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15 September 2014, Volume 35 Issue 9 Previous Issue    Next Issue
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Information & Control

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FaultTolerant Control for a Class of Markov Jump Systems with Actuator Failures FAN Quanyong， YE Dan 2014, 35 (9):  1217-1220.  DOI: 10.12068/j.issn.1005-3026.2014.09.001 Abstract ( 848 )   HTML   PDF (440KB) ( 652 )   The problem of adaptive faulttolerant control was studied for a class of Markov jump linear systems with partly known transition probabilities. The considered transition probabilities were more general， in which the completely known case， partly unknown with known lower and upper bounds case and completely unknown case were all included. Firstly， the adaptive fault estimator was designed for actuator degradation. Then， based on the values estimated online， the robust controller with compensation effect was designed to guarantee the robust stability of the system with faults. At the same time， the freeconnection weighting matrix method was used to deal with the unknown transition probabilities so that the proposed sufficient conditions were less conservative. Finally， numerical example was given to demonstrate the effectiveness of the proposed method. References | Related Articles | Metrics

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Dynamic Hierarchical Fault Diagnosis of Intelligent Power Network Based on the Multisource Information LIU Xinrui， XU Guojun， YE Jinfeng， ZHANG Jing 2014, 35 (9):  1221-1224.  DOI: 10.12068/j.issn.1005-3026.2014.09.002 Abstract ( 656 )   HTML   PDF (691KB) ( 554 )   Considering the complicated structure and the diversified information system of intelligent power network， a novel method for fault diagnosis was proposed. In the proposed method there were three parts including switch layer used for the simple fault diagnosis， feeder layer strived to resolve complex fault in the case of abnormal switch and protection information， and substation layer used to judge multitype fault in the complex system. Simultaneously， dynamic diagnosis strategy was adopted to adjust diagnostic entrance and structure longitudinally. And the improved depthfirst searching algorithm， Petri net reasoning and intuitionistic uncertaintyrough sets theory were applied to each layer respectively in the diagnosis. The simulation results showed that the adaptability of each layer diagnosis is enhanced， and the efficiency and accuracy of fault diagnosis are improved.In addition， kinds of complex fault can be accurately diagnosed with good practical application value. References | Related Articles | Metrics

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Exponential Stability for Linear Systems with Interval TimeVarying Delays ZHENG Lianwei， SONG Shuni 2014, 35 (9):  1225-1228.  DOI: 10.12068/j.issn.1005-3026.2014.09.003 Abstract ( 611 )   HTML   PDF (299KB) ( 526 )   Based on the Lyapunov functional， exponential stability for linear systems with timevarying delay was studied. The time delay is a differentiable function belonging to a given interval. A new criterion for exponential stability was proposed in the form of linear matrix inequalities. When the derivative of the Lyapunov functional was estimated， a tighter upper bound was obtained using convex combination and reciprocally convex combination approaches that led to less conservatism of the condition for exponential stability.In addition， the obtained exponential upper bound of the state depended only on the initial function itself. An example was then presented to show the effectiveness of the proposed method. References | Related Articles | Metrics

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Comparison of Firing Mechanisms of Neuron Model Adaptability Under External Alternating Electric Field YUAN Chunhua， WANG Jiang 2014, 35 (9):  1229-1233.  DOI: 10.12068/j.issn.1005-3026.2014.09.004 Abstract ( 760 )   HTML   PDF (677KB) ( 899 )   Spikefrequency adaption is a prominent feature of neuronal dynamics. It plays an important role in neuronal information processing. To investigate the different mechanisms of spikefrequency， two kinds of modified leaky integrateandfire models(LIF models)under external alternating electric field were established. The curves of the onset spike frequency and the spikefrequency of the steady state were analyzed. The LIFAC shifted the frequency curves to higher inputs without affecting its slope， and the LIFDT had a divisive effect on the frequency curves. The spike frequency of the steady state was linear under the external alternating electric field. The effects of external alternating electric field on different kinds of adaption mechanisms were also analyzed by the correlation and the variability between consecutive interspike intervals. References | Related Articles | Metrics

