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Reshaping force for deformed casing repairing with hydraulic rolling reshaper and its influencing factors

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Petroleum Science 2024年第4期21卷 2745-2757页

作者： Hong-Fei Li Min Luo Ting-Ting Xu Qiao-Zhen Li Cong-Jian Huang school of mechanical Science and engineering Northeast Petroleum University

Hydraulic rolling reshaper is an advanced reshaping tool to solve the problem of casing deformation,which has been widely used in recent years. When it is used for well repair operation, the reshaping force provided by ground devices is generally determined by experience. However, too large reshaping force may destroy the deformed casing, and too small reshaping force may also prolong the construction period and affect the repairing effect. In this paper, based on Hertz contact theory and elastic-plastic theory, combined with the process parameters of shaping, and considering the structural characteristics of the deformed casing and reshaper, we propose a mathematical model for calculating the reshaping force required for repairing deformed casing by hydraulic rolling reshaper. Meanwhile, the finite element model and numerical method of hydraulic rolling reshaper repairing deformed casing are established by using the finite element method, and the reliability of the mathematical model is verified by several examples. On this basis, the control variable method is used to investigate the influence of each parameter on the reshaping force, and the influence degree of each parameter is explored by orthogonal simulation test and Pearson correlation analysis. The research results not only provide an important theoretical basis for the prediction of reshaping force in on-site construction, but also provide a reference for the subsequent improvement of the shaping process.

关键词： Hydraulic rolling reshaper Reshaping force Deformed casing Casing reshaping Hertz contact theory

Assessment and Enhancement of FRC of power Systems Considering Thermal power Dynamic Conditions

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CSEE Journal of power and Energy Systems 2024年第4期10卷 1371-1383页

作者： Feng Hong Yalei Pang Weiming Ji Lu Liang Fang Fang Junhong Hao Jizhen Liu State Key Laboratory of Alternate Electric power System with Renewable Energy Sources and school of Control and Computer engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Alternate Electric power System with Renewable Energy Sources School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

Frequency stability and security have been a vital challenge as large-scale renewable energy is integrated into power *** contrast,the proportion of traditional thermal power units decreases during the decarbonization transformation process,resulting in poor frequency *** paper aims to explore the potential of frequency regulation support,dynamic assessment,and capacity promotion of thermal power plants in the transition *** the dynamic characteristics of the main steam working fluid under different working conditions,a nonlinear observer is constructed by extracting the main steam pressure and valve opening degree *** real-time frequency modulation capacity of thermal power units can provide a dynamic state for the power grid.A dynamic adaptive modification for primary frequency control(PFC)of power systems,including wind power and thermal power,is proposed and *** power dynamic allocation factor is adaptively optimized by predicting the speed droop ratio,and the frequency modulation capability of the system is improved by more than 11%under extreme ***,through the Monte Carlo simulation of unit states of the system under various working conditions,the promotion of the frequency regulation capacity with high wind power penetration(WPP)is verified.

关键词： Dynamic evaluation frequency regulation power system predictive modeling wind penetration

Review on the Fabrication of Surface Functional Structures for Enhancing Bioactivity of Titanium and Titanium Alloy Implants

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Chinese Journal of mechanical engineering 2024年第4期37卷 23-49页

作者： Heng Tang Jiaxiang Xu Bin Guo Yansong Xie Yalong Sun Yanjun Lu Yong Tang Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics engineering College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518000China school of mechanical and power engineering Zhengzhou UniversityZhengzhou 450001China

Titanium and its alloys have been widely applied in many biomedical fields because of its excellent mechanical properties,corrosion resistance and good ***,problems such as rejection,shedding and infection will occur after titanium alloy implantation due to the low biological activity of titanium alloy *** structures with specific functions,which can enhance osseointegration and antibacterial properties,are fabricated on the surface of titanium implants to improve the biological activity between the titanium implants and human *** paper presents a comprehensive review of recent developments and applications of surface functional structure in titanium and titanium alloy *** applications of surface functional structure on different titanium and titanium alloy implants are introduced,and their manufacturing technologies are summarized and ***,the fabrication of various surface functional structures used for titanium and titanium alloy implants is reviewed and analyzed in ***,the challenges affecting the development of surface functional structures applied in titanium and titanium alloy implants are outlined,and recommendations for future research are presented.

