bluuebunny/crossref_metadata_2025 huggingface dataset:
Collar TEOS Integrity of Deep Trench DRAM Capacitor with a Vertical Parasitic NMOSFET
Authors: Wang Mu Chun , Yang Hsin Chia
Published: August 2011

An adequate measurement metrology to nondestructively verify the integrity of dielectric gap-fill in a deep trench (DT) capacitor of deep-submicron DRAM product was proposed. Because of the geometric structure in the DT capacitor, the vertical cylindrical electrode isolator approximately provides a parasitic NMOSFET. Through the electrical measurement, people can analyze these drain-to-source electrical characteristics. Some of most valuable device parameters, threshold voltage (Vt) and mobility (un), correlate to the interface integrity and the surface roughness between silicon substrate and gap-fill oxide (or liner oxide). In other words, as these values are obtained, the degradation level of this interface or gap-fill quality can be clarified. Indirectly, the charge storage quality of this capacitor, avoiding the leakage path, is able to be improved with the process modification.
A Blending Control Aircraft Assembly Quality Method Using Key Assembly Characteristic
Authors: Liu Ji Hong , Wang Tie Hua , Zou Cheng
Published: August 2011

Assembly quality control is the main problem concerned by assembly departments in aircraft industry. This paper discusses the key assembly characteristics (KACs) which are the critical dimension characteristics for assembly quality in details, and then proposes a mathematical method which consists of identification and blending control method (BCM) towards KACs. BCM includes tightening tolerance and compensation, which can quantitatively control the KACs determined by validating error stack-up. A demonstration is given to verify the validity of the proposed method by controlling the assembly quality of an aircraft vertical tail.
Design of Medical Wireless Sensor Network
Authors: Sun Ying , Ye Sheng Hua , Ye Ying
Published: August 2011

The paper presented the Medical Wireless Sensor Network model with combining battery energy, environment energy and human body energy to provide energy supply. Also, the paper discussed sensor node planning designed by means of ZigBee technology. After combining the application of Internet, it could not only carry out remote localization, but also ensure the accuracy, sensitivity and safety of close monitoring.
Processing Effect of Injection Molded Nanoparticle/Polymer Composites on their Resistivity
Authors: Wu Hai Hong , Cheng Yong Feng , Jiang Ai Yun , Zhang Bao Feng
Published: August 2011

In order to improve the application of nano-particles/polymer composite, we investigated the relationship between microstructures and electrical properties on injection molded composites made from carbon black(CB) particles mixed with polypropylene(PP). Standard tensile specimens were injected under different processing conditions, after which, the specimens were cut off along the surface to observe the microstructures at different positions of the moldings. The microstructures were observed with Scanning Electrical Microscope(SEM), and electrical properties were measured by using a two-terminal standard resistor under DC condition at room temperature. The results showed that CB nano-particles may form the best conductive path under the higher packing pressure combined higher injection pressure. If packing pressure is low, the resistivities at the skin zone loaded by high injection pressure are smaller than low injection pressure, but the resistivities increase at the sub-skin zone. We found that the sub-skin zone is a high resistivity district which would expand with higher injection pressure matched lower packing pressure. Contrast to the injection molded polymer whose microstructural orientation is stronger at the sub-skin zones, injection molded CB particles/polymer composites develop strong oriented microstructures at the core zones in stead of the skin or sub-skin zones due to CB particles’ migration.
Flow Stress Behavior of the Normalized and Tempered as-Cast 42CrMo Steel during Hot Deformation
Authors: Qi Hui Ping , Li Yong Tang , Fu Jia , Liu Zhi Qi
Published: August 2011

The purpose of this study is to find the hot deformation behavior of as-cast 42CrMo steel. The thermal simulation experiments of as-cast 42CrMo steel were done on the Gleeble-1500 thermo-mechanical simulation machine. The hot deformation behavior of as-cast 42CrMo steel was analyzed. The true stress-strain curves in hot deformation at different deformation temperature (850°C,950°C,1050°C,1150°C), different strain rate (0.05S-1, 0.5 S-1, 1 S-1,5 S-1) were obtained. The influence rules of the deformation temperature and strain rate on the curves were analyzed. The analysis shows that the true stress increases with increase of deformation temperature and decrease of stain rate. The hot deformation behavior of as-cast 42CrMo steel was compared with forged 42CrMo steel. The results show that the flow stress of as-cast 42CrMo steel during hot deformation was higher than that of the forged 42CrMo steel. Compared to the forged 42CrMo steel, the dynamic recrystallization in as-cast 42CrMo steel during hot deformation is more difficult to occur. The above conclusions have significant theoretical and practical meanings for the design of hot deformation process of as-cast 42CrMo steel.
Influence of Ultrasonic on the Microstructure and Properties of Electroless Plating Ni-Co-P Coating at Low Temperature
Authors: Sun Hua , Guo Xiao Fei , Liu Ke Gao , Ma Hong Fang , Feng Li Ming
Published: August 2011

