bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite Element Analysis of Acoustic Performance of Water-filled Helmholtz Resonator with the Effect of Elastic Cavity Walls
Authors: Su Shengli , Wu Shuyou 
Published: March 2023

Abstract
Water-filled Helmholtz resonator is a primary means to reduce the hydrodynamic noise of pump and valve in naval vessels. The predicted acoustic performance of water-filled Helmholtz resonators with the effect of elasticity of cavity walls using finite element method is compared with theoretical and experimental results in references, which demonstrated the applicability and accuracy of the finite element numerical method. And then, the effect of thickness and materials of cavity walls on resonance frequency and transmission loss of resonators is discussed, including the comparison of rigid and elastic cavity walls predictions simultaneously. The results of the discussion in this paper show that the acoustic performance of water-filled Helmholtz resonators is influenced by the elasticity of cavity walls to a great extent, which must be taken into consideration in the process of design.
Analysis of Intake Performance of Forebody and Inlet on Pre-deformation
Authors: Li Siyi , Liu Lei , Liu Shenshen , Yang Xiaofeng , Wang Ziyi , Du Yanxia 
Published: March 2023

Abstract
Under long cruise conditions, the forebody and inlet of a hypersonic vehicle were sensitive to deform under the aerodynamic thermal load, which hurt aerodynamic characteristics, intake performance, and aircraft safety. A pre-deformation method was proposed by using the numerical method of fluid-thermal-structural coupling based on the in-house software, aiming at the static deformation of a typical forebody-inlet model. Three pre-deformed models were combined by the forebody/inlet deformation and then compared the intake performance between the pre-deformed models and the ideal rigid model. The results show that the pre-deformation of the forebody can not only ensure the intake performance partly but also avoid the risk of excessive pressure on the intake wall. The pre-deformation of the inlet can reduce the flow separation near the ramp wall and reduce the pressure of intake, but it also reduces the total pressure recovery coefficient and affects intake performance negatively.
Optimize the Rectifier Structure to Improve the Accuracy of Gas Ultrasonic Flowmeter Under Low Flow Conditions
Authors: Yang Bin , Zhang Ying , Shi Limiao , Zhan Xingyu 
Published: March 2023

Abstract
With the promotion of the coal-to-gas policy, the consumption of civil natural gas in China is increasing rapidly. Improving the measurement accuracy of the flowmeter is of great significance in reducing transportation costs. Computational fluid dynamics software (FLUENT) was used for simulation, the upstream choke model of a single elbow pipe was established, and the flow field in the urban pipe network’s transition area was analyzed and optimized to improve the existing commercial flow Conditioner. The effects of the Reynolds number, the installation location of the ultrasonic gas flowmeter, and aperture depth on measurement accuracy were investigated. The results show that installing the flow Conditioner can improve the velocity distribution of the flow field in the pipeline. Optimizing the flow Conditioner can shorten the installation position of the flowmeter. The optimum thickness of the flow Conditioner is 0.25D. The research results provide important theoretical significance and application value for improving the industry’s ultrasonic gas flowmeter measurement accuracy.
Three-Dimensional Computational Fluid Dynamics Simulation of the Turbine Blades of a Micro Turbojet Engine
Authors: Zhang Haotian 
Published: March 2023

Abstract
Micro turbojet engine has been widely used in both civil and military applications and their turbine blades are the key components that determine their performance. The paper analyses the influence of adjusting rotational speed and attack angle on the pressure ratio and kinetic energy efficiency of a typical type of micro turbojet engine named KJ66 using computational fluid dynamics in three-dimensional. The objective is to analyse a basic research methodology using CFD for future micro turbojet engine research and workshops to maximize efficiency. Once the related statistic and the aerodynamic performance characteristic are obtained, the attack angle and rotational speed of the turbine blade can be set respectively according to the actual requirements to meet the needs of users. Based on the simulation results, it can be derived that the highest efficiency is 93.46% at the attack angle change of -10° and rotational speed of 110000 rpm. However, the numerical simulation of other conponents such as nozzle are not included in this paper. Therefore, the results would be more accurate and convictive if the object of research can be extended to the entire micro turbojet engine.
Research on Process and Mechanical Properties of PLA Composites in Melt Deposition Molding Based on Computer Software Analysis
Authors: Cui Haijun , Meng Fanrong , Yong Ping 
Published: March 2023