关键词： Surface functional structure Titanium implant Manufacturing technology Bioactivity

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Theoretical Modeling and Surface Roughness Prediction of Microtextured Surfaces in Ultrasonic Vibration-Assisted Milling

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Chinese Journal of mechanical engineering 2024年第2期37卷 163-183页

作者： Chenbing Ni Junjie Zhu Youqiang Wang Dejian Liu Xuezhao Wang Lida Zhu school of mechanical and Automotive engineering Qingdao University of TechnologyQingdao 266525China school of mechanical engineering and Automation Northeastern UniversityShenyang 110819China

Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions,such as reducing friction,improving wear and increasing *** prediction of micro/nano surface textures is of great significance for the design,fabrication and application of functional textured *** this paper,based on the kinematic analysis of cutter teeth,the discretization of ultrasonic machining process,transformation method of coordinate systems and the cubic spline data interpolation,an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling(UVAM).Based on the theoretical model,the effect of key process parameters(vibration directions,vibration dimensions,cutting parameters and vibration parameters)on tool trajectories and microtextured surface morphology in UVAM is ***,the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling(UEVAM)was *** to conventional numerical models,the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM,which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro *** prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM,2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface *** study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

关键词： Theoretical modeling Microtextured surface Ultrasonic vibration-assisted milling Cubic spline interpolation Surface roughness

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Thermal-hydraulic performance analysis and multi-objective optimization of a microchannel with staggered semi-elliptical ribs

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Science China Technological Sciences 2024年第10期67卷 3152-3167页

作者： CUI Pan LIU Wei LIU ZhiChun school of Energy and power engineering Huazhong University of Science and Technology

To enhance the cooling capacity of traditional microchannels for high heat flux electronic devices,a microchannel design with staggered semi-elliptical ribs is proposed in this *** numerical simulations,the flow characteristics of the designed microchannel are compared with those of a smooth one,and the effects of rib width（Wr）,rib height（Hr）,and rib length（Lr）,on the thermal-hydraulic performance are investigated under laminar flow *** results show that the periodically arranged ribs induce periodic vortices within the microchannel,effectively promoting fluid mixing and enhancing heat *** Hrhave similar effects on microchannel performance,with an increase in them leading to an enhanced thermal performance at the expense of deteriorated hydraulic ***,Lrhas a comparatively weaker influence,with both the heat transfer and flow resistance initially growing with increasing Lrand then *** strike a balance between the two performances,a multi-objective optimization on the three geometrical parameters is conducted at a Reynolds number（Re） *** with simulation data,artificial neural networks are trained as surrogate models,and a multi-objective genetic algorithm is employed to derive the Pareto *** the TOPSIS decision-making method,an optimal compromise solution is determined as Wr=0.2415 mm,Hr=0.0976 mm,and Lr=0.6486 *** testing on the optimized microchannel reveals that it exhibits high heat transfer,middle flow resistance,and excellent overall performance,with the performance evaluation criterion（PEC） falling between 1.572 and 1.723 within the Re range of 220–660.

关键词： heat transfer enhancement microchannel semi-elliptical rib numerical simulation multi-objective optimization

Dynamic recrystallization mechanism, texture evolution development and mechanical characteristics of a Mg–8.7Gd–4.18Y–0.42Zr magnesium alloy by ECAP

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Progress in Natural Science:Materials International 2024年第2期34卷 376-388页

作者： Ling Zhang Yinglong Li school of Materials Science and engineering Northeastern University school of mechanical and engineering Ningxia Institute of Science and Technology

Equal channel angle pressing is recognized for its ability to refine alloy grains and alter grain orientation, thereby achieve better mechanical performance of the magnesium alloy. This study investigates the microstructures,dynamic recrystallization mechanism, texture development, and mechanical performance of GW94K(Mg–8.7Gd–4.18Y–0.42Zr wt. %) Mg alloy following ECAP-4 passes at 400°C and 3 mm/min. Results show that when high-temperature deformation is undertaken, twin formation is suppressed while dislocation slip is facilitated, increasing dislocation density during deformation. Following ECAP deformation, the sample displayed higher fracture elongation, TYS, and UTS than the as-solutioned GW94K alloy. In particular, the GW94K alloy performed well mechanically after ECAP-4 passes, with an ultimate TYS of 231 MPa, an UTS of 290 MPa, and an elongation of 14.8 %. DDRX and shear bands induce CDRX, both of which are important in plastic deformation. as well as in modifying microstructure and grain orientation during ECAP deformation.

