bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Mg Doping on the Microstructure and Properties of α-Al2O3 Transparent Ceramics
Authors: Zhang Xiao Juan , Qiao Guan Jun , Zhang Xiao
Published: July 2011

High purity Al2O3powder was used as raw material and MgO was used as additive to sinter alumina transparent ceramics in hydrogen atmosphere. EBSD image showed that, with the increase of the MgO content, the grain size decreased from 200μm (when no Mg was doped) to about 20μm (when the Mg doping amount was 1.0wt%), indicating that MgO had an inhibition effect on the grain growth. XRD analysis showed that the doping of MgO did not lead to the formation of new phases. A further refinement of cell parameters revealed that, when the doping amount reached 1.0wt%, lattice distortion occurred and the cell volume increased by about 80%, which was attributed to the formation and diffusion of oxygen vacancies. The Egmode at ν=575cm-1 revealed by Laser Raman Spectroscopy suggested that AlO6octahedra were distorted with the increase of the MgO content. And the frequency change of the A1gmode at ν=642cm-1reflected the combined effect of ion mass and mechanical constant. Measurement of the optical transmittance indicated that, after the doping of MgO, a small amount of MgAl2O4phase formed at the grain boundary, causing the transmittance to increase first and then decrease with the increase of the MgO content. And analysis of the dielectric properties showed that the change of the dielectric constant and loss with the frequency at room temperature resulted from ion relaxation polarization induced by the weakly bound ions in the AlO6octahedron.
Adaptive Neuro-Fuzzy Inference Approach for Back Analysis of Workability
Authors: Shan Zhi , Shi Jian Jun , Xiong En , Wu Xian Lei
Published: July 2011

The usual research method, on rheology of fresh self-compacting concrete, is that the regression models between rheological parameters and workability were established, and then the rheological test was operated to control fresh SCC. But, there is no rheometer used widely on site, already. So this paper developed an adaptive neuro-fuzzy inference approach of the back analysis of workability on fresh SCC rheology, and workability tests can be taken to inverse the rheological parameters, by adaptive neuro-fuzzy inference system. In order to check the correctness of this approach, a rheological problem of fresh SCC was solved by it, and the inversion results were in good agreement with the rheological parameters, and the predication accuracy of ANFIS models was quite sufficient to meet the engineering requirement.
Numerical Simulation of the Flow of Inflatable Cover Based on FLUENT
Authors: Wang Jian Hua , Xiao Chang Zhi , Wang Jing Hui , Cai Li Gang , Cui Li Shui , Wang Tie Jun
Published: July 2011

The inflatable cover was used in the low-temperature blackbody radiation source; the function of the external gas separation had great influences on blackbody radiation source performances. This paper presents a new way for performing numerical simulation for the three-dimensional inner flow field analysis of new inflatable cover and blackbody radiation source cavity by using the FLUENT software of CFD. By comparison, the simulation results and the acetone tracer particle experiments revealed the reason of the outside air into the cavity caused frost and dew, so we proposed a number of methods to reduce air convection inside and outside of the cavity for the using inflatable cover, and it gave theoretical basis guidance for the next optimal design of the new inflatable cover.
The Optimization of the Conditions of Thermal and Pressing Dewatering and the Effect of Conditions on the Burning Characteristic of Lignite
Authors: Wan Yong Zhou , Gao Jun Rong , Xiao Lei , Tao Xiu Xiang , Liu Jiong Tian
Published: July 2011

The paper was to optimize the conditions of thermal and pressing dewatering of lignite based on four factors three levels of Orthogonal experiment and to study the effect of conditions on lignite burning characteristic. The results show that the importance to the dehydration rate of lignite is in turns, temperature, pressing time, pressure, particle size; and the optimizing condition is temperature 220°C, pressure 6MPa, pressing time 40min, and the particle size ratio 3 to 7. Thermo gravimetric analysis had been carried out to study the burning characteristic of the dewatered lignite. The results show that the burning characteristic temperatures: Preliminary release of volatile temperature, ignition point, point of maximum weightlessness rate, burnout temperature, are found to be an obvious rise, but the burnout temperature; and the four burning characteristic temperatures will be elevatory with the temperature elevated, pressing time extended and pressure increased.
Wear Behaviour of Pure Ti with a Nanocrystalline Surface Layer
Authors: Wen Ming , Wen Cui'e , Hodgson Peter D. , Li Yun Cang
Published: July 2011

A nanocrystalline (NC) layer with the thickness of 30 µm was produced on pure titanium surface by surface mechanical attrition treatment (SMAT). Microstructure observation indicated that the grain size increases with depth from the treated surface. The friction coefficient decreases and the wear resistance increases with the SMAT sample as compared to its coarse-grained counterpart. The improvement of the wear properties could be attributed to the higher hardness of SMAT sample.
Study on Properties of Leucite for Dental Porcelain Compositions
Authors: Sui Li Na , Yu Li Yan , Dong Li Feng
Published: July 2011

