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15 August 2013, Volume 34 Issue 8 Previous Issue    Next Issue
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Information & Control

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Dynamic Modeling of Operation System for ElectricBus Battery Charge/Switch Stations WANG Jinkuan， LI Yan， HAN Peng， HAN Yinghua 2013, 34 (8):  1065-1068.  DOI: - Abstract ( 434 )   HTML   PDF (474KB) ( 991 )   Based on the urban construction， size of the charge/switch stations， logistics systems and other elements， a high applicable model for electric bus charge/switch systems was developed. According to the operation characteristics of buses， an automatic battery switch system was modeled. The battery logistic system data was simulated based on the realtime requirement of a battery switch system. The load of a charging station was plotted with the impact of charging. The corresponding control measures on the grid load were analyzed too. The simulation results show that the model can well describe the capacity and the operational performance of a charge/switch station in a certain area and the influence on the grid load. References | Related Articles | Metrics

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Topologybased Double Slot Routing Algorithm in Delay/DisruptionTolerant Network WANG Xingwei， WEI Yongtao， HUANG Min， WANG Junwei 2013, 34 (8):  1069-1073.  DOI: - Abstract ( 512 )   HTML   PDF (459KB) ( 524 )   In delay/disruptiontolerant network (DTN) such as city bus network， all or part of the topological information can be used for routing calculation. A topologybased double slot routing (DSR) algorithm for the DTN is proposed. The DSR algorithm divides the DTN cycle into time slots. The best path is selected from valid paths in the current and next slots. It can thus ensure that most traffic transmission are completed before link interruption and offer tolerance to predictable link interruption. In path choosing， the DSR algorithm uses transmission delay and delay jitter rate as path parameters to ensure transmission reliability and stability. It also exploits alternate paths to provide tolerance for unpredictable link interruption. Simulation and performance analysis are performed， and the results show that the asproposed algorithm is linkinterruptiontolerant with higher message delivery ratio and lower average transmission delay. References | Related Articles | Metrics

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Dynamic Short Group Signatures with Provable Security in Standard Model WANG Sifei， YUE Xiaohan， LI Yuxi， ZHOU Fucai 2013, 34 (8):  1073-1077.  DOI: - Abstract ( 451 )   HTML   PDF (346KB) ( 605 )   The existing group signature schemes are unpractical to a certain extent in performance and security. A dynamic short group signature scheme with provable security in a standard model is thus proposed on the basis of the BSZ model. The subgroup decision assumptions (SDA)， lSDH assumptions and GrothSahai proof system are used to construct the scheme with security proved in the standard model. It is shown that the asproposed scheme meets anonymity， traceability and nonframeability. It is compared with other group signature schemes in performance and security， and the results show that our scheme outperforms those in these two aspects. References | Related Articles | Metrics

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Systolic Blood Pressure Measurement Based on Volume Pulse Wave LI Han， ZHAO Hai， ZHU Jian， LI Dazhou 2013, 34 (8):  1078-1081.  DOI: - Abstract ( 876 )   HTML   PDF (614KB) ( 1840 )   The method to measure blood pressure via pulse wave transit time(PWTT)requires monitoring ECG and pulse wave signals simultaneously， which has no portability. A new noninvasive method of measuring systolic blood pressure(SBP)continuously is therefore proposed， in which the PWTT can be obtained simply through volume pulse waves. The volume pulse waves were acquired by a blood oxygen probe with red light emitting diode， and then the accelerated pulse waves were gotten through filtering， amplifying and processing the signals. The PWTT between the progressive and reflected waves of the accelerated pulse waves was calculated and the SBP was calibrated. The system was implemented using the Android cell phone and ATmega128 MCU. The experimental results indicate that there is no obvious difference between the SBP measured by the new system and by an electronic sphygmomanometer with error less than 10 mmHg. References | Related Articles | Metrics

