Journal of Northeastern University(Natural Science)

Fault Estimation for Sampling Control System with Discretion

LI Ning， FENG Jian

2013, 34 (7): 913-916. DOI: -

Abstract ( 342 )

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To study a class of linear time invariant sampling control system with periodic sample， the following steps were carried out. Firstly， the definition of system norm was given， and then the system was dispersed simultaneously by norm invariant transformation and step invariant transformation based on the definition of system norm to get the discretion model of the system. Secondly， fault detection problems of H_/H∞， H2/H∞ and H∞/H∞ were considered， and the form of the optimal filter was provided. At the same time， based on the design idea and method of the optimal filter for discrete system， the design method and form of the fault estimation observer were given out， and the essential condition of the error equation asymptotic stability was gotten by structuring Lyapunov function. What’s more， the fault estimation adaptive weighting matrix Γ and parameter θ were solved by Matlab LMI toolbox as well. At last， a numerical example was given to illustrate the effectiveness of the proposed method.

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Navigation and Control for Wheeled Intelligent Car Based on Electromagnetic Effect

ZHANG Yunzhou， YANG Bing， LI Long， JIANG Jianjun

2013, 34 (7): 917-921. DOI: -

Abstract ( 400 )

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With intelligent transportation system as the background， a navigation and control system of wheeled car was designed and implemented on the basis of the electromagnetic effect. The model cars would run in a microtrafficnetwork environment. According to the real geometry parameters of the sandtable， feasible route for the cars was built and the directionturning strategy of intersect junction with RFID tags was designed. Multiple conceptual models could run along with the designated path correctly. Theoretical analysis was proposed for electromagnetic navigation line. System architecture and sensors layout were introduced in details as well as the judgment of car’s deviation， including distance and direction. Experimental test showed that the proposed navigation and control system can work stably and lead the wheeled car run correctly in complex route net.

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Enhanced FCM Algorithm Combined with Structure Feature for Image Segmentation

CUI Zhaohua， ZHANG Ping， LI Hongjun， GAO Liqun

2013, 34 (7): 922-925. DOI: -

Abstract ( 509 )

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To improve the ability of fuzzy Cmeans clustering algorithm (FCM) for complex texture structure images， a new fuzzy Cmeans clustering algorithm (EnFCM) was proposed by combining image structure features. Firstly， the input image was meanfiltered， and the filtered image was added to the original image to form the new image for the subsequent operations. Secondly， the 2D Gabor filtering function was adopted to extract texture structure feature for the new images to replace the gray level similarity measurement in the traditional FCM algorithm. Finally， a new distance measure function was proposed to calculate the distance between the nodes and the clusters. The simulation results showed that more precise segmentation results could be obtained from complicated texture structure images using the presented algorithm.

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Pornography Filtering Algorithm Based on Classification Space Multiinstance Learning

LI Bo， CAO Peng， LI Wei， ZHAO Dazhe

2013, 34 (7): 927-930. DOI: -

Abstract ( 491 )

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In order to solve the problem that the traditional pornography filtering algorithms are hardly to be used for the complex Internet environment， a novel filtering algorithm was presented based on multiinstance learning by building classification space. Firstly， Hessian matrix was used in YCgCr space to detect image feature points which are instances of the image， and then LBP operator was expanded to YCgCr space. Secondly， YCgCrLBP operator was constructed to describe the image instances. Finally， classification space model based on frequency statistical theory was proposed， and cosine similarity was used to complete image recognition. Different data sets were used to make comparison. The results showed that using the proposed method， the accuracy is increased compared with the large skin contented images filtering by the conventional skin proportional method， and the description of the proposed method is improved compared with the general multiinstance learning method. What’s more， better experimental results were obtained， which indicated the practical value.

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Hybrid Ant Colony Optimization Algorithm for Service Selection Problem

YIN Hao， ZHANG Changsheng， ZHANG Bin

2013, 34 (7): 931-934. DOI: -

Abstract ( 501 )

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To tackle the QoSbased service selection problem， a novel efficient hybrid ant colony optimization algorithm was proposed. In this algorithm， a skyline query process was used to filter the candidates related with each service class， by which the search space could be greatly shrunk and the solving efficiency was improved in the case of not losing good candidates. Then， varying dynamic construct graph was designed to guide the ant search directions based on a clustering process and some promising search areas could be found after the ACO search process. In order to make a further exploitation for these areas， a heuristic strategy was introduced and used to make a deeper local search. The proposed approach was evaluated experimentally by using standard real datasets and synthetically generated datasets， and compared with the recently proposed related service selection algorithms. The experiments indicated very encouraging results in terms of the quality of solution， and the processing time required.

