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31 March 2021, Volume 31 Issue 1 Previous Issue    Next Issue
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Technology Theory and Application
Management Science Research
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Technology Theory and Application

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Study on Mechanical Properties of Silt Soil Hardening Materials WANG Wei-min, WANG En-zhi, LIU Xiao-li, ZHANG Lu-jun 2021, 31(1): 1-9.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.001 Abstract ( )   PDF (1134KB) ( )   Soil curing agent has been used widely in the engineering field since 1990 s.There are many studies focused on the use of cement or ion exchange curing agent on the soft soil foundation hardening,but the study on sand or other curing agent is rare.In this paper,the main material is medium-coarse sand from the engineering field of Fenhe Reservoir's bank,and the curing agent is water glass provided by Institute of Materials of Tsinghua University.The test piece of solidified soil was prepared by vibrating.The amount of curing agent,maintenance environment and test age are three variables of the contrast test.The unconfined compressive strength of test pieces are obtained by uniaxial compressive test,and the influencing factors of the results are analyzed,and the curing principle and constitutive relation of the solidified soil are discussed preliminarily. References | Related Articles | Metrics

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Improved Fruit Fly Optimization Algorithm for Path Planning in Vehicle Navigation System LI Zhe, WANG Jia-wei, LV Meng, LIANG De-yu 2021, 31(1): 10-14.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.002 Abstract ( )   PDF (523KB) ( )   In vehicle navigation systems,the aim of path planning techniques is to obtain the appropriate route for drivers.This problem and associated methods are very important in intelligent transportation  system.Finding the best route in complex urban streets is the typical nonlinear optimization problem.In these years,swarm intelligence algorithms are widely utilized in such issues and have shown some advantages.In this paper,some blocks in Tangshan city are modeled as nodes with related longitudes and latitudes. An improved fruit fly algorithm is designed for solving path planning task.Fitness function is adjusted for discrete optimization and some operators in genetic algorithm are introduced.Simulation experiments show that the algorithm designed in this paper is able to obtain a better route from the starting node to the destination.The cost of driving is reduced. References | Related Articles | Metrics

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Calculation method of ultimate bearing capacity of ring reinforced gravel pile WANG Chao 2021, 31(1): 15-21.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.003 Abstract ( )   PDF (1837KB) ( )    Compared with traditional gravel piles, geosynthetic ring-reinforced gravel piles have higher pile strength. The bearing capacity is usually controlled by the strength of the pile. Therefore, the calculation of the strength of the reinforced gravel piles has great significance for design. In this paper, considering the effect of circumferential reinforcement of geosynthetics and the additional stress of the surrounding soil, the calculation method for the strength of the ring-reinforced gravel pile is deduced. Then, the calculation method for the bearing capacity of a single pile determined by the strength of the pile is established. Combined with numerical analysis, the analytical solution of its bearing capacity is revised. The research results can provide a basis for the bearing capacity design of the ring-reinforced gravel pile composite foundation. References | Related Articles | Metrics

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Research on Vibration Characteristic and Seismic Performance of Long-span Space Suspended Structure ZHANG Jin, YANG De-jian 2021, 31(1): 22-26+31.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.004 Abstract ( )   PDF (2771KB) ( )   As a new damping structure, suspended structure system attract a lot of attention of engineers because of its reasonable force transmission path, high material utilization and good damping effect. A long-span space suspended structure system which is rarely seen in domestic is adopted by the Tianjin Theatre, in which tow floors are suspended on lower chords of the roof by about 160 high strength steel. This article established a finite element model of Tianjin Theatre using SAP2000, and analyzed the vibration characteristic and dynamic performance of both the whole model and the equivalent model. The results indicate that the mode shape of the space structure is complex and the mode frequency is densely, local vibration always shows in low order while common vibration occurs in higher order. The suspended floors perform well on damping effect . References | Related Articles | Metrics

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Concrete Fast Freeze-thaw Test System Based on PLC and Kingview HAO Rui-lin, LI Yan, GUO Fang, SUN Ying-jian, ZHANG Huan-ling 2021, 31(1): 27-31.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.005 Abstract ( )   PDF (645KB) ( )   In order to improve the reliability and practicability of the concrete fast freeze-thaw test system, the control system is constructed by Siemens 200SMART series PLC and KingView software. It is composed of PLC, temperature sensors, contactor and power circuit in the slave system, in which the temperature of concrete sample and surrounding liquid are collected by the AR04 module and temperature sensor PT100. Meanwhile, the host system is based on KingView software, which can set cycle times and temperature limit of automatic heating / cooling, record the temperature of each channel, and view the historical data and curves, etc. After calculation, the data accuracy has been improved by two grades, and the function of recording temperature and viewing historical data are developed, which can meet the needs of scientific research and quality supervision. The test results show that the system has high reliability and strong practicability. It can provide users with accurate historical data and curves, and lay a foundation for further data analysis. References | Related Articles | Metrics

