Journal of Northeastern University(Natural Science)

Effect of Power Grid Interaction Disaster on Identifying Critical Lines and Nodes of Power Grid

HUANG Bo-nan， LI Yu-shuai， SUN Qiu-ye， ZHANG Hua-guang

2016, 37 (10): 1369-1373. DOI: 10.12068/j.issn.1005-3026.2016.10.001

Abstract ( 805 )

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Firstly， the slow and fast dynamic processes of the complex networks were given and analyzed respectively for the power grid and the disaster， and the analytic strategy of the reciprocal impact between the power grid and disaster was proposed， in which twelve aspects of the impact were studied and discussed in detail. A novel method was proposed to identify the critical lines and nodes of the power systems on the basis of the maximum flow theory and reciprocal effect between the power grid and disaster. A synthetic performance index was defined as the basis of identification which not only could reflect the internal operation characteristics but also the external operation characteristics of the power system under the influence of disaster. Finally， an example of the power grid in Tibet was provided to test the proposed method， and the result showed that the method can effectively identify the critical lines and nodes under the influence of the disaster， and is appropriate for vulnerability estimation of power system influenced by disaster， which demonstrates the rationality and validity of the proposed method.

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Consensus-Based Distributed Asymmetric Power Sharing Control in Microgrids

KIM Sung-hyok ， ZHANG Hua-guang， SUN Qiu-ye， ZHOU Jian-guo

2016, 37 (10): 1374-1378. DOI: 10.12068/j.issn.1005-3026.2016.10.002

Abstract ( 753 )

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Distributed generations (DGs) can be used for the power quality enhancement of microgrids. However， load imbalance power cannot be shared accurately among the DGs by using the conventional droop control method for considering the mismatched line impedance. To solve this problem， a novel distributed negative-sequence power sharing method was proposed based on both consensus and adaptive virtual impedance. The negative sequence virtual impedance of each DG was used by this method to achieve accurate negative-sequence power sharing. A multi-agent consistency algorithm was designed to adjust adaptively the negative-sequence virtual impedance， to eliminate the imbalance power sharing error among the DGs， and to implement accurately asymmetric power sharing. The simulation results verified the correctness and validity of the proposed method.

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Forecasting by Interval Type-2 Fuzzy Logic System Optimized with QPSO Algorithm

CHEN Yang， WANG Da-zhi， NING Wu

2016, 37 (10): 1379-1383. DOI: 10.12068/j.issn.1005-3026.2016.10.003

Abstract ( 757 )

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A kind of interval type-2 fuzzy logic system was designed to investigate forecasting problems based on the historical data. In the process of designing the interval type-2 fuzzy logic system， the antecedent， consequent and input measurement primary membership functions of interval type-2 fuzzy sets were all Gaussian type-2 membership functions with uncertain standard deviation. The quantum particle swarm optimization algorithm was used to tune the parameters of the designed interval type-2 fuzzy logic system. Part of the load competition data of European network on intelligent technologies and the price data of West Texas Intermediate crude oil were used to test the proposed fuzzy logic system forecasting method. Comprehensive evaluation error sum was defined as the forecasting performance index of fuzzy logic system. Simulation studies showed that the proposed interval type-2 fuzzy logic system forecasting methods outperform their corresponding type-1 fuzzy logic system on convergence and stability.

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Feasibility Experiment of Respiratory Signal Measurement Based on Magnetic Induction

YANG Dan， QIAO Hong-yu， XU Bin， WANG Xu

2016, 37 (10): 1383-1387. DOI: 10.12068/j.issn.1005-3026.2016.10.004

Abstract ( 628 )

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According to the principle of measuring bioelectrical impedance changes based on magnetic induction， a method was proposed to test the respiratory signal by measuring the change of conductivity in chest. Supposing the thorax as a uniform conductivity sphere， a measuring respiratory signal theoretical model was developed based on the motion characteristics. Some simulations were implemented to analyze the relationship between the thoracic impedance and volume variation， as well as the effect of sensor coil radius on the measurement results. At last， the testing experiments was carried out to discuss the effects of the coil sensor parameters， the conductivity and volume of the NaCl liquid， measuring distance and respiration motion on the measurement circuit. The results showed that the respiratory signal measurement based on magnetic induction will be one of the effective solutions for non-contact， long-term respiratory signal detection and has further research value.

