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Fixed-Time Cluster Optimization for Multi-Agent Systems Based on Piecewise Power-Law Design

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1301-1303页

作者： Suna Duan Xinchun Jia xiaobo Chi School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Automation and Software Engineering Shanxi UniversityTaiyuan 030013China

Dear Editor,This letter focuses on the fixed-time(FXT)cluster optimization problem of first-order multi-agent systems(FOMASs)in an undirected network,in which the optimization objective is the sum of the objective functions of all clusters.A novel piecewise power-law control protocol with cooperative-competition relations is ***,a sufficient condition is obtained to ensure that the FOMASs achieve the cluster consensus within an FXT.

关键词： agent cluster optimization

No basalt accumulation and segregation atop the 660-km discontinuity beneath the Sea of Okhotsk

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Earth and Planetary Physics 2024年第4期8卷 621-631页

作者： BingXin Zhou xiaobo He Marine Science and Technology College Zhejiang Ocean UniversityZhoushan Zhejiang 316022China

Recent seismic evidence shows that basalt accumulation is widespread in the mantle transition zone(MTZ),yet its ubiquity or sporadic nature remains *** investigate this phenomenon further,we characterized the velocity structure across the 660-km discontinuity that separates the upper mantle from the lower mantle beneath the Sea of Okhotsk by modeling the waveform of the S660P phase,a downgoing S wave converting into a P wave at the 660-km *** waves were excited by two regional>410-km-deep events and were recorded by stations in central *** findings showed no need to introduce velocity anomalies at the base of the MTZ to explain the S660P waveforms because the IASP91 model adequately reproduced the *** finding indicates that the basalt accumulation has not affected the bottom of the MTZ in the study ***,this discontinuity is primarily controlled by temperature or water content variations,or ***,we argue that the basalt accumulation at the base of the MTZ is sporadic,not ubiquitous,reflecting its heterogeneous distribution.

关键词： 660-km discontinuity S660P basalt segregation mantle transition zone western Pacific subduction zone

Single-atom catalysis:a promising avenue for precisely controlling reaction pathways

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 97-120页

作者： xiaobo Yang Xuning Li Yanqiang Huang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Single-atom catalysts (SACs), characterized by exceptionally high atom efficiency, have garnered significant attention across various catalytic reactions. Recent studies have showcased SACs with robust capabilities for precise catalysis, specifically targeting reactions along designated pathways. This review focuses on the advances in the precise activation and reconstruction of chemical bonds on SACs, including precise activation of C–O and C–H bonds and selective couplings involving C–C and C–N bonds. Our discussion begins with a thorough exploration of the factors that render SACs skilled in precise catalytic processes, encompassing the narrow d-band electronic state of single atom site resulting in the adsorption tendency, isolate site resulting in unique adsorption structure, and synergy effect of a single atom site with its neighbors. Subsequently, we elaborate on the applications of SACs in electrocatalysis and thermocatalysis including four prominent reactions, namely, electrochemical CO_(2) reduction, urea electrochemical synthesis, CO_(2) hydrogenation, and CH4 activation. Then the concept of rational design of SACs for precisely controlling reaction pathways is discussed from the aspects of pore structure design, support-metal strong interaction, and support hydrophilic/hydrophobic. Finally, we summarize the challenges encountered by SACs in the field of precise catalytic processes and outline prospects for their further development in this domain.

关键词： single atom catalysts selective oxidation CO_(2)RR bond coupling

Spectral purification improves monitoring accuracy of the comprehensive growth evaluation index for film-mulched winter wheat

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Journal of Integrative Agriculture 2024年第5期23卷 1523-1540页

作者： Zhikai Cheng xiaobo Gu Yadan Du Zhihui Zhou Wenlong Li xiaobo Zheng Wenjing Cai Tian Chang Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid AreasMinistry of Education/Northwest A&F University Yangling712100China

In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter *** on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral *** machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried *** results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth *** accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of *** purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral *** results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.

