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15 March 2019, Volume 40 Issue 3 Previous Issue    Next Issue
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Information & Control

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Billet Temperature Predication Model of Reheating Furnace Based on Data Features YANG Ying-hua， SHI Xiang， LI Hong-ru 2019, 40 (3):  305-309.  DOI: 10.12068/j.issn.1005-3026.2019.03.001 Abstract ( 805 )   HTML   PDF (426KB) ( 1065 )   Considering that the industrial process of reheating furnace is with the characteristics of complexity， non-linearity and time delay， and the prediction of billet temperature is difficult to achieve， an improved principal component regression(PCR)and prediction method based on data features is proposed in this paper. The time-delay among different variables is solved at first by synchronization of the original data. Then statistic and entropy features are extracted from each billet of reheating furnace and these data features consist of a data feature vector orderly. Lastly， the prediction model between billet outlet temperature and data features of process variable is established by PCR. The proposed method is applied in the reheating furnace of a real steel factory， and the model parameter is reckoned based on actual operational data. The experiment results and error analysis indicate that this model is able to predict the billet steel outlet temperature， and the prediction error can satisfy the demands of industrial application. References | Related Articles | Metrics

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Simulation of 3-SPS/S Parallel Manipulator Control System for Ankle Rehabilitation WANG Hai-fang， LI Xin-qing， QIAO Xiang-yang， QI Chao-fei 2019, 40 (3):  310-315.  DOI: 10.12068/j.issn.1005-3026.2019.03.002 Abstract ( 966 )   HTML   PDF (871KB) ( 826 )   The ankle is one of vulnerable parts of the low limb joints of the human body. Based on its structural characteristics， a 3-SPS/S parallel manipulator for ankle rehabilitation is built， and the inverse kinematics is solved by its dimensional characteristics. Then， the simulation platform of 3-SPS/S parallel manipulator for ankle rehabilitation is established by SimMechanics toolbox in Matlab software. A target trajectory is provided to produce input signals of actuating arms. Afterwards， the dynamics of parallel rehabilitation manipulator model are analyzed， and 3D rendering is generated. The experimental results show that it can provide the efficient and visual simulation platform to study the control strategy of parallel rehabilitation manipulator. References | Related Articles | Metrics

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Response Time Analysis of Multiprocessor Systems for DAG Parallel Tasks Based on G-EDF HAN Mei-ling， DENG Qing-xu， ZHANG Tian-yu， LIN Yu-han 2019, 40 (3):  315-320.  DOI: 10.12068/j.issn.1005-3026.2019.03.003 Abstract ( 750 )   HTML   PDF (483KB) ( 773 )   Since the self-structure of the DAG(directed acyclic graph)task is not considered， the schedulability analysis of the DAG parallel task model based on G-EDF(global earliest deadline first)is very pessimistic. The response time analysis of the DAG task set under the G-EDF scheduling strategy in multiprocessor systems was studied in this paper. First， a more accurate carry-in workload estimation method was proposed for the execution of the carry-in task instance. Then a method for estimating the problem window workload of completion time was put forward based on the carry-in workload estimation method. Based on the two proposed methods， this paper proposed a response time analyzing method to derive a response time upper bound of each task. The experiments show that the proposed method outperforms the state-of-the-art method by at least 15% and at most 25%. References | Related Articles | Metrics

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Multi-keyword Searchable Encryption Based on Paillier and Private Set Intersection ZHOU Fu-cai， ZHANG Zong-ye， WANG Kai-xuan， LI Yu-xi 2019, 40 (3):  321-326.  DOI: 10.12068/j.issn.1005-3026.2019.03.004 Abstract ( 788 )   HTML   PDF (484KB) ( 1062 )   Efficient multi-keyword ciphertext search and problems of data security protection were researched. Based on Paillier homomorphic encryption and private set intersection(PSI)technique， a multi-keyword searchable encryption scheme was provided， which can search over encrypted files efficiently and protect the search pattern. First， through random number padding and Paillier homomorphic encryption the index privacy and the trapdoor privacy were protected， and the search pattern was further protected. Then， the scheme supports conjunctive multi-keyword search by using PSI. Because only multiplications and exponentiations were used in searching， the proposed scheme is more efficient than others. Security and performance analysis showed that the scheme has the semantic security of searchable encryption and can perform multi-keyword search efficiently with a good computational cost. References | Related Articles | Metrics