Abstract
Fused deposition polylactic acid (PLA) von berg system materials have been widely used in automotive, aerospace and other fields, and in these areas, inevitably need under static load and dynamic load, so the fused deposition PLA materials under quasi-static and dynamic loading of mechanical properties, establish its parameters such as temperature and strain rate, and constitutive model is related to material performance evaluation and optimization of fused deposition parameters and key for promoting the development of the fused deposition technology.
Co-N decorated three-dimensional graphene as an efficient electrocatalyst for boosting hydrogen evolution reaction
Authors: Lyu Xiao , Li Sicheng , Chen Hao , Zhou Xianmin , Dong Zhenwei 
Published: March 2023

Abstract
Hydrogen evolution reaction (HER) is important for hydrogen generation. Due to the scarcity and high cost of noble metal-based electrocatalysts, it is eager to develop non-precious metal electrocatalysts. In this work, atomic cobalt decorated on N-doped three-dimensional graphene (Co SA/3D-NG) electrocatalyst has been synthesized. Due to the hierarchical porous structure of three-dimensional graphene by coupling effects between Co and N, the Co SA/3D-NG electrocatalyst exhibits an enhanced HER activity. The potential is -180 mV at -10 mA cm−2 and the Tafel slope is 102.53 mV dec−1. It also presents highly electro-catalytic stability in acidic electrolytes. The work reveals a facile pathway to synthesizing efficient HER electrocatalysts.
Study on the Influence of Cu Content on Phase Transition Characteristics of Fe75Ni(25-x)Cu
x
Elastocaloric Refrigeration Alloys
Authors: Chen JiaXian , Shi YongJun , Li XianFa , JunYuAn  , Yang YaBin 
Published: March 2023

Abstract
In this study, the mechanical alloying (AM) and powder metallurgy (PM) techniques were adopted to synthesize the Fe75 Ni(25-x) Cu
x
elastocaloric refrigeration alloys to research the effect of Cu contents on phase transition characteristics and microstructure of Fe75Ni(25-x) Cux elastocaloric refrigeration alloys. The conclusion was drawn that, with increasing Cu content, the phase transition characteristics changed and presented different changing trends. It was found that the phase enthalpy change value was 43.34J/g when the Cu content was 7at%, which was about 1.26 times of Fe15Ni (wt%) alloy. In addition, the FeNiCu alloy was a single-phase alloy with a crystal space group structure of Im-3m when the Cu content was 7at%, and the FeNiCu alloy was a two-phase alloy with crystal space group structures of Im-3m and Fm-3m when the Cu content was more than 7at%. This study provided an experimental basis for the theoretical investigation of the phase transition mechanism of FeNiCu elastocaloric refrigeration alloys.
Study on the Influence of Wire Electrical Discharge Machining on Fatigue Properties of Q345B Materials
Authors: Wang Yue , Wang Cuiying 
Published: March 2023

Abstract
To study the effect of wire electrical discharge machining (WEDM) on the fatigue performance of materials, the mechanical properties of Q345B material used in the grader frame were tested by the single-surface and double-surface of WEDM in this paper. Through the comparison and analysis of the test results, it is found that the yield strength and fatigue strength of the material processed by double-surface machining are 5.2% and 4.2% higher than those processed by single-surface machining, and the tensile strength has no obvious change.
Preparation of bimetallic organic framework nanocrystals and application of its calcined composites in electrocatalytic hydrogen evolution
Authors: Dai Jianbing , Wang Junyang , Liu Zhao 
Published: March 2023

Abstract
Zeolitic imidazolate frameworks (ZIFs) have attracted extensive research interests because of their porosity, large specific area, and adjustable aperture. In particular, a series of nanomaterials derived from ZIF-67 precursor has broad application prospects in energy and environment. In this paper, Co-ZIF nanocrystal was synthesized by solvothermal method, by introducing a second kind of transition metal Ni, the NixCo1-x-ZIF nanocrystals with single metal Co-ZIF structure were synthesized. NixCo1-x-O composites were obtained by oxidation of NixCo1-x-ZIF nanocrystals, and the electrocatalytic hydrogen evolution activity of composites modified glassy carbon electrode in 1 M KOH solution was tested. It is found that the Ni0.5Co0.5-O composites have the lowest overpotential compared with similar composites.
Study on Penetration Behavior of the Reactive Material Composite Jet against Concrete
Authors: Li Hong-da , Chen Ting-hao , Liu Cheng-zhe , Duan Hui , Zhang Zhi-li 
Published: March 2023

