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15 March 2018, Volume 39 Issue 3 Previous Issue    Next Issue
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Information & Control

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Steady-State Many-Objectives Evolutionary Algorithm Based on Objective Space Partition LI Fei， LIU Jian-chang， ZHU Jia-ni， LI Chen-xi 2018, 39 (3):  305-310.  DOI: 10.12068/j.issn.1005-3026.2018.03.001 Abstract ( 741 )   HTML   PDF (577KB) ( 1257 )   Due to the sharp increasing of the proportion of Pareto non-dominated candidate solutions for many-objective optimization problems， the commonly used many-objective evolutionary algorithms encounter the selection pressure deterioration problem considering the convergence-first-and-diversity-second selection approach. This paper proposed a many-objective evolutionary algorithm with the diversity-first-and-convergence-second selection strategy-steady-state many-objective evolutionary algorithm based on objective space partition (SS-OSP). Firstly， it divided objective space into a large number of subspaces using a set of weight vectors. Then， one individual in each subspace was selected via adopting aggregation function. In addition， since the penalty parameter of PBI aggregation function remained constant in evolutionary process， an adaptive PBI aggregation function was proposed. Finally， the experimental results show that better convergence and diversity can be obtained using the proposed algorithm. References | Related Articles | Metrics

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Network Traffic Short-Term Prediction Based on Echo State Network Optimized by Improved Black Hole Algorithm HAN Ying， JING Yuan-wei， JIN Jian-yu， LI Kun 2018, 39 (3):  311-315.  DOI: 10.12068/j.issn.1005-3026.2018.03.002 Abstract ( 809 )   HTML   PDF (539KB) ( 1032 )   The network traffic data series has chaos characteristics. After phase space reconstruction， a nonlinear prediction model based on echo state network (ESN) optimized by improved black hole (BH) was used to predict network traffic. The improved BH algorithm is a new mechanism for new-solution generation based on current works， which can increase the algorithms convergence speed and precision. Compared with other optimization algorithms， such as genetic algorithm (GA)， harmony search (HS) algorithm， etc， the proposed improved BH algorithm is not affected by the accuracy of the setting for some parameters of itself. It is used to optimally select four key parameters of the ESN model， which has better prediction stability. Simulation experiments of Mackey-Glass chaos time series and public network traffic data set show that the proposed method has better prediction ability. References | Related Articles | Metrics

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Reconstruction Algorithm of Compressed Sensing for Stepped-Frequency Continuous Wave Ground Penetrating Radar Based on Block Objects SHE Li-huang， WANG Pei-ren， ZHANG Shi 2018, 39 (3):  316-320.  DOI: 10.12068/j.issn.1005-3026.2018.03.003 Abstract ( 695 )   HTML   PDF (1145KB) ( 1215 )   Compressed sensing (CS) is of great significance to solving such problems as high sampling rate， huge storage pressure and long processing time in the process of stepped-frequency continuous wave ground penetrating radar (SFCW-GPR). Aiming at the problem that block objects can’t meet the sparseness in the detecting area， and using the orthogonal basis for sparse processing of block objects to satisfy the sparsity condition， a new observation matrix that was suitable for block objects was formed by combining the dictionary matrix and sparse matrix. The sparse coefficients were solved by using the compressed sensing convex optimization algorithm. Finally， the reflection coefficients of block objects were obtained through sparse transformation of the sparse coefficients. The simulation results showed that the proposed method is feasible and has higher accuracy and resolution ratio compared with the compressed sensing reconstruction model without sparsity. References | Related Articles | Metrics

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A Cross Layer Resource Allocation Algorithm for Constellation Communication System Based on QoS YU Xiao， LEI Wei-min， XIE Bing， ZHAO Jin-feng 2018, 39 (3):  320-324.  DOI: 10.12068/j.issn.1005-3026.2018.03.004 Abstract ( 681 )   HTML   PDF (1086KB) ( 1096 )   In view of the problem that the satellite-ground link resource allocation is not flexible， and the effective QoS(quality of service) guarantee mechanism is lacking， a cross layer resource allocation algorithm for constellation communication system is proposed on the basis of QoS. By using adaptive encoding modulation (ACM) technology， and defining user channel quality assessment algorithm， adjustable fairness scheduling algorithm， QoS business classification scheduling algorithm and user service allocation weight function， the terminal user can be specified physical layer parameters such as working frequency， time slot， coding mode， modulation mode， and etc. The allocation of physical layer channel resources could be realized flexibly according to the QoS security requirements， and the balance could be reached between enhancing the system utilization rate and meeting the QoS security requirements. The simulation results show that the proposed algorithm can achieve the reasonable scheduling of satellite-ground link resources based on the business QoS and user channel quality. References | Related Articles | Metrics