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Integrity Assurance of Outsourced Spatial Database HONG Jun， WEN Tao， YE Zheng-wang， KANG Jun 2019, 40 (3):  327-333.  DOI: 10.12068/j.issn.1005-3026.2019.03.005 Abstract ( 601 )   HTML   PDF (741KB) ( 694 )   User′s data stored on a cloud computing service provider may be tampered or deleted. The query integrity verification scheme enables a query user to verify that the data in the query results is authentic and all the data that meet the criteria are in the query results. As an improvement of the existing authenticated tree schemes， a space authenticated data structure， called verifiable SS-tree(VSS-tree)， is proposed to support spatial query and query authentication. The VSS-tree extends each node of SS-tree with authentication information. Boundary sphere is used for region shape which increases the degree of node and thus reduces the height of authenticated tree. Furthermore， it can avoid unnecessary disk access， which improves the processing efficiency of spatial query verification. Experimental results showed that VSS-tree can efficiently support spatial query and has better performance than MR-tree. References | Related Articles | Metrics

Materials & Metallurgy

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Microstructural Evolution and Strengthening Mechanism of X65 Pipeline Steel Processed by Ultra-fast Cooling WANG Xue-qiang， ZHAO Jin-hua， YUAN Guo， WANG Guo-dong 2019, 40 (3):  334-339.  DOI: 10.12068/j.issn.1005-3026.2019.03.006 Abstract ( 731 )   HTML   PDF (1740KB) ( 892 )   Based on the hot-rolling production line， a novel processing of ultra-fast cooling(UFC)was developed to produce X65 pipeline strip. Microstructure of the experimental steel after the new processing was studied and the strengthening mechanism was further discussed. The results showed that microstructure of the UFC processed X65 pipeline strip primarily consists of fine acicular ferrite(AF)， quasi-polygonal ferrite(QPF)， martensite/austenite(M/A)and degenerate pearlite(DP). The effective grain size is 2.93μm and the proportion of the high-angle boundary in the microstructure is 31.5%. Small block ferrite with the size ranging from 200 to 1000nm is observed in the substructure. A large fraction of nano-sized Nb(C，N)particles(＜10 nm) are observed in the ferrite matrix. Moreover， mechanical properties of the experimental steel met to the API SPEC 5L standard. The main strengthening mechanism for the UFC processed X65 pipeline strip is composed by grain refining strengthening， solid solution strengthening， dislocation strengthening and precipitation strengthening， where the strengthening contributed by nano-sized precipitations is 96.1MPa. References | Related Articles | Metrics

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Study on Recrystallization and Precipitation Behavior of Cold-Rolled Low-Alloy High Strength Steel LI Zhi-hong， REN Jia-kuan， HUO Jian-sheng， LI Jian-ping 2019, 40 (3):  339-344.  DOI: 10.12068/j.issn.1005-3026.2019.03.007 Abstract ( 701 )   HTML   PDF (1881KB) ( 784 )   The kinetics of recrystallization in cold-rolled low-alloy high strength steel was studied by thermal simulation test. A kinetic model of recrystallization was built based on JMAK equation， which provided a theoretical basis to control ferrite recrystallization and precipitation behavior. The results show that the recrystallization completion time is greatly decreased with increasing annealing temperature. For the same reduction of cold rolling， the initial bainite structure contains a higher dislocation density and storage energy during annealing. The recovery and recrystallization process are synchronously advanced at the heating rate of 80℃/s， and the residual deformation storage energy increases before recrystallization so that the ferrite recrystallization can be quickly completed. Moreover， after the new process， the precipitation size in the experimental steel is more uniform and the volume fraction is higher， which lead to a better performance of precipitation strengthening. References | Related Articles | Metrics