Abstract
To improve the damage performance of the shaped charge when damaging the concrete target, a new structure of shaped charge with reactive material composite liner was proposed. The behavior of reactive material composite liner-shaped charge penetrating the concrete target was researched by numerical simulation in the finite element simulation platform Autodyn-2D. The effects of the ratio of liner diameter and the ratio of the liner thickness of the inner liner to the composite liner on the penetration depth, hole diameter, and the following behavior of reactive materials were obtained. Numerical simulations show that, with increasing the liner diameter ratio and the liner thickness ratio, the penetration depth and hole diameter of the composite jet into concrete first increase and then gradually decrease. However, the increase of the liner diameter ratio and thickness ratio also means a decrease in the reactive materials’ total mass, which will significantly affect the following reactive materials into the penetration hole. Simulated results further show that it is better to find out that the liner diameter ratio is 0.7 and the liner thickness ratio is 0.2~0.4. The penetration depth and hole diameter of the composite jet into the concrete match well with the quality of the following reactive materials.
Out-of-plane Ferromagnetic Resonance and Surface Spin Wave Modes in Ni80Fe20 Film on Ripple-Patterned Sapphire Substrate
Authors: Xu Xu , Huang Haoyang , Jin Lichuan , Wen Tianlong , Liao Yulong , Tang Xiaoli , Li Yuanxun , Zhong Zhiyong 
Published: March 2023

Abstract
The study of surface magnetic anisotropy of magnetic films is beneficial to understanding the behaviors of films at high frequencies and further promoting their high-frequency magnetic applications. We investigated the out-of-plane ferromagnetic resonance (FMR) and surface spin wave modes in 40-nm Ni80Fe20 (NiFe) films deposited on ripple-patterned sapphire substrate with periodicity and a flat sapphire substrate by broad-band FMR technique. When measuring the FMR of the film on ripple-patterned substrate, the in-plane angle (𝜑
H
of the external applied magnetic field was along the direction of the ripples (𝜑
H
= 90°) and perpendicular to the ripple direction (𝜑
H
= 0°) respectively. The spin-wave resonance spectra consisting of up to two surface spin wave (SSW) modes were observed as the external magnetic field polar angle θH
varied from “in-plane configuration” (θH
= 90° ) to “out-of-plane configuration” (θH
= 0°). As the decrease of θH
, the two surface spin excitations disappeared in sequence and further only FMR mode was observed in the region θH
which was smaller than the “critical angle” θc
. The θc
of 𝜑
H
= 90° is found to be different from that for 𝜑
H
= 0°. The dependences of field shift vs. out-of-plane angles θH
for each SSW mode were analyzed by the surface inhomogeneity model. From the model, the surface anisotropy constants Ks
of films were obtained. The results show that the values of surface anisotropy constants for the two SSW modes are different. Compared with the film sputtered on flat sapphire substrate, after introducing ripple-patterned substrate, the variation of Ks
is only on the order of 0.01 erg/cm2 for the film of this thickness.
Microstructure morphology and tensile properties of 9Cr-ODS steels added different Y2O3 contents
Authors: Xie Rui , Wang Qing , Lv Zheng , Liu Chunming 
Published: March 2023