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Primary Value Oriented Class Label Characteristic Analysis

ZHANG Ming-wei， ZHANG Xiao-xu， LIU Ying， HAN Chun-yan

2016, 37 (10): 1388-1392. DOI: 10.12068/j.issn.1005-3026.2016.10.005

Abstract ( 726 )

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A primary value oriented class label characteristic analyzing approach was proposed to extract the essential characteristics of one class label distinguishing with the others. In addition， the interpretability of label datasets could also be improved by this proposed method. Firstly， an intuitive primary value oriented class label characteristic model was built. Then， the corresponding class label characteristic extracting algorithm was designed. Finally， a classification algorithm was presented based on class label characteristic analysis. Experimental results demonstrated that the class label characteristic model can describe the characteristics of each class label for label datasets intuitively and effectively， and the given class label characteristic extracting algorithm has high execution performance. What’s more， the proposed classification algorithm has relatively high accuracy for datasets with fewer class labels.

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Robustness of Interdependent Networks Under Grey Information Attacking

ZHU Qian， WANG Yi-fan， ZHU Zhi-liang， REN Tao

2016, 37 (10): 1393-1397. DOI: 10.12068/j.issn.1005-3026.2016.10.006

Abstract ( 680 )

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The robustness of interdependent networks was researched under grey information attacking， in which the associated data-packet transport problem was discussed. A cascading failure model was established due to the traffic overload. The accuracy of the attacking information was controlled by using tunable parameter. The random failure and intentional attack were the two extreme situations of the proposed model. The robustness of the interdependent networks was studied under different network types and different coupling preferences. The simulation results verified that the robustness of interdependent networks can be intensified by decreasing the precision of attacking information， and there exists a critical phenomenon for the accuracy of the attacking information.

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Temperature Control of Online Heating Strip on Hydraulic Tension Experimental Warm Rolling Mill

SUN Tao， LI Jian-ping， WANG Gui-qiao， WU Zhi-qiang

2016, 37 (10): 1398-1402. DOI: 10.12068/j.issn.1005-3026.2016.10.007

Abstract ( 802 )

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The method of resistance heating was used to heat the workpiece online by applying low voltage and large current. The double loop heating devices and contact-type thermometers were designed to ensure the measurement accuracy and temperature uniformity of the thin plate. The temperature controller adopted the way of combining feedforward and feedback controllers and the setting value of the temperature controller was summed output from the two controllers， in which the feedforward controller was designed on the basis of the heat balance equation of the resistance heating sheet and the PID controller was used as the feedback controller. The results in practice showed that the technology could meet the requirements of heating rate and temperature-controlled precision， and the temperature uniformity was improved by continuous heating in the rolling process.

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Preferential Nucleation Model at Triple Junction and Its Dynamic Recrystallization Simulation

GUAN Xiao-jun， FU Jie

2016, 37 (10): 1403-1406. DOI: 10.12068/j.issn.1005-3026.2016.10.008

Abstract ( 889 )

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In order to perform preferential nucleation at triple junction during dynamic recrystallization (DRX)， a method of identifying the cell existed at triple junction and a preferential nucleation model at triple junction were proposed on the basis of the Moore neighbor of cellular automata. The rationality and application of the model were proved by simulating the DRX process of HPS485wf steel. The results showed that the proposed method and model have the ability to simulate the DRX more effectively. Compared with those from the traditional models， the results from the present model don’t only maintain the evolution of multiple rounds， microstructural feature， the “S-type” curve between area fraction and strain， the simulated flow stress with an accuracy of 0.1% in the process of DRX， and also reveal the preferential nucleation at triple junction， which would provide a more realistic DRX nucleation.

