bluuebunny/crossref_metadata_2025 huggingface dataset:
An intelligent computing and control model of topological relation between spatial objects based on fuzzy theory
Authors: Xiang Jun
Published: June 2021

The technological progress in the field of artificial intelligence (AI) has brought new opportunities and challenges to the intelligent development and innovative research in fuzzy spatial relations, fuzzy theory is the basic theory of intelligent information processing, and the paper gives a brief analysis of fuzzy calculation method in spatial analysis and spatial relation calculation. In particular, the spatial relations of fuzzy objects are more difficult to express and describe accurately. This paper proposes a method to calculate the topological relations between fuzzy objects with 4-Intersection model and 9-Intersection model, in the analysis of spatial relations, the extension from deterministic entity to uncertain entity is realized with fuzzy set theory, the fuzzy space matrix is constructed, then fuzzy topological relations and fuzzy membership are calculated and output, the model simplifies many complex relations, and it can describe eight topological relations including disjoint, meet, overlap, covers, contains, covered-by, inside and equal. In practical application, the position of spatial objects can be controlled and adjusted according to topological relations. Through analysis of algorithm and fuzzy membership calculation, the model is effective in theory.
An Automotive Unknown-Environment Explorer Robot Based on Braitenberg Vehicle Four
Authors: Xu Wenhao , Wang Yibo , Zhang Yuheng
Published: June 2021

Environment exploration is an essential task in robotics, but it requires lots of high-tech sensors, which will make the robot very costly. To complete the exploration, a huge number of robots are required. Then, how to explore an unknown environment using simple robots with simple sensors is a significant problem to be studied. In this paper, robots are built based on Braitenberg Vehicle 4 and the robots are made to explore an unknown environment without a human. Braitenberg Vehicles are a series concept created by V. Braitenberg. Braitenberg Vehicle 4, particularly, is a robot that only has reflection level intelligence. The Robot’s logic is only four parts, going straight, turning left, turning right, and turning around. The simplicity of the design allows putting the Robot into mass production. MATLAB is used to simulate the working process of the Robot to test the Robot’s feasibility. Then, the map drawn by the Robot with the actual environment is compared. The result has shown that the map we got is almost the same as the real surroundings.
Energy Efficiency Hybrid Precoding for UAV Inspection Communication System
Authors: Minzheng Li , Jiaqing Zhai
Published: June 2021

In order to reduce the communication power consumption during UAV power line inspection, a energy efficiency hybrid recoding scheme based on one phase shifter is proposed in its communication subsystem. The solution is realized by using a partially connected hybrid precoder architecture in the UAV communication terminal, and using a beam combiner at the wireless network access point. At the same time, in order to reduce the complexity of hybrid precoding and combiner beam optimization design, convolutional neural networks are used to dynamically design and select the optimized beam required for UAV inspection and communication. Under the premise of efficiency, the communication energy efficiency can be improved as high as possible, thereby effectively improving the battery life cycle and cruise time of the UAV. The simulation results show that, compared with the manifold optimization and orthogonal matching pursuit algorithms, the proposed algorithm can significantly improve the energy efficiency of communication coding and battery life cycle.
A surrogate-assisted hybrid optimization algorithm enhanced by opposition-based learning and its variants
Authors: Ling Zhaoqi
Published: June 2021

Surrogate-Assisted Evolutionary Algorithms (SAEAs) are effective approaches to solve computationally expensive optimization problems by remarkably reducing real fitness evaluations. In this work, we proposed a surrogate-assisted hybrid optimization algorithm via combining a famous hierarchical SAEA Framework ESAO and a hybrid teaching-learning based optimization (TLBO) algorithm TLBO-SM. In addition, opposition-based learning (OBL) and its variants are used to enhance the global search ability. Experimental results on benchmark problems show that our method can outperform state-of-the-art SAEAs on most benchmark problems with the significant enhancement made by a recently proposed OBL variant.
Research on anxiety detection based on personalized data markers
Authors: Tan Yuyang , Zeng Qinwei , Zhang Hongchang
Published: June 2021

The use of machine learning methods to detect human anxiety has become the mainstream. However, the label of current data usually relies on the subject’s manual labeling, and there are strong subjective factors. In addition, traditional methods have the disadvantages of insufficient feature extraction, inaccurate classification results, and insufficient generalization ability. In response to the above problems, we propose an objective data labeling method, which extracts features on the basis of maintaining the characteristics of the original physiological signals, constructs a more complete feature set, and builds a long short-term memory network (LSTM) model on this basis perform an anxiety state detect. Experiments show that after processing the data by our method, the performance of all models has been greatly improved, among which LSTM shows the best performance compared with traditional algorithms.
A 3D medical image registration method based on multi-scale feature fusion
Authors: Zhang Jinshuo , Liu Fangquan , Yu Xuedou , Ma Yingjun , Zhao Xiuyang
Published: June 2021

