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    Information & Control
    A Genetic Algorithm for Stateful Service Selection
    ZHAO Xiu-tao, ZHANG Bin, SUN Ruo-nan, GE Liang
    2015, 36 (1):  1-5.  DOI: 10.12068/j.issn.1005-3026.2015.01.001
    Abstract ( 750 )   HTML   PDF (537KB) ( 979 )  
    Tasks in the workflow of an application are generally considered to be independent of each other in current web service selection based on QoS. In practice, however, state information is often shared among some tasks in the workflow, which adds binding constraints between tasks and web services, resulting in higher time complexity and lower selection efficiency. Aiming at drawbacks of the existing methods, a genetic algorithm for stateful service selection was proposed. In the proposed algorithm, genetic operations including crossover and mutation were redefined in order to make all individuals meet state-correlate binding constraints among tasks. In addition, to prevent premature convergence, penalty function was introduced into individual evaluation strategy; moreover, similarity judgment between individuals was also included in the algorithm.The experiments results showed that with regards to stateful service selection, good solution and fast convergence rate can be obtained using the proposed algorithm; furthermore, the proposed algorithm is more efficient than the existing algorithms.
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    The Blind Source Separation for Speech Signal Based on Pearson System
    JI Ce, LIU Meng-die, TAO Yi-ming
    2015, 36 (1):  6-9.  DOI: 10.12068/j.issn.1005-3026.2015.01.002
    Abstract ( 664 )   HTML   PDF (599KB) ( 1167 )  
    The same activation function is always used to separate all speech signals by means of the conventional natural gradient algorithm. Although blind source separation can be achieved, the separation effect is not ideal. To solve this problem, sub-band activation function was used based on Pearson system to improve natural gradient algorithm. By introducing Pearson system, the Pearson function with conventional activation function was combined. The appropriate activation function was selected according to the method of moments-estimating in each part. Then the selected activation function was brought into the separation matrix. This algorithm effectively overcomes the shortcomings and deficiencies of the conventional separation algorithm for speech signal. The simulation results showed that the performance of the improved algorithm is superior to that of the conventional natural gradient algorithm in the actual speech signal separation. In addition, the mean square error is reduced greatly and good convergence rate is maintained at the same time.
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    QoE Quantification Method Based on Multipath Transmission
    BAO Ying, LEI Wei-min, DAI Ming-zhu, GUAN Yun-chong
    2015, 36 (1):  10-14.  DOI: 10.12068/j.issn.1005-3026.2015.01.003
    Abstract ( 821 )   HTML   PDF (840KB) ( 970 )  
    QoE model quantification methods specification based on multipath transmission has not yet formed, so most research has focused on the default routing QoE quantification and evaluation methods of bearer network. To solve this problem, a multipath transmission QoE quantification method was proposed. In the research,it was pointed to QoE quantification affecting factors according to network performance indicators of multipath transmission. And then, multipath transmission QoE quantification calculations were explained in detail. At the same time, the design process of the proposed model was given, including QoE quantification model formula specification, QoS performance indicators selection, human factors parameters setting and the scoring rules setting. Finally, the effectiveness of multipath transmission QoE quantification method was demonstrated by OMNeT++ simulation experiments. The multipath transmission mode QoE quantification problem can be solved by this algorithm, whose superiority is also effectively demonstrated.
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    Optimization of Link Scheduling Based on Expansion Graph in WiMAX Wireless Mesh Networks
    CHEN Jian, JIA Jie, WEN Ying-you, ZHAO Da-zhe
    2015, 36 (1):  15-19.  DOI: 10.12068/j.issn.1005-3026.2015.01.004
    Abstract ( 711 )   HTML   PDF (607KB) ( 811 )  
    Link scheduling is a key problem in the design of WiMAX WMN. To maximize the network throughput, an optimal interference-free link scheduling model was presented.For link list with equal slot demand, a heuristic link scheduling algorithm was proposed for WiMAX WMN. Furthermore, as the relay characteristics of WMN, an expansion graph model was designed on the basis of node and link decomposition. By detailing the transfer process, the ratio of the slot spatial reuse was enhanced, resulting in satisfying the link scheduling demand with single and multiple transmissions. Extensive simulation results showed that the network scheduling cycle can be effectively reduced, and the network throughput can also be improved.
