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15 February 2016, Volume 37 Issue 2 Previous Issue    Next Issue
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Information & Control
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Information & Control

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A Parameter Self-tuning Model for Wind Power Prediction ZHAI Jun-chang， GE Yan-feng， LIANG Peng， GAO Li-qun 2016, 37 (2):  153-156.  DOI: 10.12068/j.issn.1005-3026.2016.02.001 Abstract ( 552 )   HTML   PDF (276KB) ( 744 )   To improve the prediction accuracy of wind power， a parameter self-tuning model is proposed. The sliding window weighted recursive least square (SWWRLS) method is used to establish the wind power prediction model， which emphasizes most recent data in the prediction， ruling out the interference of historical data. Less memory space is used in the weighted recursive model， and the adaptability of the prediction model to the external environment data is increased. Finally， the simulation is carried out on the real historical data of the wind farm in Liaoning with support vector machine， Kalman filter and SWWRLS methods， separately， and the simulation results show the superiority of the proposed method. References | Related Articles | Metrics

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Key Point Extraction Based on Voting Strategy CHEN Hong ， WU Cheng-dong， CHEN Dong-yue， LU Zi-wei 2016, 37 (2):  157-161.  DOI: 10.12068/j.issn.1005-3026.2016.02.002 Abstract ( 839 )   HTML   PDF (609KB) ( 870 )   False corners and inaccurate orientation in key point extraction algorithms will result in low matching rate and low image registration accuracy and speed. A new method is proposed to solve the problem. A set of strongest interest points is worked out in the algorithm to eliminate false corners. Interest points in the set have high characteristic strength and meet several criteria. The same coordinate is applied to ensure orientation accuracy. With similarity transformation， brightness change and noise， a series of images are tested with the new algorithm proposed and traditional algorithms， respectively. The results show that the new algorithm has better adaptability and anti-noise performance， and is more effective in feature points extraction. References | Related Articles | Metrics

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Torsion Sensor Based on Polarization-Maintaining Photonic Crystal Fiber Loop Mirror with an Output Port Probe WU Di， ZHAO Yong 2016, 37 (2):  161-164.  DOI: 10.12068/j.issn.1005-3026.2016.02.003 Abstract ( 519 )   HTML   PDF (472KB) ( 781 )   Focused on measuring twist angle precisely，a torsion sensor was proposed which was based on a section of polarization-maintaining photonic crystal fiber(PM-PCF) outside an optical fiber loop. Due to the low thermal coefficient of PM-PCF， the PM-PCF was used as the sensing element. When the PM-PCF is rotated with a certain angle， the birefringence of the PM-PCF will change either. The interference within the fiber loop mirror was observed via the optical spectrum analyzer (OSA). The response of the sensor was deduced theoretically and experimentally demonstrated. Experimental result showed that the sensitivity of the developed torsion sensor could reach 0.0617nm/(°) in the range from 0° to 101° and a resolution of 0.16° was achieved since the OSA had a wavelength measurement resolution of 0.01nm. In addition， the sensor has an ultra-low temperature sensitivity of -0.6pm/℃. The proposed fiber-optic torsion sensor is attractive due to its compact size， low cost， insensitivity to temperature and suitability for long-distance transmission beyond what conventional sensors can offer. References | Related Articles | Metrics

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Credibility-based Algorithm for Merging Vote Lists YANG Hong-guo， SHEN De-rong， KOU Yue， YU Ge 2016, 37 (2):  165-169.  DOI: 10.12068/j.issn.1005-3026.2016.02.004 Abstract ( 486 )   HTML   PDF (295KB) ( 677 )   In a voting system， each voter makes a preferential list about candidates， thus a large amount of ordered lists are obtained. To get a comprehensive voting result from these lists， an effective lists merging algorithm is required， which can analyze these lists data and output a comprehensive list. A merging algorithm based on credibility is proposed. Through analyzing the data of lists， numerous ranking messages are extracted， then the credibility of them is formulated and measured， with which the final comprehensive list is computed such that those ranking messages with high credibility could play a more influential role in the final ranking result. Experimental results fully indicate that the algorithm proposed can dig out the credibility about ranking information more effectively， thus attaining the merging results more accurately. References | Related Articles | Metrics