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Dynamic Routing Algorithm Based on Multiobjective Programming for WSN LI Fangfang， LIU Dong， GAO Xianwen， YU Ge 2013, 34 (8):  1082-1085.  DOI: - Abstract ( 626 )   HTML   PDF (371KB) ( 1032 )   To balance the energy efficiency and timeliness of query processing in wireless sensor networks， a dynamic routing algorithm called MOPEH was proposed based on the theory of multiobjective programming (MOP). MOPEH combined minimumenergy (ME) and minimumhop (MH) routing strategies and took both energy cost and transmission delay as the designed objects for the routing algorithm using MOP simulation. The set of all the feasible paths between nodes was established using depthfirst searching strategy， from which the paths were chosen which energy consumption were less than the average energy consumption. A network performance function was designed according to the query requirements in order to dynamically adjust the energy efficiency and timeliness. The paths which satisfied the requirements were thus chosen from the set of the feasible paths and optimal solutions were obtained. The experiment results showed that the algorithm processed realtime queries with good energy efficiency. References | Related Articles | Metrics

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An Image Watermark Algorithm Based on Bandelet Transform LI Wenna， KONG Xiangyong， GAO Liqun， CUI Zhaohua 2013, 34 (8):  1086-1090.  DOI: - Abstract ( 440 )   HTML   PDF (784KB) ( 540 )   To improve the resistance to compression and noise attack， a kind of image watermark encryption algorithm based on bandelet transform was put forward. Arnold scrambling， chaotic modulation and BoseChaudhuriHocquenghem(BCH)error correction coding were used in the watermark processing of images， which improved the security of the digital watermarking. The BCH codes were embedded at the location where the low frequency optimal geometric flow of the coefficient for the carrier image bandelet was diagonal. The results showed that the bandelet domain embedding method overcame the block effect in the Discrete Cosine Transform(DCT) domain and inherited the advantages of the wavelet domain， which had relatively strong data hiding capacity and better attack resistance. The bandelet domain embedding method made up the shortages of the wavelet domain and had much stronger resistance to compression and noise attack. References | Related Articles | Metrics

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ETX Routing Metric with Embedded Node Moving Trajectory Prediction Algorithm SHA Yi， GUO Yibin， CHU Jiafu， ZHANG Lili 2013, 34 (8):  1091-1094.  DOI: - Abstract ( 707 )   HTML   PDF (478KB) ( 1031 )   The node moving trajectorypredicting mechanism was introduced into expected transmission count(ETX)routing metric， which worked before the ETX metrics was in operation. An auto regressive integrated moving average(ARIMA)model was developed using the historical and current location information of a node， by which the location of nodes at next time was predicted， thus the trajectory of nodes was obtained. According to the predicted results， ETX could be used for routing metric if the distance between two nodes of a link was less than the communication radius， otherwise the link was discarded. The simulation results showed that the links with high packet loss rates were selected less and the frequency of the routing interruption were reduced due to the introduction of the prediction mechanism which increased the average throughput of a network with the packet loss rate dropped. References | Related Articles | Metrics

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Medical Image Encrypting Method Based on Even Scrambling and Chaotic Mapping DAI Yin， ZHANG Hanqiu， YU Liwei 2013, 34 (8):  1096-1099.  DOI: - Abstract ( 522 )   HTML   PDF (4857KB) ( 723 )   Medical image involves privacy and other important information， so encrypting medical images during the storage and transmission is essential. In order to improve the quality of the encryption at a high speed， a segmented medical image was treated using an even scrambling method based on the Arnold mapping combined with logistic mapping for generating quasirandom numbers to control scrambling parameters. The image was further encrypted through NOR/OR operation of the pixel values. Experimental results show that the method is sensitive to the key and covers the information of an image well， and that it resists cropping and tampering attacks simultaneously， compared with the single logistic mapping method. The operations of the method proposed are simpler than that of conventional ones， so， the method meets the requirement of the encryption speed. References | Related Articles | Metrics