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    An Adaptive Clustering Method on Medical Short Text
    LI Wei, XU Hong-tao, ZHAO Da-zhe, LIU Ji-ren
    2015, 36 (1):  19-23.  DOI: 10.12068/j.issn.1005-3026.2015.01.005
    Abstract ( 857 )   HTML   PDF (832KB) ( 1211 )  
    An adaptive clustering method on short text was presented for synonyms text recognition and disease naming standardization of diagnosis in electronic medical record. Firstly, a new set based text similarity measure algorithm was proposed. Then, a similarity distribution based text clustering algorithm which could automatically determine the number of clusters was applied to recognize the synonymous disease texts. Finally, the disease naming texts were standardized by the central concept extraction algorithm based on frequent sequence pattern, while clusters were merged and optimized to further improve the clustering accuracy. The results showed that the proposed approach has a high accuracy and clustering efficiency which is of great significance for medical application such as medical text preprocessing, classification and analysis.
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    Materials & Metallurgy
    Microstructure Evolution of Low Carbon Si-Mn Steel During Direct Quenching and Isothermal Partitioning
    KANG Jian, YUAN Guo, ZHANG He, WANG Guo-dong
    2015, 36 (1):  24-28.  DOI: 10.12068/j.issn.1005-3026.2015.01.006
    Abstract ( 720 )   HTML   PDF (1290KB) ( 949 )  
    Compression deformation was introduced into the conventional quenching and partitioning process for low carbon Si-Mn steel.Effects of the hot deformation on microstructure evolution and microstructure characteristics of specimens treated by various isothermal partitioning processes were investigated. The results showed that the microstructure is refined and the fraction of high-angle grain boundary increases from 65.7% to 72.5% due to the hot deformation. Carbon-rich areas formed during transformation and partitioning process are mostly observed at the boundaries of prior austenite grains and martensite laths. With the increase of the partitioning time,the microstructure shows a tendency to tempering transformation. When the partitioning time is up to 1500s, a great number of carbides are formed and the volume fraction of retained austenite decreases to 7.9%.
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    Hydrogen Embrittlement Behavior of SA508-Ⅲ Steel
    LIU Jia-hua, WANG Lei, LIU Yang, SONG Xiu
    2015, 36 (1):  29-33.  DOI: 10.12068/j.issn.1005-3026.2015.01.007
    Abstract ( 860 )   HTML   PDF (2521KB) ( 914 )  
    The gas phase thermal charging method was performed for SA508-Ⅲ steel with H charging at high temperature and high pressure. The interaction between H and the tensile deformation behavior was studied at room temperature to clarify the hydrogen-induced brittleness mechanism and provide the basic data for the steel design of nuclear power plant. The results showed that the yield strength of the steel with H charged slightly increases, and the reduction area obviously decreases. The fracture morphology changes from normal micro-void coalescence fracture to mixture of river pattern and dimple fracture due to H charging. The increase of the yield strength ascribes to the pinning effect of H on dislocation,thus the initiation of dislocation can be resisted.During the plastic deformation process, H moves following the moving dislocations and concentrates at the interfaces between the carbides and matrix. Once H concentration reaches the critical value, the bonding force between the carbides and matrix decreases, resulting that the ductility of the steel decreases.
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    Experimental Study on Liquid Precipitation of Iron Vanadate
    GAO Qiang, SHI Pei-yang, LIU Cheng-jun, JIANG Mao-fa
    2015, 36 (1):  33-37.  DOI: 10.12068/j.issn.1005-3026.2015.01.008
    Abstract ( 943 )   HTML   PDF (5948KB) ( 1422 )  
    Crystalline FeVO4 was prepared by liquid precipitation. The effects of pH value and reaction temperature on precipitates were investigated by X-ray diffraction(XRD)and scanning electron microscopy(SEM). The results indicated that crystalline FeVO4 with regularly spherical in the shape and fine grain size is obtained under the conditions of reaction temperature at 25℃, pH value of 1.5~2, n(V)/n(Fe)=1, and the standing time of 60 min. With the increase of pH value, Fe2O3 phase appears, and FeVO4 phase disappears. The temperature affects greatly on the preparation of iron vanadate, and once the temperature increases, the pH value needs to be adjusted.