Deformable medical image registration refers to finding a certain transformation so that the corresponding points of two medical images can be aligned in space. This has important clinical applications. In this article, we propose an unsupervised end-to-end medical image registration method. In this method, the fixed image and the moving image are concatenated in series and input into the convolution neural network to obtain the feature images of different scales. In order to improve the ability of neural network to capture global and local information, we fuse feature maps of different scales. The spatial transformation network uses the deformation field to deform the moving image, so as to realize the registration of the two pairs. We validate our method in the ABIDE data set and compare it with some classic state-of-the-art methods. The experimental results show that our method improves the registration accuracy of image pairs.
Linear correlation analysis of ammunition storage environment based on Pearson correlation analysis
Authors: Yang Qingxi , Kang Qiaokun , Huang Qingyang , Cui Zenghui , Bai Yu , Wei Huanan
Published: June 2021

The problem of the reliability of ammunition storage environment is a hot topic in the field of modern military research, and the key is to find out the main factors that affect the reliability of ammunition sensitive components. Grey relational entropy analysis method can find out the order of influencing factors, but it can’t judge the influence size and correlation. Pearson analysis method can analyze linear correlation factors better. Therefore, this paper proposes that for the complex problems such as the influence factors of ammunition storage environment, Pearson correlation analysis method can be used to find out the linear correlation factors. Then the grey correlation entropy method is used to find out the other factors. It can lay the foundation for the follow-up analysis of the main factors. Through the comparison and analysis of the actual examples, it is found that the ranking of the influencing factors ranking by the two methods has high consistency. But Pearson method can find the linear correlation factors.
Error Evaluation of the Crown Profile of Logarithmic Generatrix Roller
Authors: Yadong Zhang , Jianhua Wang , Hubing Du , Peili Yin
Published: June 2021

In order to realize the accurate assessment of the profile error of the crown of the bearing roller, according to the geometric characteristics and the definition of the shape error of the contour element of the logarithmic bus-type roller, based on the principle of least squares, the least squares piece-wise fitting and error evaluation method of the logarithmic bus-type (combined form of the two-segment logarithmic curve) bearing roller crown profile are studied. Firstly, the three-point method is used to determine the curvature of the discrete data points of the convexity curve, and the boundary point of the two logarithmic curves is determined by the curvature difference method. Secondly, the measuring points adjacent to both sides of the dividing point are selected as auxiliary dividing points; the auxiliary dividing points and the corresponding logarithmic curve segment measuring points are fitted together to fit a series of least squares curves and calculate the corresponding errors. Through comparison and judgment, the least square error of the logarithmic bus-type roller profile is finally determined. Finally, through comparison and judgment, the least square error of the logarithmic bus-type roller profile is finally determined. The example results show that the total error of the logarithmic bus-type roller crown profile curve is 0.0071mm. The method in this paper can effectively realize the fitting and error evaluation of the bearing crown profile error, and it also verifies that the logarithmic prime line can reduce the stress concentration and improve the service life of the bearing.
Research on Evaluation of Tower Vibration State Based on SCADA
Authors: Su Liancheng , Zhu Jiaojiao , Li Yingwei
Published: June 2021

Tower is very critical to the safe operation of wind turbines. In this paper, SCADA data is used to evaluate the vibration state of the tower. A tower vibration correlation analysis method based on denoising autoencoder (DAE) is proposed, which evaluates the impact of state parameters on tower vibration based on the reconstruction residual. The tower vibration is predicted based on the Long Short-Term Memory (LSTM) network, and then the tower vibration state is evaluated based on the Wasserstein distance. The actual SCADA data is used to verify the proposed method. The results show that the method accurately predicts the tower vibration trend and quantitatively evaluates the tower vibration state.
Study on Environmental Adaptability of Electric Vehicle based on WLTC cycle
Authors: Deng Bo , Li Lu , Ou Yang , Wang Yi , Zhao Zhichao , Meng Zaiqiang , Zhou Qianlu
Published: June 2021

By employing the energy-flow testing technique, this study probes into the environmental adaptability of electric vehicles based on the worldwide harmonized light duty driving test cycle. The following conclusions were reached. Compared with the conditions under normal temperatures, the AC system and the PTC consume 18%-20% energy of the battery, the mileage reduces by 32% to 48%, and the energy consumption per 100 km increases by 49% to 81%. From the perspective of single cycles, the total mileage divides into three stages, among which the first stage shows the largest cycle difference. A correction factor is proposed based on the energy equilibrium relations, and the correction factor for the first stage under normal, high and low temperatures are 1.022, 1.050 and 1.184 respectively. Meanwhile, the discharging internal resistance of the battery under low temperatures differs significant from those under high or normal temperatures, showing an increase by 2%-5%, while the charging internal resistance shows no significant differences.
Study on critical speed of three-watt tilting pad bearing-rotor system
Authors: Kongxing Ding , Faxin Zhu , Xianbin Teng , Qijiang Yang , Wenxiang Chen , Zhaojian Wang , Ming Chen
Published: June 2021

By establishing the model of three-watt tilting tile bearing and rotor system and studying the critical speed of three-watt tilting tile bearing and rotor system, the factors affecting its critical speed are obtained. The oil film stiffness coefficient and damping coefficient of sliding bearing and the mass of the counterweight plate added in the mixed bearing supporting rotor system all have a certain influence on the overall critical speed of the system. In this paper, a rotor model was established using DyRobes rotor dynamics analysis software. The critical rotational speed of the three-watt tilting tile bearing/rotor system was investigated by means of the oil film stiffness of the three-watt tilting tile bearing at different rotational speeds and changing the weight of the counterweight plate.
Application of Hydraulic Transmission Technology in Mechanical Manufacturing and Practice of Leakage Control
Authors: Shen Shiying
Published: June 2021

