bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Model for Constriction Resistance of Rough Contacts between Nominally Flat Surfaces
Authors: Peng Jun Feng , Hong Jun , Zhuang Yan
Published: October 2011

Thermal contact resistance plays an important role in many domains, such as microelectronics and nuclear reactors. This paper proposes a more comprehensive model for the prediction of constriction resistance of rough contact between nominally flat surfaces in vacuum. Firstly, a 3D geometrical asperity contact model is proposed based on the analysis of the profile of actual engineering surface. In this model, the contact is not simplified as a rough surface contacting with a perfectly smooth surface, but described as two rough surfaces. Oblique contact is considered and the effects of several parameters such as the shape of the asperity, the depth of interference, and the radial distance between the centerlines of the contacting asperities are investigated. Some mathematical derivations for constriction resistance are performed, and a series of numerical simulations are also carried out, covering a wide range of values of these parameters in practice applications. A comprehensive correlation for constriction resistance as a function of these parameters is finally obtained by nonlinear curve fitting, and it is validated through some comparisons and it can be used to predict more accurately the thermal contact resistance between rough surfaces.
Microwave-Assisted Extraction of Garlic Essential Oil from Garlic
Authors: Yang Li Min , Han Ling Ling , Yang Zhuo
Published: October 2011

Factors affecting microwave-assisted extraction of garlic essential oil from garlic were investigated experimentally. Suitable conditions for such extraction process were studied by single factor approach to improve the product yield. The product yield under the resultant suitable conditions can reach to 0.478% based on raw garlic cloves. The product yield for microwave-assisted extraction method is as 2.5 times as that for conventional solvent extraction approach.
Comparison Study on Microwave Absorbing Properties of SiC Absorbers
Authors: Liu Gu , Wang Liu Ying , Chen Gui Ming , Wei Wan Ning , Ge Chao Qun , Zhang Hu
Published: October 2011

In this paper, we have studied on the absorbing properties of three different types of SiC absorbers such as ultra-fine SiC, SiC whisker and nanometer SiC. Electromagnetic parameters of the three types of SiC were tested in the frequency range of 2~18GHz. Both the real and imaginary parts of complex permittivity of nanometer SiC are higher than that of others. The attenuation constant of nanometer SiC is higher than that of ultra-fine SiC and SiC whisker, increasing from 93.7 to 766.5 with increasing frequency. The minimum reflection loss of -5.53 dB was obtained at 9.72 GHz for the nanometer SiC. The nanometer SiC suggests a better capacity of dielectric loss in microwave range than that of ultra-fine SiC and SiC whisker.
Evaluation of the Steep Slope Stability Based on Theory of GPS Monitoring Analysis
Authors: Wang Run Sheng , Guo Li Wen
Published: October 2011

Because of rock slope,surface Mine is full of danger. In this paper, the monitoring system configuration and data processing are discussed in combination with GPS monitoring and date analysis of slope deformation in an Iron Mine in order to seize the rule of rock deformation and provid a more reliable basis for taking measures for control the rock Stability.The dynamic monitoring system and rock Stability evaluation method are developed so as to resolved the rock Stability in the surface mine that would be underground mining.Which can also provide for the design plan、data processing 、technical measures of the control the rock Stability and promote the continuable development of the Surface Mine.
Drug Release of a PH/Temperature Sensitive Core-Shelled Beads from Sodium Alginate and Poly(N-Acryloylglycinate)
Authors: Deng Kui Lin , Huang Chun Yuan , Zhang Peng Fei , Dong Li Rong , Li Dan Dan , Gao Ting , Wang Shu Liang , Jin Wen Hui
Published: October 2011

In this paper, a new pH/temperature sensitive hydrogel bead (HME) with core-shelled structure as a drug delivery system was prepared using N-acryloylglycinate and sodium alginate. In caffeine release studies, the effect of different pH value, temperature and the polymer content were evaluated, respectively. The results showed that 62.2% drug was released from the sensitive beads in pH 2.1 within 300 min, whereas 99.3% drug diffused into the medium in pH 7.4 at 37°C. The significantly higher release was observed at higher temperature than at lower temperature. In addition the release amount of drug was decreased with increasing polymer content. The release behaviors of caffeine suggested a feasibility of the beads as pH/thermo-controlled drug release carrier.
Effect of Sn on Corrosion Resistance of Mg-6Al-1.2Y-0.9Nd Alloy
Authors: Kang Hai Juan , Li Quan An , Zhou Wei , Zhang Qing
Published: October 2011

The effect of Sn addition on corrosion behavior of Mg-6Al-1.2Y-0.9Nd alloy in 3.5wt.% NaCl solution has been researched by static corrosion tests, corrosion morphologies observation, microstructure and corrosion scale analysis. The result shows that, with the content of Sn increasing, the corrosion rate decreases at first and then increases. When the addition of Sn is 1wt.%, the corrosion rate is the lowest and the corrosion resistance is improved obviously.
Physical Simulation of Grooved Axis Warm Surface Rolling
Authors: Zhou Xu Dong , Liu Xiang Ru
Published: October 2011