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Mechanical Properties and Controlling Degradation Rate of MgZnCa Alloy

ZHANG Yajing， ZUO Lijing， XING Xiaole， WANG Fan

2013, 34 (7): 935-938. DOI: -

Abstract ( 434 )

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The MgZnCa alloy formed by casting and hot extrusion was systematically studied. The microstructure and mechanical behaviors of the alloy were analyzed by an optical microscopy and universal testing machine. The hydroxyapatite (HA) coatings on the surface of this magnesium alloy were deposited using a biomimetic technique. The HA coatings were characterized by XRD， and the morphology of the sample surface was observed by SEM. The degradation rates of the samples without and with HA coatings were researched invitro corrosion. The results indicated that the tensile strength and compressive strength of MgZnCa alloy were close to the human bones， and the values were 365MPa and 338MPa， respectively， and the yield strength， elongation and elastic modulus of the alloy were 360MPa， 1025%， 4169GPa， respectively. The degradation rates of the samples with HA coatings was slower than that of the samples without HA coatings on the surface.

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Fabrication of Al2O3Based Porous Ceramic with Closed Pores by Superplastic HighTemperature Foaming Method

YUAN Lei， HE Zhenbao， YU Jingkun

2013, 34 (7): 939-942. DOI: -

Abstract ( 643 )

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Al2O3based porous ceramic with closed pores was fabricated utilizing the superplastic deformation properties of Al2O3based ceramics with nano and submicron Al2O3 powder as raw materials， MgO as the dopant and SiC as the hightemperature foaming agent. The effects of different particle size of Al2O3 and different amounts of MgO on the apparent porosity， closed porosity and microstructure of Al2O3based porous ceramic were studied. The phase composition of Al2O3based porous ceramic was also investigated， and the mechanism of forming closed pores in the sintering process of Al2O3based porous ceramics was discussed. The results indicated that the apparent porosity of Al2O3based porous ceramics fabricated with nano Al2O3 powder was lower than that formed with submicron Al2O3. The apparent and closed porosity were 13% and 132%， respectively， and the diameter of the closed pores was about 1~2μm. The phases in the porous ceramic were Al2O3 and MgAl2O4， which generated by the completely reaction between Al2O3 and MgO in the billet.

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Microstructure and Performance of DP590 Cold Rolled Steel Strip After Heat Treatment Processes

HUO Gang， LI Zhenxing， CEN Yiming， LI Guodong

2013, 34 (7): 944-947. DOI: -

Abstract ( 1068 )

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In order to accelerate the development and application of the domestic dual phase steel， the effects of the heating speed， intercritical annealing temperature， overaging temperature， and the time of overaging on the microstructure and properties of DP590 dual phase steels were studied by a CAS300Ⅱannealing simulator. The results showed that the yield strength and tensile strength both increased and the elongation and product of strength and ductility both decreased with the increase of the heating speeds between 5 and 60℃/s. The yield strength and tensile strength both decreased first， then increased， the elongation and product of strength and ductility both increased with the increase of intercritical annealing temperatures between 780 and 850℃， The yield strength increased， the tensile strength decreased， the elongation increased generally， the yield ratio increased apparently with the increase of the overaging temperature between 260 and 400℃. When the overaging temperature was 280℃， the yield strength and tensile strength both decreased， the elongation and product of strength and ductility decreased first， then increased with the increase of the over aging time within the range of 240~480s.