Abstract
Oxide dispersion strengthened (ODS) steels are considered to be the promising structural material candidates for Generation IV fission reactors, fusion reactor applications, new accident-tolerant fuel (ATF) cladding materials. In this study, different contents of Y2O3 were added into 9Cr-ODS steels to realize different Y/Ti atomic ratios. The microstructure of samples, kinds, number densities and size distribution characteristic of nano-scale oxide-precipitates formed in the 9Cr-ODS steel samples were investigated by synchrotron radiation SAXS, XAFS spectrum and TEM, explained the effect of Y2O3 contents on microstructures of 9Cr-ODS steel samples. The tensile properties of the 9Cr-ODS steel samples with different Y2O3 contents were also measured simultaneously. The experimental data show when Y2O3 content is 0.3%, the density of Y-Ti-O nano-clusters is the highest, reaching to 1.39×1024 /m3. At the same time, the number density of Y-Ti-O nano-clusters is the lowest, if the Y2O3 content is 0.7%. The XAFS result of 0.7% Y2O3 sample is close to a Y2O3 reference sample. The 0.3% Y2O3 has a bigger grain size than the other two samples. The 9Cr-ODS steels with Y2O3 content of 0.3% exhibit the highest tensile strength and higher ductility properties.
Preparation and Degradation Properties of Magnesium Copper Coating based on COMSOL Simulation
Authors: Yu Xiaoming , Ma Xuexin , Wang Xiaoxi 
Published: March 2023

Abstract
COMSOL software was used to design and simulate the preparation of magnesium copper (MgCu) coating on a titanium (Ti) alloy substrate. The influence of the deposition process and other parameters on the surface quality of coating was studied. The experimental results of the simulated preparation of MgCu coating showed that the thickness of MgCu coating by vacuum evaporation plating decreased gradually from the center to the periphery, and the coating thickness mostly depended on the deposition time and was relatively least affected by the substrate temperature. At the same time, COMSOL software was used to simulate and analyze the initial degradation behavior of MgCu coating and pure Mg coating. The results of the simulated MgCu coating degradation experiment showed that the degradation rate of MgCu coating in simulated body fluid was significantly higher than that of pure Mg coating.
Research on Improvement of Clamping Device for Online Nondestructive Tensile Testing of Braided Wire Rope
Authors: Cui Weihua , Gu Weilin , Wang Hui , Liu Chunlei 
Published: March 2023

Abstract
The online nondestructive tensile testing machine can crush wire ropes, during the safety tension test of braided wire ropes. To solve this problem, this paper analyzes the reasons for crushing phenomena from the aspects of static simulation and geometric analysis of wire ropes. In terms of static simulation of the tensile process, the equivalent stress, contact pressure and contact gap cloud map of the wire rope in the clamping jaw range are obtained. It is found that both equivalent stress and contact pressure of the wire rope reach maximum values at the transition section between the adjacent peak and trough of the sinusoidal curve, while both reach minimum values at the position of the peak and trough, where the wire rope is in a non-contact state. Concerning the geometrical analysis of the clamping surface of the jaws, the results show that the normal distance between the sinusoidal curves of the movable jaw and the fixed jaw is not constant in one period, which is the smallest at the transition section between the peak and the trough. Therefore, our group determine the destruction resulted from the unreasonable curve shape of the clamping surface, further improve the jaw curve and realize the non-damaged safety tension test of wire ropes.
Effect of Tempering Temperature on the Microstructure and Mechanical Properties of 42CrMo4 Steel
Authors: Zhang Yu , Zhao Hui , Liu Pengke , Wei Menghan , Lu Yang , Liu Zhanqi 
Published: March 2023

Abstract
This paper investigated the effects of tempering temperature (200°C, 400°C, 600°C or 800°C) on microstructures, mechanical properties, and residual stress of 42CrMo4 steel. Microstructures were characterized by OM and SEM techniques. The results show that the change in tempering temperature leads to a change in austenite, resulting in a change in hardness and toughness. The specimen showed the best combination of mechanical properties under the heat treatment condition of a tempering temperature of 600°C. The hardness, yield strength, tensile strength, area shrinkage, and elongation reached 312.74HV, 759MPa, 898MPa, 60%, and 18%, respectively. The experimental results provide a reference for the selection of the heat treatment process of 42CrMo4 steel.
Study on fatigue fracture of SW400 fine-grained high-strength steel T-lap joint
Authors: Jin Ge , Chen Yujing , Song Guoshan , Fan Qiuyue , Yu Haoxuan , Xu Guocheng , Xu Desheng 
Published: March 2023