The experimental design and implementation, as well as the fatigue life test of the steel C45 grooved axis warm surface rolling, have been carried out in this paper. The focus of the experiment is to study the effect of the different amount of rolling reduction and surface temperature on the fatigue life of the specimen axis.The experimental specific condition is at different temperature 20°C, 100°C, 200°C and 300°C with surface rolling reduction 0.03 mm, 0.06mm, 0.10mm, and 0.15mm respectively. The simulation results showed that the warm surface rolling process can significantly improve the fatigue life of the specimen axis; and there exist a corresponding optimum rolling reduction, in this case the fatigue life of the specimen axis achieves maximum, at different warm rolling temperatures. Finally the preferred processing parameter at 300°C with 0.15mm surface rolling reduction is obtained. This study has certain reference value for steel C45 the crankshaft undercut surface rolling.
Study on Stability of High Embankments under Complicated Stress Conditions
Authors: Liu Sheng Chuan
Published: October 2011

Three-dimensional finite element analysis should be used in stability analysis of slope because it can overcome the short advantages of two-dimensional finite element and can simulate the complex topographic and geological conditions. Based on the large-scale triaxial shear test, the modified Duncan-Chang model is established. Based on strength reduction elasto-plastic finite element, stability of high fill embankment was studied with three-dimensional finite element method considering the complex terrain conditions. Study results suggest that plastic strain and displacement mutant of slip surface node can be a sign of slope instability as a whole. At the same time calculation of three-dimensional finite element also does not converge. Therefore, it can be slope instability criterion calculate whether the finite element static analysis converges or not. On the other hand, stability safety factor of high fill embankment under three-dimensional conditions is larger than that of two-dimensional conditions, which shows that boundary conditions of high fill embankment enhance its stability.
Checking Gypsum as Structural Material
Authors: Vegas Fernando , Mileto Camilla , Ivorra Salvador , Baeza Fco. Javier
Published: October 2011

Gypsum, relegated in contemporaneous architecture to a secondary, auxiliary or decorative role, has been traditionally employed in some parts of Spain for building structural pillars, floors, massive walls, mortars, etc. The authors have studied this gypsum in its several local forms, from its firing in the kiln to the building process in order to unveil the reasons for its excellent structural behaviour. With the first hypothesis, several strength tests with present commercial gypsum have been made at the laboratory. They confirm the extraordinary structural performance of the material, if only some conditions are respected during the building process.
Studies on MAaximum Hydrostatic Testing Pressure for New Pipeline
Authors: Chen Peng Chao , Zhang Hong , Wang Hong Ju
Published: October 2011

Hydrostatic testing is an important step in pipeline construction. This test ensures the integrity of newly-constructed pipelines. Testing pressures used by Chinese construction contractors are lower than that in foreign countries. Nowadays, higher testing pressure is considered safer for pipeline operation. But what is testing pressure we should apply? Basing on fracture mechanics theory, this paper addresses the effects of testing pressure on pipeline materials, and calculates the maximum safe testing pressure. Also, experiments validate the theoretic conclusions.
Research on Slope Deformation Regularity of the Badong Formation in the Three-Gorges Reservoir Area
Authors: Tang Hui Ming , Hu Xin Li , Xiong Cheng Ren
Published: October 2011

The Three-Gorges Reservoir area is characterized by widely distributed strata of Badong Formation, in which large size landslide and deep-reaching loose geological body are likely to form. Therefore, it is significant to reveal the mechanism and patterns of the large size landslide in Badong Formation for better understanding of the development of the nature of deformation and process of formation of the deep-reaching loose stratum slope. In this paper, the geological characteristics of the rock mass of the Badong Formation are concluded on the basis of systematic explanation of the space variation of the lithology combinations and space variation of structural deformation of the Badong Formation in the Three-Gorges Reservoir area. To demonstrate the basic law of long-term deformation of the Badong Formation slopes and the patterns of later stage reform and landslide evolution, the authors exemplify the Huangtupo landslide that is typical in the Badong Formation.
A New Nitriding Process of 4Cr5MoSiV1 for Extrusion Die
Authors: Lin Shen Yao , Zeng Jian Min , Chen Ping , Lin Zhuo Yi
Published: October 2011

Nitriding is one of the most efficient methods used to enhance the service life of aluminum extrusion dies. In this paper, a new nitriding process has been introduced that is characterized by that 4Cr5MoSiV1 steel, a typical material used for extrusion dies, was nitrided by using two-stage nitriding process. The microstructures of nitrided layer have been analyzed by means of optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD) and microhardness (MH). The results show that pre-heat treatment on the 4Cr5MoSiV1 steel extrusion die can be carried out under the condition of quenching at 1040 °C, double tempering at 600 °C and 560 °C for 2 hours each. Operating parameters of two-stage nitriding are set as follow: stage one, 520 °C for 6 hours, the flow rate of NH3of 0.6 m3/h; nitriding pressure of 453 Pa and stage two, 580 °C for 8 hours, the flow rate of NH3of 0.35 m3/h; nitriding pressure of 453 Pa.
Numerical Simulation of the Cold Expansion and Residual Stress Relaxation for Aluminum Alloy 7050
Authors: Guan Di , Sun Qin
Published: October 2011