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Design of Outsourcing Contract Considering the Risk Attitude of Both Sides with Asymmetric Information CHEN Kegui， HUANG Min， MENG Fanli， WANG Xingwei 2014, 35 (9):  1234-1238.  DOI: 10.12068/j.issn.1005-3026.2014.09.005 Abstract ( 619 )   HTML   PDF (547KB) ( 693 )   The outsourcing contract design with both moral hazard and adverse selection was investigated under different risk attitude combination between the client and the provider. Based on the principalagent theory， the contract was designed which was used by the client to motivate the provider’s participation and screen its true private information. Furthermore， the impact of the asymmetric information and risk attitude combination on the corresponding optimal strategies and expected profit were analyzed. The analysis results showed that with dual asymmetric information， the optimal strategies and expected profit of both sides were depended on the risk attitude combination as well as the asymmetric information. The above results also implied the impact of the risk attitude on the decisions of both sides as well as the value of information， and provided the decision support for the outsourcing contract design. References | Related Articles | Metrics

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Modified Artificial Bee Colony Algorithm Based on Subpopulations LIU Hongzhi， GAO Liqun， KONG Xiangyong， YANG Fading 2014, 35 (9):  1239-1243.  DOI: 10.12068/j.issn.1005-3026.2014.09.006 Abstract ( 640 )   HTML   PDF (822KB) ( 586 )   Due to the shortcomings of the artificial bee colony(ABC)algorithm and the existing improved algorithms， a new modified ABC algorithm was proposed based on the subpopulations(SPABC). In this algorithm， the population was divided into two subpopulations according to the comparison between the individual fitness value and the mean of population fitness values， and the different search method was adopted in the different subpopulations to effectively balance exploration and exploitation capability. In addition， the initial solutions were generated by piecewise Logistic equation to enhance the convergence speed of the algorithm. Compared with ABC algorithm and other modified ABC algorithms， the numerical simulation results demonstrated that the proposed algorithm has better optimization accuracy and convergence speed in solving complex numerical optimization problems. References | Related Articles | Metrics

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A Multihop Information Broadcast Protocol in Distributed Vehicular Networks ZHAO Hai， TIAN Tingting， FAN Jingchao， LIU Peng 2014, 35 (9):  1244-1248.  DOI: 10.12068/j.issn.1005-3026.2014.09.007 Abstract ( 847 )   HTML   PDF (491KB) ( 724 )   In traditional vehicular networks， most of the information transmissions were conducted by mobile cellular networks. One of the shortcomings of transmissions with cellular networks is the very long delay time， and consequently it is not applicable to realtime alarm information.However， in broadband wireless networks， the endtoend delay of alarm information delivered through multihop broadcast transmission can be greatly decreased. According to the characteristics of vehicular networks， a transmitteroriented AMBP(alternating multihop broadcast protocol)was proposed on the basis of geographical position. In the protocol， the next hop relaying node was selected by a vehicle and the alternate transmission threshold value was calculated with the neighbor information that was kept in its neighbor vehicle table. Finally， different transmission policies were taken by the proposed AMBP based on the relationships between packet size and the transmission threshold value. Experimental results showed that packet loss rate， transmission delay， and delay jitter can be successfully reduced by the proposed AMBP， which demonstrates that it is more suitable for distributed vehicular communication environment. References | Related Articles | Metrics

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Joint Analysis Method of Multiple Search Behaviors ZHANG Yin， GAO Kening， ZHANG Bin 2014, 35 (9):  1249-1252.  DOI: 10.12068/j.issn.1005-3026.2014.09.008 Abstract ( 642 )   HTML   PDF (354KB) ( 633 )   Aiming at the fact that available search behavior analysis methods could only analyze one single type of search behavior， which leads to the problems that the user interest could not be effectively get， a joint analysis method of multiple search behaviors was proposed. By combining the analysis of page dwell time， mouse click times，page revisit times and slider move times using M5 model， clues from more angles other than one single type of user behavior were gained for user interest analysis， and joint analysis of high dimension data composed of multiple user behaviors was realized with timeliness ensured for online behavior analysis. Experiment results show that the proposed method can analyze the behaviors better than compared approaches. References | Related Articles | Metrics

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Blind Multiuser Detection Based on Complex FastICA Algorithm LIU Xiaozhi， SHAO Xiu，YANG Yinghua， CHEN Xiaobo 2014, 35 (9):  1253-1257.  DOI: 10.12068/j.issn.1005-3026.2014.09.009 Abstract ( 862 )   HTML   PDF (402KB) ( 1303 )   A new blind multiuser detection algorithm was proposed on the basis of complex FastICA in MIMOOFDM system. With the proposed algorithm， the separation of multiuser could be speeded up by fast convergence characteristics of complex FastICA algorithm firstly， and the indeterminacy of amplitude and indeterminacy of phase by CFastICA algorithm were revised by using correlation function. At last， comparing the improved algorithm with the complex natural gradient learning algorithm(CNGLA)， it was proved that CFastICA algorithm has not only faster convergent speed but also smaller bit error rate. It also indicated that using more numbers of receiving antennas would get better signal separation. Related Articles | Metrics