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Prediction of Disease-Related miRNAs via Functional Network Information Propagation LI Jian-hua， LUO Shi-yuan， ZHANG Jian-ying， KANG Yan 2018, 39 (3):  325-329.  DOI: 10.12068/j.issn.1005-3026.2018.03.005 Abstract ( 830 )   HTML   PDF (386KB) ( 862 )   In order to quickly find out disease-related miRNAs， PMBP algorithm was proposed for improving random walk based on functional network information propagation. Leave-one-out cross validation was utilized to evaluate the performance of the algorithm and finally a case was analyzed. The results showed that random walk is ineffective for diseases that have not yet been associated with miRNAs， but the miRNA can be effectively predicted by using disease similarities as prior information. For the diseases known to be related with miRNAs， PMPB achieves a better performance and the corresponding AUC value is 0.866. In the case study of breast cancer， the predicted top 50 miRNAs are confirmed to be associated with breast cancer， which indicates the validity of PMBP. References | Related Articles | Metrics

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Modeling Simulation of Upper Limb Vascular System Based on Fusion of Windkessel and Tube-Load Models ZHOU Shu-ran， YAO Yang， HAO Li-ling， XU Li-sheng 2018, 39 (3):  329-333.  DOI: 10.12068/j.issn.1005-3026.2018.03.006 Abstract ( 843 )   HTML   PDF (509KB) ( 974 )   In response to the problem that the tube-load model is suitable to simulate large and medium-sized arteries， not suitable to simulate small arteries and arterioles， the model combining windkessel model with tube-load model was established to improve the simulation accuracy for the human upper limb vascular system. Firstly， the tube-load model was applied to the simulation from brachial artery to radial artery， and the windkessel model was established in the section from radial artery to finger artery， respectively. Secondly， based on the continuity principle of blood pressure and blood flow in the interface of two models， the relationship of the two models was built and a fusion model was derived by combining the two models. Finally， the simulation performances of the tube-load model and the fusion model were compared. With the evaluation indexes， such as PRD， H1， H2， t1 and t2， the error between the measured waveform and the simulated waveform of the fusion model ( PRD: (4.0±2.0) %; t1: (2.5±1.7) %; t2: (3.1±1.9) %; H1: (1.9±2.1) %; H2: (1.3±1.3)% ) is lower than that of the tube-load model (PRD: (16.5±8.3)%; t1: (3.4±2.4) %; t2: (4.5±3.7) %; H1: (22.1±14.9) %; H2: (19.7±15.3) % ). The results show that the fusion model can accurately simulate the physiological state in the human upper limb vascular system. References | Related Articles | Metrics

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Modified Flower Pollination Algorithm and Applications on Optimization Dispatch of Microgrid WANG Sheng-sheng， DU Peng， DONG Ru-yi， LI Yong-he 2018, 39 (3):  334-338.  DOI: 10.12068/j.issn.1005-3026.2018.03.007 Abstract ( 783 )   HTML   PDF (465KB) ( 778 )   The swarm intelligence algorithm for solving the problem of optimization dispatch of microgrid was investigated. A model for optimization dispatch of microgrid was established under the consideration of the process characteristics， such as multi-objective and multi-constraints. A modified flower pollination algorithm (MFPA) was proposed and applied to the optimization dispatch of microgrid. During initialization， opposition method was utilized to improve the diversity of the population as well as fully explore the space. During local updating， the new operation can accelerate the convergence. In addition， the condition for using genetic operations was defined in order to reduce the calculation and avoid the local optimal solution. Simulation results demonstrated that the performance of MFPA was better than those of FPA， GA and several other algorithms. References | Related Articles | Metrics

