bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot Deformation Behavior of Ni-Modified Graphene/2024 Al Matrix Composites
Authors: Gu Xulong , Liu Fengguo , Kou Ying , Lou Changsheng , Zhang Weiqiang , Lv Xiao
Published: March 2023

The 0.5 wt.% Ni-modified graphene/2024 Al matrix composites were formed by hot compression at the temperature(T) was 300-450 °C, the strain rate(

ε
˙

) was 0.001-1 s−1. The influence of T and

ε
˙

on the flow stress(σ) behavior of the composites was analyzed. Moreover, the metamorphic activation energy of the composites was deduced from the stress-strain data, and the Arrhenius constitutive equation relation of the composites was constructed. According to the dynamic model, the hot processing maps of composites were calculated and analyzed. The Arrhenius constitutive equation of the material is established and the Q is 222.22951 KJ/mol by the peak stress. According to the hot processing maps, the hot instability region of the hot deformation in the experimental parameter interval is determined. Furthermore, the optimal machining interval parameters of the material are proposed to be the

ε
˙

of 0.011-0.368 s−1, the hot working T of 420 - 450 °C.
Numerical Simulation of the Effect of Catalyst on Explosives Detonation Performance
Authors: Wei Dongxu , Wei Li
Published: March 2023

Previous studies on the effect of the blast shock wave are mainly based on experiments. However, due to the extremely short duration of the blast shock, usually within several dozen milliseconds, the blast shock wave will have gone from peak to zero, causing a significant impact on the accuracy of experimental results. In recent years, numerical simulation has become an important method to study the effect of the blast. To study the influence of catalysts on the combustion performance of explosives, this paper intends to study the effect of catalysts on the combustion and explosion performance of pyrotechnic explosives. ANSYS workbench finite element analysis software was used to establish a pyrotechnic-rock blasting model to simulate the different effects produced by different catalysts during the combustion of explosives and compare their blasting effects. It is expected to obtain the preparation technology of higher performance nano-combustion catalysts, good performance nano-combustion catalyst system and its microstructure on the catalytic law of energy-containing materials, and to lay an important theoretical foundation for further development of new varieties of fire explosives with excellent comprehensive performance.
Clay-free biodiesel-based drilling fluid suitable for high temperature
Authors: Shi He , Ni Xiaoxiao , Zhang Jiaqi , Cheng Rongchao , Yan Lili , Wang Jianhua , Liu Rentong , geng Yuan
Published: March 2023

This paper introduces the formation of a clay-free biodiesel-based drilling fluid system. The system uses the biodiesel derived from the transesterification between soybean oil and methanol as the continuous phase, which is environmentally friendly and has an appropriate flow state. In order to inhibit the hydrolysis of the base oil under high temperatures, a small amount of methanol is retained and Lime addition is minimized. Besides, the system also contains a special polyamine-typed rheological modifier instead of organoclay to provide a fragile gel-structure with lower plastic viscosity and higher yield point, thus good for hole cleaning and solid suspension while keeping a higher rate of penetration (ROP). In order to strengthen the plugging and fluid loss control abilities, superfine calcium carbonate and oxidized asphalt are added and obtain a good outcome. Evaluation results showed that the clay-free biodiesel-based drilling fluid exhibits good properties of rheology, filtration, and emulsion stability, with temperature resistance over 200°C, which is suitable for the exploration of unconventional oil/gas restores.
Pulsation Test and Analysis of Internal Gear Pump Used in Electro-hydraulic Actuator
Authors: Tian Yanquan , Zhang Yuqiang , He Jun , Ma Desen
Published: March 2023

The linear conjugate internal gear pump is widely used in the Electro-hydraulic Actuator (EHA) system because of its high efficiency and low noise, especially in the ship domain where vibration and noise requirements are very strict. To find out the reason, the calculation method of flow fluctuation and pressure pulsation at the pump outlet is obtained theoretically. First, the method of obtaining the two characteristic values of pump source flow pulsation Qs and pump source impedance Zs, and the data calculation and processing program are compiled by Matlab. Then the test platform was built, as well as the computer simulation and data collection. According to the theoretical method, the actual flow fluctuation and pressure pulsation at the pump outlet under different working conditions are measured and calculated respectively. The data of each working condition can be summarized and analyzed as: the test platform is reasonable and the data obtained from the test and calculation are reasonable; under the same frequency spectrum, the amplitude corresponding to the fundamental frequency of the motor pump is much larger than that of the pump tooth; under different working conditions, the variation trend of flow fluctuation and pressure pulsation corresponding to the fundamental frequency and the frequency doubling of the internal gear pump is obtained by testing; the specific values are smaller and suitable for the use in a silent system.
Preparation of ZSM-22 zeolite and its application in hydroisomerization dewaxing of lubricating oils
Authors: Dai Jianbing , Wang Junyang , Liu Zhao
Published: March 2023