With the continuous development of the machinery manufacturing industry, people’s application requirements and standards for technology are gradually increasing. Many researchers have begun to pay attention to hydraulic transmission technology in machinery manufacturing to avoid new troubles for the development of the entire industry. This article summarizes the application content of hydraulic transmission technology in machinery manufacturing based on previous work experience. The author discusses the leakage control measures of the hydraulic transmission system from four aspects: controlling the leakage of the hydraulic system, strengthening the control of the original seal, controlling the oil pollution, and reducing the shock and vibration probability of the equipment.
Research on the course, form and strategy of autonomous driving competition
Authors: Yang Fenghua
Published: June 2021

Autonomous driving is the future development trend, which will greatly change the way human beings appear and the form of entertainment. Based on the background of the rapid development of autonomous driving technology, this article summarizes the development status of autonomous driving competitions at home and abroad, analyzes the integration of the motorsport industry and the autonomous driving industry, and proposes strategies to promote autonomous driving racing events.
The Design of Automatic Carton Packing System of Tobacco Based on STM32
Authors: Zhai Yuyi , Wang Le , Liu Yunjia , Jiang Tao , Jiang Houyong
Published: June 2021

This article is aimed at the requirements of a cigarette factory’s off-site technical transformation task, and it needs to transfer part of the stem and expanded silk produced by the new factory to the old factory. Therefore, it is necessary to construct a set of fully automatic carton packing system for shredded tobacco to improve production efficiency and reduce labor intensity. The system is divided into mechanical equipment layer, equipment control layer and production monitoring layer. The mechanical equipment layer is the design of the process flow between the various machinery and equipment of the tobacco packing production line; the equipment control layer is based on the STMicroelectronics32(STM32) single-chip microcomputer as the control core, through Modbus The protocol controls each device and performs data transmission, and communicates with the upper computer through the industrial Ethernet and Modbus Transmission Control Protocol(Modbu TCP) protocol; the production monitoring layer is based on the Qt programming tool for interface design and data transmission with the lower computer, and the relevant data is stored in My Structured Query Language (MySQL) In the database. This solution realizes the automation, networking and intelligence of industrial production lines, liberating manpower and improving efficiency.
Design of millimeter-wave chipless tag based on variable angle arc resonator
Authors: Zhang Qianglin , Zou Chuanyun , Jiao Liangyu
Published: June 2021

Faced with the development of miniaturization and compactness of chipless radio frequency identification (RFID) tags, and to reduce the cost of traditional chip tags, this paper proposes a miniaturized, polarization-insensitive, passive, and chipless based on a variable-angle arc resonator. Chipless tags have a high coding density of 44.44 bits/cm2 in the frequency range of 20GHz∼31GHz, and a coding capacity of 4.04 bits/cm2/GHz. The patch on the substrate determines the signature of each resonant frequency, thereby determining the number of identification data bits. To accommodate more data bits and pass barriers between resonant features, the metal patches are orthogonally polarized so that adjacent resonant features will not interfere with each other. As the mm-Waves ultra-wideband (UWB) chipless tags, it can be easily printed on various IoT applications and has great potential for low cost and identity verification. This work makes it easier to implement highly robust, inexpensive, and flexible chipless tags for IoT applications in the mm-Wave band.
Research on a course control strategy for unmanned surface vessel
Authors: Luo Zhigang , Qian Tonghui , Ye Xi , Huang Jiahui , Yu Linwen
Published: June 2021

With the development of intelligent control and modern communication technology, Unmanned Surface Vessel (USV) will soon become another important unmanned platform after drones and unmanned vehicles. Unmanned vessel are easily disturbed by wind, waves and currents during navigation. Solving the problem of unmanned vessel’s course keeping control during navigation has become one of the key technologies in the research of unmanned vessel. Aiming at the course control problem of the unmanned vessel in the course of navigation, this paper firstly carried out mathematical modeling and data analysis on the dynamic model of the experimental unmanned vessel, carried out related design simulations and experiments through the constructed model, and propose an optimal control strategy based on PID controller. On this basis, the accuracy and effectiveness of the control strategy proposed in this paper are verified through a simulation platform, which can ensure the course stability of the unmanned vessel during the navigation process. Key technologies such as UAV obstacle avoidance and coordination provide a theoretical basis.
Control Methods for Quadrotor’s Stability
Authors: Pang Shengyuan , Tian Linzhe
Published: June 2021

Quadrotor unmanned aerial vehicle (UAV) has become more and more popular due to its high maneuverability, vertical take-off, landing and hovering capability, and ease of operation. However, it is subject to various disturbances during the flight, such as turbulence. This paper provides a comprehensive survey of control methods proposed for quadrotor stability. According to the relationship between the controller and the controlled model, this paper divides the quadrotor stability control methods into three categories, namely classical control, optimal control, and intelligent control, for detailed discussion.
Research on Automatic Test Method of Radio Block Center Based on Script Technology
Authors: Zhao Jingjing , Zheng Wei
Published: June 2021

