bluuebunny/crossref_metadata_2025 huggingface dataset:
A Frequency Measurement Algorithm for Power Quality Monitoring Terminal
Authors: Chen Kaiming , Huang Lvchao , Liu Zhu
Published: November 2020

With the continuous access of high-power electronic equipment, electric vehicles and other loads in the user side, the frequency of power grid fluctuates. As one of the power quality parameters, higher or lower frequency has a negative impact on power system and users. Therefore, the accurate measurement of frequency is of great significance to the State Grid and users. In order to measure the frequency accurately, this paper proposes a frequency measurement method according to power quality monitoring technical specifications issued by the State Grid in 2017. Through the design of band-pass filter to filter out DC (Direct Current) component and high-frequency harmonic interference, along with the improved zero-crossing detection process, aim to judge the whole cycle wave number and its occupation time in ten-second time interval. Matlab is used to simulate the accuracy of the algorithm under different conditions. The results show that the error range measurement of frequency is far less than the accuracy level of class A and S power quality testing equipment. Therefore, this algorithm is feasible in the application of power quality monitoring terminal.
Application of the Automated Control System for Reference GNSS Station Network in the Transport Sector
Authors: Akhmedov D , Moldabekov M , Yeryomin D , Zhaxygulova D , Kaliyeva R
Published: November 2020

Achieving high accuracy by GNSS (Global Navigation Satellite System) positioning is in demand in many industries, including transport, where ensuring the positioning of moving vehicles with an accuracy of 1-3 meters is an essential condition in the development of intelligent systems for monitoring and optimization of road traffic. In this case, the task should be solved in such a way as to be accessible to a wide range of users, and thus be simple and cheap. In this paper, in order to achieve accurate GNSS positioning of a moving car is considered the use of a smartphone, as the most popular navigation device of a typical user, raw data of which is processed by differential correction using the Automated Control System for Reference GNSS Station Network. Positions obtained by smartphone is compared with data obtained by the u-blox receiver. The experiment is conducted in an urban area typical for Kazakhstan. It is shown that using a smartphone as a navigation aid with a further differential correction from one reference station allows positioning with accuracies at least of 1.4 meters.
Design and Development of Automatic Generic Cabling System Based on .NET
Authors: Wei Ying
Published: November 2020

With the development of intelligent building, its infrastructure generic cabling technology was still in the manual stage. In this paper, we analyze the connection between generic cabling technology and CAD. Based on the framework of.NET, we carry on the secondary development of AutoCAD using visual programming language C# to develop the automatic generic cabling system. The system can meet standards of generic cabling project, and realize automatically system diagram design. The system can also generate automatically construction plan design, and complete material statistics, and project budget. It can not only ensure the generic cabling project strictly according to the standard construction, improve project quality and level, reduce the workload of the designer, but also greatly promote the development and application of generic cabling technology in intelligent building.
Research on Key Technologies of Intelligent Industrial Robot System for Bulk Material Transportation
Authors: Yu Jiming , Wu Zhongming
Published: November 2020

With the application of Intelligent Manufacturing in the mining industry, the demand for intelligent and unmanned delivery of Stacking material is more and more urgent. The particle size of iron mineral powder is very small, the surface shape is very irregular, and Acquisition effect affected by absorbing wave, diffuse reflection, signal interference and other factors. The intelligent Industrial robot system has a great challenge in the accurate selection of grab point, which is easy to cause the lower chute and upper rope climbing of grab, and cause the delivery business interruption. Because of the above characteristics of iron mineral powder, it is very difficult to develop an intelligent shipping system with precise collection, intelligent scheduling and automatic shipping technology. At present, there is no systematic, practical and intelligent industrial robot system. After three years of research, the project team has conquered the key technologies of the project, developed the key technologies such as the iron concentrate height acquisition radar, three-dimensional distribution algorithm, and developed the inteligent industrial robot shipping system, which can be applied to the full-automatic delivery of bulk materials in the stacking warehouse. Field test shows that the intelligent system have good effect.
An Algorithm for Extracting Entropy Features from EEG Signals Based on T-test and KPCA and Its Application on Driving Fatigue State Recognition
Authors: Zou Shuli , Huang Peifan , Shangguan Pengpeng , Lin Zhiqiang , Ye Beige , Qiu Taorong
Published: November 2020

In consideration of the nonlinear characteristics of electroencephalography (EEG) signals collected in the research on driving fatigue state recognition, the recognition accuracy and the time performance of the driving fatigue state recognition method based on EEG is still not ideal, we construct a driving fatigue state recognition model and corresponding recognition method by combining t-test with kernel principal component analysis based on EEG entropy features. By applying this method to 30-electrode EEG data, testing it with 7 kinds of classifiers and comparing the results with the results without t-test, we find that the proposed method not only improve time performance, but also has the ideal accuracy. Through selecting the best classifier, the recognition accuracy and time performance are improved.
Adaptive PID Control with Forgetting Factor for Three-phase Asynchronous Motor
Authors: Zhao Ying , Luo Cuihua
Published: November 2020