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Effect of MgO on Compressive Strength of Reduced Iron Ore Pellet

GAO Qiang-jian， WEI Guo， JIANG Xin， SHEN Feng-man

2016, 37 (10): 1407-1410. DOI: 10.12068/j.issn.1005-3026.2016.10.009

Abstract ( 721 )

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The effect of MgO on compressive strength of the reduced iron ore pellets was investigated in a lab condition. The experimental results showed that with increasing the mass fraction of MgO-bearing flux from 0 to 2.0%， the compressive strength of the reduced pellets increases. In the meantime， the pore size and porosity of the reduced pellets increase as well. However， compared with that of the non-MgO-bearing pellets (i.e.，the mass fraction of MgO-bearing flux is 0)， the increasing magnitude of the pore size and porosity of the MgO-bearing pellets (the mass fraction of MgO-bearing flux is 2.0%) becomes relatively less and the distribution of pore size is relatively closer before and after reduction. It is found that the reduction swelling is a main factor for governing the compressive strength of the reduced pellets and the reduction compressive strength (RCS) is higher with a lower reduction swelling index(RSI).

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Purifying Scandium Chloride Solution by Ion Exchange

LI Qing-gang ， LI Zhao-yang， SUN Pan， ZHANG Gui-qing

2016, 37 (10): 1410-1414. DOI: 10.12068/j.issn.1005-3026.2016.10.010

Abstract ( 685 )

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The effect of the strong acid styrene type cation exchange resin on deep purification of scandium chloride solution was studied under the different pH value， contact time and the complexant of EDTA. The results showed that when the pH value is 2 and contact time is 3 hours， the resin has great advantage on adsorbing Sc³⁺， Al³⁺ and Fe³⁺， whereas the adsorption performance of Zr⁴⁺， Si⁴⁺ and Ti⁴⁺ is poor. Therefore， the separation between Sc³⁺and Zr⁴⁺，Si⁴⁺，Ti⁴⁺ can be achieved. Adding the complexant of EDTA to complex Sc³⁺ and the ascorbic acid to reduce Fe³⁺ to Fe²⁺， Fe²⁺ and Al³⁺ instead of Sc³⁺ can be absorbed on resin. Through the two-stepped ion exchange process， the removal rate of Fe， Ti， Al， Ca， Zr， Si in scandium chloride solution can be 93.3%， 100%， 99.80%， 98.22%， 99.63% and 100%， respectively.

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Backstepping Sliding Mode Active Disturbance Rejection Control of Quadrotor Attitude and Its Stability

DOU Jing-xin， KONG Xiang-xi， WEN Bang-chun

2016, 37 (10): 1415-1420. DOI: 10.12068/j.issn.1005-3026.2016.10.011

Abstract ( 868 )

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In order to solve the problem of attitude control in quadrotor unmanned aerial vehicle (UAV)， an attitude controller based on backstepping sliding mode active disturbance rejection control (ADRC) was developed. The dynamic model of quadrotor UAV was introduced， and an attitude control scheme based on backstepping sliding mode ADRC algorithm was established. The proposed control scheme mainly includes extended state observer (ESO) and backstepping sliding mode controller based on the Lyapunov stability criterion. The stability analysis showed that the control system is asymptotically stable by appropriately adjusting control parameters. The simulation results indicated that the proposed control scheme has better anti-disturbance performance， adaptivity and robustness than the traditional ADRC. The system has good dynamic performance， steady state performance， and is more effective for attitude control of quadrotor.

