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15 October 2014, Volume 35 Issue 10 Previous Issue    Next Issue
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Information & Control

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Hybrid Model Based on ICALSSVM for Copper Extraction YU Liang， MAO Zhizhong， JIA Runda 2014, 35 (10):  1369-1372.  DOI: 10.12068/j.issn.1005-3026.2014.10.001 Abstract ( 630 )   HTML   PDF (426KB) ( 576 )   Due to the mass concentration of component was hard to measure online in hydrometallurgy extraction process，so a data modeling method was proposed by combining independent component analysis with least squares support vector machine(ICALSSVM)， which was used to establish the forecasting model of copper extraction.First， the independent component analysis was used to pretreat the field data. Then， the least squares support vector machine was used to established distribution ratio model which was used to identify the unknown parameter and enhance the accuracy of model. The simulation results showed that the models were practical and efficient， which could provide a theoretical basis for the control. References | Related Articles | Metrics

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Modeling and Simulating Joint Operation of PEV and Microgrid in Smart Grid HAN Peng， WANG Jinkuan， HAN Yinghua， LI Yan 2014, 35 (10):  1373-1377.  DOI: 10.12068/j.issn.1005-3026.2014.10.002 Abstract ( 798 )   HTML   PDF (1213KB) ( 905 )   A model of the microgrid operations with plugin electric vehicles (PEVs) in the smart grid was proposed using the combined modeling method. The models of microgrid load， PEV， generation and storage devices were setup on the basis of the multiagent modeling method， the batterychanging station model on the basis of the discrete event modeling method， and the microgrid bus power model on the basis of the system dynamics modeling method. The results demonstrated that the access of the PEVs increases the microgrid peaktime load in the daytime as well as the load in the night， which causes the increase of the peak load and peaktoaverageratio (PAR)， so the electricity storage devices should be added to improve the ability to absorb the depleted electricity from the renewable energy sources and to supply the PEV charging service. Besides， with the sufficient charging service supporting， the PEVs have fewer demands on the batterychanging service. The proposed models can well reflect the PEV and microgrid operation procedure， and shall be of great importance for the microgrid safety， reliability and efficiency. References | Related Articles | Metrics

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DVHop Localization Algorithm with Collinearity in Wireless Sensor Network ZHANG Yunzhou， XIANG Shu， FU Wenyan， JIA Zixi 2014, 35 (10):  1378-1381.  DOI: 10.12068/j.issn.1005-3026.2014.10.003 Abstract ( 541 )   HTML   PDF (578KB) ( 501 )   When anchor nodes form collinearity， which means that the anchor nodes locate in almost the same straight line， negative effect will be caused upon positioning accuracy， and therefore the precision will be declined. Considering the collinearity features， a DVHop strategy was proposed for the largescale rangefree localization in wireless sensor network. Voronoi diagram was used to divide the network into several regions. Then anchor nodes were selected and purified by collinearity. According to the hop limit threshold， the information of anchor nodes in each region and conform collinearity condition were utilized to localize the unknown node. Simulation results showed that the proposed strategy， compared with the traditional DVHop and collinearity algorithm， could effectively decrease the computational complexity， improve the node positioning accuracy and reduce the localization error. For the asymmetrical networks， the strategy could achieve higher precision node positioning and be suitable for complex environment. References | Related Articles | Metrics

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Optimal FractionalOrder PIλDμ Network Delay Controller PAN Feng， LIU Lu， XUE Dingyu 2014, 35 (10):  1382-1385.  DOI: 10.12068/j.issn.1005-3026.2014.10.004 Abstract ( 717 )   HTML   PDF (477KB) ( 598 )   The fractional control theory was used to study delay of network control system， and an optimal fractionalorder PIλDμ network delay controller was designed. The control effects of the optimal PIλDμ and optimal PID controller with fixed and random network delay were compared and simulated. The results showed that both fractionalorder and integerorder controllers could achieve satisfactory results for the network control system of integerorder， but the overshoot， rising time and accommodation time of step response of fractionalorder PIλDμ controller were smaller than those of the integerorder one， and it was proved that optimal fractionalorder controller possessed more capacity to deal with network delay. References | Related Articles | Metrics

