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15 October 2009, Volume 30 Issue 10 Previous Issue    Next Issue
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Study on the problems of nonlinear input of hysteresis loop Feng, De-Zhi (1); Wang, Ying-Chun (1); Zhang, Hua-Guang (1); Cao, Ning (1) 2009, 30 (10):  1369-1372.  DOI: - Abstract ( 281 )   HTML   PDF (2143KB) ( 581 )   Analyzing the physical properties of the hysteresis loop and combining them with adaptive control technique, a new robust adaptive control scheme is developed to solve the tracking control problem of a nonlinear system where the hysteresis loop is input, instead of constructing an inverse hysteresis loop in conventional way. The input of the system is a backlash-like hysteresis loop of which the model is expressed in differential equation where the parameters are unknown but their bounds are known. The new scheme ensures the global stability of nonlinear systems with effective tracing results provided for the given signal, and its validity has been verified through simulation. References | Related Articles | Metrics

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A new immune clonal algorithm and its applications to CVRP Shi, Gang (1); Jing, Yuan-Wei (1); Ma, Jia (1) 2009, 30 (10):  1373-1376.  DOI: - Abstract ( 251 )   HTML   PDF (877KB) ( 532 )   Based on the clonal selection theory, a new immune clonal algorithm (ICA) was put forward with the cloning operator introduced in to solve the CVRP problem. Furthermore, in the algorithm, the operators of clonal proliferation, super mutation and clonal selection were adopted to provide more opportunities for the excellent individuals in the group to get clonal proliferation so as to realize the affinity maturation, improve the diversity of the distribution of group of immune bodies and realize balance between the searching in depths and the optimizing in widths. Simulation results shows that the algorithm has a remarkable reliability of global convergence and convergence rate to solve effectively the CVRP problem. References | Related Articles | Metrics

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Alpha wave-based asynchronous brain-computer interface system Zhao, Hai-Bin (1); Wang, Hong (1); Li, Chun-Sheng (1) 2009, 30 (10):  1377-1380.  DOI: - Abstract ( 286 )   HTML   PDF (847KB) ( 916 )   A brain-computer interface (BCI) system was built using Alpha wave, including EEG data acquisition/analysis, feature extraction and classification. The BCI system was real-time analyzed, and the results indicated that its working mode is asynchronous, and it can be started up whenever it is needed. It is a more natural human-computer interaction system, from which any one of four commands can be chosen as output. Experimental results showed that the BCI system has high classification accuracy and practicability. References | Related Articles | Metrics

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DRM-based approach to identifying activity loops in business process reengineering Yuan, Hui-Lin (1); Wang, Lei-Zhen (1); Wang, Ding-Wei (1) 2009, 30 (10):  1381-1384.  DOI: - Abstract ( 224 )   HTML   PDF (1146KB) ( 528 )   A new approach named DRM (distance reachable matrix) was proposed by introducing the value of distance in the reachable matrix so as to show directly the shortest distance at intervals of activities and find out the unreasonable activity loops quickly in business process. The definition and operating rules of DRM and others related to DRM were described in detail. Numerical examples showed that the activity loops and routes and shortest distance were all found out quickly by the approach proposed, thus providing a new resolution for the BPR (business process reengineering). References | Related Articles | Metrics

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Simulation-based optimization of the policy combining three-echelon network stochastic inventory with pricing Gao, Jing-Mei (1); Wang, Ding-Wei (1) 2009, 30 (10):  1385-1389.  DOI: - Abstract ( 239 )   HTML   PDF (1028KB) ( 519 )   How to decide the policy combining inventory and pricing with both controllable lead time and elastic demand is the problem to be solved. Because the customer arrival time follows Possion distribution and customers' demands/purchase and lead time are all stochastic with suppliers' limited production capacity in inventory system, it is difficult to describe various complex and stochastic factors by analytical method. A mathematical model is thus developed aiming at maximizing the total profit with the price, lead time and inventory control strategy as variables in decision making. Then, the simulation-based optimization (SBO) is implemented to solve the problem via combining the simulation with particle swarm optimization (PSO) algorithm. A simulation is done as example to verify the feasibility and the effectiveness of both the mathematical model and SBO. References | Related Articles | Metrics

