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15 October 2017, Volume 38 Issue 10 Previous Issue    Next Issue
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Information & Control

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Robust Iterative Beamforming Algorithm Based on Uniform Circular Array SONG Xin， WANG Jin-kuan， LIU Wen-min， GAO Jing 2017, 38 (10):  1369-1372.  DOI: 10.12068/j.issn.1005-3026.2017.10.001 Abstract ( 835 )   HTML   PDF (423KB) ( 897 )   The performances of traditional beamformers degrade severely in the presence of signal steering vector mismatches and transformation errors， and the uniform circular array (UCA) does not have the Vandermonde structure， a novel robust iterative beamforming algorithm based on the uniform circular array was proposed. Using phase-mode transformation technique， the virtual correlation matrix was obtained and the steering vector was belong to the certain ellipsoid set. The worst-case performance optimization was used and the cost function of second convex programming was constructed based on UCA. The weight vector has a closed-form solution by the Lagrange multiplier method， in which the diagonal loading factor was derived exactly. The simulation results showed that the proposed algorithm can provide efficient robustness and improve the array output performance. References | Related Articles | Metrics

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Joint Truth Finding on Heterogeneous Data CHEN Chao， SHEN De-rong， KOU Yue， YU Ge 2017, 38 (10):  1373-1377.  DOI: 10.12068/j.issn.1005-3026.2017.10.002 Abstract ( 861 )   HTML   PDF (387KB) ( 877 )   The value of an entity attribute on the web is usually provided by multiple data sources， but the values provided by them are not always the same， which affects the effective integration of data， so it is necessary to find out the true value among these given values. The existing truth finder algorithms mainly focus on the single type data kind， so a distance-based truth finding algorithm was proposed by considering heterogeneous data jointly. Firstly， for a specific data item， the data item vectors were calculated on the basis of the distance between the claimed value from every source and the truth value. The KMeans algorithm was used to get initial clustering. Then， alternate clustering and trust analysis were iteratively performed， i.e.， within each cluster， confidence of facts and trustworthiness of sources were updated with the idea of optimization and joint heterogeneous data. Each data item vector was recalculated and reclustered， and when each cluster was stable， the iteration would be terminated. The experiment results showed that the proposed algorithm has a higher accuracy for truth finding because of the fine grained partition of source quality and the joint model of heterogeneous data. References | Related Articles | Metrics

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Linear Time-Varying Channel Estimation of OFDM Based on Joint Sparse Model SONG Zu-xun， HU Jian-sheng， ZHANG Qian 2017, 38 (10):  1377-1382.  DOI: 10.12068/j.issn.1005-3026.2017.10.003 Abstract ( 787 )   HTML   PDF (830KB) ( 691 )   In order to improve the performance of linear time-varying channel estimation in OFDM system， a channel estimation method based on the joint sparse model was presented by using the temporal sparsity and correlation of channel tap. Firstly， the channel estimation of continuous OFDM system periods was converted to a joint sparse reconstruction model. Secondly， the group pilot based on the minimization of the measurement matrix coherence was used to deal with the subcarrier interference and ensure the performance of the sparse reconstruction algorithm. Finally， a group pilot pattern optimization algorithm based on the parallel tree loop structure was also proposed. Compared with the traditional linear time-varying channel estimation method and the channel estimation method based on the joint sparse model， the proposed method needs less pilot frequency，has much better channel estimation performance， and is convenient for application. References | Related Articles | Metrics

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Segmentation Method of Base of Left Ventricle in Cardiac Magnetic Resonance Images XU Li-sheng， GUO Zeng-zhi， TAN Wen-jun， WANG Lu 2017, 38 (10):  1383-1387.  DOI: 10.12068/j.issn.1005-3026.2017.10.004 Abstract ( 747 )   HTML   PDF (855KB) ( 941 )   A novel method was proposed for segmenting the base of the left ventricle in cardiac magnetic resonance imaging (MRI) images based on local intensity clustering (LIC) model and watershed algorithm. First， the cardiac MRI images were segmented by LIC model to detect the tissues and organs. Then， the connected tissues and organs were separated by using watershed algorithm to make up for the missing edges. The seed points were artificially selected to carry growing for the preliminary extraction of left ventricle. Finally， whether the preliminary extraction of the left ventricle contains the aorta will be judged by priori knowledge of the shape features of the left ventricle， if the preliminary extraction of the left ventricle contain the aorta， the effect of the missing edge caused by the aorta will be removed to get an accurate segmentation result of the base of left ventricular. Experimental results demonstrated that the proposed method can effectively remove the effect of weak edges and edge leakage of the base of the left ventricle in MRI images to obtain an accurate segmentation result of the base of left ventricular. References | Related Articles | Metrics