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Microcalcification Clusters Recognition Based on Optimized CostSensitive SVM Combinational Algorithm〓 CAO Peng， LI Bo， LIU Xin， ZHAO Dazhe 2013, 34 (8):  1100-1104.  DOI: - Abstract ( 596 )   HTML   PDF (512KB) ( 720 )   Microcalcification clusters(MCs)are important signs for early breast cancer detection. The existing initial detection methods result in lots of false positive data because of the requirements of high sensitivity. A classification strategy combining with global and local views was proposed based on MCs characteristics. The costsensitive SVM classification algorithm was employed according to different misclassification costs of true and false positive instances. In the construction of classification model， the parameters and feature subset were optimized with particle swarm method to enhance the generalization performance. The ensemble method reduces excessive false positive data but with high sensitivity， and removes redundant and irrelevant features. Experimental results show that the proposed method improves the performance of traditional methods on microcalcification clusters recognition. References | Related Articles | Metrics

Materials & Metallurgy

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Effect of DC Gradient Magnetic Field on Thermoelectric Power of Al Alloys ZHANG Jianfeng， LE Qichi， BA Qixian， CUI Jianzhong 2013, 34 (8):  1109-1112.  DOI: - Abstract ( 417 )   HTML   PDF (898KB) ( 448 )   The behavior of thermoelectric power of Al alloys in a DC gradient magnetic field was investigated. The results show that the DC gradient magnetic field leads to a decrease in thermoelectric power of liquid Al289%Fe alloys. When the magnetic field is removed， it takes a period of time for the thermoelectric power to increase gradually to the initial value. With the increasing temperature， the thermoelectric power increases rapidly， the increment increases， and the regression speed increases. This phenomenon is observed in other Al alloys melt， but is not observed both in solidstate pure Al and Al alloys in a gradient magnetic field and liquidstate Al alloys in a homogeneous magnetic field. The theory of localization was used to explain the effect of the magnetic field on the thermoelectric power. References | Related Articles | Metrics

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Multitask Application Platform of Process Control System for Hot Strip Rolling CAO Jianzhao， PENG Wen， ZHANG Dianhua 2013, 34 (8):  1113-1116.  DOI: - Abstract ( 547 )   HTML   PDF (615KB) ( 530 )   Taking the characteristics of a hot strip rolling line into account， a Windowsbased platform of the process control system was designed and developed to meet the actual requirement on the spot. The platform adopted multiprocess structure and each process adopted a new mode of “one task one thread”， which improved the system stability and reduced the coupling of functional modules. The key functions of the platform included process managing， network communicating， data collecting/managing and process tracking. Data communicating， database operating and process data recording， and strip tracking together with thread dispatching were implemented separately by these modules mentioned above. Each module was scheduled by an event signal trigger method which had shorter response time. This platform successfully ran on some hot strip rolling lines with good stability and reliability. References | Related Articles | Metrics

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Emissivity IndirectMeasurement and Analysis for Hot Rolled Strip PENG Lianggui， ZHANG Dianhua， GUO Tao， LEI Honggang 2013, 34 (8):  1118-1122.  DOI: - Abstract ( 860 )   HTML   PDF (609KB) ( 840 )   Emissivity of hot rolled strip after laminar cooling and before coiling was calculated by temperature field technology which uses CrankNicolson implicit difference method based on measured temperature data. The effects of carbon equivalent， strip thickness and strip temperature on the emissivity were analyzed. The results showed that the prime influencing factors are different under different strip temperature range. When the temperature is beyond 550℃， the strip emissivity varies between 07 and 09， and with the increasing in carbon equivalent， the accordingly strip emissivity increases smoothly. However， when the temperature is below 550℃， the strip emissivity decreases rapidly with the increasing of strip thickness， and there is no obvious relationship between strip emissivity and carbon equivalent. References | Related Articles | Metrics