In order to solve these problems of large overshot and poor stability of the speed-control loop for a three-phase asynchronous motor, one adaptive PID controller is applied. The controller combines least square method with forgetting factor to estimate such PID control parameters, which can adjust PID controller’s parameters in real time even when some abrupt disturbance occurs. The simulation results show that the proposed adaptive PID controller has some advantages, such as fast response, good stability, certain adaptability and robustness, compared with traditional one, and can meet the basic requirements for the speed control of asynchronous motor.
Control Analysis of Resonance System Based on Active Disturbance Rejection Control
Authors: Zhang Yongli , Liu Yu , Yi Guorong
Published: November 2020

The mass-spring-damping resonance system is modeled by the mechanism-method and Lagrange method, and the stability of the system is analyzed. The extended state observer (ESO) algorithm is used to analyze and control the mass-spring-damping system based on active disturbance rejection control (ADRC) theory. At the same time, it is compared with the traditional PID algorithm. Random noise is added to the simulation to simulate the real environment and the results show that the ADRC control algorithm is more ideal for system control.
Vehicle Routing Problem with Time Windows Arising in Urban Delivery
Authors: Cao Can , Zhang Xiangfei , Guo Zhanyuan
Published: November 2020

Delivery is an important part of logistics operation. The way to plan the vehicle route with consideration of the demand, time window and total travel cost will directly affect the operation cost and the efficiency of delivery. In this paper, a mathematical model of the vehicle routing with time windows arising in urban delivery was formulated, and Clarke and Wright saving algorithm was used to solve it. A real case of a company was used to test its performance. The result shows that the Clarke and Wright saving algorithm is more effective than the actual operation of the company.
Flow Field Simulation Analysis of Train Siphon Toilet with Variable Pipe Diameter Based on the Investigation of Siphon Performance
Authors: Yang Songzhi , Zhang Yicheng , Hemida Hassan , Wang Yu , Ren Dejian
Published: November 2020

The performance of siphon toilets in trains with varied pipe profiles were investigated. The profiles of the siphon pipe are varied based on the diameter of the pipe along the pipe length. The flushing process was simulated by using CFD method. The starting time, the duration, the siphon mass flow rate, the negative pressure in the siphon pipe were recorded and selected as siphon performance indexes. The results showed that for the same type of siphon pipe, the siphon performance becomes worse with the increase of the maximum pipe diameter as the minimum pipe diameter is 45mm. The simulation confirms that the performance of the siphon toilet with the pipe diameter varying from large to small then to large is the best; the performance of the siphon with a pipe diameter varying from small to large then to small is the worst. The qualitative results may provide some suggestions for relevant industrial designs.
Research on Anti-collision Method of Trackless Equipment in Underground Mine
Authors: Yu Lewen , Zhan Kai , Zhang Da
Published: November 2020

In trackless transport of underground mines, accidents are much more frequent and serious due to the lack of effective safety warning measures. In this paper, a method of anti-collision for trackless equipment based on lidar was described. The background of the technology was recommended and the characteristics of roadway and data processing method were introduced. The method of processing radar data was proposed and a distance model was built, so the distance judgment method was provided. Finally, the method was applied on a Load-Haul-Dump (LHD) and it was proved that this method had obvious effectiveness and wide application for unmanned LHD in deep mining.
Simulation Analysis of Friction Braking Performance of Electric Hydraulic Block Brake
Authors: Wang Tao , Wang Quanxian , Zeng Xiangyue
Published: November 2020

This article is based on the definition of static friction force in Coulomb friction theory, through the finite element simulation of the friction process of the friction pair model between the electrohydraulic block brake lining and the brake disc, the friction stress of the friction pair under critical radial slip under different radial pressures is obtained. Saint-Venant’s principle and the definition of frictional stress are combined to calculate the corresponding maximum static friction and braking torque. Finally, the braking performance of the brake is affected by the coefficient of static friction, and the law that the coefficient of static friction is affected by environmental factors is further discussed. In this paper, the simulation evaluation of the braking performance of the electric hydraulic block brake through simulation experiments has a certain reference for the evaluation of the friction braking performance of the electric hydraulic block brake.
Dissolving Microneedles for Transdermal Drug Delivery System
Authors: Bai Chenlin , Huo Cheng , Zhang Peiyu
Published: November 2020