Materials & Metallurgy

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Microstructure and Properties of Ti Microalloyed Automobile Frame Steel 510L CHEN Qi-yuan， ZHOU Xiao-guang， LIU Zhen-yu， WU Si-wei 2018, 39 (3):  339-344.  DOI: 10.12068/j.issn.1005-3026.2018.03.008 Abstract ( 708 )   HTML   PDF (4435KB) ( 1148 )   The effects of cooling process parameters on microstructure and mechanical properties of Ti microalloyed automobile frame steel 510L were studied by laminar cooling， coiling process simulation experiment and laboratory hot rolling experiment. Industrial trial production was made at the production site. The results showed that great cooling rate is advantageous to the precipitation of dispersed and fine TiC particles. The effects of cooling rate and final cooling temperature on the strength of the experimental steel include the joint action of precipitation strengthening， fine grain strengthening and phase transformation strengthening. N content significantly influences the precipitation strengthening effect of Ti. The N content in the steel should be strictly controlled during smelting， otherwise it will have a great influence on the properties of the steel plate. Mass stable production of Ti microalloyed automobile frame steel 510L with low cost has been realized. References | Related Articles | Metrics

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Effect of Flatness Actuators in UCM Mill on Rolling Pressure Distribution WANG Qing-long， SUN Jie， WANG Zhen-hua， ZHANG Dian-hua 2018, 39 (3):  345-350.  DOI: 10.12068/j.issn.1005-3026.2018.03.009 Abstract ( 930 )   HTML   PDF (1445KB) ( 874 )   Based on a 1420mm tandem cold rolling mill in a domestic plant， rolling processes in an UCM mill were simulated by 3D elastic-plastic finite element method(FEM). Effects of work roll bending(WRB)， intermediate roll bending(IRB)and intermediate roll shifting(IRS)on the rolling pressure were investigated. The results showed that peak values of rolling pressure near the strip edge disappear and the central rolling pressure increases with increasing of WRB， and the saddle-shaped distribution of rolling pressure becomes a convex-shaped distribution. Rolling pressure is hardly affected by IRB， and its distribution form is not changed basically. The sharply increased trend of rolling pressure near the strip edge is eliminated due to IRS， and the steep pressure field becomes smooth. Rankings of effects of the three actuators on rolling pressure are: WRB>IRS>IRB， which is in good agreement with the comparison of actuator efficiencies， and it shows that the working mechanism of controlling strip shape is achieved by affecting the rolling pressure distribution. References | Related Articles | Metrics

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Dissociation Behavior of Al-Fe in the “Calcification-Carbonization” Process for High-Iron Bauxite ZHANG Wei-guang， ZHANG Ting-an， LYU Guo-zhi， GUO Fang-fang 2018, 39 (3):  351-356.  DOI: 10.12068/j.issn.1005-3026.2018.03.010 Abstract ( 877 )   HTML   PDF (848KB) ( 810 )   Aiming at dissociation problem of Al-Fe in hydrometallurgical extraction process for high-iron diaspore bauxite， “calcification-carbonization-reducing iron” method was proposed for effectively extracting valuable metal Al and Fe. Andradite-grossular hydrogarnet was synthetized by pure material， and the transformation behavior in novel technology was investigated for effective dissociation and comprehensive recovery of Al-Fe from high-iron bauxite. The results showed that the andradite-grossular hydrogarnet is synthetized in the range of 483~533K in Na2O-Al2O3-CaO-SiO2-Fe2O3-H2O system， in which chemical property is relatively stable. In the carbonization process， andradite-grossular hydrogarnet is decomposed entirely， producing CaCO3， Ca2SiO4， Fe2O3 and a little grossular hydrogarnet. Moreover， 52.7% of Al2O3 is extracted in dissolving alumina process and 77.2% of Fe is reduced in the directly reducing iron process. References | Related Articles | Metrics

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Numerical Simulation of Liquid Phase Flow in a Self-Stirring Reactor GUO Xu-huan， ZHANG Zi-mu， ZHAO Qiu-yue， ZHANG Ting-an 2018, 39 (3):  357-362.  DOI: 10.12068/j.issn.1005-3026.2018.03.011 Abstract ( 714 )   HTML   PDF (3412KB) ( 769 )   The distribution of liquid phase flow field in a self-stirring reactor driven by pressure energy was studied by numerical simulation method. Firstly， the appropriate turbulence model was determined by comparing the simulation results of the standard k-ε model， RNG k-ε model， and realizable k-ε model with the PIV experimental results.Then the influence of inlet pressure and liquid level height on the fluid field distribution in the reactor was studied. The results showed that the standard k-ε turbulence model can accurately simulate fluid field distribution of the reactor， and the stable time is more than 12 s. Increasing inlet pressure and liquid height is favorable to the even distribution of fluid velocity in the reactor， and there is almost no dead zone of velocity when inlet pressure is 3MPa. References | Related Articles | Metrics