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Modeling for Surface Roughness of Stainless Steel Strip in Tandem Cold Rolling CHEN Jinshan， LI Changsheng 2013, 34 (8):  1123-1127.  DOI: - Abstract ( 526 )   HTML   PDF (427KB) ( 689 )   According to the characteristics of stainless steel in tandem cold rolling and based on transfer rate and genetic factor， a set of models about surface roughness of stainless steel strips were derived theoretically. First， the surface roughness of the SUS430 stainless steel strip was studied through lubrication experiments in the cold rolling process. The effects of main factors， such as reduction ratio， initial thickness， deformation resistance， and emulsion technological parameters， etc.， on the transfer rate and genetic factor were analyzed quantitatively， with attenuation function equations developed for describing surface roughness. The surface roughness of strips at the entry of last mill was calculated approximately. Ultimately， a mathematical model of stainless steel strip surface roughness was built which was applied to the practical production. A great number of statistical results show that the relative deviation between the roughness values calculated from the model proposed and the experimental data was less than 634%， which means that the model has relative high accuracy and good generalization ability. References | Related Articles | Metrics

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Parameters Adaptation of the Rolling Force Model Based on the Objective Function in Tandem Cold Rolling CHEN Shuzong， PENG Wen， JI Yafeng， ZHANG Dianhua 2013, 34 (8):  1128-1131.  DOI: - Abstract ( 562 )   HTML   PDF (535KB) ( 716 )   In order to improve the prediction precision of the rolling force model， a method for optimizing parameters of the rolling force model based on the objective function was put forward. Through establishing the model of rolling force parameter adaptive target function， the adaption coefficients of the deformation resistance and friction coefficient models were taken as the parameters to be optimized， and the NelderMead simplex algorithm was used to search the optimal solution of the objective function so that the adaptation coefficients were obtained which fulfilled the accuracy of the rolling force. The proposed parameter adaptation method of the rolling force modeling was applied to a 1700mm 5stand tandem cold mill. Application results showed that the mean square deviation between the calculated rolling force and measured one was reduced from 129% to 32% after using the proposed parameter adaptation method， which showed that the method proposed obviously improved the accuracy of the rolling force model and met the requirement of online process control. References | Related Articles | Metrics

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Thermodynamics Model of Deoxidation in ESR Process for Large Slab Ingots GENG Xin， LI Xing， JIANG Zhouhua， LI Wanming 2013, 34 (8):  1132-1135.  DOI: - Abstract ( 619 )   HTML   PDF (377KB) ( 632 )   A thermodynamics model for deoxidation in the slag system of 12Cr2Mo1R steel with Al as a deoxidizer was developed. The equilibrium mass fraction of 12Cr2Mo1R steel with different Al additions was calculated at the interface of slagmetal substance. The dependence of the equilibrium mass fraction on the Al additions was investigated， which provided a theoretical basis to the end composition prediction with the given amount of Al and to the limits on the amount of Al according to the composition required by certain steels. The results show that， the mass fractions of Si， Mn， Al and Al2O3 increase with the increasing Al content， while the mass fractions of SiO2， MnO and FeO tend to decrease. Considering the limitation of Si， Mn and Al mass fraction， the amount of Al added in one ton steel should not exceed 02%. References | Related Articles | Metrics

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Effects of Mg on the Microstructure， Corrosion Resistance and Formability of Galvalume Coatings LI Shiwei， GAO Bo， TU Ganfeng， ZHU Guanglin 2013, 34 (8):  1136-1139.  DOI: - Abstract ( 800 )   HTML   PDF (1210KB) ( 759 )   By means of scanning electronic microscopy (SEM)， Xray diffraction (XRD)， electrochemical test and cupping test， the effects of Mg (15 wt.%) on the microstructure， corrosion resistance and formability of Galvalume(Zn55Al16Si) coating were studied. The SEM and XRD results revealed that MgZn2 phases appeared in the zincrich interdendritic area of Zn55Al16Si15Mg coating. The morphology of the corrosion product showed that magnesium eliminated the cracks in the corrosion product of Galvalume coating and enhanced the compactness of the corrosion product. The results of the electrochemical test showed that the corrosion rate of Zn55Al16Si15Mg coating was 341% of that of Galvalume coating， which means that the addition of magnesium markedly improved the corrosion resistance of the Galvalume coating. As a strengthening phase， MgZn2 strengthened the zincrich interdendritic area of the coating and decreased the cracks in the outer bending surface of the formed cup. As a result， the formability of Galvalume coatings was improved significantly. References | Related Articles | Metrics