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Texture Synthesis Method Based on Pixel Adaptive Neighborhood WANG Zhan， YAN Yunhui， SONG Kechen 2014, 35 (9):  1257-1260.  DOI: 10.12068/j.issn.1005-3026.2014.09.010 Abstract ( 686 )   HTML   PDF (1002KB) ( 883 )   A novel method that can automatically confirm the best neighborhood size of pixel matching was proposed to improve the narrow application range of traditional pixelbased texture synthesis. Firstly， texton was extracted using block truncation coding， and the best neighborhood size of pixel matching was confirmed by the texton. Then， the norm of pixel matching was improved in the matching stage. By comparing the mean values and variance of sample pixels and target pixels， neighborhood similarity and optimal pixel can be deternined. The results show that the proposed method can generate good synthesis and has a wide application range， and thus can be a universal texture synthesis technology. References | Related Articles | Metrics

Materials & Metallurgy

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Microstructure and Mechanical Property Evolution of MgZnGd Alloy with Different Initial States During Processing DING Yunpeng， LE Qichi， ZHANG Zhiqiang， CUI Jianzhong 2014, 35 (9):  1262-1265.  DOI: 10.12068/j.issn.1005-3026.2014.09.011 Abstract ( 792 )   HTML   PDF (1980KB) ( 686 )   The asrolled and asannealed Mg2%Zn1%Gd sheets were processed by 66% rolling at 360℃ and subsequent annealing. The microstructure and mechanical property evolution during processing were studied. The specimens were examined by optical microscopy， tensile test and Erichsen test. The results indicated that during processing， the mechanical property evolution of MgZnGd sheets with different initial state is different， depending on shear band， twin density and grain size. After the whole thermalmechanical processing， the asannealed sheet with the elongation rate of 289% has a better mechanical property and a lower mechanical anisotropy， compared with those of the asrolled sheet. The asannealed sheets also exhibit better formability at room temperature. References | Related Articles | Metrics

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Physical Simulation of Fluid Mixing in a Smelting Reduction IronBath with Thick Slag Layer LI Chengzhi， HE Yibo， LI Qiang， ZOU Zongshu 2014, 35 (9):  1266-1270.  DOI: 10.12068/j.issn.1005-3026.2014.09.012 Abstract ( 535 )   HTML   PDF (773KB) ( 683 )   An ironbath reactor with thick slag layer for smelting reduction was designed， and the influences of blowing parameters on bath mixing time were studied with a water model. The results showed that using singlenozzle bottom blowing， the influences of middle lance inclination angle and immersion depth and lower lance inclination angle are smaller and the influence of lower lance immersion depth is greater， compared with side blowing only. The mixing time with twonozzle bottom blowing is shorter than that with fournozzle bottom blowing. With the same number of bottom nozzles， the mixing time with asymmetric nozzle layout is shorter than that with symmetric layout. Comparing the mixing time of the six optimum blowing combinations， the asymmetrical twonozzle bottom blowing is the best combination for the reactor， and the corresponding optimum side blowing is as follows: 50° inclination angle， 180mm immersion depth of middle lance and 50° inclination angle， 180mm immersion depth of lower lance. Related Articles | Metrics

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Dynamic Evolution of Inclusions in AlMg Deoxidation Melts ZHANG Tongsheng， WANG Deyong， ZHANG Yongqi， JIANG Maofa 2014, 35 (9):  1270-1274.  DOI: 10.12068/j.issn.1005-3026.2014.09.013 Abstract ( 742 )   HTML   PDF (765KB) ( 1043 )   The inclusions characteristics and dynamic evolution of hightemperature experimental melts with different S and O content were studied by using SEMEDS and CSLM. The results showed that most of MgO in the deoxidation melt is spherical， but the MgO·Al2O3 presents irregular shape. Large inclusions of Al2O3 is easy to form in Alkilled molten steel through travelling， collision and aggregation. However， the characteristics of inclusions in AlMg complex deoxidation melts are different， depending on the content of［Al］，［Mg］and［S］. When the content of ［Mg］ and ［Al］ meets the condition of MgO， the inclusions show no obvious aggregation tendency， even have isolated and dispersed distribution. When the content of ［Mg］ and ［Al］ meets the condition of MgO·Al2O3， the inclusions also show no obvious aggregation tendency， but the size of single particle is larger than that of MgO particles. When the content meets the formation condition of MgO and MgS simultaneously， the aggregation tendency of the inclusions is obvious. It is easily speculated that the sulphides promote the aggregation of the inclusions. References | Related Articles | Metrics

