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Ultrathin two-dimensional medium-entropy oxide as a highly efficient and stable electrocatalyst for oxygen evolution reaction

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Nano Research 2024年第4期17卷 2555-2562页

作者： Guangyuan Yan Tianlu Wang Biwei Zhao Wenjing Gao Tong Wu Liming Ou School of mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

Medium-entropy oxides(MEOs)with broad compositional tunability and entropy-driven structural stability,are receiving booming attention as a promising candidate for oxygen evolution reaction(OER)***,ultrathin two-dimensional(2D)nanostructure offers extremely large specific surface area and is therefore considered to be an ideal catalyst ***,it remains a grant challenge to synthesize ultrathin 2D MEOs due to distinct nucleation and growth kinetics of constituent multimetallic elements in 2D anisotropic *** this work,an ultrathin 2D MEO(MnFeCoNi)O was successfully synthesized by a facile and low-temperature ionic layer epitaxy *** from multi-metal synergistic effects within ultrathin 2D nanostructure,this 2D MEO(MnFeCoNi)O revealed excellent OER electrocatalytic performance with a quite low overpotential of 117 mV at 10 mA·cm^(-2) and an impressive stability for 120 h continuous operation with only 6.9%***,the extremely high mass activity(5584.3 A·g^(-1))was three orders of magnitude higher than benchmark RuO_(2)(3.4 A·g^(-1))at the same overpotential of 117 *** work opens up a new avenue for developing highly efficient and stable electrocatalysts by creating 2D nanostructured MEOs.

关键词： medium-entropy oxide two-dimensional nanomaterials ionic layer epitaxy oxygen evolution reaction electrocatalysis

Battery pack capacity estimation for electric vehicles based on enhanced machine learning and field data

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Journal of Energy Chemistry 2024年第5期92卷 605-618页

作者： Qingguang Qi Wenxue Liu Zhongwei Deng Jinwen Li Ziyou Song Xiaosong Hu College of mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China School of mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina department of mechanical Engineering National University of SingaporeSingapore 117575Singapore

Accurate capacity estimation is of great importance for the reliable state monitoring,timely maintenance,and second-life utilization of lithium-ion *** numerous works on battery capacity estimation using laboratory datasets,most of them are applied to battery cells and lack satisfactory fidelity when extended to real-world electric vehicle(EV)battery *** challenges intensify for large-sized EV battery packs,where unpredictable operating profiles and low-quality data acquisition hinder precise capacity *** fill the gap,this study introduces a novel data-driven battery pack capacity estimation method grounded in field *** proposed approach begins by determining labeled capacity through an innovative combination of the inverse ampere-hour integral,open circuit voltage-based,and resistance-based correction ***,multiple health features are extracted from incremental capacity curves,voltage curves,equivalent circuit model parameters,and operating temperature to thoroughly characterize battery aging behavior.A feature selection procedure is performed to determine the optimal feature set based on the Pearson correlation ***,a convolutional neural network and bidirectional gated recurrent unit,enhanced by an attention mechanism,are employed to estimate the battery pack capacity in real-world EV ***,the proposed method is validated with a field dataset from two EVs,covering approximately 35,000 *** results demonstrate that the proposed method exhibits better estimation performance with an error of less than 1.1%compared to existing *** work shows great potential for accurate large-sized EV battery pack capacity estimation based on field data,which provides significant insights into reliable labeled capacity calculation,effective features extraction,and machine learning-enabled health diagnosis.

关键词： Electricvehicle Lithium-ion battery pack Capacity estimation Machine learning Field data

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： Lin Zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia School of mechanical and electronic Engineering Wuhan University of TechnologyWuhan430070China department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

A Temporal Convolutional Network Based Hybrid Model for Short-term Electricity Price Forecasting

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1119-1130页

作者： Haoran Zhang Weihao Hu Di Cao Qi Huang Zhe Chen Frede Blaabjerg School of mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengduChina department of Energy Technology Aalborg UniversityAalborgDenmark IEEE