Mechanical Engineering

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Comparison of Two Modeling Methods for Rotor System with Local Thermal Bending YAO Hongliang， ZHAI Xinting， XU Qi， WEN Bangchun 2013, 34 (8):  1140-1143.  DOI: - Abstract ( 681 )   HTML   PDF (698KB) ( 547 )   Both 2D and 3D methods can be used for modeling a rotor system with local thermal bending， but comparisons of the two methods and their applications are still not reported. The two methods were discussed in detail based on heat transfer and rotor dynamics theories in rotor system with local thermal bending. The efficiency and accuracy of the two methods were compared through analyses of thermal field， thermal deflection and thermal bending vibration of an actual rotor system. The results show that the 2D thermal field analysis has lower accuracy but higher computational efficiency， which is suitable for concentrated heat input， while the 3D method has higher accuracy but lower computational efficiency， which is suitable for dispersed heat input. References | Related Articles | Metrics

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Simulation of Multipoint Annular Rubbing Fault for a RotorStator System MA Hui， LYU Song， NAI Haiqiang， SONG Rongze 2013, 34 (8):  1149-1153.  DOI: - Abstract ( 544 )   HTML   PDF (1958KB) ( 613 )   The dynamic model for a flexible rotor system， which considered multipoint annular rubbing， was established using the finite element method based on the contact dynamics. The rotorstator multipoint annular rubbing was simulated using a pointpoint contact element. The effects of penetrating amounts， i. e. ， the difference between the vibration amplitude of the rotator without rubbing and the rotorstator gap， and the stator stiffness on the vibration responses of the system were analyzed under two types of exciting loads. The eccentricity directions of the two discs were the same (case 1) or opposite (case 2). The results show that the rubbing is serious under case 2 than that under case 1， and the stator stiffness has great influence on the rebounding intensity caused by the rotorstator rubbing and on the acceleration responses of the stator. References | Related Articles | Metrics

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Vibration Noise Analysis of Transmission Based on Explicit Dynamics ZHANG Yubai， YUAN Huiqun， YU Yinxin， ZHANG Kaifeng 2013, 34 (8):  1154-1156.  DOI: - Abstract ( 553 )   HTML   PDF (1445KB) ( 910 )   Using LS_DYNA， the finite element models of all shafts were established. Based on explicit dynamic method， the shaft vibrations were analyzed and the dynamic excitations of bearing parts were obtained. On these bases， the vibration noise of the boundary element model of the transmission shell was analyzed under bearing excitations and the surface noise distribution was obtained using the boundary element method. Thus a new method of the noise analysis for transmission was provided. The results show that the radiation noise mainly focuses on the differential and parts of the rolling bearing. To reduce the noise level， reinforcements should be added on the shell side or the thickness of the existing reinforcements should be increased. References | Related Articles | Metrics

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Prediction of Tool Point Dynamics of End Milling Processing System Using a Receptance Coupling Method LIU Yu， ZHANG Weilong， ZHANG Yimin， LYU Chunmei 2013, 34 (8):  1157-1160.  DOI: - Abstract ( 547 )   HTML   PDF (949KB) ( 628 )   The receptance coupling method for predicting tool point displacement receptance was studied to analytically predict tool point dynamical characteristics of end milling processing system. The processing system of end milling was divided into two subsystems with the parting line on the tool. The subsystem containing the main shaft is structurally complicated and hard to model analytically， so the displacement receptance was experimentally obtained， while that of the simplestructured tool subsystem was obtained using the finite element software. The two subsystems were beam units with different sections and connected by a single point. The nodes on the beam have translational and rotational DOFs. The displacement receptance of tool point was calculated based on displacement receptance of the two subsystems. Experiments were performed on 45# steel cylinders with different length， and the displacement receptance of the end point was obtained when the cylinders were assembled into holder. References | Related Articles | Metrics