By electron energy spectrometer,X-ray diffractometer,transmission elec-tron microscopy andmicro-hardometer,the depositing speed of electrolessNi-Co-P plating baths,chemical composition,crystal structure and microhardness of the alloy coatings were inspected and analyzed with ultrasonic and rare earth metalcerium intervening in electroless Ni-Co-P plating•The results show that the depositing speed of electroless Ni-Co-P plating isobviously increased under the effect of ultrasonic.The chemical compositions of electroless Ni-Co-P plating are changed，The XRD of coating has a diffuse sexual diffraction peak closing to typical amorphous structure.the obtained Ni-Co-P coating has more fine crystal grain, even and dense surface morphology. Its wear resistance and hardness have been improved obviously.
Adaptive Neuro-Fuzzy Inference System Modelling of Surface Roughness in High Speed Turning of AISI P 20 Tool Steel
Authors: Cui Bo Di
Published: August 2011

Accurate predictive modelling is an essential prerequisite for optimization and control of production in modern manufacturing environments. In this paper, an adaptive neuro-fuzzy inference system (ANFIS) model was developed to predict the surface roughness in high speed turning of AISI P 20 tool steel. Experiments were designed and performed to collect the training and testing data for the proposed model based on orthogonal array. For decreasing the complexity of the ANFIS structure, principal component analysis (PCA) was used to deal with the experimental data. The comparison between predictions and experimental data showed that the proposed method was both effective and efficient for modelling surface roughness.
3D Finite Element Analysis of Marine Diesel Engine Connecting Rod
Authors: Zheng Bin , Liu Yong Qi , Liu Rui Xiang , Meng Jian
Published: August 2011

In this paper, with the ANSYS, stress distribution and safety factor of marine diesel engine connecting rod were analyzed by using 3D finite element method. The results show that the position of maximum principal stress is transition location of small end and connecting rod shank at maximum stretch condition. The value of stress is 24.69 MPa in dangerous position. The position of maximum principal stress is transition location of small end and connecting rod shank at maximum stretch condition. The value of stress is 198.65 MPa in dangerous position. Safety factor is 2.51.
A Novel Silicon-Based Packaging Platform for High-Efficiency LED Modules
Authors: Wang Cong , Lee Won Sang , Kim Nam Young
Published: August 2011

A novel silicon-based packaging platform with the electroplated-based reflector and the electrode- guided interconnections is developed for the packaging component of a high-luminosity and high-efficiency multi-chip light-emitting diode (LED) module, which is patterned on a new type of insulating layer that consists of nanoporous anodized aluminum oxide (AAO) layer and plasma- enhanced chemical vapor deposition (PECVD) deposited silicon dioxide (SiO2) on a doped silicon substrate. The reflector and the electrical interconnections are successfully fabricated by using the electroplating method in the same body. In order to obtain the benefits of high efficiency LED modules, the requirements concerning thermal management and photomechanical layout have to be met. In this paper, we will discuss a novel fabrication method in LED module packaging platform, and then describe the thin layer of electroplated Cu/Ni/Au in order to reduce thermal resistance and to increase thermal diffusion efficiency. The heat generated by the LED chips is dissipated directly to the silicon body through the metal-plated platform, and truly excellent heat dissipation characteristics are observed. We demonstrate 987 lm 8 W-level cool-white light (5000 K, 16 V, 110 lm/W, CRI = 77) emission for 570 µm × 230 µm-chip LEDs at 600 mA operation.
Instantaneous Cutting Force Model in High-Speed Milling Process with Gyroscopic Effect
Authors: Zhou Hong Liang , Tang Wei Xiao , Song Qing Hua , Ju Hua Wei
Published: August 2011

High-speed milling (HSM) has advantages in high productivity high precision and low production cost. Thus it can be widely used in the manufacture industry. However, when the speed of spindle-tool reaches a higher speed range, the gyroscopic effect will become an important part of its stable milling. In this paper, a dynamics model of HSM system was proposed considering the influence of gyroscopic moment due to high rotating speed of end milling. Finite element model (FEM) is used to model the dynamics of a spindle-milling system. It obtains the trajectory of central point in face milling with considering gyroscopic effects through the dynamics model at high speeds. Then the cutting force model will be corrected by the trajectory of face milling. So it can provide a basis for stability prediction of high speed milling.
Experiments and Simulation of Elastic-Plastic Deformation in Thin Wall Part Milling
Authors: Tang Ai Jun , Liu Zhan Qiang
Published: August 2011

Aircraft components are mostly made by aluminum alloy as thin wall types. These parts are usually end milled to required thicknesses and tight tolerances in specific areas. The thin wall parts are difficult to machine because they are easy to vibrate and deformed due to their lower rigidity. This paper proposes a new elastic-plastic deformation model which is suitable for prediction of machining deformations of end milled thin wall parts. The theoretical deformation model is established on the basis of the equations of Von Kármán. The effect of bending springback is also taken into account. The part deformations are simulated using FE analysis and Matlab. Milling experiments on a CNC machining center are performed. The experimental results show that the deformations for the peripheral milling of thin wall parts can be captured with very high accuracy using the proposed elastic-plastic deformation prediction model.
A Study on Storing Process of Thermoforming Using Finite Difference Method
Authors: Li Zhen Zhe , Shen Gui Ying , Wang Xiao Qian , Li Mei Qin , Shen Yun De
Published: August 2011