Leucite crystal was prepared using SiO2-Al2O3-K2CO3-Na2CO3as raw materials and adopting melt quenching and appropriate heat treatment temperatures. The crystal was characterized and analyzed by X-ray powder diffraction, the coefficient of thermal expansion, and biocompatibility. The results showed that appropriate Na2O could advance the growth of leucite, but high concentration facilitates the formation of KAlSiO4crystal. The coefficient of thermal expansion was 24.52×10-6/°C at 600 °C, and thereby the coefficient could be adjusted by adding appropriate amount of leucite. The biocompatibility of leucite was almost the same as the Songfeng powder for clinical applications.
Performance of Polyaspartic Ester Polyurea in Marine Engineering Protection
Authors: Yang Lin , Lu Ping
Published: July 2011

In this work, the natural diffusion method and rapid chloride ion penetration method (RCM) are used to study the performance of polyaspartic aster (PAE) coating in marine structures protection. The ability of concrete resistance chloride ion permeability in marine environment is tested by such two methods. The results obtained by the two methods are compared, they agree well. The paper also study the change chloride ion permeability coefficient of marine concrete with different coating thickness and use scanning electron microscopy (SEM) to microscopic analysis. From microscopic research, only a few tiny holes appear in the sample section after 6 months corrosion. Compared with the samples without corrosion, the PAE coating still remains homogeneous and dense.
Viewpoints of Dominant Environmental Factors Influencing Algal Blooms
Authors: Guan Di , Gao Da Wen , Ren Nan Qi , Li Yi Fan
Published: July 2011

Harmful algal blooms (HABs) are generally known as excessive phytoplankton growth or rapidly concentrate to high biomass. This study summarized the situation of HABs in China, and discussed possible dominant factors stimulating algal blooms by analyzing several actual HABs cases. It was manifested nutrients may affect algae concentration principally, but such impact tended to decease with degradation of background water. Meanwhile the hydrological and meteorological factors expressed greater correlation to chlorophyll concentration under multiple coupling effects of complex environmental factors. For the complex mechanisms, the determination of principle factors which stimulate excessive algal blooms effectively still need further researches, which are suggested to conduct under overall considerations on 3 scales: macro dimension, medium dimension and micro dimension.
Linear Instability Analysis of an Annular Swirling Viscous Liquid Jet
Authors: Yan Kai , Lv Ming , Ning Zhi , Song Yun Chao
Published: July 2011

A three-dimensional linear instability analysis was carried out for an annular swirling viscous liquid jet with solid vortex swirl velocity profile. An analytical form of dispersion relation was derived and then solved by a direct numerical procedure. A parametric study was performed to explore the instability mechanisms that affect the maximum spatial growth rate. It is observed that the liquid swirl enhances the breakup of liquid sheet. The surface tension stabilizes the jet in the low velocity regime. The aerodynamic force intensifies the developing of disturbance and makes the jet unstable. Liquid viscous force holds back the growing of disturbance and the makes the jet stable, especially in high liquid velocity regime.
Research on Hot Deformation Behavior of 3003 Al Alloy Prepared by Different Melt-Treatment Methods
Authors: Chen Gui Qing , Fu Gao Sheng , Chen Hong Ling , Yan Wen Duan , Cheng Chao Zeng , Zou Ze Chang
Published: July 2011

3003 Al alloy with different metallurgical quality were obtained by different melt-treatment methods, which were deformed by isothermal compression in the range of deformation temperature 300-500°C at strain rate 0.0l-10.0 s-1with Gleeble-1500 thermal simulator. The results show that the material is sensitive to positive strain rate. The hot deformation activation energy (Q) bears linear relationship with inclusion content (H) of 3003 Al alloy prepared by different melt-treatment, Q=35.62 H+171.58, the activation energy of 3003 Al alloy prepared by high melt-treatment is the lowest (174.62 KJ×mol-1), which is beneficial to the material hot plastic deformation. The critical strain of 3003 Al alloy prepared by different melt-treatment methods is investigated through the work hardening rate. Finally, the critical conditions of the investigated alloy were determined to predict the dynamic recrystallization occurrence in the paper.
Silk Protein Assisted Ex Vivo Remineralization of Enamel-Like Microstructure
Authors: Tian Kun , Peng Min , Wu Ping , Liao Chu Hang , Huang Fa Yin
Published: July 2011

Based on the basic theory of molecular recognition, we designed an organic molecules model that spontaneously form three-dimensional fibrillar scaffolds to induce the crystallization of hydroxyapatite to synthesized enamel-like calcium phosphate/hydroxyapatite under a controllable way in vitro. Cross-linking of collagen on the dentin surface and silk fibroin with N,N-(3-dimethylaminopropyl)-N'-ethyl-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) was optimized by varying the NHS/EDC molar ratio at constant EDC concentration. CaCl2 and Na3PO4-12H2O solution was added with Ca: P odd as 1.67:1 after conjugated. The results showed that the dentinal tubule were blocked by neonatal hydroxyapatite layer which has a continuous structure of columns crystal with size of 10-40nm. Furthermore, there were column crystal with parallel direction inside, similar to the crystal array in the top of enamel rod. The results suggest that silk protein monolayer may be useful in the modulation of mineral behavior during in situ dental tissue engineering.
The Casting Process Design and Simulation of the Rear Wearing Plate of 6/4E-AH Slurry Pump
Authors: Yin Ying Jie , Han Yan Jun , Zhi Xiao Hui
Published: July 2011