Hydroisomerization dewaxing is an advantageous process to improve lubricating oil quality. The bifunctional catalyst used in the hydrogenation isomerization reaction provides the isomerization function with the acidic site supported by molecular sieve, and the precious metals such as Pt and Pd provide the hydrogenation function for the metal site, which has the advantages of high activity, low production cost, and mature synthesis process. The ZSM-22 zeolite was hydrothermal synthesized using 1,6-diamino hexane (DAH) as templates in the presence of the seed, XRD, N2 adsorption-desorption and NH3-TPD Cha adsorption-desorption times. Finally, the hydroisomerization dewaxing performance of the Pt/ZSM-22 and Pt-Pd/ZSM-22 bifunctional catalysts were investigated on a high-pressure fixed-bed hydrogenation reactor. The results show that the hydroisomerization dewaxing performance of the Pt-Pd/ZSM-22 catalyst is better.
Preparation of Sm2Zr2O7 Slurry for Thermal Spraying
Authors: Hao Hongrui , Li Yang , Zhang Qingmeng , Song Xiaoyun , Liu Mingkun , Du Yongbo , Deng Hongwei
Published: March 2023

The orthogonal experiment with three factors and three levels was designed to control the process conditions in the thermal spraying process. The solid content, pH value and PVA addition on the stability and fluidity of sm2zr2o7 slurry at different levels were studied. The stability of sm2zr2o7 slurry was characterized by sedimentation experiment, and the fluidity of sm2zr2o7 slurry was detected by rheometer. It was determined that the solid content had the greatest influence on the properties of sm2zr2o7 slurry. The addition of PVA had the least effect. The optimized sm2zr2o7 slurry is as follows: solid content 50%, pH value 7 and PVA addition 4%.
Temperature field analysis and structure redesign of fiber optic gyroscope
Authors: Wang Zishuai , Song Yanming , Chen Lijuan , Zhang Wen
Published: March 2023

Taking the fiber ring of the core device of the fiber optic gyro as the research object, the temperature field simulation analysis of the fiber gyroscope was carried out by ANSYS finite element analysis software, and the structural optimization of the fiber gyroscope was carried out, which effectively improved the temperature field distribution uniformity of the fiber optic ring and reduced the overall thermal equilibrium temperature and time when the fiber gyro reached stability.
Synthesis of Mixed phase TiO2 particles by using the Microfluidic Method
Authors: Wu Zhang , Yanhui Hua
Published: March 2023

Mixed-phase TiO2 finds numerous applications in various fields. Herein, we proposed a controllable approach to synthesize Mixed phase TiO2 particles. The experimental results showed that the particle size of water and titanium dioxide nanoparticles gradually increased with the increased carbon tetrachloride injection rate. The water and titanium dioxide particles transformed into anatase and rutile after calcination. The increase in calcination temperature benefits the formation of a rutile image, and the extension of calcination time benefits the growth process of the rutile phase.
Research of Fault Diagnosis of Mine Rolling Bearing Based on Time-Frequency Analysis
Authors: Li Dong
Published: March 2023

Considering the shortcomings of traditional time-domain and frequency-domain analysis in processing non-stationary signals, this paper proposes to introduce time-frequency into the analysis of a one-dimensional vibration signal and transform it into a two-dimensional time-frequency image to obtain more abundant diagnostic information. At the same time, considering the problem of noise interference under complex working conditions, wavelet denoising is used to preprocess the signal, and the simulation signal is defined. The method of obtaining the time-frequency image verifies the denoising effect. Finally, through the public test data, it is proved that the method can effectively obtain reliable time-frequency images for further bearing fault diagnosis research.
Research on Typical Pipeline Design Method of Power Transmission Auxiliary System based on Vibration Control
Authors: Shu Chenglong , Yan Ming , Wang Chao , Sun Yang , Du Fu , Chen Qidi
Published: March 2023

The power transmission auxiliary system is a set of key systems of armored vehicles, which roughly includes a heat dissipation system, a lubrication system, a compressed air system, a heating system, a thermal smoke screen system, and other subsystems. It is characterized by relying on a pipeline connection so that the auxiliary system and the engine, and the transmission system form a closed loop to achieve functional output. The pipeline of the auxiliary system is mainly arranged around the engine, and the main excitation source is the engine. To improve the reliability of the power transmission auxiliary system of armored vehicles and avoid the phenomenon of running, running, dripping, and leaking, this paper mainly proposes a design method based on vibration control for the typical pipelines commonly used in armored vehicles and determines the excitation frequency of the pipelines mainly at 0~500Hz through testing the excitation source, of which the vibration energy of 150Hz~400Hz is the largest and then attenuated with the analysis of pipeline modalities by hammering test method and finite element method. By simulating the pipeline modality, and analyzing its 1st to 6th-order modes, the pipeline is optimized by changing the pipe diameter, changing the bending radius, increasing the pipeline branch, increasing the flexible link, increasing the constraint, etc., so that the pipeline avoids the resonance frequency in the corresponding mode to obtain the best design scheme of the pipeline. The research method in this paper has been successfully applied to the structural design of the test of the armored vehicle auxiliary system pipeline and other model projects. An effective design process has been formed, and the typical pipeline designed by the method has been completed with prototype trial production, bench test, and real vehicle test. The pipeline work performance is good, and the operation is smooth and reliable.
Study on imperfection sensitivity of vibration behavior in bi-directional FGMs plate
Authors: Chen Xiaochao
Published: March 2023

