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Energy-Efficient Driving Strategy for High-Speed Trains with Considering the Checkpoints

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Chinese Journal of Electronics 2024年第3期33卷 847-858页

作者： Zixuan ZHANG Yuan CAO shuai su State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University School of Electronic and Information Engineering Beijing Jiaotong University National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University

With rising energy prices and concerns about environmental issues,energy-efficient driving strategies(EEDS) for high-speed trains have received a substantial amount of *** particular,energy-saving schemes play a huge role in reducing the energy and operating costs of *** article studies the EEDS of high-speed trains at a given time.A well-posed model is formulated,in which the constraints of the checkpoints,in addition to the speed limits,vehicle dynamics,and discrete control throttle,are first *** a given control sequence,the Karush-Kuhn-Tucker(KKT) conditions are used to obtain the necessary conditions for an *** to several key equations of the necessary conditions,the checkpoint constraints are *** case studies are conducted based on the data of the Beijing-Shanghai high-speed line to illustrate the effectiveness of the proposed approach.

关键词： Energy consumption Costs Simulation Mathematical models Energy efficiency Vehicle dynamics Optimization

Strain Gradient Finite Element Formulation of Flexoelectricity in Ferroelectric Material Based on Phase-Field Method

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Acta Mechanica Solida Sinica 2024年第4期37卷 570-579页

作者： shuai Wang Hengchang su Min Yi Li-Hua Shao National Key Laboratory of Strength and Structural Integrity Institute of Solid MechanicsSchool of Aeronautic Science and EngineeringBeihang UniversityBeijing100191People’s Republic of China State Key Laboratory of Mechanics and Control for Aerospace Structures and Institute for Frontier Science and Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China

Flexoelectricity is a two-way coupling effect between the strain gradient and electric field that exists in all dielectrics,regardless of point group ***,the high-order derivatives of displacements involved in the strain gradient pose challenges in solving electromechanical coupling problems incorporating the flexoelectric *** this study,we formulate a phase-field model for ferroelectric materials considering the flexoelectric effect.A four-node quadrilateral element with 20 degrees of freedom is constructed without introducing high-order shape *** microstructure evolution of domains is described by an independent order parameter,namely the spontaneous polarization governed by the time-dependent Ginzburg–Landau *** model is developed based on a thermodynamic framework,in which a set of microforces is introduced to construct the constitutive relation and evolution *** the flexoelectric part of electric enthalpy,the strain gradient is determined by interpolating the mechanical strain at the node via the values of Gaussian integration points in the isoparametric *** model is shown to be capable of reproducing the classic analytical solution of dielectric materials incorporating the flexoelectric *** model is verified by duplicating some typical phenomena in flexoelectricity in cylindrical tubes and truncated pyramids.A comparison is made between the polarization distribution in dielectrics and *** model can reproduce the solution to the boundary value problem of the cylindrical flexoelectric tube,and demonstrate domain twisting at domain walls in ferroelectrics considering the flexoelectric effect.

关键词： Flexoelectricity Phase-field method Ferroelectrics Domain configuration

Automated Machine Learning Algorithm Using Recurrent Neural Network to Perform Long-Term Time Series Forecasting

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Computers, Materials & Continua 2024年第3期78卷 3529-3549页

作者： Ying su Morgan C.Wang shuai Liu Department of Statistics and Data Science University of Central FloridaOrlandoFL32816-2370USA School of Mathematics and Statistics Beijing Technology and Business UniversityBeijing100048China

Long-term time series forecasting stands as a crucial research domain within the realm of automated machine learning(AutoML).At present,forecasting,whether rooted in machine learning or statistical learning,typically relies on expert input and necessitates substantial manual *** manual effort spans model development,feature engineering,hyper-parameter tuning,and the intricate construction of time series *** complexity of these tasks renders complete automation unfeasible,as they inherently demand human intervention at multiple *** surmount these challenges,this article proposes leveraging Long Short-Term Memory,which is the variant of Recurrent Neural Networks,harnessing memory cells and gating mechanisms to facilitate long-term time series ***,forecasting accuracy by particular neural network and traditional models can degrade significantly,when addressing long-term time-series ***,our research demonstrates that this innovative approach outperforms the traditional Autoregressive Integrated Moving Average(ARIMA)method in forecasting long-term univariate time *** is a high-quality and competitive model in time series prediction,and yet it requires significant preprocessing *** multiple accuracy metrics,we have evaluated both ARIMA and proposed method on the simulated time-series data and real data in both short and long ***,our findings indicate its superiority over alternative network architectures,including Fully Connected Neural Networks,Convolutional Neural Networks,and Nonpooling Convolutional Neural *** AutoML approach enables non-professional to attain highly accurate and effective time series forecasting,and can be widely applied to various domains,particularly in business and finance.