Cold expansion is a well-known technique for improving the fatigue life of fastener holes in aeronautical structures by introducing a compressive residual stress field around them. In this paper, a 3-D finite element model is used to analyze the residual stress distribution and relaxation around an expanded hole for aluminum alloy 7050. The results reveal that the cutting process of split sleeve cold expansion and creep are main reason for residual stress relaxation in room temperature, which may limit the beneficial effects of cold expansion.
Microstructure of Flame-Spray Welded Ni-Based Alloy Coating and Base Metal
Authors: Li Xiao , Zhou Hao Bin , Chen Bing
Published: October 2011

One-step spray welding process was used to deposit Ni60 Ni-based self-fluxing alloy coating on 35CrMo wedge disc. According to different microstructure characters the cross-section of spray-welded specimen can be divided into three areas: spray welded coating, transition region and base metal. For the influence of welding thermo, base metal shows pearlite area, incomplete recrystallized area and original pearlite+ferrite area, the hardness of which is between 200HV to 165HV. The hardness of coating is about 865HV, which ensure good wear resistance. Because of the particles incomplete packing and the viscidity of melted metal, micro cavities formed near transition region and combine to form cavity chains, which will decrease the wear resistance and corrosion resistance of coating.
Study on Registering Accuracy and Precision in Test of Printing Press
Authors: Zhao Ji Bin , Li Xiu Li
Published: October 2011

The registering precision is one of the most important specifications in printing press. Many factors that may influence the registering precision including the construction of the printing press in design, the assembly precision in manufacturing stage, adjustment in process of operation, the wear and tear of the machine when it is in use, crawl of blanket and extension of sheet are all considered comprehensively. The mathematical models are built up to describe the register error of press. The algorithm of accuracy and precision of sheet-feeding and sheet-transferring is introduced. With the aid of image technology, the coordinates of marks can be obtained automatically, and the registering accuracy and precision can also be calculated.
Stability of a Supported Cylinder in Axial Flow
Authors: Jin Ji Duo , Li Ning
Published: October 2011

The stability of a supported cylinder subjected to axial flow is studied numerically. The dynamics of the cylinder is investigated with the numerical method applying the new nonlinear model in witch the nonlinear terms considered are the quadratic viscous force and the structural nonlinear force induced by the lateral motions of the cylinder. Using three-mode discretized equation, numerical simulations are carried out for the dynamical behavior of the cylinder. Some integration terms that appear in the discretization of the equation and can not be expressed in an analytical form are calculated using a numerical method. The results of numerical analysis show that at certain value of flow velocity the system loses stability by divergence and at a higher velocity the flutter around the zero equilibrium may occur. There is some region in witch three different motions (configurations) can take place at the same parameter values.
Temperature Distribution and Operating Efficiency in Rectangular Cold Crucible Directional Solidifying Ti46Al0.5W0.5Si Alloys
Authors: Yang Jie Ren , Chen Rui Run , Ding Hong Sheng , Guo Jing Jie , Su Yan Qing , Huang Feng , Fu Heng Zhi
Published: October 2011

This paper gives a detailed study of temperature distribution on Ti46Al0.5W0.5Si alloy directionally solidified by cold crucible. Based on experiment and numerical calculation, the heating process under different power was investigated, and the operating efficiency of cold crucible was roughly calculated. Further, the temperature field of Ti46Al0.5W0.5Si alloy under high power was numerically calculated, the finite element model predicted the temperature distribution at different moment. The results give a significance guide on cold crucible directional solidification.
Comprehensive Recycling of Construction Waste
Authors: Huang Jie Feng , Liang Qi Bin , Wang He , Xu Shu Yuan , Zhang Li Shan , Xing Yan
Published: October 2011

With China's urbanization process accelerated ceaselessly, construction developing rapidly, the great architectural waste discharge. At present, construction waste production but also has far exceeded the rate of domestic can bear. Meanwhile, the disposing mode, such as mechanical landfill and burned, resulting in huge waste of resources and environmental pollution. So how to efficiently processing and using reasonable construction wastes have become our country now faces a severe environmental and ecological problem. This paper discusses the causes, construction waste handling and processing components, the problems existing in the detailed analysis is introduced, and introduces some developed countries and regions with the application of construction waste disposal of the newest research achievement, and comparing and analyzing current construction waste comprehensive treatment of some problems existing in China, and finally puts forward some construction waste comprehensive reuse countermeasures.
Chemical Solidification Stress Calculation and Experiment of Concrete-Filled Steel Tube
Authors: Yang Zhi Fu , Meng Qing Yuan , Zhao Bing
Published: October 2011

Nowadays concrete-filled steel tube is widely used as a building structure. For concrete added with expanding agent, certain stresses will be produced during the solidification process. This is due to the fact that concrete solidification can not be conducted freely by the constraints of the steel tube. An algorithm of computational procedure for concrete chemical solidification stresses has been proposed, and an incremental calculation formula is derived in this paper. In addition, a testing facility has been designed and conducted to measure the circumferential strain during the solidification process. The calculation results are in good agreement with experimental data. The results show that the chemical solidification stress of concrete filled steel tube is not only related to the geometrical size of the structure and expanding rate of the concrete, but also related to the time history of expansion process. It is found that the stresses will become larger if the concrete expansion occurs later under the condition of identical expansion rates of the concretes.
The Application of Interval Analysis Method in the Stability Analysis
Authors: Hao Shan Shan , Xi Xin , Qu Shu Ying , Shi Wen Pu
Published: October 2011