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Mathematical Modeling of Pulse Wave Based on Lognormal Function ZHAO Hai， DOU Sheng-chang， LI Da-zhou， CHEN Xing-chi 2016, 37 (2):  169-173.  DOI: 10.12068/j.issn.1005-3026.2016.02.005 Abstract ( 720 )   HTML   PDF (592KB) ( 855 )   Daily monitoring health status needs long time， so the amount of health data is massive. In order to simplify the data， the existing mathematical methods of modeling pulse wave were analyzed which use two to four Gauss function to fit the pulse wave. Then， the mathematical modeling method of pulse wave based on Lognormal function was presented. A cycle of pulse wave was modeled by using four Lognormal functions. The starting time points of the four Lognormal functions were adjusted based on the physiological characteristics of the pulse wave， and the performance of the model was analyzed and compared with the existing methods. The results show that， compared with the existing methods， the Lognormal function model not only has a higher fitting accuracy， but also has better computational complexity， thus being more suitable for the big data application to daily health monitor in the body area network. References | Related Articles | Metrics

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Software Design of Instantaneous Heart Rate Detection Based on Phase Demodulator for Smart Phones LI Han， ZHAO Hai， CHEN Xing-chi， LI Da-zhou 2016, 37 (2):  174-178.  DOI: 10.12068/j.issn.1005-3026.2016.02.006 Abstract ( 683 )   HTML   PDF (459KB) ( 744 )   Rarely software in the smart phone market can detect instantaneous heart rate quickly and precisely， because a threshold calculated based on a period of measurement is always necessary when using a derivative based algorithm. A phase demodulator based method was proposed to improve the performance of Android software. The pulse wave detected by cell phone camera was multiplied by a sine wave reference signal and then processed by a low pass filter to extract phase. The phase could be used to calculate the frequency beat to beat. Experimental results on an Android smart phone indicated that there was no obvious difference of instantaneous heart rate between the new method and the ECG method. Compared with derivative based and filter bank based algorithms， less phone resources was needed for the new algorithm and instantaneous heart rate could be obtained more quickly. References | Related Articles | Metrics

Materials & Metallurgy

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Intercritical Austenite Stabilization of a Mn-Al TRIP Steel HU Zhi-ping， XU Yun-bo， TAN Xiao-dong 2016, 37 (2):  179-183.  DOI: 10.12068/j.issn.1005-3026.2016.02.007 Abstract ( 593 )   HTML   PDF (796KB) ( 768 )   The intercritical austenite stabilization of Fe-0.2C-7Mn-3Al steel was investigated by MMS-200 thermo-mechanical test machine in the lab. The microstructure evolution and the partitioning process of C， Mn were characterized and analyzed by using SEM， EPMA， TEM and XRD. The results show that there are always 25%-30% bulky flattened ferrite at different intercritical annealing temperatures. As the intercritical annealing temperature increases， the retained austenite content in the microstructure increases first and then decreases， with the volume fraction being 10.2%-32.5%. The retained austenite and the intercritical ferrite are located with the lath shape， and the lath width is 200-300nm. The optimized annealing temperature is 750℃. The synergistic effect of C， Mn and Al promotes the austenite stabilization during intercritical annealing， which causes the partitioning process with less time of the tested steel. References | Related Articles | Metrics

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Effect of Cr Content on High-Temperature Oxidation Behavior of High-Manganese Austenitic TWIP Steel YUAN Xiao-yun， ZHAO Yang，CHEN Li-qing 2016, 37 (2):  184-188.  DOI: 10.12068/j.issn.1005-3026.2016.02.008 Abstract ( 643 )   HTML   PDF (1373KB) ( 804 )   Through oxide weight gain experiment，SEM and XRD analysis， the effects of Cr content were studied on the high-temperature oxidation behavior， the microstructures and phase compositions of oxidation scale of a high-manganese austenitic twinning-induced plasticity (TWIP) steel oxidized at 700℃ for 8h. The results show that with increasing the Cr content， the anti-oxidation ability of this high-manganese austenitic TWIP steel increases. When the Cr content is 1.13wt%， the mass gain of the steel oxidized at 700℃ for 8h is about 30μg/mm2， while the Cr content increases to 3.95wt%， the mass gain decreases to 3μg/mm2. Moreover， with increasing the Cr content， the compactness of oxide scale increases， and there are significant differences in the composition of oxide scales. References | Related Articles | Metrics