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    Corrosion Process of Ferritic Stainless Steel in Hydrochloric Acid Solution
    XIE Qiong, SHI Pei-yang, JIANG Mao-fa
    2015, 36 (1):  38-42.  DOI: 10.12068/j.issn.1005-3026.2015.01.009
    Abstract ( 973 )   HTML   PDF (764KB) ( 1597 )  
    The corrosion process of ferritic stainless steel in hydrochloric acid solution was researched by electrochemical workstation and microstructure analysis. The results showed that the corrosion process of ferritic stainless steel in hydrochloric acid solution includes three periods: penetrating of ions into the passive film, thickening of corrosion production film and equilibrium of polarizing reactions. Uniform corrosion is the only way found in the periods of penetrating the passive film and thickening of corrosion production film, while abundant intercrystalline corrosion and a few pitting corrosions appear in the period of equilibrium of polarizing reactions. When the hydrochloric acid is above 10%, the corrosion process is completely controlled by the anodic reactions and the passive zone totally disappeared. Both the solution resistance Rs and the charge-transfer resistance Rt decrease with the increase of the concentration of hydrochloric acid, meanwhile the capacities of charging and discharging of the electric double layer in the surface of the stainless steel anode do not change obviously.
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    The Activity Model and Thermodynamic Analysis for Ti-Bearing Blast Furnace Slag
    SHI Jun-jie, LI Jie, SUN Li-feng, JIANG Mao-fa
    2015, 36 (1):  43-47.  DOI: 10.12068/j.issn.1005-3026.2015.01.010
    Abstract ( 869 )   HTML   PDF (584KB) ( 682 )  
    Based on the coexistence theory of molecules and ions in slags, an activity model of CaO-SiO2-MgO-Al2O3-TiO2 was constructed, and the calculated result was in good agreement with experimental data. Combined with the phase diagram, the activity model was used to calculate the influences of slag basicity and w(TiO2) on the activities of the main components in slag. The calculated result indicates that the component containing TiO2 is mainly CaO·TiO2, and the activity of CaO·TiO2 is 0.18 at 1500°C. The activity of CaO·TiO2 increases first and then decreases with the increase of w(TiO2) and basicity. It is better for the increase of activity of CaO·TiO2 when the basicity is between 1.08 and 3.08 and w(TiO2) is between 26% and 43%, which is benefit for the enrichment of titania as CaO·TiO2.The corresponding basicity for maximum activity of CaO·TiO2 increases with the increase of w(TiO2), and the basicity is between 1.34 and 1.63 when w(TiO2) is between 20% and 28%, while the maximum enrichment of titania as CaO·TiO2 can be obtained.
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    Experimental Study on Separation of Iron from Low m(Cr)/m(Fe) Chromite
    ZHAO Qing , ZHANG Bo, LIU Cheng-jun, JIANG Mao-fa
    2015, 36 (1):  47-51.  DOI: 10.12068/j.issn.1005-3026.2015.01.011
    Abstract ( 807 )   HTML   PDF (798KB) ( 1641 )  
    Based on thermodynamic analysis, some experiments on separation of iron from low m(Cr)/m(Fe) South Africa chromite by carbothermic reduction were conducted. It was found that the separation result of iron from chromite was notably influenced by reduction temperature, and the experimental optimum reduction temperature was 1100℃. Below 1100℃, the reduction precipitation and matrix interacted by embedding.Above 1100℃, the reduction degree of chromium rose sharply, leading the recovery yield of chromium get worse. Metallurgical-grade chromite was obtained from chemical-grade chromite by 0.5h reduction at 1100℃ and an acid leaching treatment. Furthermore, the m(Cr)/ m(Fe) was elevated from 1.7 to 5.8 with only a minor loss of chromium after 2h reduction at 1100℃. The study on the separation of iron from low m(Cr)/m(Fe) chromite may provide a new idea for comprehensive utilization of chromite.
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    Experimental Study on Preparation of Oxidized Barun Iron Ore Pellets with Boron-Bearing Iron Concentrate Addition
    FU Xiao-jiao, CHU Man-sheng
    2015, 36 (1):  52-56.  DOI: 10.12068/j.issn.1005-3026.2015.01.012
    Abstract ( 554 )   HTML   PDF (944KB) ( 762 )  
    Under laboratory conditions, experiments on the effect of boron-bearing iron concentrate on the preparation process and metallurgical properties of oxidized Barun iron ore pellets were carried out. The results show that, when the additional addition of boron-bearing iron concentrate is 5.0%, the oxidized iron ore pellets with 40% Barun iron ore content can meet the requirements of blast furnace smelting. Boron-bearing iron concentrate can increase the crushing strength of pellets and decrease the reduction swelling rate. With increasing the additional addition of boron-bearing iron concentrate from 0 to 7.5%, the crushing strength is raised from 2630 N to 3709N, the reduction swelling rate is decreased from 25.69% to 15.53%. When the additional addition of boron-bearing iron concentrate is 7.5%, the pellets roasting temperature can be decreased from 1200℃ to 1150℃, and the quality of the oxidized Barun iron ore pellets can still meet the requirements of blast furnace smelting.