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Alkali Recovery from the Bayer Leaching Slag of High Alumina Fly Ash GONG Yan-bing， SUN Jun-min， ZHANG Ting-an， LYU Guo-zhi 2019, 40 (3):  345-350.  DOI: 10.12068/j.issn.1005-3026.2019.03.008 Abstract ( 665 )   HTML   PDF (811KB) ( 795 )   The dealkalization process of the Bayer leaching slag of high alumina fly ash was studied. The influences of ［n(C)/n(S)］(the molar ratio of CaO to SiO2)， reaction temperature， reaction time， liquid-solid ratio and alkaline concentration on dealkalization rate， and the effect of dealkalization process on the alumina leaching efficiency were investigated. The results indicated that the lime-adding method can realize the removal of sodium oxide from the Bayer leaching slag of high alumina fly ash and recover part of alumina. The recovery of sodium oxide and alumina is significantly affected by reaction temperature， but［n(C)/n(S)］ only affects the dissolution of sodium oxide. The alkali removal ratio and alumina recovery ratio are 91.2% and 28.0% respectively under the conditions of 260℃， NaO concentration less than 80g/L， liquid-solid ratio 4， ［n(C)/n(S)］ 1.8 and reaction time 2h. The phase of Bayer leaching slag transforms from sodium aluminosilicate hydrate to hydrogarnet in the dealkalization process. References | Related Articles | Metrics

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Research on Technological Mineralogy of Copper Oxide Ore in Luanshya， Zambia WANG Gai-rong， YANG Hong-ying， TONG Lin-lin， LIU Yuan-yuan 2019, 40 (3):  350-355.  DOI: 10.12068/j.issn.1005-3026.2019.03.009 Abstract ( 761 )   HTML   PDF (4382KB) ( 706 )   The copper oxide ore in Luanshya， Zambia， is an unexplored mining area with large reserves of ore resources， which belongs to low-grade and refractory deposit. In order to develop and utilize the refractory resources， the technological mineralogy investigation was carried out by chemical analysis， XRD， microscopy， SEM-EDS and other testing methods. The results showed that in the ore， the ratio of the particles more than 212μm， from 125 to 212μm， from 74 to 125μm， less than 74μm is 30.13%， 13.80%， 17.00%， 39.07%， respectively. There are four occurrence state types of copper in the ore: copper in mineral state， isomorphic copper， adsorbed copper， and a few copper in colloid co-precipitation. Among them， the copper in mineral state mainly exists in the form of malachite， chrysocolla and pseudo-malachiter. The isomorphic copper is mainly in the form of biotite， chlorite and muscovite. Adsorbed copper mainly exists in limonite. Colloid co-precipitated copper mainly exists in the cemented body of feldspar-quartz-copper-iron. References | Related Articles | Metrics

Mechanical Engineering

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Ultrasonic and Electrorheological Integrated Polishing Process ZHANG Lei， HOU Han， HAN Yan-jun， WANG Xin 2019, 40 (3):  356-359.  DOI: 10.12068/j.issn.1005-3026.2019.03.010 Abstract ( 662 )   HTML   PDF (432KB) ( 715 )   An ultrasonic and electrorheological integrated polishing process was proposed for finishing micro structures of mold based on both the aggregation of abrasives caused by electrorheological effect and the driving effect of ultrasonic vibration on abrasives. An ultrasonic and electrorheological integrated polishing system was developed. The orthogonal test results showed that the amplitude of the ultrasonic vibration and the applied electric field strength have the greatest influence on surface roughness. The influence of ultrasonic and electrorheological integrated polishing process parameters on the surface roughness after polishing was studied by the single factor test. The experimental results verify the feasibility of the ultrasonic electrorheological integrated polishing process， which lays a foundation for subsequent process optimization and practical application. References | Related Articles | Metrics