Radio Block Center (RBC) is the wayside core equipment of high-speed railway train control system, which is the key to achieve the safe operation of trains. In order to ensure the correctness of the function of RBC equipment and to send movement authority information to the train correctly, it is necessary to verify the consistency of RBC function with the RBC requirement specification. Therefore, the RBC functional testing is the basis and key to ensure the safety of train operation. The execution of testing cases has a great impact on testing efficiency. How to automatically execute testing cases and fully cover the system specifications is the key issue of RBC functional testing. Aiming at the shortcomings of traditional RBC functional testing, such as low efficiency, long time consuming, huge workload, and low accuracy of fault simulation, by studying the preparation of automatic test environment and the execution of automatic testing cases, this paper proposes a script based automatic functional testing method, and takes the RBC functional testing as an example to verify the correctness and effectiveness of this method. The practical application shows that the description ability of the test script language and the automatic testing environment meet the RBC testing requirements. The timeliness and the safety of RBC functional testing can be improved by using this method.
Characteristics, Connotation and Military Application of Additive Remanufacturing Technology
Authors: Yimeng Fang , Wenhua Wei , Xun Gong , Yadong Li , Xiaozhou Zhao , Qingyan Ma , Tao Xu , Shijun Ni , Zunwu Zhang , Xin Tian
Published: June 2021

This paper analyzes the intelligent and digital trend of remanufacturing industry, discusses the connotation and characteristics of additive remanufacturing technology, compares and analyzes the application status and application technology of additive remanufacturing technology in China’s military industry, points out that additive remanufacturing technology has broad application prospects in national defense science and technology, and brings higher military and economic benefits.
Study on Dry-ice Particle Jet Assisted Decontamination Technology
Authors: Feng Xu , Pan Weihao , Wang Yuhui , Fang Peng , Xing Yingjie , Chen Yang , Song Jinlong
Published: June 2021

Dry-ice particle jet technology, which has the characteristics of no pollution, easy production and high impact, has been widely used in the cleaning of automobile, aviation, printing, electronics and nuclear industry. In this paper, a set of dry-ice jet spraying decontamination device was built. Two types of artificial pollutants, paint and oil contamination were smeared onto the workpieces. The effect of dry-ice particle jet spraying on the paint and the oil contamination was studied comprehensively. In addition, the wettability of the workpieces before and after dry-ice particle jet spraying was tested. The results of this study enrich the technology of industrial cleaning and promote the practical applications of the dry-ice particle jet spraying technology.
Producing various shafts by novel flexible skew rolling in multiple-freedom mill
Authors: Lin Longfei , Wang Baoyu , Shi Jiaai , Ju Zhidong , Wang Jiapeng
Published: June 2021

This paper presents a new method in shafts manufacturing including flexible skew rolling process (FSR), multiple-freedom mill (DRM-80) and a new type of roller, by which can produce various shafts with same rollers via programming different movements. In order to explore industrial application, four typical shafts — preforms of valve and railfrog, the shafts of truck and train were produced in FSR experiments, and their forming defects were summarized and presented.
Study of critical suspension speed of impeller in two paddles stirred kettle
Authors: Chen Yingwu , Xu Hong , Xu Peng , Ren Yanlun
Published: June 2021

Experiments and numerical simulations were used to study the two-layer paddle stirring system. Glass bead particles and aqueous polyvinyl alcohol solution were used as the solid-liquid phases, and the variation of the critical suspension speed of impeller Njs under different parameters was analyzed by testing the parameters of liquid phase viscosity, solid phase particle size, and solid-phase mass fraction. The results showed that the main resistance (surface viscous resistance) increased with the increase of liquid-phase viscosity at particle size d=0.3 and d=0.5 mm, and this factor inhibited the solid-phase diffusion, resulting in an increasing trend of Njs with the increase of liquid-phase viscosity. At particle size d=0.8 and d=1mm, the main resistance (gravity) is not related to the liquid phase viscosity, and the intensity of turbulent pulsation in the kettle is enhanced with the increase of liquid phase viscosity, which is favorable to the solid phase diffusion, and Njs decreases with the increase of liquid phase viscosity. The increase in solid-phase volume fraction increases Njs.
Research on simulation platform of intelligent production lines
Authors: Wang Qinghua , Hu Yanhua , Fu Renxuan , Ma Xinzhou
Published: June 2021

In order to improve the ability of teachers and students to comprehensively apply intelligent production line technology, this paper provides an intelligent production line simulation method and system, which can simulate the operation of intelligent production line, and is easy to control and has lower cost, so as to meet the teaching needs of cultivating intelligent production line application talents. This paper introduces the development technology and implementation method of intelligent production line based on C language of single chip microcomputer.
Design of multi-magnetic couple MR damper with full channel effective damping
Authors: Zhu Yurui , Wang Qun , Ma Jichao , Tang Zhanghong , Yu Yunfei , Li Yongqing
Published: June 2021