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    Hearth Erosion Monitoring Model of Blast Furnace Based on Boundary Movement Method
    LI Qiang, FENG Ming-xia, CHU Wen, ZOU Zong-shu
    2015, 36 (1):  57-62.  DOI: 10.12068/j.issn.1005-3026.2015.01.013
    Abstract ( 800 )   HTML   PDF (673KB) ( 961 )  
    A hearth erosion monitoring model for blast furnace was proposed based on the temperature data from the embedded thermocouples in the blast furnace hearth, and combining the numerical heat transfer calculation and gradient descent method of optimization theory to find the optimum boundary moving step length factor. The unknown-boundary inverse heat-transfer problem can be effectively solved with the model. Using the monitoring temperature data from thermocouples as input, the hearth inner lining erosion profile and residual thickness were computationally obtained by the proposed model through solving the unknown-boundary heat-transfer problem. Taking the collected known hearth erosion profiles and the corresponding temperature data from thermocouples as check samples, the comparison shows that the average relative error of the model prediction is about 3.6%, and the reliability of the model is thus confirmed.
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    Experimental Study on Direction Reduction of Vanadium-Bearing Titanomagnetite
    SUN Yu, DONG Yue, ZHENG Hai-yan, SHEN Feng-man
    2015, 36 (1):  63-67.  DOI: 10.12068/j.issn.1005-3026.2015.01.014
    Abstract ( 800 )   HTML   PDF (637KB) ( 950 )  
    The direct reduction behavior of vanadium-bearing titanomagnetite pellets containing coal was experimentally studied in laboratory based on thermodynamic analysis. The reduction mechanism and influences of reduction temperature, reduction time,and the xC/xO on metallization ratio were investigated. The results showed that direct reduction iron (DRI) can be obtained in this process, while titanium exists as the form of titanium oxide in the slag. With the increase of reduction temperature, the metallization ratio increases quickly first and then slowly. For carbon-containing pellets with 0.9 of xC/xO, the metallization ratio reached the highest at 20min and DRI was re-oxidized after 20 min. When the xC/xO in the pellets was 1.1∶1, no re-oxidization happened within 40min. With less coal addition (0.8 of xC/xO), there were similar phenomena with that of 1.1 of xC/xO and the metallization ratio was up to 90 % at 1300℃ after 10min.
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    Study on Catalyst of Bio-oil Model Steam Reforming for Hydrogen Production
    YU Qing-bo, LI Xin-hui, XIE Hua-qing, QIN Qin
    2015, 36 (1):  68-72.  DOI: 10.12068/j.issn.1005-3026.2015.01.015
    Abstract ( 561 )   HTML   PDF (626KB) ( 798 )  
    Continuous-adsorption enhanced bio-oil reforming process can produce hydrogen continuously and efficiently. Granular catalysts were prepared for the reforming process. Their catalytic performances with three different bio-oil models (ethanol, acetone and phenol) were investigated. The operating conditions were fixed as follow: the reforming temperature was 750℃, the mass ratio of water to carbon was 6∶1, and the loading capacity of catalyst was 10cm. The result shows that the addition of nickel can effectively promote the steam reforming reaction. Additives like magnesium, cerium, cobalt, et al can improve catalyst’s performance of anti-carbon-deposition. Mg-Ni/Co was the best nickel-based catalyst according to the experiments with different bio-oil models. In the experiment using simulated bio-oil with Mg-Ni/Co as catalyst, the hydrogen production rates with the three models were over 60%, 70% and 90% , respectively. Mg-Ni/Co has not only good stability, but also good regeneration performance.
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    Adsorption Kinetics of Methylene Blue on CaTiO3
    HAN Chong, YANG He, XUE Xiang-xin
    2015, 36 (1):  73-76.  DOI: 10.12068/j.issn.1005-3026.2015.01.016
    Abstract ( 645 )   HTML   PDF (465KB) ( 1004 )  
    The effects of CaTiO3 dosage, solution pH value,and initial methylene blue (MB) mass concentration on equilibrium adsorption rate of MB on CaTiO3 were experimentally investigated in detail. The adsorption isotherm of MB on CaTiO3 was also discussed. The results showed that CaTiO3 dosage has little effect on equilibrium adsorption rate of MB. The equilibrium adsorption rate of MB on CaTiO3 at the solution pH value of 7 is greater than that at the solution pH values of 4 and 10, suggesting that neutral condition is in favor of the adsorption of MB on CaTiO3. The equilibrium adsorption rate of MB on CaTiO3 decreases significantly with increasing initial mass concentration of MB. The adsorption of MB on CaTiO3 follows the Langmuir adsorption isotherm and the adsorption saturation capacity of MB on CaTiO3 is 1.64mg/g.