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Fracture Behavior of Surface Oxide Scale in Cold Rolling

HE Yongquan， JIA Tao， LIU Zhenyu， LI Jun

2013, 34 (7): 948-951. DOI: -

Abstract ( 538 )

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The fracture of oxide scale on the hotrolled low carbon steel strip in cold rolling without pickling was investigated. It is found that microcracks were formed in the oxide scale near the entry to the roll bite due to the elastic deformation of the steel strip near the gap of the rolls， running perpendicular to the rolling direction. Density of cracks increased with the distance closer to the bite entry. The oxide scale was cracked only with the reduction of single pass lower than 16%， while the reduction of single pass was higher than 16%， the oxide scale began to spall. When the interface shear stress was beyond the adhesive strength between the oxide scale and the steel surface， spalling and powdering of the oxide scale from the surface of the steel strips will occur. Under the same total reduction condition， the multipass rolling is favor to protect the integrality of the oxide scale.

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Optimization of Working Roll Curve of FourHigh Aluminum Foil Rolling Mill

GONG Dianyao， XU Jianzhong， DI Hongshuang， LEI Yine

2013, 34 (7): 952-955. DOI: -

Abstract ( 522 )

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Aim at the doublerib wave problem which happened during rolling decoration foil production using a fourhigh mill in certain domestic factory， according to the shape control theory， this kind of strip shape obtained due to the equivalent convexity in the corresponding area of the working roll was excessive. The effects of the factors such as thermal extension and cooling， the roughness and the curve of the working rolls on the equivalent convexity were analyzed. The key factor affected the equivalent convexity of the corresponding area of the working rolls in the worksite. The expression equations of the curve of the working roll was deduced based on references， and the comparisons were made among the curves with different halfangles and different convexity， respectively， therefore， the optimized curve of the working roll under current working conditions was selected. The doublerib wave problem was eliminated after increased the halfangle of the curve of the working roll in the worksite experiment.

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Effect of the Increasing Percent of High Chromium VanadiumTitanium Magnetite on Quality of Oxidized Pellets

TANG Jue， ZHANG Yong， CHU Mansheng， XUE Xiangxin

2013, 34 (7): 956-960. DOI: -

Abstract ( 730 )

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The two optimization measures including “fine grinding high chromium vanadiumtitanium magnetite” and “replacement of the practical production iron ore with cheap finer Oukong powder(imported)” were adopted. Effects of the percentage of the addition of the high chromium vanadiumtitanium magnetite powder on the quality of oxidized pellets were investigated and the feasibility of adding high chromium vanadiumtitanium magnetite powder was explored. Through both optimization methods， when the ratio of high chromium vanadiumtitanium magnetite was 40%， the compressive strength was 2475N per one and 2005N per one，respectively， while the reduction expansion ratio was 192% and 16% correspondently. These parameters all met the requirements of the practical blast furnace production. So the increasing percent of high chromium vanadiumtitanium magnetite in raw material was achieved and the target of 900000 tons per year of the iron and steel company was reached.

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A New Method for the Measuration of Assimilation Characteristics of Iron Ore Powder

WU Keng， WANG Meng， ZHAO Yong， WANG Chongmao

2013, 34 (7): 961-965. DOI: -

Abstract ( 643 )

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The advantages and disadvantages of the measuration methods currently used of assimilation reaction between iron ore powder and CaO were indicated. The iron ore powder was first melted into liquid phase at the interface wetting CaO which led to the assimilation reaction that formed calcium ferrite. Discriminated methods of the parameters of the assimilation reaction such as starting and finishing temperatures were confirmed by Xray diffraction analysis. Upon this， the assimilation characteristic number taking the actual sintering temperature as the reference temperature was established. This assimilation characteristic number was a dimensionless number including kinds of important information during the assimilation reaction process， such as the heating rate， the assimilation reaction temperature and the assimilation reaction velocity， which overcame the shortcomings of the previous methods without considering the assimilation reaction process， and avoided using multiple parameters to characterize the assimilation reaction process.

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Experimental Study on New Process for Selective Reduction and Separation of BoronBearing Iron Concentrate

FU Xiaojiao， YU Hongxiang， LIU Zhenggen， CHU Mansheng

2013, 34 (7): 966-969. DOI: -

Abstract ( 511 )

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In view of disadvantages of present boron and iron separation technology， a new process for selective reduction and separation of the boronbearing iron concentrate was proposed， which was verified by the thermodynamic feasibility analysis and laboratory tests. The laboratory experiments indicated that for the boronbearing iron concentrate in Fengcheng city of Liaoning province with Fe and B2O3 mass fraction of 5605% and 386%， respectively， the optimized parameters of selective reduction and separation were as followed: the carbon ratio 08~ 10， the reduction temperature 1275~1300℃， the reduction time no less than 20min， the particle size of coal about 0075mm and the magnetic field strength of the separation 50mT. The selected product was the iron powder with high metallization， which could be used in steel production through further processing. The tailings of separation were high grade sources containing boron， which could be used as the superior raw material in boron industry.