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RBF Neural Network Control of Live Operation Robot Manipulator for High Voltage Transmission Line JIANG Wei， WU Gong-ping， CAO Qi， YANG Song 2017, 38 (10):  1388-1394.  DOI: 10.12068/j.issn.1005-3026.2017.10.005 Abstract ( 743 )   HTML   PDF (786KB) ( 793 )   Due to the shortage of manual tension clamp drainage board bolt tighten for high voltage transmission line， such as low operation efficiency， labor-intensive， high-altitude and high risk， an bolt tighten live operation robot was designed which had double arms and double manipulators. The key issues of bolt tighten was analyzed theoretically during the entire operation process， and a RBF neural network model of bolt tighten process control was established. The robot bolt tighten process was abstracted into nonlinear approximation， and a robot bolt tighten status monitoring control method based on the RBF neural network was proposed. Finally the live operation result showed that the connection reliability of the robot tighten bolts is greatly enhanced by using the proposed method that has strong engineering practicability， and the operation efficiency ，operation safety and operation operability are all improved. References | Related Articles | Metrics

Materials & Metallurgy

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Development of Universal Thermodynamic Model for Carbo-Nitride Precipitation YANG Yong， WANG Zhao-dong， JIA Tao， LI Yan-mei 2017, 38 (10):  1394-1398.  DOI: 10.12068/j.issn.1005-3026.2017.10.006 Abstract ( 733 )   HTML   PDF (624KB) ( 708 )   Based on the regular solution approximation， the two sub-lattice model and dissolution and precipitation theory， a universal thermodynamic model for carbo-nitride precipitation was established. The model was used to calculate the thermodynamic equilibrium information including matrix composition， composition and volume fraction of precipitation between sub-stoichiometric or stoichiometric precipitation and matrix of the 0.17C-0.023Nb-0.012Ti-0.004N at different temperatures. The results showed that the solubility of sub-stoichiometric precipitation is bigger than that of stoichiometric precipitation， and the volume fraction of the former is less than the latter one at the same temperature. With the decrease of the temperature， the precipitation is gradually changing from titanium nitride to complex precipitation which is rich in niobium and carbon， and the volume fraction differences in different precipitations also decrease gradually. References | Related Articles | Metrics

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Experimental Studies on Heat Transfer of Ultra Fast Cooling for Steel Plate FU Tian-liang， DENG Xiang-tao， HAN Jun，WANG Zhao-dong 2017, 38 (10):  1399-1404.  DOI: 10.12068/j.issn.1005-3026.2017.10.007 Abstract ( 659 )   HTML   PDF (1207KB) ( 754 )   Spray jet cooling method was used to study the surface jet flow structure， heat transfer zone and plate temperature drop during the ultra fast cooling process for a steel plate with the thickness of 10mm， and the effects of inclination jet on heat flux and cooling rate of the plate surface were also analyzed， where the spray inclination angle was ranging from 0° to 60°. The results showed that the spray inclination angle can affect the heat transfer type of plate surface and heat flux distribution by changing plate surface stagnation zone and transverse flow zone’s area， water flow density， flow state and flow velocity， so that it will further influence the cooling rate of ultra fast cooling greatly. The average cooling rate and heat flux density reach the maximum values with 146.5℃/s and 2.75MW/m2， when the spray inclination angle is 30°. References | Related Articles | Metrics

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Research and Application for Medium Steel Plate-Slab Design System ZHENG Zhong， HU Wan-zhe， LONG Jian-yu， GAO Xiao-qiang 2017, 38 (10):  1405-1410.  DOI: 10.12068/j.issn.1005-3026.2017.10.008 Abstract ( 836 )   HTML   PDF (963KB) ( 822 )   On the basis of the analysis of the production and design process， a medium steel plate-slab design system (MSPSDS) was built by employing the layered modular design method. The system architecture of MSPSDS was developed by separating the functional moduli for different types of problems including application maintenance， design management and data supporting. MSPSDS focuses on solving steel plate-slab integrated optimal design problems under one and two dimensions. A hybrid solving method was proposed by combining optimization techniques and heuristic rules for minimizing the amount of surplus material and maximizing the rolling yield. The test experiments conducted by using the data instance from a steel plant showed that MSPSDS significantly outperforms manual design both in terms of quality and efficiency. References | Related Articles | Metrics

