Table of Content

27 January 2011, Volume 45 Issue 01 Previous Issue    Next Issue

Metallography and Metallurgical Technology

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Robust Design for Characteristic Part Stamping Based on Statistic Analysis of Variation of Material’s Property WANG Wurong1，2,YOU Jie2,ZHANG Xinpeng2,3,LI Shuhui2,LIN Zhongqin2 2011, 45 (01):  1-0005.  Abstract ( 3783 )   Save The statistic analysis and robust design theory were combined to study the selection of robustness process parameters for a characteristic case stamping based on the statistic analysis of material properties’ variation. The derived robust parameters were obtained according to the best quality control exponent (Cpk) and lowest wastes. The parameters were verified with the smallbatch experiments. Related Articles | Metrics

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Numerical Analysis for Forming Limit of Welded Tube in Hydroforming YANG Taibo，YU Zhongqi，XU Changbao，LI Shuhui 2011, 45 (01):  6-0010.  Abstract ( 4058 )   Save The model of electric resistance welding (ERW) tube, which reflects welded seam, heat affected zone and base material, was built up in finite element simulation. The ratio of strain increment was adopted as a necking criterion of tube in hydroforming numerical simulation. Furthermore, using the above method, the forming limit curve of QSTE340 ERW tube was determined. The corresponding forming limit test of QSTE340 ERW tube was completed using the processing path calculated form numerical simulation. Compared with the experiment the forming limit curve obtained by this method is in agreement with the experimental data. It is proved that the hydroforming forming limit of welded tube calculated based on numerical simulation is believable. Related Articles | Metrics

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Instability Analysis and Experimental Study of Micro Stamping Process with Thin Sheet HU Peng，PENG Linfa，LAI Xinmin，ZHANG Weigang 2011, 45 (01):  11-0014.  Abstract ( 3803 )   Save Focusing on the size effect which appears during the process of micro scale stamping, a new fracture criterion was derived from the constitutive equation based on strain gradient. Then, the stamping process of thin sheet was studied to obtain the relationship between the forming depth and strain. As a result, the limit of forming depth could be predicted accurately. Finally, a series of micro stamping experiments were conducted, which shows that the new fracture criterion is available. Related Articles | Metrics

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TwinArc TIG Welding with Ultrasonic Excitation WANG Jianjun1,LIN Tao2 2011, 45 (01):  15-0018.  Abstract ( 4267 )   Save In order to enhance the mechanical properties of weld by using ultrasonic vibration, a new method of twinarc tungsten inertgas (TIG) welding was developed. The welding will be completed by jointly using combined ultrasonic arc and ordinary DC arc technology. The ultrasonic arc was used for injecting ultrasound excitation into the molten pool to improve weld quality, and the DC arc was used as main heat source to increase deposition efficiency. The feasibility experiment of the welding system was done by using the steel 304. Metallographic analysis shows that the method can thin the microstructure of weld. The tensile testing under nature temperature indicates that the method can improve tensile properties of the weld effectively. Related Articles | Metrics

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Wear Mechanism of Tool in Milling HighStrength Titanium Alloy TC18 WANG Qichen， MING Weiwei， AN Qinglong, CHEN Ming 2011, 45 (01):  19-0024.  Abstract ( 3708 )   Save As TC18 is difficult to machine, the cutting speed and tool life are the main obstructions to improve the production efficiency and manufacturing cost control when machining TC18. This paper presented the tool wear pattern and tool wear mechanism of milling TC18. The results show that in the same cutting parameters, the carbide tool with PVD coating (TiN+TiAlN) has longer tool life than uncoated tool, the wear pattern is cater for diffusion and adhesive in the rake face after coating desquamated; while the wear pattern of uncoated tool is tipping. Related Articles | Metrics

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Magnetic Field Distribution in Resistance Spot Welding Nugget under Permanent Magnet SHEN Qi1，LI Yongbing1，LI Ruihua2，CHEN Guanlong1 2011, 45 (01):  25-0029.  Abstract ( 4897 )   Save Distributions of magnetic field, both external and induced, in nugget region of resistance spot welding (RSW) under permanent magnets were investigated using numerical simulation method. Based on the complex magnetic force distribution, the fluid flow behavior in RSW was systematically analyzed. The results show that the induced magnetic field predominates in RSW process under the permanent magnets. The complex magnetic flux density gradually increases from the center to the edge of the weld nugget, while the radial magnetic flux density gradually decreases with the increasing working distance of permanent magnets. Two perpendicular magnetic component forces exist in the nugget. One acts in the axisymmetric plane of the electrodes generated by the induced magnetic field, the other acts vertically to the plane generated by the external magnetic field. Driven by the complex magnetic force, the molten metal in the nugget would flow with high velocity in both the axisymmetric plane of the electrodes and the circumferential direction perpendicular to the plane. Related Articles | Metrics