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Development and Properties Research of TinContaining Ferritic Stainless Steel HAN Jipeng， LI Yang， JIANG Zhouhua， FANG Yong 2014, 35 (9):  1275-1278.  DOI: 10.12068/j.issn.1005-3026.2014.09.014 Abstract ( 775 )   HTML   PDF (540KB) ( 1045 )   The mechanical properties， the corrosion resistance and the effect of Sn on the microstructure of the Sncontaining ferritic stainless steel matrix were studied on the basis of the metallurgical reaction equilibrium of the smelting process. The morphology and composition evolution of the deoxidization inclusions were analyzed. The results showed that the yield of tin is pretty high in consideration of its low melting point. The enrichment of tin around the sulfide inclusions is observed in scanning electron microscope. The new type ferritic stainless steel has better corrosion resistance than SUS 430 stainless steel， and the excellent plasticity and strength which can meet the requirement of deep drawing process. Therefore，it can substitute partly the application of SUS 430 in the industrial production. References | Related Articles | Metrics

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Numerical Simulation of An Adjustable Length of Flame Gas Burner FENG Mingjie， LI Deli， WANG Engang 2014, 35 (9):  1279-1282.  DOI: 10.12068/j.issn.1005-3026.2014.09.015 Abstract ( 744 )   HTML   PDF (548KB) ( 905 )   The effects of thermal load and the ratio(β)of centre and outring fuel flow on the length of flame and temperature field in a combustion chamber were studied by a numerical models of an adjustable length of flame gas burner on the platform of Fluent 63. The results indicated that changing the β of the burner can adjust the length of flame and the temperature field in the combustion chamber under a constant thermal load. The temperature field and the highest temperature in the combustion chamber under a constant thermal load change with the different β. The front high temperature zone gradually shrinks， while the back high temperature zone gradually expands and moves forward with the increasing of β. The length of flame changes short or long with the increasing of β when β<05 or β>05， respectively， and it is the shortest when the β is 05. References | Related Articles | Metrics

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Solid Boronizing on the Surface of Pure Titanium TA1 and Titanium Alloy TC4 LI Fenghua， DONG Mengge， WANG Lina， FAN Zhanguo 2014, 35 (9):  1284-1288.  DOI: 10.12068/j.issn.1005-3026.2014.09.016 Abstract ( 806 )   HTML   PDF (835KB) ( 788 )   The solid powder boronizing， on the surface of titanium alloys with matrix structure αTi of TA1 and(α+β)Ti of TC4， was investigated. The morphology of boride layer was observed by polarizing microscope and scanning electron microscope(SEM). The phase composition of boride layer was analyzed by Xray diffraction(XRD). The results show that when boronizing temperature is in the range of 850~1000℃， diffusion layers on TA1 in a multilayer structure are paralleled to the surface of the substrate， which composes of Ti3O and TiB phases. When the temperature is higher than 920℃， TiB becomes the major component in the diffusion layer with TiB2， and the content of titanium borides increases with temperature. When the temperature is lower than 1000℃， Ti3O and TiB are the major components of the layer on TC4. When it is higher than 1000℃， the layer is TiB2 and TiB whisker. Boronizing temperature above 1000℃ is the sufficient condition for the formation of titanium borides. References | Related Articles | Metrics

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Oxygen Pressure Leaching of Converter Vanadium Slag by Titanium Dioxide Waste Without Roasting ZHAO Hongliang， ZHANG Guoquan， LYU Guozhi， ZHANG Tingan 2014, 35 (9):  1288-1290.  DOI: 10.12068/j.issn.1005-3026.2014.09.017 Abstract ( 740 )   HTML   PDF (506KB) ( 675 )   The process of oxygen pressure leaching of converter vanadium slag with titanium dioxide waste without roasting was researched. Thermodynamic analysis indicates that: soluble vanadium ions are stable in the acid solution. Leaching experiments show that the initial acid concentration is the most important factor in the leaching process. Under the conditions: leaching temperature 150℃， leaching time 40min， liquid to solid ratio 12∶1(ml·g-1)， initial acid concentration 250g·L-1， oxygen pressure 02MPa， the vanadium leaching rate is 9851%. The XRD patterns of leaching residues under different conditions show that with the increase of vanadium leaching rate， the vanadium spinel phase is gradually disappeared and ilmenite phase is transformed into anatase phase in the leaching residue. References | Related Articles | Metrics