There is a remarkable interest in research on dissolving micromachined needles or dissolving microneedle (DM) for transdermal drug delivery (TDD) because the devices with DMs can deliver drugs without leaving potentially dangerous residues of sharps waste after use. DMs encapsulated medications into microneedles built by water-soluble materials. Both drugs and microneedles can dissolve into the human tissues after the needles insert the skin. This paper reviewed the DM technology, including the materials and pathway for TDD, manufacturing techniques, and facing challenges. The materials and the pathways for TDD are described. Micromachining technology has been employed to manufacture dissolving microneedles including micromolding, lithography, and the droplet-born air blowing. Moreover, their challenges are discussed as well. Finally, the development of DMs has been also prospected.
Machine Vision Based Study on State Recognition of Milling Cutter
Authors: Wu Songlin , Xue Shaojun , Ning Ruobing , Zang Yingqi , Zhang Fei
Published: November 2020

As a major cutting tool in machining, the wear state of a milling cutter has a directly impact on machining quality and production efficiency. In order to detect the wear conditions of milling cutter, an inspection platform based on machine vision principle is designed. Hardware arrangement of the platform is introduced and the related equipment is analysed and selected accordingly. The milling cutter clamping device used in the platform is also designed. The collection of the measured milling cutter end image is realized successfully. The image processing methods of worn cutter are studied in detail. Adaptive greyscale adjustment and median filtering are used to decrease the noise in the image. Automatic threshold segmentation and edge extraction based on Sobel operator are also designed to achieve image pre-processing. A series of image processing experiments are carried out. The feature extraction algorithm for worn milling cutter end image is presented. Through comparative experiment, the presented machine vision measurement method is efficient.
Low Dose Mammography via Deep Learning
Authors: Zhu Guogang , Fu Jian , Dong Jianbing
Published: November 2020

X-ray mammography has been widely applied to breast cancer diagnosis due to its simplicity and reliability. However, X-ray will do harm to the health of patients or even cause cancer. Low dose mammography by reducing the tube current is an effective method to reduce radiation dose and has attracted more and more interests. In this paper, we implemented a method to improve the image quality of low dose mammography via deep learning. It is based on a convolutional neural network (CNN) and focuses on reducing the noise in low dose mammography. After training, it can obtain a high quality image from a low dose mammography image. This method is validated with experimental data sets obtained from The Cancer Imaging Archive (TCIA). It will promote the application of state-of-art deep learning technique in the field of low dose mammography.
Refinery Operations Optimization Integrated Production Process and Gasoline Blending
Authors: Li Ming
Published: November 2020

Operations optimization is key element of refinery production. The core production activities are operations of process units and product blenders. Operations Optimization of oil processing and product blending was researched in this paper. Using discrete time presentation, a MILP optimization model was built. By formulating operations of processing units and blending units, materials production and storage, energy generation and consumption, co-optimization of materials processing and product blending was realized. Utilizing the proposed model to optimize production operations of a refinery, simulation results show the formulation’s efficiency.
Research on Multi-objective Optimization Method of Central Air Conditioning Air Treatment System Based on NSGA-II
Authors: Li Xue , Li Shujiang , Jiao Hongyuan
Published: November 2020

In this paper, the composition, working principle and characteristics of the central air conditioning air treatment system are comprehensively analyzed, the energy consumption equipment of the air treatment system is established, the energy consumption model of the chilled water pump and fan is established, and the sum of the energy consumption models of the pump and fan is used as the air The total energy consumption model of the processing system is given, and the constraint conditions of the objective function are given. The characteristics of the evaluation index PMV describing the application of the human body’s cold and hot feeling and the PPD index characterizing the degree of dissatisfaction in the thermal environment are analyzed. The room comfort model with the smallest PPD value is established. Finally, the minimum total energy consumption of the air treatment system and the smallest PPD value are established Established a multi-objective optimization model. The NSGA-II algorithm is used to optimize the established multi-objective function, and the optimal solution set satisfying the two conditions is obtained.
Analysis on Degree of Freedom of Mechanism Based on Characteristics Description of Joint Motion Domain
Authors: Luo Jianguo , Wang Ting , Wang Yuqiang
Published: November 2020

The concepts includes input and output degrees of freedom of the mechanism are distinguished and redefined, The motion domain characteristics of translation and rotation joints can be described by planar six-dimensional topological graph, the output kinematic characteristics of RRPRR series branch chain and 3-RRPRR parallel mechanism are obtained by an example analysis, this new theory and method not only realize the quantitative display of the instantaneous degree of freedom of mechanism for the first time historically. In addition, the detailed process and form of the comprehensive transformation between the input and output motions of the mechanism are revealed historically for the first time and presented in the form of formulas. Theoretical definition and computational analysis method based on the six elements description of moving scope of joint newly proposed, which provides a set of scientific, universal, intuitive and effective theory and method for DOF analysis of arbitrary serial and parallel mechanisms.
Effect of Process Parameters on the Automobile Part in Hot Stamping Process
Authors: Ma Wenyu , Yao Ye , Yang Jianwei , Zhang Jun , Zhang Yongqiang
Published: November 2020