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Impact of Plasticity Deformation on Microstructure and Toughness of High Strength Pipeline QI Lihua1,2,NIU Jing1,2,YANG Long1,FENG Yaorong1, JI Lingkang1,ZHANG Jianxun2 2011, 45 (01):  30-0034.  Abstract ( 4216 )   Save The effects of plastic deformation on the microstructure evolution and toughness properties of X100 pipeline structure steel were studied by scanning electron microscope (SEM), transmission electron microscope (TEM) and mechanical test. The results show that both acicular ferrite and granular bainite change remarkably with the value of stress under the same aging temperature and time. Simultaneously, the high density dislocation agglomerates around the M/A island, forms the subgrain boundary and the crystal boundary. After the deformation, the grain sizes decrease, while there are many subgrain structures distributed in crystal, and the material impact toughness drops remarkably due to M/A constitution distributed on the crystal boundary and the deformation flaws. Correspondingly, the sensitive coefficient of strainaging of grade X100 pipeline meets the needs when the temperature is above -34 °C. Related Articles | Metrics

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Effect of Mechanical Properties of Cu10%Al4%Fe Alloy Prepared by Equal Channel Angular Extrusion GAO Wanru，CHENG Xianhua 2011, 45 (01):  35-0039.  Abstract ( 3907 )   Save Aluminum bronze alloy (Cu10%Al4%Fe) was fabricated by equal channel angular extrusion (ECAE) process. The effects of preheating temperature, extrusion numbers and annealing treatment on the surface appearance, microstructure and mechanical properties of the aluminum bronze alloy were investigated. The results show that the appropriate preheating temperature is 650 °C. When the ECAE pass number increases from 1 to 4, the hardness, yield strength and the plastic properties increase gradually. The alloy has the best mechanical properties after 60 min’s annealing treatment at 500 °C. Related Articles | Metrics

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Effect of Technological Parameters on LaserControlled Thermal Stress Cutting Quality of Ceramics HU Jun,CAO Qianqian,LUO Jingwen 2011, 45 (01):  40-0044.  Abstract ( 4079 )   Save In order to study the distributions of temperature field and thermal stress field, a threedimensional axial symmetric model of alumina ceramic was established. This paper described the thermal stress’s variation of the cutting point and studied the influence of laser power, ceramic thickness and cutting speed on the temperature field and thermal stress field. The model was validated by comparative experiments. The results show that with the increase of the tensile stress, the microcrack becomes deeper, which induces more surface particles to run off, then the roughness increases. Related Articles | Metrics

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Modeling Crushing Pressure and Liner Wear of Cone Crusher DONG Ganga，FAN Xiumina，b，NEUMAYER Johannesa 2011, 45 (01):  45-0049.  Abstract ( 3785 )   Save The rock material compression experiments were carried out and a pressure model relating compression ratio and particle size distribution to compression pressure was presented. The kinematics of rock material in crushing chamber was analyzed and a method for calculating the pressure distribution on cone crusher liners was proposed. Calculating the components of crushing pressure and putting them into wear prediction model, the liner wear of cone crusher was achieved. The results show that the model is consistent with the research data, and the prediction of wear is realized. Related Articles | Metrics

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Rolling Contact Fatigue Life Prediction on Bearing Steel Pre-residual Stress Surfaces Induced by Hard Turning LI Zhen１,ZHANG Xiangqin1，ZHANG Xueping1,LIU C Richard2 2011, 45 (01):  50-0055.  Abstract ( 5006 )   Save To predict the effect of the hard turninginduced residual stress on the rolling fatigue life of bearing steel, 2D rolling contact fatigue life model characteristic with plane strain was developed based on MARC. The residual stress on the machined surface and subsurface from the hard turning bearing steel was applied to surface and subsurface of 2D model correspondingly. The rolling contact stress distribution was simulated under the typical services, and the rolling fatigue life of contact interface was predicted by Miner law based on the SN life theory under compressive stress. After the analysis of rolling fatigue life under different conditions, the effect of different friction, rolling velocity, load on fatigue life with hard turninginduced residual stress was quantitatively investigated. The investigation shows that the hard turninginduced compressive residual stress increases 10%—30% the rolling fatigue life of bearing steel, and the load has the greatest effect on rolling fatigue life while the fiction coefficient has the minimal effect. Related Articles | Metrics