关键词： Automated machine learning autoregressive integrated moving average neural networks time series analysis

Performance evaluation for multi-target tracking with temporal dimension specifics

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Chinese Journal of Aeronautics 2024年第2期37卷 446-458页

作者： Zhenzhen su Hongbing ji Cong TIAN Yongquan ZHANG School of Computer Science and Technology Xidian UniversityXi’an 710071China School of Electronic Engineering Xidian UniversityXi’an 710071China

With the great development of Multi-Target Tracking(MTT)technologies,many MTT algorithms have been proposed with their own advantages and *** to the fact that requirements to MTT algorithms vary from the application scenarios,performance evaluation is significant to select an appropriate MTT algorithm for the specific application *** this paper,we propose a performance evaluation method on the sets of trajectories with temporal dimension specifics to compare the estimated trajectories with the true *** proposed method evaluates the estimate results of an MTT algorithm in terms of tracking accuracy,continuity and ***,its computation is based on a multi-dimensional assignment problem,which is formulated as a computable form using linear *** enhance the influence of recent estimated states of the trajectories in the evaluation,an attention function is used to reweight the trajectory errors at different time ***,simulation results show that the proposed performance evaluation method is able to evaluate many aspects of the MTT *** evaluations are worthy for selecting suitable MTT algorithms in different application scenarios.

关键词： Multi-target tracking Temporal dimension specifics Performance evaluation Random finite sets Linear programming

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Role of catalyst surface-active sites in the hydrogenation ofα,β-unsaturated aldehyde

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 41-69页

作者： Haixiang Shi Tongming su Zuzeng Qin Hongbing ji School of Chemistry and Chemical Engineering Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification TechnologyGuangxi UniversityNanning 530004China Zhejiang Green Petrochemical and Light Hydrocarbon Transformation Research Institute Zhejiang University of TechnologyHangzhou 310014China

As an important technology in fine chemical production,the selective hydrogenation ofα,β-unsaturated aldehydes has attracted much attention in recent *** the process ofα,β-unsaturated aldehyde hydrogenation,a conjugated system is formed between>C=CC=O,leading to hydrogenation at both ends of the conjugated system,which competes with each other and results in more complex ***,improving the reaction selectivity is also difficult in industrial ***,many researchers have reported that surface-active sites on catalysts play a crucial role inα,β-unsaturated aldehyde *** review attempts to summarize recent advances in understanding the effects of surface-active sites(SASs)over metal catalysts for enhancing the process of *** construction strategies and roles of SASs for hydrogenation catalysts are *** attention has been given to the adsorption configuration and transformation mechanism ofα,β-unsaturated aldehydes on catalysts,which contributes to understanding the relationship between SASs and hydrogenation *** addition,recent advances in metal-supported catalysts for the selective hydrogenation ofα,β-unsaturated aldehydes to understand the role of SASs in hydrogenation are briefly ***,the opportunities and challenges will be highlighted for the future development of the precise construction of SASs.

关键词： α,β-unsaturatedd aldehydes hydrogenation active site cinnamaldehyde

Wave interaction for a generalized higher-dimensional Boussinesq equation describing the nonlinear Rossby waves

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Journal of Oceanology and Limnology 2024年第5期42卷 1415-1424页

作者： Rong su Penghao ji Xiaojun YIN College of Science Inner Mongolia Agricultural UniversityHohhot 010018China

Based on an algebraically Rossby solitary waves evolution model,namely an extended(2+1)-dimensional Boussinesq equation,we firstly introduced a special transformation and utilized the Hirota method,which enable us to obtain multi-complexiton solutions and explore the interaction among the *** wave functions are then employed to infer the influence of background flow on the propagation of Rossby waves,as well as the characteristics of propagation in multi-wave running ***,we generated stereogram drawings and projection figures to visually represent these *** dynamical behavior of these solutions is thoroughly examined through analytical and graphical ***,we investigated the influence of the generalized beta effect and the Coriolis parameter on the evolution of Rossby waves.

关键词： Rossby wave Boussinesq equation Complexiton solution Breather solution

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Intermetallic Compounds Formation in Dissimilar Friction Stir Welding of Mg/Cu Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1523-1532页

作者： Xue Li Qingzhen Zhao Hao su ji Chen Chuansong Wu MOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing Institute of Materials JoiningShandong UniversityJinan250061China

Joining dissimilar Mg/Cu alloys was still an intractable problem because of the excessive intermetallic compounds(IMCs)and poor mechanical properties using conventional welding *** the present study,friction stir welding was employed for the butt joining of dissimilar AZ31B Mg-alloy and T2 pure Cu ***-free Mg/Cu joints were obtained with Mg-RS and Cu-AS configuration,at a welding speed of 50 mm/min and tool rotating speeds of 325 r/min,625 r/min and 925 r/*** the joining interface,both Mg_(2)Cu and MgCu_(2) IMC phases were observed,with a clear,uniform and continuous IMCs layer composed of two sub-layers,layer-A of Mg+Mg_(2)Cu and layer-B of Mg_(2)Cu+MgCu_(2).The maximum ultimate tensile strength of the Mg/Cu friction stir welding joint reached 130 MPa at 925 r/min due to enhanced mechanical interlocking between Mg and Cu,as well as sufficient metallurgical bonding at the joining interface with an IMCs layer thickness in the range of 1.0-2.0μm.

