitude of blade is becoming smaller(except tuned system) , and scheme of large frequency difference 41Hz deliberate mistuned (scheme Ⅱ) better than scheme of small frequency difference 10Hz deliberate mistuned (scheme Ⅰ) for vibration reduction of bladed-disk system in work rotating speed for 11300r/min. The analysis results are consistent with the dynamic test results.
Mechanical Behavior of the Amorphous/Nanocrystal Ni-Mo Alloy
Authors: Chen Wei Zeng , Xu Hong , Jing Bao De , Li Ning
Published: August 2011

The amorphous alloy application is limited because of its brittleness property. Based on the grain structural characteristics of nanocrystal alloys, the mechanical behavior of the amorphous/nanocrystal Ni-Mo alloy is investigated in this text. The microstructure of the deposit and the crack propagation were discussed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results show that amorphous/nanocrystal Ni-Mo alloy has a higher microhardness, a strong binding force between a certain thickness coating with the substrate.