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FaultTolerant Synchronization Control Based on SampledData for Chaotic System REN Tao， HUANG Jin， YU Hai， WANG Jingyang 2014, 35 (10):  1386-1389.  DOI: 10.12068/j.issn.1005-3026.2014.10.005 Abstract ( 642 )   HTML   PDF (437KB) ( 601 )   For the chaotic systems with failures， the samplebased chaos systems were converted into discretetime system by using the Euler approximate discretization approach. A mathematic model was established for a class of common faults， with the observer designed. The design method of the faulttolerant synchronization controller was given to achieve the synchronization of two chaotic systems， with the sufficient condition given for asymptotic stability of the error system. The controller gain was solved by LMI of Matlab. Synchronization of the two Chua’s circuits was realized by simulation. Compared with other algorithm， the effectiveness and the faulttolerant performance of the proposed method were illustrated. References | Related Articles | Metrics

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WiFi Fingerprint Localization Algorithm Based on Sliding Window Combined with Longest Common Subsequence ZHANG Mingyang， CHEN Jian， WEN Yingyou， ZHAO Hong 2014, 35 (10):  1390-1393.  DOI: 10.12068/j.issn.1005-3026.2014.10.006 Abstract ( 726 )   HTML   PDF (625KB) ( 788 )   To reduce the negative effect in the WiFi fingerprint localization algorithm caused by the fluctuation of the received signal strength (RSS)， a WiFi fingerprint localization algorithm based on sliding window combined with the longest common subsequence was proposed. First， the time sequence RSS fingerprints were converted to the sliding window data model to increase the fingerprint characteristic information and improve the matching accuracy. And then， the requesting location data and the longest common subsequence were calculated to get the similarity of sampling points， which could solve the problem caused by the window scaling or the individual sampling point without signal in the sliding window， thereby the localization accuracy and robustness were improved. The results showed that the proposed localization algorithm was superior to the instantaneous fingerprints localization algorithm. References | Related Articles | Metrics

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Construction Method Based on TimeSpace Influence Domain for Earthquake Network HE Xuan， ZHAO Hai， CAI Wei， ZHANG Ya 2014, 35 (10):  1395-1399.  DOI: 10.12068/j.issn.1005-3026.2014.10.007 Abstract ( 653 )   HTML   PDF (503KB) ( 666 )   A construction method based on timespace influence domain for earthquake network was put forward for the seismic complexity in timespace. The range of direct effect was determined according to the magnitude of earthquake. The results showed that the proposed earthquake network， in which the power exponent was between 1 and 2， was scalefree in different time spans. And there was a positive correlation between indegree and outdegree of nodes. The average clustering coefficient increased quickly after main shocks， then decreased gradually as time went on and finally stayed stationary. The earthquake networks based on timespace influence domain， which presented certain statistical laws， could help scientists to analyze the internal mechanism of seismic system. References | Related Articles | Metrics

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DFT Channel Estimation Based on Improved Threshold in OFDM System JI Ce， TIAN Chuntang， WANG Lijuan 2014, 35 (10):  1400-1403.  DOI: 10.12068/j.issn.1005-3026.2014.10.008 Abstract ( 563 )   HTML   PDF (525KB) ( 624 )   Conventional DFTbased channel estimations algorithm cannot suppress noise inside the CP. To solve the problem， a new DFT channel estimation algorithm， which took the median of the energy of all the time domain noise samples point as threshold， was proposed by analyzing shortcomings and deficiencies of these algorithms with many different thresholds to suppress noise. Simulation results showed that the proposed algorithms could effectively solve the problem that the significant channel samples were filtered under big impulse noise. What’s more， the noise inside the CP was suppressed effectively， and the bit error rate and mean square error were further decreased， resulting in the improvement of the channel estimation accuracy. References | Related Articles | Metrics

Materials & Metallurgy

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Effect of Annealing Temperature on FeTiPType Precipitate in PAdded IF High Strength Steel ZHANG Jiecen， DI Hongshuang， JIANG Guangwei， CAO Yu 2014, 35 (10):  1404-1407.  DOI: 10.12068/j.issn.1005-3026.2014.10.009 Abstract ( 599 )   HTML   PDF (1020KB) ( 726 )   A systematic and detailed characterization of FeTiPtype precipitate， as a function of annealing temperature， was studied for a batchannealed Padded interstitial free high strength steel (IFHS). The results showed that a small number of FeTiP is observed at 650 ℃ and it increases dramatically with the increase of annealing temperature. FeTiP distributes within grains and at grain boundaries， but the size of intragranular FeTiP is found to be significantly smaller than that at grain boundary. FeTiP is totally dissolved and can not be detected at 800 ℃. The absence of FeTiP eliminates its inhibition effect on recrystallization and a high intensity {111} recrystallization texture is obtained， which improves the formability of IFHS. FeTiP is orthorhombic structure， and the enrichment of Nb in FeTiP precipitates does not alter the crystal structure of FeTiP. References | Related Articles | Metrics