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Effect of Carbides and Alloy Elements on Grain Corrosion Morphology in Acid Liquid Film ZHANG He-jia， CHEN Li-qing， LI Jian-jie ， LI Dong-liang 2016, 37 (2):  189-193.  DOI: 10.12068/j.issn.1005-3026.2016.02.009 Abstract ( 552 )   HTML   PDF (1156KB) ( 715 )   Taking the steels #10， #65 and W6Mo5Cr4V2Al as experimental materials， the grain microstructure and alloying element distribution after corrosion treatment in acid environment were observed and analyzed by optical microscope， scanning electron microscope and electron probe. The effects of existing forms of carbides and alloying elements on the grain corrosion morphology in these steels were also studied. The results show that the corrosion morphology of grains is related to distribution of carbides in steel and that C in the form of solid solution and Cr， Al added in steel can significantly improve the corrosion resistance of the steel. In acid environment with electrochemical corrosion， the electrode potential level of each phase in microstructure is the essence that determines whether or not the grains are liable to be corroded， while grain boundary is apt to be corroded or not is also mainly related to the electrode potential level of phases at grain boundary. References | Related Articles | Metrics

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Photocatalytic Degradation of Dioctyl Phthalate with Fe2O3 Nanoparticles HU Jian-she， LI Yan， LI Song， QIN Gao-wu 2016, 37 (2):  193-197.  DOI: 10.12068/j.issn.1005-3026.2016.02.010 Abstract ( 605 )   HTML   PDF (521KB) ( 736 )   Hollow Fe2O3 particles were prepared by hydrothermal synthesis. The effects of Fe2O3 concentration， initial concentration of dioctyl phthalate (DOP)， pH value and H2O2 concentration on the photocatalytic degradation of DOP aqueous solution were experimentally studied using halogen lamp as light source. The photocatalytic degradation mechanism of DOP with Fe2O3 particles was studied with GC-MS technology. The results showed that without H2O2 addition， the photocatalytic degradation rate of DOP is the greatest when the Fe2O3 concentration， DOP initial concentration， and pH value were 100mg/L， 20mg/L and 7， respectively. During the degradation process， the branched chain of benzene ring degrades first， then the benzene ring is opened， and the ultimate products are CO2 and H2O. References | Related Articles | Metrics

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Influence of Oxygen Enrichment Rate on Reduction Behavior of Titanomagnetite Pellets ZHENG Chang-le， SHAO Qiu-jun， ZHANG Jian-liang， WANG Guang-wei 2016, 37 (2):  198-203.  DOI: 10.12068/j.issn.1005-3026.2016.02.011 Abstract ( 661 )   HTML   PDF (870KB) ( 765 )   The reduction process of titanomagnetite concentrate pellets was studied under the simulated condition of blast furnace with different oxygen enrichment rate. The microstructure of the pellets during reduction was observed by scanning electron microscopy. The distribution of different elements in ores was identified by energy dispersive spectrometry. The kinetics of the reduction process was also analyzed. The results show that both the reduction rate and reaction rate increases with the increase of oxygen enrichment rate. Al atoms migrate and get enrichment in high titanium content iron ores， eventually Al and Ti atomic number ratio is 1∶3. Al is likely to solute into titanium iron oxides to form a kind of composite iron compound which results in the restrain of reduction. Three models were used to analyze the reduction process comparatively， and it was shown that the hybrid model was in good agreement with the whole process. The kinetic parameters of pellets reduction process were calculated using the hybrid model. The results exhibit that with the increase of the rate of oxygen enrichment from zero to 79%， the reduction activation energy decreases from 26.5kJ/mol to 19.68kJ/mol. References | Related Articles | Metrics

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An Optimization Model for Casting Start Time Decision of Continuous Caster in Steel Plant GONG Yong-min， ZHENG Zhong， LONG Jian-yu， GAO Xiao-qiang 2016, 37 (2):  203-207.  DOI: 10.12068/j.issn.1005-3026.2016.02.012 Abstract ( 703 )   HTML   PDF (363KB) ( 764 )   From the aspect of the resource balancing of the hot-metal/liquid-steel in a steel plant， a mixed integer linear programming model with the objective of maximizing the total benefit of continuous casters was established for casting start time decision of continuous caster (CSDCC). The model was solved by YALMIP optimizer based on MATLAB. Application tests were conducted with the instances from the practical production process in a steel plant to evaluate the proposed model. The results show that the casting start time of continuous casters can be predicted accurately， which is beneficial to make a feasible schedule， to stabilize the production conditions for the shifting of working groups， and to reduce the quantity of hot-metal/liquid-steel stored in the production line. The CSDCC model provides a useful tool for steel plant to determine the optimized casting start time of continuous caster. References | Related Articles | Metrics

