bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of measured and treatment planning system out-of-field dose for a 1.5 T MR linac
Authors: Powers Marcus , Baines John
Published: September 2023

Objective. Dose due to the electron streaming effect (ESE) is a significant contribution to out-of-field dose on the Elekta Unity MR-Linac. The aim of this work is to provide a systematic comparison of calculated and measured streaming dose for this system. Approach. Beams 1.0 × 1.0 cm2 to 5.0 × 5.0 cm2, gantry 90.0°, 1000 MU, were incident on an in-house phantom. At the beam entrance and exit surfaces of the phantom, ESE was generated in the Y-direction (IEC 61217). EBT3 film, orientated within the X–Z plane and at 14.0 mm depth in a solid water block, was used to determine ESE dose 5.0 cm beyond the phantom. The experimental arrangement was simulated in the Monaco v5.4 treatment planning system (TPS), utilising a CT phantom dataset with differing relative electron densities (RED) for the surrounding air. Horizontal (X direction) and vertical (Z direction) film dose profiles were compared to the corresponding TPS profiles. Main results. For each field, the maximum ESE dose was observed at the beam exit, the magnitude of which decreases with decreasing field size. For the 5.0 × 5.0 cm2 field, the exit and entry ESE doses were 19.6% and 7.0% of the D
max dose to water, respectively. Across horizontal profiles, differences (simulated—measured) were reduced with smaller fields and lower RED. The maximum absolute profile difference was 1.7% of the D
max dose to water for optimal RED and isocentre location. In vertical profiles an offset consistent with the Lorentz force was observed relative to the X–Y isoplane. Significance. For the fields investigated, maximum absolute differences (simulated—measured) ≤ 5.2% occurred in peak regions of ESE, at the beam entrance and exit from the phantom. Generally, there is good agreement between Monaco simulated and measured ESE. Simulated out-of-field dose is sensitive to the RED assigned to air structures and unforced RED optimises out-of-field dose calculation accuracy.
Bending performance of the CORC cable with flexible interlocked stainless steel former
Authors: Shi Yangyang , Ma Tao , Dai Shaotao , Jin Huan , Qin Jinggang
Published: September 2023

The high temperature superconducting cable on round core (CORC) is a kind of cable that could be used in fusion projects. Nevertheless, conventional copper former CORC cables require a large external force to allow the cable to endure plastic deformation and be tightly wound into solenoids. In this case, the superconducting tape will be affected by concentrated stress, resulting in a risk of critical current degradation. Therefore, this paper proposes a new CORC cable with flexible interlocked stainless steel former, which can be wound into a solenoid by applying a small external force. To verify the bending performance of this interlocked former CORC cable, a double-layer and a ten-layer interlocked stainless steel former CORC cable, as well as a double-layer traditional copper former CORC cable, are fabricated. And these three CORC cables are used to wind solenoids of various radius sizes respectively. The experimental results show that the critical bending radius of the double-layer interlocked stainless steel former CORC cable is less than 20 mm, the critical bending radius of the ten-layer interlocked stainless steel former CORC cable is less than 50 mm, and the critical bending radius of the double-layer traditional copper former CORC cable is larger than 55 mm. A self-consistent finite element model for the critical current of the CORC cable solenoid is also established. And the critical current experimental results are in good agreement with the simulation results. The results of this paper verify the excellent bending performance of the interlocked former CORC cable, which provides a good option for the preparation of insert magnets for future fusion projects.
An Improved Design of Absolute-value Detector by Using Optimized Ripple Adder
Authors: Yang Jichao
Published: September 2023

Absolute-value detector (AVD) is one of the most basic bit-operating devices, which compares the magnitude of two inputs. However, the traditional 4-bit AVD is not only time-consuming but also has a high energy consumption. This paper uses a hybrid design to optimize the 4-bit AVD by introducing an improved ripple adder in the absolute value extraction part, which then can be less energy-consuming and requires fewer transistors. The paper divides the design of AVD into an absolute value extraction part and a comparator. The input (2’s complement) can be positive or negative numbers in the absolute value extraction part. By observing the most significant bit (MSB) of the input, the design can determine the sign of input and output magnitude. For the comparator, this paper uses a logic of step-by-step comparison from the most to the least significant bits. Then, this paper finds the minimum delay of the design by critical path analysis and gate sizing. The final delay is set at 1.5 times its minimum. Device voltage optimization is applied for calculating the energy consumption. Finally, with 1.5 times the minimum delay, the energy consumption is 40% less than the consumption when the delay is the minimum.
High Precision Piezoelectric Micro Droplet Control and Generation System
Authors: Zhao Lin , Li Wang-xin , Dong Wen-fei , Jia Rui-hao , Dong Chuan-he
Published: September 2023

To analyze and design an intelligent system that can achieve the generation and control of micro droplets. This article is based on the ANSYS finite element analysis and calculation software to design a fluid piezoelectric actuator with a circular oscillator, establish an overall structural model, and provide the design principle and driving structure of the piezoelectric actuator. And different control methods and driving performance were explored. We studied the simulation method of calculating the pressure at the nozzle through the variation of signal excitation amplitude and the control basis of micro droplets. Through the excitation signal, the movement of the fluid can be controlled, and the driving control effect of the fluid has been verified through simulation calculations.
The Method of High Precision Self localization of Transmission Line Bolts by Lightweight Maintenance Robot
Authors: Hu Ran , Chen Jianqiang , Wu Jiong , Liang Chengjun , Yu Jialiang
Published: September 2023