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Evaluation Method of Single-Frequency Excitation Capability for Piezoelectric Ceramic Exciter

LI Hui， XUE Peng-cheng， SUN Wei， WEN Bang-chun

2016, 37 (10): 1421-1425. DOI: 10.12068/j.issn.1005-3026.2016.10.012

Abstract ( 777 )

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The linearity index was proposed for evaluating piezoelectric ceramic excitation signal， and experiment was carried out to study a PZT ceramics based on self-designed piezoceramic excitation feedback system. After analyzing the influence factors and law of excitation force， an evaluation method of single-frequency excitation capability was proposed. Evaluation equation was established based on the experimental data， and confidence interval in frequency domain of single-frequency excitation was obtained to make good use of piezoelectric ceramic exciter during the high order vibration test of thin-walled structures. The overall characteristics of the piezoelectric ceramic single-frequency excitation showed that high level excitation capability can be realized under the smaller single-frequency condition， while the low level excitation capability can only be realized under the larger single-frequency condition.

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Fatigue Reliability-Based Sensitivity Design of Planet Gear for Shearer Rocker Arm System

ZHANG Yi-min， WANG Ting， HUANG Jing

2016, 37 (10): 1426-1431. DOI: 10.12068/j.issn.1005-3026.2016.10.013

Abstract ( 634 )

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As the planet gears structure of shearer rocker arm system is very complicated， a finite element model was built using the lumped-mass parameter method， and the dynamic contact stress of the planet gear and sun gear was analyzed to determine its failure mode. Considering the randomness of structural dimension for the planet gear and sun gear， a relational expression between the fatigue life and random parameters was obtained by using the nonlinear mapping function of BP neural network. The MPPPM was applied to the reliability design. The effect of the parameters’ mean and variance on the structure reliability was achieved by the planet gear and sun gear reliability-based sensitivity design.The simulation experiment using the Monte-Carlo showed the correctness of the as-proposed method， and provided a theoretical reference for the reliability-based sensitivity design of the planet gear and sun gear.

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Disjoint Probability of Transmission Chain in Engine Valve Train

YANG Zhou， YANG Hui-da， ZHANG Yi-min

2016, 37 (10): 1432-1436. DOI: 10.12068/j.issn.1005-3026.2016.10.014

Abstract ( 500 )

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Based on the research of certain transmission chain in gas engine valve train， a probabilistic reliability mathematical model of the disconnection of valve train was established with the method of the stochastic perturbation and probabilistic reliability. A transmission chain disjointed reliability analysis method was proposed when the valve mechanism random variables belong to normal distribution. The disjoint probabilities in different sensorimotor stage and different speed were obtained by numerical examples. The disjoint probability increases with the increase of speed， which is consistent with actual situation， and shows the correctness of the as-proposed method. A solution was proposed to reduce the disjoint probability by analyzing the reasons for disconnection， which provide a theoretical basis to improve the follow-up reliability design about engine valve transmission chain.

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Effect of Spiral Groove Depth of Compound Molecular Pump’s Drag Stage on Compression Ratio

WANG Xiao-dong， ZHANG Lei， BA De-chun， TAO Ji-zhong

2016, 37 (10): 1437-1440. DOI: 10.12068/j.issn.1005-3026.2016.10.015

Abstract ( 609 )

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A theoretical model for describing the pumping performance of compound molecular pump’s drag stage was established. According to the theoretical model， the relationship between the depth of drag stage’s spiral groove and compression ratio was studied under different spiral angles， rotor-stator clearances， rotor speeds and gas flows. The results showed that compression ratio firstly increases and then decreases with the decrease of spiral groove’s depth. There exists the optimal groove depth， which result in the maximum compression ratio of drag stage. The spiral angles have little effect on the optimal groove depth which decreases with the decrease of the rotor-stator clearances， and increases with the increase of the rotor speed. The optimal groove depth is smaller when the gas flow is viscous.