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Consumption Mechanism of Sodium Sulfide in Flotation Separation of Copper and Molybdenum WANG Jian， LIU Zi-long， CHEN Guo-bao， YANG Hong-ying 2018, 39 (3):  362-366.  DOI: 10.12068/j.issn.1005-3026.2018.03.012 Abstract ( 902 )   HTML   PDF (524KB) ( 964 )   In the production process of copper-molybdenum flotation separation， the consumption of sodium sulfide inhibitors is always high. The high consumption of sodium sulfide dramatically increases the production cost of copper-molybdenum flotation separation. The mechanism of large consumption for sodium sulfide was preliminary studied in copper-molybdenum flotation separation. Under the different experiment conditions， dynamic monitoring approach was used to quickly measure the change of sulfide ion concentration in sodium sulfide solution by sulfide ionic selective electrode. The results showed that the oxidation of sodium sulfide can be catalyzed by flotation mineral(molybdenite， chalcopyrite and pyrite)and metal cation(Cu2+ and Fe3+)from flotation pulp. Moreover， the blowing air to flotation pulp and lower pulp temperature can also accelerate the oxidation consumption of sodium sulfide in flotation process.As a result， the large consumption of sodium sulfide is caused by catalysis action from mineral and metal cation， adsorptive action of mineral， the effect of flotation pulp temperature and blowing air to flotation pulp. References | Related Articles | Metrics

Mechanical Engineering

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Research on Fault Diagnosis Information of Open Crack for Rotor System LIU Yang， SHI Tuo， YAO Hong-liang， WEN Bang-chun 2018, 39 (3):  367-372.  DOI: 10.12068/j.issn.1005-3026.2018.03.013 Abstract ( 621 )   HTML   PDF (616KB) ( 705 )   According to the rotor system with crack fault caused by transverse open crack， the dynamic model of crack rotor system was established using the crack compliance coefficient matrix that is derived from the stress intensity factors and strain energy density function based on the Paris theory. Since the stiffness matrix of rotor system with transverse crack fault will have corresponding changes， the surplus dynamics equation of cracked rotor system can be deduced by comparing the dynamics equations of the fault-free rotor system with that of the crack rotor system based on the flexibility coefficient matrix. Moreover， the information of open crack’s location and depth can be extracted from the vibration signal by analyzing stress condition at both ends of the shaft segment where crack exists and combining with the surplus dynamics equation. The results show that the open crack information extraction method used in this paper only needs to collect the vibration signal of three nodes at two different speeds to make diagnostic analysis. This method is simple and feasible， which may provide certain theoretical basis for the open crack fault diagnosis of the rotor system， cantilever beam and truss structure. References | Related Articles | Metrics

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Finite Element Modeling of Punching Drive Axle Housing Parameterization Based on Isight LIU Bo-lin， XIE Li-yang， ZHANG Na， LUO Yi-jian 2018, 39 (3):  373-377.  DOI: 10.12068/j.issn.1005-3026.2018.03.014 Abstract ( 817 )   HTML   PDF (1812KB) ( 1060 )   In order to solve the inefficient problem about the finite element modeling of drive axle housing， by combining the parametric modeling function of Pro_E with the finite element analysis function of ABAQUS and considering the influence of punching process and welding process， the parametric finite element analysis process and the model of drive axle housing were built based on the multidisciplinary design optimization software Isight. This method effectively solves the problems of model description， parameter driving and automatic updating in the process of parametric finite element analysis of complex structures. It not only provides a new solution to similar problems， but also provides an effective tool for the reliability prediction and evaluation of drive axle housing. The results demonstrated that the proposed method is reasonable and feasible. References | Related Articles | Metrics