The conventional high-precision autonomous positioning method of transmission line bolts mainly focuses on image detection and positioning. Affected by the weather environment, it is difficult to take real-time images of transmission lines, which affects the accuracy of bolt positioning. Therefore, a method of high precision and autonomous positioning of transmission line bolts by the lightweight maintenance robot is designed. Extracting the contour features of the connected area of the bolt cross arm of the transmission line, and marking the connected area of the bolt, it is easier to locate the target bolt. Build a high-precision self positioning model for the transmission line bolts of the lightweight maintenance robot, compensate for the self positioning joint error of the lightweight maintenance robot, and maximize the bolt positioning accuracy. The simulation experiment verifies that the positioning method has higher accuracy and can be applied in real life.
Performance Test of Weld Zone of Rotary Friction Welding of Titanium Alloy Drill Pipe
Authors: Zhang Wandong , Huang Yi , Wu Jiang , Shi Taihe , Zhang Qiang , Zhang Zhongshi , Yu Xiaoling , Guo Shujun , Jiang Yingbin , Yang Fugui , Sun Mingjun , Cong Peitao , Yu Hairui
Published: September 2023

With the development of complex oil and gas reservoirs, it is difficult for traditional carbon steel to meet the requirements of drill pipe materials in drilling process. Titanium alloy has gradually become a new choice of drill pipe material because of its low density and good corrosion resistance. Titanium alloy has poor weldability and weld zone of titanium alloy drill string is easy to become initial defect and lead to drill pipe failure. Therefore, it is essential to evaluate the performance of titanium alloy drill pipe weld zone. In this paper, the weld zone of titanium alloy rotary friction welding is tested. Metallographic structure, hardness, tension and impact mechanical tests, fracture toughness evaluation and bending fatigue test are carried out. The test results show that the metallographic structure of weld zone changes under the influence of temperature, resulting in different mechanical properties of weld zone from that of pipe body zone. The yield strength and tensile strength in the weld zone are higher than those in the pipe zone, but the fracture toughness is lower than that in the pipe zone. The fatigue life of specimens in weld zone is more than 107 in drilling mud environment. In general, the mechanical properties of weld zone meet drilling requirements.
Effect of laser power on microstructure and mechanical properties of selective laser melted AlSi10Mg alloy
Authors: Liu Peng , Wu Maoliang , Wu Guoqiang
Published: September 2023

Selective laser melting technology has the advantages of high machining precision, complex forming structure, short processing time, and low cost. In this work, the effect of laser power on the microstructure and mechanical properties of AlSi10Mg alloy formed by SLM was studied. The density, microhardness, and elongation of SLMed AlSi10Mg alloy increased with the increase of laser power, while the tensile strength and yield strength increased first and then decreased.
Preparation of Molybdenum Disulfide Nanopowders and Their Adsorption Performance for Rhodamine B
Authors: Fang Yueyun , Qu Qian
Published: September 2023

With industrialization, industrial wastewater, especially dye wastewater, flows into water resources, causing serious water pollution problems. Therefore, it is urgent to quarantine organic dyes from wastewater and improve water resource quality. Molybdenum disulfide (MoS2) nanomaterials are widely used in water treatment fields because of their special structure and properties; a case in point is pollutant adsorption, photocatalysis, membrane separation, and antibacterial treatment. In this paper, ammonium molybdate and thiourea were used as precursors; while the relative concentration of thiourea was increased, MoS2 nanopowders were prepared by the hydrothermal method. Then the prepared MoS2 nanopowders were characterized. The adsorption performance of organic dyes was preliminarily studied with the rhodamine B dye adsorption model.
Promotion of Salinity to Protonation of Amidine-based CO2-switchable Surfactant
Authors: Ma Sihang , Wang Yuanyuan , Sun Jinlong , Yi Xiaoling , Chang Zhidong , Hou Qingfeng
Published: September 2023

Amidine-based switchable surfactants, whose surface activity is enabled by protonation, are a desirable candidate for the development of enhanced oil recovery methods. However, studies on the influence of salt components on the protonation of amidine-based surfactants are still very limited. In this study, it has been found that inorganic salts can induce the protonation of amidine-based surfactants, using N’-dodecyl-N and N-dimethyl acetamidine (C12-DMAA) as an example. The feasibility predictions of protonation of C12-DMAA in pure water and brines were attained by quantum chemical simulation. The occurrence of partial protonation is determined by Nuclear Magnetic Resonance (NMR). In the dispersion test, variation in conductivity and pH indicated that the water molecule plays the role of proton donor in the protonation process, and the protonation level is unaffected by the presence of cationic species. Overall, this research enhances the understanding of the switchable ability, as well as the efficient utilization of amidine-based surfactants in salt-containing systems.
The effect of trace rare earth on grain size and properties of copper coating
Authors: Zhang Mingyi , Gao Ping , Jia Xiaobin , Wang Wei , Sun Quanxi , Li Shuli
Published: September 2023