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Hammer Structure of Liquid-Jet Hammer Based on Ls-dyna

WU Dong-yu， PENG Jian-ming， YIN Kun， ZHANG Xin-xin

2016, 37 (10): 1441-1445. DOI: 10.12068/j.issn.1005-3026.2016.10.016

Abstract ( 807 )

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A “hammer-bit-rock” impacting model was established based on the methods of the Ls-dyna explicit nonlinear kinetic simulation， and the geometrical parameters of hammer in liquid-jet hammer were studied. The effects of hammer length and diameter on energy transfer for different rocks were studied with constant mass and impact speed of hammer. The strength analysis was also made to investigate the optimal structure of a hammer. The results showed that the energy absorbed by rock increases with the decrease of the hammer diameter. When the hammer length is the optimal value， the rock can achieve the most impact energy， otherwise the energy absorbed by rock may decrease. The higher the drillability grade of rock and the impact velocity， the less the influence of hammer structure on rock breakage. The maximum stress always appears at the end of the bit and stress concentration will be found on the edge of relatively small area. The design of hammer should take the allowable strength of bit into account.

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Effect of Torsion Precision on Torsion Bar Spring Pre-setting Process

WANG Zhen-feng， DONG Ming-ming， ZHAO Kai， GU Liang

2016, 37 (10): 1446-1450. DOI: 10.12068/j.issn.1005-3026.2016.10.017

Abstract ( 802 )

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In order to study the effect of torsion precision on pre-setting process， the elastic-plastic theory was used to discuss the pre-setting process of torsion bar spring. Then， a mathematical model changing with stress， torque and residual stress was obtained under yield pre-setting and plasticity pre-setting situation. The ABAQUS software was used to simulate torsion bar spring with different models and pre-setting situations， and the effect of pre-setting precision on torsion bar spring was analyzed. The results showed that the effect of torsion bar spring pre-setting process in the range of torsion error on pre-setting is less than 5%. The test data not only validates correctness of the finite element model， but shows that torsion bar spring with no more than ±1° pre-setting error can be seen approximately equivalent. The results provide a theoretical reference for improving the process of torsion bar spring pre-setting.

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Estimating Net Primary Productivity Using Chinese GF-1 Remote Sensing Data for Regional Grassland

BAO Ni-sha， WU Li-xin， YE Bao-ying， ZHAO Fei-fei

2016, 37 (10): 1450-1454. DOI: 10.12068/j.issn.1005-3026.2016.10.018

Abstract ( 905 )

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The ability of net primary production (NPP) was estimated by using the Chinese GF-1 remote sensing data. The specified land surface parameters such as vegetation indices， light efficiency and water indices were modified to establish Carnegie-Ames-Stanford approach (CASA) model for NPP modeling by using the Chinese GF-1 satellite data. The field observation data was used to valid the accuracy of simulated NPP from CASA model. There is a good correlation between the simulated NPP and field observed NPP with correlation coefficient of 0.94， and RMSE is 20.59gC/(m²·a). Furthermore， the NPP results were compared with similar study over semi-arid grassland zone. The results showed that the CASA model performs well at regional scale grassland monitoring. The Chinese satellite data has potential to be further applied on the semi-arid grassland， particular on coal mine environment monitoring over this region.

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Process Mineralogy of Sishanling Iron Ore in Benxi， Liaoning Province

YUAN Shuai， LIU Jie， LI Yan-jun， WANG Yue

2016, 37 (10): 1455-1459. DOI: 10.12068/j.issn.1005-3026.2016.10.019

Abstract ( 890 )

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The chemical composition， mineral composition， dissemination characteristics and grain size composition of Sishanling iron ore in Beixi City， Liaoning were investigated through chemical analysis， XRD， optical microscope， electron microprobe and MLA. The results showed that the iron minerals mainly occur in the form of magnetite and hematite， and the primary gangue minerals are quartz and iron-containing dolomite. Magnetite is replaced by hematite with closely complex and intergrowth relation， and the euhedral grain like iron minerals aggregates are irregularly distributed in quartz or dolomite. The disseminated grain size of magnetite is fine. The results may provide a foundation for the rational development and utilization the iron ore resource.