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Game analysis of ordering model for batch between buyer and supplier in stochastic demand Wei, Jing-Min (1); Tang, Jia-Fu (1); Liu, Ying-Ying (2); Jin, Ya-Ling (2) 2009, 30 (10):  1390-1393.  DOI: - Abstract ( 290 )   HTML   PDF (183KB) ( 585 )   Analyzing the ordering model for batch in stochastic market demand without cooperation and discount game, a Stackelberg price-discount game model is developed between the buyer and supplier. With the product's price discount provided to buyer by the supplier who shall share partly the inventory venture, the batch quantity ordered by the buyer will increase so as to increase the profits of both parties and supply chain. Furthermore, the cooperation game model and profit sharing are analyzed, and a numerical example is given to compare the optimal policies and relevant profits between both parties on the basis of those game models proposed. References | Related Articles | Metrics

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Flexible integrated charge planning for steel making Dong, Hong-Yu (1); Huang, Min (1); Wang, Xing-Wei (1); Zheng, Bing-Lin (2) 2009, 30 (10):  1394-1397+1401.  DOI: - Abstract ( 260 )   HTML   PDF (1135KB) ( 490 )   Describing the problem of integrated charge planning for steel making production mode based on flexibility-oriented order, the generalized and restricted flexibility is defined conceptually and the integrated technological procedure is designed. With several single-objective optimization models developed and the restrictive conditions given through penalty function method, a new hybrid algorithm is designed introducing the harmony search algorithm as the local search strategy for the variable neighborhood search algorithm. The flexible and rigid requirements of steel weight are analyzed comparatively. In view of the throughput, steel weight without requirement, useful capacity and total incidental operation cost, the validity of the models and algorithms proposed is exemplified and verified. References | Related Articles | Metrics

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A method of QoS measurement of web service based on service using information Liu, Guo-Qi (1); Zhu, Zhi-Liang (1); Liu, Ying (1); Wang, Qin (1) 2009, 30 (10):  1398-1401.  DOI: - Abstract ( 279 )   HTML   PDF (296KB) ( 606 )   The existing measuring methods of QoS lack versatility because they only take the common attributes of Web service into consideration but neglect the domain attributes. The measurements of QoS are therefore divided into two categories, i.e., the constrained Web service and unconstrained one with their respective measuring methods proposed. For the constrained QoS measurement, an algorithm based on constrained information is proposed. As for the unconstrained QoS measurement, the proposed algorithm can adjust automatically the QoS indices and its corresponding coefficients through analyzing service using information. The implemented platform and analysis of experimental results are provided, with which the applicability and effectiveness of the method proposed are verified. References | Related Articles | Metrics

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A prediction framework based on extreme learning machine for secondary structure of protein Zhao, Xiang-Guo (1); Wang, Guo-Ren (1) 2009, 30 (10):  1402-1405.  DOI: - Abstract ( 228 )   HTML   PDF (243KB) ( 739 )   A prediction framework was proposed for training the secondary structure model of protein, based on a new effective learning algorithm, i.e., the extreme learning machine (ELM). Then, to merge the predicted results together better, a probability-based combining (PBC) algorithm was proposed with a Helix-post-processing (HPP) algorithm set out according to the biological features of protein's secondary structure, which will provide efficient post-processing effect on the predicted results after merging so as to improve their accuracy further. The experiments were carried out on the datasets CB513 and RS126 separately, and the predicted results showed that the accuracy of the proposed algorithms is satisfactory especially the training time that is shortened greatly. References | Related Articles | Metrics

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Efficient implementation of decoding algorithm of low density lattice codes Wang, Xiao-Song (1); Chang, Gui-Ran (1); Ning, Xuan-Jie (1) 2009, 30 (10):  1406-1408.  DOI: - Abstract ( 184 )   HTML   PDF (849KB) ( 519 )   The low density lattice codes (LDLC) and its decoding algorithm were described. For the most time-wasted steps, such as convolution, stretching and periodic expansion, an efficient implementation scheme was designed and came into effect in combination with the relevant technique of digital signal processing. Simulation results verified the excellent performance of LDLC and showed that the proposed scheme was available to shorten effectively the time for each iteration step in decoding. References | Related Articles | Metrics

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Two-step mixed particle filtering for target tracking Wang, Ai-Xia (1); Wu, Peng (1); Li, Jing-Jiao (1); Wang, Xu (1) 2009, 30 (10):  1409-1412.  DOI: - Abstract ( 303 )   HTML   PDF (431KB) ( 606 )   The success rate and accuracy of target tracking via particle filtering are closely related to target speed and number of particles. More particles will enable the algorithm to track target faster, while the real-time performance drops. To solve the problem, a new two-step mixed particle filtering algorithm was proposed. During the first step, based on the distance-angle model, some particles are used to estimate the target position roughly. During the second step, the mean shift algorithm is used to estimate the target position accurately and, meanwhile, the particle filter is used to regulate the windows' size of mean shift adaptively. Experimental results showed that the proposed algorithm can track deformed target in real time at high speed. References | Related Articles | Metrics