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Effects of Flap Angles on the Charging Procedure of Flap Distributors

CHEN Lisheng， LUO Zhiguo， YOU Yang， ZOU Zongshu

2013, 34 (7): 971-974. DOI: -

Abstract ( 621 )

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The charging system of COREX melting gasifier involved one coalgimbal chute distributor and eight DRIflap distributors. The effects of the flap angle on the charging law of the DRIflap distributors were analyzed by physical experiments and discrete element method (DEM) mathematical modeling simulation. Physical experiment results showed that when the flap angle was small， the burden flow trajectory was more concentrated; however， when the flap angle was large， the burden flow trajectory scattered. The mathematical modeling simulation results of the burden flow trajectory and pile shape agreed well with the physical experiment results， moreover， the detail information of the pile structure and the radial porosity profile can be further obtained by the mathematical modeling simulation， which provided some references to adjust reasonably gas flow distribution in COREX production field.

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Physical Simulation on Circulating Flow Rate and Mixing Characteristics in RH Vacuum Refining Process

HAN Jie， WANG Xiaodong ， BA Dechun

2013, 34 (7): 975-978. DOI: -

Abstract ( 682 )

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Based on a prototype of 180t RH vacuum refining equipment in a steel plant， the physical simulation experiment device was established according to the similarity criterion. The threelevel orthogonal experiments with the influence of two factors such as the gas blowing angle and gas flow rate were studied in the water model experiments， which revealed thorough understanding of the circulating flow conditions in RH vacuum refining process， and provided technical references for the decision of process and operating parameters. The results showed that both the gas flow rate and the gas blowing angle influenced the refining efficiency， of which the gas flow rate had more significant influence. The optimization argonblow scheme was that the minimum mixing time was obtained with the nozzle angle of 45°when the gas flow rate was 20m3/h. While for the different gas flow rates， the increased amplitude of the circulation flow rate decreased with the increase of the gas blowing angle， and the optimal gas blowing angle was between 25 ° and 35 °.

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Numerical Simulation on Gas Flow Affected by Constructional Parameters of Pelletizing Shaft Furnaces

DONG Hui， FENG Junsheng， LI Peng， CAI Jiuju

2013, 34 (7): 980-984. DOI: -

Abstract ( 525 )

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According to the gas solid packed bed dynamic theory， the mathematical model of the gas flow in the pellet shaft furnace (PSF) layer was established， and the boundary conditions of the mathematical model were determined. The basic law of the gas flow in PSF was studied by using the manual programming simulation， further more the influences of the structural parameters of PSF on the gas flow were discussed. The results showed that in the structural parameters， the width of the internal vertical air channels and roasting zone， the height of preheating roasting zone were the major factors that influenced the gas flow in PSF. With the increase of the width of internal vertical air channels or the height of preheating roasting zone and the decrease of the width of roasting zone， the upward cooling gas flow tended to decrease， while the downward roasting gas tended to increase. At the same time， the change of the width of internal vertical air channels or the roasting zone and the height of preheating roasting zone， also led to the change of the ratio of the roasting gas and the cooling gas， namely the change of the ratio of air volume， which was the main factor to decide the gas flow in PSF.

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Complex Heat Transfer Model in an Electroslag Remelting Mold

LIU Peng， LI Baokuan， WU Wenyuan

2013, 34 (7): 985-989. DOI: -

Abstract ( 599 )

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In the view of the complex heat transfer procedure in the ingot (slag pool)/slag crust/air gap/mold wall/cooling water in an electroslag remelting crystallizer， the heat transfer of the crystallizer was defined 5 modes according to the thermal shrinkage of ingots and slag crust， the distribution of gap and slag， etc. The boundaries of the modes were divided based on the maximum axial temperature gradient. The integral mathematical model of the complex heat transfer procedure of the ingot (slag pool)/slag crust/air gap/mold wall/cooling water interface was established through integrated utilization of these five heat transfer modes. At the same time， the multipoint continuous temperature measuring system was also developed. The measured temperature values were used as the boundary conditions， thus the temperature distribution of the ingot (slag pool)/slag crust/air gap/mold wall/cooling water interface and heat fluxes along the radial direction were solved. The regular pattern of the redial temperature variation in five heat transfer modes of this complex heat transfer system was analyzed by the simulation.