Obtaining a uniform thickness of the final product using thermoforming is difficult, and the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the time-dependent temperature distribution of the total sheets in the storing process was studied because the temperature after the storing process is the initial temperature of the preheating process. An analysis code for simulating the storing process was developed under the condition that the thermal conductivity caused by contact resistance between sheets was assumed as a large value. In this study, the number of sheets in the storing room was adjusted for finding out the effect of it. The analysis results show that maximum temperature difference between sheets was significantly different when adjusting the number of sheets in the storing room. The temperature distribution of the total sheets and the method for analysis in this study will be used to optimize the storing process for higher quality of final products.
Experimental Study on Material Removal Rate for Engineering Ceramics Machining with Micro-Detonation of Striking Arc
Authors: Zhang Bao Guo , Tian Xin Li , Lin Ke Ling , Tang Xiu Jian , Mao Ya Tao
Published: August 2011

The material removal rate (MRR) of micro-detonation of striking arc machining (MDSAM) is studied. The orthogonal experimental design and regression analysis method are employed to build the empirical model and the influencing laws of processing parameters on impact force are educed. Experimental results show that the material removal rate decreases with the increment of working distance and increases with the growth of working current, working gas pressure and pulse width. The exponential type empirical model with feature of simple and reliable consists with experiment results well. The research can offer an important reference for the predication and control of material removal rate in the process of micro-detonation machining of striking arc.
Study on Mechanical Mechanism of ARB Process Based on Randomness
Authors: Zhang Guo Zhi , Fu Jun Jing
Published: August 2011

The process control mechanism of ARB(accumulative roll bonding) process was studied. Based on micro-plastic theory, the principal stress method of macro-plastic theory and probability theory, theoretical models of rolling force and its standard deviation calculation were established. Moreover, shear deformation was analyzed with the finite element method and the finite element model established was verified through comparing with the experiment. Furthermore, through calculating the rolling force of ARB process of the typical parameters, roll force variation of every cycle was obtained and the theoretical model was verified through comparing with the results of the finite element method. The study in the paper provides analysis method and theory foundation for process control and manufacturing of ARB process.
Application of Multi-Layer Composite Membrane in Tricone Bit Bearing
Authors: Qiu Ya Ling , Li Shi Bin , He Wei , Han Chuan Jun
Published: August 2011

Composite membranes of TiN, WC/C and TiAlN+WC are successfully prepared by means of magnetron sputtering. An analysis of the membranes’ hardness, surface topography and chemical composition indicates that the composite membrane have a greater hardness, and are compact in structure and uniform in texture. A abrasion test is conducted by applying the three membranes respectively to tricone bit bearings, and then a comparison made between them and non-membrane tricone bit bearing leads to the finding that tricone bit bearing with TiAlN+WC/C composite membrane has the highest abrasion resistance, with a dramatic increase of 30%~40%.
Numerical Analysis of the Workpiece Velocity in Electromagnetic Forming Process
Authors: Qiu Li , Lv Yi Liang , Jiang Cheng Xi , Han Xiao Tao , Li Liang
Published: August 2011

The effect of the motional electromagnetic force in the electromagnetic forming circuit on the workpiece velocity is analyzed. The differential equations of unconsidering and considering the motional electromagnetic force in the electromagnetic forming circuit are solved numerically. The results without considering the motional electromagnetic force are unavailable because they violate the law of conservation of energy, while the results with considering the motional electromagnetic force can accurately reflect the electromagnetic forming process. Furthermore, it is found that the electrical energy transforms into the kinetic energy due to the motional electromagnetic force.
Theoretical Analysis of Blood Alcohol Detection Based on Raman Spectroscopy
Authors: Li Yan , Wang Sheng , Wang Xiao Lei , Ma Wen Kui , Liu Jun
Published: August 2011

This paper introduces an analysis technology in detecting the alcohol content in human blood after drunken that bases on reflectionof Raman spectroscopy. This is a fast, non-contact, health and safety technology which take advantage of the human skin. The technology has a broad application in rapid detection of alcohol content in human blood.
Stainless Steel Lining High Pressure Reactors Were Tested and Manufactured by Hydraulic Pressure Expanding Method
Authors: Chen Hai Hui
Published: August 2011

New hydraulic bulge method and estimated conjoint results were explored. The equipment’s overall water pressure test is developed to get lining bulge and plastic deformation, to eliminate the gap between lining and shell. Integrated effect was estimated by measured layer gap, stress and strain through hydraulic bulge and pressure increase test. Test results show that: although the preliminary gap is not uniform, even 14~16 mm at some points, but the remnant is only 0.6~0.9mm after hydraulic bulge; cylinder always keeps elastic during the pressure increase test, and the linearity between cylinder strain and initial pressure is more than 0.99 after hydraulic pressure expanding treated; Lower temperature annealing of sheath did not have negatively affect on conjoint effect. It is a new technology with simplicity, safety, low production cost, and no pollution, which will create a new way of metal compound forming.
Study on the Formability and its Geometric Factors of Seamed Tube Hydroforming
Authors: Chen Xian Feng , Yu Zhong Qi , Li Shu Hui
Published: August 2011