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Dynamic Mesh Simulation of Fluid Flow， Heat Transfer and Interface Tracking in TIG Welding Process LI Lin-min， LI Bao-kuan， LIU Li-chao， CAO Xia 2017, 38 (10):  1411-1416.  DOI: 10.12068/j.issn.1005-3026.2017.10.009 Abstract ( 753 )   HTML   PDF (2260KB) ( 817 )   Based on the magnetohydrodynamic (MHD) model， the dynamic mesh method (DMM) was used to track arc-molten pool interface， and a mathematical model for coupled fluid flow， heat transfer， solidification/melting and dynamic interface tracking during TIG welding process was established. Firstly， a free-burning arc was simulated to obtain the accurate arc parameters， such as the speed， temperature and pressure. Then， the four driving forces of electromagnetic， thermal buoyancy， drag and Marangoni were validated respectively. Considering the arc-molten pool interaction and tracking the interface from pressure balance， the TIG welding process for the 304 stainless steel was simulated and the depression in the pool center and the lifting on the pool periphery caused by plasma shock were obtained. It is shown that the proposed model can simulate the arc-pool interface and molten pool shape more accurately in comparison with the experimental data. References | Related Articles | Metrics

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Study on Heat Transfer Coefficient and Numerical Simulation of Planar Solidification Casting SHAO Bo， QIN Ke， ZHANG Hai-tao， CUI Jian-zhong 2017, 38 (10):  1416-1420.  DOI: 10.12068/j.issn.1005-3026.2017.10.010 Abstract ( 786 )   HTML   PDF (1154KB) ( 837 )   2D mathematical models of spray cooling and planar solidification casting were established. Using the temperature data measuring from 1070 aluminum alloy ingot， the relationships between the cooling surface temperature and heat transfer coefficient (HTC) under different cooling water pressures was derived reversely， which was used to verify the model of planar solidification casting. The results showed that the HTC firstly increases and then decreases with the decrease of the cooling surface temperature， and reaches the peak at about 400K. The HTC peak value and its corresponding temperature increase with the cooling water pressure. The casting experiment results showed that the solidification front is macroscopically planar and the cooling rate of the ingot is uniformly distributed during the solidification. The simulation results well agree with the experimental results， which prove the capability of the model of planar solidification casting. References | Related Articles | Metrics

Mechanical Engineering

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Vehicle Angular Variation Control Based on State Space Model NING Dan-feng， CHEN Wan-chun， YANG Ming-hui， SUN Yan-jie 2017, 38 (10):  1421-1425.  DOI: 10.12068/j.issn.1005-3026.2017.10.011 Abstract ( 623 )   HTML   PDF (2971KB) ( 706 )   Minimized angular variation stage-by-stage method (MAVSM) and minimized the final angle variation method (MFAVM) were proposed based on the state space model for vehicle assembly， and compared with the direct assembly method (DAM). The results showed that the angular variation of DAM follows the Rice distribution， and increases with the stage. The MAVSM and MFAVM follow generalized extreme value distribution. MAVSM is not affected by the stage， but the mean and standard deviation of angle variation decrease with the stage and converge at 0 for MFAVM. References | Related Articles | Metrics

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Micro Milling Cutter Breakage Detection Based on Wavelet Singularity and Support Vector Machine LIU Yu， WANG Qian， LIU Kuo， ZHANG Yi-min 2017, 38 (10):  1426-1430.  DOI: 10.12068/j.issn.1005-3026.2017.10.012 Abstract ( 574 )   HTML   PDF (531KB) ( 720 )   A tool breakage detection method was proposed based on the singularity analysis of vibration signal and self-learning support vector machine. The measured vibration signals were decomposed by the continuous wavelet transform， the wavelet modulus maxima (WTMM) and the Lipschitz index (Lips) were calculated. The state of tool breakage was recognized by Lips， and the Lips probability density function was fitted， which obeys the normal distribution. The support vector machine identification model of tool state was established by the parameter optimization of genetic algorithm based on mean value and variance of Lips (also called the optimal model). The tool breakage state was predicted by using this model， of which prediction accuracy increased gradually from 84% to 90%， and the robust of system prediction model was improved. Finally， the effectiveness of this method was verified by the experiments. References | Related Articles | Metrics