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Reliability Analysis of Wear Gradient of Automobile Parts YANG Zhou， HU Quan-quan， ZHANG Yi-min， GUO Bing-shuai 2019, 40 (3):  360-364.  DOI: 10.12068/j.issn.1005-3026.2019.03.011 Abstract ( 802 )   HTML   PDF (609KB) ( 703 )   To study the reliability of automobile parts under the influence of abrasion， the biggest wear loss is taken into account in the gradual changing reliability model and the model of reliability state with the changing of time is obtained. Then， the secondary moment and the random perturbation method are adopted to give a quantitative analysis of the gradual changing reliability and the sensitivity. Finally， the effectiveness of the proposed method is confirmed by an example and the Monte Carlo. The fitting curves of the regularities of distribution of reliability and of sensitivity with abrasion are obtained， which can well reflect the change of reliability of dangerous sections of automobile parts in wear conditions and provide references for the gradual changing reliability with abrasion. References | Related Articles | Metrics

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Fatigue Robustness and Lightweight Design of Driving Axle Housing for Heavy Truck FAN Li ， XIE Li-yang， ZHANG Na 2019, 40 (3):  365-369.  DOI: 10.12068/j.issn.1005-3026.2019.03.012 Abstract ( 846 )   HTML   PDF (374KB) ( 879 )   Lightweight of driving axle housing is of great importance to enhance load capacity and reduce production cost. In this paper， multi-objective optimal model was built on the basis of finite element and fatigue analysis of driving axle housing. The orthogonal test table was established as parametric design of driving axle housing. The fatigue robustness and lightweight of the driving axle housing were optimized by Taguchi method and comprehensive evaluation method. The optimization result shows that this method can be applied to the multi-objective optimization of driving axle housing. The optimized driving axle housing has a better performance in fatigue robustness with light weight. The material of driving axle housing is saved， the production and operating cost is reduced， and the design level is thus improved. References | Related Articles | Metrics

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Optimization of Welding Process Parameters Based on Kriging-PSO Intelligent Algorithm MA Xiao-ying， SUN Zhi-li， ZHANG Yi-bo， ZANG Xu 2019, 40 (3):  370-375.  DOI: 10.12068/j.issn.1005-3026.2019.03.013 Abstract ( 724 )   HTML   PDF (2092KB) ( 909 )   Welding process parameters are the key factors affecting the quality of welding. Since the relationship between process parameters and the mechanical properties of welded joints is multi-dimensional and implicit， an optimization algorithm combining Kriging model and particle swarm optimization is proposed to optimize the process parameters of 3.5mm magnesium alloy sheet in AC_TIG welding. Firstly， the sample set is constructed by Taguchi orthogonal method. Secondly， the Kriging surrogate model is established between output and input， and then the optimal combination of process parameters and its mechanical properties are obtained by the proposed algorithm. The results show that such optimal process parameters as tensile strength， yield strength and average micro-hardness of the welded joints reach 97.6%， 98% and 91.5% of the base metal respectively. The proposed algorithm not only reduces economic and time costs， but also improves the welding process design capabilities. References | Related Articles | Metrics

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Performance of Magneto-Rheological Brake Based on Braking Controller SONG Wan-li， WANG Si-yuan， HU Zhi-chao， ZHANG Meng 2019, 40 (3):  375-380.  DOI: 10.12068/j.issn.1005-3026.2019.03.014 Abstract ( 680 )   HTML   PDF (983KB) ( 664 )   The braking performance of MRB(magneto-rheological brake)based on braking controller was mainly explored in this paper. The main research contents included design and structural optimization to obtain the optimum MRB. In order to study its braking performance，the MRB controller was designed based on the Arduino board and the L9349 power driver IC. Deceleration experiment and braking torque following experiment with different step signals and sine signal were carried out for exploring braking performance. The results indicate that the MRB′s response time is about 40ms，the delay time is about 70ms，and the lag braking time is about 20ms in the following process that was faster than that of the hydraulic braking system. This study may has great significance with laying a foundation for the development and application of MRB. References | Related Articles | Metrics