Mechanical Engineering

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Transformation Mechanism of Microstructure in Hardening Layer Under the PSHG SHI Xiao-liang， LIU Ming-he， ZHANG Xiu-ming， XIU Shi-chao 2016, 37 (2):  208-212.  DOI: 10.12068/j.issn.1005-3026.2016.02.013 Abstract ( 659 )   HTML   PDF (578KB) ( 712 )   In order to study the features of surface hardening layer and the formation and variation mechanism of metallographic structure under pre-stressed hardening grinding (PSHG)， the 45 steel was processed with the PSHG experiment. The surface hardening layer with little residual stress was obtained from it. The surface hardness was measured and its metallographic structure was observed. Combining experimental result with the simulation of grinding temperature field， we studied how the pre-stress influenced the metallographic structure such as martensite. It is shown that the high temperature in the grinding process largely weakens the yield limit of 45 steel. A smaller pre-stress would result in plastic deformation. The parent-phase-hardening and strain-inducing-phase-changing resulting from plastic deformation have comprehensive effect on the martensitic phase transformation. This indicates that the pre-stress restrains the phase transformation firstly and then promotes it. References | Related Articles | Metrics

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Numerical Fitting of Surface Hardness Based on BP and GA in Point Grinding Low Expansion Glass MA Lian-jie， GONG Ya-dong， YU Ai-bing， CAO Xiao-bing 2016, 37 (2):  213-217.  DOI: 10.12068/j.issn.1005-3026.2016.02.014 Abstract ( 586 )   HTML   PDF (609KB) ( 699 )   The changing trend of surface hardness with process parameters was analyzed， and the surface hardness was tested by grinding low expansion glass in quick-point. Based on BP neural network and single factor tests in quick-point grinding， a series of one-dimensional models were built for surface hardness and process parameters by the least-squares fitting. The accuracy of the model was tested by coefficient of correlation. The results show that the model has high accuracy. The multivariate models about surface hardness and process parameters were proposed after analyzing one-dimensional models. Based on the genetic algorithm， the multivariate numerical models were built for surface hardness according to the results of orthogonal experiments. The accuracy of multivariate model was tested by the verification experiment. The test results indicate that the model has high accuracy. References | Related Articles | Metrics

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Experimental Study on Surface Quality in Micro-grinding of Superalloy K445 ZHOU Yun-guang， GONG Ya-dong， WEN Xue-long， ZHU Zong-xiao 2016, 37 (2):  218-222.  DOI: 10.12068/j.issn.1005-3026.2016.02.015 Abstract ( 586 )   HTML   PDF (493KB) ( 812 )   To explore the micro-grinding surface quality of nickel-based superalloy， orthogonal experiments of three factors and five levels on nickel-based superalloy K445 were performed using a micro-grinding tool with #500 grains and 0.9mm diameter. The influencing factors on the surface roughness were clarified according to the range analysis: the feed rate was a dominant factor， followed by spindle speed and grinding depth. The optimized parameters combination was as follows: feed rate f○m=20μm/s， the grinding depth a○p=6μm and the feed speed v○g=58kr/min， on which the surface roughness R○a=462nm， being minimum. Then， how the factors such as spindle speed， feed speed， grinding depth and overhanging length affected grinding surface quality was analyzed through a single-factor experiment so as to provide important theoretical basis for fabricating micro nickel-based superalloy workpiece. References | Related Articles | Metrics

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Numerical Stability Analysis for Fluid Structure Conjugate Heat Transfer on Moving Interface ZHAO Qian-li， SUN Zhi-li， TONG Cao， CHAI Xiao-dong 2016, 37 (2):  222-226.  DOI: 10.12068/j.issn.1005-3026.2016.02.016 Abstract ( 683 )   HTML   PDF (459KB) ( 710 )   The numerical stability of stable heat transfer along moving fluid-structure interface was investigated. Taking the Dirichlet-Robin conditions into account， the interface movement was designated by velocity. The most common configurations (finite volume method for fluid domain and finite element method for solid domain) were used to discretize the fluid-structure system and perform numerical computation， respectively. Great emphasis was put on stability of numerical treatments when the interface moving with the adoption of the Goudonov-Ryabenkii theory normal mode analysis method. An optimal curve composed of coupling coefficient and velocity was finally obtained， which verified that the discrete system would reach fastest convergence rate and definite stability if the values of coupling coefficient and velocity come from this curve. These conclusions will provide a reference for designers to select reasonable parameters during numerical simulation. References | Related Articles | Metrics