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Effect of Continuous Annealing Process on Microstructure and Properties of B250P Steel JIANG Guangwei， WANG Chunliu， CAO Yu， DI Hongshuang 2014, 35 (10):  1408-1411.  DOI: 10.12068/j.issn.1005-3026.2014.10.010 Abstract ( 609 )   HTML   PDF (703KB) ( 629 )   The continuous annealing process of B250P steel was simulated， and the effects of continuous annealing process parameters (heating rate， annealing temperature， holding time and cooling rate) on the microstructure and properties of B250P steel were investigated by using optical microscopy， transmission electron microscopy and tensile test. The results showed that the grain size of B250P steel increases with heating rate， annealing temperature and cooling rate. While the grain size firstly increases and then decreases with increasing the holding time. The dominant precipitates during the annealing process are nanoscale NbC and TiC， which can pin the dislocations and high angle boundaries as well as refine the grains. The rvalue of B250P steel increases with increasing the heating rate and decreases with increasing the cooling rate. The rvalue increases and then decreases with increasing annealing temperature and holding time. References | Related Articles | Metrics

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Ultrarapid Heating Annealing Process of BHIF Steel XU Dechao， LI Jun， MENG Qingge， LIU Yandong 2014, 35 (10):  1412-1416.  DOI: 10.12068/j.issn.1005-3026.2014.10.011 Abstract ( 709 )   HTML   PDF (849KB) ( 775 )   The recrystallization texture evolution and mechanical properties of coldrolled BH (bakehardening)IF (interstitial free) steel were investigated under different annealing parameters. The results indicated that the tensile strength and the elongation increase with increasing heating rate. In the fully recrystallized condition， the ultrarapid heating gives rise to substantially refined structures with an unconspicuous reduction of average ferrite grain size. Under the condition of ultrarapid heating rate， XRD texture analysis showed that the difference in γ texture components and orientation intensity of BHIF steel get narrow and the γ texture becomes more homogenous. The strong γ texture is obtained simultaneously for both rapid and normal heating rate. The intensity of {111} texture increases with increasing holding time， so the r value increases. Under the ultrarapid heating rate， the r0 value decreases and the r90 increases， while the rm (average) remains almost unchanged. References | Related Articles | Metrics

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Temperature Distribution of 7050 Alloy During Homogenization with Current JIA Pinfeng， HE Lizi， ZHANG Haitao， CUI Jianzhong 2014, 35 (10):  1417-1421.  DOI: 10.12068/j.issn.1005-3026.2014.10.012 Abstract ( 598 )   HTML   PDF (868KB) ( 521 )   Influences of current， fan frequency， cooling water， auxiliary heating on the temperature distribution of 7050 alloy were investigated. When current is applied alone， the surface temperature and center temperature of sample are different significantly. When the current is 1 500 A， the center temperature reaches 402 ℃. The deviation between the center and surface temperatures is 79 ℃ when blowing air is used during the current heating process， and becomes less than ± 5 ℃ when the auxiliary heating is used. The mathematical model established by ANSYS was employed to predict the temperature field of the sample with size of 100 mm×200 mm×2000 mm. When the current is 16 000 A， the center temperature is 324 ℃， and the deviation between the center and surface temperatures is 1 ℃. The results provide the basis for designing the auxiliary heater. The dissolution of the residual grain boundary phases was accelerated when applying the current of 1000A during homogenization. References | Related Articles | Metrics

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Effect of Multipass Friction Stir Processing on Microstructures and Mechanical Properties of 5083O Aluminum Alloy CHEN Yu， LI Xiaohua， FU Mingjie， DING Hua 2014, 35 (10):  1422-1426.  DOI: 10.12068/j.issn.1005-3026.2014.10.013 Abstract ( 634 )   HTML   PDF (1585KB) ( 736 )   Multipass friction stir processing (3pass FSP with 100% overlap) was conducted under different diameters of shoulders， rotation speeds and travel speeds to investigate the effect of processing parameters on the microstructures and the mechanical properties of 5083O aluminum alloy. The results showed that the fine and dynamically recrystallized grains are observed in the FSP zone. With increasing the number of passes， the grain size and the tunnel defects decrease， the second phase particles are refined and distributed uniformity， the ultimate tensile strength reaches up to 360 MPa， and the elongation is higher than that of the base metal. The effect of the 2ndpass on the microstructures and mechanical properties is most obvious. References | Related Articles | Metrics