This article introduces interval factors involved in material mechanics, and it also has many problems of interval parameters. Compressive rod stability design will be taken as an example to discuss interval analysis processing method; it explains not only the necessity for material mechanics and engineering design to lead into the interval analysis method, but also the specific application of it.
Investigation on Spb Method Based on Nondimensional Load Separation Principle for SEB and CT Specimens
Authors: Bao Chen , Cai Li Xun
Published: October 2011

In this work, a nondimensional load separation conforming to similarity principle was proposed. Based on this new principle, similarity simulation of the physical phenomenon between the prototype sample and the dimension-changed model sample can be implemented. Then, a modified separation parameter Spbmethod was developed, which can absolutely eliminate the effect of referencing blunt cracked specimen on the instantaneous crack length estimation of the sharp cracked specimen, and the forced blunt-corrected initial crack length and the final crack length are recommended as the calibration points for J-resistance curve estimation. Finally, the modified Spbmethod is successfully applied in the J-resistance curve estimation of two steels with CT and SEB specimens, respectively.
A Yield Criterion for Pressure-Sensitive Materials
Authors: Lu Chen Hua , Liu Bo , Sang Jian Bing , Qie Yan Hui , Wang Jing Yuan
Published: October 2011

Following the modified Gurson model in meso-mechanics, the models with spherical holes are established by the assumption which the matrix meets the two-parameter elliptic yield condition. The macroscopic stress expression which contains micro structure parameters and the material equation of yield surface are given by the upper bound theorem of plastic limit analysis. The parameters of the matrix material and damage(porosity) which impact on macroscopic yield surface equation are discussed. These works provide theory foundations for material damage and design.
The Application of Dynamic Compaction Techniques Combining Plastic Drainage Plate to Improve Soft Soil Foundations in a College
Authors: Chen Hai Yang , Liu Xiu Jun , Li Jian , Hou Xing Hua
Published: October 2011

After the research of detailed geological exploration report, as well as the selection and optimization of foundation processing programs, dynamic compaction method with reinforced plastic drainage board is chosen to achieve good results, shorten the duration and reduce the cost.
Numerical Simulation of the Collapse of Stepped Circular Tube Subjected to Oblique Load
Authors: Chen Dai Heng , Yang Lu
Published: October 2011

In this paper, the crushing behavior of stepped circular tubes under oblique compression is studied by finite element method (FEM) analysis. It is found that the stepped circular tubes exhibit good response to oblique load. The deformation of the tubes can be classified into stable and unstable modes depending on whether break point is observed in the compressive load curve. In the stable mode, the tube stays erect and absorbs compressive energy to the same extent as it absorbs axial load. However, in the unstable mode, the tube does not stay erect and can bear only much lower compressive load than that of axial crushing. The two deformation modes can be controlled by the geometry of the tube. The compressive load of the stepped tube under oblique crushing increases as the difference between the radius of the large tube and small tube decreases and as the total length of the tube increases. For geometries that take values near the boundary between the stable and unstable modes in the mode map, the stepped tubes exhibit maximum absorption efficiency. Moreover, the absorption efficiency of stepped tubes is proportional to thickness to about the 1.8 power.
Simplified Second Order Model of Reynolds Equation for Simulating the Ultra-Thin Air Bearing Film in Hard Disk Drivers
Authors: Ji Jia Dong , Shi Bao Jun , Yang Ting Yi , Wang Ji Yong
Published: October 2011

To more accurately simulate the pressure distribution of the ultra-thin air bearing film, Reynolds equation must be modified to account for the gas rarefaction effect. Starting from a widely used model of Reynolds equation, a new simplified second order model is proposed to simulate the ultra-thin air bearing film in hard disk drives. The new model of Reynolds equation possesses simpler mathematical form than that of the previous model. The new model is solved using a least square finite difference method and the resultant numerical results are compared with those of the previous model. The computational efficiencies of the new model and the previous model are also compared.
The Hydrodynamic Performance Prediction of Ship Hull with Propeller
Authors: Shen Hai Long , Abdelhak Gomri , Chen Qing Tong , Su Yu Min
Published: October 2011

This paper describes the hydrodynamic performance prediction of ship hull with propeller by using CFD techniques. As an attempt in investigating the flow features around ship hull equipped with a rotating propeller, open water test, resistance test, and self-propulsion test were conducted. The paper discusses also the applicability of different turbulence models which are used to predict the hydrodynamic performance of the propeller, the hull, and the interaction hull-propeller. The hydrodynamic performance prediction method was gotten and was validated. The computational results were validated against the existing experimental data.
Vibrational and Stochastic Resonance in FitzHugh-Nagumo Neural Model with Time-Delay and Colored Additive Noise
Authors: Zhou Yu Rong , He Zheng You
Published: October 2011