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State Estimation of Robot Hydraulic Actuator Based on Extended Kalman Filter SUN Guangbin， WANG Hong， TONG Kun， HUANG Hailong 2013, 34 (8):  1161-1164.  DOI: - Abstract ( 569 )   HTML   PDF (1265KB) ( 1048 )   The hydraulic actuator in this work is an unobservable nonlinear system， for which a normal observer is infeasible. The extended Kalman filter (EKF) was thus adopted to estimate pressures in piston and rod chambers of the cylinder. The 4th order nonlinear statespace model was developed and its parameters were obtained by the GaussNewton method. The state of the hydraulic actuator was estimated using joint angle based on the EKF. The simulation results indicate that the proposed method can estimate the cylinder pressures accurately. The experimental results show that the estimated joint torque is close to the measured one， which verifies the validity of estimating hydraulic states by the EKF. A reference for statebased fault detection and control of a hydraulic actuator is thus provided. References | Related Articles | Metrics

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Structure Optimization and Finite Element Analysis of Shape Memory Alloy Coupling MA Yan， LI Wei 2013, 34 (8):  1166-1170.  DOI: - Abstract ( 555 )   HTML   PDF (1332KB) ( 692 )   In order to solve the chronic leakage problem at the tubing interface， a shape memory alloy (SMA) used for naval nuclear reactor coupling was studied. A structural optimal model for the NiTiNb shape memory alloy coupling was established. Using the genetic algorithm， the structural design of the NiTiNb pipe coupling was optimized. The NiTiNb shape memory alloy coupling was then analyzed through the thermalstructural coupled simulation using the finite element method. The results suggest that the computational results agree well with the theoretical data. Therefore， the method proposed is feasible and effective， and has great versatility and practical significance. References | Related Articles | Metrics

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Modification Research and Contact Analysis of AeroEngine Gears WANG Dan， LU Ruicheng， YAN Yutao， SUN Zhili 2013, 34 (8):  1171-1174.  DOI: - Abstract ( 703 )   HTML   PDF (999KB) ( 946 )   Based on principles of gear meshing， 3D parametric finite element model of the involute gear was built using the ANSYS parametric design language (APDL). The finite element model of single gear tooth body temperature was established， and then the bulk temperature field of gear tooth was obtained by the ANSYS， on the basis of heat transfer and friction theories. Taking the temperature distribution as the temperature load of the gear， thermal deformation was calculated by the maximum amount of modification for an involute tooth profile. Besides， the maximum amount of modification in terms of the force load on the gear was also calculated according to empirical formulas. Finally， the modification curve equation was revised through thermoelastic coupling analysis combined with the modification theory and then verified through the ANSYS contact analysis. References | Related Articles | Metrics

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Numerical Simulation of Decompression Expansion of Subcritical CO2 Through ConvergingDiverging Nozzle MA Juanli， SUN Wan， LIU Changhai， HOU Yu 2013, 34 (8):  1175-1178.  DOI: - Abstract ( 625 )   HTML   PDF (612KB) ( 746 )   Twophase flow generated from expansion of subcooled subcritical CO2 when flowing through a convergingdiverging nozzle was studied numerically using the mixture model of the Fluent with the sliding velocity neglected. Mass transfer rate between the two phases was calculated with the cavitation model under 61MPa and 29315K at the nozzle inlet. The results show that phase change occurs at the throat and the pressure drops steeply with the mass transfer rate reaching the maximum. The vapor volume fraction increases with decrease of pressure when the CO2 flows through the nozzle diverging section. When the pressure at nozzle exit gets to 165MPa， the volume fraction reaches 093. The comparison of calculated and experimental results show that the maximum relative error of pressure is less than 101% and that of temperature is less than 19%. Mechanism of the twophase flow expansion process of the subcooled CO2 through a convergingdiverging nozzle was well described by numerical simulation. References | Related Articles | Metrics