关键词： Dynamic recrystallization mechanism Equal channel angular pressing Magnesium alloy mechanical performance Mg-Gd-Y-Zr alloy Texture development

Nanoforming of transferred metal contacts for enhanced twodimensional field effect transistors

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Nano Research 2024年第4期17卷 3210-3216页

作者： Shuoheng Xu Zheng Huang Jie Guan Yaowu Hu The Institute of Technological Sciences Wuhan UniversityWuhan 430072China school of power and mechanical engineering Wuhan UniversityWuhan 430072China school of Physics Southeast UniversityNanjing 211189China

Two-dimensional transition metal chalcogenides(2D-TMDs)have attracted much attention because of their unique layered structure and physical properties for transistor *** transferred metal contacts on these low-dimensional materials or their homogeneous and heterogeneous multilayers have generated huge interest to avoid deposition *** this paper,we show that there are large physical gaps at both the edge contact and surface contact between the transferred electrodes and the 2D materials.A method called laser shock induced superplastic deformation(LSISD)is proposed to tackle this issue and enhance the performance of the *** enhancement mechanism was investigated by molecular dynamics(MD)simulations of the nanoforming process,atomic force microscopy(AFM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)characterizations of the interfaces,and density functional theory(DFT)*** force effect of laser shock can reduce the contact gap between metals and *** electrical performances of the transistors before and after LSISD,along with MD simulations,are used to find the optimal process *** addition,this paper applies the LSISD method to the short-channel MoS_(2)/graphene vertical transistors to show potential improvement in interface contact and electrical *** paper demonstrates the first report on using mechanical force induced by laser shock to enhance metal–semiconductor interfaces and transistor performances.

关键词： laser shock nanoforming metal-semiconductor contact electronics two-dimensional transistors

ZIF-8-functionalized polymer electrolyte with enhanced performance for high-temperature solid-state lithium metal batteries

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Rare Metals 2024年第3期43卷 984-994页

作者： Jin-Fang Zhang Yuan-Yuan Wang Xiao-Feng Li Gen-Yan Zhang Ying Li Rong Liu Sheng-Liang Hu Tuo-Ping Hu Ruth Knibbe Qing-Bing Xia school of Materials Science and engineering North University of ChinaTaiyuan030051China school of Energy and power engineering North University of ChinaTaiyuan030051China school of Chemistry and Chemical engineering North University of ChinaTaiyuan030051China school of mechanical and Mining engineering The University of QueenslandBrisbaneQLD4072Australia

Solid polymer electrolytes(SPEs)with high ionic conductivity are desirable for solid-state lithium metal batteries(SSLMBs)to achieve enhanced safety and energy *** nanofillers into a polymeric matrix to develop nanocomposite solid electrolytes(NCSEs)has become a promising method for improving the ionic conductivity of the ***,a novel ZIF-8-functionalized NCSE was prepared for high-temperature S SLMB s using an in situ radical polymerization *** is found that the ZIF-8 nanoparticles could reduce the crystallinity of polymer segments and offer a Lewis acid surface that promotes the dissociation of lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)and stabilizes the TFSI^(-) anion ***,the as-prepared NCSE exhibits an outstanding ionic conductivity of 1.63×10^(-3)S·cm^(-1),an electrochem ical stability window of 5.0 V at 80℃,and excellent interface compatibility with lithium metal anode with a stable polarization over 2000 ***,the assembled SSLMBs with LiFePO_(4)cathode show dendrite-free Li-metal surface,good rate capability,and stable cycling stability with a capacity retention of 70%over 1000 cycles at a high temperature of 80℃.This work provides valuable insights into promoting the ionic conductivity of SPEs.

关键词： Lithium metal batteries Metal-organic frameworks Solid polymer electrolytes Lithium metal anode Interfacial compatibility

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Composite Braking Control Strategy for Electromechanical-Hydraulic Vehicles

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CSEE Journal of power and Energy Systems 2024年第4期10卷 1722-1732页

作者： Zewen Meng Jichao Hong Hongxin Zhang Tiezhu Zhang Xiaoming Xu Qinghai Zhao Jian Yang College of mechanical and Electrical engineering Qingdao UniversityQingdao 260071China power Integration and Energy Storage Systems engineering Technology Center(Qingdao) Qingdao 260071China school of mechanical engineering University of Science and Technology BeijingBeijing 100083China Shunde Graduate school of University of Science and Technology Beijing Foshan 528000China

Short driving ranges and low braking energy recovery efficiencies are two recognized technical bottlenecks to be overcome in electric vehicles. In this paper, a novel electromechanical-hydraulic coupling system is proposed and integrated as a powertrain for electric vehicles, which can assist the electric vehicle to fully utilize its braking energy. The hydraulic regenerative braking force and electric regenerative braking force can provide all the braking needs using the medium and small braking intensities. Furthermore, an improved compound brake control strategy based on the braking force distribution is proposed and simulated. The results show that under the premise of ensuring braking stability, the electromechanical-hydraulic coupling driving electric vehicle can adapt to various working conditions with excellent energy-saving results. The hydraulic accumulator recovery efficiency is above 99%, and the state of charge consumption rate of the battery pack can be reduced by more than 9%. More importantly, the proposed hybrid power system can significantly improve the driving range and energy efficiency, as well as reduce the consumers' mileage anxiety in electric vehicles.

关键词： Braking control strategy electric vehicle electromechanical-hydraulic coupling energy recovery state of charge