Copper coating was fabricated by the forging process. The quasi-static properties of the coating were simulated by low power microscope, metallographic microscope, scanning electron microscope, bench Brinell hardness, and thermal simulation tester. The effects of rare earth on the as-cast grains, recrystallized grains, mechanical properties, and dynamic properties of the copper dome were studied. The experimental results show that the as-cast grains and recrystallized grains can be refined obviously by adding rare earth, and the mechanical properties can be improved in different amplitude. The samples with rare earth addition are more sensitive to strain rate and have higher yield strength at higher strain rate.
Tensile and Fracture Properties of the Ag/W Composite Interface from First-Principle Calculation
Authors: Du Xiaoming , Wang Xue , Liu Jide
Published: September 2023

As an important electrical contact composite, the interface bonding properties of Ag/W composite directly affect its functional properties and subsequent processing properties. In this paper, the mechanical properties and the adhesion strength of Ag(111)/W(100), Ag (111)/W(110), and Ag(111)/W(111) models are investigated by means of first-principles calculations. The Stress-strain curve reveals that the Ag/W composite interface structures have good tensile mechanical properties. The charge density shows that charge transfer occurs near the interface, which is the main reason that affects the fracture performance, and it occurs mainly between the first and second layers on the Ag side. The results of adhesion work and interface energy cannot be used to indicate the interfacial tensile strength.
The study on the preparation of AlON transparent ceramic and its ballistic resistance
Authors: Liu Fafu , Mu Xiaoming , Gao Chuang , Guo Zaizai , Zhang Cong , Guo Jianbin , Cao Jianwu , Lin Guangqing
Published: September 2023

The AlON transparent ceramic was widely used as a strike-surface layer for transparent armor because of its outstanding mechanical and optical properties. With the same protection capability, the AlON transparent ceramic armor can significantly reduce surface density and thickness compared with bulletproof glass, which can effectively improve the lightweight of armed helicopters and armored vehicles. In this work, AlON transparent ceramics were fabricated by sintering AlON powder sintered at 1960°C, which was synthesized by the method of carbothermic reduction and nitridation. More than 99.8% of the relative density of the samples of AlON ceramics was kept under hot isostatic pressing for 30 hours. The maximum visible light transmission of the AlON transparent ceramic sample amounted to more than 80 %, and the flexural strength and Vickers hardness can reach up to 350 MPa and 15 GPa respectively, exhibiting excellent ballistic performance. When 53-type 7.62 mm API hit AlON transparent ceramic, there are radial and circumferential modes during its crack growth process, which can guide the structural design of the transparent ceramic armor.
Study on the organization and properties of high-strength Ti-Zr-Mo-Al alloys
Authors: Liu Yaguang , Zhang Bo , Xu Xiaochen , Chen Lei , Chu Shaochen , Zhu Minxin
Published: September 2023

This work investigated the effect of the heat treatment mechanism on the mechanical properties and microstructure of the metastable β titanium alloy (Ti-16.3Zr-13.6Mo-6Al-1.6Cu-0.6Ni). The results reveal that the α phase morphology at the grain boundary of the as-cast changes from continuous distribution to discontinuous distribution after heat treatment at 900°C/12 h. When the solution temperature is raised to 1200°C/12 h, the α phase shows spherical distribution at the grain boundary. At this moment, the yield strength reaches about 1009 MPa, and the tensile strength reaches about 1188 MPa. In addition, the elongation is about 2.3%. Then the alloys were aged at 450°C from 4 h to 8 h after solution at 1200°C/12 h. In the aging process, the plastic deformation capacity is further reduced because a point-like α phase was precipitated in the alloy. However, the compressive strength was improved. From aging treatment at 450°C/6 h, the compressive yield strength reached about 1584 MPa, and the compressive strength reached about 2034 MPa. However, the compressive plasticity strain is only 2.1%.
Preparation of Tilted Grating Structure by Nanoimprinting Material with High Refractive Index
Authors: Zhang Ying
Published: September 2023

The vigorous development of the semiconductor industry has made people’s demand for semiconductor devices increasingly high, but with the shrinking specifications of components, traditional lithography technology has been unable to adapt to the needs of pattern refinement. In optical lithography, it is difficult to produce patterns with feature dimensions of less than 7 nm. Nano-embossing lithography technology, as the next generation of lithography technology, has reached a feature size of less than 5 nm, and even according to relevant reports, the processing accuracy of the technology has reached 2 nm. In this paper, we experimentally illustrate the structural change trend of the inclined grating structure after continuous imprinting, so that the structural height will show a downward trend with the increase of the number of embossing, and the line width of the structural plane will show an upward trend. The best effect is obtained by obtaining high refractive index glue 133 repetitive imprinting two kinds of inclined grating structures. And the nature of the embossing adhesive is proportional to its refractive index, and the higher the refractive index of the embossing adhesive with better imprinting properties.
TiN Inclusions Formation in Ti-Al Deoxidized Ultra-low Carbon Steel
Authors: Yang Chengwei , Liu Yi
Published: September 2023