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Model of QoS degrading threshold and its computation for avoiding useless re-selection Dai, Yu (1); Yang, Lei (2); Zhu, Zhi-Liang (1); Zhang, Bin (2) 2009, 30 (10):  1413-1416.  DOI: - Abstract ( 236 )   HTML   PDF (120KB) ( 596 )   To avoid the useless re-selection which results in unideal optimization of QoS, it is necessary to judge whether the degradation level of QoS will affect the constraint conditions which the globally combinational QoS should satisfy. Thus, a model of QoS degrading threshold was developed to reflect the relation between the degradation level of QoS and the satisfaction of constraint on global QoS so as to trigger off the useful re-selection for better optimization. According to the structure of flow of composite service, the computational rules of the QoS degrading threshold and corresponding methods were given. Experiment results showed that the proposed methods are effective for avoiding useless re-selection and providing the ideal optimization for QoS through re-selection. References | Related Articles | Metrics

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Micromorphologic study on the super-fine grain and high-strength IF steel Qiao, Li-Feng (1); Zhang, Hong-Mei (1); Liu, Zhen-Yu (1); Wang, Guo-Dong (1) 2009, 30 (10):  1417-1420.  DOI: - Abstract ( 267 )   HTML   PDF (555KB) ( 555 )   The effect of annealing process on the micromorphology of the new-type SFG HSS (super-fine grain, high-strength steel) sheet was studied via cold rolling and annealing in lab. The observation results of microstructure showed that the super-fine grains can be obtained by improving chemical composition and controlled rolling annealing, and the tiny Nb(C, N) precipitates (10~40 nm) are found and they are rare in the vicinity of grain boundary, i.e., the PFZ zone (precipitate-free zone) which exists only the one side of grain boundary. Moreover, some grain boundaries are merged together at part of trifurcate grain boundaries. Experiment results showed that the Nb precipitates in such steel are so tiny that the grain refining comes up to a very high degree and, due to the PFZ, the steel has a low ratio of yield strength to tensile strength with high elongation and favorable formability. References | Related Articles | Metrics

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Microstructure and mechanical properties of 710 MPa hot-rolled high-strength steel Yi, Hai-Long (1); Wang, Xiao-Nan (1); Du, Lin-Xiu (1); Wang, Guo-Dong (1) 2009, 30 (10):  1421-1424+1428.  DOI: - Abstract ( 708 )   HTML   PDF (551KB) ( 1675 )   The high-strength 8 mm-thick autobody sheets were prepared via TMCP on a 1750 mm hot tandem mill. Then, the microstructure and mechanical properties of specimens of the sheet were tested and investigated by means of optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the microstructure of specimen is mainly composed of fine-grained ferrite and carbides distributed along the ferrite grain boundaries. The yield and tensile strengths of specimens are about 650 and 740 MPa, respectively, and the values of strain hardening exponent (n) and plastic strain ratio (r) are 0.12 and 0.80, respectively, thus providing well-matched strength with toughness. In short, the fine-grained ferrite and TiC nano-precipitates play an effective role in strengthening the steel. References | Related Articles | Metrics

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Corrosion resistance of a 460 MPa high-strength bridge steel Gao, Cai-Ru (1); Du, Lin-Xiu (1); Wang, Lei (1); Wang, Yan-Feng (2) 2009, 30 (10):  1425-1428.  DOI: - Abstract ( 257 )   HTML   PDF (416KB) ( 777 )   A high-strength bridge steel, Q460qNH, was newly developed in lab via TMCP technology and its corrosion resistance was investigated through the wet-dry alternating accelerated corrosion tests and polarization curves resulting from electro-chemical experiment. Comparing Q460qNH with the high-strength bridge steel Q460q supplied by a certain steel-making plant and the high-quality weathering steel SPA-H, the results show that the corrosion resistance of Q460qNH approaches that of SPA-H and is obviously higher than Q460q. The weathering resistance of Q460q can be obviously improved if adding 0.2%~0.3%Cr, 0.15%~0.25%Ni, 0.2%~0.3%Cu as alloying elements in it. References | Related Articles | Metrics

