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15 November 2020, Volume 41 Issue 11 Previous Issue    Next Issue
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Information & Control

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An Applicable Multivariate Decision Tree Algorithm for Categorical Attribute Data LIU Zhen-yu， SONG Xiao-ying 2020, 41 (11):  1521-1527.  DOI: 10.12068/j.issn.1005-3026.2020.11.001 Abstract ( 719 )   HTML   PDF (409KB) ( 929 )   Most multivariate decision trees are applicable for only the numerical data. To solve the classification problem on categorical attribute data， an applicable multivariate decision tree(CMDT) algorithm is proposed. The center of the sample set on the categorical attributes， and the distance between the samples and the centers are defined with statistics for frequency distribution of categorical attribute values in each category or each cluster. Weighted k-means algorithm is utilized to split the nodes in the decision tree. The proposed multivariate decision tree is applicable for numerical data， categorical data， and mixed data. Experiment results show that the classification model based on the proposed algorithm can get more concise tree construction and higher generalization accuracy than that based on the classic decision tree algorithms with different kinds of data. References | Related Articles | Metrics

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Sampled-Data-Based Consensus Control for Large-Scale Energy Storage System YAN Shi-jie， WANG Li-hua， YAN Wei-hang， GAO Wen-zhong 2020, 41 (11):  1528-1534.  DOI: 10.12068/j.issn.1005-3026.2020.11.002 Abstract ( 553 )   HTML   PDF (518KB) ( 617 )   Aiming at the inconsistent problem of state of charge(SOC) caused by the energy storage batteries in large-scale energy storage systems， a consensus control method for multi-agent energy storage systems is proposed， which realizes consistency of the SOC and the output power. The simplified large-scale energy storage system model is applied， and the consensus control protocol is designed based on the sampled data， and the convergence is analyzed. The local energy storage agent only receives the state information of the adjacent energy storage agents at a specific sampling time point， and can generate the local energy storage control signal， which solves the problem of large-scale multi-agent energy storage system due to the large calculation burden because of the complex communication. Considering the sampling data and system requirements， the system control parameters are designed. At the same time， taking into account the excessive instantaneous power， the consistency control with power limitation is improved. Finally， simulations are studied in three scenarios:meeting the theorem conditions， not satisfying the theorem conditions， and power limitation. The effectiveness of the method is verified. References | Related Articles | Metrics

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Optimization of High-Speed Train Operation Plan for OD Passenger Flow TIAN Hui-xin， WANG Di， SHUAI Min-wei， LI Kun 2020, 41 (11):  1535-1542.  DOI: 10.12068/j.issn.1005-3026.2020.11.003 Abstract ( 661 )   HTML   PDF (683KB) ( 745 )   The train operation plan that meets the passenger travel needs can better attract passenger flow and improve the core competitiveness of high-speed railway. The maximization of economic benefits and the minimization of travel expenses as the research objects， the high-speed rail operation plan as the research object， and the travel demand of passengers as constraints are taken. The train operation plan is combined with the OD passenger flow. Taking into account the passengers’ purchase psychology and the timeliness of train ticket purchase， a multi-objective optimization model of train operation plan is established based on dynamic passenger flow. In order to solve the problem， a multi-objective differential (SG-MOSaDE) algorithm is designed based on individual information and the improved mutation operator. Taking a certain route in Guangzhou as an example， the results show that the optimized operation plan not only maximizes meeting the passenger travel demand， but also reduces the travel expenses of the passenger while improving the economic benefits of the railway sector. The number of stations has decreased compared with the original， and the stop plan is more balanced. References | Related Articles | Metrics