A multi-magnetic couple magnetorheological damper with full channel effective damping is designed. By designing the magnetic outer ring of the magnetic couple into a structure with gradual cross-sectional area, the purpose of effective damping of the full channel can be achieved, so that the entire damping channel is affected by the magnetic field. Through the magnetic circuit simulation analysis, the rationality of the design is verified, and the magnetic induction intensity on the damping channel can reach the theoretical design value, which reflects the efficient magnetic field utilization rate of the damper.
Fabric Defect Detection Method Based on Improved U-Net
Authors: Rong-qiang Liu , Ming-hui Li , Jia-chen Shi , Yi-bin Liang
Published: June 2021

Computer vision builds a connection between image processing and industrials, bringing modern perception to the automated industrials. At the same time, defect detection based on deep learning has played an important role in automated detection. In this paper, an improved convolutional neural network CU-Net for fabric defect detection is proposed. In this method, the classical U-Net network was improved. On the basis of network size compression, attention mechanism is introduced and a new compound loss function is used for training. Using the public AITEX defect fabric data set as the test sample, the experimental result shows that the accuracy and recall of the proposed method are 98.3% and 92.7%, respectively. Compared with the highest scores of other detection methods, they are improved by 4.8% and 2.3%, which improves the detection accuracy of fabric defect significantly.
Hybrid data assimilation based on multilayer perceptron
Authors: Lang Jialin , Qiu Feng
Published: June 2021

Data assimilation is widely used in weather forecasting, ocean forecasting, remote sensing observation and other fields. The result of data assimilation directly affects the accuracy of forecasting. Data assimilation algorithms have been studied extensively. The classical algorithms include 3D-Var, 4D-Var, Kalman filter and ensemble Kalman filter. New assimilation algorithms also emerge one after another. In recent years, people have tried to use a hybrid of various data assimilation methods. Deep learning is a hot research field in recent years. Deep learning is able to mine the hidden features of data for analysis and prediction. In this paper, we attempt to use the classical deep learning model-multilayer perceptron to extract the characteristics of traditional data assimilation algorithms to perform hybrid data assimilation. The experiments show that the results of this method are significantly improved compared with the traditional methods, and reveal the value of multilayer perceptron in the direction of hybrid data assimilation.
An object detection research method based on CARLA simulation
Authors: Gao Weihua , Tang Jiakai , Wang Taotao
Published: June 2021

At present, the research of object detection in automatic driving is mainly based on the actual automatic driving vehicle. This method is expensive, less feasible, and difficult to test. Based on CARLA, we proposed an efficient and low-cost object detection method, which can overcome the shortcomings of the actual vehicle research. In this paper, firstly, we obtained images from CARLA, and then the data set is obtained by cleaning and labeling the image. Finally, based on the data set established in this paper, we train the models of YOLOv4, CenterNet and Faster-RCNN respectively, and make a comparative study on the test set. The results show that YOLOv4 has the best detection effect without special optimization method.
Simulation and optimization design of cyclone separator for waste plastic film
Authors: Zhang Q S , Zhang Z S , Yang X H , Yang Z , Yang L Y
Published: June 2021

Waste plastic sorting and recycling is a kind of efficient and energy-saving way of domestic garbage treatment. In this paper, the Cyclone based Multistage Separation Process for waste plastic film is presented, and the principle and structure of cyclone separator are introduced. The fluid analysis software Fluent is used to simulate and analyze the cyclone separator of waste plastic film. The comprehensive analysis shows that the optimal wind speed of cyclone separator is 18m/s, and under this speed the separation effect of particles in cyclone separator is the best. Based on this, the cyclone separator for waste plastic film was optimized, the structure size of cyclone separator for waste plastic film with three different densities was obtained, and the calculation basis for the design and manufacture of cyclone separator for waste plastic film was provided.
Research on the Analysis Method of Engine Assembly Quality Based on Data Driven
Authors: Xin Dou , Jia-li Xu , Jia-jing Wu , Dong-ning Jia
Published: June 2021

In the context of the country’s vigorous development of the industrial Internet, the role of big data has become increasingly prominent. Through the mining and analysis of the value of industrial big data, the efficiency and quality of industrial production will be effectively improved. However, the current research lacks direct quantitative research on the correlation between bolt tightening position data and engine quality. Based on the data of a certain production line of Weichai, the SimpleKMeans clustering and Apriori correlation analysis model for the assembly process data and product quality of a certain type of diesel engine is constructed based on the Weka tool. The mining results of the association rule between the bolt tightening data of the eight stations and the cylinder head vibration peak data show that the cylinder head main bolts, cylinder head auxiliary bolts, camshaft gear bolts and connecting rod bolts are closely related to the cylinder head vibration data, and the confidence levels are respectively 0.78, 0.70, 0.63, 0.52. Therefore, when the engine vibration is abnormal, the tightening data of the cylinder head main bolts, cylinder head auxiliary bolts, camshaft gear bolts and connecting rod bolts are detected first to effectively improve the quality and efficiency of the assembly process.
Research and Application of Quality Control for TC4 Titanium Alloy Profile
Authors: Lei Yu , Baohong Zhang , Dongdong Li , Liangliang Tang , Bingtao Lin , Ning Xiong , Xin Huang
Published: June 2021