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Finite Element Analysis of Knee Joint Cartilage at Turning of Plough Type Ski FU Yan-ming， YU Tian-biao， WANG Xin， WANG Wan-shan 2017, 38 (10):  1431-1435.  DOI: 10.12068/j.issn.1005-3026.2017.10.013 Abstract ( 659 )   HTML   PDF (1895KB) ( 696 )   Two hundred subjects were randomly selected to record their basic information， joint angle and sliding speed， and 181 valid data were analyzed. According to a volunteer′s MR， CT data， a 3D cartilage and bone model of the knee 140° was established. According to the result of kinematic analysis and knee anatomy structure， the load and constraints were defined. The stress concentration position on the knee cartilage was obtained in the Abaqus6.14. The results showed that the slider with large weight or sliding too fast should increase the turning radius in order to reduce the stress of the centripetal force on knee joint cartilage. It is advisable to control the speed of plough type turn within 3m/s. References | Related Articles | Metrics

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Molecular Dynamics Simulating Effect of Rake Angle on Single Crystal Nickel Nanometric Machining ZHU Zong-xiao， GONG Ya-dong， ZHOU Yun-guang， ZHANG Yan-xiang 2017, 38 (10):  1436-1441.  DOI: 10.12068/j.issn.1005-3026.2017.10.014 Abstract ( 622 )   HTML   PDF (1612KB) ( 724 )   Molecular dynamics simulation was used to study the nanometric machining process of single crystal nickel. The change rule of cutting force showed that the violent fluctuation of cutting force at initial stage is closely related to the generation of large stacking faults. The cutting tools with different rake angles were applied to conduct a series of simulations， the results showed that cutting force and the friction coefficient between rake face and chip decrease gradually with the increase of rake angle. The push and overall bending of chip decrease， and the chip height and the perfect FCC atom ratio gradually increase due to the increase of rake angle. The defect atom number decreases， as well as the damage depth of workpiece subsurface. In the process of machining with negative rake angle tool， the subsurface damage of workpiece is more serious， and the stacking fault tetrahedral structure and the LC dislocation are generated in workpiece subsurface. Meanwhile， the number of high temperature atoms decrease with the increase of rake angle， and the temperature distribution of the workpiece radiates from the tool corner to the workpiece. References | Related Articles | Metrics

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Effect of Service on Fracture Mechanical Properties of 7N01 Aluminum Alloy ZHANG Xiao-chen， XIE Li-yang， HU Jie-xin， ZHANG Shi-jian 2017, 38 (10):  1442-1446.  DOI: 10.12068/j.issn.1005-3026.2017.10.015 Abstract ( 962 )   HTML   PDF (1819KB) ( 898 )   The reliability and durability of materials in service are the assessment foundation of the structural safety. Aimed at the 7N01 aluminum alloy experienced a long term service in high speed trains， the fatigue mechanical properties were investigated in laboratorial atmosphere， and the fatigue cracks propagation (FCP) behaviors of materials with/without service were analyzed. The results showed that the experience of service deteriorates the mechanical properties， showing a regular decline trend. The da/dN-ΔK curve in the FCP zone after service showed a turning phenomenon， and a piecewise Paris’ curve fitting method was used to describe the FCP behavior. The results of the fracture surface morphologies showed that the are crack initiation zone， steady growth zone and rapid growth zone of 7N01 alloy after service corresponding to cleavage fracture mode， mixed plastic and cleavage fatigue striation， and mixed intergranular and transgranular fracture， respectively. References | Related Articles | Metrics