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Optimization of Extraction of Copper from Bioleaching Solution Based on the Taguchi Methods

MA Zhiyuan， YANG Hongying， CHEN Guobao， LI Haijun

2013, 34 (7): 990-993. DOI: -

Abstract ( 628 )

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An optimization method of extraction of copper from bioleaching solution bearing high iron using LIX984N as an extractant was proposed based on Taguchi method for SNR (signal noise ratio) and variance analysis of the extraction rate and baciextraction rate. The results showed that in the process of extraction the extraction agent volume fraction and the phase ratio (V(O)/V(A)) were important factors affecting SNR ， and their contributions to the extraction rate reached 32744%， and 34180%， respectively. Extraction time was a significant factor to SNR while pH value was an nonsignificant factor in the extraction process. The optimized parameters of the extraction process were as follow:extraction agent volume fraction 30%， volume ratio of organic material to water 2∶1， extraction time 600s and initial pH value 15. The phase ratio (V(O)/V(A)) and baciextraction time were significant factors to SNR while temperature was an nonsignificant factor in the baciextraction process. The optimized parameters of the baciextraction process were as follow:volume ratio of organic material to water 1∶2， baciextraction time 600s， and temperature 30℃. Through extraction—baciextraction—electrodeposition experienments under the optimized processing condition， the extraction rate and baciextraction rate of copper reached up to 9991%， and 9856%， respectively， while the current efficiency reached up to 92594%.

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Dynamic Characteristics of DualRotor MultidisksRotor System

LI Chaofeng， LIU Guangchao， ZHOU Shihua， WEN Bangchun

2013, 34 (7): 994-998. DOI: -

Abstract ( 565 )

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Based on finite element theory， a dualrotorbearing system dynamic model was built， which is adopted to analyze the change law of the system critical speed with the bearing stiffness and innerouter rotor speed ratio. The accuracy of the calculated results was verified. The research found that the increase of the supporting bearing stiffness will result in that of the critical speed of system. Not much influence on the critical speed exists when the speed increases to a certain degree. The effects of supporting stiffness on the critical speed are not consistent. Besides， the intermediate bearing affects the critical speed little. When the inner rotor is given a main synchronous antiprecession incentive， the system critical speed will decrease with the increase of the speed ratio. The speed of synchronous positive precession will increase along with the increase of the speed ratio. However， the critical speed will perform a contrary regularity on main synchronous antiprecession incentive given to external rotor.

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Study on Undercutting and Dynamic Performance for Asymmetric Helical Gear with LowNumber Teeth

TIAN Xing， LI Wei

2013, 34 (7): 999-1003. DOI: -

Abstract ( 529 )

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The equation of asymmetric rackcutter in the normal plane was established based on gear machining principle. Through matrix transformation with the homogeneous coordinate， the profile equation of generating gear was derived. The tangent vector of undercutting point on the surface of generating gear tooth is zero. The range of addendum modification coefficient when undercutting doesn’t occur was obtained， providing the basis for parameter selection in gear design. Based on the finite element model of gear engagement， the change of the tooth root acceleration and Von Mises stress within a meshing cycle was analyzed. In addition， the influences of different torque and speed on tooth root impact stress were investigated. The relationship between the impact stress and gear top modification was achieved. The results showed that for asymmetric helical gear with lownumber teeth， three directions of x， y and z are all important to gear vibration. Rotating speed affects gear impact more significantly than torque， and appropriate modification will reduce the impact stress.