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Integrated Optimization Model of Multi-period Open-Pit Mine Production Scheduling

SUN Xiao-yu， DENG Peng-hong， ZHAO Ming

2016, 37 (10): 1460-1464. DOI: 10.12068/j.issn.1005-3026.2016.10.020

Abstract ( 684 )

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To solve the integrative optimization of multi-period plans in the applications of open pit production only focused on single-period or multi-period optimization with mathematical optimization methods， a 0-1 integer programming model for the integrated optimization was proposed on the basis of previous works of 0-1 integer programming models for “before and after” periods and for “large and small” periods. The corresponding improvement measures were put forward for low computing speed. The model realizes the integrative optimization of multi-period plan， avoids the potential danger of no solution to the discrete optimization， and also guarantees the computational speed and accuracy. The model can be used to verify upper plan with lower plan and to derive upper plan from lower plan， and shows a better adaptability and versatility.

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DNA Sequence Assembly of Paenibacillus Shenyangensis

FU Li-li， JIANG Bin-hui， HU Xiao-min

2016, 37 (10): 1465-1468. DOI: 10.12068/j.issn.1005-3026.2016.10.021

Abstract ( 611 )

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On the basis of existing sequencing data， three sequence assembling programs were utilized to assemble the genome sequence of Paenibacillus Shenyangensis. The assembly data of DNA sequence were analyzed and compared with different software in their optimal parameters， and were compared with genes of the other species of the Paenibacillus in the NCBI database.The results showed that SOAPdenovo is the most appropriate assemble software. When k-mer is 23， the total genome length and N50 are 5501467 and 293864bp， respectively. 4393 of the total 4800 genes are successfully matched and annotated.

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Field Test on Steel Pipe Jacking by STS Method

LI Shen-gang， HAN Jian-yong， SHI Jian-jun， ZHAO Wen

2016, 37 (10): 1469-1473. DOI: 10.12068/j.issn.1005-3026.2016.10.022

Abstract ( 882 )

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STS (steel tube slab) method was used to construct the Olympic sports center station of Shenyang subway line 9. By field test of the steel pipe jacking， the vertical deformation of ground surface and pipe-jacking force were measured， and their changing laws during jacking were analyzed based on the monitoring data. The ground surface deformation laws in the cross section during jacking were summarized and the changing laws of ground surface deformation with the increase of jacking distance， along with the deformation mechanisms were analyzed. The pipe jacking force estimation method based on the filed mornitoring data is suitable for the strata in Shenyang， and could be used as an important reference to the application and development of STS method.

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Interaction Interface of Three Dimensional Entity Model for Goaf

QIN Ya-guang， LUO Zhou-quan， ZHOU Ji-ming， WANG Wei

2016, 37 (10): 1474-1479. DOI: 10.12068/j.issn.1005-3026.2016.10.023

Abstract ( 626 )

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In order to further improve the self-developed functional structure and application of 3D modeling visualized integrated system of goaf and to realize the data of 3D entity model docking between the system and popular 3D mining software， the data interface function for entity model in integrated system was designed. The functional structure of data interface for entity model in integrated system was developed on the basis of analysis on data structure storage rule of 3dm， dat and dtm files. Practical application showed that the interaction and share of goaf’s 3D entity model between integrated system and other 3D mining software could be achieved effectively， and the input and output functions of model data in integrated system are further improved and its application value is enhanced. Meanwhile， the analysis can provide great reference to further study the format of these three files.