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Mesh Stiffness Analysis of Planetary Gear System with Gear Tip Relief MA Hui， DUAN Tian-tang， SUN Yan-ning， CHEN Kang-kang 2019, 40 (3):  380-385.  DOI: 10.12068/j.issn.1005-3026.2019.03.015 Abstract ( 797 )   HTML   PDF (2745KB) ( 775 )   Taking the planetary gear system as the research object， which contains lightening hole of sun gear， pin support of ring gear and the flexible carrier arm， a finite element model of planetary gear system with gear tip relief was established on the basis of ANSYS software. Based on the model， the influence of the gear tip relief and gear structure， such as lightening hole of sun gear， the rim thickness of ring gear and the flexible carrier arm， on the mesh stiffness was analyzed. The results show that the gear tip relief changes the shape and value of the mesh stiffness curve. Mesh stiffness decreases with the increase of lightening hole size. However， with the increase of the backup ratio of ring gear， the mesh stiffness increases gradually. Meanwhile， the more flexible the carrier arm is， the smaller the gear meshing stiffness fluctuates. The research results may provide a theoretical basis for the design of planetary gear system considering gear modification in actual production. References | Related Articles | Metrics

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Experiment of Grinding Surface Quality and Subsurface Microstructure for Nickel-Based Single Crystal Superalloy CAI Ming， GONG Ya-dong， QU Shuo-shuo， YANG Yu-ying 2019, 40 (3):  386-391.  DOI: 10.12068/j.issn.1005-3026.2019.03.016 Abstract ( 696 )   HTML   PDF (1488KB) ( 717 )   The orthogonal experiments were conducted to carry out the research of surface quality influential factors for nickel-based single crystal superalloy DD5 and subsurface microstructure in grinding. The orthogonal experiment of DD5 plane slot grinding was conducted. The influence of grinding wheel linear speed， grinding depth and feed rate on grinding surface quality was concluded， and the optimized parameters combination was also selected. The grinding subsurface microstructure and debris morphology were observed then. The results show that: the grinding wheel linear speed has the greatest influence on the grinding surface roughness R○a; with the increase of grinding wheel linear speed， the grinding surface roughness Ra decreases;with the increase of grinding depth and feed rate， the grinding surface roughness Ra increases. The optimized parameters combination of nickel-based single crystal superalloy DD5 within the experimental parameters in plane grinding is as the following: grinding wheel linear speed is 30m/s， grinding depth is 20μm and feed rate is 0.2m/min. The plastic deformation layer and the machined hardening layer appear on the grinding subsurface. The grinding debris mainly presents the serrated features. References | Related Articles | Metrics

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Simulation Experiment of Grinding Temperature for Novel Point Grinding Wheel YIN Guo-qiang， GONG Ya-dong， LI You-wei， WANG Fei 2019, 40 (3):  392-397.  DOI: 10.12068/j.issn.1005-3026.2019.03.017 Abstract ( 707 )   HTML   PDF (1121KB) ( 709 )   The wheel-workpiece contact zone is changed due to point grinding inclining angle α and novel grinding wheel with coarse grinding area angle θ. It changes from line contact into point contact in theory and the grinding zone temperature is also changed. In this paper，the grinding zone temperature is simulated by the finite element method. The orthogonal experiments L16(45)was designed and thermocouple measurement was used for grinding experiments. Through range analysis， primary and secondary factors affecting grinding temperature is that coarse grinding area angle θ>cutting depth a○p>inclining angle α>axial feeding speed v○f>grinding wheel speed v○s. The optimum parameters combination of reducing the grinding zone temperature is that θ(20°)， a○p(0.01mm)，α(1°)，v○f(0.6mm/min)，v○s(35m/s). Finally，by means of single factor experiments， the correctness of the simulation was verified and the influence of each parameter on grinding zone temperature was deeply analyzed. References | Related Articles | Metrics

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Integrated Variable Gain LQR Control of Seat Suspension and Automobile Suspension GUO Li-xin， CHEN Cong-gen， ZHAO Lin 2019, 40 (3):  398-403.  DOI: 10.12068/j.issn.1005-3026.2019.03.018 Abstract ( 630 )   HTML   PDF (1485KB) ( 836 )   Based on the fuzzy control theory and optimal control theory， an integrated variable gain LQR(linear quadratic regulator)control method based on fuzzy control for vehicle active suspension and seat active suspension is proposed. Based on the establishment of "car-chair" three-degree-of-freedom dynamics model， taking the vertical acceleration of vehicle body and seat vertical acceleration as the control target and the dynamic displacement of the wheel and the range of vehicle suspension motion less than the specified value as the constraint conditions， the vehicle suspension and seat suspension variable gain LQR controller is designed， and the simulation experiment analysis and the comparison with Matlab/Simulink are carried out， whose results indicate that this control method has better control effect on seat suspension and vehicle suspension， and the validity and feasibility of the integrated variable gain LQR control method are verified， which could provide a reference for the future research of suspension system control. References | Related Articles | Metrics