Resources & Civil Engineering

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Microseismic Event Distribution in Deep Tunnels Under the Disturbance of Blasting Excavation ZHAO Zhouneng， FENG Xiating， JIAO Kai， CHEN Tianyu 2013, 34 (8):  1179-1183.  DOI: - Abstract ( 355 )   HTML   PDF (795KB) ( 588 )   Based on the monitored microseismic data in situations with high geostress， large diameter， frequent daily blasting and strong blasting disturbance， the distribution of microseismic events occurring in the deep tunnels of JinpingⅡhydropower station under the action of blasting disturbance was investigated. The results show that the microseismic activities in the areas affected by excavation unloading are closely related to surrounding rock stress redistribution and blasting disturbance. And blasting disturbance is a main factor of triggering microseismic activities outside the influence range of excavation unloading; hence it is one of important factors for triggering the timedelayed rockburst. Moreover， the distribution area of microseismic events is associated with its distance from the sites where blasting events happen and the relative location between them. The results achieved can provide the reference for the rockburst prevention during deep tunnel excavation by drillandblast technique. References | Related Articles | Metrics

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Production Schedule Optimization in OpenPit Coal Mine GU Xiaowei， XU Xiaochuan， WANG Qing， ZHENG Youyi 2013, 34 (8):  1184-1187.  DOI: - Abstract ( 486 )   HTML   PDF (2496KB) ( 1097 )   Based on the floatingcone exclusion method and geological model of coal seam， geologically optimum pushbacks were produced in a known final pit of coal mine. A dynamic sequencing model was established and the geologically optimum pushbacks were introduced into it， with the maximum NPV (net present value) as a target function. Then the best mining path of final pit was found out as an optimal mining scheme， thus the mining sequence， production capacity and mining life regarded as three essential factors of production schedule were simultaneously optimized. A case study on an openpit coal mine shows that the mining life is 39 years， annual production capacity is 1649 million tons and the NPV is 33998 billion RMB without capacity investment taken into account. At the same time， rock and topsoil annual stripping volume as well as working face in each year are given out， which provides powerful tools for decisionmakers. References | Related Articles | Metrics

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Effect of Operating Factors of High Pressure Grinding Roll on Size of Crushed Product YUAN Zhitao， SHEN Shuaiping， XIE Qichun， LIU Lei 2013, 34 (8):  1188-1191.  DOI: - Abstract ( 556 )   HTML   PDF (663KB) ( 680 )   Lowpurity hematite was crushed with high pressure grinding roll， and effects of operating factors such as roller surface pressure and speed， and ore moisture content on size of crashed products were studied. With the increase of roller surface pressure， the overall size became smaller， and size of products crushed in the roller center was distributed more concentratedly， while at the roller edge was more evenly. The products in the center became finer when the roller speed was increased into certain range， however， if further accelerating speed， no size change was observed. Roller speed had no obvious effect on the product size at edge. When the ore moisture content was increased， no obvious change was detected in product fineness. The product size distribution in the center was more concentrated， while at the edge it was more even. References | Related Articles | Metrics

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Fatigue Life Prediction of FRP Reinforced Bridge Under Constant Amplitude Loading LI Ming， ZHU Fusheng， WANG Lili 2013, 34 (8):  1192-1195.  DOI: - Abstract ( 572 )   HTML   PDF (533KB) ( 538 )   Based on the assumption of linear asymptotic superposition， the formulae for computing a stress intensity factor of an FRPreinforced bridge under threepoint bending were deduced theoretically. The fatigue crack propagation of the bridge was analyzed through experiments， and it was verified that the empirical formula for the crack mouth opening displacement (CMOD) can be used to calculate the CMOD of a beam under threepoint bending， by which the critical effective crack length of the bridge in a fracture model was calculated. Fatigue crack growth was quantitatively described via the stress intensity factor in linear elastic fracture mechanics， thus the fatigue life of an FRPreinforced bridge was forecasted. References | Related Articles | Metrics