The vibrational resonance (VR) and stochastic resonance (SR) phenomena in time-delayed FitzHugh-Nagumo (FHN) neural model, driven by one high-frequency (HF) signal and one low-frequency (LF) signal, with coupled multiplicative and colored additive noise, is investigated. For the case that the frequency of the HF signal is much higher than that of the LF signal, under the adiabatic approximation condition, the expression of the signal-to-noise ratio (SNR) with respect to the LF signal is obtained. It is shown that, the SNR is a non-monotonous function of the amplitude and frequency of the HF signal. In addition, the SNR varies non-monotonically with increasing the intensities of the multiplicative and additive noise, with increasing the delayed-time as well as increasing the system parameters of the FHN model. The influence of the correlation time of the colored additive noise and the coupling strength between the multiplicative and additive noise on the SNR is discussed.
The Comparative Analysis on Muscles of Short and Long Track Speed Skating Athletes
Authors: Xia Jiao Yang
Published: October 2011

The knee and ankle muscle strength of excellent male skating athletes is measured and analyzed by Cybex isokinetic testing system. Based on the features of athletes’ muscles strength, the study aims to find if there are differences and shortages between long track and short track speed skating athletes and whether they can learn from each other in the training, then to make the further discussion on the event itself. The main conclusions are as follows: 1. In the index of maximum strength, the torque/BW features of knee and ankle of the short track athletes are more fit the law of skating event, while the long track athletes do good in low speed, but opposite in high speed. The long track skaters need to improve the strength in high speed. 2. In the index of flexor-extensor, both long and short-track are lower than the recommended values, especially the short track. The two groups need to improve the strength of flexor muscles and to keep balance and coordinate of knee muscles. 3. In the index of acceleration, the power values of long track skaters are higher than short track skater’s, except left extensor muscles. The left extensor muscles of long track skaters are lower than their right ones, and should improve the balance of both legs. The short track skaters need to improve the powers of left and right knees in all speeds.
Experimental Investigation on the Vortex-Induced Vibration of the Cylinders with Helical Strakes
Authors: Zhou Yang , Huang Wei Ping
Published: October 2011

The tests on the vortex-induced vibration (VIV) of the cylinders with different helical strakes were carried out in a uniform current. Both in-line and cross-flow responses were measured and a comprehensive analysis was made in order to understand the phenomenon of VIV mitigation by helical strake and find optimal design parameters, which are more effective for VIV mitigation, of helical strakes. The results show that the cross flow response of the cylinders with helical strakes could be reduced significantly and its in-line response may be enhanced severely. Therefore, much attention should be paid to the design of helical strake.
The Multi-Joint Measuring Arm’s Error Compensation Method Based on the Pose Configurations
Authors: Xiong Hui Yuan , Xu You , Zong Zhi Jian , Gao Qun
Published: October 2011

The multi-joint measuring arm’s measurement accuracy is associated with the measuring pose configuration. As the feature of the multi-joints arm with the adjacent joint orthogonal design, the triangle-based representation of measuring arm configuration was derived. Then measuring arm pose configuration simplified representation was presented. Based on the simplified representation, a polynomial model of comprehensive error compensation was proposed, and the calibration algorithm was derived.Tests confirmed the effectiveness of the method, which can effectively improve the single-point measurement accuracy.
A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on Pd Nanoparticles Modified Electrode
Authors: Zhuang Zhen Jing
Published: October 2011

Pd nanoparticles have been prepared on the surface of glassy carbon electrode (GCE) by electrochemical deposition method and applied for the nonenzymatic detection of H2O2. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to investigate the as-prepared Pd nanoparticles on the surface of GCE. The electrochemical properties of Pd nanoparticles modified GCE were also characterized by cyclic voltammetry and chronoamperometry. The results showed that Pd nanoparticles modified GCE had a favorable catalytic ability for the reduction of H2O2in PBS medium (pH=7.6). At an applied potential of -0.06 V, the nonenzymatic H2O2sensors produce high and reproducible sensitivity to H2O2with 52.45 μA/mmol۰dm–3. Linear responses were obtained over a concentration range from 0.15 mmol۰dm–3to 18 mmol۰dm–3with a detection limit of 25 μmol۰dm–3(S/N=3). Additionally, it exhibited a rapid response time (within 1s), which was much faster than some nonenzymatic H2O2sensors.
Hot Deformation Behavior of the 30%Mo/Cu-Al2O3 Composite Prepared by Vacuum Hot-Pressed Sintering
Authors: Liu Yong , Sun Yong Wei , Tian Bao Hong , Feng Jiang , Zhang Yi
Published: October 2011

Hot deformation behavior of the 30%Mo/Cu-Al2O3 composite was investigated by hot compression tests on Gleeble-1500D thermal simulator in the temperature ranges of 450~750°C and the strain rate ranges of 0.01~5s-1, as the total strain is 0.7. The results show that the peak stress increases with the decreased deformation temperature or the increased strain rate. Based on the true stress-strain curves, the established constitutive equation represents the high-temperature flow behavior of the composite, and the calculated flow stresses are in good agreement with the high- temperature deformation experimental results.
Microstructure and Properties of 31Mn2SiREB Cast Steel
Authors: Ren Feng Zhang , Mei Ya Li , Li Feng Jun , Cheng Jun Wei , Wang Yu Fei
Published: October 2011