Forming limit curve (FLC) is an important tool for assessing formability of steel metal. It is commonly obtained from experiment, theoretical calculation and finite element method (FEM) simulation. In this study, the FLC of a seamed tube hydroforming is established by combining the failure criterion of strain increment ratio and FEM simulation. The numerical method is verified by tube bulge tests. Then the sensitivity studies are carried out to evaluate the effect of the geometrical features of seamed tube on its formability by numerical approach. Results show that the changes of the formability with the geometrical features of a seamed tube.
Surface Effect Mechanism Analysis for Vibrational Rotary Forging
Authors: Zhang Rong Hai , Zhu Ning Yuan , Cai Gai Pin
Published: August 2011

As a contact of vibrational rotary forging is highly nonlinear, the contact area and boundary between rotary toolhead and workpiece had more accurate calculation, made the contact boundary more tally with the actual situation. For a surface effect is of complexity for vibrational rotary forging, a vibrational rotary forging visco-elasticity plasticity model was built, and the visco-elasticity spatial matrix and the visco-plasticity spatial matrix were derived by the generalized Hooke's law in elasticity theory and the increase theory in mechanics of plasticity, then by the finite element founction of MATLAB for the surface effect analyzed during the vibrational rotary forging deformation, it is shown as blow: the surface effect should be appeared with high frequency vibration or low frequency vibration, but there are some conditions for surface effect produced during plastic process, and then the hypothesis that the friction vector is reversal of deformation load, and it is benefit to deformation process during the part of time in vibration period is validated.
Preliminary Study on Prediction Model of Forming Tubular Bulge Height for a Thick-Plate
Authors: Liu Dan , Xiao Xiao Ting , Liao Yi Juan , Zhang Zheng Rong
Published: August 2011

To form the thick-plate with the tubular bulge, the backward and forward extrusion and punch process is proposed. The thickness of sheet metal, the inner diameter of tubular bulge, the diameter of punch-die, the forward extrusion depth and other process parameters are set by orthogonal regression design method and these groups of values are used respectively to simulate the combined extruding and punching process by the plastic analysis software DEFORM3D. And then, the linear regression equation is obtained between the bulge height and process parameters. The results indicate that the main factors affecting the bulge height are the thickness of sheet metal and diameter of punch-die within a certain range. However, the inner diameter of tubular bulge and the forward extrusion depth have a little contribute to bulge height. Also, the reliability of linear regression equation is not fine and the prediction model of tubular bulge needs to a more in-depth study.
Kinematics Analysis and Numerical Method for Multi-Link Suspension
Authors: Lu Mo Wu , Zhao Wei Qiang
Published: August 2011

This paper presents a numerical method for kinematics analysis of Multi-link suspension based on displacement matrix method. A mathematical model for kinematics analysis of multi-link suspension is established and the kinematical properties of multi-link suspension are analyzed using this method. The numerical method for solving this problem is discussed and the relevant program is developed. This method simplifies the solving process of kinematics properties analysis of multi-link suspension and is efficient especially for computer-based solving process.
Extraction of Niobium from the Bayan Obo Tailings by “Flotation—Microwave Magnetic Roasting—Magnetic Separation”
Authors: Wang Lei , Li Jie , Li Bao Wei , Wang Jun
Published: August 2011

In this paper, the method of “floatation—microwave magnetic roasting—low intensity magnetic separation” which aims to utilize the iron and Nb mineral in the Bayan Obo tailings was investigated. The results show that the method of “floatation—microwave magnetic roasting—magnetic separation” is effective and simple, and the recovery of iron and Nb in the whole process is up to 80% and 68% respectively. The step of microwave magnetic roasting is researched carefully, and the best magnetic roasting result is obtained at 650°C, and the roasting time is 10min.The best result of magnetic separation is obtained at the magnetic intensity of 220KA/m. Iron ore concentrate separated by magnetic separation can be used for iron making directly because the grade can reach about 62~64.4%. And the grade of Nb can reach up to 2.16%.
Development of a Novel Deployment Hinge Mechanism for a Spacecraft Using Axiomatic Design
Authors: Jeong Ju Won , Yoo Young Ik , Lee Jung Ju , Lim Jae Hyuk , Kim Kyung Won , Hwang Do Soon
Published: August 2011

This paper presents a novel hinge mechanism for deployment of spacecraft subsystems such as antennas, solar arrays. By using Axiomatic design theory, the conceptual design of the hinge mechanism is suggested, which has not only high deployed stiffness and low deployment shock but also does not require lubrication and accurate fabrication. That is, optimization of deployment torque and maximization of the deployed stiffness can be possible since this suggested hinge mechanism is decoupled design. And the suggested hinge mechanism is fabricated and tested to evaluate the feasibility. Quasi-static analysis is performed to optimize deployment torque for low deployment shock by using FEM. Also, the bending stiffness is measured by 4 point bending test.
Simultaneous Application of Coda Waves Interferometry (CWI) and Nonlinear Resonance (NR) to Detect Damage in Polymer Concrete
Authors: Toumi Souad , Bentahar Mourad , Mechri Charfeddine , Boubenider Fouad , El Guerjouma Rachid
Published: August 2011