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Potential Distribution Inside the Debye Layers of the Nanochannel

ZHANG Wei， BA Dechun， SHAN Linting

2013, 34 (7): 1005-1008. DOI: -

Abstract ( 855 )

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Based on the net charge conservation theory， a new theoretical framework was proposed to describe the ion concentration distribution and the potential distribution accurately in thin nanochannels of overlapped Debye layers. To verify whether the double electrical layers were overlapped， the classical PoissonBoltzmann equation was firstly employed to calculate the effective Debye layers thickness according to its definition. The double layers were overlapped when the effective Debye thickness exceeds the half height of the channel. Taking channel height， PoissonBoltzmann equation and reservior ion concentration into account， the assumption of net charge conservation can then be used to deduce the potential distribution and corresponding ion concentration. The calculated results showed that the electric potential difference between the surface and midplane will decrease with the reducing height of channel， which agrees well with the experimental data.

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EqualDisplacement Pump Controlled Hydraulic Synchronous System Compensated by Valve Controlled Oil Spill Branch

ZHANG Fubo， WANG Guiqiao， JIAO Mingmu， LI Nan

2013, 34 (7): 1009-1011. DOI: -

Abstract ( 468 )

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A highly reliable and lowcost solution was put forward to solve the poor precision problem of the conventional equaldisplacement pump controlled synchronous circuit. An oil spill branch， made of a highspeed onoff valve， was added on each pump’s pressure pipeline of the conventional circuit. By using the PWM (pulse width modulation) method to control each highspeed onoff valve， highprecision multicylinder synchronization was realized. Detailed hydraulic principle diagram and the synchronization control method were presented as well. The scheme has been used in a twocylinder synchronous system of a mill entranceguide device for nearly one year， with the synchronous absolute error being kept under 15mm. The practical results showed that the scheme is worth promoting for its simplicity and practicality.

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Geochemical Discrimination of Tectonic Environments of Volcanic Rocks of Yixian Formation in Jianping of Western Liaoning

PENG Yandong， HUANG Fei， XING Dehe， ZHANG Zhibin

2013, 34 (7): 1012-1016. DOI: -

Abstract ( 419 )

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Petrology， geochemistry， isotope geochronology of the volcanic rocks distributed in PingzhuangMachang basin of Jianping of western Liaoning were studied. The results showed that the volcanic rock is the Cretaceous. The volcanism of Yixian formation may be divided into two subcycles. The volcanic rocks mainly consist of rhyolites， trachyte and trachyandesites. The volcanic rocks belong to the highK calcalkaline magmatic series. The volcanic rocks are characterized by components of high SiO2， Al2O3， K2O and Na2O， and comparatively low MgO and TiO2. The volcanic rocks are obviously enriched in large ion lithophile elements (K， Rb， Sr， Zr， Ba， Pb and Li)， and depleted in high fieldstrength element (Nb， Ti， P)as well as compatible elements (Co， Ni， Cr and V). The volcanic rocks is rich in LREE. There is a slight negative Eu anomaly and no Ce anomaly. A detailed geochemical discrimination of the selected elements allowed us to identify that the volcanic rocks of Yixian formation mainly derived from the partial melting of lower crust materials， but also has been contaminated by upper crustal materials during its ascent process in some degree. The volcanic rocks of Yixian volcanic cycle were generated in response to lithosphere inhomogeneous extension in the continental intraplate orogenic belt. They have the basic characteristics of continental intraplate volcanic rocks.

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Search of Key Block in Complex Rock Mass Slope and Support of Excavated Slope

WANG Shuhong， RAO Wenjie， GUAN Xiangxiang， MU Xijiang

2013, 34 (7): 1017-1021. DOI: -

Abstract ( 488 )

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The information of the structural planes was collected using a contactless photography measurement technique， and then it was imported into GeoSMA3D system which was developed by author to establish the spatial numerical model of rock mass slope. In this way， the key blocks can be defined in terms of dimensions and positions. Then 3DEC was used to simulate the slope excavation and excavation after anchor support. The results showed that the excavation of the rock slope causes the rock internal stress redistribution and a wide range of the shear plastic zone， and the displacement and velocity are heavily concentrated on the joints in the vicinity of the excavation face. The directions of displacement and velocity lean to the free face and their magnitude tends to increase gradually. So if no appropriate supporting measures are applied， the overall instable failure of rockmass slope will happen. After anchor support， the potential slip surface of the slope is controlled and the slope is in a steady state as a whole.