Electricity prices have complex features,such as high frequency,multiple seasonality,and *** factors will make the prediction of electricity prices ***,accurate electricity price prediction is important for energy producers and consumers to develop bidding *** improve the accuracy of prediction by using each algorithms’advantages,this paper proposes a hybrid model that uses the Empirical Mode Decomposition(EMD),Autoregressive Integrated Moving Average(ARIMA),and Temporal Convolutional Network(TCN).EMD is used to decompose the electricity prices into low and high frequency *** frequency components are forecasted by the ARIMA model and the high frequency series are predicted by the TCN *** results using the realistic electricity price data from Pennsylvania-New Jersey-Maryland(PJM)electricity markets show that the proposed method has a higher prediction accuracy than other single methods and hybrid methods.

关键词： Autoregressive integrated moving average model electricity price forecasting empirical mode decomposition temporal convolutional network

Multimode Design and Analysis of an Integrated Leg-Arm Quadruped Robot with Deployable Characteristics

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Chinese Journal of mechanical Engineering 2024年第3期37卷 41-61页

作者： Fuqun Zhao Yifan Wu Xinhua Yang Xilun Ding Kun Xu Sheng Guo Xiaodong Jin School of mechanical Engineering and Automation Beihang UniversityBeijing 100191China School of mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of the legarm chain. When the robot performs a task, reconfigurable configuration and mode switching can be achieved using this joint. In contrast from traditional quadruped robots, this robot can stack in a designated area to optimize the occupied volume in a nonworking state. Kinematics modeling and dynamics modeling are established to evaluate the mechanical properties for multiple modes. All working modes of the robot are classified, which can be defined as deployable mode, locomotion mode and operation mode. Based on the stability margin and mechanical modeling, switching analysis and evaluation between each mode is carried out. Finally, the prototype experimental results verify the function realization and switching stability of multimode and provide a design method to integrate and perform multimode for quadruped robots with deployable characteristics.

关键词： Quadruped robot Multimode design Mode switching Locomotion Operation

Influence of Mass Ratio of Resin and Stabilizer on mechanical Properties of Mo Fiber-reinforced Granite Polymer Composite

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 912-920页

作者：张超任秀华 BA Dongzhe ZHANG Jianhua LI Jianyong GUO Mengnan GAO Yinghao WANG Guixin LI Jiayang School of mechanical and electronic Engineering Shandong Jianzhu UniversityJinan 250101China Key Laboratory of High Efficiency and Clean mechanical Manufacture Ministry of Education of ChinaSchool of Mechanical EngineeringShandong UniversityJinan 250061China

Because inferior mechanical strength of granite polymer composite(GPC)has become the main drawback limiting its application and popularization,Mo fibers were added into(GPC)to improve its mechanical *** properties of matrix materials with different mass ratio of resin and stabilizer(MRRS)were investigated *** influences of MRRS on interface bonding strength of Mo fiber-matrix,wettability and mechanical strength of GPC were discussed,respectively,and the theoretical calculation result of MRRS k was obtained,with the optimal value of k=*** k=4,tensile strength,tensile strain and fracture stress of the cured resin achieve the maximum *** for k=7,the corresponding values reach the *** the increase of MRRS k,surface free energy of the cured resin first increases and then decreases,while contact angles between Mo sample and matrix have displayed the opposite *** of resin to Mo fiber is the best at k=*** load of Mo fiber and interface bonding strength appear the maximum at k=4,followed by k=5,k=3 the third,and k=7 the *** k=4,mechanical properties of Mo fiber-reinforced GPC are optimal,which is consistent with the result of theoretical *** study is of great significance to get better component formulas of Mo fiber reinforced GPC and to improve its application in machine tools.