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Nonlinear Fractal Model for Static Friction Coefficient Considering Three-Dimensional Topography of Joint Surfaces PAN Wu-jiu， LI Xiao-peng， WANG Xue， LI Mu-yan 2017, 38 (10):  1447-1452.  DOI: 10.12068/j.issn.1005-3026.2017.10.016 Abstract ( 710 )   HTML   PDF (611KB) ( 718 )   Considering three-dimensional topography W-M function of joint surfaces， a nonlinear fractal model for static friction coefficient considering three-dimensional topography of joint surfaces was established. Relations between the static friction coefficient considering three-dimensional topography of joint surfaces and normal load， the fractal dimension， fractal roughness were numerically simulated， as well as the difference between static friction coefficients in the two-dimensional fractal model and three dimensional fractal model. The results showed that the static friction coefficient increases monotonically with the increase of normal load， and decreases monotonically with the increase of topothesy. When D is less than 2.5， the static friction coefficient increases with the increase of fractal dimension; when the D is greater than 2.5， the static friction coefficient decreases with the increase of fractal dimension; the three-dimensional fractal static friction coefficient is smaller than that of the two-dimensional. References | Related Articles | Metrics

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Reliability Analysis for Mechanical System with Correlated Failure Modes TU Hong-mao， SUN Zhi-li， JI Guang-zhen， QIAN Yun-peng 2017, 38 (10):  1453-1458.  DOI: 10.12068/j.issn.1005-3026.2017.10.017 Abstract ( 646 )   HTML   PDF (589KB) ( 833 )   To evaluate the effect of failure mode correlations on the mechanical system reliability， a system reliability analysis method and its implementation procedures were proposed based on FORM approximation. FORM was used to calculate the reliabilities and sensitivities of all the failure modes in the system， and then the failure mode correlation coefficient matrix for determining how they are correlated was obtained. The solving of the system reliability model was converted to the integration of multivariate normal distributions， and the efficient approximation algorithm was used to get reliability degree. The definition of failure mode sensitivity and the corresponding calculation method were proposed based on the numerical difference， as well as the definition of random parameter sensitivity and its calculation method through the composite derivative theorem. The results demonstrated the efficiency of the proposed method for quantifying the mechanical system reliability with failure mode correlations， and also the feasibility for identifying the key failure modes and random parameters. References | Related Articles | Metrics

Resources & Civil Engineering

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Effect of Loading Rate on Fragmentation and Energy Dissipation Characteristics of Sandstone LI Shao-hua， ZHU Wan-cheng， NIU Lei-lei， DAI Feng 2017, 38 (10):  1459-1463.  DOI: 10.12068/j.issn.1005-3026.2017.10.018 Abstract ( 620 )   HTML   PDF (888KB) ( 770 )   In order to study the effects of loading rate of stress wave on rock breaking and energy efficiency， 5 hammers with different radius of curvature were designed by using the nonlinear model of the local deformation in the longitudinal impact surface of the members. Incident stress waves with different loading rates were achieved under different and identical incident energy， and the impact test of red sandstones was conducted. The results showed that the fractal dimension of fragmentation of sandstone specimen increases linearly with the increase of the loading rate of stress wave. The fractal dimension of fragmentation of sandstone specimen increases with the increase of incident energy under the same loading rate. The energy dissipation density increases with the increase of loading rate of incident wave. Under the same loading rate， the greater the incident energy is， the greater the energy dissipation density is. The energy efficiency decreases obviously with the increase of the incident energy under different incident energy. In practice， the best incident wave must be designed considering the factors such as rock breaking and the energy efficiency. References | Related Articles | Metrics

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Risk Evaluation of Break-Dam in Mine Tailings Pond Based on GA-AHP and Cloud-Matter Element Model WANG Xun-hong， GU Xiao-wei， XU Xiao-chuan， WANG Qing 2017, 38 (10):  1464-1467.  DOI: 10.12068/j.issn.1005-3026.2017.10.019 Abstract ( 713 )   HTML   PDF (318KB) ( 1004 )   For the accurate evaluation on risk level of break-dam in mine tailings pond， a GA-AHP and cloud-matter element model was established. The major risk factors on break-dam were identified by using the Delphi method， and the risk evaluation index system of break-dam was established. The index weights of break-dam in mine tailings pond were calculated by using GA-AHP. The evaluation index was classified to establish the risk assessment model based on the GA-AHP and cloud-matter element model. The established model was applied to practical case， and the Matlab software was used to calculate the subordinate degree. The results showed that the risk of break-dam in the mine tailings pond is normal and the evaluation results are consistent with the practice. References | Related Articles | Metrics