The casting process design and simulation of the rear wearing plate of 6/4E-AH slurry pump were presented in this paper. The casting process design principle, process parameters, points of attention, and the simulation parameters were introduced. Huazhu CAE was used to simulate the casting process. The STL document used in Huazhu CAE was converted from the 3D molding of the casting process using the Solidwork software. The simulation results and practical production showed that the casting process can reduce shrinkage defects of the casting. And practical production also showed that the produced rear wearing plates, according to the technique, meted the quality demands, such as no crack, no misrun, etc, and they were successfully used at the thermal power plants and concentration plants.
Large Eddy Simulation of Hydrogen-Fueled Supersonic Combustion with Strut Injection
Authors: Liu Hao , Song Wen Yan , Yang Shun Hua
Published: July 2011

In order to obtain more accurate simulation results and properties of combustion in supersonic combustion flow fields, modules of large eddy simulation of reactive turbulent flow and fifth-order WENO scheme was developed. Large eddy simulation of hydrogen-fueled supersonic combustion with strut injection was conducted. Simulations results compare were with experimental measurements, which including wall pressure, velocity, velocity fluctuation and temperature.
Correlations among Various Parameters in Car-Following Models with NGSIM Trajectory Data
Authors: Yang Ling Xiao , Zhao Xiao Mei , Zheng Jian Feng
Published: July 2011

Based on NGSIM empirical trajectory data, we focus on verifying the correlations among various parameters in car-following models. The data is preprocessed primarily by symmetric exponential moving average filter. Then, based on SPSS, we explore the preprocessed NGSIM trajectory data by plotting scatter diagram and correlation analysis. The results show that the acceleration of the following vehicle is obviously proportional to the velocity difference and acceleration difference between the following and the preceding (next preceding) vehicle, as well as the product of such velocity difference and the following vehicle’s velocity. Furthermore, we analyze the delay time by using time series correlation formula and modified R/S and V/S statistics methods.
Comparative Study on Corrosion of Mild Steel in Natural and Simulated Marine Environment
Authors: Zhao Xiao Dong , Xi Guang Feng , Yang Jie
Published: July 2011

Different zones of the marine environment were simulated by a designed marine corrosion test device in laboratory, through which the corrosion rate was tested by weight loss method applying separate specimens and electrically connected specimens, separately, and the test data were compared with those by seawater exposure method. The results showed that the corrosion in splash zone was the most severe whether for separate specimens or electrically connected specimens, and for the latter, the experimental data were more reasonable to simulate a continuous marine structure throughout the different zones in marine environment. The feasibility and reliability of the simulation device and the experiment method were also verified.
Comparison of Two Methods in Solving Rayleigh Dispersion Curves
Authors: Qin Bo , Cao Yan Mei , Xia He
Published: July 2011

The Rayleigh dispersion curves of multilayered soil are calculated by means of thin-layer method and rapid scalar method, respectively, in which two-layered and three-layered soil model are adopted. In addition, the disperse properties of multilayered soil are analyzed, and it is found that thin layer method is superior to rapid scalar method in low frequency domain, while in the high frequency domain it has little difference between each other.
Effect of Non-Sinusoidal Oscillation Parameters on Mold Flux Consumption Rate
Authors: Wang Hong Ming , Zhang Ting Wang , Yan Yong Qi , Song Bang Min , Li Gui Rong
Published: July 2011

According to the rule of non-sinusoidal oscillation of continuous casting mold, a mathematical model was established to study the effects of oscillation parameters on the consumption rate of mold flux. The results indicated that the mold flux consumption rate is remarkably affected by the non-sinusoidal factor. This proves that the non-sinusoidal oscillation of mold contributes to increase the flux consumption. Moreover, the amplitude and frequency of mold oscillation have effects on mold flux consumption rate. The non-sinusoidal oscillation parameters must be optimized.
Study on Wear Behaviour of Ceramics/1Cr18Ni9Ti Wear Components in H2O2 Solution
Authors: Bai Xiu Qin , Yuan Cheng Qing , Li Jun
Published: July 2011

The wear performances of three types of ceramics (ZrO2, Al2O3, Si3N4)/1Cr18Ni9Ti stainless steel rubbing pairs were analyzed under 0% (pure water), 10%, 30%, 50%, 70% and 90% hydrogen peroxide (H2O2) solution. The results showed that, under different concentrations of H2O2 solution, the worn surface roughness of the 1Cr18Ni9Ti stainless steel was bigger than that under pure water when the counterpart was ZrO2 ceramic ball, while the worn surface roughness of the 1Cr18Ni9Ti stainless steel was smaller than that under pure water when the counterpart was Al2O3 ceramic ball. For the ZrO2, Al2O3, Si3N4 ceramics ball, the average worn surface roughness of Al2O3 ceramic ball was the smallest, and the average worn surface roughness of Si3N4 ceramic ball was the biggest. When the concentration of H2O2 solution was 10%, the metal particles from the ZrO2/1Cr18Ni9Ti and Al2O3/1Cr18Ni9Ti stainless steel rubbing pairs had the features with large size and bright surface. The surfaces of the metal particles were oxidized clearly when the concentrations of H2O2 solution were 70% and 90%.
Development of A Two-Equation Turbulence Model for Hypersonic Shock Wave and Turbulent Boundary Layer Interaction
Authors: Liu Jing Yuan , Lee Chun Hian
Published: July 2011