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Numerical Simulation of Piston Heat Transfer Enhanced with Nanofluids in Gallery LIU Hao， BAI Min-li， WANG Peng， WANG Yu-yan 2016, 37 (2):  227-231.  DOI: 10.12068/j.issn.1005-3026.2016.02.017 Abstract ( 464 )   HTML   PDF (896KB) ( 690 )   Using high efficient heat transfer fluids can effectively improve the cooling performance of the piston in gallery. So diamond and Cu nanoparticles (50nm) were added into the engine oil to prepare the cooling nanofluids used as the cooling medium for piston cooling gallery. Based on the liquid-solid coupled thermodynamic method， the numerical simulation was carried out to investigate the influence of the cooling nanofluids on the heat transfer. The result shows that the temperature of piston can be reduced by using nanofluids with the volume fractions of 1%，2% and 3%. The cooling performance of diamond nanofluids is revealed better than that of the Cu ones. References | Related Articles | Metrics

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Optimization of Wind Turbine Thick Airfoils Using Improved Multi-objective Particle Swarm Algorithm CHEN Jin， GUO Xiao-feng， SUN Zhen-ye， LI Song-lin 2016, 37 (2):  232-236.  DOI: 10.12068/j.issn.1005-3026.2016.02.018 Abstract ( 640 )   HTML   PDF (740KB) ( 751 )   Considering the low structural performance of wind turbine airfoils designed just with aerodynamic performance as an optimization objective， a new multi-objective optimization method is proposed based on improved multi-objective particle swarm optimization， which balances aerodynamic and structural performance of airfoils. The airfoils with thickness of 40% are parametrically described using the wind turbine airfoil integrated theory. The optimization objectives are the maximum lift-drag ratio when designing attack angles and the maximum inertia moment about the chord axis， with such requirements as stalling characteristics， sensitivity to leading edge roughness and design lift at off-design condition considered together. The Pareto-optimal set of airfoils is obtained. The representative airfoils in the set outperform the airfoil (DU00-W2-401) in terms of aerodynamic and structural performance. References | Related Articles | Metrics

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Research on Method and System for Quick Measurement of Blade Surface QU Xing-tian， LIU Ji-ming， YANG Xu， LIU Xiao-long 2016, 37 (2):  237-242.  DOI: 10.12068/j.issn.1005-3026.2016.02.019 Abstract ( 557 )   HTML   PDF (689KB) ( 651 )   3D data from blade surfaces can be measured using contact or non-contact methods. A new fast measurement method was proposed based on the non-contact method of equidistance measurement. On the basis of the theoretical model data， feature points were extracted from the blade feature section curve with the improved method of straight angle and were compared with original data， thus the Hausdroff distance was calculated. On the premise of the fitting accuracy， the number of measurement points was reduced. A hardware system and software were developed to realize the non-contact equidistance measurement and feature point fast measurement. Finally， two sets of experiments for measuring complex blade were carried out. The results of data processing and error analyzing confirm the feasibility of fast measurement method. References | Related Articles | Metrics

Resources & Civil Engineering

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Numerical Simulation of Mechanical Properties of Columnar Jointed Basalt Under Unloading Condition JIN Chang-yu， HOU Xiao-le， LIU Dong， CUI Rui-rui 2016, 37 (2):  243-248.  DOI: 10.12068/j.issn.1005-3026.2016.02.020 Abstract ( 640 )   HTML   PDF (875KB) ( 778 )   Columnar jointed basalt in Baihetan hydropower station is jointed rock mass formed by the combined cutting effect of original joint and aphanitic micro-cracks. Due to the difference of born modes， structures， attitudes and mechanical properties， the failure mode of columnar jointed basalt under various stress states is diverse. In this paper， D-CRDM method was used to simulate unloading process of columnar jointed basalt， and to analyze the failure mechanism and mode of columnar jointed basalt combining with in-situ AE test. This study indicates that in the unloading process， original joints are easy to cause surface spalling in tension state whereas aphanitic micro-cracks were inclined to induce internal cracks of surrounding rock in tension or compression and overall collapse of rock mass. The research results are justified by in-situ observations， and meanwhile， it provides a reference in the selection of supporting methods for underground cavern. References | Related Articles | Metrics