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Model Parameter Online Identification Based SOC Estimation Method LIU Fang， MA Jie， SU Wei-xing， HE Mao-wei 2020, 41 (11):  1543-1549.  DOI: 10.12068/j.issn.1005-3026.2020.11.004 Abstract ( 699 )   HTML   PDF (790KB) ( 807 )   In view of the problems that genetic algorithm (GA) has slow convergence speed， be easy to fall into local optimum and difficult to realize online application， and that the identification background of power battery equivalent circuit model is with strong nonlinearity and high real-time requirements. An optimized identification framework is proposed that can quickly reduce the search space and effectively avoid falling into the local optimum for online fast search， thus realizing the online fast identification of the parameters of the equivalent circuit model of the electric vehicle power battery， and expanding the application range of the global search optimization algorithm. Further， the proposed algorithm is applied to the state of charge (SOC) estimation， based on the improved GA unscented partical filter (IGA-UPF) is proposed. The SOC estimation method is compared with the SOC estimation method based on least square-unscented partical filter (LS-UPF)， which proves that the online fast parameter identification framework proposed has better model parameter identification accuracy. References | Related Articles | Metrics

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A Feature Selection Method Based on New Redundancy Measurement LI Zhan-shan， LYU Ai-na 2020, 41 (11):  1550-1556.  DOI: 10.12068/j.issn.1005-3026.2020.11.005 Abstract ( 633 )   HTML   PDF (401KB) ( 687 )   The current filter feature selection models use greedy strategy combined with mutual information to evaluate feature subsets， which are easy to fall into the local optimum trap. Considering the effect of label information on redundancy， an improved MIFS-U method is used to measure the redundancy under the condition of a given label. A decomposition-based multi-objective optimization framework combined with a differential evolution operator that introduces polynomial mutation is used for global search to avoid searching into local optimum. The l1 regularization is introduced to ensure the sparsity of the feature subset， and a new feature selection algorithm MOEA/D-DEFS is proposed. In the experimental stage， the knn-5 classifier is used to verify the learning effect， by the tests on multiple sets of data sets from different fields. The results show that considering feature selection as a multi-objective problem and using a global search strategy can provide better performance in terms of feature subset dimensions and classification accuracy. References | Related Articles | Metrics

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State Co-estimation Algorithm for Li-Ion Power Batteries Based on Adaptive Unscented Kalman Filters ZHANG Jun-hui， LI Qing， CHEN Da-peng， ZHAO Ye 2020, 41 (11):  1557-1563.  DOI: 10.12068/j.issn.1005-3026.2020.11.006 Abstract ( 600 )   HTML   PDF (584KB) ( 737 )   On the practical issues such as accumulative state estimation errors caused by the inaccurate battery model， and time-varying and unknown noise statistical characteristics， a state co-estimation algorithm for Li-ion power batteries based on adaptive unscented Kalman filter (UKF) framework is proposed. During the iteration process， the measurement equation called by unscented transform (UT) each time is quasi-linearized， which could greatly reduce the computational complexity. The statistical characteristic parameters of unknown noises can be estimated by introducing Sage-Husa adaptive estimation method with forgetting factor， which could improve the adaptive fault tolerance of UKF estimation algorithm. If the divergence trend occurs in the filtering process， the error covariance will be penalized by employing adaptive attenuation factor to prevent the divergence of the filter， accordingly guaranteeing the numerical stability of filtering process. By employing co-estimation strategy， the inner ohmic resistance of the 1st-order Thevenin battery model， which could characterize the state of health (SOH) indirectly， can be estimated and adjusted in real time， and therefore a high-precision estimation of the state of charge (SOC) is able to be obtained owing to the accuracy of the battery model during the process of dynamic charge-discharge cycling tests. The comparative experimental results verify the feasibility and effectiveness of the adaptive co-estimation algorithm. References | Related Articles | Metrics