For hypersonic compressible turbulence, the correlations with respect to the density fluctuation must not be neglected. A Reynolds averaged K-ε model is proposed in the present paper to include these correlations, together with the Reynolds averaged Navier-Stokes equations to describe the mean flowfield. The K-equation is obtained from Reynolds averaged single-point second moment equations which are deduced from the instantaneous compressible Navier-Stokes equations. Under certain hypotheses and scales estimation of the compressible terms, the K-equation is simplified. The correlation terms of the fluctuation field appearing in the resulting K-equation, together with a conventional form of the ε-equation, are thus correlated with the variables in the average field. The new modeling coefficients of closure terms are optimized by computing the hypersonic turbulent flat-plate measured by Coleman and Stollery [J. Fliud Mech., Vol. 56 (1972), p. 741]. The proposed model is then applied to simulate hypersonic turbulent flows over a wedge compression corner angle of 34 degree. The predicting results compare favorably with the experimental results. Also, comparisons are made with other turbulence models. Additionally, an entropy modification function of Harten-Yee’s TVD scheme is introduced to reduce artificial diffusion near boundary layers and provide the required artificial diffusion to capture the shockwaves simultaneously.
Unsteady Characteristics of Breakdown Vortices over Delta Wing
Authors: Zhang Ming Lu , Yang Yi Ren , Lu Zhi Yong , Lu Li
Published: July 2011

Experiment of unsteady pressure measurement on the surface of wing with 75° sweep delta wing has been carried out in a wind tunnel in order to investigate unsteady characteristics of breakdown vortices over delta wing after the leading edge vortices were breakdown. The result of experiment shows that alter of RMS pressure fluctuations and fluid state of leading edge vortices on the top surface of delta wing are correlative. At the angle region with vortex breakdown, RMS of pressure fluctuations are very huge, similarly buffeting strength of delta wing are large. With increasing angle of attack, alter of buffeting strength is in accordance with RMS pressure fluctuations. Analysis of the pressure signal shows the spiral wave of the breakdown vortex flow over the wing is the primary part of whole RMS pressure fluctuations. Delta wing produces buffeting because of the spiral wave.
Energy Performance of a Building-Integrated Dual-Function Solar Collector in Passive Space Heating Mode
Authors: Luo Cheng Long , Xiong Ji Hai , Fan Min
Published: July 2011

The building-integrated dual-function solar collector has two independent operating modes: passive space heating mode in cold days, and solar water heating mode during hot days such as the summer. The novel system avoids summer overheating in hot climate and water-freezing in cold climate, meanwhile remains low operating cost as a passive solar heating system. In this study, the energy performance of the novel system in passive space heating mode was studied by experiment and numerical simulation. The experimental and numerical results show that the system performed a high ability in utilizing solar energy for building when working in passive space heating mode and the value of the transient operating efficiency generally kept as a constant.
Transient Simulation of Electromagnetic Field during EMCC Process
Authors: Wang Hong Ming , Yang Bo Feng , Song Bang Min , Zhao Yi Nan
Published: July 2011

A transient analysis mathematic model was established via ANSYS. The variation laws of magnetic induction density, induced eddy current and electromagnetic force in molten steel changing with the high frequency sine exciting current were investigated. The results indicate that the magnetic induction density and induced eddy current in molten steel vary at the same frequency as exciting current. Moreover, the variations of magnetic induction density and induced eddy current are not in step with exciting current. This proves that the high frequency electromagnetic field in mold and steel is not a time-harmonic wave. The electromagnetic force varies at the double frequency of the exciting current. When the exciting current reaches the amplitude value, the electromagnetic force is close to the max value, whereas when the exciting current returns to zero, the electromagnetic force is not zero. At the same time, there is partial electromagnetic force reversing its direction. If the reversed electromagnetic force is expanded seriously, the fluctuation of liquid level is induced, so it must be controlled.
Parametric Effect on Bidirectional Moving Vehicle Load Identification
Authors: Yu Ling , Wang Xue Gang
Published: July 2011

Parametric effect on bidirectional moving vehicle load identification from plate bridge responses is studied in this paper. The equation of motion of a plate bridge-bidirectional vehicle system is formulated based on Hamilton principle and is rewritten in a state space form, the bidirectional moving load identification problem is considered as a damped least-squares problem and further solved with the regularization method. Finally, the effect of parameters on identification accuracy is investigated in order to evaluate the effectiveness and robustness of the bidirectional moving load identification method proposed in a companion paper. Some numerical simulations show that the proposed method is correct and effective for identifying the bidirectional moving vehicle loads from bridge responses with an acceptable accuracy, but the selection of parameters should be carefully considered in the identification process.
A Novel Scheduling Algorithm Based on Game Theory and Reinforcement Learning
Authors: Zou Wen Sheng
Published: July 2011