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Six-Axis Manipulator’s Sliding Mode Robust Control Based on T-S Fuzzy Compensation WANG Hong， ZHENG Tian-qi， JI Li， LU Zhi-guo 2018, 39 (3):  378-383.  DOI: 10.12068/j.issn.1005-3026.2018.03.015 Abstract ( 677 )   HTML   PDF (818KB) ( 764 )   A simple fuzzy sliding mode control was proposed to obtain the optimum movement of a manipulator’s trajectory tracking. The core of the proposed method is to use the feedback linearization method to remove the known kinetics of the manipulator， use the classical sliding mode control to overcome the system uncertainty， and then apply the T-S fuzzy model to translate the classical sliding mode controller into a fuzzy sliding mode controller with very simple fuzzy rules. The simulation results showed that in the case of uncertainty， the proposed control law is globally asymptotically stable. Finally， the co-simulation of the six-axis manipulator by Matlab / Adams verified the accuracy of the model. By comparing the classical sliding mode control result， the proposed method under the conditions of structured and unstructured uncertainties has a high performance. References | Related Articles | Metrics

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Chain Formation and Agglomeration Characterization of Magnetic Particles in Magnetorheological Fluids MA Liang， XIAO Ping， WANG Ren-sheng， XIU Shi-chao 2018, 39 (3):  383-388.  DOI: 10.12068/j.issn.1005-3026.2018.03.016 Abstract ( 690 )   HTML   PDF (600KB) ( 934 )   Thermal motion behavior has an unneglectable disturbing effect on the agglomeration and rheological characteristics of nano-size magnetorheological fluids(MRFs).To discover the relationship between microstructure and thermal motion in MRFs with external magnetic fields applied， the thermal proportion of total energy with different diameters of carbonyl iron particles (CIPs) was discussed. The CCD method was employed to analyze the CIPs’ position data set calculated by Monte Carlo simulation， and a systematic thermal coupling coefficient<λ>regression model related to magnetic induction intensity， CIPs’ diameter and volume concentration was built. The threshold particle diameter value calculated by the model is 23% higher than the empirical value in the literature， which proves that rheological characteristic has a stricter precondition with multiple factors considered in MRFs. References | Related Articles | Metrics

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Scheduling Method of Material Delivery for Automotive Assembly Lines Based on Milk-Run Delivery ZHOU Bing-hai， TAN Fen 2018, 39 (3):  389-393.  DOI: 10.12068/j.issn.1005-3026.2018.03.017 Abstract ( 729 )   HTML   PDF (426KB) ( 861 )   To efficiently solve the scheduling problem of material delivery for automotive assembly lines based on milk-run delivery， a scheduling method was developed by the modified immune clone selection algorithm. Firstly， a mathematical programming model was set up with an objective function of minimizing total inventory for all stations over the planning horizon. Then， a modified immune clone selection algorithm was developed to solve the proposed problem. Both the simulated annealing operator and neighborhood search operator were applied to clone population and memory vault， respectively， in the design of algorithm. It overcomes deficiencies of the traditional immune clone selection algorithm， such as tendencies to trap into local optima and limited search depth. Finally， the simulation experiments were carried out and the results indicate that the as-proposed algorithm is valid and feasible. References | Related Articles | Metrics

Resources & Civil Engineering

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Palaeoenvironment Significance of Dakangpu Layer Varve in Yixian Formation in Lower Cretaceous of Western Liaoning WANG Tie-hui， GONG En-pu， CHEN Xiao-hong， HUANG Wen-tao 2018, 39 (3):  394-398.  DOI: 10.12068/j.issn.1005-3026.2018.03.018 Abstract ( 775 )   HTML   PDF (2247KB) ( 1180 )   Lake sediments of Yixian formation in the western part of Liaoning Province output the famouse “Jehol Biota” fossils， it is a hot issue for the study of the palaeoenvironment at this period. This paper focuses on the varves in Dakangpu Layer and reconstruct the lacustrine palaeoenvironment. New understanding of the palaeoclimate in this period is obtained through carefully observing the composition， type， thickness of varve in the field and laboratory. The change of varve thickness indicates the decrease in the precipitation and deposition rates in Dakangpu stage. The thickness of the varve between the flood deposits can be used to interpret the frequency and scale of the flood events. Combined with the deposition and preserved environmental conditions of modern varves， during the deposition period of Dakangpu Layer， there is a specific depositional environment and a deep， stratified， oxygen-restricted， low surface area/depth ratio lake. References | Related Articles | Metrics