关键词： mulched winter wheat machine learning fuzzy comprehensive evaluation comprehensive growth evaluation index unmanned aerial vehicle

Advances in friction of aluminium alloy deep drawing

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Friction 2024年第3期12卷 396-427页

作者： Yiren GAO Hongxia LI Danyang ZHAO Minjie WANG xiaobo FAN School of Mechanical Engineering Dalian University of TechnologyDalian 116023China

Broad use of lightweight aluminium alloy parts in automobile manufacturing,aerospace,electronic communication,and rail transit is mainly formed through deep drawing *** drawing friction is a key boundary condition for controlling the forming quality of aluminium alloy ***,due to the oxidation and adhesion tendency of aluminium alloys,the tribological situations of aluminium alloy deep drawing(AADD)system is more complicated than those of traditional deep drawing of steel ***,the study of AADD friction is essential for manufacturing high-performance aluminium alloy ***,aiming to provide a valuable reference for researchers in related fields,a comprehensive review of AADD friction is provided,including friction mechanism,influencing factors,friction measurement,friction model,friction simulation,and lubrication-free friction ***,a brief conclusion and several current challenges were discussed.

关键词： aluminium alloy deep drawing(AADD) influencing factors friction measurement friction model friction control

Dix-Type Multi-Component Scholte Wave Dispersion Inversion without Initial Model

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Journal of Earth Science 2024年第4期35卷 1393-1396页

作者： Linjing Zhao Xiangchun Wang xiaobo Liu School of Geophysics and Information Technology China University of GeosciencesBeijing 100083China Key Laboratory of Intraplate Volcanoes and Earthquakes Ministry of EducationChina University of GeosciencesBeijing 100083China School of Ocean Sciences China University of GeosciencesBeijing 100083China Key Laboratory of Polar Geology and Marine Mineral Resources Ministry of EducationChina University of GeosciencesBeijing 100083China

0 INTRODUCTION Scholte wave dispersion curves contain rich information regarding seafloor media and have therefore attracted increasing attention(Wang et al.,2022;Dong et al.,2021;Du et al.,2020).Ocean bottom seismometer(OBS)data are widely used in the study of seafloor medium information(Wang et al.,2024),and contain rich surface wave information.

关键词： seafloor wave Inversion

Preface of the Special Issue on Symplectic Geometry and Mathematical Physics

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Acta Mathematica Sinica,English Series 2024年第1期40卷 1-2页

作者： Huijun Fan xiaobo Liu Gang Tian Peking University BeijingChina

Symplectic geometry is a branch of differential geometry and differential topology and has its origins in the Hamiltonian formulation of classical *** the last few decades,symplectic geometry has experienced enormous progress and has had interactions with many other branches of mathematics,including enumerative geometry,low-dimensional topology,mathematical physics,Hamiltonian dynamics,integrable systems etc..

关键词： geometry topology Hamiltonian

Collaborative positioning for swarms:A brief survey of vision,LiDAR and wireless sensors based methods

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Defence Technology（防务技术） 2024年第3期33卷 475-493页

作者： Zeyu Li Changhui Jiang xiaobo Gu Ying Xu Feng zhou Jianhui Cui College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao266590China Geoloc Laboratory Universite Gustave EiffelParis77454France School of Automation Guangdong University of TechnologyGuangzhou510006China

As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other *** receiving spatial information from both its environment and other agents,an agent can use various methods and sensor types to localize *** its high flexibility and robustness,collaborative positioning has become a widely used method in both military and civilian *** paper introduces the basic fundamental concepts and applications of collaborative positioning,and reviews recent progress in the field based on camera,LiDAR(Light Detection and Ranging),wireless sensor,and their *** paper compares the current methods with respect to their sensor type,summarizes their main paradigms,and analyzes their evaluation ***,the paper discusses the main challenges and open issues that require further research.

关键词： Collaborative positioning Vision LiDAR Wireless sensors Sensor fusion

Repair of Second-Generation Recycled Fine Aggregate of Waste Concrete from Freeze-Thaw Environment by Carbonation Treatment

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Journal of Renewable Materials 2024年第1期12卷 187-201页

作者： Jie Huang Rongbin Jiang xiaobo Sun Yingyong Shuai School of Building Engineering Taizhou Polytechnic CollegeTaizhou225300China

The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of *** study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)*** and after carbonation,the properties of SRFA were *** second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was *** results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II *** micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,*** the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually *** treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.

关键词： Carbonation treatment repair freeze-thaw cycles second-generation recycled fine aggregate