In this paper we proposed a new dynamic scheduling algorithm for power scheduling problem. The algorithm is based on game theory and reinforcement learning approach. We compared the performance of our algorithm with that of online bin packing and MAB algorithm. We observed that our algorithm performs better than online bin packing when there is a variation in the deadlines. This is because our algorithm schedules the requests on the basis of their actions and the probability of missing the deadline and online bin packing algorithm schedules requests based on the sequence of requests as they arrive. We observed that our approach is more useful, when scheduling requests repeat themselves for long duration.
A Rapid Matching Algorithm Based on Filtering Feature Points
Authors: Zhu Hong Bo , Xu Xue Jun , Chen Xue Song , Jiang Shao Hua
Published: July 2011

Matching feature points is an important step in image registration. For high- dimensional feature vector, the process of matching is very time-consuming, especially matching the vast amount of points. In the premise of ensuring the registration, filtering the candidate vectors to reduce the number of feature vectors, can effectively reduce the time matching the vectors. This paper presents a matching algorithm based on filtering the feature points on their characteristics of the corner feature. The matching method can effectively improve the matching speed, and can guarantee registration accuracy as well.
Measure and Control System of an Onboard Micro-Channel Reactor for Hydrogen Production via Methanol Steam Reforming
Authors: Jin Biao , Yao Zhe He , Qian Miao
Published: July 2011

In order to carry out reaction smoothly, a measure and control system of an onboard micro-channel reactor for hydrogen production via methanol steam reforming is developed. A subsystem of temperature control is designed to measure and control the temperatures of reactor and evaporator. Flow control subsystem, including liquid flow control of reactant and mass flow control of reducing gas, is also developed. Virtual instrument technology and graphical programming language LabVIEW are applied to integrate all the control functions in a single program, which makes it convenient for operation and further development. The experimental results validate that the reaction can be carried out successfully under the control of this measure and control system.
The Design of Hydraulic Decontaminating Equipment for Engineering Machinery
Authors: Zhou Jian Zhao , Yang Xiao Qiang , Lu Guo Liang , Ma Kai Ming
Published: July 2011

A type of hydraulic pollutant decontaminating equipment was made in this paper. The decontamination and maintenance means were studied. The circulating decontaminating method was put forward and developed by modularized technique. The hardware of the decontaminating equipment was implemented with single-chip microcomputer and integrated circuit technology. The controlling application program integrated with fuzzy logic and reasoning function was developed. The practical use showed that the decontaminating equipment could be used in the maintenance of hydraulic circuit of bulldozer as well as the other engineering machinery, therefore realizing the quick decontamination and cleaning of hydraulic component and oil on-line purifying.
Research on Automatic Digging Control and Algorithm of the Working Device of Skid Steer Loader
Authors: Liu Bo , Huang Jie , Guo Li Wei , Liu Long
Published: July 2011

Focus on the trajectory planning problem of shovel operations of skid steer loader, a trajectory curve fitting equation is established. By use of the robotics theory and the D-H method, the functional relationship between the kinematics of the working device of skid steer loader and the displacement, position and orientation of boom bucket cylinder is derived, and the driving equation of displacement cylinder is obtained. Based on the requirements of precise trajectory control, an electro-hydraulic proportional position control system for position and orientation control is designed and the state equation of the system is established. By using fuzzy self-tuning PID control algorithm, the outside interference, parameter uncertainty and the error caused by other factors are weakened. The trajectory tracking simulation results demonstrate that: the biggest shovel tracking error is 12.5mm, the designed electro-hydraulic proportional control system can effectively track the trajectory of the working device of skid steer loader in automatic digging process. The rightness of the established model and the effectiveness of the corresponding controller are also proved.
Preparation of Zinc Diacrylate-Modified Montmorillonite/Rubber Nanocomposite with High Thermal Properties
Authors: Cao Yang , Gu Ning , Zhang Jing Lin
Published: July 2011

Organo-montmorillonite (OMMT)/nature rubber (NR) nanocomposites were prepared by mixing method. The microstructure of these composites was characterized by SEM and XRD. The effect of OMMT on mechanical properties and thermal conductivity of the nanocomposites was investigated in detail. SEM and XRD confirmed the intercalated structure of OMMT/NR nanocomposites. The introduction of a small amount of OMMT greatly improved the mechanical properties and thermal conductivity behavior, which was attributed to the nanometer scale dispersion and stronger interactions between OMMT and NR chains.
Probe and Analyze the Influence that Heavy Duty Motor’s Start Exercise over the Power Quality of Circuit
Authors: Li Mei , Zhao Dong Mei , Nijat Yu Sup , Xie Zhi Ming
Published: July 2011

It is based on the monitoring result a motor of 1600KW start of petro-chemical oil refinery in Urumqi , the paper probe and analyze that high-capacity motor’s start exercise bad influence over the power quality of circuit: voltage sag and harmonics current, and take some improving actions based on its features.
The Application of the Wettability of Liquid-Solid in the Manufacture of High and Low Voltage Contacts
Authors: Chen Shi Jun , Duan Pei Lin
Published: July 2011