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Monitoring Method of Landslide Displacement Field Based on High-Resolution Images and ASIFT Algorithm ZHANG Hui-hui ， LIU Shan-jun ， WANG Ru 2017, 38 (10):  1468-1473.  DOI: 10.12068/j.issn.1005-3026.2017.10.020 Abstract ( 579 )   HTML   PDF (1987KB) ( 781 )   In view of the shortcomings of displacement field of large deformation landslide with SIFT algorithm and high-resolution remote sensing images， a feature matching algorithm with fully affine invariability(ASIFT) was introduced to extract and match features on different phases of high-resolution remote sensing images. The Fushun West Open-Pit Mine was selected as a study area， and the displacement field was analyzed with the ASIFT algorithm. The results showed that compared with the SIFT algorithm， the deficiency of the feature extraction algorithm in affine invariance is compensated， the feature matching points increase and the accuracy of the displacement vector field of the landslide is improved by using ASIFT algorithm. The ASIFT algorithm is more suitable for monitoring the displacement field of large landslide with higher degree of automation and lower cost. References | Related Articles | Metrics

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Coal Classification Based on Visible and Near-Infrared Spectrum SONG Liang， LIU Shan-jun， MAO Ya-chun， LI Tian-zi 2017, 38 (10):  1473-1476.  DOI: 10.12068/j.issn.1005-3026.2017.10.021 Abstract ( 819 )   HTML   PDF (398KB) ( 791 )   The portable spectrometer SVC HR-1024 was used to carry out spectral tests on the 92 bituminite and 58 lignite coal samples from various coal mines. By comparing their spectral curves， the differences between bituminite and lignite samples can be observed visibly in spectral characteristics. The reflectance of lignite samples is obviously higher than that of bituminite samples， as well as the slope of spectral curves. On the basis of spectral characteristics analysis， the MAO model algorithm， random forests， BP neural networks and ELM-neural network were selected for the classification of bituminite and lignite samples. The results indicated that the MAO model algorithm and random forest algorithm outperform other algorithms on classification. For large-area and rapid recognition by remote sensing， the MAO model algorithm has a great advantage in the classification time. While the random forest algorithm can be used for classification in small mining areas. References | Related Articles | Metrics

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Microbial Relative Abundance of Major Oil-Shale Mines in China by FISH Detection WANG Wen-xing， JIANG Shao-yan， XUE Xiang-xin， HOU Xiao-jiao 2017, 38 (10):  1477-1481.  DOI: 10.12068/j.issn.1005-3026.2017.10.022 Abstract ( 689 )   HTML   PDF (2136KB) ( 658 )   The relative abundances of bacteria and archaea in major oil-shale mines (Fushun Mine in Liaoning， Huadian Mine in Jilin and Maoming Mine in Guangdong) of China were investigated by fluorescence in situ hybridization (FISH) method， and three types of samples were collected from each mine， including sandy soil， freshly mined oil-shale and weathered oil-shale or underground sandstone. The optimal hybridization conditions of TRIzol and lysozyme were beneficial to increasing the hybridization rate when the hybridization temperature was 46℃， the hybridization time was 2.5h， and the volume fraction of deionized formamide was 20%.In all samples， the relative abundances of bacteria and archaea are above 50% and below 5%， respectively， and the relative abundances of bacteria and archaea in the freshly mined oil-shale are the highest. The relative abundances of bacteria and archaea are different between any two mines: bacterial relative abundance in Huadian mine is the highest， followed by Maoming mine and Fushun Mine， but archaeal relative abundances are just the reverse. References | Related Articles | Metrics