In this study, we present the characterisation of damage in polymer concrete using coda waves interferometry (CWI). The latter takes into account the multi-scattered acoustic waves, whose travelling distances are considerably longer than the one corresponding to the direct wave (emitter-receiver direct distance). Experimentally, we prove that CWI is not always appropriate to detect damage. Therefore, we propose an original approach through which the interaction CWI with damage is optimised. This is done using nonlinear resonance (NR) method, where bending modes are excited, at the time when acoustic waves are multi-scattered. Experiments show an important increase in the sensitivity to damage with interesting perspectives in terms of damage location and characterisation.
Study on the Relationships between Edge Distance and the Failure Process of Edge Chipping for Engineering Ceramics
Authors: Tang Xiu Jian , Tian Xin Li , Zhang Bao Guo , Lin Keling Lin
Published: August 2011

Edge distance is the main factor inducing edge chipping. An edge chipping experiment is designed to study the relationships between edge distance and the edge chipping from the aspect of fracture process, the load-displacement curves and AE signals are documented. The results show that the fracture processes of edge chipping at different edge distances are similar and could be divided into four stages, AE signals could reflect the fracture process features of edge chipping. As edge distance increases, the displacements of indenter and critical loads would increase correspondingly, while the peak values of count and duration would decrease. The critical edge distance for Al2O3 is about 0.75mm; the displacements of indenter would keep invariable, while the peak values of count and duration would get to the minimum.
Seam Tracking Monitoring Based on Keyhole Features during High-Power Fiber Laser Welding
Authors: Gao Xiang Dong , Mo Ling , Katayama Seiji
Published: August 2011

Seam tracking is an important field to obtain good welding quality. During the high-power fiber laser welding, the laser beam focus must be controlled to track the welding seam accurately. A method of detecting the offset between the laser beam focus and the welding seam based on analyzing the keyhole features was researched during high-power fiber laser butt-joint welding of Type 304 austenitic stainless steel plates at a continuous wave fiber laser power of 10 kW. The joint gap width was less than 0.1mm. An infrared sensitive high speed camera was used to capture the thermal images of a molten pool in welding process. Two parameters called the keyhole centroid and keyhole shape were defined as the eigenvalues of seam tracking offset to determine the offset between the laser beam focus and the desired welding seam. The welding experiments confirmed that the offset between the laser beam focus and the welding seam could be monitored and estimated by the keyhole centroid and keyhole shape parameters effectively.
Elucidation of Welding Stability Based on Keyhole Configuration during High-Power Fiber Laser Welding
Authors: Gao Xiang Dong , Wen Qian , Katayama Seiji
Published: August 2011

During deep penetration laser welding, a keyhole is formed in the molten pool due to the intense recoil pressure of evaporation. The formation of the keyhole leads to a deep penetration weld with a high aspect ratio and this is the most advantageous feature of welding by high-energy-density beams. The configuration and characteristics of a keyhole are related to the welding stability. In a fiber laser butt-joint welding of Type 304 austenitic stainless steel plate with a high power 10 kW continuous wave fiber laser, an infrared sensitive high-speed video camera was used to capture the dynamic images of the molten pools. The configurations of a keyhole were analyzed through image processing techniques such as median filtering, wiener filtering and gray level threshold segmentation to obtain the edge of a keyhole. The width and the area of a keyhole were defined as the keyhole characteristic parameters, and the deviation between the laser beam and weld center as a parameter reflecting the welding stability. By analyzing the change of the keyhole characteristic parameters during welding process, it was found that these parameters were related to the welding stability. Welding experimental results and analysis of the keyhole characteristic parameters confirmed that the welding stability could be monitored and distinguished by a keyhole configuration during high-power fiber laser welding.
Progressive Failure Study of Discrete-Source Damage in Stiffened Composite Panels
Authors: Liang Li , Jia Pu Rong , Jiao Gui Qiong
Published: August 2011

In this paper experimental and FEA methods were used to study the damage propagation and failure properties of stiffened composite panels with discrete-source damage. The influence of discrete-source damage on residual strength of the composite panel was also investigated. The research results indicated that notched composite panel was suitable to simulate the damage property of stiffened composite panel with discrete-source damage. It has showed that there is high strain concentration at the notch end. And break-through of the stringer can make the load path changed. Based on different failure criteria, FEA method with progressive failure procedure was used to simulate the damage progression and failure procedure of the notched stiffened composite panel effectively. The analytical result was in good correspondence with the experimental data.
Effect of Working Current on Microstructure and Properties of Cylinder Hardened by Plasma Beam at Junction of the Hardening Traces
Authors: Yang Li , Qiang Ying Huai , Chen Fu Shan , Gao Yang , Zhong Yun Tian
Published: August 2011