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An Energy-Saving Scheduling Algorithm for Non-identical Parallel Machines with Multi-resource Contraints ZHOU Bing-hai， GU Jia-ying 2019, 40 (3):  403-408.  DOI: 10.12068/j.issn.1005-3026.2019.03.019 Abstract ( 638 )   HTML   PDF (544KB) ( 768 )   A modified immune clone selection algorithm is proposed for the non-identical parallel lithography machine scheduling problem of the bottleneck process with energy consumption， changeover time and resource constraints， where multiple reticles are available for each reticle type. Firstly， the scheduling problem domain is described and mathematical programming formulations are put forward with the objective function of minimizing both the total weighted completion time and the energy consumption. Based on the model， then a modified multi-objective immune clone selection algorithm with elitist strategy is developed. In addition， the depth neighbor search and the population renewal operator are combined to the algorithm to increase and balance the exploration and exploitation ability. Finally， simulation experiments and theory analysis are carried out to evaluate the as-proposed algorithm， and the results indicate that the algorithm is valid and feasible. References | Related Articles | Metrics

Resources & Civil Engineering

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Distribution Law of Granular Lateral Pressure in Caved Ore-Rock with Limited Width HE Rong-xing， REN Feng-yu， TAN Bao-hui， LIU Yang 2019, 40 (3):  409-413.  DOI: 10.12068/j.issn.1005-3026.2019.03.020 Abstract ( 681 )   HTML   PDF (1703KB) ( 590 )   The lateral pressure of caved ore-rock in metal mine has a significant effect on supporting the surrounding rock and controlling the rock mass movement. Taken the caved ore in Gongchangling Iron Mine as an example， the distribution law of the granular lateral pressure in the caved ore-rock with the limited width was studied. The experiment results show that the static lateral pressure was nonlinear increase with granular buried depth increase， the formula of granular pressure changed with buried depth and angle was obtained by regression based on the theory of dimensional harmonious principle. In the case of no backfill， the granular lateral pressure decreases with the increase of the discharge amount， the range of drawing increasing can accelerate the decreased speed of granular lateral pressure. The pressure values of the lower four measuring points decrease with the drawing amount， and the pressure values of the upper four measuring points increase. The break variable of lateral pressure at hanging wall is lower than the value at footwall， and the drawing amount has less influence on the lateral pressure of hanging wall. That is to say that the drawing amount has limited influence range on the granular lateral pressure in height and width under the condition of backfill. This achievement has guiding significance for revealing the pressure bearing mechanism and application in the mine engineering of granular. References | Related Articles | Metrics

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Temperature Field Simulation of Fuyu Oil Shale Pyrolysised by High Voltage Industrial Frequency Technology ZHAO Shuai， SUN You-hong， LIU Shi-chang， LI Qiang 2019, 40 (3):  414-419.  DOI: 10.12068/j.issn.1005-3026.2019.03.021 Abstract ( 613 )   HTML   PDF (2834KB) ( 685 )   Using the high voltage industrial frequency current to heat oil shale， the plasma channels can be formed in oil shale. The in-situ cracking of oil shale is realized by heating the oil shale with the generated plasma and the carbonized inner surface of the conductive channel. In this paper， a three-dimensional coupled model of oil shale was established by finite element analysis software， and the distribution of temperature field during the high frequency oil shale pyrolysis was obtained by numerical calculation. When the voltage is 1000V and the current is 5A， the temperature at the center of electrode， after 6 minutes heating， reached 597℃， and the temperature at the areas around the electrode 30mm away reached 347℃， meeting the pyrolysis demand of oil shale. With the increase of current， the increased temperature of oil shale during the same heating time showed a steady rise， and the range of effective pyrolysis also went up. According to the results of numerical simulation， using the high voltage industrial frequency to heat oil shale can gain a fast heating rate and high energy efficiency. References | Related Articles | Metrics