TiN inclusion in steel is easy to cause surface defects in ultra-low carbon steel. TiN was studied by analyzing their formation mechanisms, compositions, and morphology through SEM (scanning electron microscope) and EDS (energy-dispersive X-ray spectroscopy). Thermodynamic analysis through kinetic simulations of the different stages of RH degassing was conducted by the FactSageTM software package. TiN inclusions can distribute either randomly or in clusters with exogenous inclusions. Most of the TiN inclusions are regular cubic shapes. Some of them have a black center which is alumina inclusion. The alumina inclusions formed by reoxidation can catch TiN inclusions and combine with them because of the strong combining affinity between them. Ti is a strong nitride former in liquid steel, and TiN mostly forms during cooling or solidification. The maximum temperature is approximately 1, 430 °C. The growth of TiN inclusions can be controlled by adjusting the Ti and N contents (N< 30 ppm).
Study on stress corrosion properties of aviation aluminum alloy friction stir welded joint at the different strain rate
Authors: Wang Miao , Pei Chongxu
Published: September 2023

Aviation aluminum alloy welded structures are subjected to stresses at different strain rates in corrosive environments such as the ocean. Studying the stress corrosion properties of aviation aluminum alloy Friction Stir Welding (FSW) structures is essential. Therefore, this paper focuses on the study of 12 mm thick 7085-T7452 high-strength aviation aluminum alloy FSW joints under different strain rates of stress corrosion properties changes and the impact of welding process parameters. The main conclusions of this thesis are as follows: For the base material (BM) and the aluminum alloy FSW joints, when the strain rate increased from 10−7 s−1 to 10−5 s−1, the stress corrosion strength increased, and the stress corrosion cracking (SCC) sensitivity index ISSRT decreases. The SCC sensitivity at the same strain rate: SS-400-120 > SS-300-60 > SS-300-120 > BM. After the Slow strain rate tensile (SSRT) test, the FSW joint fracture in the air is a transgranular ductile fracture. Meanwhile, the fracture is a ductile-brittle hybrid fracture in 3.5% NaCl solution, and the number of secondary cracks along the grain boundary increased significantly, showing obvious SCC sensitivity. The BM fracture after SSRT is ductile, showing lower SCC sensitivity.
Inhibition property of gasification ash to coal spontaneous combustion
Authors: Wang Jingtao , Guo Hang , Zhang Na , Miao Long
Published: September 2023

In view of the problems of uncomprehensive utilization of solid waste resources and environmental pollution caused by the stacking of coal gasification cinder, the gel inhibition performance of coal gasification cinder was studied. A new kind of anti-fire gel material was prepared by crosslinking with gasification cinder as the base material, HPMC as the gelling agent, and Na2CO3 as the coagulant. The effect of coal to oil gasification ash gel on coal spontaneous combustion and activation energy was analyzed in essence and phenomenon through temperature-programmed experiments and determination of marker gases. Results showed that the concentration of CO gas and C2H4 gas of anthracite during the process of temperature oxidation decreased by 38.1% and 65.8%. The inhibition rate after gel treatment was 56.4%, and the activation energy was 6.5%. It shows that the adjunction of ash gel can validly mitigate the reaction rate of the coal spontaneous combustion process and inhibit the reaction procedure between coal and oxygen. The inhibition performance is better than the common CaCl2.
Microstructure and Compressive Properties of Cellular Ti-Mo-based Alloys for Hard Tissue Prostheses
Authors: Li Yonghua , Li Junhui , Yin Bowen , Zhang Xiaoxiao , Li Yanjuan
Published: September 2023

Demands for substituting or repairing hard tissues are surging with the increase in aging populations around the world. This paper introduces the preparation, the microstructure, Young’s moduli, as well as the compression strength of cellular Ti-Mo-based alloys (TMBA) for hard tissue prostheses with biocompatible alloying elements. The cellular architecture as well as compressive properties of TMBAs meet the basic cellular and mechanical property requirements of cellular prostheses.
Optimization Design of Lubrication Performance of Planetary Gear Transmission
Authors: Wu Jianjun , Zhu Xingye
Published: September 2023

Due to the need to clarify the interaction between tooth surface lubrication characteristics and dynamic behavior, it is necessary to consider the influence of time-varying characteristics of lubrication contact on dynamic behavior and the effect of dynamic gear tooth force on lubrication characteristics, establish a friction dynamics coupling analysis model for spur gears, and achieve accurate prediction of dynamic response and lubrication characteristics. In this paper, the planetary gear transmission system model is built, the planetary gear transmission system model is solved, and the lubrication performance of planetary gear transmission is analyzed.
Design of an online customization platform for nearsighted spectacles based on additive manufacturing
Authors: Wang Xubao , Zhao Chuangjia
Published: September 2023