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Simulation on Effect of Electric Induction Reheating on Microstructure of Hot Rolled Low Alloy Steel CHEN Zejun， LI Hongtu， ZHANG Jing， HUANG Guangjie 2014, 35 (10):  1427-1431.  DOI: 10.12068/j.issn.1005-3026.2014.10.014 Abstract ( 479 )   HTML   PDF (1054KB) ( 527 )   The thermal simulator Gleeble 1500D was used to investigate the microstructure evolution of hot rolled low alloy steel during cooling and reheating. The effect of reheating process on microstructure was studied in the conditions of different cooling temperature， quenching and normalizing heat treatments， respectively. The results showed that the effect of the reheating process after rolling on the quenched steel sample is more remarkable than on normalized sample. When the deformed steel is cooled to twophase region， the reheating process improves the uniformity of temperature distribution， affects the phase transformation of ferrite and precipitation of carbonitrides， prompts the growth of grains， and effectively improves and controls the microstructure and mechanical properties of the quenched steels. References | Related Articles | Metrics

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New Method for Measuring Additives in TinPlating Solution LI Binghu， LIU Changsheng， TANG Gangfeng， JIA Yu 2014, 35 (10):  1432-1436.  DOI: 10.12068/j.issn.1005-3026.2014.10.015 Abstract ( 717 )   HTML   PDF (468KB) ( 1005 )   A high performance liquid chromatographic (HPLC) method was established for the analysis of αnaphthol polyoxyethylene ether and αnaphtha sulfonate polyoxyethylene ether in tinplating solution. Plating solution was first treated with sodium phosphate dibasic to detach Sn2+ and Fe2+. The extracts were then cleanedup by high performance liquid chromatography with an ultraviolet detector on a Agilent ZORBAX Eclipse XDBC18 column by UV at 215 nm， using 20 mmol/L sodium phosphatemethanol (48∶52) as a mobile phase. The average recoveries of this method were in the range of 966%~989%. The deviation of HPLC was less than 005 g/L.The proposed method was fast， accurate， sensitive， reproducible， and it could meet the requirement of tinplating process. References | Related Articles | Metrics

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Effect of Ambient Temperature on Characteristics of Jets from Oxygen Lance in BOF Steelmaking LI Mingming， LI Lin， LI Qiang， ZOU Zongshu 2014, 35 (10):  1437-1441.  DOI: 10.12068/j.issn.1005-3026.2014.10.016 Abstract ( 593 )   HTML   PDF (716KB) ( 827 )   Combining the standard k~ω model with the Reynolds averaged NavierStokes (RANS) equations， a compressible， nonisothermal and threedimensional CFD model was developed for the multiple nozzle supersonic jets in topblown steelmaking convertor， and the validity of the model was verified by experiment. The effect of temperature field on molecule viscosity of fluid was considered， and the dynamic properties of jets were studied in different temperature fields. The results showed that ambient temperature makes a great influence on jets velocity， temperature and density distributions. With the increase of ambient temperature， the jets density decreases，their velocity attenuation is slower， velocity is higher and radial expanding of jets is much easier. Jet is more likely to coalescence in lower ambient temperature. As jets travel in axial direction， the effect of ambient temperature on jets dynamic pressure tends to negligible. That is to say， the effect of the ambient temperature on the impacting force of jets on the bath is weakened， but impinging area increases with the increase of ambient temperature. References | Related Articles | Metrics

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Inclusions Behavior and Removal in Tundish with Induction Heating WANG Qiang， SHI Yueming， LI Yiming， LI Baokuan 2014, 35 (10):  1442-1446.  DOI: 10.12068/j.issn.1005-3026.2014.10.017 Abstract ( 853 )   HTML   PDF (2053KB) ( 721 )   A threedimensional transient mathematical model was developed to investigate the inclusions movement and removal in the continuous casting tundish with channeltype induction heating. According to the force balance， the inclusion movement behavior was investigated by EulerLagrange approach. A mathematical model was established for the collision and coalescence of inclusions in tundish with different induction heating powers， and the effect of collision and coalescence of inclusions on the removal ratio was investigated. The results showed that the inclusions will be subjected to an electromagnetic pressure force when molten steel flows pass the channel and move to the channel wall， which is beneficial to the removal of inclusions. Collision and coalescence improve remarkably the removal ratio of small inclusions. The induction heating is beneficial to the inclusion removal， especially for the small inclusions. References | Related Articles | Metrics