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Experimental Study on Axial Swelling Mechanical Properties of Static Cracking Agent DAI Xing-hang， ZHANG Feng-peng， QIU Zhao-guo， XU Xiang-xin 2016, 37 (2):  248-252.  DOI: 10.12068/j.issn.1005-3026.2016.02.021 Abstract ( 686 )   HTML   PDF (515KB) ( 708 )   Focused on the axial swelling mechanical behavior of static cracking agent (SCA)， an axial-output method was proposed to measure the swelling pressure of SCA and a measurement system and its core steel cylinder component were designed. The swelling pressure of SCA was measured using the axial-output method and the external pipe method respectively， and the effects of pipe diameter on axial swelling pressure and output rate were analyzed through the contrast of pressure on the condition of different pipe diameters. The result shows that the axial-output method is accurate for the measurement of swelling pressure. Under the fixed height-diameter ratio， the axial swelling pressure increases with the increase of the diameter size. The capacity of SCA axial-output decreases because of the self-sealing effect when the diameter is smaller than 50mm， and the axial and radial swelling pressures are almost identical and the output rate of axial pressure is up to 100% when the diameter is larger than 150mm. References | Related Articles | Metrics

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Effect of Parallel Separation of Fe and Ti on High-Intensity Magnetic Separation of Micro-fine Ilmenite GUO Xiao-fei， YUAN Zhi-tao， SHEN Shuai-ping， LI Li-xia 2016, 37 (2):  253-258.  DOI: 10.12068/j.issn.1005-3026.2016.02.022 Abstract ( 604 )   HTML   PDF (854KB) ( 646 )   The separation test of -3.2mm V-Ti magnetite ore ultra-finely crushed by HPGR was carried out with the process of parallel separation of Fe and Ti. The effect of high-intensity magnetic separation on ilmenite was investigated. When the crushed ores with grind fineness of -74μm accounted for 80%， the liberation degree of the product crushed by HPGR increased by 0.58% and the number of iron oxide in the ores with fineness of -19μm+11μm decreased by 1.38%， compared with that by Jaw crusher. The TiO2 recovery could increase by 5.11% and the content of the product with -19μm could reduce by 2.62% in high-intensity magnetic concentrate， compared with the product crushed by Jaw crusher and separated by the process of stage-grinding and stage-separating. The force analysis on ilmenite with different sizes in the separation space show that， as the particle size decreases gradually， the specific resistance on ilmenite increases sharply and the specific magnetic force reduces， so ilmenite particle is more difficult to be captured by magnetic field. The process of parallel separation of Fe and Ti can reduce the amount of newly formed micro-fine ilmenite in the separation， improving the performance of high-intensity magnetic separation of ilmenite. References | Related Articles | Metrics

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Research on Processing Mineralogical Characterization of the Paigeite Ore LI Zhi-hang， HAN Yue-xin， GAO Peng， YING Ping 2016, 37 (2):  258-262.  DOI: 10.12068/j.issn.1005-3026.2016.02.023 Abstract ( 896 )   HTML   PDF (1046KB) ( 728 )   The chemical composition， phase composition， occurrence state of element， dissemination relationship and size distribution of the paigeite ore were analyzed by optical microscope， chemical analysis， XRD and SEM analysis. The results show that mineral composition of the paigeite ore is very complex. Main boron minerals are szaibelyite and paigeite， boron content in szaibelyite accounting for 89.01% of total boron content. Main iron mineral is magnetite， iron content in magnetite being 85.60% of the total iron content. Serpentine is the main gangue mineral. The dissemination relationship among szaibelyite， magnetite and serpentine is complex， and dissemination particle size distribution of different minerals is uneven. Dissemination particle sizes of szaibelyite， magnetite and serpentine are coarser， while that of paigeite is fine. References | Related Articles | Metrics