Currently, there are many issues with customizing nearsighted spectacles. Most designs are based on a universal standard of 25 degrees, and the frames are difficult to customize to fit the wearer’s face. This paper introduces a method for utilizing 3D printing to manufacture entire spectacles, known as additive manufacturing (AM), for parametric customization. Firstly, a user-friendly human-machine parameter platform is obtained through secondary development in SolidWorks using Python. The customization parameters of spectacles can be easily implemented on this platform. Spectacles’ parametric customization mainly includes feature scanning, parametric platform modeling, and spectacles manufacturing. In addition, after designing the model, it is manufactured through 3D printing. After passing the spectacles’ quality testing, their appearance, size accuracy, and light transmittance all meet the required standards. Additionally, at initial velocities of 10m/s and 20m/s, the maximum allowable stress of the glasses meets the following requirements: σ≤103MPa, and the deformation also meets Δl≤0.5mm. The parametrically customized spectacles designed in this study meet the quality standards.
Tribo-thermal simulation study of AMT dry clutch assembly under the continuous sliding grinding condition
Authors: He Haojie , Liu Zhaoquan
Published: September 2023

Electronic Mechanical Transmission (AMT) is an automatic transmission device that combines hydraulic automatic transmission (AT) with manual transmission (MT). AMT has the advantages of automatic transmission as well as high efficiency, low cost, simple structure, and easy manufacture in the traditional manual transmission system. In dry clutch engagement, the wear of the engagement surface should be minimized to achieve good performance. It is necessary to control some influencing factors during its use. When the car starts, the flywheel and driven disc in the clutch change from a separation state to a full engagement state. When joining, due to the increase in speed of the driven disc, relative sliding occurs between the drive and driven parts, which causes the temperature of the friction surface to rise. If the temperature is too high, the wear of friction plates will be increased, which will reduce the service life and working stability of the clutch. In this study, the coupling field transient analysis of the clutch under continuous sliding wear conditions is carried out, and the clutch temperature change and heat generated by friction are obtained by simulation calculation under the use of simulated clutch holding for 1s. Based on the results of the simulation, the factors that may affect the friction heat generation of the clutch are analyzed.
Design of Rotating and Striking Separator for Mulberry Stems and Leaves
Authors: Liang Kunyong , Wang Bo , Li Riquan , Yang Dingyong , Liang Guanghua , He Zhenfang
Published: September 2023

At present, mulberry leaf harvesting is still dominated by manual field picking, and the labor intensity of workers is high. In order to reduce the labor intensity of workers, a kind of stem and leaf separator suitable for mulberry sticks was designed by referring to the existing stem and leaf separators. The power control system, transmission system, and separation mechanism of the rotary blow mulberry stem and leaf separator are mainly designed. Through SolidWorks, the three-dimensional model of the rotary blow mulberry stem and leaf separator was established, and the finite element analysis of the conveying roller and the separating roller was carried out. The stress, strain, and deformation cloud diagram and the safety factor distribution diagram were obtained, and the design met the work requirements. The ANSYS software was used to conduct the modal analysis of the separation roll with separation elements installed. According to the first six order vibration mode diagrams, the minimum natural frequency and critical speed of the separation roll are 262.97 Hz and 155782 r/min, and the dynamic performance and structural design meet the working requirements.
Design of a dual-channel narrow band filter based on metasurface
Authors: Liu Shuhui , Liu Kaipeng , Luo Guoyu , Kong Weijie , Liu Ling , Pu Mingbo , Ma Xiaoliang , Li Xiong , Wang Changtao , Luo Xiangang
Published: September 2023

We proposed a dual-channel narrow band filter consisting of top and bottom-distributed Bragg reflectors (DBRs) and a dielectric interlayer inserted with a metasurface. Through the design of the metasurface, the two channels of the filter are guaranteed to exhibit high-quality factors with transmittance beyond 90% and full width at half maximum (FWHM) less than 10 nm. We demonstrate that the central wavelengths of each dual-channel filter can be controlled with a total of 50 nm shifts by only changing the width of the metasurface. Compared with the traditional dual-channel filter, our design is easier to fabricate and more convenient to tune the central wavelength, which is promising for ultracompact optical devices.
Research on wear law of friction plate of AMT dry clutch under continuous slip wear condition
Authors: Gao Yang , Du Haozhao , Liao Kuai , Gong Yubing
Published: September 2023

In the process of operation, because the AMT dry clutch in the process of separation and combination of the slip wear stage, this stage will cause the clutch friction plate wear, resulting in the change of the clutch power transmission performance, but also lead to the change of the clutch engagement characteristics and affect the clutch control performance. Therefore, the purpose of this paper is to study the wear law of the friction plate of the AMT dry clutch, and it is of great significance to evaluate the change in clutch transmission performance and realize the precise control of the clutch. In this paper, the ANSYS analysis software system is used to build a finite element analysis model about the wear of the friction plate of the AMT dry clutch, and a simulation of the sliding wear condition. At the same time, the method of loading heat flux is used to simulate the temperature of the sliding wear condition. The thermal deformation caused by temperature is taken as the main influence factor. To carry on the wear simulation analysis of the clutch-driven disc friction plate. Finally, the wear law of the friction plate of the AMT dry clutch is obtained.
Design and Thermal Performance of Ultra-Thin Flat Plate Heat Pipes with Composite Wick for Electronic Cooling
Authors: Xu Pengfei , Xiang Liyin , Tang Wenhui , Chen Hao
Published: September 2023