The sensitivity of vibration characteristics to geometric imperfection in rectangular plates made with FGMs under action of classic or elastic constraints is studied. It is assumed that the material changes in length and width directions of plate. The energy functions of plate are deduced and vibration modals are solved by means of Ritz procedure along with the modified Fourier series. The impacts of geometric imperfection, gradient material and edge conditions on vibration features of rectangular plates are simulated. Numerical results demonstrate that material gradient could be considered as control mechanism for dynamic freatures of plate. Moreover, the existence of geometric imperfections will lead singularity of vibration characteristics of plate. The imperfection sensitivity of vibration behavior in plate may provide important reference in the design or analysis of plates.
Design and Experiment of Ultrasonic Assistant Grinding Device of Spiral Bevel Gear
Authors: Han Jiaying , Mi Bowen , Li Xinrui
Published: March 2023

The precisely ground tooth surface of the spiral bevel gear still shows the thermal crack, and its micromorphology is the cause of high-frequency noise. The ultrasonic assistant grinding (RUAG) technology has the unique advantage of solving these problems. Therefore, this paper designed the split-type rotary device in which the disc grinder and amplitude horn are core components and bolted together. A deformation coefficient was proposed to calculate the strain stress of the disc grinder. Combined with the stepped horn resonant theory, the theoretical model of a multi-step rotating body can be used to calculate the frequency and amplitude of the grinder and horn. The harmonic response simulation was adopted to verify the theoretical results. The experiment proved that the device’s frequency, node, and amplitude are reasonable. The comparison results showed that the simulated frequency and amplitude were closer to the practical one. Moreover, the difference between them increased with the dimension of the device.
Research on Spherical Self-rotating Polishing Technology
Authors: Zhu Tongbo , Cai Fan
Published: March 2023

Polishing technology is widely used in the polishing process of aspheric optical elements, complex curved surface molds, and so on because of its high machining accuracy, good flexibility, and other advantages. Based on the Preston equation, this paper deduces the material removal function of spherical self-rotating polishing by applying the kinematics principle, obtains the removal function with approximate Gaussian distribution by using computer simulation method, conducts processing technology experiments through the spherical self-rotating polishing device, analyzes the influence of polishing pressure and polishing speed on the polishing removal characteristics of ceramic materials by simulation, and verifies the stability of the removal function through experiments. The results show that the removal function graph is Gaussian distribution, which is conducive to the surface shape convergence of airbag machining. The influence of process parameters on material removal rate is in good agreement with the theory and practice and has a good linear relationship. It is a controllable and deterministic processing mode.
Vibration Suppression Technology of Integrated NC Machining of Lightweight Monolithic Panel
Authors: Yang Kai , Zhao Wei , Gao Ming , Feng Changxi , Hu Xingping , Wang Peng , Li Jiaxin , Lai Xiaoming , Gao Liguo
Published: March 2023

The new generation spacecraft module is formed by spinning as a whole, and then the whole module is processed by integrated numerical control. Due to the characteristics of the large diameter and thin wall of the module, it is easy to produce vibration in the processing. In this paper, aiming at the vibration problem of integrated CNC machining cabin body, a method of using reconfigurable fixture internal support to suppress the vibration of weak rigid cabin body overall processing is proposed, and the ANSYS finite element analysis software is used to simulate and analyze the internal support force. The results show that the thickness uniformity of the bottom skin is similar, the dimensional accuracy is higher, and the effect of suppressing cutting chatter is obvious. This paper also improves the design of the milling tool with an unequal helix angle, adds DLC tool coating, and increases the tool rake angle. The simulation results of cutting force based on the FORCE module show that the cutting force is reduced by 31% and chatter in machining is suppressed compared with that before the tool is improved. Through the cycloid milling strategy, the wrap angle between the tool and the workpiece is reduced. It reduces the cutting force, reduces the cutting heat, and ensures the consistency of the product wall thickness and the roughness requirements. The experimental results show that these methods can effectively suppress the vibration in the processing and control the thickness of the integrated numerical control processing panel between 1.47-1.77 mm.
Discussion on the Range Configuration Strategy of Tension Sensor of Icing Monitoring Terminals of High-Voltage Transmission Line
Authors: Li Wenrong , Su Junyuan , Qin Haodong , Yang Yueguang , Huang Junlan
Published: March 2023

Online monitoring of transmission line icing is an important means of anti-icing in the power grid. The accuracy mainly depends on the accuracy of the terminal tension sensor, which is one of the main sources of monitoring errors from large range configuration of tension sensor. This paper analyzes the working principle and characteristics of tension sensors and the load calculation method of different types of insulator hanging points to determine the output error of over-range configuration tension sensors. It finally proposes a principle and a calculation method for tension sensors’ range configuration, which is verified to be reliable by experiments. The results can provide a basis for the selection of tension sensors for icing-monitoring terminals and reduce the error caused by temperature drift and zero drift of tension sensors.
Development of the epoxy resin phase change proppant based on the Pickering emulsification technology
Authors: Qu Zhan-Qing , Fan Jia-Cheng , Guo Tian-Kui , Chen Ming , Wang Mei-Jia
Published: March 2023