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Effect of F on Sintering and Leaching Properties of Calcium Aluminate in CaOAl2O3SiO2 System DONG Kaiwei， YU Haiyan， PAN Xiaolin， BI Shiwen 2014, 35 (9):  1292-1296.  DOI: 10.12068/j.issn.1005-3026.2014.09.018 Abstract ( 812 )   HTML   PDF (811KB) ( 500 )   Calcium aluminate clinker containing different contents of F in CaOAl2O3SiO2 system was obtained with analytically pure reagents as raw materials. The selfdisintegrating property， sintering and leaching properties of the clinker were studied by XRF， XRD and SEMEDS methods. The results indicate that β2CaO·SiO2 converts into γ2CaO·SiO2 normally when clinker contains F， which has little effect on the selfdisintegrating property of clinker. But F has significant effects on the phase composition of calcium aluminates. F promotes the formation of 2CaO·Al2O3·SiO2 and 11CaO·7Al2O3·CaF2 while reduces the formation of 12CaO·7Al2O3 and CaO·Al2O3. The Al2O3 leaching rate reduces with 2CaO·Al2O3·SiO2 entering into clinker. The Al2O3 leaching rate of clinker decreases from 9501% to about 70% when the F addition increases from 0 to 20%. The content of F should be less than 05% in the clinker. References | Related Articles | Metrics

Mechanical Engineering

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Identification Method of Local Dynamic Parameters Based on FEM TAN Zhen， LI Chaofeng， TAI Xingyu， WEN Bangchun 2014, 35 (9):  1296-1299.  DOI: 10.12068/j.issn.1005-3026.2014.09.019 Abstract ( 775 )   HTML   PDF (553KB) ( 576 )   Based on the finite element theory， an theory equation which can be adapted to identify parameters of stiffness and damping was derived by harmonic balance method. The equation was solved by in the form of trigonometric function(sine， cosine)and plural respectively. A typical rotor system case was simulated to check the supporting stiffness and damping of subsystems. The results show that both kinds of forms can identify boundary parameter accurately and reliably. But the forms of sine and cosine expansions are so complicated after derivation that it is unfit for identification of the system nonlinear characteristics. The form of plural expansion can simplify the process of calculation and deduction， and it can well identify both the linear solution and nonlinear solution with higher precision. This study can provide theoretical reference for design and vibration analysis of such systems. References | Related Articles | Metrics

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Dynamic Model of the Transmission System in Wind Turbine Gearbox ZHOU Shihua， LI Chaofeng， WANG Kaiyu， WEN Bangchun 2014, 35 (9):  1301-1305.  DOI: 10.12068/j.issn.1005-3026.2014.09.020 Abstract ( 1136 )   HTML   PDF (735KB) ( 1442 )   Due to the random characteristics of wind speed， the transmission system in wind turbine gearbox would produce complex vibration， which can cause internal structure fatigue of the drive system. In order to analyze the performance of the gearbox， the wind turbine gearbox system was divided into threeclass gear transmission， and the dynamical models of spur gear， helical gear and planetary gear were built. On this basis， the dynamical model of the whole wind turbine gearbox system was established. The vibration differential equations of the drive system were derived through the Lagrange’s equation， considering the meshing stiffness， meshing damping， comprehensive meshing error， eccentricity， gravity， bendingtorsional coupling and support bearing. The model provides some theoretical reference for the characteristic analysis and vibration control of similar wind turbine gearbox system. References | Related Articles | Metrics

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Multi Degrees of Freedom Dynamic Analysis and Calculation on Hoisting System of Mechanical Excavator LIN Guiyu， LI Jie， ZHAO Jun， XU Yuming 2014, 35 (9):  1306-1311.  DOI: 10.12068/j.issn.1005-3026.2014.09.021 Abstract ( 1210 )   HTML   PDF (518KB) ( 586 )   According to the thoughts of the system theory， taking the driving moment of hoisting system as generalized force， a dynamic model of elastomer and rigid body with many freedom degrees for hoisting system was established using the dynamic theory and Lagrange equation method. The vibration response of hoisting system was calculated based on the matrix iterative method under conditions of locked rotor and vertical boom spreading of bucket rod. The calculated dynamic load coefficient of the highspeed shaft and the hoisting rope is 1343 and 1374， respectively. The effects of lockedrotor time and soil stiffness on the dynamic load of hoisting system were analyzed and accordingly the dynamic load coefficients with different soil stiffness were obtained. To reduce dynamic load and ensure the safe functioning of device， the lockedrotor time should not be more than 20s. Related Articles | Metrics