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Dual-channel Multi-perception Convolutional Network for Image Super-Resolution WANG Xin， WANG Cui-rong， WANG Cong， YUAN Ying 2020, 41 (11):  1564-1570.  DOI: 10.12068/j.issn.1005-3026.2020.11.007 Abstract ( 771 )   HTML   PDF (806KB) ( 735 )   Rececnt researches on single-image super-resolution based on deep convolutional neural networks have achieved remarkable results. However， with increasing neural network scale， to reduce the network constructing difficulty and the computation costs has become a difficult issue. To solve this problem， a dual-channel multi-perception convolutional neural network (DMCN) is proposed. Specifically， the dense skip connection between two convolutional channels with different sizes of convolution kernels is established. Then， an adjustable inter-layer fusion structure is established between different layers. This structure makes it possible to learn abundant image feature information through a small-scale convolutional neural network. The experimental results show that the proposed model outperforms most of the typical algorithms. References | Related Articles | Metrics

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Fully Automatic Location Method of Ostial Layers and Points of Coronary Arteries for Computed Tomographic Angiographic Images LUO Yang， QI Lin， XU Li-sheng 2020, 41 (11):  1570-1576.  DOI: 10.12068/j.issn.1005-3026.2020.11.008 Abstract ( 984 )   HTML   PDF (1218KB) ( 704 )   Firstly， the ostial layer of the left coronary arteries by change of roundness is determined on the basis of multi-condition region growth and the anatomic structure， and the ostial point of the left coronary arteries within the specified range is determined.Secondly， the ascending aorta center and the ostial range of the right coronary arteries are calculated， and the peaks and valleys of the distance curve combined with the features of the anatomic structure are utilized to determine ostial layer and point of the right coronary arteries. The parameters of the proposed method are statistically verified. Finally， 57 subjects are tested. The accuracy of locating the ostial layers of left and right coronary arteries are 98.2% and 96.5%， respectively. The average distances between located ostial points of left and right coronary arteries and the ground truth are (1.22± 0.37)mm and (1.76± 0.49)mm， respectively. The experiments demonstrate the validity of the proposed method. References | Related Articles | Metrics

Mechanical Engineering

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Flexible Joint Control Strategy Based on Posture Change of Transmission Line Inspection Robots LI Xiao-peng， SHANG Dong-yang， LI Fan-jie，WEN Bang-chun 2020, 41 (11):  1577-1583.  DOI: 10.12068/j.issn.1005-3026.2020.11.009 Abstract ( 1302 )   HTML   PDF (1773KB) ( 756 )   In order to reduce the fluctuation degree of output velocity of flexible joints of transmission line inspection robots， the controller parameter of the flexible joint servo drive system is designed by pole assignment. The choice of this parameter changes with the change of the robot posture so that the robot flexible joint servo drive system can obtain a stable output speed. Firstly， the dynamic equation of the robot flexible joint servo drive system is established and the transfer function of motor speed to electromagnetic torque is obtained. Then PI control strategy is applied to the flexible joint servo control to obtain the closed-loop transfer function of the control system. Then the pole assignment strategy with the same damping coefficient is used to design the controller parameter. Finally， the experiment of flexible joint control under the condition of the patrol robot surmounting obstacles is carried out， which shows that the flexible joint can obtain a good output speed by selecting pole assignment parameters properly. References | Related Articles | Metrics

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Patient Registration for Surgical Navigation System Based on Three-Point Method and ICP Algorithm ZHANG Chun-lei， DAI Li， LIU Yu， LI He 2020, 41 (11):  1584-1590.  DOI: 10.12068/j.issn.1005-3026.2020.11.010 Abstract ( 625 )   HTML   PDF (1350KB) ( 919 )   To improve the accuracy and operation efficiency of patient registration for the surgical navigation system， the registration strategy which combined three-point method and iterative closest point (ICP) algorithm was proposed. Firstly， the patient registration problem was defined and the acquisition methods of preoperative and intraoperative data were introduced. Then， the spherical center of the optical positioning markers were taken as the common features between patient space and image space， and the initial registration was completed by using the three-point method. Finally， the spherical regions with radius r were established by taking each point of patient point cloud after initial mapping as the spherical center， and the points of image point cloud located in these regions were retained to realize sampling， and the improved ICP algorithm was used to perform accurate registration of the two point clouds. The experimental results showed that the mean registration errors for pig femur and pig ilium when using the proposed method are (0.83±0.10)mm and (0.86±0.09)mm， respectively， which is superior to the traditional ICP algorithm in terms of accuracy and stability， and is efficient and easy to operate with certain potential values in clinical applications. References | Related Articles | Metrics