In this study, the influence of variables, including friction coefficient and initial blank temperature, on the formability in the hot stamping process of steel was analyzed. The formability indexes have maximum thickness thinning rate and springback. The friction coefficient is chosen between 0.05 and 0.4. The range of initial blank temperature varies from 825 to 995 °C. The combination of central composite design and response surface method was used to analyze the relationship between the variables and indexes. The maximum thinning rate of the hot formed part increases obviously with the increase of the friction coefficient. The maximum thinning rate increases slightly with the decrease of the initial blank temperature. The springback increases with the decrease of the friction coefficient significantly. The initial blank temperature affects the springback slightly.
Research on the Mechanical and Contact Performance of Marbles Screw Loading Device in Dry Disk Brakes
Authors: Yang Lingling , Ning Keyan , Ren Yiru , Yang Shilei , Ma Xinxing
Published: November 2020

The marbles screw loading device is an important structural part in dry disk brakes. With the increasing of braking load and temperature, the material, mechanical and contact performance become a great challenging for the brake design. To better understand the performance, the mechanical and contact performance of marbles screw loading device is investigated. The performance is investigated under different braking load. Then, the influence of typical parameters including geometrical, friction coefficient and temperature on the effective stress and strain is researched. The explicit finite element method is employed to build the numerical simulation model. Numerical simulation result shows that the contact area centre locates on the outside of the brake. The disc groove with 15°has better performance. The residual stress is an increasing with respect to the temperature for the decreasing of material performance. The marbles screw loading device could be largely improved by adjust the geometrical dimensions.
Damage Factor Analysis of Q235A Steel Based on Acoustic Emission Test
Authors: Cao Shuwen , Chen Chengcheng , Liu Qinlong
Published: November 2020

To analyse the damage of Q235A steel during axial tension, tensile experiments were carried out on several Q235A sheet specimens, the acoustic emission (AE) signals were collected at the same time. The properties of cumulative ringing counts of sheet specimens were analysed during tension process, the load-cumulative ringing counts curves were fitted, and the expression of steel damage factor was obtained by polynomial cumulative ringing counts. The cumulative ringing counts calculated by this expression under different loads are close to the experimental values, which prove that it is feasible to use the cumulative ringing counts of acoustic emission to represent the damage factors of Q235A steel during tensile process.
Design of King Grass Crusher Based on SCM Control
Authors: Li Zunxiang , Jiao Jing , Ou Zhongqing , Liu Xinpeng , Huang Xiaohong , Du Jihua
Published: November 2020

King grass is rich in nutriments and palatable, and has soft and succulent leaves, with high digestibility. It is one of the best green fodders for herbivore livestock and poultry. In the process of breading flocks and herds, the feed cost can be reduced largely by utilizing king grass rationally. King grass needs to be cut and ground for being used as feedingstuff. Conventional manual process consumes a large quantity of manpower and material resources, leads to the reduction of production efficiency, and brings about high labor intensity. In view of this, an automatic control king grass crusher high efficiency and practicability is designed, which integrates cutting and crushing. This machine is based on SCM, which realizes whole-process automatic control and rational coordination of pressure sensor with stepping motor for various movements, and can handle king grass crushing well.
Structural Design of Large Heavy-load Stone Cutting Robot
Authors: Wang Chenglin , Li Chunjiang , Zhao Lijun , Wang Shengxue
Published: November 2020

Large quantities of stone cutting are generally done using robots. The current stone cutting robot drives the cutting machine to move and complete the cutting through the manipulator, but its moving range is limited. In response to this problem, a large heavy-duty stone cutting robot was designed in this subject. According to the design requirements and the functions to be realized by the equipment, the detailed structural design of each component of the stone cutting robot was carried out, and the static analysis of the robot arm and arm was carried out using ANSYS to ensure the safe operation of the equipment. The D-H parameter method was used to establish the kinematics model of the stone cutting robot, the positive kinematics equation was obtained by using the homogeneous transformation matrix, and the inverse solution of the kinematics equation was combined with the algebraic method. The proposed design was reasonable through experiments.
Development of a High-precision Digital Display Torque Wrench
Authors: Xu Jian , Zhao Yinming , Chen Kexing
Published: November 2020

Thread connection is widely used in mechanical connection. Torque wrench can feedback tightening torque in real time, and can apply more accurate tightening torque, which is widely used in engineering. Some assembly lines in aerospace or military field the tightening accuracy need to reach 0.1%, comparing with the only 1% accuracy of ordinary working wrench, the high precision torque wrench is needed to apply the high accuracy torque in aerospace or military field. Two methods are introduced to improve the measurement accuracy of the torque wrench. One is to design the transducer with pure torsional transformation when it is used. The other is to apply linearity correction to the transducer by circuit software. The results shows the accuracy of the torque wrench is 0.1%, which is much higher than ordinary work wrench.
Design of Detection Probe for Weak Radioactive Substance
Authors: Yang Bin , Zhao Hongtao , Li Yan , Li Gang , Wu Peng
Published: November 2020