The rapidly increasing heat load and high-density packaging of electronic devices demand heat dissipation devices that possess miniaturization and high thermal performance. A series of ultra-thin flat plate heat pipes (UPHPs) with thicknesses of 1.2 mm was prepared to satisfy this demand. Strengthening rib optimization and capillary optimization were processed to restrict the entrainment limit and capillary limit of the UPHPs. Furthermore, surface modification technology with composite nanostructure coated was introduced to improve the surface wettability of capillary wick. Finally, the heat transfer capacity of the UPHPs was experimentally tested. The influence of capillary structure and liquid filling ratio on the heat transfer characteristic was investigated in detail. This work provides insight into the design and application of UPHPs for the new generation of electronic devices.
Study on temperature field and deformation field of AMT dry clutch assembly under continuous slip grinding
Authors: Liao Kuai , Ye Jiale , Gong Yubing , He Haojie , Gao Yang , Bi Yichao
Published: September 2023

In this paper, Ansys finite element analysis was used to study the temperature and deformation fields of clutches after continuous slip grinding for the 30s, 45s, and 60s, under different constraints on the pressure plate, and after cooling to room temperature. Its sliding time is extended while cooling the clutch from the highest temperature to the initial temperature through a certain setting, and then its temperature field and deformation field are analyzed at different sliding times after cooling. Through this study, we can explore the performance of this clutch under extremely harsh working conditions, to analyze whether it meets the standard of use of the corresponding car or makes corresponding optimization improvements.

As the sliding time increases, the maximum temperature of the clutch rises, and the temperature is transmitted to the inner and outer diameters centered on the sliding surface. As the temperature generated by continuous sliding grinding continues to rise, the deformation of the clutch assembly also increases, and when the temperature drops, the clutch will quickly reduce a certain amount of deformation in a short period and then gradually return to its original shape. The higher the temperature, the more likely the clutch is to deform. When the temperature is at a lower value, its ability to deform and its rebound performance will also decrease.
Fabrication of Self-Rolled Fluorinated Graphene Nanosheets and Cathode Application
Authors: Zhong Sheng , Zhao Sanyin , Wan Weihong , Cheng Jinsheng , Li Jing , Wang Haoceng , Huang Jianguo , Deng Shaoting , Bao Jianguo
Published: September 2023

A simple approach of self-rolled fluorinated graphene nanosheets (srFGN) was reported in this work. Notably, the preparation of the specific srFGN showed interesting solvent-sensitive characteristics. The research findings revealed that when an aprotic solvent was used, e.g., dimethyl sulfoxide (DMSO), the interesting srFGN was obtained readily, which was characterized by different technologies. Cathode application for primary lithium-ion batteries (LIBs) of the prepared srFGN nanoscrolls was also studied in this work, which exhibited elevated energy density (e.g., 2287.9 Wh·kg−1), excellent discharge specific capacity and reliable discharge platform, indicating it a cheap and hyperdensity cathode material for primary LIBs.
Study on the Resource Utilization of Desulfurization Slurry Concentrate in Coal-fired Power Plants
Authors: Zhang Yecai , Xiang Kelin , Liang Chao , Zu Kunyong , Zhou Yu , Liu Gang , Zhao Jun , Han Yi , Zhu Yonghou
Published: September 2023

In order to further solve the potential problem of zero discharge of existing desulfurization wastewater and improve the environmental and economic benefits of zero discharge technology, research on the resource utilization of desulfurization slurry concentrate was carried out. The basic magnesium chloride whisker prepared with it as raw material is a new composite material with broad application prospects and high economic value. The purified MgCl2 can be obtained by repeatedly eluting and purifying the concentrated solution of desulfurization slurry. Using it as raw material, we add 10mL of 2mol/L NaOH solution and 2mL of 1mol/L ammonia water into it, control the concentration of MgCl2 to 4 mol/L and the molar ratio of MgCl2 to ammonia water is 4:1, the temperature to 80 °C, and the aging time to 72 hours, and prepare a relatively ideal basic magnesium chloride whisker. This method can be used as a method for the resource utilization of the concentrated solution of desulfurization slurry.
Study on Dynamic Characteristics of the Typical Components of Ceramic Matrix Composites
Authors: Zhang Li , Guo Dingwen , Hou Feng , Zou Xuefeng
Published: September 2023

In this paper, the typical components of ceramic matrix composites are taken as the research object, the modal test and vibration test are carried out, and the frequency and strain response of the typical components of ceramic matrix composites under random vibration load is understood. The connection strength test is carried out after the typical components of ceramic matrix composites have completed the vibration test. The influence of the vibration environment on the connection strength of typical components of ceramic matrix composites was studied.
Preparation and characterization of polyvinylidene fluoride/graphene composite membranes via the electrostatic spinning method
Authors: Ni Haitao , He Jinfeng , Yang Heshan
Published: September 2023

The polyvinylidene fluoride/graphene composite membranes were prepared by electrostatic spinning under different conditions. Statistical analysis was conducted on the film-forming properties and liquid absorption rate. Scanning electron imaging technology observed the typical morphologies of the prepared membranes. The influences of process conditions, such as the graphene content, the applied voltage, the needle-collector distance, and the spinning flow rate on the typical morphology of the composites, were compared. It was found that the applied and the needle-collector distance significantly affected the thin film’s film-forming properties. In contrast, the flow rate had a smaller effect on the film properties and morphology. Comprehensive comparison results suggested that the morphology and uniformity of the fibers in the prepared composite material were relatively better at the needle-collector distance of 13 cm with a graphene content of 0.5%, the applied voltage of 18 KV, and the spinning flow rate of 0.12 μL/min.
Failure Analysis of Cracking on the Outer Pipe of 12Cr1MoV Water Wall in Thermal Power Plants
Authors: Yang Chao , Wang Yunan , Xu Yun , Zhang Xianwu , Li Hongqiang
Published: September 2023