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Automatic Compensation Algorithm of Phase Aberration in Digital Holographic Microscopy MA Shu-jun， FANG Rui 2020, 41 (11):  1591-1595.  DOI: 10.12068/j.issn.1005-3026.2020.11.011 Abstract ( 890 )   HTML   PDF (1130KB) ( 697 )   An automatic compensation algorithm of phase aberration for digital holographic microscopy based on image segmentation is proposed. Firstly， the least square fitting method is used to roughly compensate the unwrapped phase map containing the measured object. On this basis， the image segmentation algorithm is used to segment the background region to obtain the unwrapped phase map without the measured object. Finally， the least square fitting is carried out to realize the accurate compensation of phase aberration. The traditional digital holographic microscopy needs to detect the background region manually to solve the problem of phase aberration compensation. However， the proposed method can achieve the automatic compensation of phase aberrations without any manual intervention or prior knowledge of optical setup. The accuracy and feasibility of the algorithm are verified on the experiment platform of digital holographic microscopy. References | Related Articles | Metrics

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A Detection Mechanism for On-line Measuring the Position Relationship of Vertical Parallel Planes LU Ze-chen， ZHAO Chun-yu， LI Zhen-jun 2020, 41 (11):  1596-1602.  DOI: 10.12068/j.issn.1005-3026.2020.11.012 Abstract ( 599 )   HTML   PDF (979KB) ( 641 )   Because the machine tool is characterized by large mass and difficulty in moving， it is always a difficult problem to measure the position error of its vertical positioning surface on the spot. Therefore， a detection mechanism is designed which can measure the position relationship of the vertical parallel planes in the field. The detection mechanism can use the geometric relationship between itself and the parallel plane’s shape contour to separate the known datum plane’s shape profile， and the calculated shape profile of the measured plane can be thus obtained. According to the difference between the calculated shape profile and the known measured plane shape profile， the position relationship between the two parallel planes can be determined. Meanwhile， the principle of the detection mechanism is introduced， the detection scheme is given， the algorithm for describing the position relationship is developed， and the measurement test is carried out. The experimental results show that the detection mechanism can accurately obtain the position relationship between the two vertical parallel planes. References | Related Articles | Metrics

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Analysis of Material Removal and Hole Formation Process in Ball Helical Milling Process WANG Hai-yan， TAO Ke-xin， JIN Tian 2020, 41 (11):  1602-1608.  DOI: 10.12068/j.issn.1005-3026.2020.11.013 Abstract ( 699 )   HTML   PDF (1168KB) ( 675 )   According to the cutting mechanism of helical milling technology， considering the machining characteristics of titanium alloy and geometric features of ball milling cutters， the shape and relative positional relationship between the tool and the workpiece at different characteristic moments were discussed， and four typical moments were selected to study the hole wall formation mechanism. The section characteristics and cross section area of the removed undeformed cutting materials were discussed， and the material removal behavior was analyzed through typical moments in the ball helical milling process. The experiments in ball helical milling of titanium alloy were carried out， the cutting forces were measured， and the tool wear and hole making quality were studied. The results showed that the materials removal process in ball helical milling is uniform and stable basically consistent with the simulation process， and the cutting forces increase or decrease gradually with slight tool wear and high hole-making quality. References | Related Articles | Metrics