Since the conventional solid proppant has many defects, such as poor migration and its rigid structures easy to plug cracks, liquid proppant has become a key development direction. A phase change proppant is developed based on the emulsified thermosetting resin system and evaluated in this paper. On the basis of the bisphenol A type epoxy resin, the phase change proppant system adopts the adduct of diethylene triamine and butyl glycidyl ether as epoxy resin curing agent and the SiO2 particles (1% of the resin mass) as the emulsifier, and then adds the hollow glass microspheres (1.25% of the resin mass) and the absolute ethyl alcohol (25% of the resin mass) as the thinner to reduce resin density and dilute resin. Proppant particles with major sizes of 4.5mm, 3mm, 2-2.5mm, 2mm, 1mm and 0.5mm are obtained through process optimization. After evaluation, the obtained proppants are of low density and high compressive strength, and their migration capability and flow conductivity are qualified for the exploitation of unconventional reservoirs with high closure pressures.
Design of automatic operation system of trowel based on stereo vision-inertial
Authors: Shang Yanjun , Liu Zhao , Zhu Yutian , Zhao Shiwen , Yao Yuanzhou
Published: March 2023

The trowel is a construction machinery used for slurry lifting and trowelling cement concrete surfaces. The machine is noisy and has certain dangers during operation. This paper focuses on the automatic operation of the trowel and takes the driving hydraulically driven trowel as the research platform. According to the overall requirements of automatic operation, with the stereo visual-inertial navigation system as the core, a positioning system and a full coverage path planning scheme are designed. The real data was collected in the test site for the experiment, and the results show that the stereo visual-inertial navigation system can provide the required positioning accuracy for the trowel.
Study on the facility airworthiness requirements and conformity verification method of aircraft leveling meanings
Authors: Han Li
Published: March 2023

The aircraft measurement is the inspection of the relative position of the various parts, the installation quality of the parts and their deformation in the process of use, and the airworthiness regulations have clear requirements for this. This paper carries out the research based on the requirements of the airworthiness regulations, clearly determines the facility airworthiness technical requirements of the aircraft level, gives the suggested design requirements, clarifies the practical and feasible compliance verification methods, and provides a reference for the airworthiness certification of the civil transport aircraft.
Research on Automatic attitude adjustment Technology of Suspension rail of the Unfolding frame
Authors: Zhao Danni , Li Deyong , Li Haiyue , Zhao Linna , Zhang Yue , Gao Yongliang , Yang Hongmiao , Li Jinbao
Published: March 2023

Spacecraft solar wings, antennas, and other space deployment mechanisms need to be unloaded by gravity during the ground launch test. At present, the most widely used is the guide rail type Micro-gravity unfolding frame, and the rail needs to be adjusted horizontally before the test is carried out. Aiming at the shortcomings of the current rail debugging relying on labor, difficult high-altitude operation, and low debugging efficiency, a guide rail automatic attitude adjustment device is proposed, which can quickly realize the efficient adjustment and attitude maintenance of the rail level. After test verification, the system can increase the local level of the guide rail from the traditional 0.02 mm/m to 0.01 mm/m, the overall level from the original 0.1 mm/m to 0.02 mm/m, and shorten the commissioning time from the original 4 h to 1 h. The power-off holding ability is strong, which greatly improves the efficiency of the ground test. The research results have been applied to other spatial deployment institutions that conduct tests based on rails.
Research on Resistance Prediction Method of Conventional Planning Hull Based on BP Network
Authors: Gao Xianjiao , Jiao Jun , Shi Shengzhe
Published: March 2023

Resistance performance is an important factor affecting the usability and economy of planning hulls. This paper proposes to use the neural network to build the relationship model between the characteristic parameters of the planning hull and its hydro-resistance performance. Six form parameters (such as overall length, breadth of chine line, et al ) and six state parameters (such as displacement, velocity, et al.) are selected as characteristic parameters. The resistance coefficient is selected as the research indicator. The neural network response model is constructed by taking characteristic parameters as input variables and the research indicator as the output of the network. The mean squared error and determination coefficient are treated as performance function and assessment indicators respectively. After training, we compare the output of the network with the experimental results. It shows that the predicted value of the network agrees well with model test results with the determination coefficient reaching 0.99. This illustrates that the trained network has high precision in capturing the relationship between characteristic parameters and resistance coefficient, which provides a new way of resistance prediction for the conventional planning
Adsorption Structure Design of a Wall Climbing Robot for a Spherical Tank
Authors: Wang Guoqing , Meng Fanzhao , Wei Hongmei , Li Xuan , Wei Zhigang , Yin Wenbo
Published: March 2023