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Numerical Simulation on Concealed Goaf at the Iron Mine Based on High Density Resistivity Method

WANG Ende， MEN Yekai， ZHANG Zhongjie， WU Minggang

2013, 34 (7): 1022-1025. DOI: -

Abstract ( 568 )

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The high density resistivity method， together with two devices of Winner and dipole suitable for field operation being selected， was used to measure the electric resistivity of main rock and ore in Anshan-Benxi area. According to the determined basic parameters， three kinds of goaf detection models were built respectively for simple geological conditions， conditions with surrounding rock and complex geological conditions. The regularities of electric field distribution and characteristics of goaf anomaly reflected in different geological conditions were discussed in detail. The results indicated that the existence of geological bodies with unequal electrical properties affects the reflection of goaf anomaly， which is often reflected in the form of secondary anomaly or weak anomaly in complex geological conditions. With the application of these models to the interpretation of goaf detection results of iron mines in Anshan-Benxi area， several goafs are predicted accurately， thus testifying the effectiveness of these models.

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Numerical Test on Size Effect of Macromechanical Parameters of Jointed Rockmass

FENG Yanfeng， YANG Tianhong， YU Qinglei， ZHANG Zhe

2013, 34 (7): 1027-1030. DOI: -

Abstract ( 415 )

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Based on the MontCarlo method， the structural plane network of jointed rockmass was generated， and it was used to build the finite element model of rockmass through numerical code RFPA2DDIP， where the microstructure of rockmass was considered. Numerical tests on six rockmass samples with different size of rocks were carried out under uniaxial compression loading， the stressstrain relationship of jointed rockmass was studied， and the size effect of compressive strength and deformation modulus were analyzed. After the failure process of jointed rocks with different scale were examined， the failure process of 1500mm×1500mm rockmass was described. The results showed that compressive strength and deformation modulus declines with the increasing size of jointed rockmass， but the variable range became narow gradually， the compressive strength tends to stabilize faster with the increasing size， and the fitting relation about exponential decay was obtained. The failure processes of jointed rockmass with different scale was similar. The method can offer a new tool to research macromechanical parameters of jointed rockmass.

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Stability Analysis of the Sixth Truck Organization’s Spoilbank in Gongchangling Mining Company

SUN Xiaogang， XING Jun， ZHANG Shiyu， WANG Jie

2013, 34 (7): 1031-1034. DOI: -

Abstract ( 481 )

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The similarity between the spoilbank operated by the sixth truck team in Gongchangling Mining Company and other existing spoilbanks was compared in terms of lithology， structure， natural environment， dominant factor of deformation and developmental stages. The physical and mechanical parameters of granular media， halfcompaction body， compaction body and bedrock in waste pile were determined. FLAC3D was used to simulate and analyze the slope stability of spoilbank， and it was compared with the slope stability coefficient obtained by Bishop method and Janbu method. The results showed that the first terrace slope is unstable， and the existed potential slip band is at a distance of about 13m away from the slope edge. The second terrace slope is stable， and its limit dump height is 108m. There are safety problems when the limit dump height is reached， therefore， reinforcement measures are needed.

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Application of AcidBase Potential Scale in Structure Performance Study of Flotation Reagents

WANG Jizhen， YIN Wanzhong

2013, 34 (7): 1035-1038. DOI: -

Abstract ( 568 )

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Acidbase potential scale was introduced to overcome the difficulties caused by acidbasic theory in the quantitative research on structure performance of flotation reagents， and to expand the scale of application of acidbasic theory. The selective criterion was presented， which is the function of acidbase potential scale and frontier molecular orbital energy level of flotation reagents. With this selective criterion， the structure performance of RA315 as anion reverse flotation collector of hematite and sulphide mineral collector was studied. The conclusions are in accordance with the flotation test results， which indicates that acidbase potential scale plays a great promotion role in the quantitative research on structureactivity of flotation reagents.