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Effect of Several Collectors on Flotation of Low-Grade Nickel Sulphide Ore ZHANG Xu，FENG Ya-li， LI Hao-ran， ZHANG Shi-yuan 2016, 37 (2):  263-267.  DOI: 10.12068/j.issn.1005-3026.2016.02.024 Abstract ( 790 )   HTML   PDF (802KB) ( 765 )   Effect of butyl xanthate， butylamine aerofloat and thiamine esters used alone and in combination on flotation of low-grade nickel sulphide ore were studied. The results showed that the nickel grade of rougher concentrate was up to 3% when butyl xanthate or thiamine esters was used alone for flotation of nickel sulphide ore， but recovery was low; when butylamine aerofloat was used alone， the nickel grade of rougher concentrate was up to 2% and recovery was up to 57%. When the combination collector of butylamine aerofloat and thiamine esters was used， the flotation recovery of low-grade nickel sulphide ore could be improved effectively. Infrared spectroscopic analysis of butyl xanthate， butylamine aerofloat and thiamine esters used alone and in combination was conducted， and functional mechanism of combination collectors on flotation of nickel sulphide ore was explained. References | Related Articles | Metrics

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Characteristics of Soil Hydraulic Parameters and Impact Factor Analysis for Saline-alkali Soils in the Western Jilin Province LIU Cai-hong， BIAN Jian-min， WANG Yu 2016, 37 (2):  268-272.  DOI: 10.12068/j.issn.1005-3026.2016.02.025 Abstract ( 625 )   HTML   PDF (285KB) ( 526 )   To explore the spatial variation characteristics and the impact factors of the soil hydraulic parameters for the saline-alkali soils in the western Jilin Province， we measured the soil-water characteristic curve(SWCC)， soil bulk density， salt content， moisture and mechanical composition in 0-20， 20-40， 40-60， 60-80， 80-100cm soil layers of saline-alkali and non- saline-alkali soil. The van Genuchten (VG) model was used to describe and solve parameters of SWCC. The results show that the VG model is suitable to describe the SWCC of the saline-alkali soils. There are significant differences of SWCC and K○s between the saline-alkali and non- saline-alkali soils. For all the soils， the θ○s and n show weak spatial variability， the θ○r and α are moderate spatial variability， while the Ks of the spatial variability is strong for the saline-alkali soils (CV=109.09%) and has moderate spatial variability for non-saline-alkali soils (CV=51.09%). Soil mechanical composition， the soil salt content and pH value are the main impact factors for hydraulic parameters. References | Related Articles | Metrics

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Spatial Pattern of Foliar δ○13C in C3-dominated Grasslands and Its Responses to Climatic Factors in Inner Mongolia of China ZHOU Yong-chun， CHENG Xi-lei， FAN Jiang-wen， XU Xin-yang 2016, 37 (2):  273-279.  DOI: 10.12068/j.issn.1005-3026.2016.02.026 Abstract ( 459 )   HTML   PDF (707KB) ( 677 )   In order to explore the pattern and climatic control of foliar δ13C， 126 samples of C3-plant species were collected from 47 areas in the Inner Mongolia during its August prosperous season. The geographic parameters of each site were recorded by GPS， and climatic information of each site was extracted from Meteorological Database of the Chinese Ecological Research Network. Foliar 13C/12C ratios were determined by an isotope mass spectrometer. The results show that the increasing trend of C3-plant foliar δ13C excursion changes positively with the increase of altitude， but negatively with the increase of longitude and latitude degrees. Climatic factors controlling the C3-plant foliar δ13C variations are mainly involved in the amount of seasonal rainfall and atmospheric pressure， as well in negative relationships， which control spatial distribution of the C3-plant foliar δ13C. In addition， variations of foliar δ13C show nothing in trend of the temperature changes here. References | Related Articles | Metrics

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Wind-induced Response Suppression of Transmission Tower-Line System Using a Robust and Semi-active Controller MA Yong-quan， QIU Hong-xing 2016, 37 (2):  279-284.  DOI: 10.12068/j.issn.1005-3026.2016.02.027 Abstract ( 514 )   HTML   PDF (680KB) ( 621 )   The robust H2/H∞controller designed by multi-objective optimization theory was applied to suppress the wind-induced dynamic response (WIDR) of the transmission tower-line system (TTLS). The uncertain parameters (mass， damping and stiffness) were introduced into perturbed matrixes in vibration (both in-plane and out-plane of the TTLS) state equations， and the H2/H○∞_MCO semi-active control strategy was proposed by the linear matrix inequalities (LMI) tool box in the MATLAB and modified clipped-optimal (MCO) control algorithm. An cat’s head-type TTLS with ultra high voltage was used as an example， and the WIDRs of the example under non-control (NC)， passive control (PC)， constant increment (CI) semi-active control and H2/H○∞_MCO semi-active control were computed， respectively. The consequences indicate that the vibration suppression effects of the H2/H○∞_MCO on tower displacements， tower accelerations and tower bottom internal forces (shear forces and bending moments) are obviously superior to those of NC， PC and CI. References | Related Articles | Metrics