The main body of the LPG (Liquefied Petroleum Gas) spherical tank is a spherical shell, which is a component to store materials and bear the working pressure of materials and the static pressure of the liquid column. Because most spherical tanks are pressure or cryogenic vessels, most materials are flammable and explosive, and the loading capacity is large. Once an accident occurs, the consequences will be unimaginable. Therefore, more and more companies and research institutes are now involved in the research of robots suitable for the operation of spherical tanks. Among them, the foundation and premise of the spherical tank climbing robot are stable and have reliable adsorption capacity. Based on in-depth investigation and research on the existing robot adsorption structure and considering its actual working conditions, this paper designed an adsorption technology based on the combination of permanent magnetic adsorption and electromagnetic adsorption, which mainly focuses on permanent magnetic adsorption and automatically adjusts the electromagnetic adsorption force according to the robot attitude. Thus, the robot has good adsorption and driving performance at any position on the ball wall.
Reliability-based Graded Maintenance Cycle Optimization of Electronic Equipment
Authors: Shen B , Liu S R , Xie S , Xiu R
Published: March 2023

With the increase in the number of modern equipment and the huge scale of equipment, the role and significance of clustering and systematic research have gradually become prominent. This paper studies the relationship between the benefit of a system composed of multiple pieces of electronic equipment and the maintenance period and uses the Monte Carlo method to realize the quantitative simulation of the system’s benefit under the known maintenance period. On this basis, the simulated annealing algorithm and genetic algorithm in the intelligent optimization algorithm are used to optimize the typical two-level maintenance cycle combination, which can quickly obtain the maintenance cycle that maximizes the annual system benefit. Finally, the difference between the results of the two optimization algorithms is compared and analyzed.
Simulation study on triboelectric nanogenerator based roller of belt conveyor
Authors: Tian Han , Liu Boyan , Zhao Jian , Wang Honglei , Yang Xiaohui
Published: March 2023

In this paper, a belt conveyor roller based on triboelectric nanogenerators is designed. This device can harvest energy from the roller rotating without introducing additional resistance to system and increasing the overall energy consumption. In this paper, a simulation study is conducted for different structures of the rollers to investigate the effects of the electrode number and electrode radian on the electrical properties of the device.
Research on the Economic Dispatch of Power Systems with a High Proportion of Renewable Energy based on Improved PSO
Authors: Jin Mingming , Wang Mingdong
Published: March 2023

The penetration rate of renewable energy sources represented by wind power and photovoltaics in the power grid is increasing, adding complexity to unit dispatch. In this paper, a multi-objective optimization model is established for power systems containing wind power and photovoltaic economic dispatch. Firstly, the power generation cost of traditional units, the emission cost of traditional units, the power generation costs of wind turbines and photovoltaics, and the output characteristics of wind power and photovoltaics are analyzed. Secondly, a multi-objective economic dispatch model with the lowest power generation cost, the smallest emission cost, and the smallest power generation cost of new energy units are established, and the power flow balance constraint, supply and demand balance constraint, unit output constraint, and node voltage constraint are considered. Then the improved particle swarm algorithm is proposed to solve the multi-objective function to obtain better convergence and optimal solution. Finally, the simulation is carried out in the IEEE-30 node system and the HRP-38 system, which compares and illustrates the similarities and differences of the solution results of various algorithms under multi-objective and verifies the effectiveness of the algorithm.
Study on Carbon Ecological Evaluation Method of Multi-microgrid under Two-carbon Background
Authors: Lin Han , Wang Zhijie , Zhou Xianli
Published: March 2023

In view of the current problem that there is no comprehensive, scientific, and reasonable evaluation method for the comprehensive operation benefit of a multi-microgrid under dual-carbon background, the carbon ecological evaluation index system and evaluation method model of the multi-microgrid under dual-carbon background are put forward. First, with the relevant indicators of dual-carbon as the core, the carbon ecological evaluation index is selected on the basis of fully analyzing the influencing factors of the carbon ecology of the multi-microgrid. Then, through the correlation analysis of the index model and data, the multi-microgrid carbon ecological evaluation index system is constructed based on the network-level analysis method. And the comprehensive empowerment of the ecological carbon index is made based on the optimization combination model of subjective and objective weights. Then VIKOR evaluation method is the carbon ecological evaluation results. Finally, a multi-microgrid carbon ecological evaluation function based on deep reinforcement learning is established to ensure the accuracy and real-time performance of the evaluation results.
Polarization-Independent Dual-Band Metasurface Absorber for Wireless Power Transmission
Authors: Gao Xiang , Wang Xinren , Wang Weijun
Published: March 2023

A new design of a polarization-independent dual-band metasurface absorber based on an improved Minkowski fractal structure is proposed in this paper. It is designed for wireless power transmission. The proposed metasurface absorber is composed of many sub-wavelength elements. By adjusting the structure of the elements, it has rotational symmetry and multi-frequency resonance characteristics. The proposed metasurface absorber array can keep more than 87% harvested efficiency at 2.45GHz and 93% harvested efficiency at 5.8GHz for arbitrary polarization of incident electromagnetic waves. The working frequency of the proposed absorber can cover the main working frequency bands of the current microwave wireless energy transmission system. The proposed metasurface absorber, which has the great advantage of subwavelength, polarization-independent, and high harvested efficiency, is suitable for wireless power transmission, especially in ambient power harvesting and UAV remote power supply.
Fault diagnosis method of hot die forging press based on short-time Fourier transform and optimized convolutional neural network
Authors: Yuan Chao , Ma Xiaotao , Ling Yunhan , Zhang Nan , Lin Boyu , Pan Lidong , Hou Huimin , Zhang Hao
Published: March 2023