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Research on High Speed WireCut Electrical Discharge Machine Based on Analysis of Interelectrode Flow LIU Zhidong,WANG Zhenxing 2011, 45 (01):  61-0065.  Abstract ( 3912 )   Save A simplified interelectrode flow model of wirecut electrical discharge machine was proposed. The effect of the plate length, velocity and gap width respectively on pressuredifference flow and shear flow was investigated. The compound gap flow formed by combining the pressuredifference flow and shear flow was analyzed. By adding coaxial nozzle and adopting high energy, a test was done to compare the cutting efficiency and surface quality of the single casting fluid supply dominated by shear flow with that of the combination fluid supply supplemented by highpressure spray liquid. The results show that compared with the single casting fluid supply, the gap condition of the combination fluid supply is improved obviously: the maximum cutting efficiency nearly reaches 220 mm2/min, increases by 20% and little surface burns are got, which verifies the effect of the composition of pressuredifference flow and shear flow. Related Articles | Metrics

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Onsite Measurement of Sphericity Based on HighPrecision Sphere Grinder LIU Bing1,2,XU Liming1,2,CHAI Yundong1,XU Kaizhou1,LI Dongdong1 2011, 45 (01):  66-0070.  Abstract ( 3944 )   Save A new method of onsite measuring sphericity was proposed based on highprecision sphere grinding machine. The measuring basis and the automatic measuring instruments were setup based on the sphere grinding machine. The radius variation as well as corresponding longitude and latitude values of the measuring points evenly distributed over sphere were measured. The mathematical models of the spherical center coordinate and the least square radius were established based on the least square method. The least square sphere was then fitted by the measured values. The comparison charts of the measured sphere and the least square sphere were drawn. The onsite measurement of sphericity was achieved and the result shows the feasibility comparing with traditional micrometer based measuring method. Related Articles | Metrics

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SawTooth Chip Formation Process and Mechanism in Hard Turning AISI 52100 Bearing Steel WU Shenfeng，ZHANG Xueping 2011, 45 (01):  71-0077.  Abstract ( 4421 )   Save A thermalmechanical orthogonal cutting finite element model (FEM) was established by Abaqus/Explicit to explore the sawtooth chip formation process and mechanism in hard turning AISI 52100 steel. The observation of stress distribution, temperature distribution and mesh distortions along cutting time in high and low speed machining processes contributes to demonstrate the adiabatic shear mechanism of sawtooth chip formation process of AISI 52100 bearing steel. Firstly, a short horizontal adiabatic shear band initiates in front of the rake face; the short band gradually extends to the free surface from the end of the shear plane as the rake face advances to push the work material more severely; sawtooth chip forms as the adiabatic shear band slides. “Adiabatic shear” is the primary mechanism to form sawtooth chip morphology in machining AISI 52100 bearing steel, crack initiates after the formation of adiabatic shear band; cutting speed is the driving force of the microcrack initiation in shear band and subsequent propagation to the tool tip. The friction condition in second shear zone strengthens the tendency of sawtooth chip formation process. Related Articles | Metrics

Mechanical Engineering

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Optimization Model of Ship’s Equipment LORA Based on LINGO HE Chunyu,JIN Jiashan，SUN Fengrui 2011, 45 (01):  78-0082.  Abstract ( 3807 )   Save Level of repair analysis (LORA) plays an important role in the supportability analysis of ship equipment. There are much less LORA models dealing with few data, so, an optimization model based on linear interactive and general optimizer (LINGO) is offered to solve the 3I3R ship equipment, which is solved by programming. It is validated by a case that the model of LORA is practical and effective. Related Articles | Metrics

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Preparation and Characteristics Analysis of Friction and Wear Behavior of MPTS/MPTES Composition Selfassembled Film XU Ying1,2，ZHOU Hua1，CHENG Xianhua2 2011, 45 (01):  83-0087.  Abstract ( 7475 )   Save MPTS/MPTES selfassembled film was fabricated on singlecrystal silicon substrates by molecular selfassembly process. Atomic force microscope (AFM), Xray photoelectron spectrometry (XPS) and contact angle measurer were used to characterize the thin films. The tribological properties of the films sliding against GCr15 steel ball were evaluated on a DFPM reciprocating friction and wear tester. The results show that the MPTS/MPTES film has excellent hydrophobic and friction and wear behavior properties compared with MPTS film and MPTES film. The cause is that the MPTS/MPTES film has big size molecule which can endow some fluidity and flexibility to the film and closepacked molecules or radicals on the bottom are rigid which can bear certain load. Related Articles | Metrics