关键词： polymer composite fiber mechanical strength interface bonding

Electrical discharge and arc milling with automatic tracking of optimal flushing direction:A novel high-efficiency compound machining method

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Chinese Journal of Aeronautics 2024年第3期37卷 351-364页

作者： Xinlei WU Yonghong LIU Pengxin ZHANG Liang QI Dege LI Chi MA Renjie JI College of mechanical and electronic Engineering China University of Petroleum(East China)Qingdao 266580China School of mechanical and Power Engineering Nanjing Tech UniversityNanjing 211816China

The arc milling method has the advantages of high machining efficiency and low cost and is independent of the strength and hardness of machined ***,frequent electrode back-offs and the risk of workpiece burning may occur if erosion products are not removed *** this study,it was found that the flushing method of the working medium had a significant impact on the machining performance of arc *** on this,a novel highefficiency compound machining method of electrical discharge and arc milling with automatic tracking of the optimal flushing direction was *** automatic tracking optimizer for external working medium injection was designed to determine the optimal external flushing direction according to the feed *** influence of flushing methods,working mediums,and machining parameters on the machining efficiency,tool electrode wear rate,machining error,and surface integrity of titanium alloys were *** results indicated that better machining performance and environmental friendliness were achieved using the compound flushing method of outer compressed air and inner deionized ***,the automatic tracking flushing method in the opposite direction of the feed direction showed superior results compared to other *** material removal rate with the opposite direction injection could be increased up to 1.62 times that of the same direction,and the relative electrode wear rate could be reduced by 14.76%.This novel method has broad application prospects for machining parts with difficult-to-cut materials in aerospace and military industries.

关键词： Arc milling Dielectric Difficult-to-cut materials Electric discharge machining Erosion Material removal rate

A complementary binary code based phase unwrapping method

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Optoelectronics Letters 2024年第4期20卷 228-233页

作者： LI Wenjie SUN Huanghe LI Fuquan WANG Beibei WANG Haijian GAO Xinyu School of mechanical and Electrical EngineeringGuilin University of electronic Technology Guilin 541004China

Phase unwrapping is used to establish the mapping relationship between camera and projector,which is one of the key technologies in fringe projection profilometry(FPP)based three-dimensional(3D)*** complementary Gray code assisted phase unwrapping technology can get a good result on the periodic boundary,it needs more coded images to obtain a high frequency *** at this problem,a complementary binary code assisted phase unwrapping method is proposed in this *** to the periodic consistency between the wrapping phase and binary codes,the coded patterns are *** the connected domain strategy is performed to calculate the fringe orders using the positive and negative image *** avoid the mistake near the periodic boundary,complementary binary code inspired by the complementary Gray code is *** fringe order correction is also discussed for different situations in the first measured *** two binary images are needed in the proposed method,and the fringe frequency is not *** the simulation and experiment have verified the feasibility of proposed method.

关键词： method. complementary phase

Advances in Active Suspension Systems for Road Vehicles

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Engineering 2024年第2期33卷 160-177页

作者： Min Yu Simos AEvangelou Daniele Dini department of mechanical Engineering Imperial College LondonLondon SW72AZUK department of Electrical and electronic Engineering Imperial College LondonLondon SW72AZUK

Active suspension systems(ASSs)have been proposed and developed for a few decades,and have now once again become a thriving topic in both academia and industry,due to the high demand for driving comfort and safety and the compatibility of ASSs with vehicle electrification and *** review papers on ASSs mainly cover dynamics modeling and robust control;however,the gap between academic research outcomes and industrial application requirements has not yet been bridged,hindering most ASS research knowledge from being transferred to vehicle *** paper comprehensively reviews advances in ASSs for road vehicles,with a focus on hardware structures and control *** particular,state-of-the-art ASSs that have been recently adopted in production cars are discussed in detail,including the representative solutions of Mercedes active body control(ABC)and Audi predictive active suspension;novel concepts that could become alternative candidates are also introduced,including series active variable geometry suspension,and the active wheel-alignment *** with compact structure,small mass increment,low power consumption,high-frequency response,acceptable economic costs,and high reliability are more likely to be adopted by car *** terms of control strategies,the development of future ASSs aims not only to stabilize the chassis attitude and attenuate the chassis vibration,but also to enable ASSs to cooperate with other modules(e.g.,steering and braking)and sensors(e.g.,cameras)within a car,and even with high-level decision-making(e.g.,reference driving speed)in the overall transportation system-strategies that will be compatible with the rapidly developing electric and autonomous vehicles.

关键词： Active suspension Vehicle dynamics Robust control Ride comfort Chassis attitude