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Thermal Decomposition Process and Kinetics of Micro-fine Magnesite BAI Li-mei， DENG Yu-fen， HAN Yue-xin， ZHAO Wen-qing 2018, 39 (3):  398-403.  DOI: 10.12068/j.issn.1005-3026.2018.03.019 Abstract ( 857 )   HTML   PDF (1658KB) ( 1197 )   Thermal decomposition kinetics of highly pure micro-fine magnesite particles was studied by TG-DSC techniques at varying heating rates. The results indicate that with increase of heating rate， decomposition rate of magnesite increases gradually and maximum decomposition rate shifts to the high-temperature zone. Firstly， TG experimental data obtained at different heating rates were calculated with Hu-Gao-Zhang equation， which determined uniqueness and activation energy value of thermal decomposition mechanism function of magnesite. And then double equal-double steps method combined with morphological analysis on calcined products were adopt to determine differential form for most probable mechanism function of thermal decomposition， it is f(α)=2(1-α)1/2， and the outside-in (i.e. from cleavage surfaces to the interior of crystal) thermal decomposition of particles is a typical phase boundary reaction. Finally the pre-exponential factor was calculated by Flynn-Wall-Ozawa equation， and thermal decomposition kinetics equation of micro-fine magnesite is established. Two sets of TG data with different heating rates were used to verify the established equation and prove it is reasonable equation. References | Related Articles | Metrics

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Surface Property of Serpentine LI Zhi-hang， HAN Yue-xin， LI Yan-jun， GAO Peng 2018, 39 (3):  404-408.  DOI: 10.12068/j.issn.1005-3026.2018.03.020 Abstract ( 860 )   HTML   PDF (760KB) ( 1163 )   Dissolution experiments， SEM， Zeta potential tests and XPS are used to analyse the surface property of serpentine. The results showed that the surface of serpentine is prone to dissolve in aqueous solution and make pulp pH alkaline， which reveals strong buffer ability. Compared with undissolved serpentine， embossment and flocculent structure are observed on the surface topography of dissolved serpentine. Besides， the surface elements content also has a big diffrence. The crystal structure of serpentine was discussed to understand the dissolution mechanism. The result indicated that large amounts of Mg2+ and —OH expose on serpentine surface after grinding and transfer to aqueous solution which leading to a high pH value and high content of Mg2+ of pulp. Furthermore， because of more —OH exposed on fine-grained serpentine surface， the rise of pH value is more remarkable and higher pH value is obtained. References | Related Articles | Metrics

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Effects and Activation Mechanism of Calcium Ion on the Flotation of Quartz with Fatty Acid Collector GUO Wen-da， ZHU Yi-min， HAN Yue-xin， WEI Yi-he 2018, 39 (3):  409-415.  DOI: 10.12068/j.issn.1005-3026.2018.03.021 Abstract ( 845 )   HTML   PDF (1049KB) ( 1078 )   To investigate the effects and activation mechanism of calcium ion on quartz in the flotation process with fatty acid collector， flotation tests， Zeta potential measurements and infrared spectroscopy analysis were applied. The results showed that flotation of quartz requires the activation of calcium ions， and calcium ions can increase the surface zeta potential of the quartz and the modified fatty acid collector DWD-3 can be adsorbed on the surface of the activated quartz through chemical and hydrogen bonding adsorption. The results of quantum mechanics simulation indicated that Ca2+， Ca(OH)+ and OH-ions can all adsorbe on the quartz surface， and Ca2+ ion adsorption is the strongest. The process of Ca2+ion activation is that Ca2+ preferentially adsorbs on the O position of the quartz surface by chemical adsorption， forming a surface activated by Ca2+， then a single-bond oxygen (OⅠ) and two double-bond oxygen (OⅡ) of the collector DWD-3 adsorbe on the activated quartz surface by chemical and hydrogen bond adsorption. References | Related Articles | Metrics