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FirstPrinciples of Mechanical and Thermodynamic Properties for ZrN TAN Xin， JIA Yichao， LIU Xuejie 2014, 35 (10):  1447-1451.  DOI: 10.12068/j.issn.1005-3026.2014.10.018 Abstract ( 602 )   HTML   PDF (746KB) ( 1012 )   The equilibrium properties， elastic and thermodynamic properties of fccZrN under different pressures were studied by using the plane wave pseudo potential method based on density functional theory (DFT). It was inferred that the structural phase transition of ZrN from fcc structure to bcc structure occurs between 208 to 220GPa by analyzing the relations of enthalpy and elastic property with pressure. The anisotropy of mechanical properties under different pressure was further studied to get the relation between the pressure and mechanical properties of ZrN. The thermodynamic properties of fccZrN were calculated. The results showed that the mechanical isotropy decreases significantly with increasing pressure. The heat capacity decreases with increasing pressure at certain temperature. The Debye temperature increases with pressure. The temperature plays the main role in the low pressure zone， and the pressure in the highpressure zone. References | Related Articles | Metrics

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Numerical Simulation of Carbonation Reactor for Calcified Residues ZHANG Zimu， LIU Yan， ZHANG Jun， WANG Ying 2014, 35 (10):  1452-1455.  DOI: 10.12068/j.issn.1005-3026.2014.10.019 Abstract ( 654 )   HTML   PDF (1000KB) ( 529 )   Aiming at the problem of the low utilization of lowgrade bauxite in industry and that of the highalkali and highaluminum contents in red mud， a new method of calcificationcarbonation was proposed to process lowgrade bauxite and red mud. A venturi carbonation reactor for calcified residues was designed， and the dynamic characteristics of gasliquidsolid threephase flow in the reactor were simulated by using ANSYS130/Fluent. The effect of operation parameters such as superficial gas velocity on velocity field and gas holdup in the reactor was simulated and investigated. It shows that high gas velocity benefits gasliquid mass transfer and reaction， but the gas holdup should not be too large. The simulation results of average gas holdup agree well with the measured ones， thus the effectiveness of the method is verified. The results have a certain reference value for the design and application of venturi carbonation reactor. References | Related Articles | Metrics

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Specific Surface Area and Pore Characteristics of Aluminum Hydroxide Prepared from HighAlumina Fly Ash ZHANG Tingan， ZHENG Chaozhen， LYU Guozhi， SUN Junmin 2014, 35 (10):  1456-1459.  DOI: 10.12068/j.issn.1005-3026.2014.10.020 Abstract ( 689 )   HTML   PDF (444KB) ( 803 )   Using sintered highalumina fly ash clinker as raw material， high white aluminum hydroxide was obtained after dissolution， deep desilication and decomposition (carbonation decomposition or seed precipitation) process. Lowtemperature nitrogen adsorption method was adopted to analyze the specific surface area and pore distribution of aluminum hydroxide. The results showed that the aluminum hydroxide adsorption isotherm curve belongs to type III. Aluminum hydroxide pores most belong to micropores， and there still are some mesopores and macropores. The BET specific surface area and average pore diameter of carbonation aluminum hydroxide are much greater than those of seedprecipitation aluminum hydroxide. Driven by the strong action of CO2， aluminum hydroxide precipitates and condenses fiercely in carbonation decomposition， so the crystal structure of aluminum hydroxide is loose and intergranular pores are big. In seed precipitation， the growth of crystal makes the crystal coarsen， the structure is compact and intergranular pores are small. References | Related Articles | Metrics

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Pellets Preparation by Direct Briquetting for Silicothermic Magnesium Production WEN Ming， ZHANG Tingan， DOU Zhihe， ZHOU Lian 2014, 35 (10):  1460-1463.  DOI: 10.12068/j.issn.1005-3026.2014.10.021 Abstract ( 530 )   HTML   PDF (460KB) ( 596 )   During the preparation process of the raw material in magnesium production with silicothermic method， about 5% fines are lost in the dolomite calcination process. In order to solve this problem， a new technology was proposed that dolomite is made into pellets first， and then calcined to prepare pellets with high reactivity and stability. The burning loss of dolomite， the ignition loss of the calcined dolomite and the hydration activity of pellets were investigated after calcination. The results indicated that calcined dolomite with good properties can be prepared via direct briquetting technology， and the calcination time is shortened effectively. When calcination time reaches 1h， the burning loss of briquetted dolomite can reach 45%， the ignition loss of calcined dolomite can reach 189%， the hydration activity can reach 35%. The moisture absorption of pellets in this process is much less than that in conventional calcination process. References | Related Articles | Metrics