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Warning Technology for Air Nuclear Pollution Diffusion of Nuclear Power Plant SHEN Yue， HU Xiao-min ， MA Yun-feng， CHEN Guo-ping 2017, 38 (10):  1482-1486.  DOI: 10.12068/j.issn.1005-3026.2017.10.023 Abstract ( 627 )   HTML   PDF (937KB) ( 833 )   Based on environmental protection automatic command system (C4ISRE)， the early warning technology for air nuclear pollution diffusion of the nuclear power plant was proposed. Firstly， an integration simulation environment of sea， land， sky and space for Hong Yanhe Nuclear Power Plant was constructed. Secondly， nuclear pollution diffusion scenario was set up and the HYSPLIT4.9 model was drove by meteorological data according to the scenario. Then， the atmospheric nuclear pollutant transport characteristics were simulated， and the early warning emergency response times for key areas were simulated and deduced. The deduction results showed that nuclear pollution air mass spreads into the waste storage tank factory building of conventional island after 71.885s， the airspace of heat engine repair shop and warehouse after 79.306s， the airspace of wastewater treatment plant and garage after 91.596s， the airspace of the boundary of the plant boundary and sea after 132.267s， plume boundary of emergency region 5km after 655.337s， the airspace of Wong Tung Village after 712s， plume boundary of emergency region 10km after 1240.535s， the airspace of Changxing Island town after 2527.945s， and plume boundary of emergency region 30km after 3468.65s. References | Related Articles | Metrics

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Stage Blasting Technology of Large and Thick Steeply Inclined Orebody ZHAI Hui-chao， REN Feng-yu， NAN Shi-qing 2017, 38 (10):  1486-1490.  DOI: 10.12068/j.issn.1005-3026.2017.10.024 Abstract ( 711 )   HTML   PDF (1432KB) ( 693 )   Aiming at the safety problem of Sijiaying southern district large-scale mining district， a lateral drilling blasting scheme including formed trench by the fan hole and lateral caving by the vertical deep hole was proposed， which has characteristics of a small amount of engineering， high degree of mechanization and simple management， etc. In addition， the rationality and shock absorption of large scale blasting initiation order and the non-destructive effect of blasting on rock and filling body were verified through dynamic simulation on the plastic zone， monitoring vibration velocity and stress field by FLAC3D. Meanwhile， the construction technology of cutting patio using VCR method， adopting center and cross diamond pattern for designing the hole， and using 5 sections of initiation among holes were studied to ensure the formation of blasting free space. References | Related Articles | Metrics

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Heat Transfer Process of Ethanol Pool Fire Under Different Ventilation Conditions in Tunnel ZHANG Pei-hong， DONG Jia-bin， MENG Qi， ZHANG Yun-li 2017, 38 (10):  1491-1495.  DOI: 10.12068/j.issn.1005-3026.2017.10.025 Abstract ( 657 )   HTML   PDF (849KB) ( 679 )   To analyze the effect of various ventilation modes on heat transfer process of pool fire， fire tests in 0.5m diameter ethanol pool were conducted in the tunnel model. Mass loss rate of fire source， fire temperature field， radiation and convection heat flux of flame were measured and analyzed. The results showed that 0.5m/s longitudinal smoke discharge plays a negative role in the control of fire heat transfer process， the radiant heat flux of persistent flame at the developed stage of fire is 30% bigger than that under natural ventilation condition. Under 0.8，1m/s longitudinal smoke discharge conditions， the radiant heat flux of the persistent flame and the upper smoke layer temperature decreased significantly at the developed stage of fire. 0.5m/s top smoke discharge mode significantly reduced the radiant heat flux of persistent flame， in which fire precedes into the strong stage at the latest and into the decay stage earlier. 0.5m/s top smoke discharge is the most premium ventilation mode. References | Related Articles | Metrics

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Effect of H2O on Propagation of Laminar Syngas Flames SHANG Rong-xue， LI Gang， ZHANG Pei-hong 2017, 38 (10):  1496-1500.  DOI: 10.12068/j.issn.1005-3026.2017.10.026 Abstract ( 636 )   HTML   PDF (583KB) ( 724 )   The laminar flame speeds of syngas/air mixtures with H2O dilution in the fuels were numerically studied at 400K using Davis-Mech. Based on the calculated sensitivities of mass burning rate of mixtures with various H2O dilution ratios， the thermal， direct-reaction and third-body effects on the laminar flame speed of diluted mixtures were also carried out for an insightful understanding of the dilution effect of H2O. The results showed that when the volume fraction of H2 is larger than 25%， the laminar flame speed， adiabatic flame temperature and the mole fractions of the crucial radical of mixtures decrease significantly with the increase of dilution ration. The total dilution effect of H2O was dominated by the thermal effect. When the equivalence ratio of mixture was small， the direct reaction effect caused by H2O on the laminar flame speed was changed from promotion into inhibition with increasing volume fraction of H2. When the amount of H2O was limited， the third-body effect on the laminar flame speed experiences a significant inhibition-promotion-inhibiting action. References | Related Articles | Metrics