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Prediction of Surface Subsidence Range Based on the Critical Medium Column′s Theory Under Ore Drawing LIU Yang， REN Feng-yu， HE Rong-xing， CAO Jian-li 2018, 39 (3):  416-420.  DOI: 10.12068/j.issn.1005-3026.2018.03.022 Abstract ( 725 )   HTML   PDF (919KB) ( 953 )   The critical medium column′s theory is used to determine critical medium column′s height using lateral pressure and predict surface subsidence range. Past lateral pressure tests usually lead to inaccurate forecasts without considering the influence of ore drawing on lateral pressure. So an experimental test on lateral pressure of bulk-solid medium was performed to measure the lateral pressure under ore drawing， and the effects of releasing bulk-solid medium on lateral pressure were got through the comparisons among the different heights. The result shows that the lateral pressure is effected at the vicinity of drawing hole under ore drawing， and the effects′ range is little by releasing bulk-solid and lateral pressure increases with the consolidation of bulk-solid medium. Combined the critical medium column′s theory and the classical Janssen theory， the calculation of the critical medium column′s height under the effect of ore drawing was obtained. Then considered the relationship between mining height and the disturbed angle， reference for prediction of surface subsidence range was provided. References | Related Articles | Metrics

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Precise Control of Concrete Temperature History for Concrete Buried Heat Source in Winter LIU Lin， ZHAO Wen 2018, 39 (3):  421-425.  DOI: 10.12068/j.issn.1005-3026.2018.03.023 Abstract ( 724 )   HTML   PDF (453KB) ( 733 )   Aiming at the control temperature method of concrete buried heat source in winer， the influence of heat source on the temperature change of concrete was studied. Based on maturity concept， the effects of temperature and age on the degree of hydration and the development of thermal properties were considered. According to the prediction formula of compressive strength， the temperature history was designed in advance. Based on the first law of thermodynamics， the instantaneous heat equation was established. The precise temperature control method was established and verified by experiments. The results showed that this method can accurately control the temperature rise of concrete， maintain stable temperature， ensure the cooling rate of concrete， and achieve precise control of temperature history and strength of concrete. References | Related Articles | Metrics

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Mechanical Response of Anchored Pile Supporting Deep Excavation Influenced by Local Anchor Failure HAN Jian-yong， ZHAO Wen， JIA Peng-jiao， CHEN Yang 2018, 39 (3):  426-430.  DOI: 10.12068/j.issn.1005-3026.2018.03.024 Abstract ( 721 )   HTML   PDF (893KB) ( 733 )   Under the engineering background of anchored pile supporting excavation in sand layers， numerical models were established using the FEM program Plaxis to simulate excavations under two local anchor failure conditions of one-row and two-row anchor cable failures. The effect of prestressed anchor failures on mechanical response of retaining structures was studied. Besides， the load transfer response to the anchor failures was revealed. The results obtained from the numerical simulations show that the influence of two-row anchor cable failure on deformation and internal force of retaining structure was larger than that of one-row anchor cable failure. Under the most unfavorable condition of group anchor failures， the bending moments and displacements of retaining piles were 1.66 and 1.74 times of those under the normal construction condition， respectively， and the increase ratio of the bending moment of the retaining piles was the crucial determining factor of the piles failure. References | Related Articles | Metrics

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3D Numerical Analysis for Effect of Mechanical Properties on Failure Process of Serial and Parallel Rock Pillar System JIA Peng， ZHANG Yao， JI Wan-min， ZHAO Ai-cheng 2018, 39 (3):  431-436.  DOI: 10.12068/j.issn.1005-3026.2018.03.025 Abstract ( 710 )   HTML   PDF (2038KB) ( 692 )   When mining in deep rock mass under high stress and complicated geological conditions， the stability of rock pillar system is quite important for safe-mining. A series of numerical simulations were conducted to evaluate the effect of uniaxial compressive strength on the failure processes of serial and parallel pillar systems by using the RFPA3D-Parallel code. Results show that the stability of the serial pillar system depends on pillar of lower uniaxial compressive strength， which means that monitoring and reinforcement of the relatively weak pillar in the serial pillar system is quite essential to the stability control of the serial pillar system. For the parallel pillar systems， the pressure-transfer is closely related to the compressive strength of the pillars， that is， stress will be transferred from the weak pillar to the strong pillar till the failure of the whole pillar system. It is also found that the multi-peak phenomenon of the acoustic emission(AE) counts or the step-curve of the accumulative AE counts can be deemed as the hint of stress transfer from the fractured weak pillar to the nearby strong pillars. References | Related Articles | Metrics