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Test Research on Recovery of Iron from Rare Earth Tailings by Depth Reduction Roasting-Low Intensity Magnetic Separation

LIN Hai， XU Xiaofang， DONG Yingbo， ZHANG Wentong

2013, 34 (7): 1039-1044. DOI: -

Abstract ( 522 )

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A process of depth reduction roasting-low intensity magnetic separation was introduced to the rare earth tailings with an iron grade of 1625%. The effects of processing parameters， such as the type and dosage of reducing agent， roasting temperature， roasting time， grinding fineness and magnetic field intensity on the iron grade and recovery of the concentrate were investigated. And the means of SEM， XRD were used to analyze the rare earth tailings， the roasted products and the iron concentrate. The results showed that an iron concentrate with TFe grade of 8076% and recovery of 9324% was obtained under the condition of bituminous coal dosage of 30%， roasting temperature of 1300℃， roasting time of 60min， grinding fineness of -0074mm accounted 75% and magnetic field intensity of 118kA/m. After depth reduction， ironbearing minerals in the tailings， such as hematite， limonite and iron silicate，translated into simple substance iron. Compared with the conventional separation methods， the iron concentrate grade and recovery increased more significantly and the gangue minerals composition was simple， which was helpful for enrichment and recovery of fluorite.

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Reliability Analysis of Fiber Concrete Containers for Nuclear Waste Storage

ZHANG Lu， ZHAO Wen， LI Yi

2013, 34 (7): 1045-1048. DOI: -

Abstract ( 567 )

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According to the result of creep test on the fiber concrete which mixed basalt fibre and polypropylene fiber， creep equation was fitted through Burgers model. The progressively decreasing modulus of elasticity of fiber concrete with time was summarized through isochronous stressstrain curve， together with the ultimate strain and ratio of tensile and compressive strength tensile compressive tested at the laboratory， the variations of tensile strength with time were got as the reliability evaluation criterion. Second， ANSYS software was used to analyze the temperature stress of the container wall under the thermomechanical coupling condition in the service of 300 years. At last， taking account of uncertainty of thermal parameters， the failure probability of tensile stress arise from decaying heat was solved by MonteCarlo method. The failure probability tends to rise， increasing greatly within 100 years， and increasing slightly between 100a and 300a， until a failure probability of 064% after 300a. This proved that the degradation of fiber concrete was the key factor that caused the decline of durability for nuclear waste storage container.

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Experiment Research on High Strength ConcreteFilled Double Skin Hollow Composite Columns Under Axially Loading

ZHANG Ni， WANG Lianguang， WEN Jianping

2013, 34 (7): 1049-1052. DOI: -

Abstract ( 527 )

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To investigate the axial compression performance for the GFRP high strength concrete short columns， four composite columns with different cross sections were tested under axial compressive load so as to understand the working mechanism and failure mode. The results showed that， in the early stage of the load， the combination column GFRP tube is not bound on the concrete. As the load increases， the GFRP tube surface appears white streaks and a slight noise is noted. In the limit state， the GFRP tube is pulled off accompanying with a huge sound. The carrying capacity of the GFRP tubehigh strength concretethe steel tube composite column is about 37% higher than that of the GFRP tubehigh strength concreteGFRP tube composite column. In the foundation of uniform theory， the formula of ultimate bearing capacity is established， and the theoretical calculations are in good agreement with the experimental results.

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Study on Private Equity Investment Fund Regulation Based on the Grey Game Theory

ZHU Can， SHI Liangyuan

2013, 34 (7): 1057-1060. DOI: -

Abstract ( 422 )

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Targeting at the asymmetry and opaqueness of information， and based on the grey game theory， the game behaviors of private equity investment participants in the process of regulating and being regulated were studied. The parties’ expected revenue of the private equity investment fund with government regulation was discussed， and the equilibrium points in different situations were located according to the expected revenue. The results indicated that if the revenue of illegal operations is more than that of legal operations with government regulation， investors are likely to opt for illegal operations. Therefore， the government should set up special regulators or laws to regulate private equity investment and increase the punishment towards investors’ illegal operations so as to reduce the possibility of such acts. Besides， the thirdparty selfregulatory organizations should get involved under certain conditions.

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Nonconvex Retracts Constructed by Quasiconvex Functionals

ZHANG Guowei， ZHAO Tuhua

2013, 34 (7): 1061-1063. DOI: -

Abstract ( 485 )

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The nonempty， closed convex subset in Banach space is a retract. Two nonconvex retracts are constructed in Banach spaces by the uniformly continuous nonnegative quasiconvex functional. One of the retracts is a subset of cone， and the other does not need to be restricted in a cone， but needs the infinitedimensional space and the even functional. The earlier results are extended where nonconvex retracts are constructed by the uniformly continuous nonnegative convex functionals and an example is given in the space of continuous functions.

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