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Hot ductility of Cr21 lean duplex stainless steels Fang, Yi-Liu (1); Liu, Zhen-Yu (1); Wang, Guo-Dong (1) 2009, 30 (10):  1429-1432.  DOI: - Abstract ( 296 )   HTML   PDF (368KB) ( 786 )   Hot ductility of two kinds of Cr21 lean duplex stainless steels was investigated by high-temperature compression/tension tests in the range from 950 to 1150°C, and the results showed the obvious difference between them in hot ductility. The effects of temperature, strain rate, ratio of phases and microstructure on the hot ductility of the two kinds of stainless steels were discussed, and it was found that increasing of stabilized ferritic elements and deformation temperature are beneficial to the improvement of hot ductility. While deformation at comparatively low temperature and high strain rate, cracks tend to nucleate at the interface of elongated austenite and ferrite and propagate in ferrite along the interface. References | Related Articles | Metrics

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Compression deformation behavior of semi-solid ZL201 aluminum alloy Wang, Ping (1); Lu, Wen-Quan (1); Cui, Jian-Zhong (1) 2009, 30 (10):  1433-1436.  DOI: - Abstract ( 486 )   HTML   PDF (1240KB) ( 565 )   The compression deformation of the semi-solid ZL201 aluminum alloy, prepared by the near-liquids continuous casting, was conducted on the Gleeble-1500 thermal simulator at different temperatures and strain rates. Then, a mathematic model was developed correspondingly via the regression analysis of simulation results. It was revealed that the higher the deformation temperature, the lower the compression stress if the strain rate is constant, and the compression on stress increases first then decreases with increasing strain rate if the deformation temperature is constant. The results can also provide the basic data for the numerical simulation of semi-solid alloy thixoforming and the optimization of process parameters for semi-solid metals. References | Related Articles | Metrics

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Laser cladding of Ni-based alloy on #20 steel surface and its high-temperature abrasive-wear behavior Zang, Chen-Feng (1); Zhao, Peng-Fei (1); Zhang, Xiao-Bin (1); Liu, Chang-Sheng (1) 2009, 30 (10):  1437-1440.  DOI: - Abstract ( 362 )   HTML   PDF (461KB) ( 850 )   Laser cladding of Ni-based alloy was implemented on the surface of #20 carbon steel specimens by use of NiCrSiB powder. Then, the phase composition of the cladding was investigated by XRD, with its high-temperature wearability investigated on an abrasion-wear tester and its surface morphology observed by SEM. The results showed that cladding has even and compact microstructure that has been integrated metallurgically with #20 carbon steel substrate. The microhardness of the cladding is 3 times greater than the substrate, but its high-temperature wearability is just about one third of the substrate. The reasons why the wearability is improved are mainly the highly metallurgical integration of the cladding with substrate, strengthening due to solid solution and that due to precipitation hardening from borides and boron carbonide. References | Related Articles | Metrics

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Development and application of platform of process control system for plate heat-treatment Zhao, Da-Dong (1); Xue, Jun-An (1); Wang, Zhao-Dong (1); Yu, Guang-Wei (2) 2009, 30 (10):  1441-1444.  DOI: - Abstract ( 318 )   HTML   PDF (825KB) ( 566 )   The architecture and functions of the platform of process control system for the plate heat-treatment in the Special Steel Plant of Baoshan were described briefly and discussed. According to the characteristics of heat-treatment needed in production, the data communication mode and load condition among the modules were analyzed in detail to provide a conceptual design for the system software. Based on the development in laboratory test platform, the software hierarchy of process control of which the number of communication modules can be changed was built. The process control systems of heat-treating furnace with roller path and quenching machine were integrated into a PC server. Testing results showed that such a hierarchy meets requirements for the reliable, stable and extensible operation in the process control system and simplifies the debugging procedure and maintenance of the system, thus improving the utilization ratio of PC server. References | Related Articles | Metrics

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Research and application on thermal stress model of billet continuous casting Ma, Jiao-Cheng (1); Zu, Ling-Yu (2); Liu, Wen-Hong (2); Xie, Zhi (2) 2009, 30 (10):  1445-1448.  DOI: - Abstract ( 302 )   HTML   PDF (1310KB) ( 565 )   To reduce the internal cracks and defects of billets, which were caused by the inappropriate secondary cooling operation during continuous casting, a 2-D thermal elastic-plastic stress model of billet was developed via the verification of the heat transfer model in solidification process. Then, the billet stress distribution was calculated before and after the optimization of water flowrate required for secondary cooling to find out the rules of billet stress distribution in the secondary cooling zone. Analyzing the influencing factors on the cracks in billet, some measures were proposed to prevent the billet from thermal cracks, thus providing theoretically foundation to study the effect of secondary cooling on the quality of billet and the way to optimize the water flowrate required for secondary cooling so as to improve the strand quality during continuous casting. References | Related Articles | Metrics