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    Study on Coal-Based Direct Reduction of High-Chromium Vanadium-Titanium Magnetite
    JIANG Tao, XU Jing, GUAN Shan-fei, XUE Xiang-xin
    2015, 36 (1):  77-81.  DOI: 10.12068/j.issn.1005-3026.2015.01.017
    Abstract ( 696 )   HTML   PDF (575KB) ( 893 )  
    High-chromium vanadium-titanium magnetite, reductant coal and binder were mixed and pressed into pellets, and then direct reduction of the pellets was conducted. The effects of coal types, COR, reduction temperature, reduction time and additive on the metallization rate of the reduction products were studied. The minerals of the reduction products were analyzed by X-ray diffraction. The results showed that, under the condition of anthracite, COR of 1.2, temperature of 1350℃, and reaction time of 60min, the maximum metallization rate is 89.80% without any additive. Under the condition of COR of 1.2, temperature of 1250℃, and reaction time of 30min, the maximum metallization rate is 85.27% with 3% CaF2 addition, showing that the energy consumption of the reduction process can be reduced. When the reduction temperature is lower than 1250℃, the main mineral of the product is metallic iron, and the others are small amounts of Fe2O3, Fe3O4, Fe3C, Fe0.5Mg0.5Ti2O5 and TiO2. When the temperature is 1300℃, Fe2VO4 appeared in the reduction products. When the temperature is 1350℃, (Fe, Cr) and Ti3O5 appeared in the reduction products.
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    Study on Electrodeposition Recovery of Copper and Cyanide from Cyanide-Containing Wastewater
    GAO Teng-yue, LIU Kui-ren, HAN Qing, XU Bin-shi
    2015, 36 (1):  81-85.  DOI: 10.12068/j.issn.1005-3026.2015.01.018
    Abstract ( 591 )   HTML   PDF (398KB) ( 798 )  
    The forms of copper cyanide species and the data of deposition and oxidation potentials in high-copper and high-cyanide wastewater were determined by thermodynamic calculation and laboratory experiments. The results confirm that copper cyanide species exist mainly as Cu(CN)3-4 and Cu(CN)2-3, where the former is dominant. The form of copper cyanide is significantly affected by temperature and pH. With suitable electrode materials, copper could be recovered and the decomposition of cyanide could be prevented effectively in the electrodeposition process. The maximum current efficiency exceeded 36%, and the concentration of free cyanide increased from 0.096mol/L to 0.316mol/L. The feasibility of treating high-copper and high-cyanide wastewater by electrodeposition is proved by the present experiments.
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    Mechanical Engineering
    Study of the Surface Hardening in Pre-stressed Hardening Grinding Combined Machining
    XIU Shi-chao, BAI Bin, ZHANG Xiu-ming, LIU Ming-he
    2015, 36 (1):  86-90.  DOI: 10.12068/j.issn.1005-3026.2015.01.019
    Abstract ( 718 )   HTML   PDF (833KB) ( 792 )  
    Blending the principle of pre-stressed grinding and grinding hardening,an pre-stressed hardening grinding approach was presented. The microstructure, distribution characteristics, thickness and hardness of the grinding hardening layer were studied. The results showed that under the same condition, the microstructure and distribution characteristics of grinding hardening layer in pre-stressed hardening grinding was the same as in grinding hardening and the microstructure was the subcritical quenching. Pre-stressed hardening grinding process showed more restraint effect on grinding heat. The hardening layer thickness and hardness of pre-stressed hardening grinding specimens were slightly below the grinding hardening specimens, but the surface hardness was able to reach the general complete quenching state. The research provides the experiments and principle basis for pre-stressed hardening grinding process development and work-piece surface quality control.