In order to identify the main causes of cracking and leakage of 12Cr1MoV water wall tubes outside the furnace in thermal power plants, this paper uses macroscopic morphology observation, stereomicroscope observation, alloy composition analysis, Brinell hardness test, metallographic structure inspection, and other means to detect and analyze the failed water wall tube. The alloy composition content of the water wall tubes submitted for inspection is within the standard requirements, and the Brinell hardness value of the water wall tubes also meets the requirements of relevant standards, The matrix metallographic structure of the water wall tube is normal. The initial leakage point is the cracking of the fillet weld at the end of the water wall tube fin, while other leakage points are caused by the blowing of the medium leaked from the initial leakage point. The initial leakage point is formed by the fatigue crack initiated at the fillet weld of the fin end and the corrosion crack on the inner wall extending towards each other. It is recommended to further inspect whether there is still cracking at the end of adjacent water wall tube fins to prevent similar cracking from happening again. Due to the frequent changes in the “peak shaving” period and amplitude in recent years, it is necessary to design the peak shaving period or amplitude reasonably to ensure the safe operation of the boiler.
Dispatching Rules-based Optimization of the No-wait Flow Shop Scheduling Problem
Authors: Wu Weiyuan
Published: September 2023

To improve the productivity of the flow shop, this paper proposes a new mathematical model to describe the scheduling problem of the no-wait flow shop (NWFS) with the minimization makespan as the scheduling objective. In addition, a new dispatching rule PCA-AS is created using the principal component analysis (PCA) algorithm, and PCA-AS is applied to the process of solving the scheduling problem to gain a scheduling strategy with excellent performance. Finally, the paper numerically verifies that PCA-AS outperforms the shortest processing time (SPT) dispatching rule and the first-in-first-out (FIFO) dispatching rule in minimizing the makespan.
A Flexibility Analysis of Single-shear CFRP-metal Hybrid Joints under Static Tensile Testing
Authors: Huang Fu , Wang Tong , Lin Yuxiang , Zhang Xiaojing
Published: September 2023

In this paper, three static tests were carried out on Carbon Fiber Reinforced Polymer material (CFRP)-metal joints with single bolted connections. The effects of fastener diameter, fastener material, fastener clamping force, fixture, and fatigue on the flexibility of the joint were investigated. The reasonableness of secant and tangential flexibility was compared and discussed based on the load-displacement curve of the joints. The test results indicated that the fixture reduced the out-of-plane buckling of the structure and increased the flexibility of the joint. The joint became stiffer after the fatigue cycles. At the same time, the flexibility was strongly affected by the fastener diameter and materials. The clamping force had a slight effect on the flexibility.
Analysis of Driver Departure and Damage in Frontal 100% Overlap Rigid Barrier Crash Conditions with AEB Intervention.
Authors: Guo Taorong , Gong Chao , Wang Jin , Hu Jun , Xiong Jun , Liu Pengju , Ren Hongze , Ma Zhixiong
Published: September 2023

A braking robot and an in-vehicle HD camera were used to study the influence of emergency braking systems on the passive safety of vehicles, to conduct real vehicle tests on volunteers. The dynamic responses of 18 groups of volunteers under different braking deceleration speeds and different test speeds were collected, and the change rule of the driver’s forward tilt displacement during AEB braking was analyzed. The x-direction displacement of the head and shoulder of the volunteers increased with the increase of the braking deceleration speed, and there was no obvious correlation with the initial speed. Madymo was used to build a restraint system model, verified against the real vehicle crash test data. The maximum off-position state of the volunteer’s real car test was input into the restraint system model. The injury of drivers in frontal 100% overlap rigid barrier crash conditions with or without AEB effect was analyzed through simulation and comparison. It was concluded that AEB interventions do not increase the damage value with the existing passive safety development strategy.
The fracture reason of high-pressure outer cylinder bolt
Authors: Lyu Lei , Wang Yingjun
Published: September 2023

The power plant experienced a cylinder bolt fracture accident during the power generation process of the unit. This study conducted fracture research and analysis on fractured bolts through a series of macroscopic and microscopic detection methods. The analysis results indicated that the cause of the bolt fracture accident of the high-pressure outer cylinder of the 5th steam turbine this time was the improper heat treatment process during the bolt material processing stage, which resulted in coarse grain size and severe insufficient impact toughness of the bolt material. Finally, the crack occurred at the position with the largest load and gradually expanded in a brittle manner until the overall fracture failure.
Analysis of cracking characteristics and mechanism of high-strength steel after chemical oxidation
Authors: Wu Liqun , Lu Yang , Zhu Lizhi
Published: September 2023