Heat treatment process of 31Mn2SiREB cast steel used in crawler plates is directly quenching at 1050°C after casting. The reasonableness of the process needs to be surveyed. In this paper, the effect of quenching temperature on mechanical properties was studied, and the micro-area composition and micro-hardness at different quenching temperature were investigated. The results show that tensile strength and impact energy increase observably with the elevating of quenching temperature. With the increase of quenching temperature, the fluctuations of micro-hardness and chemical composition at different micro-areas become obviously small. This means that the relatively homogeneous structure and composition can be acquired in higher temperature. The as-cast microstructure is extremely uneven, so pre-treatment process of normalizing or diffusion annealing ought to be carried out before quenching treatment, and quenching temperature should not be too high.
Experimental Study on Cutting Forces in Turning Aluminum-Silicon Alloy ZL104
Authors: Yuan Yue Feng , Zhang Wen Ying , Chang Xing
Published: October 2011

Cutting force experiments in turning aluminum-silicon alloy ZL104 are carried out with cement carbide tool YG8. The influence of cutting parameters on cutting force is obtained based on single factor experiments. The results indicate that depth of cut and feed rate have great influence on cutting force while cutting speed provides just little impact.
The Establishment of a Prediction Model for Surface Roughness in Ultrasonic-Assisted Turning
Authors: Yang Ching Been , Deng Chyn Shu , Chiang Hsiu Lu
Published: October 2011

During experimentation, traditional Taguchi analysis often uses L18 or L27 orthogonal array, with a considerable number of test sequences for Run 18 or Run 27. Both are time-consuming and expensive. A progressive Taguchi-neural network model is proposed in this study, which combines the Taguchi method with a neural network construction, and can construct a prediction model for surface roughness in ultrasonic-assisted turning. According to the results, the Stage-1 initial-network, due to its limited number of network training examples, generates good predictive ability results for regions near Taguchi factor level points. For learning and training examples from regions farther out, prediction results are increasingly unreliable. Comparably, the Stage-3 precision-network generates the more reliable predictions for global regions.
Computer-Aided Front and Rear Wings Aerodynamic Design of a Formula SAE Racing Car
Authors: Chen Mei Nan , Tang Wen Hui , Yang Bo , Hu Xing Jun
Published: October 2011

The objective of this research is to design a set of front and rear wings that can help maximize the down-force to enhance the aerodynamic performance of 2011 Jilin University Formula SAE racing car in dynamic events. In this research, computational fluid dynamics analysis is used for the design of the front and rear wings. Based on a given vehicle body styling, twenty sets of front wing and rear wing profile are investigated, the influence of the endplate shape on the wing aerodynamic performance is also investigated, and one plan was chosen as final design, which is suitable for the vehicle at a relatively low speed (70km/h). The CFD analysis results show that the suitable front wing and rear wing will enhance the aerodynamic performance of the racing car significantly.
Stability Analysis for Pillars during the Process of Panel Mining Based on Dynamic Fuzzy Reliability
Authors: Yang Shi Jiao , Luo Hui , Dai Jian Yong , Wu Chang Zhen
Published: October 2011

Panel mining requires constructing lots of artificial pillars in underground metal mines. Along with the development of the mining process the stress-strain state of pillars changes constantly. Finite element numerical simulation with Midas/GTS software is used to analyze the stability of the pillar during the entire process of panel mining and consider randomness and fuzziness for material parameters of concrete and ore rock to get stress distribution in the pillar. In this paper, the performance function and equation of dynamic fuzzy reliability for a pillar in the whole mining process are established and are solved by a program developed with the MATLAB software. Applying the proposed theory and procedures to dynamic fuzzy reliability analysis and calculation of the pillar was set in panel mining under complex conditions in Zhao Tong Lead-Zinc mine. The results indicate that dynamic fuzzy reliability can better reflect the pillar stability during the entire process of panel mining and the proposed theory and procedures are effective in evaluating the dynamic fuzzy reliability.
Study on Pulsed Eddy Current Nondestructive Testing Technology for Pipeline Corrosion Defects Based on Finite Element Method
Authors: Liu Han Wu , Zhan Shan Ping , Du Yun Hui , Zhang Peng
Published: October 2011