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An Improved Fish Swarm Clustering Algorithm for Structural Grouping WANG Shu-hong， REN Yi-peng， CHEN Jun-zhi ， ZHANG Zi-shan 2019, 40 (3):  420-424.  DOI: 10.12068/j.issn.1005-3026.2019.03.022 Abstract ( 561 )   HTML   PDF (1232KB) ( 698 )   Aiming at the shortcomings of the conventional classification method of structural plane production， a new structural plane classification algorithm was proposed. Based on the structural plane classification of K-Means algorithm， the AFSA-RSK structural surface classification algorithm is established by combining the artificial fish swarm algorithm(AFSA)with the K-Means algorithm. The powerful optimization ability of the fish swarm algorithm is used to replace the K-Means algorithm to search for the structural surface set， and clustering by K-Means algorithm. After the clustering is completed， the corresponding parameters are selected to evaluate the clustering effect. According to the existing problems， the step size and visual field of the fish swarm algorithm are modified， the accuracy of finding the cluster is improved， and the clustering process is dynamically adjusted. Comparing the improved AFSA-RSK algorithm with other algorithms， it can be obtained that the improved AFSA-RSK algorithm is better in iterative speed， clustering precision and memory ratio， and it is more suitable for application in structural plane grouping. References | Related Articles | Metrics

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Durability Risk Assessment of Stay Cables Based on Cloud Theory LIANG Li， XING Guan-hua， WU Feng-yuan 2019, 40 (3):  425-429.  DOI: 10.12068/j.issn.1005-3026.2019.03.023 Abstract ( 591 )   HTML   PDF (484KB) ( 648 )   Reasonable evaluation of risk can effectively avoid accidents and provide forward-looking opinions for the project safety. A spatial risk analysis method based on cloud theory and ALARP criterion was proposed. First of all， "predictability" is introduced as a risk index to establish a three-dimensional risk space. Subsequently， the concept of "the risk interface" is defined， and the interface equation is established based on the level of the risk index. By modifying the variable coefficient， the risk space shape is adjusted to realize the empowerment of risk indicators under different assessment needs. Finally， the cloud models of risk space and evaluation sample are established according to the principle of cloud theory. Based on sample cloud model， a large number of cloud drops are generated and brought into normal cloud generator to calculate average certain degree， which is a basis for determining the final risk rating. It realizes the complete quantification of the risk assessment process. The consistency and feasibility between this method and standard are verified by taking durability risk evaluation as an example. References | Related Articles | Metrics

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Microsopic Experiment of Particle Trapping Process for Filter Screen YU Zhen-hui， LIU Jing-xian， CHU Yan-hao， TIAN Peng 2019, 40 (3):  430-435.  DOI: 10.12068/j.issn.1005-3026.2019.03.024 Abstract ( 614 )   HTML   PDF (1847KB) ( 688 )   Due to its good particles trapping properties， filter screen is widely used in industrial or civil fields. However， the research on its micro-capture mechanism is still limited. In this paper， a set of microscopic observation system was set up to record the whole process of filter screen trapping particles. The microscopic performance of the process of particles trapping was studied. The influencing factors that affect single fiber filtration and mesh bridging blockage were analyzed. The results show that with the increase of filtration velocity， the ratio of unblocked pore area to total pore area gradually decreases， and eventually a stable state will appear. With the increase of mesh number， the ratio gradually decreases. In the actual application， the filtration velocity and filter screen pore size should be properly selected according to the specific conditions of use. The filter screen should be cleaned in time to avoid secondary pollution. References | Related Articles | Metrics