Through controlling from the source, TC4 titanium alloy profile ingot heating process surface protection technology and extrusion lubrication process, extrusion die design and manufacturing, profile straightening process, finished product heat treatment process and profile hot bending forming and other key processes have been studied in depth. Technical improvements and quality assurance measures are proposed. The surface quality, shape, size and mechanical properties of the titanium alloy profile meet the requirements of the use of TC4 titanium alloy profile parts for a certain type of launch vehicle. Ensure that the TC4 titanium alloy profile acceptance inspection process is operable. The manufacturing cost of the titanium alloy outer stringer of the launch vehicle is reduced. The quality level and reliability of TC4 titanium alloy outer stringers have been improved.
The survivability analysis and layout optimization of CODOG power system
Authors: Yang Zhang , Qian-chao Liang , Jing-biao Cai
Published: June 2021

The purpose of this paper is to discuss the calculation of the survivability of the CODOG power system in different layouts under the condition that the ship is hit by the simulation technology. In this paper, the impact of the weapon’s hit distribution under the guidance conditions and the layout of different main power compartments on the survivability of the CODOG power system of the ship are discussed, the fuzzy evaluation method is used to evaluate its advantages and disadvantages, and the reasons for the advantages and disadvantages are analyzed.
Study of Thermal Shock Resistance of Plasma Sprayed VW75 Alloy
Authors: Lin Bingtao , Ma Minglong , Zhang Kui , Li Yongjun , Chen Zehua , Zhang Baohong
Published: June 2021

The thermal shock resistance of T5-state VW75 Mg alloy after the plasma spraying was tested, the service process of material under the real environment was simulated, the reasons and mechanism for the coating shedding were revealed, and the comprehensive thermal shock resistance of alloy was acquired. The results showed that before the thermal shock test, the sample surface was flat with the gray color, and after the test was started, the coating surface was turned into white ZrO2 again. As the number of thermal cycles was increased, the black brown color started appearing on the sample surface, and the coating presented the overall shedding after the 158 cycles. The microcracks and pores in the ceramic layer and bonding layer were not developed into macrocracks yet, it could be deemed that the internal bonding at each layer was rather compact, and the coating quality was very high. The failure of thermal barrier coating occurred between the Mg alloy matrix and bonding layer, the thermal expansion coefficient varied from layer to layer of the coating, thus aggravating the interlayer thermal stress and leading to the overall shedding of coating, and in addition, the thickening of thermally grown oxidation layer was also an important cause for the shedding.
Preparation and properties of low temperature fluidity polyether polyol ester antiwear agent
Authors: Zhensheng Yang , Qiutao Song , Guohong Zhang
Published: June 2021

Polyether polyol ester was obtained by esterification reaction with tall oil fatty acid and propoxylated pentaerythritol, and then the viscosity was adjusted by adding a depressant, thus the diesel antiwear agent with better low temperature fluidity was obtained. The structure of the product was characterized by FTIR. The results showed that the esterification rate reached 98.9% when the reaction temperature was 190°C, the reaction time was 3.5h and the amount of catalyst was 4% of the total mass of acid alcohol. After the reaction of propoxylated pentaerythritol with tall oil fatty acid, the fluidity of the product at low temperature was significantly improved, and the product had better anti-emulsification and lubricating properties. When the addition amount was 150ug/g, the spot diameter decreased to 408μm. According to the kinetic analysis, the antiwear molecules are adsorbed to the metal surface through diffusion. On the surface of each iron atom, there are about 1.975×1010 antiwear molecules, forming a protective film with a dynamic equilibrium of adsorption-desorption, thus ensuring the lubricity of diesel oil.
Effect of La-Ce on Microstructure and Properties of 30MnCrNiMo Alloy Steel
Authors: Zhang Mingyi , Gao Ping , Yang Jichun , Geng Wenyuan , Jia Xiaobin
Published: June 2021

The 30MnCrNiMo alloy steel was modified by La-Ce mixed rare earth. The experiment used metallographic microscope, scanning electron microscope and energy spectrum to analyze the improvement behavior of rare earth on the as-cast structure of the alloy steel, the structure after heat treatment, and the morphology of inclusions; a thermal dilatometer was used to analyze the phase transition point, and a reasonable heat treatment process was developed; the effect of rare earth on the mechanical properties of alloy steel at room temperature, low temperature impact and tensile was analyzed. The results show that the 30MnCrNiMo alloy steel modified by rare earth has better refinement of the as-cast grains and the grains after heat treatment, and the size, morphology and distribution of inclusions have been improved. The addition of rare earths improves the impact toughness, especially the low-temperature impact. Compared with alloy steel without rare earth, the toughness can be increased by up to 38%, and the alloy strength has been improved to a certain extent.
Research on Electrochemical Machining Technology of Deep Small Hole using Suction Electrode
Authors: Guorong Sun , Ying Yan , Jintong Dong , Ping Zhou
Published: June 2021