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Occurrence of Lead and Barium in Roasted HighLead Copper Anode Slime LI Xuejiao， YANG Hongying， GUO Jun， LYU Yang 2014, 35 (10):  1464-1467.  DOI: 10.12068/j.issn.1005-3026.2014.10.022 Abstract ( 624 )   HTML   PDF (420KB) ( 583 )   The mineralogical characterization of lead and barium in roasted highlead copper anode slime were studied by a variety of mineralogical techniques. The results showed that limited solid solution of (Pb， Ba)SO4 forms by PbSO4 coming into BaSO4. Meanwhile， (Pb， Ba) is partially replaced by Ag to form (Pb， Ba， Ag)SO4 and sometimes S is partially replaced by Sb to form (Pb， Ba)S(Sb)O4. The structure formed by base metals is complicated as CuO and (Pb，Ba)SO4 are always wrapped by each other. Tiny AuAg alloy particles are always wrapped by (Pb， Ba)SO4 and sometimes parallel eutectic system is formed by (Pb， Ba)SO4 and relatively larger particle of AuAg alloy. References | Related Articles | Metrics

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Desulfurization of SiMn Alloy with High Sulfur ZHU Zizong， FAN Jinhuan， LI Qin， XIE Zewei 2014, 35 (10):  1468-1471.  DOI: 10.12068/j.issn.1005-3026.2014.10.023 Abstract ( 602 )   HTML   PDF (738KB) ( 605 )   The effects of MgO， CaO， BaO in CaOBaOMgOSiO2CaF2 slag on the desulfurization of SiMn alloy with high sulfur were studied in a silicon molybdenum furnace， and with XRD and chemical analyses. The results showed that the desulfurization ability rises first and then falls with increasing m(BaO)∶m(CaO) ratio. When the mass fractions of MgO and CaF2 are 8 % and 10% respectively， and m(BaO)∶m(CaO) is 0914 3， the desulfurization efficiency reaches to 944%. When the mass fractions of MgO and CaF2 are 12 % and 14 % respectively， and m(BaO)∶m(CaO) is 0787 9， the desulfurization efficiency reaches to 954%. Meanwhile，when the mass fractions of CaO and BaO are 35% and 32 % separately， the desulfurization ability rises first and then falls with increasing the mass fraction of MgO， and the desulfurization effect is the best when the mass fraction of MgO is 8 %. References | Related Articles | Metrics

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Factors Influencing Interfacial Separation of Ferronickel from Slag in Semimelting Reduction of Nickel Laterite LYU Xuewei， YUAN Qiugang， LIU Mei， BAI Chenguang 2014, 35 (10):  1473-1477.  DOI: 10.12068/j.issn.1005-3026.2014.10.024 Abstract ( 627 )   HTML   PDF (1311KB) ( 788 )   The separation of metal and slag and tapping of slag are the key issues for the industrialization of the semimelting reduction process of nickel laterite ores. To solve the problem， the effect rules of CaO and system temperature on the behavior of metalslag separation were experimentally investigated， as well as the interface spreading behavior of slag on different refractory materials. The results showed that， without CaO addition， the liquid metal agglomerates well at 1440 ℃， and the metal mass fraction of “concentrate” from magnetic separation is 61%. With increasing the mass fraction of CaO， the liquid metal gets easier to agglomerate and grow up， and the mass fraction of metal is improved significantly， reaching up to 937% with 15%CaO at 1400 ℃. The wettability of slag to Al2O3 refractory is good， but it is difficult to spread on graphite. In the experimental range， increasing the basicity of slag deteriorates its wettability. References | Related Articles | Metrics

Resources & Civil Engineering

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Effect of Sodium 2，3dihydroxypropyl Dithiocarbonate on Floatability of CuPb Sulfide Ores PIAO Zhengjie， WEI Dezhou， LIU Zhilin 2014, 35 (10):  1478-1481.  DOI: 10.12068/j.issn.1005-3026.2014.10.025 Abstract ( 706 )   HTML   PDF (525KB) ( 625 )   Sodium 2， 3dihydroxypropyl dithiocarbonate (SGX)， a small molecule organic depressant， was used to investigate on the selective depression of galena from chalcopyrite in the flotation tests by diethyl dithiocarbamate， and zeta potential and infrared spectrum measurements were performed to study the interaction mechanism between SGX and minerals. The flotation tests of single minerals showed that SGX has slight activation on chalcopyrite and strong depression on galena in the whole pH range. With the increasing of mass concentration of SGX， the recovery of galena decreases rapidly， while that of chalcopyrite has a slight increase. The satisfied separation results of artificially mixed samples showed that the mass fraction and recovery of copper are 2966% and 8523% at 6 of pH value with 19 g/L SGX， respectively. Zeta potential and infrared spectrum measurements indicated that SGX has more strongly adsorption capacity on galena than chalcopyrite. References | Related Articles | Metrics

