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

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

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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

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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

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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

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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

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Multistate transition and coupled solideliquid 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

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Stress tensor determination by modified hydraulic tests on pre-existing fractures:Method and stress constraints

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1637-1648页

作者： Guiyun gao Chenghu Wang Ke gao National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing100085China Beijing Engineering Research Center of Earthquake Observation Beijing100085China Key laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing100085China Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen518055China

The hydraulic testing of pre-existing fractures(HTPF)is one of the most promising in situ stress measurement methods,particularly for three-dimensional stress tensor ***,the stress tensor determination based on the HTPF method requires at least six tests or a minimum of 14-15 tests(under different conditions)for reliable *** this study,we modified the HTPF method by considering the shear stress on each pre-existing fracture,which increased the number of equations for the stress tensor determination and decreased the number of tests *** shear stresses were attributed to different fractures by random sampling;therefore,the stress tensors were obtained by searching for the optimal solution using the least squares criterion based on the Monte Carlo ***,we constrained the stress tensor based on the tensile strength criterion,compressive strength criterion,and vertical stress *** inverted stress tensors were presented and analyzed based on the tensorial nature of the stress using the Euclidean mean stress *** stress-measurement campaigns in Weifang(Shandong Province,China)and Mercantour road tunnel(France)were implemented to highlight the validity and efficiency of the modified HTPF(M-HTPF)*** results showed that the M-HTPF method can be applied for stress tensor inversion using only three to four tests on pre-existing fractures,neglecting the stress *** inversion results were confined to relatively small distribution dispersions and were significantly reliable and stable due to the shear stresses on the fractures and the stress constraints *** M-HTPF method is highly feasible and efficient for complete stress tensor determination in a single borehole.

关键词： Stress tensor Hydraulic tests on pre-existing fractures Mean stress Stress constraint Hydraulic fracturing

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New Results in Cooperative Adaptive Optimal Output Regulation

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Journal of Systems Science & Complexity 2024年第1期37卷 253-272页

作者： DONG yuchen gao Weinan JIANG Zhong-Ping State Key laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China Department of Electrical and Computer Engineering Tandon School of EngineeringNew York UniversityBrooklynNY 11201USA

This paper investigates the cooperative adaptive optimal output regulation problem of continuous-time linear multi-agent *** the multi-agent system dynamics are uncertain,solving regulator equations and the corresponding algebraic Riccati equations is challenging,especially for high-order *** this paper,a novel method is proposed to approximate the solution of regulator equations,i.e.,gradient descent *** is worth noting that this method obtains gradients through online data rather than model information.A data-driven distributed adaptive suboptimal controller is developed by adaptive dynamic programming,so that each follower can achieve asymptotic tracking and disturbance ***,the effectiveness of the proposed control method is validated by simulations.

关键词： Adaptive dynamic programming cooperative output regulation gradient descent method multi-agent systems.

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Trajectory tracking guidance of interceptor via prescribed performance integral sliding mode with neural network disturbance observer

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Defence Technology（防务技术） 2024年第2期32卷 412-429页

作者： Wenxue Chen yudong Hu Changsheng gao Ruoming An School of Astronautics Harbin Institute of TechnologyHarbin 150001China

This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost ***,the velocity control in such trajectory tracking guidance systems of missiles is *** our contribution,the velocity control channel is designed to deal with the intractable velocity problem and improve tracking *** global prescribed performance function,which guarantees the tracking error within the set range and the global convergence of the tracking guidance system,is first proposed based on the traditional ***,a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid ***,an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem.A back propagation neural network(BPNN)extended state observer(BPNNESO)is employed in the inner loop to identify *** obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors,convergence times,and overshoots.

关键词： BP network neural Integral sliding mode control(ISMC) Missile defense Prescribed performance function(PPF) State observer Tracking guidance system

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An Integrated External Archive local Disturbance Mechanism for Multi-Objective Snake Optimizer

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Chinese Journal of Electronics 2024年第4期33卷 989-996页

作者： leifu gao Zheng lIU Institute for Optimization and Decision Analytics Liaoning Technical University

It is an interesting research direction to develop new multi-objective optimization algorithms based on meta-heuristics. Both the convergence accuracy and population diversity of existing methods are not *** paper proposes an integrated external archive local disturbance mechanism for multi-objective snake optimizer(IMOSO) to overcome the above shortcomings. There are two improved strategies. The adaptive mating between subpopulations strategy introduces the special mating behavior of snakes with multiple husbands and wives into the original snake optimizer. Some positions are updated according to the dominated relationships between the newly created individuals and the original individuals. The external archive local disturbance mechanism is used to re-search partial non-inferior solutions with poor diversities. The perturbed solutions are non-dominated sorting with the generated solutions by the next iteration to update the next external archive. The main purpose of this mechanism is to make full use of the non-inferior solution information to better guide the population evolution. The comparison results of the IMOSO and 7 state-of-the-art algorithms on WFG benchmark functions show that IMOSO has better convergence and population diversity.

关键词： Accuracy Sociology Metaheuristics Diversity methods Benchmark testing Statistics Convergence

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