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Normal Deformation Behavior of Rock Joint with Deformable Rock Wall

QIAO Li-ping， LI Qi， WANG Zhe-chao， YANG Lei

2016, 37 (10): 1479-1484. DOI: 10.12068/j.issn.1005-3026.2016.10.024

Abstract ( 757 )

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The rock joint normal tests of rock wall with different thickness were conducted without lateral confinements. Based on the test data， the relation between the stiffness and thickness of joint-rock wall system was analyzed， and the stiffness properties of joint-rock wall system with different thickness were obtained. The relations between the normal stiffness and closure of the joint under different confinement manners were analyzed， and a constitutive model for the normal deformation of rock joints with deformable rock walls was proposed. Furthermore， the structural and the material properties of the joint-rock wall system were discussed， and the test technique of the rock joint normal test was deemed important. This study will be helpful for understanding the rock joint normal deformation properties.

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Expansion Characteristics of Salt Rock Under Cyclic Confining Pressure

LI Lin， CHEN Jun-chao， WU Jiao-kun， FAN Jin-yang

2016, 37 (10): 1485-1490. DOI: 10.12068/j.issn.1005-3026.2016.10.025

Abstract ( 586 )

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The rock stress changes periodically during the operation of the salt cavern storage. The dynamic rock cyclic tests on the surrounding rock were carried out， and the influence rules of expansion and damage characteristics of salt rock samples under different axial constant stress and confining pressure cycling cap were analyzed to reveal the influence of stress fluctuations on the stability and tightness of rock. The results showed that volumetric strain curves present a decelerating expansion stage and a steady expansion stage， but there is no significant difference in the cycle’s number of times needed for reaching the stable expansion point of the sample. The smaller the confining pressure cap is or the bigger the constant axial load is， the greater the expansion margin is and the shorter the fatigue life is; the proportion of steady expansion out of uniform expansion is smaller， namely the accelerated expansion points move forward. With the increase of test cycles， the isovolumetric strain ratio becomes smaller and the toughness decreases while the expansion capability increases. The smaller the confining pressure cap is or the bigger the constant axial load is， the faster the loss of toughness capacity is and the stronger the expansion capacity of salt rock is.

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Mechanism and Stress Analysis of Rock Core Discing

MA Tian-hui ， WANG Long ， XU Tao， YU Qun

2016, 37 (10): 1491-1495. DOI: 10.12068/j.issn.1005-3026.2016.10.026

Abstract ( 1474 )

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Numerical simulation method was used to explore the influence of in-situ stress on rock core discing under different stress combinations. The results showed that when the in-situ stress exceeds a certain value， rock core discing occurs. When the radial stress reaches 35MPa， rock core discing occurs， and the radial stress is the main factor that affects rock core discing， while the axial stress only leads to the partial failure on core surface. At the same radial stress， the core discing weakens with the increase of axial stress. The formation process of core discing is mainly dominated by shear failure， accompanied with a little tension failure. Rock core discing is a complex mechanical process.

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Evaluation Method of Shale Brittleness Based on Indoor Experiments

HOU Zhen-kun， YANG Chun-he， WANG Lei， XU Feng

2016, 37 (10): 1496-1501. DOI: 10.12068/j.issn.1005-3026.2016.10.027

Abstract ( 612 )

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Comprehensive brittleness indexes B_d1 and B_d2 including multi-parameters were proposed on the basis of the stress-strain curve. The brittleness characteristics were interpreted through the inflection point of dilatancy (the pre peak curve)， the residual strength (the post peak curve)， and energy analysis (the complete stress-strain curve). Axial and triaxial compression tests were conducted to examine the new indexes corresponding to failure mode. The results showed that the two evaluation indexes can preferably reflect the brittle characteristics of shale. For B_d1， related parameters can be selected freely according to different purpose， which can pay particular attention to any parameters in the process of brittleness evaluation. B_d1 can be better fitted by confining pressure with an exponential function. B_d2 can be used as a comprehensive evaluation index of brittleness evaluation， but B_d2 is not sensitive to high confining pressure. Under the coring angle of 90°， the evaluation indexes of brittleness decrease with the increase of confining pressure， and shale exhibits a tendency from brittle at low confining pressure to ductile at high confining pressure. The evaluation indexes are sensitive to confining pressure under low confining pressure and reduce quickly， and vice versa under high confining pressure.