The tooth surface of the 20CrNi2Mo worm underwent cracking after chemical oxidation. The appearance inspection results showed that there were multiple cracks on the tooth surface of the worm slice, and the direction of the cracks was perpendicular to the machining pattern. There were many microcracks on both sides of the main crack. The profile morphology shows that the crack depth reaches 1100 μm. The crack extends perpendicular to the tooth surface to a certain depth and then propagates in two transverse directions. After opening the crack on the tooth surface, observation shows that the overall section is black, and the artificially opened area is silver-white. At the interface between the artificially opened area and the initial fracture surface, the fracture surface changes from intergranular morphology to ductile dimple morphology. The energy spectrum shows that the oxygen content in the intergranular cracking area is much higher than that in the ductile dimple area, indicating that the worm has undergone intergranular corrosion cracking. After the worm tooth surface is ground, there will be certain tensile stress on the surface. During the chemical oxidation process, the worm will be exposed to many corrosive media such as OH−, and NO2
−. Under the combined action of tensile stress and corrosive ions, the tooth surface will undergo stress corrosion cracking. To effectively avoid cracking on the worm gear surface, three measures have been proposed to reduce the risk of cracking: (1) improving machining parameters to reduce grinding feed, (2) increasing destressing before chemical oxidation to reduce residual tensile stress, (3) improving chemical oxidation process to reduce solution concentration, treatment time, and treatment temperature.
The structure and hydrophilicity of MWCNT-COOH /TiO2 modified PVDF membrane
Authors: Yang Hui , Wang Jianhua , Zhang Jiaqi
Published: September 2023

MWCNT-COOH/TiO2 modified PVDF ultrafiltration membrane was created using a blended modification process with carboxyl carbon nanotubes (MWCNT-COOH) and TiO2 nanoparticles as modification additives in order to further enhance the hydrophilicity of the PVDF membrane surface. Using the techniques of scanning electron microscopy, Fourier transform infrared spectrum, and a water angle of engagement analyzer, the membrane’s structure and hydrophilicity were identified. Investigations were conducted into the effects of various MWCNT-COOH dosages on membrane structure and hydrophilicity. The results of the investigation indicated that 0.03 g of MWCNT-COOH in the casting solution was the ideal dose. The manufactured MWCNT-COOH/TiO2 modified PVDF ultrafiltration membrane had the best hydrophilicity.
Fusion of Multi-scale Features Seal End Face Fluid Characterization
Authors: Fan Zhichao , Ahmat Mutellip , Zhang Tingkun
Published: September 2023

The composite weaving of dynamic and static ring friction end faces with multi-scale features can improve the sealing performance of mechanical seals, but there is no clear mechanism of weaving action, and it is difficult to optimize seal surface weaving. In this study, a mathematical model is developed to analyze the fluid sealing performance of the composite textured mechanical seal end face with a combination of a 5-sided micro-pit and T-slot according to the mass conservation cavitation boundary condition. The change in sealing performance between the composite texture and single texture in terms of opening force and leakage volume was investigated. Numerical analysis shows that compared with a single texture, the multi-scale texture end face creates a coupling effect between the micro-pit and T-slot, which has a stronger dynamic pressure lubrication effect and improves the sealing performance of the sealing sub-seal with increased pressure. The research results can be applied to the design optimization of mechanical seal surface textures.
ZSM-5 Templated Porous Carbon: Synthesis and Characterization
Authors: Qu Huiqi , Li Bin , Lv Zhiguo
Published: September 2023

Microporous zeolite ZSM-5 is prepared by the hydrothermal method, and its structure is tuned by changing the hydrothermal conditions. Then zeolite particles with uniform size and dispersion are etched into the hollow porous structures with an alkali solution to form zeolite templates. Porous carbon materials with ordered pore channels are acquired by the carbon deposition method (CVD). The detailed steps include introducing suitable carbon sources into the pore channels of the as-prepared zeolite templates, followed by carbon vapor deposition and continuous optimization of the deposition conditions, and finally, removing the template. The hollow porous structure of the carbon material facilitates the exposure of catalytic active sites and the improvement of diffusion kinetics. The hollow porous carbon (HPC) formed by carbon deposition perfectly inherits the structure and pore attributes of the hollow hierarchical zeolite ZSM-5. It can be further used as a carbon-based catalyst support.
The Influence Factors of Incremental Forming Geometric Accuracy based on the Weighted Gray Correlation Analysis Method
Authors: Xu Hu , Sun Li Zhong , Gu Peng , Wang Bai Chao
Published: September 2023

In view of the process complexity of the pillow effect phenomenon, the orthogonal experiment was designed, and the numerical simulation of the single-point incremental forming process under various process parameters was carried out by using the finite element software. Taking the height of the specific position (i.e., bulging) of the pillow effect phenomenon as the evaluation index, the data were analyzed based on the weighted gray correlation analysis method. The influence of the forming height, sheet thickness, forming angle, layer feed, tool head diameter, and part size process parameters on the forming geometric accuracy was studied. The optimal process parameters of single-point incremental forming and the primary and secondary order of the influence on the evaluation index were obtained. The results show that the weighted gray correlation analysis can effectively reduce the geometric error of the pillow effect phenomenon form of the target part and improve the forming accuracy.