In order to improve the detection efficiency and sensitivity of the detector for weak radioactive substances, a detector probe has been designed which with double photomultiplier & NaI (Tl), by using of multi pulse coincidence measurement and energy spectrum recognition algorithm to realize the fast detection of weak radioactive substances. Through the amplification factor, data calibration and detection threshold experimental research and data comparison found that, the detection efficiency and sensitivity of the detector for weak radioactive substances are improved, this also proves the effectiveness of the design of detection probe.
Optimized Design of FIR Filter Based On FPGA
Authors: Fu Qihui , Zhang Guoqin , Wu Xiushan , Yan Shubin
Published: November 2020

Based on the field programmable gate arrays (FPGA), a low area and high speed FIR filter is proposed and designed. The multiplication modules were replaced by adders and shift registers in the proposed architecture. This is possible because a coefficient approximation is performed, using the algorithm that computes the coefficients like a sum-of-powers-of-two (SOPOT). Compared with the traditional method, the area of the 7-tap 12 bit FIR filter occupied is 75%smaller.
An Improved Defect Detection Method of Water Walls Using the WGAN
Authors: Zhang Yu , Lu Li , Wang Yuwei , Ding Yongsan , Yang Jia , Xu Zhongfeng , Ma Bo , Lin Xiaoyong
Published: November 2020

This paper proposes an improved water wall defect detection method using Wasserstein generation adversarial network (WGAN). The method aims to improve the problems of poor safety and high level of maintenance personnel required by traditional inspection methods, and improve the accuracy and safety of water wall defect detection through automated inspection. The WGAN is used to expand the water wall defect data. Then the extended data set and the original data set are loaded into a convolutional neural network for training, respectively. The results show that the accuracy of the expanded data set is significantly improved, which can achieve the industrial requirement of the thermal power generation.
A Fast Calculation Method for Bus Body Based on Equivalent Stiffness Element Method
Authors: Huang Xinshen , Li Hao , Zhang Zhenkun , Zheng Jianguo , Pei Hailong
Published: November 2020

In view of complex modeling and inefficient calculation at existing stage finite element analysis method in bus body skeleton analysis. This paper presents a method on simulating complex large section beams by equivalent stiffness element. Equivalent stiffness element model is analyzed theoretically. Experiments are carried out to verify that the equivalent stiffness element method can be used in rapid analysis and calculation for girder, body frame and body optimization. It not only reduces modeling complexity, but also improves calculation efficiency. To a certain extent, it can provide a better analysis method for large-scale vehicle modeling and simulation.
Vector Kinematics Modelling and Simulation Analysis of Half-rotating Walking Mechanism
Authors: Wang Yongming , Ma Tengfei , Xu Xuetan
Published: November 2020

In order to solve the stability problem existing in the robot mobile system based on the two-stage half-rotating mechanism, a swing balanced configuration is proposed. Combining the vector method and the D-H method, a forward kinematics modelling and analysis method for the half-rotating walking mechanism is proposed. First of all, using vector kinematics, according to the characteristics of the walking mechanism, combined with the D-H method to establish the relevant coordinate system and the transformation matrix between each coordinate system, derived the position vector, angular velocity vector, linear velocity vector and other relevant kinematic characteristic expressions of the key points of the mechanism, and calculated in MATLAB software to get its theoretical analytical curve. At the same time, the kinematics model of the half-rotating walking mechanism is established in the ADAMS software, and the ADAMS simulation results are compared with the theoretical analysis results. The two are basically consistent, which verifies the correctness of the forward kinematics modelling method of this half-turn walking mechanism.
Experimental Study on Shear Behavior of Reinforced Autoclaved Aerated Concrete Slab
Authors: Zhang Tianjun , Dai Jinzhen , Qin Shihong
Published: November 2020

Process two-points concentrate force load shearing trial for 6 ALC plates (Autoclaved aerated concrete reinforced plate), the article introduced the trial specimen structure, trial device and load scheme. This trial obtained the influence of the shear capacity of ALC plate like failure mode, load-deflection curve, stress (varying) distribution, steel types and shear span ratio. The research shown that: ①The reinforced ALC plate easily form the strong bending and weak shearing members, happen shear pressure failure when designed shear span ratio X=2.5, happen diagonal-tension failure, when designed shear span ratio X>5; ②If the oblique crack position close to the anchoring gusset or pass through anchoring section then maybe weaken the anchoring force and reduce the shearing strength of plate. Because of its brittle nature, anchorage failure must be avoid. Sufficient anchorage can theoretically be provided either by bond or by cross bars welded to the longitudinal reinforcement. ③For the calculation method of the shear bearing capacity of ALC without shear reinforcement with high strength longitudinal steel reinforcement, the technical code for the application of autoclaved aerated concrete in building in China is no longer applicable, EU standards calculated result are all less than the measured values, the method of international RILEM materials association is more suitable and the calculated value more close to the measured value.
Research on a New Type of Antifriction and Antiwear Cutting Fluid Based on Superlubricity Theory
Authors: Yang Yong , Li Jindong , Li Ang
Published: November 2020