To improve wear resistance and service life of boron cast iron cylinder, plasma beam hardening on surface is adopted.Scanning electron microscope,X-ray diffractometer and micro-hardness tester is used to analyze the effect of working current on the structure and properties of plasma beam hardening layer at the junction of the hardening traces. The results show that the microstructure of hardening layer at the junction is hidden acicular martensite, retained austenite and flake graphite. With the increase of working current, the content of retained austenite decreases, the hardness and depth of the hardening layer increases. The highest hardness is not achieved at the surface of hardening layer but at the second-surface layer which has a certain distance to the surface. The uneven distribution of hardness in hardening layer leads to large gradient at the both sides of the highest hardness and the gradient decreases with the increase of working current.
Research on Measurement Method of Oil-Water Interface Based on Oscillation Frequency
Authors: Hou Pei Guo , Xiao Xiang Zheng , Wang Zhong Dong
Published: August 2011

At the view of the present situation of the oil-water interface measurement, all sorts of measurement method can not eliminate the interference of temperature and hang oil. In order to control water ratio of purification oil at the output, simple interface detector cannot have satisfy the actual needs. A key contribution of this paper is to propose a solution based on a new type of sensor head and a test of new solution to the problem of capacitive sensing at high water ratio. A LC oscillation circuits is used to detect the variation of capacitance, overcoming the influence of the hang oil and the temperature.
Composition Control of Palladium-Sliver Alloy for Optical Fiber Hydrogen Sensor
Authors: Cui Lu Jun , Zhang Gang , Shang Hui Chao , Chen You Ping
Published: August 2011

The present work investigates diffusivity of hydrogen (H) in palladium-silver (Pd/Ag) over 300～1100K temperature range for Pd100-xAgx, X=0%～40% by using the Sievert Law. The silver in the Pd/Ag alloy has significantly higher diffusion as compared to pure Pd for hydrogen sensor, the addition of Ag reduces the critical temperature of α→Β phase transformations and also increases the solubility of H, and provides longer operational lifetime for hydrogen sensor. It was found that the diffusion coefficient of H in Pd/Ag alloy decreases with increasing Ag and with increasing temperature, the calculated diffusion coefficient of H in the Pd/Ag alloys were found to have a maximum at 24%～25% Ag.
Study on Monitoring the Dynamics Characters of Wind Turbine Tower
Authors: Shan Guang Kun , Tang De Yao , Zeng Cheng Zhi , Wang Ying Bo
Published: August 2011

Steady operation was one of the main objectives of wind turbine controlling. Online monitoring and fault diagnosis system had been installed on the wind turbine, the characters of system natural frequency were obtained by comparing collecting datum in site with theory analysis result. Wind turbine rotation speed should avoid [8.4r/min,10r/min] base on the characters to guarantee no resonance and avoid severe vibration. Such realizes wind turbine steady operation.
Design of Air-Tight Property Detector for Gas Meter Based on C8051F350 MCU
Authors: Jin Zhong Jun , Xiao Yan Ping , Mao Qian Min
Published: August 2011

With the natural gas widely used in the modern industry and daily life, gas safety issues become prominent. An air-tight property detector based on the principle of direct pressure with the C8051F350 MCU as the core is designed in this paper. It is controlled by the main and auxiliary systems in the form of hierarchical, and it is more flexible in detecting. The pressure is measured by the high accuracy differential pressure transmitter and the 24-bit A/D converter is used to deal with the small signals. The temperature compensation algorithm is introduced to improve the detection accuracy. As the uncertainty analysis shows that the experimental data meet the requirements.
An Iterative Learning Approach for Freeway Traffic Density Control
Authors: Liang Xin Rong , Wu Xiao Yan , Li Jian Ye
Published: August 2011

In this work, we apply iterative learning method to address the traffic density control problem in a macroscopic level freeway environment with ramp metering. The second-order traffic flow model is firstly formulated. Then traffic density is selected as the control variable in place of traffic occupancy. Based on the traffic flow model and in conjunction with nonlinear feedback theory, an iterative learning based traffic density controller is designed. Finally, the iterative learning based feedback controller is simulated in Matlab software. Simulation results show that this method has good dynamic and steady-state performance, and can achieve an almost perfect tracking performance.
A Novel Two-Level Instruction Issue Window Based on VLIW Architecture
Authors: Yang Hui , Chen Shu Ming , Wu Tie Bin
Published: August 2011

Instruction compression technique overcomes the drawbacks of traditional VLIW architectures with low density in the instruction cache. However, the separated long instruction word was arranged into two cache line. It comes to be a bottleneck problem for VLIW architecture processor performance because these split long instruction word can not be fetched and issued simultaneously. A novel two-level instruction issue window mechanism is proposed in this paper. It solves the instruction fetch and issue problem in separating instruction words. It provides more effective and continuous instruction flow, and stores one iteration of the loop body to support software pipeline technique, which improves VLIW DSP processor performance effectively. Proposed machanism was synthesized to evaluate its overall costs, and the performance speedup result for DSP/IMG library bencharks using the cycle accurate simulator are presented.
Testing System Design for Multi-Circuit Gear Pump
Authors: Sun Li , Yin Zhao Qin , Yu Xiao Yang , Zou Guang Wen
Published: August 2011