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    Simulation and Experimental Research on Airflow Movement Characteristics of Grinding Zone
    WANG Yu-gang, PEI Shao-yong, XIU Shi-chao
    2015, 36 (1):  91-94.  DOI: 10.12068/j.issn.1005-3026.2015.01.020
    Abstract ( 650 )   HTML   PDF (684KB) ( 801 )  
    Based on the research of airflow movement characteristics in the grinding zone, FLUENT was used to build the finite element model to simulate and calculate pressure distribution and velocity distribution on different working conditions. Combined with the grinding experiment, influence factors of airflow movement on the integrity of the work piece surface were studied and the simulation results were verified. The results indicated that airflow movement in the grinding zone impedes the grinding fluid into the grinding zone. When the injection position of grinding fluid was close to the area with the same direction of wheel rotation linear velocity and airflow velocity, the surface quality of the work piece improved, the utilization rate of grinding fluid and the green degree of grinding raised.
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    Simulation Calculation of Undeformed Chip Thickness in Gear Hobbing
    ZHANG Rong-chuang, WANG Wan-shan, WANG Jun
    2015, 36 (1):  95-99.  DOI: 10.12068/j.issn.1005-3026.2015.01.021
    Abstract ( 715 )   HTML   PDF (990KB) ( 1237 )  
    To solve the instantaneous geometric boundary parameters applied in hobbing force model, a method of simulation calculation of undeformed chip thickness based on the 3D solid modeling was presented. The undeformed chip, which is the intersection between swept volume of hob and workpiece, contains the information of geometric boundary parameters. Boolean operation is used to acquire the undeformed chip. By means of intersection operations on the rake plane of instantaneous hob teeth and the geometric entities of chip, CWE (cutter/workpiece engagement) that includes the information of cutting range constructed by the splines, was obtained. The undeformed chip thickness was extracted from CWE. This method lays a foundation for the precise prediction of dynamic hobbing force.
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    Modeling and Analysis for 3D Chatter Stability of Thin-Walled Parts in Milling Process
    ZHANG Xue-wei, YU Tian-biao, WANG Wan-shan
    2015, 36 (1):  99-103.  DOI: 10.12068/j.issn.1005-3026.2015.01.022
    Abstract ( 887 )   HTML   PDF (677KB) ( 1046 )  
    In view of the thin-walled part with low stiffness, the 3D dynamics model in milling process was built on the machining principle. The chatter stability lobes were predicted using the full-discretization method and validated by the experiments. The results showed that dynamic characteristics of the thin-walled part in milling process determine the dynamics model. There is the nonlinear relation between the limited cutting depth and the spindle speed, and the spindle speed has more effect on the chatter stability than other factors. When the modal mass, relative damping and natural frequency increased, the stability intensifies and the shape of lobes is changed simultaneously. The theoretical model provides the guidance for reasonable selection of cutting parameters and improvement of machined surface quality and machining efficiency.
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    Energy Storage Method by Integrating Elastic Potential Energy and Rotational Kinetic Energy of Cylindrical Spring
    KONG Xiang-wei, HUO Xiao-pei, LIU Gong-yu, MA Ming-xu
    2015, 36 (1):  104-108.  DOI: 10.12068/j.issn.1005-3026.2015.01.023
    Abstract ( 685 )   HTML   PDF (693KB) ( 1152 )  
    By utilizing cylindrical helical springs which were compressed then rotated, a new energy storage method which integrated elastic potential energy and rotational kinetic energy was mentioned and the equipment model was preliminarily built. Energy-density ratios of various common spring materials were contrastively calculated to get the optimal material in energy storage ability. The rotational kinetic energy and elastic potential energy of springs at a range of parameters were contrastively analyzed. The stored energy values of integration energy storage method and corresponding flywheel method were compared.The results show that the integration energy storage method is feasible.
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    Contact Characteristic Analysis of a Compressor Disc Dovetail Structure
    MA Hui, WANG Di, NAI Hai-qiang, TAI Xing-yu
    2015, 36 (1):  109-113.  DOI: 10.12068/j.issn.1005-3026.2015.01.024
    Abstract ( 835 )   HTML   PDF (1590KB) ( 960 )  
    Focusing on the compressor disc dovetail structure, where the compressor disc model consisted of 38 blades, the finite element model of 1/38 of the whole plate was established based on ANSYS software. Considering centrifugal force caused by rotation, the effects of friction coefficient, dovetail installation angle and contact area of interface on contact pressure and contact slip distance were studied. The Lagrange multiplier was applied to calculate the contact responses between dovetail and groove. The results show that the maximum contact pressure and maximum slide distance decrease gradually with the increasing of friction coefficient; the maximum contact pressure increases and the maximum slide distance almost keep constant with the increasing of dovetail installation angle; the maximum contact pressure and maximum slide distance of interface gradually decrease with the increasing of contact area.