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Membrane Filtration Characteristics in ElectroCoagulation Membrane Bioreactor LI Liang， ZHANG Xueyu， QIAN Guangsheng， HU Xiaomin 2014, 35 (10):  1482-1486.  DOI: 10.12068/j.issn.1005-3026.2014.10.026 Abstract ( 638 )   HTML   PDF (836KB) ( 678 )   As simulated dyeing and printing wastewater was taken as the research object， the membrane fouling and sludge mixed liquor properties in ECMBR and conventional MBR pilot systems were investigated. The results showed embrane filtration resistance were dominated by cake resistance， the cake resistance makes up 99% and 9334% of total resistance in MBR and ECMBR， respectively. However， the total resistance in ECMBR is 1/4 in MBR， which means electrocoagulation can effectively reduce cake resistance. Bigger particle size diameter(PSD)， smaller absolute value of Zeta potential， lower concentration of extracellular polymeric substances (EPS) and soluble microbial products (SMP) and higher relative hydrophobic (RH) of sludge are found in ECMBR than those in MBR by comparing the difference of sludge mixed liquor properties. The electrocoagulation is effective to improve the filtration performance of membrane bioreactor， increase membrane flux and decrease the membrane resistance by changing the sludge mixed liquor properties. References | Related Articles | Metrics

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Formation Mechanism of HighFluorine Groundwater in West Area of Songliao MA Shimin， XU Xinyang， CHEN Xi， GUO Xiaodong 2014, 35 (10):  1487-1491.  DOI: 10.12068/j.issn.1005-3026.2014.10.027 Abstract ( 536 )   HTML   PDF (1185KB) ( 561 )   The enrichment of fluoride in groundwater is a very complicated hydrogeochemical process， and has a close relation with geological environment. To find out the distribution and formation conditions of highfluorine groundwater， systematic analysis work from several angles， such as strata， weather， terrain and landform，hydrogeology and hydrochemistry， etc. ， was made by survey of environmental geology and test of water sample. The main distribution areas of highfluorine groundwater in this area were proved up. The formation mechanism of highfluorine groundwater was analyzed according to a large number of the groundwater chemical analysis data. The results showed that one of the most important reasons caused the formation of high fluoride water is fluorine ions in rock and soil through eluviation into groundwater. The results provide a scientific basis for the prevention of drinking water type fluorosis and the occurrence of endemic fluorosis. References | Related Articles | Metrics

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Improving Optimization Algorithm of Production Scheduling for OpenPit Metal Mine GU Xiaowei， XU Xiaochuan， WANG Qing， LIU Jianping 2014, 35 (10):  1492-1495.  DOI: 10.12068/j.issn.1005-3026.2014.10.028 Abstract ( 568 )   HTML   PDF (426KB) ( 673 )   In optimizing production scheduling of openpit mine， the effect of overlap among cones on its average grade was usually ignored， in oder to deal with this shortcoming， an improved cone elimination algorithm was proposed. In the process of cone elimination， the spatial search logic was redefined， the average grade of cones influenced by the lowest grade cone and rearranged cones in the cone array were recalculated. A dynamic sequence model was established by taking the geological optimum pushbacks generated by new algorithm as state variable， all feasible paths were evaluated， and the path whose NPV is the biggest was taken as the optimal exploitation scheme. The application example showed that under the same conditions of technology and economy， the improved algorithm is superior to the initial algorithm in the production stability and NPV， where the NPV increases by 105%. References | Related Articles | Metrics

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Ventilation Dust Removal System in High InclinationAngle Fully Mechanized Caving Face Based on FLUENT YAO Xiwen， LU Guangli， XU Kaili， WANG Yantong 2014, 35 (10):  1497-1501.  DOI: 10.12068/j.issn.1005-3026.2014.10.029 Abstract ( 663 )   HTML   PDF (1489KB) ( 708 )   The ventilation system of high inclinationangle fully mechanized caving face is complicated， and it is difficult to determine the optimal dust exhausting wind speed because of high inclinationangle and variable wind. In view of this fact， based on gassolid flow theory， a numerical simulation mode for high inclinationangle fully mechanized caving face was established. Via applying FLUENT software， the wind flow regularities and dust distribution， together with the reducing dust mechanism and the optimal dust exhausting wind speed， were investigated under different ventilation modes. The results showed that the dust mass concentration of ascentional ventilation in footway space ranges from 1200 to 1600mg/m3， the dust mass concentration of descentional ventilation ranges from 460 to 600mg/m3. The descentional ventilation is more applicable to the high inclinationangle fully mechanized caving face. The optimal dust exhausting wind speed is 25~28m/s， and the wind speed should be controlled below 30m/s. Experiment was performed in the working face， and the experimental results agree with the simulation results， thus verifying the reliability and accuracy of the numerical results. The research results can be used as theoretical guide for developing specifical prevention measures in high inclinationangle fully mechanized caving face. References | Related Articles | Metrics