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Research on the Impact of Climate Change on Upstream Runoff of Tang River Based on SWAT GAO Xiang, FENG Jian, SI Zhong-qiang, XU Jing 2021, 31(1): 32-36.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.006 Abstract ( )   PDF (479KB) ( )   In order to study the effects of climate change on the runoff of the upper reaches of the Tang River, the study used SWAT model and setting up three scenarios, quantitatively analyzes the change of climate change to the runoff of the upper reaches of Tang River, and the results show that:the calibration and validation results of SWAT model indicate that the simulation results meet the requiremrnt of the model.In the period of calibration, ENS is 0.65, R2 is 0.73.In the period of validation, ENS is 0.7, R2 is 0.76,and that the results were good for model.(ii)When precipitation increased by 20% and 10%, the average monthly runoff was increase 7.65m3/s (8.9%) and 4.37m3/s (5.1%). When precipitation was reduced by 20% and 10%, the average monthly runoff decreased by 5.2m3/s (6.1%) and 2.03m3/s (2.4%). When temperatures increased 1℃ and 2℃ respectively, the average monthly runoff in the basin decreased by 0.73m3/s (0.09%) and 2.18m3/s (2.5%), respectively. It shows that the change of runoff and rainfall in the basin are positively correlated with the change of temperature, and the change of temperature is negatively correlated. By predicting the rule of runoff under the future climate scenario of the upper reaches of Tang River basin, we can provide a scientific reference for the policy departments in the rational allocation of water resources in the future. References | Related Articles | Metrics

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Research on a Detection Method of Capacitance Current to Ground ZHOU Rui, XIA Jun-ya, ZHENG An-yu, HOU Yi-xiang 2021, 31(1): 37-40+61.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.007 Abstract ( )   PDF (581KB) ( )   This paper presents a method to measure the capacitance current of neutral point through the parallel damping grounding system of arc suppression coil, which is convenient to realize the tracking and tuning of arc suppression coil. By changing the neutral grounding resistance, the amplitude and phase angle of the current flowing through the neutral before and after the change of the neutral grounding resistance are measured, and the system mismatch degree is calculated by the amplitude and phase angle of the current measured twice, so as to calculate the current value of the system to the ground capacitance. The accuracy of the method is verified by building a model in MATLAB. The simulation shows that the method can effectively measure the current value of the ground capacitance, the acquisition quantity is easy to obtain, and the calculation accuracy meets the requirements. It provides a theoretical basis for the tracking and tuning of the arc suppression coil based on the measured current. References | Related Articles | Metrics

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Study on Seismic Behavior of Prestressing Prefabricated Concrete Frame Joints with Three Stories and Single Span HU Shan-shan, Yang Xiao-bo 2021, 31(1): 41-45.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.008 Abstract ( )   PDF (743KB) ( )   Under the guidance of China＇s construction industrialization policy,how to improve the assembly performance of prefabricated component joints is a common concern of the construction industry.Based on the quasi-static seismic test of a three story single span prefabricated prestressed concrete frame,the crack and damage of each joint in the ultimate failure state of the test frame are understood,and the crack resistance degree of each joint is calculated and analyzed.According to the load(displacement)-shear angle hysteretic curve,the deformation characteristics and shear transfer mechanism of the joint core area are discussed,and the nonlinear simulation is carried out by using the ANSYS finite element software. The research results show that the failure of prefabricated prestressed concrete frame occurs at the beam end,while the core zone of the joint does not occur under the condition of bidirectional stress.The whole structure has good ductility,and the core area of joints has strong anti-crack and anti-deformation ability,which meets the seismic design requirements of“strong joints and weak members”. References | Related Articles | Metrics

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Design of Bolt Disassembly Equipment for Large Machinery and Equipment ZHOU Li-jie, LIU Hui, GAO Bo, HAO Rui-lin, SHI Yan 2021, 31(1): 51-55.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.010 Abstract ( )   PDF (1016KB) ( )   In the repair process of large machinery and equipment,it has the characteristics of high operating position,scattered operating points,heavy bolt disassembly tools,and high labor intensity.These characteristics reduce the maintenance efficiency.In view of these characteristics,in this paper,a auxiliary arm is designed for bolt disassembling.This equipment consists of power assisted mechanical arm,electric hydraulic lifting platform,electrical powered module and supporting apparatus.Integrated with air springs,the power assisted mechanical arm can not only compensate the gravity of service tools but also can reduce the labor of repairmen.The power assisted mechanical arm has large-scale operation space.With the design of two-stage arms,the power assisted mechanical arm can turn 360 degrees and move up and down.The auxiliary arm for bolt disassembling contains electric hydraulic lifting platform and electrical powered module.The electric hydraulic lifting platform is available tohigh operating position.The electrical powered module can be used to move flexibly and efficiently.The supporting apparatus can provide effective support for the auxiliary arm in high-altitude operations.The equipment is simple in structure,convenient in operation,and well-adapted,which can be used to bolt disassembly operation for engineering machinery,mineral equipment,oversize vehicle,and so on. References | Related Articles | Metrics