Management Science

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Method for Intuitionistic Uncertain Linguistic Multi-attribute Group Decision Making: Based on Attribute Correlation CHEN Xi， LIU Yun-zhi， FAN Zhi-ping 2016, 37 (2):  285-290.  DOI: 10.12068/j.issn.1005-3026.2016.02.028 Abstract ( 478 )   HTML   PDF (231KB) ( 702 )   A method for intuitionistic uncertain linguistic multi-attribute group decision making is proposed in consideration of attribute correlations. First， some basic concepts and terminologies of intuitionistic uncertain linguistic variables are introduced， and the distance formula for intuitionistic uncertain linguistic variables is given. Then， based on the direct relationship matrices of the attribute sets， the weight of each attribute is determined by using DEMATEL method. And the experts’ decision matrices are aggregated into the group decision matrix. Furthermore， the positive (negative) ideal point vector is constructed， and the weighted distance between each alternative and the positive (negative) ideal point vector is calculated based on the proposed distance formula. On this basis， the similarity coefficient of each alternative is calculated. The ranking of alternatives is obtained. Finally， to illustrate the feasibility and potential application of the proposed method， an empirical analysis of selecting the risk response strategy for a project is given. References | Related Articles | Metrics

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Competitiveness Evaluation on the Sci-tech Human Resources in China’s Regional Central City ZHANG Lan-xia， FU Jing-yao， JIANG Hai-tao， CHE Lin-na 2016, 37 (2):  290-294.  DOI: 10.12068/j.issn.1005-3026.2016.02.029 Abstract ( 587 )   HTML   PDF (247KB) ( 692 )   Focused on six regional central cities (RCCs) which play such roles as leading， radiation， distribution， an indicator system is constructed for evaluating RCCs’ competitiveness of sci-tech human resources， and then the competitiveness is evaluated by using the analysis method of conforming to natural rules based on the individual advantages and characteristics， with the RCCs’ competitiveness advantages and their ranking clarified. On the basis， the relevant government departments can develop sci-tech human resource planning and related policies to upgrade the competitiveness of sci-tech human resources of RCCs in China. References | Related Articles | Metrics

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Retailers’ Optimal Service Decision Under the Background of Countervailing Power LI Kai， LI Wei 2016, 37 (2):  295-299.  DOI: 10.12068/j.issn.1005-3026.2016.02.030 Abstract ( 433 )   HTML   PDF (411KB) ( 606 )   Given that the existing studies have not been concerned with the impact of countervailing power on retailers’ service decision， three optimal service decision models were constructed， including the model in which suppliers vertically integrate， the model in which retailers have no countervailing power and the model in which chain retailers have countervailing power. Moreover， the impacts of countervailing power on retailers’ optimal service decision and the overall service levels on the market were analyzed. It was found that chain retailers’ service levels increase with the rise of their countervailing power. However， local retailers’ service levels will first reduce and then rise with the increase of chain retailers’ countervailing power. Moreover， the overall service levels on the market will increase even excessively when chain retailers have countervailing power. Finally， an example was given to verify the conclusions of the current study and to analyze the sensitivity of service to the base of market demands and the degree of service competition. References | Related Articles | Metrics

物理学

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Properties of Powder-in-Tube Nb3Al Superconductor Wire Prepared Using RHQT Method CHEN Chuan， BAI Zhi-ming， ZHANG Ping-xiang 2016, 37 (2):  300-304.  DOI: 10.12068/j.issn.1005-3026.2016.02.031 Abstract ( 731 )   HTML   PDF (743KB) ( 684 )   A new apparatus was designed and fabricated for rapid heating and quenching of powder-in-tube (PIT) Nb/Al precursor. Short superconducting Nb3Al samples were obtained after transformation annealing at 800℃ for 10h. The SEM images indicated that the Nb3Al phase was well formed. However， small amount of Nb2Al exists near the Ta tube，while a few of Nb exists in the wire. Superconducting properties of the samples were studied by four probe method in cryocooler. The transport critical current density of the Nb3Al without Cu is 66.5A/mm2 at 10.9K in the self field， and the critical temperature is in the range of 15-18 K. References | Related Articles | Metrics