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    Multi-agent Cooperation Mechanism Model Based on Dynamic Game
    FAN Si-xia, ZHOU Qi-cai, XIONG Xiao-lei, ZHAO Jiong
    2015, 36 (1):  114-119.  DOI: 10.12068/j.issn.1005-3026.2015.01.025
    Abstract ( 932 )   HTML   PDF (406KB) ( 995 )  
    A multi-agent cooperation mechanism based on dynamic infinite game model was proposed in a multi-agent platform. The infinitely repeated game structure was formed with multi-stage inviting and evaluating actions. Meanwhile, the trust benchmark was proposed to control agent blindness in selection phase and to make sure it could do the rational stage decision. Through the feedback, the multi-agent cooperation mechanism could not only dynamically adjust the income function of each game-agent, but also control cooperation priority. Also, it could achieve a closed-loop control. Additionally, multi-agent were assembled as a basic component unit of intelligent structure. Nine grids experiment was used to validate cooperation mechanism between multi-agent under multiple loading conditions. Moreover, the collaboration status of the agent components unit was also tested based on different trust benchmark. Experiments show that, trust benchmark can effectively adjust the trust level between agents, and promote cooperation in the high frequency agent system.
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    Binary Particle Swarm Optimization Based Process Knowledge Mining for Typical Parts of Satellite
    WANG Lin, ZHANG Yong-jian, ZHONG Shi-sheng, LIU Jin-shan
    2015, 36 (1):  119-123.  DOI: 10.12068/j.issn.1005-3026.2015.01.026
    Abstract ( 636 )   HTML   PDF (528KB) ( 725 )  
    The huge quantity of design of manufacturing process of satellite typical parts and a lot of repeated jobs existed in the process. Many kinds of process knowledge without reused effectively contained in the historical process data. Process knowledge mining algorithm was studied in order to increase efficiency. The problem was described firstly, and the association rule model was built. In order to improve computational efficiency of Apriori algorithm for huge datasets, binary particle swarm optimization(BPSO) was introduced. Meanwhile association rule mining algorithm based on BPSO was designed. Finally, the designed algorithm was used in process knowledge mining for satellite plate. The mining efficiency of process knowledge can be improved effectively by the association rule mining algorithm based on BPSO.
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    Resources & Civil Engineering
    Research on Tannic Acid as Depressant for Galena and Pyrite
    QIU Xian-hui, SUN Chuan-yao, QIU Ting-sheng
    2015, 36 (1):  124-128.  DOI: 10.12068/j.issn.1005-3026.2015.01.027
    Abstract ( 874 )   HTML   PDF (528KB) ( 886 )  
    An organic depressant tannic acid can strongly depress the galena and pyrite while has weekly impact on the flotation of chalcopyrite. Adsorption, UV spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) tests were carried out to investigate the depress mechanism. The results showed that tannic acid adsorbed on the surface of galena and pyrite, which increased the Faraday resistance on mineral surface. Tannic acid can affect the electrochemical oxidation reaction of ethyl xanthate on galena and pyrite surface, hinder part of ethyl xanthate adsorbing on pyrite and galena surface. Since the hydrophilic of tannic acid and it can reduce the formation of hydrophobic product on mineral surfaces, which are the reasons for tannic acid can strongly depress the flotation of galena and pyrite.
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    Characterization and Denitriding Effect of Microwave Modified Zeolite Ecomaterials
    LIN Hai, YANG Su, ZHANG Wen-tong, MA Qi-jun
    2015, 36 (1):  129-133.  DOI: 10.12068/j.issn.1005-3026.2015.01.028
    Abstract ( 650 )   HTML   PDF (802KB) ( 823 )  
    Ecomaterials were modified and prepared by adding different additives on natural zeolite with microwave, and the effect of the matrials on removal of ammonia nitrogen was investigated. The results showed that the removal effect of ammonia nitrogen in sequence under the same modification conditions is microwave-assisted zeolite with sodium acetate, microwave-assisted zeolite with NaCl, microwave-assisted zeolite with SDS, microwave-assisted zeolite with CTMAB, microwave-assisted zeolite and natural zeolite. The aperture, pore volume and BET surface area increased after microwave-assisted zeolite with additives. The results of surface characteristics of zeolite were modificated with microwave or without by SEM and XRD indicated that additives can improve particles surface loose degree of zeolite, and there are more channels, the main diffraction peak intensity weakened,adsorption performance of zeolite improved.