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Analysis of Meshing Characteristics of Modified Gear Pair Under Misalignment MA Hui， ZHAO Bai-shun， HUANGFU Yi-fan， HAN Chen-yi 2020, 41 (11):  1609-1614.  DOI: 10.12068/j.issn.1005-3026.2020.11.014 Abstract ( 558 )   HTML   PDF (1568KB) ( 736 )   The effect of the misalignment can be alleviated effectively by applying proper lead crown relief so that the contact state and the transmission stability can be improved. An analysis model considering gear tooth modification and misalignment is established based on the theory of loaded tooth contact analysis， and the validity of the model is verified by ANSYS. The time-varying mesh stiffness and contact stress of the gear pair under different contact states are analyzed. Finally， with reducing the contact stress of the tooth surface as the optimization objective， the quantity of the lead crown relief of the gear pair is optimized. The calculation efficiency is greatly improved under the premise of ensuring the calculation accuracy. The study provides a theoretical basis for the optimization of tooth modification for gears with misalignment. References | Related Articles | Metrics

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Temperature Prediction Model of Bone Material Micro-milling Cutting Edges LIU Yu， CHEN Qi-sen， DONG Qiu-shi 2020, 41 (11):  1615-1622.  DOI: 10.12068/j.issn.1005-3026.2020.11.015 Abstract ( 453 )   HTML   PDF (876KB) ( 622 )   Due to the brittleness of bone materials and micro-milling characteristics， there is no effective theoretical prediction model for bone milling cutting edge temperature currently. A novel temperature prediction model of bone material micro-milling cutting edges was proposed. Considering the characteristics of generation， transmission and distribution of heat in bone material high-speed micro-milling， the prediction model was divided into two sub-models:milling heat generation model and cutting edge temperature model. Then， a bone milling experimental platform was established， and the cutting edge temperatures during the milling process were collected by a thermal imager. Finally， by comparing the experimental results with the theoretical predictions， the rationality of the built temperature prediction model of bone material micro-milling cutting edges was verified. The model is helpful to guide doctors to select appropriate processing parameters according to different requirements， and assist engineers in tool optimization design. References | Related Articles | Metrics

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On the Cross Flow Regime Pumping Performance of Turbomolecular Pumps Based on DSMC Method LI Bo， MA Zhao-jun， WANG Xiao-dong， BA De-chun 2020, 41 (11):  1623-1628.  DOI: 10.12068/j.issn.1005-3026.2020.11.016 Abstract ( 564 )   HTML   PDF (565KB) ( 707 )   Based on the direct simulation Monte Carlo (DSMC) method， the pumping performance of TMP (turbomolecular pump) blades in different rarefied gas flow regimes can be calculated. By changing the rotating speed， air inlet structure and the temperature of the pumped gas， the change of maximum pumping efficiency and maximum compression ratio of TMP can be obtained， and the influencing degree of each parameter on the performance of TMP in different flow regimes can be compared. At the same time， the change of the return flow of the turbine blades in different flow regimes is calculated. It is concluded that increasing the blade speed in the molecular flow regime can significantly improve the performance， and reducing the gas inlet area can improve the compression ratio of TMP， so as to provide the means to improve the performance and expand the working range of TMP. References | Related Articles | Metrics

Resources & Civil Engineering

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Joint Correlation Imaging Inversion with Gravity Gradiometry Data Based on Depth Weighting HOU Zhen-long， ZHENG Yu-jun， GONG En-pu， CHENG Hao 2020, 41 (11):  1628-1632.  DOI: 10.12068/j.issn.1005-3026.2020.11.017 Abstract ( 561 )   HTML   PDF (797KB) ( 709 )   Aiming at the low vertical resolution of correlation imaging inversion in the mineral exploration， a correlation imaging inversion based on depth weighting with gravity gradiometry data is proposed. The vertical space resolution of the inversion would be improved by the means of combining multiple gravity gradiometry tensors， introducing the depth weighting function based on the prior information and the underground zonal weighting method. In the data test，it is demonstrated by the cube-combination model that the proposed method could inverse the objective location accurately， the numerical range of computed density is consistent with the theoretical model， and the method has the anti-noise ability. The inversion is then applied to the real gravity gradiometry data from Vinton Dome， U. S.， the location of the cap rock displayed in the results conforms to the known geological information. It is proved that the method is effective and practical. References | Related Articles | Metrics