Management Science

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Haze Decoupling Effect Under the Constraints of Environmental Regulation in Liaoning Province YU Guan-yi， XIU Chun-liang， ZHAO Chang-song 2019, 40 (3):  435-440.  DOI: 10.12068/j.issn.1005-3026.2019.03.025 Abstract ( 889 )   HTML   PDF (570KB) ( 661 )   Based on the statistical and satellite remote sensing data of 57 regions in Liaoning Province from 2006 to 2015a， the spatial Durbin model was used to test the spatial effect of government and market environment regulation tools on the decoupling of industrial development and haze in the neighboring regions. The results of spatial autocorrelation showed that haze decoupling in Liaoning Province presents a spatial positive correlation， and most of the regions are absolutely and relatively decoupled. The empirical results show that due to the low resource tax cost and effective supervision of local governments on the environmental responsibility of large enterprises， the government′s environmental regulation effect is better than the market environmental regulation; the demonstration effect and atmospheric movement have brought positive guidance and ripple effects to the neighboring regions. References | Related Articles | Metrics

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Design and Optimization of Competitive Product Channel Structure Based on Revenue Sharing Contract ZHANG Shu-hua ， DU Xiao-jun ， ZHOU Bao-gang 2019, 40 (3):  441-446.  DOI: 10.12068/j.issn.1005-3026.2019.03.026 Abstract ( 590 )   HTML   PDF (456KB) ( 596 )   Three types of channel structure composed of two competitive suppliers and two network platforms are designed. The channel selection strategy is analyzed based on the joint substitution rate of products and channels when the supplier and the network platform act as decision makers， respectively. After establishing the revenue sharing contract from the network platform to the supplier， the influence of the joint substitution ratio and revenue sharing ratio on the optimization of the multi-channel supply chain structure is further studied. It is found that the dominant strategy of the platform is to set up an exclusive deal with the supplier and the supplier will choose the multi-channel strategy. Therefore， in the basic channel structure there is no equilibrium solution. That all participants form an exclusive deal is a balanced strategy after the revenue sharing contract is established. The results of the study are of guiding significance to different decision-makers for channel structure selection and optimization in the multi-channel supply chain environment. References | Related Articles | Metrics

物理学

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Analysis and Modeling of Electro-osmosis Based on the Modified Poisson-Boltzmann Equation HU Sheng， LYU Jiang-tao， SI Guang-yuan 2019, 40 (3):  447-451.  DOI: 10.12068/j.issn.1005-3026.2019.03.027 Abstract ( 896 )   HTML   PDF (664KB) ( 1098 )   The ion distribution for different concentrations and applied voltage is studied by modeling the ion distribution in electric double layer(EDL)based on the Poisson-Boltzmann(PB)and modified Poisson-Boltzmann(MPB)equations. The results indicate that some errors exist in the thickness of diffusion in EDL if the applied voltage is more than 0.4V and the ion concentration is less than 10-4mol/L. The simulated electro-osmotic flow by using Debye length is not in agreement with the practical observation result mainly because the Debye-Hückel equation is of linear relationship and not compatible with the calculating electro-osmotic flow under higher voltage conditions. By use of the MPB equation with non-linear characteristics， the maximal electro-osmotic flow generated by two co-planar metal electrodes with the width of 500μm and the gap of 25μm is 1034.31μm/s at ±1V potential with the frequency of 500Hz. References | Related Articles | Metrics

Biologic Engineering

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Effect of Celecoxib on Electrophysiological Property of Cardiac Sodium Channel Nav1.5 SUN Jian-fang， XU Yi-jia， WANG Zhan-you 2019, 40 (3):  452-456.  DOI: 10.12068/j.issn.1005-3026.2019.03.028 Abstract ( 959 )   HTML   PDF (525KB) ( 623 )   The effect of celecoxib on electrophysiological property of Nav1.5 was studied，which was associated with cardiac toxicity. The effects of celecoxib on the electrophysiological properties of Nav 1.5， including peak current， voltage-dependent activation， voltage-dependent inactivation and recovery kinetics， were investigated by whole cell patch clamp technique. The results showed that celecoxib inhibited the peak currents of Nav1.5 in a concentration-dependent manner with a calculated IC50 value of 1.54×10-8mol/L. Moreover， celecoxib promoted the activation and inactivation phase of Nav1.5， making it somewhat difficult to recover from the inactivation to the resting state. The prominent inhibition of celecoxib on Nav1.5 indicated that there might be a close relationship between potential cardiovascular risks and Nav1.5. References | Related Articles | Metrics