Multi-circuit gear pump working performance cannot be affected by load, and it outputs the same amount of oil in every port, which can provide static pressure supporting for the guide ways of machine tool. The test schematic is designed with the destination of testing multi-circuit gear pump hydraulic performance. Test equipment and hydraulic oil are selected scientifically and reasonably based on multi-circuit gear pump performance parameters which have been designed, and then hydraulic system is installed in order to execute performance testing.
The Processing Way of Pipeline Vibration Signal Based on Wavelet Transform
Authors: Shen Ji Chen , Zhao Shi Rong , Chen Jing Min
Published: August 2011

The vibration phenomenon of pipeline for conveying liquid and gas is very common. Based on the feature of pipeline vibration and multi-resolution of wavelet, this paper has mainly simulated the vibration signal of pipeline and made muti-scale analysis of the signal. At the same time, this paper points out that the selected frequency band which causes the vibration can be found out, by using frequency spectrum analysis of pipeline vibration signal, combined with Fast Fourier Transform (FFT).So this paper shows that the processing way of pipeline vibration signal based on wavelet transform is available.
Coupled Electrostatic-Structures-Fluidic Analysis of a Nozzle/Diffuser Diaphragm Micropump
Authors: Dong Jin Xin , Lin Xie Zhao , Ying Ji
Published: August 2011

Micropump is the key component in the micro total analytical system. The major technical impediment in improving the performance of this micro-device lies in the lack of understanding the physical phenomena and their interactions of electric, mechanical, and fluidic fields for performing their intended functions. Because of the complexity of the micropump, the full coupled numerical analysis is extremely needed. This paper presents for the results of such fully coupled simulations. CFDRC® was used for the transient analysis of an electrostatically actuated micropump. The results show that the dynamic characteristics of fluid in the micropump and the vibration of flexible diaphragm are highly interactive each other. The flow rectification of the nozzle/diffuser will work only after the pressure difference between the two ends of valve have reached at a critical value. In the pump chamber, the fluidic press distribution almost independent of the space variation. Due to the increasing demands for accuracy, the nonlinear features of viscous loss of the fluid can no longer be neglected or simplified, but have to be taken into account in detail.
Effect of Shot Blasting on Oxidation of TP304 Austenitic Stainless Steel in Steam
Authors: Wang Zhi Wu , Lei Yan , Wang Wei , Wu Yi Wei , Wang Jie
Published: August 2011

In this research, TP304 was treated by shot blasting under the pressure of 0.65MPa. The stainless steel shots used in the shot blasting experiment were in different sizes, separately with diameter 0.6mm and 1.2mm. To investigate the effect of shot blasting on the oxidation resistance behavior, steam oxidation experiments have been conducted to both original and shot blasting treating TP304s in 650°C and 25MPa. Then oxidation kinetics curve of each sample was measured by discontinuous weight method, morphology of oxide film was observed through SEM(scanning electron microscope), the component of the oxidation was measured by XRD(X-ray Diffraction), and the variation of Cr content in the oxide film was analyzed by EDS(energy-dispersive X-ray spectroscopy). According to the results, Oxidation kinetics curve in high temperature and pressure, expressed in original and shot blasting treating TP304s, both follow the principle of quasi-parabola and shot blasting can largely enhance TP304’s steam oxidation resistance in high temperature and pressure.
Body Type Classification and Increment Analysis
Authors: Jing Xiao Ning , Li Xiao Jiu
Published: August 2011

With the social mass production of garment industry, the same style clothing requires organizing production in various specifications or size series to meet the different needs of consumers. Fast, accurate and flexible automatic grading technology has become the research hotspot, and the scientific size table is the basis of this technology. This study collects the size data of 251 female college students. Then make the body type classification and gain the size table of intermediate type and the increment of each body type. This study provide the basis for MTM automatically parameter table of young female university students to establish a pattern grading system.
Microstructure Simulation and Experimental Research of as-Cast 42CrMo Steel during Quenching Process
Authors: Fu Jia , Li Yong Tang , Qi Hui Ping
Published: August 2011

The CCT curve and TTT curve of as-cast 42CrMo steel were precisely simulated by using JmatPro software. The quenching process(which is as follow: quenching at 860°C by AQ251 quenching liquid and cooling to 200°C) was given by analysizing the CCT curve. The quenching microstructure, hot-stress field and hardness after quenching were simulated by using the Deform-HT module The results were obtained as follows:(1)The microstructure of the materials is martensite+bottom bainite at the surface and pearlite+ferrite at the centure.(2)The surface hardness and central hardness were separately 51.3 and 28.5 HRC. The metallographic observation and hardness experiment were done and the results of numerical simulation was finally verified.
Study on Corrosion Inhibitor Technology in Gas Pipeline
Authors: Zheng Yun Ping , Ren Cheng Qiang , Ai Shao Ping , Zhang Feng , Shan Jiang
Published: August 2011