Management Science Research

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Research on the Influence of Industrial Structure Optimization on Power Consumption under the Background of High Quality Development WANG Shuai, ZHOU Ming-sheng 2021, 31(1): 56-61.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.011 Abstract ( )   PDF (256KB) ( )   By distinguishing between the rationalization of industrial structure and the upgrading of industrial structure,this paper empirically investigated the influence of industrial structure optimization on power consumption by using provincial panel data from 2003to 2018.The results show that the rationalization and upgrading of industrial structure can reduce the total electricity consumption,but there is a certain regional heterogeneity.Due to the advantage of industrial development stage in coastal areas,the weak change of the Theil index did not lead to the increase of power consumption,and the overall negative correlation was observed.Based on this,this paper points out that it is necessary to continue to strengthen the optimization of industrial structure at the present stage,and rely on the adjustment of industrial structure,to achieve the reduction of total electric power consumption,and finally to achieve structural transformation and green development. References | Related Articles | Metrics

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Research on Cangzhou Science and Technology Talents Policyunder the Strategy of Innovation-driven in the New Era WANG Jing-sheng, ZHAO Li-li, ZHANG Peng 2021, 31(1): 62-66.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.012 Abstract ( )   PDF (204KB) ( )   At present,there are some problems in Cangzhou＇s science and technology talent policy,such as the lack of pertinence to the introduction of high wall talents and the lack of competitiveness of policy content,Cangzhou policy makers and implementers should pay attention to the importance of science and technology talent policies,strengthen the pertinence of policies,and strengthen the competitiveness of policy contents.This paper analyzes the development strategic opportunities faced by Cangzhou＇s scientific and technological innovation,and puts forward some suggestions to formulate and improve the scientific and technological talent policy to promote Cangzhou＇s innovation driven breakthrough,which has a certain guiding significance for Cangzhou to promote the gathering of excellent scientific and technological talents,promote scientific and technological innovation activities,and help Cangzhou regional innovation and development. References | Related Articles | Metrics

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Research on Cooperative Operation Mode of Teaching Reformof Marketing Specialty in Higher Vocational Colleges——Based on Anhui Province Marketing Graduates EmploymentEmpirical Research HU Qi-liang, SU Bo-wen 2021, 31(1): 67-71.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.013 Abstract ( )   PDF (209KB) ( )   The rapid development of the economy and the steady advancement of supply-side reforms require a large number of high-quality marketing talents.The sustainable development of the marketing major in higher vocational colleges is a key factor affecting the training of high-quality skilled talents in the sales industry.Through a systematic analysis graduates from 2012 to 2017 of Anhui Province marketing majors and a questionnaire survey,the deep-seated reasons for the employment problem of graduates are found,and further analysis on the influence factors of“government,bank,enterprise school” on the construction of marketing major is made.Thus,corresponding strategies such as government policy-led coordination,sales industry association-guided coordination,enterprise cooperation guidance coordination,school marketing professional reform coordination and other corresponding strategies are proposed to promote the development of Anhui Province＇s marketing professional. References | Related Articles | Metrics

Basic Science Research

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Remark on the Lower Bound for the Blowup Time of the Solution to a Parabolic Equation WANG Yuan-yuan, HUO Zhi-xin, KONG De-zhi, CHENG Shu-ming, ZHOU Li-jie 2021, 31(1): 72-74+80.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.014 Abstract ( )   PDF (205KB) ( )   In this paper,the lower bound of blow up time for quasilinear parabolic problem is extended to the more general cases with divergence type differential operators and nonlinear terms.By using the idea of lower bound of blow up time for quasilinear parabolic problems and some inequality estimates,a lower bound of blow up time is obtained,and a theorem is given. References | Related Articles | Metrics

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Derivation of the Finite Element Theory of Elasticity with Couple Stress by Tens or Analysis SUN Xiao-yong, SONG Xing-hai, HOU Na-na, FU Jian-hang, LIU Li-yue 2021, 31(1): 75-80.  DOI: 10.16046/j.cnki.issn2096-5680.2021.01.015 Abstract ( )   PDF (314KB) ( )   The classical theory of elasticity expresses infinitesimal deformation by displacement gradient.The rotation of the infinitesimal body is regarded as the rotation of the rigid body without considering the rotation deformation.In the theory of elasticity with couple stress,rotation deformation is represented by rotation tensor.The rotation and translational displacement of the micro element are the same order,while the rotation and strain tensors are the same order.The rotation tensor corresponds to the rotation vector one by one,and the gradient of the rotation vector is used to represent the rotation deformation.The constitutive relation of elasticity with couple stress includes stress-strain relation and couple stress curvature tensor relation.Discrete the displacement of element to nodes by using isoparametric transformation method.Based on the principle of virtual work,apenalty function is added to reduce the demand of higherorder elements in the finite element equation.The finite element theory of elastic lines with coupled stresses to solve the plane problem is derived.The distribution of displacement,stress and strain in the problem of plane can be obtained,and the mechanical evaluation of the structure can be carried out. References | Related Articles | Metrics