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Numerical Simulation Study on Hysteresis Characteristics of Transmission Tower Bolt Joints LI Jia-xiang， WANG Biao， SUN Jian， WANG Shu-hong 2020, 41 (11):  1633-1639.  DOI: 10.12068/j.issn.1005-3026.2020.11.018 Abstract ( 628 )   HTML   PDF (757KB) ( 742 )   During the vibration of the transmission tower， the bolt joints will move back and forth， but there is still a lack of research on the dynamic characteristics of the bolt joints. The numerical simulation of joint bolt slip is carried out to analyze its hysteresis performance under cyclic loading. The effects of initial clearance， bolt torque， and contact surface roughness on the hysteresis performance of typical bolt joints are studied through parameter analysis， which provides a reference hysteretic model for simulating the dynamic response of bolt slip. The results show that the smaller the initial clearance， the larger the coefficient of the friction， the greater the initial torque， and the smaller the limit deformation of the hysteresis curve， in which the initial gap has the greatest effect on the slip deformation. References | Related Articles | Metrics

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Study on Indoor Model Test of Suspended Water Curtain ZHANG Qin-xi， YAN Jin-bo， WANG Cheng-ming， ZHANG Zhi-hong 2020, 41 (11):  1640-1645.  DOI: 10.12068/j.issn.1005-3026.2020.11.019 Abstract ( 688 )   HTML   PDF (1916KB) ( 725 )   In order to accurately reveal the water control law of the foundation pit under the condition of suspended water-stopping curtain， the indoor groundwater seepage model test was carried out to study the influence of the curtain insertion depth on the water inflow in the foundation pit， the influence radius of precipitation， the water level drop outside the foundation pit and the ground settlement. The test results show that taking the water inflow in the foundation pit， the water level drop outside the foundation pit and the ground settlement as evaluation indexes， the curtain insertion depth is between 90~100cm， and the hanging water-stop curtain has a good water control effect; taking the influence radius of precipitation as the evaluation index， the curtain insertion depth is between 80~90cm， and the hanging water-stopping curtain has a good water control effect; the ratio of water head loss in the pit and outside the pit to total water head loss is close to 1∶1. The water head loss in the small range at the bottom of the curtain accounts for a very small proportion and is also less affected by the depth of curtain insertion. The test results can provide reference for foundation pit dewatering design of suspended water curtain. References | Related Articles | Metrics

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Analysis of Poor Crack Configuration Influence Based on ABAQUS Standard Extended Finite Element Method FANG Shu-jun， WANG Tao， NIE Nian-cong， ZHANG Ling-rui 2020, 41 (11):  1646-1653.  DOI: 10.12068/j.issn.1005-3026.2020.11.020 Abstract ( 590 )   HTML   PDF (915KB) ( 708 )   In practical applications， the analysis of crack problems by the extended finite element method(XFEM) has the problems of highly ill-conditioned overall stiffness matrix， singularity of matrix， etc. The numerical simulation does not achieve the ideal requirement that the analysis result has nothing to do with meshing. The three-point bending beam test was selected based on the ABAQUS platform， and the discrete Freschet distance was introduced to evaluate the difference in crack development path with time history. The influence of the poor crack configuration related to meshing on the simulation results in the application of the standard XFEM was analyzed. The results show that the initial crack endpoint must be at the element boundary during numerical simulation to avoid weakening the components， and poor crack configuration will cause the distortion of the crack development path simulation， and the distortion will increase as the poor coefficient decreases. The poor coefficient u should be controlled within 0.25~1. The convergence and path accuracy can be improved by introducing viscous damping. References | Related Articles | Metrics