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Seismic Performance of ThreeBay ThreeStory Steel Frame with Steel Plate Shear Walls MU Zaigen， XUE Yuan， LI Liming 2013, 34 (8):  1196-1200.  DOI: - Abstract ( 535 )   HTML   PDF (2540KB) ( 564 )   The vertically stiffened steel plate shear wall (SPSW) with twoside constraints is a kind of new structural form. To reveal the synergistic effect mechanism between steel frame and wall， and then look for reasonable stiffness match between the steel walls， beams and columns， two threebay threestory models (1∶3 scale) were studied experimentally under cyclic quasistatic loading. The component failure mechanisms were summarized. Besides， the influences of different SPSW layouts on the structural system were investigated. The results show that the vertically stiffened SPSW with twoside constraints has better seismic performance， and such structural form is particularly suitable for areas with high seismic intensity. References | Related Articles | Metrics

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Subgrade Settlement of HighSpeed Railway in Seasonal Frozen Soil Area ZHANG Shuang， TANG Chunan， ZHANG Xiangdong 2013, 34 (8):  1202-1205.  DOI: - Abstract ( 621 )   HTML   PDF (1491KB) ( 676 )   Subgrade settlement at the Sujiatun section of Hada highspeed railway was simulated using the finite element software ADINA， and it was concluded that the subgrade settlement did not meet the specification if the CFG (cement flyash grave) piles were not applied to subgrade. By changing the parameters of CFG piles， including cushion modulus， cushion thickness， the diameter and length of piles， and spacing of piles， the relationship between the parameters and subgrade settlement was investigated， with the settlement values obtained on conditions of different parameter combinations. The result shows that the subsidence value is minimal when the cushion thickness is 350mm， cushion modulus is 120MPa， pile spacing is 2m， and the diameter and length of the pile are 05m and 95m， respectively. References | Related Articles | Metrics

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Numerical Estimation on Jacking Force and Resistance Relieving Effect of LargeDiameter Pipe Jacking in Shenyang JIA Peng， JIAO Chenglong， ZHANG Wenchao 2013, 34 (8):  1206-1209.  DOI: - Abstract ( 547 )   HTML   PDF (1532KB) ( 798 )   The experience of pipe jacking in sand and gravel conditions in Shenyang is limited， especially for pipes with large diameter.So， a numerical method of forecasting the jacking force during construction was put forward based on the initial jacking force， and then jacking forces calculated from numerical simulation were compared with insitu monitored values. Finally， the effect of resistance relieving by using different proportion of thixotropic fluids was numerically analyzed and the jacking forces of seven fluids were contrasted. Simulation results indicate that the numerical method used in this work is feasible in forecasting the jacking force， thus being helpful in reasonably arranging the intermediate jacking stations. It is also shown that the water content in thixotropic fluids has significance influence on the resistance relieving effect of pipe jacking and the optimized proportion of bentonite and water is 1∶9. References | Related Articles | Metrics

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Surveying and Analyzing Residents Awareness of Light Pollution GAO Chengkang， LIU Zhengwen， TANG Hanmei， CHEN Shuteng 2013, 34 (8):  1210-1212.  DOI: - Abstract ( 601 )   HTML   PDF (333KB) ( 917 )   Survey and analysis were carried out for awareness of light pollution in Shenyang from 464 valid questionnaires collected. The results show that residents aware of light pollution are less than 10%， and up to 20% residents do not know concept of light pollution at all. Though 90% residents think that light pollution has severely affected their sleep quality， the majority (about 639%) choose to endure instead of coping with it by the law， indicating low light pollution awareness of the residents. References | Related Articles | Metrics