Aiming at the problem of deep small hole machining for difficult-to-machine material, a suction electrode electrochemical machining method is used to solve the problems of slow electrolyte renewal and poor stability during the electrochemical machining of deep small holes. This paper mainly uses the multi-physics coupling software COMSOL to establish a multi-physics coupling model for the electrochemical machining of deep small holes with a suction electrode and simulates the forming process of the deep small hole and the distribution of the flow field and electric field during the machining process. This model verifies the feasibility of electrochemical machining technology of deep small holes using a suction electrode.
The Influence of the Density of CNT Arrays on Their Atomic Oxygen Erosion Effects
Authors: Li Man , Liu Yuming , Li Yu , Yu Qiang , Zhang Yongtai , Liu Chong
Published: June 2021

To investigate the characteristic of carbon nanotube (CNT) arrays with high resistance to the hazardous conditions of atomic oxygen in space environment, the erosion effects of atomic oxygen on CNT arrays with different density have been studied by atomic oxygen simulation equipment. To characterizing the change of the surface morphologies of CNT arrays before and after atomic oxygen exposition, A scanning electron microscope (SEM) analysis method have been used. The SEM images shows that the morphologies of the surface of CNT arrays after atomic oxygen experiment are quite different from those before atomic oxygen experiment. The higher density CNT arrays are etched away more uniformly. The erosion yield of the CNT arrays with higher density is much less than that with lower density, which means that the CNT materials have different atomic oxygen erosion yield. The resistance ability of CNT materials to atomic oxygen is depending on their density.
Electrochemically Etched Superhydrophobic Surface on Aeronautic Steel with Anti-Icing, Self-Cleaning and Durability Property
Authors: Han Yuqi , Liu Ziai , Pan Weihao , Sun Jing
Published: June 2021

The superhydrophobic surface on 30Cr2NiWVA aeronautic steel is fabricated via electrochemical etching and FAS modification. The results of scanning electron microscopy (SEM) show that, after electrochemically etching, the aeronautic surface is covered with rough coralloid-structure film. This surface demonstrates excellent corrosion protection, anti-icing and self-cleaning property. Additionally, this surface shows outstanding superhydrophobicity after anti-icing, self-cleaning test, and even after exposure to the air in the normal ambient environment for two years, proving the durability property of superhydrophobic aeronautic surface. The proposed method is simple and has great potential applications for large-scale applications in aircraft.
Formation Mechanism of Titanium Carbide in Titanium-bearing Blast Furnace Slag
Authors: Guo Yaqin , Liang Duoqiang
Published: June 2021

The formation of titanium carbide (TiC) may result in slag thickening, slag foaming and difficulty in separation between hot metal and slag etc during the blast furnace smelting process with Vanadic Titanomagnetite. Therefore, it is very important to understand and manage the formation of titanium carbide. The formation mechanism of titanium carbide during the reduction process of blast furnace slag - bearing titanium was studied with theoretical calculations and experiments. In the experiment, blast furnace slag - bearing titanium was subjected to 6 hours’ isothermal treatment at temperature range of I300°C-I550°Cin graphite crucible with Ar flow rate of 2L/min (1 atm). The reduced slag was characterized by mineralogical microscope and SEM-EDS detection methods. As a result, the formation of titanium carbide started at a temperature higher than I400°C.
In situ synthesis of metal oxide nanostructures on flexible SiO2 nanofibrous membrane for environmental application
Authors: Wang Hui , Dai Jin , Liu Yi-Tao
Published: June 2021

Formaldehyde (HCHO), as a primary carcinogen, may cause severe health problems in light of its wide applications in the indoor decorations. Nowadays, catalytic oxidation proves to be the most promising method to remove HCHO. By virtue of its environment-friendly and cost-efficient advantages, manganese dioxide (MnO2) has attracted enormous attention in HCHO removal. In this work, flexible silica dioxide (SiO2) nanofibrous membrane (NFM) was fabricated by an electrospinning technique and MnO2 nanoparticle was successfully loaded on SiO2 (MnO2@SiO2) nanofibrous membranes (NFMs) through liquid phase synthesis. Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) were used to characterize the material. MnO2@SiO2 NFMs exhibited great catalytic oxidation activity for HCHO. This research provides a simple and effective method for the development of transition metal oxides (TMOs) for HCHO degradation at room temperature and the composite MnO2@SiO2 material is expected to be used for air purification.
Preparation and NRR application of transition metal nanosheets on carbon nanofiber membranes
Authors: Huang Shengmei , Zhang Meng , Liu Yi-Tao
Published: June 2021

Electrocatalytic Nitrogen Reduction (NRR) is a green and sustainable method of artificial nitrogen fixation, but it is still a serious challenge due to the lack of efficient and selective catalysts. In this paper, carbon nanofiber membranes (NFMs) were prepared by electrospinning technology as the skeleton structure of electrocatalytic materials, and Sn doped MoSe2 nanosheets on carbon NFMs (Sn doped MoSe2@C NFMs) were synthesized by a one-step hydrothermal synthesis method. Compared with pure MoSe2@C NFMs, Sn doped MoSe2@C NFMs will create vacancies, increase the reactive sites of the NRR catalyst, and make Sn doped MoSe2@C NFMs have better ammonia yield (1.61 × 10−10 mol s1 cm−2) and Faraday efficiency (14.51%). This research provides a new idea for designing the structure design of NRR catalyst.
Effect of Order-Disorder Transition on Thermal Conductivity of Gd2Zr2O7 Ceramics
Authors: Ji Yarou , Shi Jinglin , Feng Hanghang , Wei Yitong , Qu Zhixue
Published: June 2021