According to the principle and the type of the oil pipeline corrosion, we use the square wave of wide spectrum, strong signal transmission capability and a certain duty ratio as the excitation source of the pulsed eddy current. The finite element analysis software ANSYS is used to establish a three-dimensional finite element model of the pipeline corrosion defects by applying the boundary conditions of square wave excitation to simulate the distributions of current and induced magnetic field in the pipeline under various defect volumes. It can solve the induced voltage variation with time on detection coil, and can accomplish the finite element analysis and the nondestructive testing about the pipeline internal corrosion defects with the insulation layer and the protection layer. The results of the study show: When there is no corrosion defect in the pipeline, the electric current in the pipeline is basically even distribution. The magnetic field is distributed for the symmetrical vortex shape from head to foot, and it has not obviously gather phenomenon. When there are some corrosion defects in the pipeline, the electric current forms partial symmetrical vortex shape in both sides of the corrosion defect, and it is obviously assembled in the defect place. The simulation results of the different size defects show that the maximum magnetic field strength and the maximum current value increase with the defect depth increasing, while the output voltage decreases with the defect depth increasing. By extracting the induced voltage signals on the detection coil in a certain excitation condition, the quantitative detection of the pipeline corrosion defects can be achieved.
Dynamics Modeling and Simulation of Collision and Impact Test Machine Based on Baby Carriages
Authors: Wang Zhi Ming , Zhu Chong Hui , Tang Dong Mei , Yuan Jing , Xu Xiao Chun
Published: October 2011

In order to solve problems and modify design deficiencies in safety testing of baby carriages, a new collision and impact test machine is designed. Force and movement are analyzed by physical modeling of the test machine. The use of virtual prototyping technology to simplify the testing machine model and velocity, acceleration parameters and energy loss diagrams of measured object are obtained by dynamic simulation of the test machine model. The analysis results are obtained by comparative simulation of group data which show error of the test machine on collision velocity and impact energy fully meet the requirements of domestic and international testing standards and much lower than error of traditional experimental methods. The experimental method is verified feasibility and advanced in theory and provides a theoretical basis for developing the test machine.
Research on Automatic and Rapid 3-D Modeling for Flow Field of a Control Valve
Authors: Zhang Yue Rong , Wang Yong , Li Cheng De
Published: October 2011

In the research of the flow field about a control valve in the method of CFD (Compute Fluid Dynamics), the process of 3-D molding is difficult for some reasons, the complex interior structure of valve, the requirement aimed to be different opening, etc. We obtain a method to accomplish 3-D modeling of flow field automatically and rapidly in this paper by Cavity Command, Component Configurations and Driven Dimension. It is verified that this method is valid to mesh molding and CFD experiment.
The Simulation Research on Pressure Control System of the High-Speed Train's Carriage
Authors: Hou Xiao Ming , Zhang Xing Juan
Published: October 2011

A kind of digital pressure control project is put forward to solve the problem of pressure fluctuation inside the carriage by using the experience of airplane's pressure control system. Based on the pressure difference monitored between the inside and outside of the carriage, the control signal is output to the actuator by the controller, according to the control program set in it, in order to stabilize the pressure in the carriage. After the mathematical models of the main parts of the control system are found, a mathematical model of the whole system is established. Fuzzy control technology is applied in the new control system. The fuzzy controller is designed by using the matlab software, and then the simulation system is constructed. It is proved practical by the simulation result.
Statistics Analysis of PCA-Based Sensor Fault Detection
Authors: Qiu Tian , Zhu Xiang
Published: October 2011

It is of importance to analyze relations between Hawkins' T2H statistic and process variables mean and variance. The formula of T2H statistic mean is derived, and its variation law with process variable mean and variance is investigated. Simulation data indicates that the variation law of T2H is similar to SPE. Changing of process variable mean and variance can both enlarge T2H, while process noise can make the statistic oscillating.
Security Analysis of Concast and Anycast Digital Signature
Authors: Liu Cheng Lian , Guo Yong Ning
Published: October 2011

In the above paper a conception has been proposed which is a variant of the ElGamal-type digital signature. It considers the problem of authentication in the concast and anycast communication model. This paper proposed an improvement of concast scheme and also given a forgery attack on the anycast scheme. The authors state signature scenario scheme as follows.
Effects of Different Angulation Placement of Mini-Implant in Orthodontic
Authors: Omar Aisyah , Ishak Muhammad Ikman , Harun Muhamad Noor , Sulaiman Eshamsul , Kasim Noor Hayaty Abu
Published: October 2011

Orthodontic is one of the treatments in dentistry field which concerned on malocclusion treatments such as improper bites, tooth irregularity and disproportionate jaw relationships. The mini-implant (OMI) is one of the components used in the orthodontic treatment, besides braces and spring. The application of OMI has been well accepted in orthodontic treatment. However, one of the main factors of OMI failures is the implant insertion procedure in which the clinician find it difficult to obtain the best angle to insert the OMI. Therefore, this study aims to evaluate stress in an OMI and bones using the finite element analysis (FEA) with variations of insertion angles and to identify their optimal angle for the implant placement. The three dimensional (3D) model of a left maxillary posterior bone section was constructed based on CT image dataset. That 3D model consists of cortical bone, cancellous bone, second premolar, first molar and second molar teeth. The 3D model of OMI was placed between root of second premolar and first molar teeth. The OMI was simulated with seven different angles of insertions: 30˚, 40˚, 50˚, 60˚, 70˚, 80˚ and 90˚. Within the seven different insertion angles, the results showed that the increase of insertion angle reduced the maximum equivalent von Mises stress in cortical bone, cancellous bone and OMI. Based on this FEA study, the optimal angle placement of OMI is when the implant positioned at vertical angle (90˚) to the bone surface.
Chinese Ecovillage Practice with Cradle to Cradle Design
Authors: Wang Guo Guang , Huang Qiao Lun , Yuan Jing Ya
Published: October 2011