High or low voltage electrical contact is a kind of pseudo alloy which is mostly composed of a high melting point material and a low one. Liquid-solid wettability is widely used in the manufacture of contact materials and its subsequent processing. This article focuses on several solutions to the difficulties encountered during the process by liquid-solid wettability.
A Test on Oil Film Thickness of a Main Bearing in IC Engines
Authors: Wang Gang Zhi , Hao Yan Ming , Lou Xiao Yan
Published: July 2011

Testing ways and means are introduced to measure oil film thickness of a main bearing in multi-cylinder IC engines with two eddy current sensors. A 4100QB diesel engine is taken as a model to detect the influences of loads and journal speeds on oil film thickness of a main bearing. It can be inferred from the test that the Minimum Oil Film Thickness (MOFT) constantly decreases with the increase of the loads while the journal speed keeps stable, and MOFT constantly increases corresponding to the increase of the journal speeds while loads on the bearing are unchanged.
Railway Passenger Travel Aided Decision System Based on WEBGIS
Authors: Yang Ju Hua , Chen Guang Wu
Published: July 2011

The system goal is fixed as the choice and optimization of passenger travel-transfer station. Then the inquire method of all kinds of travel schedules is proposed and Railway Passenger Travel Aided Decision System(RPTADS) is developed with WEBGIS. The aim of the system is to provide the query result to passengers, and the optimal route will be displayed on the map intuitively, which make the synchronous connection reality between the text inquiry result and the map specific display. In addition, the timetable database of railway passenger transportation could be renewed timely by background decision software according to line conditions.
Laser Metal Deposition Shaping System for Direct Fabrication of Parts
Authors: Zhang Kai , Shang Xiao Feng , Liu Wei Jun
Published: July 2011

The fabrication of metal parts is the backbone of the modern manufacturing industry. Laser forming is the combination of five common technologies: lasers, rapid prototyping (RP), computer-aided design (CAD), computer-aided manufacturing (CAM), and powder metallurgy. The resulting process creates part by focusing an industrial laser beam on the surface of processing workpiece to create a molten pool of metal. A small stream of powdered alloy is then injected into the molten pool to build up the part gradually. By moving the laser beam back and forth and tracing out a pattern determined by a CAD, the solid metal part is fabricated line by line, one layer at a time. By this method, a material having a very fine microstructure due to rapid solidification process can be produced. In the present work, a type of direct laser deposition process, called Laser Metal Deposition Shaping (LMDS), has been employed and developed to fabricate metal parts. The LMDS apparatus consists of four primary components: energy supply system, motion control system, powder delivery system, and computer control system. These components have their specified functions, but work in association with each other.
Shallow Chinese Professional Soccer Club Reform At The Basic Of The whole Nation System
Authors: Liu Feng Yong , Li Jun , Chi Qiang
Published: July 2011

After the founding of our county, the development of the football under the system has accomplished remarkable achievements. Along with the change of social environment, the vocational football in China development in the old country under the system is moving slowly. As soon as possible in order to improve our competitive level of football, it is imperative to finish adapting to the charity kingdom system of social economic environment, improving the professional football clubs, operation mechanism of transformation of government functions, with the development of club football association. Clear the club ownership structure, Ascend the management benefit; the club, Strengthening human resources management construction club related theory, the professional football clubs in China for further development of brainstorm.
An Analysis of Statistical Techniques Applying to Multi-Feature Similarity Comparison between Corpora
Authors: Chen Xiao Xiao , Ge Shi Li , Lin Min
Published: July 2011

Statistical techniques applying to multi-feature similarity comparison belong to the type of goodness-of-fit test which include chi-square test, rank correlation test and Kolmogorov-Smirnov test (K-S test). Experiments show that both chi-square independence test and rank correlation test are subject to the variation of sample size. With the expansion of sample size, the former test achieves the results of significant difference and the latter achieves the results of significant correlation easily. However, both results fail to reveal the actual situation of multi-feature similarity comparison between corpora. Only K-S test, which quantifies a distance between the empirical distribution functions of two samples, can achieve the highest statistical effectiveness.
On-Machine Measurement of Metal Parts Based on Machine Vision
Authors: Wang Zhong Ren , Wu Chun Ling
Published: July 2011

At present, on-machine measurement has received extensive attention due to high efficiency and automatic quality control. In this paper, two applications of on-machine vision measurement of metal parts were introduced. With regard to geometric measurement of small square part, four sides and angle were measured. The procedure of camera calibration, image processing and geometric representation was expounded. For medium square part, four overlapped images were captured by controlling the worktable movement. Size and shape measurement were achieved after image mosaicing. Two application results proved that this kind of on-machine visual measurement is efficient and practical.
Mechanical Behavior of the Amorphous/Nanocrystal Ni-Mo23.56 Alloy Coatings by Electrodeposition
Authors: Chen Wei Zeng , Xu Hong , Li Ning , Jing Bao De
Published: July 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-Mo23.56alloy 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-Mo23.56alloy has a higher microhardness, a strong binding force between a certain thickness coating with the substrate. The tensile stress-strain pattern shows a certain degree of plastic deformation behavior in the coating and tensile fracture surface of radial vein structure, in line with the free volume fracture model.
Research on the Physical Mechanism of Motor Imagery
Authors: Mu Zhen Dong , Wang Jin Li
Published: July 2011

