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Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

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Science China(Technological Sciences) 2024年第6期67卷 1957-1973页

作者： gao Han SHI TingNa gao XinMai LEI YanXiao YAN Dong GUO LiYan YAN Yan College of Electrical Engineering Zhejiang UniversityHangzhou310027China Zhejiang University Advanced Electrical Equipment Innovation Center Hangzhou311107China State Key Laboratory of High-speed Maglev Transportation Technology Qingdao266100China CRRC Qingdao Sifang Co.Ltd. Qingdao266111China

The operating speed of the commercial electromagnetic suspension(EMS)maglev train has been over 430 km/h,making it the fastest means of land *** the increasing demands of people traveling,it is necessary to further improve the operating speed of maglev *** to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h),the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this ***,an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance,e.g.,the characteristics of phase current,the magnetic flux density,and the electromagnetic ***,the relationship between the harmonic components of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT)to reveal the mechanism of electromagnetic force ***,to address the issues of excessive armature current density and significant electromagnetic force ripple,the linear motor is re-designed by enlarging the stator slot area and reshaping the mover's main magnetic ***,the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric ***,the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA)based co-simulation.

关键词： ultra-high-speed maglev transportation electromagnetic suspension(EMS) linear motor electromagnetic force ripple suppression

Advances in bio-inspired electrocatalysts for clean energy future

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Nano Research 2024年第2期17卷 515-533页

作者： Jing-Wen Duan Mu Min-Rui gao Division of Nanomaterials&Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Electrocatalysis can enable efficient energy storage and conversion and thus is an effective way to achieve carbon *** unique structure and function of organisms can offer many ideas for the design of electrocatalysts,which has become one of the most promising research ***,the understanding of the mechanism of bio-inspired electrocatalysis has become clearer,which has promoted the design of bio-inspired catalysts and catalytic *** bio-inspired catalysts(enzyme-like catalysts,layered porous catalysts,superhydrophobic/superhydrophilic surfaces,and so on)have been developed to enable efficient electrocatalytic ***,we discuss the key advances in the field of bio-inspired electrocatalysts progressed in recent ***,the role of bio-inspiration in increasing the intrinsic activity and number of active sites of catalysts is ***,the structure and mechanism of layered porous catalytic systems that mimic biological transport systems are comprehensively ***,the design of three-phase interfaces from micro-nanoscale to atomic scale is highlighted,including the wettability of the electrode surface and the transport system near the *** conclude the review by identifying challenges in bio-inspired electrocatalysts and providing insights into future prospects for the exciting research field.

关键词： bio-inspired electrocatalysts active sites layered porous structure three-phase interface

Towards Data-Driving Multi-View Evaluation Framework for Scratch

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Tsinghua Science and Technology 2024年第2期29卷 517-528页

作者： Xiaolin Chai Yan Sun Yan gao Department of Computer Science Beijing University of Posts and TelecommunicationBeijing 100876China Intellectual Property Institute Shandong Polytechnic CollegeJining 272067China

As one of the most popular visual programming languages,Scratch has a lot of evaluation around *** evaluation can help programmers understand their projects *** the same time,it can also provide a reference for them to browse other projects in the online *** of the existing evaluations on Scratch are carried from three perspectives:Computational Thinking(CT)ability,visual presentation aesthetics,and code *** them,the assessment of CT and code quality is mainly carried out from the program script,while the evaluation of visual aesthetics is analyzed from the perspective of image sequences generated by project *** single-view evaluation focuses on the performance of a program in a certain aspect and is *** this paper,we propose a multi-view evaluation framework to integrate various evaluations using different *** quantitatively analyze the assessment of different views driven by *** with overall evaluations that represent human opinions,we analyze their differences and *** experiments,we determine the weights of different integration policies,the proposed multi-view evaluation method can generate evaluation results similar to human opinions.

关键词： Scratch Computational Thinking(CT) visual aesthetic static analysis integration policy machine learning

Multiscale feature learning and attention mechanism for infrared and visible image fusion

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Science China(Technological Sciences) 2024年第2期67卷 408-422页

作者： gao Li LUO DeLin WANG Song School of Aerospace Engineering Xiamen UniversityXiamen 361102China Electric Power Research Institute China Southern Power GridGuangzhou 510063China

Current fusion methods for infrared and visible images tend to extract features at a single scale,which results in insufficient detail and incomplete feature *** address these issues,we propose an infrared and visible image fusion network based on a multiscale feature learning and attention mechanism(MsAFusion).A multiscale dilation convolution framework is employed to capture image features across various scales and broaden the perceptual ***,an attention network is introduced to enhance the focus on salient targets in infrared images and detailed textures in visible *** compensate for information loss during convolution,jump connections are utilized during the image reconstruction *** fusion process utilizes a combined loss function consisting of pixel loss and gradient loss for unsupervised fusion of infrared and visible *** experiments on the dataset of electricity facilities demonstrate that our proposed method outperforms nine state-of-theart methods in terms of visual perception and four objective evaluation metrics.

关键词： infrared and visible images image fusion attention mechanism CNN feature extraction

Revealing the role of calcium ion intercalation of hydrated vanadium oxides for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第8期95卷 9-19,I0001页

作者： Tao Zhou Xuan Du Guo gao Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education School of Sensing Science and EngineeringSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Exploring suitable high-capacity V_(2)O_(5)-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn^(2+)diffusion kinetics has severely limited the feasibility of such *** this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca^(2+)or Ba^(2+)into hydrated vanadium *** the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g^(-1)discharge specific capacity at 0.1 A g^(-1).Moreover,the remarkable energy density of 370.07 Wh kg^(-1)and favorable cycling stability yard outperform BaVO,pure V_(2)O_(5),and many reported cathodes of similar ionic intercalation *** addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn^(2+)diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical performance of ***,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn^(2+)insertion/extraction and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery *** work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.