Abstract
The SW400 fine-grained high-strength steel T-lap joints were welded by submerged arc welding. The influence of welding technology on the geometrical characteristics of welds and fatigue performance of the joints were studied by radial fatigue test with different welding parameters. The numerical analysis was used to study the characteristics of the stress distribution. And the fatigue fracture morphology was analyzed by scanning electron microscope. The results show that with the increase of welding line energy, the thickness of the weld increased, and the propagation direction of the fatigue crack changed from the weld to the base metal. When the thickness was less than 4 mm, the high-stress region was in the area of the weld around the weld root, and the fatigue crack propagated to the weld. When the thickness was greater than 4.5 mm, the high-stress region of AE and AS were in the weld around the root, where the crack propagated to the weld, while in the middle of the weld high-stress region was in the area of base metal around the weld root, crack propagated to the base metal. With the increase in the thickness of the weld, the maximum mises stress decreased, and the crack propagation rate decreased. The time of crack initiation was very short, which occurred in the high-stress region of the weld root in the middle of the weld.
Effect of Cryogenic Cooling on Cutting Surface Integrity and Surface Functional Properties of 6061 Aluminum Alloy
Authors: Wang Tianzhong , Duan Pengfei , Wang Jinhui , Wang Xiangyu , Qiao Yang 
Published: March 2023

Abstract
With the increasing environmental requirements in machining techniques, cryogenic machining technology gains more and more attention recently. We have carried out cryogenic cutting tests on 6061 aluminum alloy in this study. The effects of cryogenic cooling on machined surface roughness, surface hardness and surface functional properties were studied. The experiment results show that cryogenic cutting can reduce the surface roughness, improve the surface hardness, and thus the machined surface can obtain better wear resistance and corrosion resistance.
Analysis of Corrosion Causes of Ring Connection Fittings of ±800 kV Transmission Line
Authors: Qin Haodong , Li Wenrong , Yang Yuegang , Su Junyuan , Zhou Jiayi 
Published: March 2023

Abstract
The ring-linked fitting used in an ultra-high voltage DC transmission line project has suffered serious local corrosion after only one year of operation. Based on the macroscopic inspection, chemical composition analysis, galvanized layer quality analysis, metallographic organization analysis, scanning electron microscopy analysis, and energy spectrum analysis, the physical and chemical examination of the ring coupling fixture was carried out to analyze its corrosion causes and explore the corrosion mechanism. The results show that the galvanized layer of the rusted area was damaged by wear and tear due to external factors in the process of transportation, lifting, and installation. And the electrochemical corrosion led to the serious local corrosion of the fixture within a short period of operation. It is recommended to send someone to visually check the shape of the galvanized layer of the metal before the ring-linked fixture is put on the tower and to review the thickness of the zinc layer at the end of the fixture with a handheld zinc layer thickness tester if necessary.
Research on 20CrMnTi gear steel continuous cooling transformation behavior
Authors: Cui Haitao , Li Yonghua 
Published: March 2023

Abstract
Mechanical properties are essential for gear steel, so as the microstructure. The gear steel’s continuous cooling transformation behavior has influence on both. The performance of 20CrMnTi gear steel has a lot of room for improvement, if the continuous cooling transition behavior is clear. By using the expansion method and microstructure observation, the transformation behavior of 20CrMnTi gear steel under various cooling rates has been investigated. Through these experiments, the 20CrMnTi gear steel continuous cooling transformation curves can be getted. Through this curve, the microstructure of 20CrMnTi gear steel under different conditions can be determined. The research results of 20CrMnTi gear steel are very helpful to the industrial production of gear steel.
Design of a Fault Diagnosis Method for Transmission System of Hydraulic Support Truck for Coal Mine
Authors: Lu Zhiqi 
Published: March 2023

Abstract
To improve the speed of fault diagnosis of the handling car transmission system, it is necessary to design and analyze the fault diagnosis method of the hydraulic support handling car transmission system for coal mines. Firstly, the coupling demodulation abnormal signal is obtained, and the initial fault identification is realized by using the improvement instruction. Based on this, the fault diagnosis method for the transmission system of the hydraulic support truck(FFT) high-frequency fault diagnosis model is designed, and the fault diagnosis is finally realized through database regulation. The test results show that the diagnostic response time of the designed method is only 1.05s, indicating that the designed method is faster in diagnosis during practical application and can quickly assist in the repair of the transmission system of the hydraulic bracket handling car for coal mines, which has practical application value.