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Numerical Simulation on Characteristics of Crankle Air Filter Used in Locomotive LIN Xiu-li， CAO Ya-ping， DONG Si-jing， LIU Jing-xian 2018, 39 (3):  436-440.  DOI: 10.12068/j.issn.1005-3026.2018.03.026 Abstract ( 691 )   HTML   PDF (1026KB) ( 712 )   The influence of channel width， crankle angle and crankle number on the pressure drop of crankle air filter used in locomotive was studied. The characteristics of crankle air filter under higher flow velocity (≥5m/s) was analyzed emphatically. The results show that the pressure drop of filter with 16 mm channel width increases fast under higher air flow velocity. The pressure drop decreases 36% if the channel width increases 25% under 6.5m/s air flow velocity for 16mm and 20mm channel width filter. The change of crankle angle affects the pressure drops obviously under higher air flow velocity. The pressure drop decreases 40% when the crankle number decreases from 3 to 2， and the channel thickness decreases about 29%. Under conditions of high wind speed and low pressure drop， the geometrical parameters of the filter can be designed according to the research results， and the crankle filter can be used as the first stage of multi-stage filtration. References | Related Articles | Metrics

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Experiment and Mechanistic Study on Adsorption and Removal of Heavy Metals in Water by Corncob-Based Activated Carbon ZHAO Yan， LANG Lang， JIANG Bin-hui， DENG Shuo 2018, 39 (3):  441-445.  DOI: 10.12068/j.issn.1005-3026.2018.03.027 Abstract ( 1109 )   HTML   PDF (697KB) ( 957 )   The corncob-based activated carbon was prepared by the carbonization with muffle furnace under different process conditions， and the corncob of wasted crops was used as raw material. The adsorption performance for heavy metals， such as Zn， Mn and Pb， were investigated， and the adsorption mechanism of the corn cob-based activated carbon for heavy metal zinc was studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM and EDS). Then the desorption experiment was carried out on the adsorbent after adsorption. The results showed that the corncob-based activated carbon prepared by appropriate technology has a very high adsorption rate for zinc ions in water， the adsorption kinetic behavior accords with the quasi-second order kinetics equation. For the desorption of corncob-based activated carbon， the effect of acid desorption is better than electric field intervention desorption. The preliminary conclusion is that the corncob-based activated carbon can be used for absorbing heavy metals and is a kind of low-cost adsorbent. References | Related Articles | Metrics

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Experimental Study on Disintegration of Excess Sludge by Explosive Shock Wave XIE Yuan-hua， MEI Jian， WANG Jie， ZHU Tong 2018, 39 (3):  446-450.  DOI: 10.12068/j.issn.1005-3026.2018.03.028 Abstract ( 674 )   HTML   PDF (913KB) ( 661 )   To investigate the effect of explosive shock wave on disintegrating excess sludge， two types of explosives (RDX and TNT) were employed under different dosages (10g and 70g) and different sludge concentrations (MLSS(mixed liquid suspended solids)， 20~50 g·L-1) to carry out the experiments. Chemical oxygen demand (COD)， peptidoglycan， protein and particle size distribution(D50) of sludge before & after disintegration were selected as evaluation indexes. The results show that all concentration indexes present an increasing trend with explosive dosage increasing from 10g to 70g， and the effect of RDX is better than that of TNT. D50 after disintegration is not distinctively affected by explosive type， dropping from about 36μm to about 24μm for both RDX and TNT. Under explosive dosage of 70g， all concentration indexes show a rising trend with the increase of MLSS as well， but their corresponding increasing rates present mostly an upward trend followed by a downward trend. No matter for RDX or TNT， D50 after disintegration are both around 24μm. The variation of MLSS has no much effect on D50. References | Related Articles | Metrics

Management Science

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Mutual Guarantee: Joint Liability， Mutual Margin and Peer Effort CHENG Chun-yu， ZHONG Tian-li 2018, 39 (3):  451-456.  DOI: 10.12068/j.issn.1005-3026.2018.03.029 Abstract ( 805 )   HTML   PDF (491KB) ( 937 )   A basic model was designed for the current mutual guarantee mode， which analyzed the effect of joint liability and mutual margin on the effort level of member enterprises. In order to encourage the efforts of member enterprises， it was proposed to strengthen the supervision and punishment mechanism and the sequential lending mechanism， and the effectiveness of these mechanisms was verified by establishing a dynamic incentive model. The results showed that under the existing mutual guarantee mechanism， the greater the joint liability and margin are， the lower the effort of the member enterprises will be. The supervision and punishment mechanism and the sequential lending mechanism can prevent member enterprises from taking low effort actions. References | Related Articles | Metrics