China currently is undergoing an unprecedented urbanization process which is accompanied by a severe damage to the environment. Cradle to Cradle Design approach has been gaining increasing interest among industries, authorities and consumers over these years. Its compelling design principles make people believe that adopting it in village planning or city planning is a very promising solution to China’s urbanization. This paper not only illustrates the features of ecovilllage and the design principles of Cradle to Cradle Design but also investigate the situation of first high-profile Cradle to Cradle planning project in China.
Studies on Digital Shearography for Testing of Aircraft Composite Structures and Honeycomb-Based Specimen
Authors: Feng Hui Juan , Zhang Jian , Liu Xiang Kai
Published: October 2011

This paper reviews shearography and its applications for testing of aircraft composite structures and honeycomb-based specimen. Shearography is a laser-based interferometry in conjunction with the digital imaging processing technique for full-field measurement of surface deformation. It reveals defects in an object by looking for defect-induced deformation anomalies. It does not require special vibration isolation, and with the development of a small and mobile measuring device (portable inspection system), it can be employed easily in field/factory environments.
A Robust High Density 7T Subthreshold SRAM Bitcell with Partial Dynamic Threshold Voltage Connection Scheme
Authors: Yang Jun , Qiu Ming Qiang , Huang Kai , Bai Na
Published: October 2011

Combined with partial dynamic threshold MOSFET connection scheme, a high density 7T subthreshold SRAM bitcell operating at supply voltage of 200 mV is proposed in this paper. Dual write and single read ensures high read static noise margin of the SRAM bitcell without expense of writability degradation. The 7T SRAM exhibits robust efficiency, making the design less vulnerable to process variation. Compared to the referenced 6T and the 8T SRAM bitcell, the proposed bitcell has four aspects of improvement: (1) 5.1% and 6.1% larger hold margin, (2) 80.6% and 85.5% of standard deviation, (3) 50% and 18% reduction of area (at 200 mV), and (4) 16X and 32X bitcells per bitline. To our best knowledge, the area penalty of proposed SRAM is the smallest with robustness and functionality of subthreshold SRAM achieved.
Research on the Technology of Testing and Evaluation of the Existing Building Foundations
Authors: Zhang Zhen Shuan , Deng Yu , Fu Shi Feng
Published: October 2011

In this paper, some technologys are measured and studied with good applicability and reliability,such as static loading test technology,in situ sampling technology,shear wave velocity test technology,GPR testing technology,low strain dynamic testing and settlement observation technology. It can be popularized in engineering.
The Solution on the Gnaw Rail Problem of the Bridge Crane
Authors: Xu Hua , Zhong Guo An , Wen Qing Ming , Hai Zeng Ping
Published: October 2011

The paper introduces the running and the gnaw rail of the bridge crane and analyses the judgment and the reason of the gnaw rail. The control system of the automatic rectifying deviation solves the problem of the gnaw rail. The paper also illustrates its method, feature, function and principle, etc.
Study on Manufacturing Resource Data Management Model for Steel and Iron Enterprise
Authors: Bo Hong Guang , Chen Sheng Wu , Xu Deng Feng , Liu Xiao Bing
Published: October 2011

The information fusion of production、process and capacity is the key problem to coordinate and integrate enterprise manufacturing resource. For the feature of enterprise manufacturing resource, this article proposed the data management method of steel enterprise manufacturing resource which is based on the BOMR model, this method made the relational structure of "production-process-capacity" as the core, constructed data model and relationship matrix according to different stages of production. According to the result of application in enterprise, this method overcame the asymmetric information when traditional BOM、BOC used separately, provided data integrating framework for the management of steel enterprise resource.
Recycling Technology for Grinding Swarf: Application to Iron Powder for Disposable Body Warmer
Authors: Takagi Hitoshi , Miyazaki Takanobu , Tamatani Junji
Published: October 2011

The recycling of grinding swarf which is a typical industrial waste discharged from machining facilities for ball and/or roller bearings is studied. The grinding swarf is investigated whether it is possible to use as a raw material for commercial products such as a disposable body warmer. Since the major constituent of the disposable body warmer is fine iron powder, there is strong possibility that the grinding swarf can be used to make the disposable body warmer instead of the commercially available iron powder. The influence of the pretreatment conditions to the grinding swarf on various heat-generating characteristics of the disposable body warmer sample; such as average temperature and heating duration, is examined. It is shown that the heating behavior of the disposable body warmer made from the grinding swarf was comparable to that of commercial one.
The Performance of the Nodular Cast Iron Treated by Troostite Heat Treatment
Authors: Liu Ke Gao , Jiang Zhi Hao , Li Jing
Published: October 2011

The mechanical properties of the nodular cast iron treated by troostite heat treatment were investigated, which technologies are control-cooling, adjustment at medium temperature and isothermal transformation. The fracture morphology and the microstructure were observed by scanning electronic microscope. The experimental results show that, the microstructure and mechanical properties in surface of the pieces were nearly same as that in the core after processing. Remarkable sudden change spot was not observed. The microstructure and performance with good uniformity and continuity have high stability.