Based on the superlubricity theory, a new type of cutting fluid with excellent anti-friction and anti-wear effects is developed. Using the existing superlubricity agent, several new environmentally friendly water-based cutting fluids have been formulated; Further, the high-speed cutting tests of a new type of cutting fluid were carried out for titanium alloy. Finally, a large number of comparative analyses were performed based on the test results. Studies have shown that the friction coefficient obtained using the cutting fluid with solid lubricant is generally large, however, the lower friction coefficient can be obtained when using the cutting fluid with glycerol-acid and hexadecyl dimethyl ammonium bromide, also the better cooling and lubricating effects were obtained.
Lost Circulation Mechanical Model and It’s Application in Permian Igneous Rocks in Shunbei Oilfield
Authors: Liu Shiyin , Li Shaoan
Published: November 2020

The Shunbei Oilfield is a major discovery of Sinopec in the ultra-deep marine carbonate rock field, and it will become the main battlefield for Sinopec to increase reserves and production. At present, the exploration and development of the Shunbei Oilfield is mainly concentrated on the No. 1 and No. 5 fault zones in the Shunbei area. Due to the complex geological structure, there are a series of drilling technical problems in drilling. Lost circulation will not only lose drilling fluid, produce non-productive time and affect drilling safety, but also limit drilling speed, which is one of the most headaches and difficult problems in drilling. To this end, scholars at home and abroad have carried out a lot of research and exploration, and developed a series of leak-proof and plug-in devices such as non-penetrant, elastic graphite, Form-A-block, fiber cement, water-absorbing resin, thermosetting resin, gel and chemical consolidation. Materials, and formed a variety of supporting process technologies. Granular, fibrous, and sheet composite bridging materials are most commonly used on the site, but ordinary bridging materials are resistant to temperature differences, easily carbonized at high temperatures, and the width of underground cracks needs to be clear when plugging, non-penetrants prevent Lost circulation of microfracture formations. It has poor leak-proof effect on large cracks, because of its low strength, expansion materials such as water-absorbent resin are better for plugging, but the pressure-bearing effect is poor, foreign Form-A-block and Chinese DTR are equivalent High water loss materials have good adaptability to cracks, but the pressure is generally low, fiber plugging methods such as fiber cement and thermosetting resin are complicated in process, high in risk and high in cost, gel plugging technology has good adaptability to plugging, but withstands temperature differences If it is not combined with other materials, it is easy to leak again in the later period due to the decrease in gel strength, chemical consolidation plugging technology has a high success rate in plugging, but the plugging construction time is relatively long. In summary, although great progress has been made in leak prevention and plugging technology at home and abroad, there is less research on igneous rocks, and it cannot meet the needs for leak prevention and plugging in igneous rock formations. Therefore, it is necessary to analyze the second Shunbei Oilfield in depth. Lost circulation characteristics of igneous rocks in the Mesozoic and the difficult points of preventing Lost circulation and plugging. Develop effective materials for preventing and plugging Lost circulation to improve the effect of preventing and plugging.
Investigation for the Thermodynamic Polarization Degradation of the BaTiO3 Crystal Thin Films
Authors: Han Yue , Sun Na , Sun Degui
Published: November 2020

According to the latest development of memory, it is found that the motion of ferroelectric domain wall is very important for the high-density non-volatile devices of ferroelectric materials. This paper mainly studies the microstructure of barium titanate (BaTiO3) crystal films with the molecular dynamics of crystal domain motion and then models the polarization degradation with the conservation of the nucleation energy-focusing and free energy thermodynamic processes in the crystalline domains. First, by the means of XRD diffractometer and JADE software, the crystal axis orientation of BaTiO3 thin film is analysed, and then the crystal axis orientation is determined by referring the published measurement results. Further, for the ferroelectric crystal BaTiO3 thin film, the thermodynamic process is studied and the temperature dependences of the polarization ratio with respect to the spontaneous polarization is modelled. Numerical simulations have shown the much higher temperature dependence on the nucleation energy than on the free energy in a domain wall system, leading to the possibility to reach a high polarization ratio with the optimal deposition conditions to control the local energy and the nucleation energy cost of crystalline domains.
Research on Force Performance of Assembled Frame Beam
Authors: Li Zhe , Hu Yandong , Zhao Chuanzhi , Qiao Chengyuan
Published: November 2020