关键词： Friction stir welding Magnesium Copper Intermetallic compounds Mechanical properties

Seasonality regulates the effects of resource addition on plant diversity and ecosystem functioning in semi-arid grassland

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Journal of Plant Ecology 2021年第6期14卷 1143-1157页

作者： Feng-Wei Xu jian-Jun Li ji-shuai su Xiao-Ming Lu Yang Wang Li-ji Wu Chao-Nan Wang Di-Ma Chen Yong-Fei Bai State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China Research Institute of Forestry Chinese Academy of ForestryBeijing 100091China Grassland Research Center National Forestry and Grassland AdministrationBeijing 100091China Collaborative Innovation Center of jiangxi Typical Trees Cultivation and Utilization College of ForestryJiangxi Agricultural UniversityNanchang 330045China College of Biological and Pharmaceutical Sciences China Three Gorges UniversityYichang 443002China College of Lifesciences University of Chinese Academy of SciencesBeijing 100049China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Aims Seasonal variations in species richness,aboveground net primary productivity(ANPP)and stability under resource enrichment are frequently *** study explores how the impacts of resource enrichment on species richness,ANPP and stability vary among seasons in semi-arid *** We conducted a 3-year experiment in an Inner Mongolia grassland to determine the effects of resource input(water[W],nitrogen[N])on species richness,community ANPP and stability using seasonal sampling during the growing season(2013–2015).Structural equation modeling(SEM)was used to examine the relative importance of resource input on community stability via mechanistic pathways in each month and the whole growing *** Findings Resource inputs did not affect community ANPP in May and June,while N and/or NW enhanced ANPP in July and *** inputs generally did not affect species richness,asynchrony or community stability in most of the *** responses of perennial bunchgrasses(PB)to N and/or NW treatments contributed to the increased community ANPP in July and *** asynchrony may be the major mechanism contributing to community stability in May and June and the entire growing season,and PB stability is potentially the primary factor controlling community stability in July and August under resource *** results indicate that season and resource availability could interact to regulate species richness,community ANPP and stability in semi-arid *** findings have important implications for management practices in semi-arid grasslands in order to mitigate the impact of land use and global change.

关键词： season resource enrichment species richness aboveground net primary productivity(ANPP) community stability plant functional groups

Facile synthesis of hierarchical NiO/NiFe_(2)O_(4) microsphere composite as efficient visible photocatalyst for 2,4-DCP degradation

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Rare Metals 2024年第4期43卷 1580-1588页

作者： Shabana Shaheen shuai Xu ji Bian Amir Zada Zi-Qing Zhang Yang Qu Li-Qiang jing Key Laboratory of Functional Inorganic Materials Chemistry(Ministry of Education) International Joint Research Center and Lab for Catalytic TechnologySchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin150080China Department of Chemistry Abdul Wali Khan UniversityMardan23200Pakistan

It is highly desired to develop efficient photocatalysts with recycling property for practical application to degrade toxic ***,nanosheet-assembled NiFe_(2)O_(4)microspheres with commendable activity are successfully synthesized by a facile solvothermal reaction with NH4F as the modifier,and their photoactivities are further improved by coupling with NiO through an in situ growth *** optimized nickel oxide(NiO)/nickel ferrite(NiFe_(2)O_(4))microsphere composite(5NiO/NFO-4)exhibits a satisfactory photocatalytic activity for 2,4-dichlorophenol(2,4-DCP)degradation under visible-light irradiation,which is attributed to its wide visible-light response,well-designed hierarchical structure and enhanced charge transfer and separation by coupling NiO as a high-level energy platform to accept ***,it is found that the NiO/NiFe_(2)O_(4)microsphere photocatalysts can be easily collected and recycled owing to the distinctive magnetic *** work provides a feasible route to rational design visible-light-driven photocatalysts with high-activity for environmental remediation and purification with good recyclability.

关键词： NiFe_(2)O_(4) microspheres NiO/Fe_(2)O_(4) composite Charge separation Visible-light photocatalysis 2 4-Dichlorophenol degradation

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