Rare earth zirconates have been considered as promising candidates for thermal barrier coatings, with extremely low thermal conductivity which is usually attributed to their unique pyrochlore/fluorite structure. In order to investigate the different influence of pyrochlore and fluorite structure on thermal conductivity, Gd2Zr2O7 ceramics with pyrochlore and fluorite structure were prepared separately by controlling the sintering temperature, and the thermal conductivities of the samples sintered at different temperatures were measured and investigated. The results show that the structure of Gd2Zr2O7 changes gradually from pyrochlore to fluorite as the sintering temperature increases from 1450°C to 1600°C, accompanying with a thermal conductivity decreasing first and then increasing. The minimum value of thermal conductivity appears on the sample with pyrochlore structure nearby the phase transition temperature range, rather than that with fluorite structure. Other than the transition of structure, structural distortion in the lattice approaching phase transition may lead to a distinct decrease of thermal conductivity.
Experimental and numerical study on debonding damage propagation of brazed titanium alloy honeycomb under fatigue load
Authors: Bai Ruixiang , Guo Zhenfei , Zou Jianchao
Published: June 2021

In this paper, the fatigue damage propagation of honeycomb structures under three-point bending fatigue load is studied by experiment and numerical simulation. Firstly, the three-point bending fatigue experiment of honeycomb structure with prefabricated damage was carried out, and the length of interfacial debonding with loading cycle was studied. Then, the damage propagation model of honeycomb structure is established based on VCCT theory and Pairs formula. The results show that the numerical results are in good agreement with the experimental results. The numerical model was validated.
Synthesis, Crystal Structure and Insecticidal Activity of 2-(3-Bromo-1-(3-chloropyridin-2-yl)-1H-pyrazol-5-yl)-6,8-dichloro-3-methyl-2,3-dihydroquinazolm-4(1H)-one
Authors: Cong Yun-Bo , Jiang Ai-Zhong , Cheng Chun-Sheng
Published: June 2021

The title compound 2-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazol-5-yl)-6,8- dichloro-3-methyl-2,3-dihydroquinazolin-4(1H)-one (compound 10) was synthesized using 2,3-dichloropyridine as the starting material via nine-step procedures. Its structure was characterized by 1H NMR, 13C NMR, MS, and single-crystal X-ray diffraction. The target compound 10 showed excellent insecticidal activity (100% mortality at 1ppm) against Plutella xylostella.
Analysis of bending stiffness of honeycomb sandwich structure filled with foam
Authors: Wei Changlong , Bai Ruixiang , Bai Heshan , Wang Tao
Published: June 2021

Based on the knowledge of material mechanics and elastic mechanics, the theoretical calculation formula of bending stiffness of honeycomb core filled with foamed rubber is derived in this paper. The rationality and feasibility of the theoretical formula are verified by finite element analysis of three-point bending model of honeycomb sandwich structure with or without foamed rubber. At the same time, the relative error between the bending stiffness value of finite element analysis and the theoretical value is controlled within 10%, which makes the calculation formula of theoretical value of filled foamed rubber honeycomb core have certain reference significance and application value.
Onlay-graft of 3D printed Kagome-structure PCL scaffold incorporated with rhBMP-2 based on hyaluronic acid hydrogel
Authors: Ku Jeong-Kui , Lee Kang-Gon , Ghim Min-Soo , Kim Young-Kyun , Park Sang-Hyug , Park Yongdoo , Cho Young-Sam , Lee Bu-Kyu
Published: June 2021

The onlay-graft, one of the most difficult graft conditions, is used for diverse clinical conditions, including plastic and dental surgery. The graft should withstand continuous pressure from overlying tissues and have excellent bone formation capability in a limited bone contact situation. We recently developed a 3D printed Kagome-structured polycaprolactone (PCL) scaffold that has a stronger mechanical property. This study evaluated the clinical feasibility of this scaffold for onlay-graft use. The value of the scaffold containing recombinant human bone morphogenetic protein-2 in a hyaluronate-based hydrogel (rhBMP-2/HA) to enhance bone regeneration was also assessed. 3D-printed Kagome-PCL scaffolds alone (n= 12, group I) or loaded with rhBMP-2/HA (n= 12, group II) were grafted using a rat calvarial onlay-graft model. Following sacrifice at 2, 4, and 8 weeks, all 3D-printed Kagome-PCL scaffolds were accurately positioned and firmly integrated to the recipient bone. Micro-computed tomography and histology analyses revealed a constant height of the scaffolds over time in all animals. New bone grew into the scaffolds in both groups, but with greater volume in group II. These results suggest the promising clinical feasibility of the 3D-printed Kagome-PCL scaffold for onlay-graft use and it could substitute the conventional onlay-graft in the plastic and dental reconstructive surgery in the near future.