Bilogical Science

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Isolation and Structural Identification of a Tetraene Macrolide Produced by Streptomyces hygrospinosus var. Beijingensis YAO Fen1，KANG Qianjin1，LIN Shuangjun1，ZHU Changxiong2， YOU Delin1，DENG Zixin1 2011, 45 (01):  88-0091.  Abstract ( 3849 )   Save A tetraene compound was purified from the secondary metabolites of Streptomyces hygrospinosus var. Beijingensis, the producing strain of Agroantibiotic 120. The results of LCMS on molecular weight and NMR on structural identification show that it is Tetramycin B with the UV absorption spectrum of tetraene macrolide antibiotics. The bioassay result shows it inhibits the growth of Saccharomyces cerevisiae, indicating it is one of the effective components in Agroantibiotic 120. Related Articles | Metrics

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An Improved Algorithm for Protein Structure Prediction Based on Contact Map LU Hengyun,YANG Genke,PAN Changchun 2011, 45 (01):  96-0100.  Abstract ( 3740 )   Save An improved contact map reconstruction(COMAR) algorithm was introduced to reconstruct 3D structures from protein contact maps. After guessing a possible set of distances consistant with contact map, the proposed algorithm generates a random initial set of 3D coordinates, and then iteratively applies two local correction and perturbation techniques to the current set of coordinates. The results show that when the threshold of the contact map computation is increased, the reconstructed structure is more similar to the native structure. In addition, the RMSD computed by improved COMAR is lower than COMAR in the same case. Related Articles | Metrics

Physics

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High Speed Video Photography System Based on Principle of Optical Polarization TAN Xiuwen,HUA Xueming,LI Mengxing,YE Xin,WANG Fei 2011, 45 (01):  101-0104.  Abstract ( 3647 )   Save Through the selection of laser for backlight, this paper established a set of highspeed photography optical system based on light polarization principle. Considering the difference between arc shooting and droplet shooting, the system suppress the arc light using different ways based on the principle of optical polarization when there is a backlight or not. The system does a good job in the following welding practice. Related Articles | Metrics

Management Science

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Optimal Timimg and Equlibrium Price for Control Rights Transfer of Company CHEN Zhuming 2011, 45 (01):  105-0109.  Abstract ( 3493 )   Save By applying real option game theory, an equilibrium price and optimal timing under the condition of nonperfect information for the controlling shares transfer were given, and the comparative static analysis was made for the main factors which affect the the optimal timing. The results show that, assuming other conditions remain unchanged, the better the quality of target companies, the smaller M and A sunk cost, the higher the percentage holding, the greater the expected synergies, the more low transfer price will result in the transfer of control sooner. The higher industry growth rate and the volatility, the faster the transfer of control, and there is a double effect. Related Articles | Metrics

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Study on the Contribution Rate of Talents Capital Based on CobbDouglas Production Function Combined with Logistic Regression LIN Longbin1，YU Jiamin2 2011, 45 (01):  110-0114.  Abstract ( 3822 )   Save Taking Shanghai Minhang district as an example, a CobbDouglas production function combined with Logistic regression was built to figure out Minhang’s contribution rate of talents capital. Finally, suggestions on applicability of industry, statistics of elementary data and allowance for nonschooling human capital were proposed to improve the CobbDouglas model. The results show that, from 1992 to 2008, Minhang’s contribution rate of talents capital is equal to 24.6%. Especially from 2005, the investment on talents capital rises up, and is consistent with the economic growth of Minhang. This indicates that human capital’s promotion on Minhang’s economic development is evergrowing. Related Articles | Metrics

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Dynamic Relocation Problem in an Automated Storage/Retrieval System CHEN Lu1,LANGEVIN André2,RIOPEL Diane2 2011, 45 (01):  115-0119.  Abstract ( 4079 )   Save An integer linear programming model was formulated to address the optimization problem of relocation in an automated storage/retrieval system. A twostage heuristic method was developed to generate an initial solution. A tabu search algorithm was proposed to improve the solution. Experimental tests were conducted to evaluate the performance of the proposed optimization algorithm based on various data settings. The experimental results show the effectiveness and the robustness of the algorithm. The efficiency of the handling machine and the utilization of the warehouse are improved by applying the algorithm. Related Articles | Metrics