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Effect of thermal-fluid coupled field on alloy microstructure in continuous rheo-extrusion process Guan, Ren-Guo (1); Li, Jiang-Ping (1); Li, Xue (1); Xiao, Zhao-Hui (1) 2009, 30 (10):  1449-1453.  DOI: - Abstract ( 285 )   HTML   PDF (668KB) ( 603 )   To optimize the process parameters for preparing AZ31 Mg-alloy by continuous rheo-extrusion, the temperature and velocity fields at different casting temperatures were modeled by FEM simulation of which the results were verified through some tests to discuss the effect of thermal-fluid coupled field on the microstructure of AZ31 alloy. It was shown that the moving velocity of strand linearly decreases from shoe side to roll side and comes up to its maximum value near the roll surface in the continuous rheo-extrusion process to prepare the semi-solid AZ31 alloy, while the velocity at the shoe surface is zero. The strand temperature decreases gradually from sprue gate to the exit of the roll-shoe gap, and the isothermal line shifts to the roll side. The strand temperature at the exit is basically direct proportional to the casting temperature, and the optimal casting temperature resulting from simulation is in the range from 730 to 770°C for preparing the fine spherical-grain microstructure of the alloy. References | Related Articles | Metrics

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Thermal value theory and its application to energy-saving for continuous heating furnace Cai, Jiu-Ju (1); Sun, Wen-Qiang (1); Xie, Guo-Wei (1) 2009, 30 (10):  1454-1457.  DOI: - Abstract ( 280 )   HTML   PDF (338KB) ( 759 )   Some calculation formulas of thermal value were proposed for air/gas preheating and hot charging. Several pyrological indexes were compared, and the thermal value was found available to evaluate reasonably whether the heat is utilized efficiently in continuous heating furnaces. Then, a model of counter-flow heat transfer in heating furnaces was developed to investigate mainly the influences of air/gas preheating and hot charging on thermal value. The results showed that the thermal value increases with increasing preheating temperature, but its increase rate decreases with the continually increasing preheating temperature. The higher the hot charging temperature, the higher the increase rate of thermal value is. In the design of continuous heating furnace, short length should be chosen if charging temperature is high, whereas long length should be chosen if preheating temperature is high. References | Related Articles | Metrics

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Determining raceway boundary by image processing via high-speed video camera Sun, Ye (1); Luo, Zhi-Guo (1); Zou, Zong-Shu (1); Liu, Hong-Hua (1) 2009, 30 (10):  1458-1461.  DOI: - Abstract ( 358 )   HTML   PDF (564KB) ( 748 )   Developing a cold-state model of COREX melter-gasifier in its symmetric half and using a high-speed video camera to track tracer particles, the information on the moving particles in and around the raceway near observing panel can be obtained. Then, the scalar field of particle velocity in raceway can be obtained by processing a great deal of the data of moving particles. Compared with the observation results, the scalar field where the particle velocity is within 0.15 m/s is defined as the raceway. In such a way the boundary conditions can be provided precisely for the theoretical study and mathematical modeling of gas/solid flow and chemical reaction in and around the raceway of COREX melter-gasifier or blast furnace. References | Related Articles | Metrics

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Preparation of CuCr alloy by self-propagating high-temperature synthesis Dou, Zhi-He (1); Zhang, Ting-An (1); Niu, Li-Ping (1); He, Ji-Cheng (1) 2009, 30 (10):  1462-1465.  DOI: - Abstract ( 319 )   HTML   PDF (1107KB) ( 639 )   The effects of the additive CaF2 and preheating temperature of mold on the SHS reaction by which the CuCr alloy was prepared and its properties were investigated. The metallographic structure of CuCr alloy and its chemical composition were analyzed, with the CuCr alloy and slag characterized by XRD. Experimental results indicated that the alloy consists of both Cu-rich and Cr-rich zones, and no new eutectic phase was found though there are Cu and Cr phases. The slag mainly consists of Al2O3, and the additive CaF2 and high preheating temperature can improve the efficiency of separating metal from slag. The forced water cooling can constrain efficiently the macrosegregation. When the ratio of the additive CaF2 is 10wt% and the preheating temperature is 500°C with forced water cooling, the homogeneous and compact CuCr alloy can be prepared. References | Related Articles | Metrics