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Intrusive Characters of Damage Rock by Shock Disturbance LOU Lei， WU Wan-rong， WANG Song-lai， LIANG Xiang-jing 2017, 38 (10):  1501-1506.  DOI: 10.12068/j.issn.1005-3026.2017.10.027 Abstract ( 583 )   HTML   PDF (1531KB) ( 660 )   In order to improve the drilling efficiency and reduce tools wear， a new rock fragmentation method of shock disturbance was put forward. Based on the theory of Walsh， a crack model of the damage rock around the induced hole was established， the intrusive coefficient equations and intrusive resistance equations of the cone bit were deduced. The influences of crack density， the disturbance frequency on the elastic modulus， the rock crushing volume and the intrusive resistance were analyzed. Experimental results showed that the effective elastic modulus of rock decreases with the increase of crack density. Under the certain intrusion load， the depth of the penetration and the rock crushing volume increase continually with the increase of the disturbance frequency. The intrusive resistance of the cone bit decrease gradually with the increase of the disturbance frequency. References | Related Articles | Metrics

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Surface Rock Mass Quality Evaluation for High-Level Radioactive Waste Disposal of Beishan Preselected Area and Its Application WEI Xiang， YANG Chun-he， CHEN Shi-wan， HUO Liang 2017, 38 (10):  1507-1511.  DOI: 10.12068/j.issn.1005-3026.2017.10.028 Abstract ( 599 )   HTML   PDF (659KB) ( 616 )   Based on the use of surveying method for surface joint investigation and statistics， a surface rock mass quality evaluation method based on the index-JSR was proposed. Taking the high-level radioactive waste disposal of Beishan preselected area as research object， the index-JSR was used to evaluate rock mass joint development degree and quality in the Jijicao section， Suanjingzi section and Xinchang section. The results showed that joints in the Jijicao section are less developed and the rock mass quality for Jijicao section is higher than that of Suanjingzi section. The results can provide site select basis for high-level radioactive waste geological disposal. At the same time， the quantitative relationship between JSR and Q was studied， and the scope of JSR index classification was corrected. References | Related Articles | Metrics

Management Science

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Influence of MNC Legitimacy on Control Strategy of Subsidiaries After M & A GENG Yuan-xin， DU Xiao-jun 2017, 38 (10):  1511-1515.  DOI: 10.12068/j.issn.1005-3026.2017.10.029 Abstract ( 646 )   HTML   PDF (363KB) ( 742 )   Under dual pressure of institution and competition， the relation between MNC legitimacy and MNC subsidiaries control was studied on the basis of the institution and organizational ecologies. The questionnaire sample data of equipment manufacturing industry and high-tech service industry showed that the relations between MNC legitimacy and subsidiary ownership ratio， expatriate staffing ratio were influenced by competition. With the increase of legitimacy， MNC tends to increase the ownership ratio and expatriate staffing ratio for the less fierce competition subsidiaries (smaller subsidiaries)， while MNC tends to reduce the ownership ratio and expatriate staffing ratio for the fierce competition subsidiaries (large subsidiaries). References | Related Articles | Metrics

Mathematics

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Exact Solutions for IBq Equation with Fluid Dynamic Damping SONG Shu-ni， FAN Kai 2017, 38 (10):  1516-1520.  DOI: 10.12068/j.issn.1005-3026.2017.10.030 Abstract ( 694 )   HTML   PDF (639KB) ( 819 )   The IBq equation with fluid dynamic damping was studied. Many studies of exact solutions for Bq equation were found， but the study results of the IBq equations were very few. The standard Tanh method and the extended Tanh method were introduced to solve nonlinear evolution equation， and the standard Tanh method and symbolic computation system Maple were used to obtain a large number of exact hyperbolic function solutions of IBq equation with fluid dynamic damping， mainly for the kink and the antikink soliton solutions. Assignment of exact solutions was done for the unknown parameters， and figures showed some exact solutions， which were useful for verifying the accuracy and stability of numerical solution. The obtained results confirm that the proposed methods are efficient techniques for analytic treatment of a wide variety of nonlinear partial differential equations in mathematical physics. References | Related Articles | Metrics