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    Variation Characteristics of Wave Velocity During Rock Failure Process
    ZHANG Peng-hai, YANG Tian-hong, ZHAO Yong-chuan,XIA Dong
    2015, 36 (1):  134-137.  DOI: 10.12068/j.issn.1005-3026.2015.01.029
    Abstract ( 751 )   HTML   PDF (443KB) ( 944 )  
    Under uniaxial multi-level loading condition, the longitudinal wave velocities in different directions from south Fujian diorite were measured.Firstly, based on the experiment results, the changes of wave velocities with stress were analyzed. And then according to the hypothesis of the linear relationship between wave velocity and stress in a very small range of stress, a wave velocity-stress model was built.In the end, using the multi-parameter piecewise fitting, undetermined coefficients in the model were determined. The results showed that the variation of wave velocity paralleled to the loading direction is characterized by an initial instant and nonlinear rise below a critical stress, followed by a more gradual linear increase above this critical stress, and the decrease is not obvious before the failure. Whereas, the variation of wave velocity perpendicular to the loading direction is characterized by a slightly rise below a critical stress, followed by an accelerated decrease above this critical stress, and the decrease is very obvious before the failure. The variation of wave velocities in different directions can be accurately fitted by the wave velocity-stress model, which confirms the applicability of the model.
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    Experimental Study on Similar Material for Simulating Raw Coal
    KANG Xiang-tao, HUANG Gun, DENG Bo-zhi, HAN Pei-bo
    2015, 36 (1):  138-142.  DOI: 10.12068/j.issn.1005-3026.2015.01.030
    Abstract ( 683 )   HTML   PDF (843KB) ( 872 )  
    Coal powder and sand are both used as two kinds of aggregates, and both gypsum and cement are used as cementing agent in the similar material preparation of raw coal. Through the single factor analysis, the influence on the strength of similar material under different composition proportions of coal powder, gypsum, cement and sand was studied during the experiments. The results indicated that the similar material of coal powder as aggregate shows a negative linear correlation between the strength and coal powder consumption dosage, meanwhile, the properties of similar material is easy to be controlled. While the similar material that uses sand as the aggregate shows a non-linear relationship, and the properties of similar material is difficult to be controlled. Therefore, the coal powder is more suitable than sand as the aggregate of similar material of raw coal.The results provide good references for similar material design of raw coal.
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    Form Finding and Internal Force Calculation of the Cable in Ornamental Suspension Bridge
    HUANG Wen, ZHENG Ming-wan, XU Feng, ZHOU Jun-jie
    2015, 36 (1):  143-147.  DOI: 10.12068/j.issn.1005-3026.2015.01.031
    Abstract ( 845 )   HTML   PDF (487KB) ( 929 )  
    As an inseparable component, the decorative cable of ornamental suspension bridge does not carry loads with the main structure. The main cable and hanger rods should have certain internal force that matches with the main bridge so as to keep their line-shapes. An approach was proposed for such bridge to calculate the blanking length and tensile force of the cable and rods. Firstly, a model for the main cable was built with hanger rods simplified as vertical constraints. Secondly, the tensile force of main cable in each section and the constraining force of rods were calculated. Finally, the blanking length of each member can be obtained. With a project in Xinjiang, a partial FE(finite element) model of main cable is established by the MIDAS/Civil to calculate the theoretical tensile forces and blanking lengths of the cable and rods, and check its dynamic characteristics. The as-built bridge meets all requirements.
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    Management Science
    A Method for Risky Multi-attribute Decision Making with Multiple Reference Points
    LIU Yun-zhi, FAN Zhi-ping
    2015, 36 (1):  148-152.  DOI: 10.12068/j.issn.1005-3026.2015.01.032
    Abstract ( 592 )   HTML   PDF (341KB) ( 708 )  
    A method based on cumulative prospect theory was proposed to solve risky multi-attribute decision making problems with multiple reference points. First, in light of cumulative prospect theory, the prospect value and decision weight of each alternative with regard to each person were calculated in different natural states, and the comprehensive cumulative prospect value of each alternative with regard to each person was obtained accordingly. Then, the expected degree of consistency for each person′s decision information and overall decision information was calculated, and each person′s weight was obtained.On this basis, the overall cumulative prospect value of each alternative was calculated, and the alternative ranking was determined. Finally, a numerical example was given to illustrate the applicability of the proposed method.
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