Three full-scale specimens of prefabricated frame tongue-and-groove beams connected by high-strength bolts were tested under low-cycle reciprocating loads. The failure patterns, hysteresis characteristics, skeleton curves, ductility of specimens, stiffness degradation and energy dissipation capacity of the assembled specimens were studied and compared with the full-scale ordinary concrete specimens. The test results show that the new form of connection is basically in line with the mechanical behavior of the ordinary concrete specimen, and it is feasible to apply it to the prefabricated frame structure. The test explores the influence of the thickness of the connecting steel plates on the mechanical performances of the prefabricated specimens, and find that the both sides connecting steel plate are more beneficial to the underside plates. In addition, in the design, reasonable selection of bolt and aperture size, the control of the machining error of the specimens, the effective connection of the steel bars jointied of laminated layer can further improve the installation efficiency and seismic performance.
Study on the Influence of Compressibility on Pressure Fluctuation Characteristics of Pump Turbine
Authors: Liu Jianshu , Cao Yang
Published: November 2020

In order to study the characteristics of pressure distribution and the influence of compressibility factors on pressure fluctuation of pump turbine under the condition of turbine. Based on RNG k-ԑ model, aiming at a pump turbine model, this paper uses UG NX10.0 software to build a three-dimensional model, and uses ICEM-CFD software to devide the mesh. Using ANSYS-CFX software, the unsteady simulation calculation of the whole flow passage under the opening of 10 mm movable guide vane is carried out, and the frequency spectrum of pressure fluctuation is obtained by using the fast Fourier transform. After analysis, the dynamic and static interference between the movable guide vane and the runner, as well as between the runner and the draft tube, has an impact on the pressure fluctuation in the front of the runner behind the guide vane and in the draft tube. There is a secondary peak at 9fn. Considering the compressibility, the amplitude of the fluctuation decreases, but the flow is more complex and the pressure fluctuation is more chaotic.
Research on Abnormal Grain Growth in the Conventional Sintering of (K0.5Na0.5)NbO3 Nano Powders
Authors: Chu Dongliang , Wang Chao , Luo Fengjun , Zhu Mankang
Published: November 2020

About 30nm grain sized (K0.5Na0.5) NbO3 powders were used as the raw materials, and the solid phase method was used to prepare potassium sodium niobate ceramics at 750~ 950°C under normal pressure sintering. The abnormal grain growth (AGG) at process of powder sintering was investigated. The consequences demonstrate that when the sintering temperature is greater than 850°C, AGG can be clearly observed. As the sintering temperature increases, the number of areas where abnormal grain growth occurs increases as well as the size. When the sintering temperature is 950°C, the area of abnormal grain growth has a maximum of approximately 1mm × 1mm, and it has good (111) orientation. The difference in the sintering driving force caused by the size distribution in the potassium sodium niobate nano powder is the root cause of abnormal grain growth.
Research on the Coordinated Development of Urban Resilience and Urbanization Level in Sichuan Province
Authors: Ma Ke , Zhang Tianxu , Wei Yali , Zeng Fan
Published: November 2020

Urban resilience can reflect the city’s ability to cope with crisis and risks, and it is an important guarantee for urban sustainable development. In the process of urban development, attention should be paid to coordinating with urban resilience construction. Taking 21 cities and prefectures of Sichuan Province as the research objects, this paper constructs the evaluation system of urban resilience from the aspects of economy, infrastructure, ecology and society, and the evaluation system of urbanization level from the aspects of population, land and economy. By using Entropy Method, the Coupling Coordination Degree model, coupling coordination between urban resilience and urbanization level is discussed. According to the results, the urban resilience level of cities and prefectures in Sichuan Province presents a pattern of “one city is quite high and the rest are low”, and the urbanization level presents a pattern of “one city is quite high, a few are high and the rest are low”. The coupling coordination degree of most of the cities and prefectures in Sichuan Province are low, and the cities with high coupling coordination are concentrated in Sichuan Basin. Combining with the urbanization level and coupling coordination degree, the cities and prefectures are divided into four types, high-high, high-low, low-high and low-low, in this paper. Corresponding development ideas are put forward so as to provide ideas and suggestions for the coordinated development of various cities and prefectures in Sichuan Province.
Research on Flexible Management of Expressway Construction Schedule
Authors: Han Min-Hui , Ni Wen
Published: November 2020

Schedule management has always been the core of expressway construction projects because it guarantees safety and smooth operation for automobiles. This paper introduced techniques utilized in the flexible management of expressway construction projects which were advocated by developed countries in combination with case studies to carry out in-depth research and analysis.
Conceptual Planning and Design of Sponge Campus--Taking the South Campus of Puwan Campus of Dalian Vocational and Technical College as An Example
Authors: Liu Huiqun
Published: November 2020