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Experimental Study on Similar Materials Ratio Used in Large-Scale Engineering Model Test LI Guang， MA Feng-shan， GUO Jie， ZHAO Hai-jun 2020, 41 (11):  1653-1660.  DOI: 10.12068/j.issn.1005-3026.2020.11.021 Abstract ( 843 )   HTML   PDF (1082KB) ( 902 )   Large-scale physical model test is an important method to study complex engineering problems， in which the similar material proportion selection is a crucial part. In order to reduce the test cost， simplify the test procedures， and fully utilize the properties of raw materials， the river sand， cement and gypsum was adopted as the raw materials， and 45 groups of comparative tests with bone-glue ratio and water-cement ratio was conducted as variables. The physical， dynamic and static dynamics parameters of similar materials were studied， and the main conclusions were as follows: the variation ranges of physical quantities of similar materials made from river sand， cement and gypsum are obtained; the effects of bone-glue ratio and water-cement ratio on the physical quantities of similar materials are discussed and the sensitivities are compared. The quantitative relationship between each factor and physical quantity is established based on multiple linear regressions analysis and the fitting formula can describe the properties of similar materials well. References | Related Articles | Metrics

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Effect of Substitution of Ceramic Fine Aggregate on Compressive Strength of Concrete CHENG Yun-hong， YANG Si-hui， ZHANG Jing-yu， TONG Bai-qiang 2020, 41 (11):  1661-1666.  DOI: 10.12068/j.issn.1005-3026.2020.11.022 Abstract ( 550 )   HTML   PDF (498KB) ( 623 )   In order to improve the utilization rate of waste ceramics in concrete， ceramic concrete was prepared by using “C” substitution method (traditional equal mass substitution method)，“P” substitution method (substitute natural river sands with different particle sizes)， “D” substitution method (substitute natural river sands with particle sizes of 1.18， 2.36 and 4.75mm) and “X” substitution method (substitute natural river sands with particle sizes of 0.15， 0.3 and 0.6mm.) to replace natural fine aggregate according to different proportion (10%， 20%， 30%， 40%， 50%). 21 groups of concrete were designed， including 1 group of reference concrete， 5 groups of concrete prepared of “C”， “P”， “D” and “X” substitution method respectively. The water-binder ratio is 0.49， and the compressive strength test of concrete takes for 28 days. The results show that when the water-binder ratio is 0.49 and the ceramic fine aggregate content is less than 50%， the compressive strength of ceramic fine aggregate concrete and the reference concrete are of the same strength level， and all reach the strength level of C30. The optimal substitution rate is different for different ceramic fine aggregate substitution methods. Different substitution rates of ceramic fine aggregate correspond to different optimal substitution methods. References | Related Articles | Metrics

Materials & Metallurgy

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Effect of TiO2 Content on Metallurgy Performance of High-Chromium Vanadium-Titanium Magnetite Sinter ZHANG Li-heng， GAO Zi-xian， TANG Wei-dong， XUE Xiang-xin 2020, 41 (11):  1667-1672.  DOI: 10.12068/j.issn.1005-3026.2020.11.023 Abstract ( 556 )   HTML   PDF (1854KB) ( 637 )   High-chromium vanadium-titanium magnetite (HCVTM) and ordinary magnetite are used as raw materials to explore the influence of TiO2 content on the properties of HCVTM sinter by sintering cup test.The results show that as the TiO2 content increases from 6.30% to 11.76%， the tumbler index and sinter strength decrease while the vertical sintering speed，yield， and sintering utilization coefficient show the increasing tendency.The proportion of the tiny sinter particles with a diamater less than 5mm decreases gradually and the overall sinter size increases.With the increase of the TiO2 content， the hematite decreases， and the magnetite， CaTiO3 and Fe9TiO15 increase.The low temperature reduction degradation index shows an increasing tendency， while the reducibility decreases with the increase of TiO2 content. References | Related Articles | Metrics