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Drag Torque Analysis of Friction Plates with Different Grooves for Tracked Vehicles WANG Yanzhong， WEI Bin， NING Keyan， HAN Ming 2014, 35 (9):  1311-1314.  DOI: 10.12068/j.issn.1005-3026.2014.09.022 Abstract ( 734 )   HTML   PDF (1069KB) ( 697 )   In order to simulate the viscous drag losses for tracked vehicles， the drag torques of the friction pairs with three common grooves， radial slot， double circular groove and spiral groove， were analyzed using theory and experiment methods. The applicable situations and torque characteristics with the friction pairs of different grooves were simulated using the drag theory and CFD models. The effect of gap and rotating speed on the drag torque of the friction pair was analyzed. The result shows that the torque characteristics of friction plates with spiral grooves are strongly correlated with the directions of rotation and thus the friction pair of spiral groove has advantage in decreasing viscous losses when heat dissipation is not considered. References | Related Articles | Metrics

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Design and Analysis of CombShaped Flexure Joint QIU Lifang， MENG Tianxiang， ZHANG Jiuqiao， YANG Debin 2014, 35 (9):  1316-1320.  DOI: 10.12068/j.issn.1005-3026.2014.09.023 Abstract ( 708 )   HTML   PDF (2175KB) ( 928 )   A new combshaped flexure joint was proposed and designed in lamina emergent mechanisms. The equivalent stiffness of the combshaped flexure joint was deduced.Using theoretical calculation and finite element simulation analysis of the design example， the correctness of the calculation formula and simulation models was verified. Meanwhile， the equivalent stiffness could maintain a linear relationship even in large angular displacement. The strength of the example had been checked under the maximum angular displacement of the joint.Torsion stiffness of the joint was also simulated and analyzed. The bending stiffness of the example was compared among the combshaped flexure joint， ITLEJ joint and LET joint. References | Related Articles | Metrics

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Load Measurement and Analysis of Aluminum Alloy Refill Friction Stir Spot Welding REN Jungang， XIE Liyang， WANG Lei， GUO Lipeng 2014, 35 (9):  1321-1323.  DOI: 10.12068/j.issn.1005-3026.2014.09.024 Abstract ( 566 )   HTML   PDF (447KB) ( 656 )   The Zaxis loads were measured in the process of 6082T6 aluminum alloy refill friction stir spot welding and the influence of different welding parameters(shaft shoulder rotate speed， stirring pin rotate speed， tying into/withdrawing time and tying into depth， etc.)on loads was studied. The results show that curve of loads in the process of aluminum alloy refill friction stir spot welding can be divided into 4 zones: clamp ring pushing process， shaft shoulder tying into process， stirring pin refill process and stirring tool unloading process. Loads in the test reduce fluctuation as the rotating speed of shaft shoulder or stirring pin increases. Loads in the test reduce gradually as the shoulder tying into/withdrawing time increases. Loads in the test fluctuate without showing a trend as the shoulder tying into depth increases. References | Related Articles | Metrics

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Unsteady Lubrication Film Characteristics at Rolling Interface FU Kuo， ZANG Yong， GAO Zhiying 2014, 35 (9):  1324-1327.  DOI: 10.12068/j.issn.1005-3026.2014.09.025 Abstract ( 611 )   HTML   PDF (439KB) ( 581 )   Based on hydrodynamics， rolling theory， and characteristics curve solution of Hill differential equation， a dynamic model of unsteady film thickness distribution at the rolling interface was constructed. The model considered the fluctuation of the inlet strip thickness and the roll radius. The film wave coefficient was proposed to reflect the absolute fluctuation of film thickness. The corresponding simulation and analyses were also carried out. The results show that the film thickness distribution and the thinnest film thickness are timedependent under unsteady condition. As the nonuniform degree of inlet strip thickness and the roll radius increases， the absolute fluctuation of film thickness rises. However， the fluctuation frequency shows little effects on the absolute fluctuation of film thickness. References | Related Articles | Metrics