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Integer Programming Allocation Model of Empty Container by Sea Transportation for Liner Operators’ Cooperation YANG Yang 2011, 45 (01):  120-0124.  Abstract ( 3743 )   Save To reduce the distribution cost of empty containers, this paper presented an integer programming allocation model of empty containers by sea transportation for liner operators’ cooperation. The model is based on the allocating resources shared in liner operators, and at the same time considers the factors, such as rent cost, transporting cost, shipping direction, shipping capacity and reachability. The optimization objective is, when all liner operators who participate in the cooperating allocation can guarantee the shipping of the full containers and use each other’s allocating resources, to minimize the comprehensive obtaining cost for satisfying all empty containers demands which include allocating and renting empty containers. The model is followed by a numerical example, with an optimized scheme of empty container allocation by sea transportation for liner operators’ cooperation, to show that the model is practical and efficient. Related Articles | Metrics

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Pricing Strategy of Port Enterprises under Cooperation Condition Based on Located Spatial Model ZHOU Xin1,2，SHA Mei1 ，ZHENG Shiyuan1，JI Jianhua2 2011, 45 (01):  125-0129.  Abstract ( 3635 )   Save Based on modified Hotelling model, this paper built the pricing model of port enterprises under cooperation condition, compared the demand and profits of port enterprises under competition and cooperation condition. The studies indicate that when the service levels are the same, the total demand and profits of the adjacent port enterprises are affected by their locations, when the service levels are not the same, they are influenced by the locations and service levels. Related Articles | Metrics

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Marketability Restricted Assets Pricing Model Considering Heterogeneous Agents HU Ying,WU Chongfeng 2011, 45 (01):  130-0133.  Abstract ( 3492 )   Save A marketability restricted assets pricing model considering heterogeneous agents was built based on the hypothesis of heterogeneous agents and the marketability option pricing model. It was pointed out that the risk pricing difference raised by the heterogeneous hypothesis not only directly affects the fundamental pricing of assets, but also indirectly affects the discounts of marketability restricted assets by affecting the marketability option pricing attached on assets. The bigger the risk pricing difference between the marketability restricted assets trader and marketable assets trader is, the bigger the marketability restricted assets discount is. And both the volatility of assets price and the restricted period have positive impact on the discounts of marketability restricted assets. Related Articles | Metrics

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Evaluation of HighTech Research Project Based on Internal Fuzzy TOPSIS and AHP ZHANG Shouhua，SUN Shudong 2011, 45 (01):  134-0138.  Abstract ( 4079 )   Save An evaluation index system of hightech research project was established, and the evaluation model for hightech research project was put forward based on analytical hierachy process (AHP) and internal fuzzy technique order preference by similarity to an ideal solution (TOPSIS). And the weight of evaluation index was made using AHP, the interval fuzzy matrix was set using fuzzy theory. The positive ideal solution, negative ideal solution and proximity were calculated. The rank of hightech research project was made by comparing the proximity. At last, an example was discussed to validate the practicability and feasibility of the established index system and model. Related Articles | Metrics

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An Exploratory Factor Analysis of Entrepreneurial Management Scale ZHU Kaiduan1，JIANG Qinfeng1，WANG Zhongming2 2011, 45 (01):  139-0143.  Abstract ( 3525 )   Save Chineseversion entrepreneurial management (EM) scale is obtained via back translation. Using 277 domestic firms’ data, the study validates the factor structure and crossculture comparability of EM model in Chinese cultural background, together with its theoretical implications. Result reveals that EM factor model showed reasonable reliability and crossculture comparability. Related Articles | Metrics

Chemical Engineering

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Statistical Analysis for LowField Nuclear Magnetic Resonance Batch Data of Sweet Corn SHAO Xiaolonga,b,ZHU Jiangweib,LI Yunfeib 2011, 45 (01):  144-0148.  Abstract ( 3936 )   Save To obtain the effect and quantitative information of water components in sweet corn by different blanching temperature, Statistical analysis system (SAS) was applied to deal with lowfield nuclear magnetic resonance (LFNMR) data of blanched sweet corn. Statistic analysis on batch raw data of LFNMR was performed by SAS system, including exponential fitting, principal component analysis (PCA) and partial least squares regression (PLSR). The corresponding SAS codes were provided. The fitting result of multiexponential model indicates that the percentages of two components with relaxation times (405-750 ms) and (50-70 ms) change distinctly. Three blanching temperature ranges: 20-40, 50-70 and 80-100 °C are roughly discriminated by PCA. PLSR does well in prediction of bound water in blanched sweet corn (determined coefficient is 0.974, root mean square error of crossvalidation is 0.32%). From the whole data processing, SAS programming performs efficiently on data management and analysis and gives valuable reference for LNNMR application. Related Articles | Metrics