With the advance of the exploration and development technology, the corrosion problem in oil and natural gas industries has attracted more and more attention due to the appearance of H2S, CO2 and other corrosion medium in the oilfields. 20G steel was used as materials of the gas pipeline in P5 gas field. Corrosion failure of the gathering pipeline of No. 03 well was found in 2009. Therefore, the inhibitor CT2-4 was suggested to be used in the field. The anti-corrosion technology was discussed based on weight loss and electrochemical methods. According to the corrosion environment, the inhibition rate of CT2-4 is higher than 85% when its dosage is more than 125mg/L. The corrosion rate is decreased below 0.076 mm/a. The electrochemical results discover CT2-4 is a mixed-type inhibitor. In order to promote the anti-corrosion efficiency, the pre-film was investigated also. It shows the amount of prefilming and prefilming time are 1250 mg/L and 4h.
Parameter Optimization and Numerical Simulation of Dust-Collecting and Dedusting System with Air Curtain in Heading Face
Authors: Zhang Jian Zhuo , Zhu Tian Zi , Gao Meng , Li Kang Kang
Published: August 2011

A new type of dust-collecting and dedusting system with air curtain was developed to solve the problems of the dust-prevention in mine tunnel. The speed of air-curtain fan, the structure size and pressure of dedusting duct are the critical factors, which effect dust control of the whole system. In order to achieve optimal efficiency of dust control, the simulation was conducted with FLUENT(computational fluid dynamics software) to analyse the air-curtain fan surface path lines and dust particle tracks at different wind speeds of air curtain fan, dedusting duct diameters and outlet pressures. We obtained the law of fan speed, the diameter and outlet pressure of dedusting duct, which effect the whole system on dedusting. This law would play a guiding role on the structural optimization of dust-collecting and dedusting system with air curtain.
Research on a Scheme of Real-Time Measuring of Lubrication Oil Quantity in an Aero-Engine Tank
Authors: Xu Rang Shu , Chen Xiao Wen , Yang Jian Ming , Dong Zhi Wei , Bai Min Li
Published: August 2011

The composition and principles of the digital measuring system was investigated on the basis of digital oil measuring method. Fly attitude-oil quality - measuring height data tables were generated by using UG software calculation of oil quantity characteristics. Then the oil surface angle under different fly attitude and overload was calculated through coordinate transformation method. Finally the amount of oil was calculated by three-dimensional liner interpolation method. Meanwhile, the free surface movement of lubricating oil tank under different overload was simulated through VOF numerical model. The results showed that using UG software to build model and generate fly attitude-oil quantity-measuring height data tables is accurate and useful. The VOF model method is a complement to digital measurement, which can track the phase interface of continuum, analyze the movement of oil qualitatively and calculate the dead volume of digital method.
Research on the Simulative System of Engine-Thermoelectric Source
Authors: Wang Neng Huan , Zhang Zheng , Chen Yu Shan
Published: August 2011

A car engine-thermoelectric source system is constructed. The simulation procedure of the system shows in the following. With the using of AVL-BOOST software, the Operating condition of this system is simulated according to the structure of the engine and the temperature, velocity, pressure of the exhaust are obtained, which are used as the initial conditions of the thermal power. The geometry and mathematical model of thermoelectric generator is established and numerical calculation is done with the Star-CD software. This paper focuses on a type of four-stroke gasoline engine-intramural thermoelectric system and gives a calculation instance of the generator’s components.
Modification and Analysis on Inlet and Outlet Angle of Turbodrill’s Cascade Blade Profile
Authors: Zhang Xiao Dong , Gong Yan , Gou Ru Yi , Li Jun Hua , Wu Jian Ping , Jiang Zhong Jian
Published: August 2011

The structure angles should be calculated in the process of turbodrill’s cascade blade profile design. The angles are calculated according to the design parameters, which is the inlet and outlet flow angles of the cascade, but while fluid is flowing in the cascade, there are difference betweens the inlet flow angle and inlet structure angle as well as outlet flow angle and outlet structure angle in the cascade. The flow angles can’t be directly considered as the blade profile’s structure angles, so it is necessary to modify the calculated flow angles to obtain structure angles. Through the analysis, in order to improve the performance of the turbodrill, the flow angles should be modified to get the structure angles toward reducing direction. In this paper, the hydraulic efficiency and circumferential force fx are selected as evaluation parameters , cascade CFD models are built and calculated with the different modified angles. What’s more, the modified inlet and outlet flow angle impact on the turbine performance has been analysed , the given angle modification range is greatly narrowed in existing literature, which allow the designers determine modified value easily in the angle modification process.
Synchronous Rectification Strategy for LLC Resonant DC-DC Converter
Authors: Xu Zhen , Zhang Guo Xing
Published: August 2011

High efficiency /high power density is one of the hottest research spots in power electronics technique. Due to simple structure and high conversion efficiency, the LLC resonant DC-DC converter has great utilization potential in many application areas. To improve the conversion efficiency and the power density further, synchronous rectifier is widely adopted at the secondary-side. Based on the existed synchronous rectified LLC resonant DC-DC converter reviewed in this paper, advantages and disadvantages are analyzed and compared in detail. A novel primary-side current sensing strategy and a new current driving method for voltage-doubler rectifier are presented. Finally, this paper proposes a family of novel single package structure for synchronous rectifier from the view point of power electronics integration to improve the performance further.