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Study on optical rotation of polymer dispersed chiral liquid crystal Wang, Jian-Hua (1); Zhang, Bao-Yan (1); Liang, Guang-Xu (1); Li, Ming-Chao (1) 2009, 30 (10):  1466-1468.  DOI: - Abstract ( 319 )   HTML   PDF (214KB) ( 997 )   The chiral polymer dispersed liquid crystal (PDLC) was fabricated by free radical polymerization under the action of photoinitiator by ultraviolet iradiation. The morphology and effect of temperature on optical rotation in chiral PDLC film were discussed via POM and polarimeter respectively. The trifunctional pre-polymer TMPTA which is available to quick polymerization was selected to obtain the dispersion of liquid crystal droplets in micrometer size. As a result, the effect of temperature on optical rotation through the measurement by polarimeter conforms to the theory of de Vries. Such distinctive optical properties as opticity and selective reflection of chiral agent-doped PDLC have widely been applying in the field of light filter, grating, and reflective display, etc. References | Related Articles | Metrics

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Synthesis and properties of chiral liquid crystal polymers containing donor-acceptor He, Xiao-Zhi (1); Zhang, Lin (1); Zhang, Bao-Yan (1); Mu, Qiang (1) 2009, 30 (10):  1469-1472+1488.  DOI: - Abstract ( 256 )   HTML   PDF (428KB) ( 622 )   The electron-donating chiral monomer 2-(4-allyloxy benzoate)-5-{[4-(4-propoxy)phen-yl] phenyloxycarbonyl} pentanoic acid isosorbide (M1) and the electron-accepted liquid crystal monomer 4-(10-undecylen-1-yloxycarbonyl)benzoic acid biphenyl cyanogen (M2) were grafted onto the backbone of polymethylhydrosiloxane (PMHS). The mesomorphic properties of cholesteric liquid crystalline polymers P1~P8 containing different contents of M1 from 0 to 50 mol% were investigated by FTIR, 1HNMR spectra, DSC, POM, TG and X-ray. Experiment results showed that P1~P8 are the thermotropic cholesteric liquid crystal polymers and that glass transition temperature tg increases and isotropic temperature ti decreases with the increasing content of M1 and the mesomorphic temperature ranges of the polymers are wider. The thermal stability of the polymers is about 300°C with only 5 wt% lost. References | Related Articles | Metrics

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Stability research of synchronous operation of dual-motor driven vibrating system Wang, De-Gang (1); Zhao, Qing-Hua (2); Zhao, Chun-Yu (1); Wen, Bang-Chun (1) 2009, 30 (10):  1473-1476.  DOI: - Abstract ( 269 )   HTML   PDF (2317KB) ( 495 )   To investigate the stability of synchronous operation of a dual-motor driven vibrating system, a dynamic model of the system is developed for non-linear dynamic analysis. By the dimensionless processing of system parameters, a frequency capture equation of the vibrating system and the conditions for implementing the stable self-synchronous operation are obtained to calculate the stability domain of self-synchronous operation. Then, the vibrating system is optimally designed according to the conditions for stability and stability domain to regulate the system parameters. The computer simulation results showed that the vibrating system implements both the speed synchronization and phase synchronization, thus making the self-synchronous state stable. The correctness of the conditions for stability and stability domain of self-synchronous operation has been verified, as well as the effectiveness of the optimal design. References | Related Articles | Metrics

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Cophase and synchronous characteristic of vibration machine under electromechanical coupling condition Zhang, Nan (1); Hou, Xiao-Lin (2); Wen, Bang-Chun (1) 2009, 30 (10):  1477-1480.  DOI: - Abstract ( 291 )   HTML   PDF (1437KB) ( 577 )   A self-synchronous vibrating machine with cophase rotation was put forward. Based on the Lagrange equation of dynamics, a dynamic model was deduced for the machine with an electromechanical-coupling model developed. Then, the parameter relevant to the machine were analyzed quantitatively under electromechanical-coupling conditions and investigated experimentally. Combining a simulation with experiments, the reproducibility of cophase and synchronous characteristics of the vibrating machine was revealed under electromechanical-coupling conditions. The results show that the stably synchronous operation can be implemented only if the machine satisfies theoretically the synchronization condition for vibrating machines. References | Related Articles | Metrics

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Numerical simulation of circulating flow field structure in RH-refining process Wang, Xiao-Dong (1); Wang, Wei-Na (1) 2009, 30 (10):  1481-1484.  DOI: - Abstract ( 474 )   HTML   PDF (733KB) ( 1198 )   A two-phase flow mathematic model based on Eulerian-Eulerian approach was developed to investigate the flow behavior of the Ruhrstahl Heraeus (RH) degassing process driven by bubbles. The liquid velocity distribution in vacuum chamber/ladle was simulated numerically by the CFD (commercial computational fluid dynamics) code FLUENT 6.0, and it was found that the theoretically simulated results of flow behavior in vacuum chamber/ladle conforms basically to the experimental results. Analyzing the structure of such a flow field, several swirling zones are found separated from the main circulating flow in vacuum chamber/ladle, which could reduce the circulating efficiency in refining process on the whole. The optimization of geometric and gas-charging parameters of RH system and matching them well in design will be crucial to improving the circulating flow field structure and recycling efficiency. References | Related Articles | Metrics