This article fully understands the goals and requirements of the national guidance to promote the construction of sponge cities. The author fully understands the current situation of research and construction of rainwater management, sponge cities and sponge campuses in domestic and foreign cities. Based on the natural and artificial environment characteristics of the South Campus of the Puwan Campus of Dalian Vocational and Technical College (hereinafter referred to as the campus), this article focuses on the prevention of waterlogging in the rainy season and the collection and utilization of rainwater in the campus, and follows the concept of LID, and proposes a sponge campus “2 principles→4 blocks” →8 sub-items” conceptual planning and design plan. Through the conceptual design of small, source and decentralized control facilities such as permeable pavement, sunken green space, ecological grass ditch, rainwater garden, and underground storage structure, the author constructs a simulation of nature through in-situ collection, natural purification, and replenishment of groundwater.
The analysis of differentiation Between Prefabrication and Modular Construction
Authors: Qin Hua , Yao Yujuan
Published: November 2020

Prefabricated construction and modular construction have been developing many years, and most of the stakeholders agree that both of them have provided a significant improvement to schedule, productivity, quality, safety performance waste-reducing in Architecture, Engineering and Construction (AEC) industry, This study will illustrate the differentiation between modular construction and prefabrication construction from various perspectives, i.e. impact of BIM implementation, influencing factors as well as performance between prefabrication and modular construction.
Research on Energy Saving Design of Steel Structure Residence in Severe Cold Area
Authors: Gong Junhao
Published: November 2020

China has begun to advocate energy saving for the whole people. “Green buildings” have received social attention in large and medium cities. At present, China’s urban central heating is basically at a high energy consumption, high pollution, low efficiency, and extensive level. Most Chinese buildings are non-energy-saving buildings, and the thermal insulation performance of the envelope structure is poor. Over the years, China’s steel production has been ranked first in the world. The light steel structure housing system is currently a relatively environmentally friendly and reliable building system in the world. It has been widely promoted in Europe, America, Japan and other countries, especially in the cold regions of Northern Europe. Extensive use. Therefore, it is imperative to promote the upgrading of the construction industry structure and to use steel as the construction material for light steel fabricated buildings. In this paper, through field investigation and measurement research on prefabricated steel structure residences in severe cold areas, this paper explores an energy-saving optimization system suitable for prefabricated steel structure residences in severe cold areas of Xinjiang, and provides a reference for the design and construction of the energy-saving optimization system for key nodes of this type of residence.
Research on Energy-saving Design Method of Building Envelope in Hot Summer and Warm Winter Area
Authors: Chen Jiating , Liu Yan
Published: November 2020

Since the beginning of the 21st century, with the rapid economic growth, energy pressure has continued to increase, and China’s energy consumption has doubled and become one of the main energy consumers. Building energy consumption accounts for a large proportion of total energy consumption. Therefore, building energy efficiency is the top priority of green building development. By improving the thermal performance of the building envelope, reducing the building’s energy consumption and dependence on artificial cold and heat sources, it has become the current research focus. This paper studies the energy-saving design methods of building envelopes in areas with hot summers and warm winters. It mainly analyzes the energy-saving methods of exterior walls in the envelopes, proposes the development of energy-saving technologies that adapt to local climate characteristics, and concludes the overall building shading structure system is the key to energy-saving design in this area.
Experimental Research on the Dynamic Shear Modulus and Damping Ratio of Marine Structured Clay
Authors: Zang Meng , Li Lu , Wang Weiwei
Published: November 2020

The dynamic shear modulus and damping ratio are essential parameters for the dynamic properties of clay. They play significant role in dynamic analysis of soil mass as well as the safety evaluation on site earthquake. In consideration of the specialty of marine structured clay, the resonant column test was used to analyze the Zhanjiang structured clay. From the result, currently the standard recommended values of shear modulus and damping ratio are not applicable to the marine clay. Therefore, it used the Martin-Davidenkov model along with the empirical relationship of damping ratio and shear strain to build the regularity of the shear modulus and damping ratio versus the changes of shear strain. Consequently it proposed the recommended value of the shear modulus G/G
max and the damping ratio D for the marine structured clay within the strain range of 5×10−6∼5×10−3. The research findings can provide technical foundation for the engineering design, construction and anti-seismic analysis of Zhanjiang structured clay.
Combined Statistical Analysis and Management Measure Optimization of Prefabricated Construction Projects
Authors: Li Chao
Published: November 2020

China’s prefabricated buildings appear increasingly mature in their techniques thanks to the needs of developing green buildings and the impetus of national policies enacted in various levels. Despite that, deficiencies are still common in comprehensive results and management, impeding the further development of China’s prefabricated buildings to a certain extent. This paper conducts an analysis of the project results and a comparative analysis of the combined statistics pertaining to the identically designed prefabricated structures and cast-in-place concrete ones utilized in a residential project based on the method of combined statistical analysis. It is demonstrated that prefabricated buildings prove superior in quality and schedule, and meanwhile have some disadvantages that are also revealed in this paper. The analysis serves as a basis for effective measures of optimizing the management of prefabricated construction projects to be proposed so as to further boost the results of prefabricated buildings.