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Solution for Nonpermutation Flow Shop Scheduling with Buffers and Machine Availability Constraints ZHENG Yongqian， LI Yan 2014, 35 (9):  1329-1334.  DOI: 10.12068/j.issn.1005-3026.2014.09.026 Abstract ( 776 )   HTML   PDF (560KB) ( 666 )   To get a better nonpermutation flow shop(NPFS) scheduling， buffers， machine availability constraints and sequencedependent setup time were considered in building the mathematical model and disjunctive graph model. A NPFSoriented list heuristic algorithm was constructed to minimize the makespan. Allowed list and candidate list were built to record heuristic process information. Quantum ant colony and SPT heuristic rule were applied to search and select the feasible movement of related disjunction arcs to get an acyclic conjunctive graph. The algorithm parameters were verified through orthogonal test. The optimal disjunctive scheduling solution was the same with the exact CPLEX solution. The proposed algorithm has been critically compared and assessed by eight benchmark problems from Demirkol with the MHDACS and ACO ones， which confirms its good effectiveness and robustness. References | Related Articles | Metrics

Resources & Civil Engineering

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Synthesis of Micro/Nano Nesquehonite Whiskers with Magnesite Method WANG Yulian， YIN Wanzhong， YAO Jin， HOU Ying 2014, 35 (9):  1335-1339.  DOI: 10.12068/j.issn.1005-3026.2014.09.027 Abstract ( 727 )   HTML   PDF (628KB) ( 638 )   Micro/nano nesquehonite whiskers were synthesized with magnesite method. The effects of raw materials from different regions， pyrolysis temperatures and types of additive on phase compositions and morphology of products were respectively investigated by means of XRD and SEM. The results showed that well crystallized rodlike nesquehonite whiskers with high aspect ratio can be synthesized at the optimal pyrolysis temperature of 50 ℃， using magnesite from Kuandian and Xiuyan as raw materials. Nesquehonite whiskers become unstable when the pyrolysis temperature is over 50 ℃. The results of SEM analysis showed that pyrolysis products obtained are irregular rodlike and acicular mixed crystal without any additive. Smooth rodlike crystals with high aspect ratio were obtained with additive of absolute alcohol and sodium dodecyl sulfate. Stubby aggregates were obtained with additive of sodium polyphosphate. The essence of magnesite method was that Mg(HCO3)2 precursor solution was prepared by calcination， hydration and carbonation treatment using magnesite as raw material， then nesquehonite crystals could be synthesized through the pyrolysis of Mg(HCO3)2 solution. References | Related Articles | Metrics

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Effect of CoalRock Interface on Hydraulic Fracturing Propagation SONG Chenpeng， LU Yiyu， JIA Yunzhong， XIA Binwei 2014, 35 (9):  1340-1344.  DOI: 10.12068/j.issn.1005-3026.2014.09.028 Abstract ( 775 )   HTML   PDF (636KB) ( 1014 )   During hydraulic fracturing in coal seams， fractures expand to coalrock interface and the direction of fracture growth may change because of the effects of many mechanical factors. Based on the 2D model of coalrock interface in hydraulic fracturing， the theoretical analysis and numerical simulation were conducted to investigate the failure mechanism of coalrock interface and the propagation characteristics of fractures induced by hydraulic fracturing. It is shown that:the main factors which affect the development direction of fractures are intersecting angle between coalrock interface and horizontal profile， horizontal stress difference， minimum horizontal insitu stress， cohesive strength of coalrock interface and elastic modulus difference between coal and rock. With the decrease of intersecting angle or horizontal stress difference， the probability of fractures crossing coalrock interface will raise; while the minimum horizontal insitu stress increases， the probability of fractures crossing coalrock interface will reduce; with the decrease of cohesive strength of coalrock interface or increase of elastic modulus difference between coal and rock， the fractures will tend to extend along the coalrock interface. References | Related Articles | Metrics

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Effects of Volatile Component in Coal on HighPhosphorus Oolitic Hematite in Direct Reduction Roasting Process CAO Yunye， SUN Tichang， GAO Enxia， XU Chengyan 2014, 35 (9):  1346-1349.  DOI: 10.12068/j.issn.1005-3026.2014.09.029 Abstract ( 763 )   HTML   PDF (747KB) ( 601 )   Under the same reduction roasting condition and quantity of additive， a systematic research on the effect of volatile component in coalradicle reductant on high phosphorusoolitic hematite of Western Hubei in direct reduction roasting process was done， specifically on minerals containing iron and phosphorus. This study tries to elaborate preliminarily on the mechanism of volatile component in coalradicle by XRD and SEM. The results show that volatile component in coal is conducive to the increase of iron recovery while adverse to the decrease of phosphorus. Gangue minerals newly generated in roasted product are different when using two types of raw coals processed by dry distillation at high temperature as reductants. Moreover， complex reactions occur between ironcontaining minerals and chamosite or quartz in raw ore. As a result， most phosphoruscontaining minerals in raw ore still exist in the form of fluorapatite， but some will still take part in reduction roasting reaction. References | Related Articles | Metrics