Aiming at the vibration signals of rolling bearings of a hot die forging press, which are nonlinear, unstable, and easily disturbed by strong background noise, a fault diagnosis method based on a short-time Fourier transform and optimized convolutional neural network was proposed. First, the Fourier transform was applied to the vibration signals of rolling bearings of a hot die forging press to obtain complete time-frequency samples. After spectrum compression, it is input into the convolutional neural network model. By optimizing activation function and adjusting network parameters, the purpose of efficient and fast detection in the case of small samples can be achieved. Through the simulation test, the feasibility and effectiveness are verified. The results show that the proposed method has high recognition accuracy for fault diagnosis of rolling bearings of hot die forging press.
Research on Welding Process of Duplex Stainless Steel S31803
Authors: Liu Jian , Niu Huli , He Yazhang , Zhang Yinuo , Sun Xinyan
Published: March 2023

The welding test of duplex stainless steel S31803 pipe was carried out by means of argon tungsten arc welding as backing, hot welding, and manual arc welding as filling and covering. The mechanical properties, microstructure, phase ratio, and corrosion resistance of the welded joint were studied and analyzed through the test method. The results show that the appropriate welding parameters can control the proportion of ferrite and austenite, the mechanical properties, ferrite content, and pitting resistance of welded joints to meet the relevant requirements of the standard, and the established welding process has a good guiding role for the welding of duplex stainless steel in gathering and transmission pipelines.
Simulation design based on piezoelectric photoelectric composite energy harvester
Authors: Wang Jieping , Song Jiaming , Li Shixiang , Liu Hongmei , Dou Yanwei
Published: March 2023

A simulation design based on piezoelectric-photoelectric composite energy harvesters is proposed to solve the limitation that different energy harvesters can only work under certain conditions. The design of composite energy harvesting can capture sunlight and produce electrical energy and can also harvest vibrational energy in the environment to generate electricity from it. Cantilever beams with 6 different structures are simulated. The resonance frequency of the T-shaped cantilever beam is only 40 Hz, which can be used to collect vibration energy in the environment. The effect of different thicknesses of perovskite solar cells on the output performance was simulated. When the perovskite layer was 500 nm thick, the open circuit voltage could reach 1.08 V. The piezoelectric module and the photoelectric module are integrated into the energy collection circuit, which can collect vibration energy and light energy at the same time. The maximum output power may be obtained as 290 μW when the load resistance is 35 KΩ, and the output voltage at this time is 3.18 V. The structure broadens the application environment of the energy harvester and has the function of improving the output.
Intelligent optimization of landing gear retraction based on physical simulation
Authors: Ye Yuxin , Yin Yin , Wei Haifeng , Wang Boliang
Published: March 2023

The design of the retraction mechanism is an important part of landing gear design, and optimizing the space retraction mechanism is extremely difficult. An intelligent optimization model of landing gear retraction based on physical simulation is established to investigate further the recently proposed innovative design method for landing gear retraction trajectory. The theoretical kinematic model is combined with a collision detection algorithm to realize the interference check during landing gear retraction. An intelligent algorithm uses the minimum clearance between the landing gear and cabin segment as the evaluation index to optimize the key retraction parameters. The results of the optimization case show that the physical simulation model based on the Devillers algorithm established in this paper can effectively guide the intelligent design of key parameters of landing gear retraction.
Simulation and Optimization for Position Servo Control System of Switched Reluctance Motor
Authors: Diao Han , Xia Hongji
Published: March 2023

Switched reluctance motors are widely used in household appliances, textile machines, electric vehicles, and other fields due to their simple structure, low cost, high reliability, high efficiency, large starting torque, and wide speed regulation range. With the continuous expansion of the application field of SRM, higher requirements are put forward for the design of the motor position servo control system. The control system should be highly accurate and easy to deploy and have strong anti-interference. Based on the traditional switched reluctance motor control method, this paper designs a feedforward control position loop and applies CVC control at low-speed conditions to optimize the accuracy, anti-interference, and torque ripple characteristics of position servo control. The simulation results prove that the design results of the servo control system are correct and effective.
Research on Heat Dissipation Characteristics of Protective Fluid for Immersed Lithium-ion Battery Module
Authors: Yu Shuai , Xu Yanzhe , Liu Fei , Wang Yongmao , Leng Feng , Hu Qiwei
Published: March 2023

In this article, the immersed lithium-ion battery module’s liquid cooling and heat dissipation scheme are studied, and the heat dissipation characteristics of the large-capacity battery module after the battery is grouped are analyzed. The simulation models of the liquid cooling system’s five inlet and outlet layouts are established. The numerical results show that immersed liquid cooling method can effectively prevent and reduce the temperature rise of large-capacity battery modules. The layout of the imports and exports can influence the heat transfer effect, which is of guiding significance for the design of immersed protective fluid heat dissipation of lithium-ion battery modules.
Research on the Aerodynamic Performance of an Airfoil
Authors: Chen Haotian , Liu Yijun , Zhang Yunuo
Published: March 2023