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Extenics Evaluation of Engineering Geological Zoning of Foundation Soil in Tianjin Binhai New Area SONG Shengyuan， WANG Qing， SUN Tao， BAO Shuochao 2014, 35 (10):  1502-1506.  DOI: 10.12068/j.issn.1005-3026.2014.10.030 Abstract ( 606 )   HTML   PDF (544KB) ( 651 )   Based on the extenics， a prediction and evaluation model for soil settlement was established when the soft clay depth，thickness， void ratio， liquidity index and modulus of compression are regarded as evaluating indexes. The advantages of this model is that the evaluation results were expressed by the quantitative data and there is no limit for the number and variety of evaluation factors. Hence， this model can not only be applied to the soil of different engineering geological conditions， but also maximize the utilization of engineering geological exploration. The new method was applied to the sedimentation evaluation regarding foundation soil in Tianjin Binhai New Area. The extenics evaluation results are consistent with the insitu measurements. Furthermore， soft soil thickness and compression modulus are the main factors influencing the sedimentation of study area. Finally， the obtained engineering geological zoning is scientific and reasonable according to the settlement level. References | Related Articles | Metrics

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Numerical Simulation on Effects of Vertical Tunnel Excavation on Underground Pipeline in Sand WANG Zhengxing， MIAO Linchang， SHI Wenbo 2014, 35 (10):  1507-1511.  DOI: 10.12068/j.issn.1005-3026.2014.10.031 Abstract ( 537 )   HTML   PDF (1708KB) ( 676 )   In order to investigate the deformation of pipeline during tunnel excavation， the relations between the macroscopic and microscopic parameters of pipelines were formed based on laboratory deflection test and PFC programming. Based on the PFC2D， the numerical model of the tunnelsoilunderground pipeline was established for simulating the deformation of pipelines during tunneling in sand， and the effects of ground loss and tunnelpipeline space were examined. The numerical results showed that the behavior of pipelines is negative downdrag in the middle and positive downdrag at 35 times the diameter of tunnel from the middle of pipelines， which are greater under the increase of ground loss and decrease of tunnelpipeline space. With increasing ground loss and decreasing tunnelpipeline space， the additional load on the top of pipeline increases and the vertical earth pressure decreases quickly at the bottom of the pipeline， which trends to reach a final value. The ratio of ip/i as the width coefficient is proportional to the ground loss， and inversely proportional to the tunnelpipeline space， where the maximum value of 24 can be reached. References | Related Articles | Metrics

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Trajectory Control of 3TPS Hybrid Robot Based on Clipper Controller SHI Jiashun， WANG Kai， ZHU Lida， WANG Wanshan 2014, 35 (10):  1512-1515.  DOI: 10.12068/j.issn.1005-3026.2014.10.032 Abstract ( 607 )   HTML   PDF (480KB) ( 581 )   An open CNC system of 3TPS hybrid robot based on the Clipper controller was proposed according to the characteristics of motion performance and structure of 3TPS hybrid robot. To solve the key questions of the angle coupling swing head with rotary table and variant of tool edit position by rotary table motion， a mathematical model of inverse kinematics position was established for the hybrid robot. The model was transformed to the position motion control algorithm based on the hardware platform， and the experiment of spiral trajectory was conducted on the sphere surface. The results showed that the control system can satisfy in control command of robot， the kinematics model and control algorithm are accurate and reasonable. References | Related Articles | Metrics

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Reliability Assurance of Highly Precise Rolling Bearing Clearance LI Haochuan， SUN Zhili， YAN Ming 2014, 35 (10):  1516-1520.  DOI: 10.12068/j.issn.1005-3026.2014.10.033 Abstract ( 505 )   HTML   PDF (551KB) ( 674 )   A reliabilitybased design for rolling bearing clearance was carried out. The effects of random factors like interference fitting and speed on clearance were obtained based on the theory of elasticity， and the conversion of initial and working clearance distribution was realized using the MonteCarlo method. In the analysis of getting optimal interval of working clearance， the load distribution of bearing under different clearances was calculated based on quasidynamic analysis， and the bifurcation diagram of bearingrotor system under different clearances was plotted with theory of bifurcation of nonlinear vibration. The initial clearance interval was controlled to ensure the reliability of clearance of bearing on the basis of the optimal interval of working clearance for highly precise bearing clearance. References | Related Articles | Metrics