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Dynamic Increase Factor During the Progressive Collapse of RC Frame Structures XIAO Shiyun， DONG Huahang， LIU Jinfeng 2014, 35 (9):  1350-1354.  DOI: 10.12068/j.issn.1005-3026.2014.09.030 Abstract ( 792 )   HTML   PDF (639KB) ( 801 )   The specification of dynamic increase factor(DIF)during the progressive collapse design of RC frame structures was studied， and the influence of maximum plastic angle， height， width， reinforcement ratio and the lengths of bay were studied systematically. The results demonstrate that the DIF of different models has the same trend and the maximum is about 113， which is far less than that given by the GSA Standard. The DIF decreases with the increasing plastic angle but increases with the increasing reinforcement ratio. The dynamic effect of RC structures after removing the corner column is greater than that after removing the interior column. Other factors， such as the aspect ratio， the lengths of bay， the section sizes and the loading pattern， have no significant influence on the DIF. References | Related Articles | Metrics

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Integrative Risk Analysis and Application of HAZOPLOPA Based on Bayesian Networks Inference〓 YAO Xiwen， XU Kaili， TANG Guicheng， WANG Wenjing 2014, 35 (9):  1356-1359.  DOI: 10.12068/j.issn.1005-3026.2014.09.031 Abstract ( 802 )   HTML   PDF (588KB) ( 692 )   Considering that the event tree and fault tree analysis bear some disadvantages， a new integrative risk analysis of HAZOPLOPA was proposed on the basis of Bayesian networks. The system fault tree was established and mapped into Bayesian networks by using GeNIe software. Then fault prediction and diagnosis could be conducted by Bayesian networks twoside reason function， and it could rapidly identify the system weakness， which was chosen to be the Bayesian risk fault node. Integrative risk analysis was used by combining HAZOP with LOPA， putting forward the corresponding independent protective layer， and the residual risk level could be determined according to failure probability of protective layer and semiquantitative risk matrix. This risk assessment model was then applied in the reactor regenerator system of RFCC equipment in Liaohe Petrochemical Industries Company， and the application results can verify the pertinence， objectivity and accuracy under the condition of uncertain information in complex system. References | Related Articles | Metrics

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Pricing Mechanisms and Coordination Strategies of ClosedLoop Supply Chain with DualChannel Recycling systems YU Chunhai， LI Xiang 2014, 35 (9):  1360-1363.  DOI: 10.12068/j.issn.1005-3026.2014.09.032 Abstract ( 694 )   HTML   PDF (456KB) ( 625 )   A recycling and remanufacturing system consisting of the remanufacturer， retailer and thirdparty recycler was investigated. In this dualchannel recycling model， product recycling of the closedloop supply chain was determined by the remanufacturer and thirdparty recycler. In addition， pricing mechanisms and coordination strategies were analyzed under decentralized and centralized decision with the method of game theory. Based on the Rubinstein bargaining model and discount factor theory， coordination strategy and Pareto improvement were established. Finally， a numerical example was given to illustrate the effectiveness of the pricing mechanisms and coordination strategies. This study proves that the dualchannel recycling model can not only improve all parties’ benefits but also promote the overall efficiency of this recycling and remanufacturing system. References | Related Articles | Metrics

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Research and Development Teams’ Incentive Mechanism Based on Value Creation SUN Shimin， DONG Yuheng， WANG Yanmei， GUAN Zhimin 2014, 35 (9):  1364-1367.  DOI: 10.12068/j.issn.1005-3026.2014.09.033 Abstract ( 1014 )   HTML   PDF (422KB) ( 718 )   In order to improve the research and development teams’ incentive mechanism， value creation was taken as performance standard and research and development teams’ incentive mechanism was studied on the premise of maximization for overall efficiency including individual task output， team task output and management task output. On the basis of the traditional conclusions， it is found that agents in monopoly industries make less effort than ones in competitive industries， so it is necessary to introduce competitive mechanism inside or transform monopoly industries into competitive industries when condition is mature. In the meantime， it is found that team cooperation and member’s support each other have significant positive influence on effort， which requires research and development teams to reinforce cooperation， encourage members to support each other and restrain defeating behavior. References | Related Articles | Metrics