Airfoils provide lift force for planes and keep planes flying in the atmosphere. Different airfoils have distinct performance characteristics based on their shapes, influencing the flying condition of planes and people’s safety. Therefore, an airfoil’s shape must be carefully studied and deliberated on because it’s an engineer’s professional duty to protect people’s safety with engineering knowledge. In this paper, physical and mathematical models are applied to analyze the shape and corresponding characteristics of an airfoil. Models, including Bernoulli’s Equation and Ideal gas Law, are applied, which are fundamental engineering models. Professional computational tools, including Matlab, are also utilized for the accuracy of data and plots and convenience in data analysis. As aeronautics technology keeps developing, more challenges will arise. Based on the data of existing airfoils, this paper also brings some considerations for the future of airfoil designs which are going to need to satisfy more flying conditions and types of aircraft.
Improved CsPbBr3 Light-Emitting Diodes with Sodium Trifluoroacetate Additive
Authors: Hao Xiaoming , Si Junjie , Zhao Hong , Liu Zugang
Published: March 2023

The perovskite light emitting diodes (PeLED / PeLEDs) possess the high efficiency and the wonderful color purity properties. However, the poor operational stability has hindered its broader development and commercial application. Utilizing the all-inorganic perovskites to fabricate PeLEDs is considered useful for enhancing device stability. In contrast, the resultant perovskite crystals in the emissive film show large grain sizes and low photoluminance efficiency. In this work, the sodium trifluoroacetate additive is introduced into all inorganic perovskite films to passivate surface defects and control the growth of the CsPbBr3 crystal. This approach results in inorganic perovskites with smaller grains and uniform surface morphology, which enables improved device performance.
Monte Carlo simulation of HERD side-on transition radiation detector prototype
Authors: Dai Cong , Liu Hongbang , Xu Ming , Feng Huanbo , Xie Fei , Liu Xiwen , Huang Yongbo , Lu Xiang , Dong Yongwei , Liang Enwei
Published: March 2023

The High Energy cosmic-Radiation Detection facility (HERD)
is a calorimetry-based cosmic-ray detection mission on board China
space station. A side-on transition radiation detector (TRD) focuses
on the TeV energy range calibration of the HERD calorimeter with an
error of less than 10% by measuring the Lorentz factor γ of
high-energy cosmic-ray protons. A side-on TRD prototype was
developed for the performance study and tested by Deutsches
Elektronen-Synchrotron electron beams. In this paper, the Monte
Carlo simulation based on GEANT4 was compared with the experiment
results. All simulations were in good agreement with the test beam
results.
Gender vulnerabilities in low carbon energy transitions: a conceptual review
Authors: Sadiqa Ayesha , Sahrakorpi Tiia , Keppo Ilkka
Published: March 2023

Low carbon energy transitions are of paramount importance to achieve climate goals. These transitions are not only technical and economical, but also deeply social and gendered. In this paper, we reviewed the academic literature to understand: firstly, what gender vulnerabilities have been discussed in the literature and how they have been embedded in structural dynamics. Secondly, what socio-cultural and socio-economic drivers may lead to these gendered vulnerabilities? Based on content analysis, four key themes emerged from this literature survey: land use change, gender-neutral energy policies, access to resources, and green practices, gender, and culture. These four themes indicate that there are several enabling mechanisms arising from social and structural inequalities, indicative that vulnerabilities ought not to be considered in isolation, but in relationship with others. We also explored dimensions of vulnerability (exposure, sensitivity, adaptative capacity) based on Carley et al (2018 Nat. Energy
3 621–7) to contextualise components of vulnerability in relation to gender. The main finding suggests considering further intersectional approaches to low carbon energy transitions, emphasising acknowledging, and lessening societal inequalities.
Urban expansion and archaeological sites of Wat Chulamani, the oldest temple in Muang Phitsanulok, Thailand
Authors: Kongmuang C , Nakkotchasee N
Published: March 2023

Wat Chulamani is one of the oldest and the most important Buddhist temples located on the eastern bank of Nan River in Muang Phitsanulok, Thailand. This research aimed to study land use changes of Wat Chulamani itself and surrounding areas in three periods of time: 1997, 2007 and 2017 by using Remote Sensing and Unmanned Aerial Vehicle Survey (UAV The satellite data sets derived from LANDSAT–5 TM and LANDSAT–8 OLI systems. To classify land use, supervised classification methodology has been employed using the maximum likelihood algorithm. Land use is classified into 5 classes, which are agricultural land, forest land, urban land, water land and miscellaneous land. The Geographical Information System (GIS) was used to process satellite images and to detect changes over time. The result shows that Wat Chulamani and surrounding areas have been changed because of urban expansion which was mainly induced by Naresuan University establishment in 1990. The observed change shows a reduction of agricultural land and an increase in urban land in the past two decades. This paper demonstrates the potential and usefulness of UAV for mapping and monitoring the archaeological sites. It has been found that Wat Chulamani has experienced a number of changes and renovations.
Risk assessment of flash flood situation under land use change using daily SWAT streamflow simulation in Loei Basin, Northeastern, Thailand
Authors: Prasanchum H , Pimput Y
Published: March 2023