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Optimal Calculation Mode of Vertical Sand Silo Area Based on Flocculating Sedimentation

WANG Shi， ZHANG Qin-li， WANG Xin-min， LI Shuai

2016, 37 (10): 1501-1506. DOI: 10.12068/j.issn.1005-3026.2016.10.028

Abstract ( 720 )

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In order to explore the optimal calculation mode of vertical sand silo area under the condition of flocculating sedimentation of unclassified tailings， the minimized result error was determined through 3 calculation modes based on the ideal sedimentary condition and the different sedimentary characteristics. Took the case of a lead and zinc ore as an example: the flocculating sedimentation tests of fine unclassified tailings were conducted， then the slurry settlement curves under the best settling condition were obtained by regression analysis. The reliability of calculation modes for vertical sand silo area was analyzed. Results showed that the best flocculent condition is as follows: the relative molecular weight of APAM is 8×10⁶， the volume fraction of feeding slurry is 7.80% and the appropriate unit consumption of flocculants is 17.66g·t^-1. The optimal area of vertical sand silo is 36.06m²， which is 97.04% close to the result based on the Talmage-Ficth graphical method.

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Effect of Abusive Supervision on Knowledge Workers’ Turnover Intention and Its Action Mechanism

ZHANG Lan-xia， WANG Li-xia， CAO Ya-shuang， WANG Chong

2016, 37 (10): 1507-1511. DOI: 10.12068/j.issn.1005-3026.2016.10.029

Abstract ( 613 )

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Based on the social exchange theory and the social identity theory， the effect of abusive supervision on knowledge workers’ turnover intention in China was studied empirically， with the mediating and moderating role of organizational identification and personality characteristics analyzed on a random sample of 320 knowledge workers. The results indicated that abusive supervision is positively related to turnover intention of knowledge workers. Organizational identification plays a part mediation role in the influence process of abusive supervision on turnover intention of knowledge workers. The personality characteristics buffers the effect to some degree. So enterprises should strengthen the institutional and cultural construction to avoid knowledge worker′s turnover generated by reducing the abuse of leaders and enhancing the organizational identification of employees.

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Risk Aversion Inventory Model Based on Maximum Entropy Approach Under Limited Demand Information

QIU Ruo-zhen， YUAN Hong-tao， FENG Qiao

2016, 37 (10): 1512-1516. DOI: 10.12068/j.issn.1005-3026.2016.10.030

Abstract ( 597 )

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A single period inventory model based on the conditional value-at-risk (CVaR) was developed for risk aversion decision-maker. Only considering demand interval， mean and variance information， the maximum entropy approach was used to estimate the demand distribution for both of the two demand uncertainties. The results showed that the decision-maker should adopt the uniform and exponential distribution as the potential demand distribution when only knowing the demand interval， and mean and variance information. On this basis， the CVaR-based inventory strategies and performances were deduced. The simulated results showed that the inventory strategy derived from the estimated distribution by maximum entropy will lead to a certain performance loss， however the loss ratio is very limited. It indicates that the ordering strategy based on the maximum entropy has good robustness.

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Security Analysts Earning Forecasting Behaviors Based on Investor Sentiment

LI Xiao-qing, ZHUANG Xin-tian

2016, 37 (10): 1517-1520. DOI: 10.12068/j.issn.1005-3026.2016.10.031

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The fixed effects model was used to analyze empirically the panel data of Shanghai and Shenzhen stock markets in 2005~2013， and the effect of investor sentiment on earning forecast of security analyst was investigated. The results showed that in the high investor sentiment period， earning forecast is relatively optimistic， the accuracy is higher and the divergence degree is bigger also，which are opposite in the low investor sentiment period. The prediction of security analyst-rational represent is affected not only by enterprise factors in micro-level， but also by the investor sentiment in macro-level. It demonstrates that the profit forecast behavior from the view of behavioral finance.

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