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Application of jet-pipe electrohydraulic servovalve to temperature control of aeroengine Wang, Zhao-Ming (1); Qu, Li-Peng (3); Zhang, Dong (2); Ba, De-Chun (1) 2009, 30 (10):  1485-1488.  DOI: - Abstract ( 357 )   HTML   PDF (346KB) ( 777 )   Gas temperature is crucial to aeroengine, since it directly affects the performance and service life of the latter. For instance, a direct regulating valve was once used in the temperature control system of a certain aeroengine to constrain gas temperature, which resulted in an unideal state of system performance due to its low precision. To solve the problem, an improvement scheme is proposed, i.e., a jet-pipe electrohydraulic servovalve is used instead of the direct regulating valve for gas temperature control. Testing and commissioning results showed that the jet-pipe electrohydraulic servovalve has the advantages of high control precision, low hysteresis loop and high stabilization under low pressure, thus improving remarkably the system performance to satisfy the requirements of the aeroengine with high feasibility. References | Related Articles | Metrics

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Research on selective grinding of low-grade bauxite in vibration mill Han, Yue-Xin (1); Zhu, Yi-Min (1); Tian, Yi-Lan (1); Wang, Ze-Hong (1) 2009, 30 (10):  1489-1492.  DOI: - Abstract ( 252 )   HTML   PDF (429KB) ( 579 )   The selective grinding in vibration mill for bauxite whose components ratio in fraction of w(Al2O3)/w(SiO2)=4.4 was investigated via tests. The results showed that component ratio of coarse-particle bauxite ground is comparatively higher if its mass fraction in pulp is 70%, which means a better selectivity. And if the mass ratio of ground material to grinding ball is 0.9, the selective grinding will have a good effect. As to the type of grinding, wet grinding has better selective effect than dry grinding. Under the favorable conditions as above, the component ratio w(Al2O3)/w(SiO2) of ground product (particle size >+0.23 mm) is over 7.5 with the output rate 25% and recovery rate 27% of Al2O3. Desilication of low-grade bauxite by selective grinding is feasible. References | Related Articles | Metrics

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Suppression mechanism of Thiobacillus ferrooxidans as biosorbate for reducing floatability of pyrite Liang, Hai-Jun (1); Wei, De-Zhou (2) 2009, 30 (10):  1493-1496.  DOI: - Abstract ( 331 )   HTML   PDF (143KB) ( 738 )   Zeta potential and surface contact angle of pyrite were measured before and after adsorbing Thiobacillus ferrooxidans onto pyrite surface to examine its change in electrical properties and wettability, and the suppression mechanism of Thiobacillus ferrooxidans as biosorbate for reducing the floatability of pyrite during froth floatation was discussed. The results showed that after interacting with Thiobacillus ferrooxidans the surface electrical properties of pyrite change obviously to result in the reduction of pH value at iso-electric point, but its surface wettability varies slightly. The suppression effect of Thiobacillus ferrooxidans as biosorbate onto pyrite surface does not result from increasing its surface hydrophilicity but from weakening the attachment of collector to pyrite particles during froth floatation. Electrostatic interaction and steric hindrance are the main causes of the suppression of pyrite floatability. References | Related Articles | Metrics

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Mechanism and design method of a dust cleaning system: Rotary blowback bag filter Hao, Wen-Ge (1); Shi, Wei (2); Ding, Shu (1); Zhu, Na (1) 2009, 30 (10):  1497-1500.  DOI: - Abstract ( 278 )   HTML   PDF (311KB) ( 1133 )   A design method was proposed for the rotary blowback bag filter, based on the understanding of its dust cleaning mechanism in depth. The flow field caused by blowback airflow in the bag was investigated theoretically and experimentally, with a test done on the Φ100 mm × 6000 mm model of bag filter and a method presented to determine the flowrate and pressure of blowback airflow. The results showed that the filtered dust cake on the bag filter surface will form a resistance to the radial blowback airflow, i.e., there is a proper correlation between the force resulting from airflow to peel off the dust cake and dust peel-off rate. References | Related Articles | Metrics