Flash flood typically occurs in the wet season caused by heavy rain from upstream to downstream and land use changes. This research mainly aims to apply SWAT model to assess the variation of streamflow in Loei Basin, Northeastern Thailand by comparing the daily streamflow during flash flood in the rainy season in the years 2002, 2011, and 2017. This included considering the three different time periods of land use change patterns input to SWAT to assess the impact on streamflow. The result revealed that daily SWAT streamflow simulation compared to data obtained from KH58A station in 2011 was reliable as could be seen from acceptable R2 and PBIAS. In terms of the tendency of land use change, conventional agricultural was replaced with rubber plantation, sugarcane, and urbanization. From this situation, most flood risk areas occur along the mainstream from middle to northern of basin outlet, including being a municipal community area with a high density of residents. It is expected to be a risky area affected by the flood situation. The result of this research can be used as a guideline for land use and water resource management when encountering sudden changes in hydrologic conditions in the wet season.
Study of potential for earthquake acceleration around NYIA, Kulon Progo based on the history of seismicity in Yogyakarta
Authors: Pandita H , Isnawan D , Winarti  , Pambudi S , Isjudarto A , Sukartono
Published: March 2023

The need for an international airport for the Yogyakarta area has been met with the presence of the new airport, New Yogyakarta International Airport, which is located on the coast of Kulon Progo Regency. The presence of the new airport had become a debate because of its location on Congot Beach and Glagah Beach. One of the debates is the link to vulnerability to earthquakes. This study is intended to determine the Peak Ground Acceleration (PGA) in the area around the airport to the sources of earthquakes that have occurred in the Yogyakarta and surrounding areas, so that the potential level of damage that can be determined. The research method used is to use data from the location of the nearest past earthquake and then calculate the acceleration using the PGA formula. The results of calculations with shallow earthquake sources and megathrust PGA values range from 0.05 to 0.189 gal. This value when converted to the MMI scale shows the V-VII scale.
The threatened plant species in Central Kalimantan of Indonesia and its utilization potencies
Authors: Magandhi M , Lestari R
Published: March 2023

According to the IUCN Red List of plant species in Indonesia in 2021, the amount and the status of those threatened plant species are one Extinct, three Extinct in the Wild, and 856 Critically Endangered, Endangered, and Vulnerable. The ex-situ plant conservation of the threatened plants becomes very urgent in Indonesia including in Kalimantan. The purpose of this study is to find out the species and the categories of the threatened plant species distributed in Central Kalimantan of Indonesia, as well as their potential utilization. At least 125 threatened plant species of Indonesia were distributed in Central Kalimantan. The plant family with the greatest number of threatened plant species distributed in Central Kalimantan was Dipterocarpaceae (46 spp), and Myristicaceae (12 spp). In the total of those threatened plant species, 2 spp were in the category of Extinct in the Wild (EW), 16 spp Critical Endangered (CR), 30 spp Endangered (EN), and 77 spp Vulnerable (VU). Those species had the potency to be utilized for timber, food source/fruit, medicinal, and ornamental plants. The district that possessed the most threatened plant species was Katingan (40 spp.) followed by Kotawaringin Timur (37 spp.), Murung Raya (35 spp.), and Barito Utara (29 spp).
Solar activity-climate relations during solar cycle 24
Authors: Ansor N M , Johari N I , Hamidi Z S , Shariff N N M
Published: March 2023

Solar activity refers to every single Sun’s phenomenon, such as development of sunspots, solar flares, prominences etc. As determined by the number of sunspots, solar activity varies over an 11-year period. In this study, we examined the general distribution of thermosphere climate index (TCI) with respect to sunspot number during Solar Cycle 24 to obtain the pattern of thermal condition in thermosphere over the 11 years. Sunspot number, thermosphere climate index (TCI), mean temperature of surface air, and three latitudes, all obtained from NASA and NOAA, were used for this analysis. Our study found that sunspot number and TCI are directly correlated, meaning that low sunspot numbers during SC24 rising phase caused the thermosphere to cool off with low TCI readings and high sunspot numbers during solar maximum caused the thermosphere to heat up with high TCI levels. A low TCI reading of 0.25 W was recorded during solar minimum since fewer solar events penetrated the thermosphere, particularly magnetized plasma and radiation. At peak levels, Northern Hemisphere (NH) had a temperature anomaly of 1.6°C, Tropics had a temperature anomaly of 1°C, and Southern Hemisphere (SH) had a temperature anomaly of 0.6°C. Due to the lower sunspot number recorded throughout the 11 years, SC24 also happened to have the lowest TCI among many preceding cycles. There was a major correlation between the amount of plasma ejections during a specific phase and whether the thermosphere received much or little magnetized plasma. Along with SC24, mean temperatures for surface air and three latitudes also showed a gradual increase trend.