The motor imagery to be widely used in BCI systems, the traditional focus on EEG analysis in feature extraction and classification, this paper of EEG from the left and right imaginary frequency domain, time domain and brain mapping analysis on the EEG, to analyze the characteristics of EEG signals about imagination.
The Research of the Semi-Generative CAPP System Design Based on Rough Set
Authors: Zheng Jian , Mu Zhen Dong , Xiao Hua Bo
Published: July 2011

The current CAPP system has complicated operation, not high degree of intelligence, can not meet the needs of many varieties of small batch production. This paper combines the method of parts surface elements describing and method of parts coding. Formed by the 20-bit code to establish a hybrid coding system, used rough set to extract the parts feature, used the information system method to reduce the rule of processing, and from match the feature and the expert knowledge base, Automatic selection processing methods to generate process routes; use database technology to build parts diagrams and other databases, semi-automatic process documentation.
Experimental Study on the Atomization Behavior of Fuel Nozzle of Low Pollution
Authors: Li Xu , Liu Kai
Published: July 2011

Experimental investigation results of the fuel nozzle group in a heavy-duty gas turbine are presented. Atomization characteristic has great impact about combustion efficiency, ignition performance, and outlet temperature field of combustor. Obtained atomization characteristic about spray particle size and distribution using LDV/PDPA system. These experimental data have provided reliable basis for the nozzle group design, development and operation.
Composite Skin/Stringer Panel Damage Detection Based on Modal Strain Energy and Neural Network Technique
Authors: Hui Jia , Wan Xiao Peng , Zhao Mei Ying
Published: July 2011

This paper proposed a new method to detect the damage of composite skin/stringer panel structure using modal strain energy combined with neural network. The change ratio of element modal strain energy is choosen as damage indicator because of it’s highly sensitivity to the location and severity of structure damage. Neural network here play the role of a tool to indentity the damage according to the change ratio of modal strain energy. To achive this, a three layers neural network model is built and the BP arithmetic is used. The proposed method is validated using a numerical simulation of a composite skin/stringer panel with damages in some elements of its FEM mode, which are simulated by reducing elements’ material stiffness properties. The result shows that, this method is robust, accurate and highly efficient with the maximal error limited in 10%.
Experimental Research on the Flat Belt Axial Motion Induced by Tilted Roller
Authors: Han Feng Lin , Xiong Feng , He Rui Bo
Published: July 2011

To get a deeper understanding of the relationship between the flat belt axial motion (FBAM) and the angles of rollers, a test rig was designed and some experiments were done. The belt axial position was measured though imaging processing. A special filtering procedure was proposed to eliminate the random and systematic errors. Base on the authors’ previous study, the normalized analytical FBAM model was given. By comparing the simulation and experimental results, the effectiveness of the analytical FBAM model was validated. The results also show the relationship between the FBAM and the belt transferring distance is independent of the belt transferring speed.
Design and Realization of Control Circuits of the Micro Milling Machine and the Safety Inspection Function of its Spindle
Authors: Lu Xiao Hong , Jia Zhen Yuan , Wang X. X. , Jia Xu
Published: July 2011

Based on the analyses of the current research status of PC + NC type control system in micro-machining technical field both at home and abroad, an “IPC + PMAC motion controller” type open CNC system is established. Control circuits of the micro milling machine control system are designed, which include the realization of the functions of spindle status display, feeding tables status display, IPC status display, machine tool alarm, interlocking control of the function buttons and the corresponding indicator light control of spindle cooling, spindle lubrication, spindle alarm and spindle running status. Finally, the safety inspection function of the spindle is achieved through writing corresponding PLC programs. The research of this paper can provide reference for the study of the micro milling machine control system.
Heat - Stress Analysis and Structural Improvement of High Temperature Eutectic Fixed-Point Crucible
Authors: Wang Jian Hua , Liu Fei , Wang Tie Jun , Cai Li Gang , Zhao Yong Sheng , Dong Wei
Published: July 2011

When the metal - carbon eutectic gets phase transition, the graphite crucible will be effect by the thermal stress and the phase transformation stress, which often make the crucible rupture, fail to achieve durability requirements, and then affect the research of high temperature eutectic fixed-point’s long-term stability and reproducibility. In order to improve the durability of crucible, the finite element software ANSYS and direct coupling method were used in this paper to analyze the heat-stress of Pt-C fixed-point crucible with sleeve (graphite sleeve) during the solidification. Based on the results of the simulation, we analyze the reasons of the breakdown of the crucible and propose two measures to improve the durability of crucible, which are adding graphite cloth or graphite foil between the crucible and the sleeve. Then we use ANSYS to analyze the two improved crucibles, and prove the effectiveness of these two measures.
Effect of Peripheral Drilling Moment on Critical Thrust Force Using Twist Drill in Drilling Composite Materials
Authors: Tsao Chung Chen
Published: July 2011