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Game theory-based analysis of trust during the formation of R&D alliances between enterprises Yu, Chun-Hai (1); Fan, Zhi-Ping (1); Zhou, Wen-Guang (1) 2009, 30 (10):  1501-1503+1507.  DOI: - Abstract ( 382 )   HTML   PDF (194KB) ( 673 )   Aiming at the fact that the R&D alliances between enterprises prevail nowadays but many of them have disintegrated before they came into expected effect, an analysis was made for the influence of trust on those R&D alliances via the game theory. With the concepts of trust and such R&D alliance ascertained, the influence of trust on the formation of such R&D alliances was discussed in relation to the three factors substitution rate of products, enterprise's learnability and rate of technology spillover. The results indicated that when the trust is firm, the enterprises ally with each other for R&D; when the trust is medium, either cunning or alliance is possible, depending on the three factors; when the trust is weak, an enterprise tends to do R&D individually. References | Related Articles | Metrics

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Quantity discount policy based on trade credit for supply chain coordination Yu, Li-Ping (1); Huang, Xiao-Yuan (1) 2009, 30 (10):  1504-1507.  DOI: - Abstract ( 267 )   HTML   PDF (750KB) ( 555 )   In a supply chain from a supplier to a retailer, the trade credit the former offered to the latter is possible to affect individually their target profit hence the total profit of the supply chain. To solve the problem, the total income from the supply chain should be shared rationally between the supplier and retailer, thus developing a contractual coordination model for quantity discount based on trade credit in random demand. Analyzing the effect of quantity discount policy on income sharing and coordination on the basis of a certain trade credit, the optimal contractual parameters are deduced to realize the coordination of the whole supply chain. A numerical example is given to demonstrate the correctness of the conclusion drawn from the coordination model and relevant analysis. References | Related Articles | Metrics

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Gray correlation evaluation of CSR in view of employer-employee relation in China Zhang, Lan-Xia (1); Li, Zheng (1); Yuan, Dong-Nan (1); Zhang, Ming-Jiao (1) 2009, 30 (10):  1508-1512.  DOI: - Abstract ( 267 )   HTML   PDF (206KB) ( 755 )   Describing briefly the adaptability of method selection in combination with the findings of some earlier works, interviews and questionnaires, a corporate social responsibility (CSR) evaluation index system was framed to investigate the employer-employee relation in China, including 6 1st -level and 42 2nd-level indexes. The system was composed of the contracts based on CSR index in both explicit and implicit forms. Then, a CSR evaluation model for employer-employee relation was developed on the basis of the analysis of gray correlation, with which how some commercial banks in China did their CSRs were evaluated to show the effectiveness of the proposed method. References | Related Articles | Metrics

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Dual-objective pricing strategy of e-commerce retailer Li, Li-Jun (1); Liu, Ting-Ting (1) 2009, 30 (10):  1513-1515+1520.  DOI: - Abstract ( 316 )   HTML   PDF (167KB) ( 672 )   Long-time and amicable relationship between customers and retailers is crucial to the development of the latter. Considering the current profit and future development, an e-commerce retailer shouldn't take the profit any longer as the only objective, but take the customer satisfaction as another important objective simultaneously. According to the evaluation of customer satisfaction by P-E model and questionnaire, the objective function of customer satisfaction was given with a dual-objective pricing model developed in e-commerce via optimization. A numerical example was thus analyzed comparatively and the results showed that under the dual-objective strategy, the more a retailer makes much of profit, the higher the price tends to. However, the price and profit under dual-objective strategy are always not higher than the price and profit under single-objective strategy. If the satisfaction from quality and service remain unchanged, the higher the price, the lower the customer satisfaction. So, the study on the dual-objective pricing strategy is of instructive significance to e-commerce retailers. References | Related Articles | Metrics

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Research on pollution discharge evaluation based on information entropy and unascertained measure a case study of liaoning province Hu, Wang-Yang (1); Ren, Rong-Rong (2); Xing, Gang (2); Yang, Xi-Huai (1) 2009, 30 (10):  1516-1520.  DOI: - Abstract ( 271 )   HTML   PDF (234KB) ( 515 )   Information entropy theory was introduced into the investigation on waste discharge evaluation indexes in a macroscopic view of the recycling economic system, where the index system was reduced via quantifying the entropy measure. Then a comprehensive evaluation was done for waste discharge through the unascertained measure model. The information entropy algorithm was used to determine the weights of evaluation indexes so as to exclude man-made interference for more accurate recognition results. The data of waste discharge in Liaoning Province measured from 2001 to 2007 were cited to verify the feasibility and effectiveness of the unascertained measure model. References | Related Articles | Metrics