关键词： Aqueous zinc ion batteries Cathode materials Ion pre-intercalation Vanadium oxides Energy storage mechanism

Topological and superconducting properties of monolayered CoN and CoP:A first-principles comparative study

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 98-108页

作者： Jiaqing gao Zhenyu Zhang Ping Cui International Center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at Microscale(HFNL)University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum ***,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to *** two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each *** a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band ***,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced *** different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon *** central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.

关键词： topological yielding otherwise

Multistate transition and coupled solid-liquid modeling of motion process of long-runout landslide

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2694-2714页

作者： Yang gao Yueping Yin Bin Li Han Zhang Weile Wu Haoyuan gao Institute of Geomechanics Chinese Academy of Geological SciencesChina Geological SurveyBeijing100081China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesBeijing100081China China Institute of Geological Environment Monitoring China Geological SurveyBeijing100081China School of Geological Engineering and Geomatics Chang’an UniversityXi’an710054China

The recognition,repetition and prediction of the post-failure motion process of long-runout landslides are key scientific problems in the prevention and mitigation of geological *** this study,a new numerical method involving LPF3D based on a multialgorithm and multiconstitutive model was proposed to simulate long-runout landslides with high precision and *** following results were obtained:(a)The motion process of landslides showed a steric effect with mobility,including gradual disintegration and *** sliding mass can be divided into three states(dense,dilute and ultradilute)in the motion process,which can be solved by three dynamic regimes(friction,collision,and inertial);(b)Coupling simulation between the solid grain and liquid phases was achieved,focusing on drag force influences;(c)Different algorithms and constitutive models were employed in phase-state *** volume fraction is an important indicator to distinguish different state types and solid‒liquid *** flume experimental results were favorably validated against long-runout landslide case data;and(d)In this method,matched dynamic numerical modeling was developed to better capture the realistic motion process of long-runout landslides,and the advantages of continuum media and discrete media were combined to improve the computational accuracy and *** new method can reflect the realistic physical and mechanical processes in long-runout landslide motion and provide a suitable method for risk assessment and pre-failure prediction.

关键词： Long-runout landslide Multistate transition Mixed solid‒liquid flow Post-failure process Numerical simulation

Energy-efficient buffer and service rate allocation in manufacturing systems using hybrid machine learning and evolutionary algorithms

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Advances in Manufacturing 2024年第2期12卷 227-251页

作者： Si-Xiao gao Hui Liu Jun Ota Key Laboratory of Traffic Safety on Track of Ministry of Education Institute of Artificial Intelligence and Robotics(IAIR)School of Traffic and Transportation EngineeringCentral South UniversityChangsha410075People’s Republic of China Research into Artifacts Center for Engineering School of EngineeringThe University of TokyoTokyoJapan

Currently,simultaneous buffer and service rate allocation is a topic of interest in the optimization of manufacturing *** allocation problems have been solved previously to satisfy economic requirements;however,owing to the progress of green manufacturing,energy conservation and environmental protection have become increasingly ***,an energy-efficient approach is developed to maximize the throughput and minimize the energy consumption of manufacturing systems,subject to the total buffer capacity,total service rate,and predefined energy *** energy-efficient approach integrates the simulated annealing-non-dominated sorting genetic algorithm-II with the honey badger algorithm-histogram-based gradient boosting regression *** former algorithm searches for Pareto-optimal solutions of sufficient *** latter algorithm builds prediction models to rapidly calculate the throughput,energy consumption,and energy *** examples show that the proposed hybrid approach can achieve a better solution quality compared with previously reported ***,the prediction models can rapidly evaluate manufacturing systems with sufficient *** study benefits the multi-objective optimization of green manufacturing systems.

关键词： Energy-efficient allocation Multi-objective optimization Energy efficiency Energy consumption Machine learning

Particle effects on the hydrodynamics in slurry bubble column reactors:A review from multiscale mechanisms Author links open overlay panel

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Particuology 2024年第8期91卷 176-189页

作者： Min An Jingqi gao Tiankuo Wang Xiangnan Li National Supercomputing Center in Zhengzhou Zhengzhou UniversityZhengzhou450001China School of Chemical Engineering and New Energy Xiamen University MalaysiaSepangSelangor43900Malaysia School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang453007China

Particles can appear as catalyst,reactant or product in various gas-liquid-solid three-phase production *** bubble column reactors(SBCRs),as a kind of three-phase reactors,are preferred for phase contacting and ***,literature studies concerning the effects of particles on the hydrodynamics of SBCRs are manifold and inconsistent in ***,the multiscale interactions between particles,turbulent eddies and bubbles determine the reactor *** review focuses on revealing the particle effects in SBCRs from the perspective of multiscale *** hydrodynamic changes due to particle effects in literature are *** parameters,including the Stokes number,the solid-to-liquid density ratio,the ratio of particle and liquid characteristic lengths,the contact angle and the particle volume fraction are adopted to evaluate the characteristics of gas-liquid-solid *** relationships between particle influencing mechanisms and these parameters are analyzed and *** experimental results are explained by different ranges of these dimensionless ***,particle effects at the mesoscale and microscale,such as the influence on the bubble dynamics and the pivoting effect on the turbulence energy spectrum,are ***,progress in modeling the SBCRs with consideration of particles effects using the Euler method are *** review aims to improve the overall understanding of the complex hydrodynamics in the SBCRs.

关键词： Slurry bubble column reactors Particle effects Turbulence characteristics Bubble dynamics CFD