Composites have become valuable construction materials in the aerospace, defense, automobile, and civil industries due to their superior mechanical properties. However, there are significant differences between the machining of metals and alloys and that of composites, because composites are anisotropic and inhomogeneous. Drilling with a conventional twist drill is characterized by a relatively large thrust force due to a negative rake and negligibly small cutting speed at the chisel edge. Such a large thrust force causes defects and damages the composites, leading to poor hole quality, and reduced in-service life under fatigue loads. Although significant efforts have been made to realize the thrust force of twist drill, there are few papers reporting the effect of peripheral drilling moment (torque) on delamination in drilling composite materials. In this paper, an attempt is made to develop the critical thrust of the twist drill with peripheral drilling moment using linear elastic fracture mechanics (LEFM) and energy conservation. The theoretical results agree well with the practical experience in industries.
Study on the Framework of Software-Based Open CNC System Based on PC+I/O
Authors: Yan Qun , Xi Dian Gang , Liu Si Shen
Published: July 2011

In this paper was analyzed on the architecture of PC NC system, and was studied design ideas of PC+I/O software-based structure and its exist advantages, and was analyzed with some key technology solutions, comparative study, and put forward the framework of software and hardware platform design based on PC+I/O software-based structural CNC system.
Motor Fault On-Line Diagnosis Based on Innovation Energy Detection
Authors: Long Jian Xiong
Published: July 2011

For the motor current noise signal, vibration signal, the phase current signal, a motor dynamic system model is established. A motor energy detection equation is introduced and constituted by an innovation series of these signal tested in the dynamic system, then the main factor analysis of the motor abnormal elements is presented by orthogonal decomposition, and the main factor distribution chart is described by decomposing the main failure elements to tow-dimensional observation vector. The motor fault can be detected on-line by using the main factor analysis, and then the failure factors can be identified with fault Mode.
Research of MH-Ni Battery State of Charge Estimation Based on Grey System Neural Network Model
Authors: Long Jian Xiong
Published: July 2011

In order to effectively achieve MH-Ni battery state of charge estimation, grey system neural network model is put forward to predict battery state of charge by using the parameters of battery pulse current response signal as input for grey system neural network. The state of charge is as the network output and the response parameters of the battery pulse current as the input. The results show that its prediction accuracy of the state of charge can be achieved to requirements of the electric vehicles in applications by this method to predict the state of charge.
Synthesis and Characterization of Zn-Ca-Mg-Al Hydrotacite-Like Compounds and its Application in the PVC
Authors: Li Long Feng , Gao Yuan , Zhang Mao Lin
Published: July 2011

Ca-Mg-Al hydrotalcite-like compounds (CaMgAl-HTLcs) were synthesized by a hydrothermal method, and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) techniques. The effects of the medium pH value, the molar ratio of the raw materials, the reaction temperature and the reaction time on the structure of CaMgAl-HTLcs were studied. The results showed that increasing treatment temperature and reaction time could improve the crystallinity and monodispersity of hydrotalcite-like compound particles. And well-defined CaMgAl-HTLcs could be prepared at a pH value of 10~11 with n(Zn+Mg+Ca):n(Al) =2. The products synthesized were applied to PVC to improve the thermal stability of PVC.
Tensile Deformation Behavior of 5A90 Al-Li Alloy Sheet at Elevated Temperature
Authors: Ma Gao Shan , Zhang Song Yang , Wang Han Ying , Wan Min
Published: July 2011

Uniaxial tensile deformation behavior of 5A90 aluminium-lithium alloy sheet is investigated in the hot forming with the temperature range of 200-450°C and strain rate range of 0.3×10-3-0.2×10-1s-1. It is found that the flow stress of 5A90 Al-Li alloy in uniaxial tension increase with increasing strain rate and decrease with increasing temperature, however, the tendency of total elongation is just the reverse, and the optimum forming temperature is 400°C. The strain rate sensitivity index (m-value) remarkably increases with increasing temperature for a given strain rate. It is shown that 5A90 Al-Li alloy sheet displays the sensitivity to the strain rate at elevated temperatures. For a given strain rate, the strain hardening index (n-value) decreases with increasing temperature, whereas the n-value increases above 350°C. The constitutive equation of stress, strain and strain rate for 5A90 Al-Li alloy at any temperature is obtained by fitting the experimental data, which gave a good flow stress model for the FEM simulation of hot forming.
Finite Element Simulation for Laser Ablation of Carbon Fiber Epoxy Composite
Authors: Zhang Jin Feng , Long Lian Chun
Published: July 2011

In order to predict the size and shape of the laser ablative hole, a 3D finite element model was developed to simulate the Nd:YAG laser ablation of carbon fiber epoxy composite. For given irradiation conditions, good agreement with experimental data relating to hole dimensions. The numerical results and experimental observations indicate that with the irradiation time increasing, the domain under investigation temperature raises rapidly and the further to the spot center, the smaller the temperature raises. After 0.093s the target surface temperature is higher than the critical temperature of composite, so the removal of the material on first composite layer occurs. It also can be observed that heat energy of the laser spread within the material and the isotherm ribbon, as well as crater border, is step-like.