检索结果-南通市图书馆

Attitude control of multi-spacecraft systems on SO(3)with stochastic links failure

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Aeronautics 2024年第3期37卷 320-331页

作者： KANG Zeyu SHEN Qiang WU Shufan Chris j.DAMAREN MU Zhongcheng School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Institute for Aerospace Studies University of TorontoTorontoOntario M3H 5T6Canada

In this paper,for Multi-Spacecraft System(MSS)with a directed communication topology link and a static virtual leader,a controller is proposed to realize attitude consensus and attitude stabilization with stochastic links failure and actuator ***,an MSS attitude error model suitable for a directed topology link and with a static virtual leader based on SO(3)is derived,which considers that the attitude error on SO(3)cannot be defined based on algebraic ***,we design a controller to realize the MSS on SO(3)with attitude consensus and attitude stabilization under stochastic links failure and actuator ***,the simulation results of a multi-spacecraft system with stochastic links failure and a static virtual leader spacecraft are demonstrated to illustrate the efficiency of the attitude controller.

关键词： Multi-spacecraft systems Attitude consensus Attitude stabilization Stochastic links failure Super-martingale convergence

Universal insertion of molecules in ionic compounds under pressure

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng Yanming Ma Chris j.Pickard Hanyu Liu Maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State Key Laboratory of Superhard Materials & Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of Materials Science & Metallurgy University of Cambridge Advanced Institute for Materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

Development of a toroidal soft x-ray imaging system and application for investigating three-dimensional plasma on j-TEXT

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第3期26卷 94-99页

作者：赵传旭李建超张晓卿王能超丁永华杨州军江中和严伟李杨波毛飞越任正康 the j-TEXT Team International joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic Engineering and School of PhysicsHuazhong University of Science and TechnologyWuhan 430074People's Republic of China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan 430205People's Republic of China International joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China

A toroidal soft x-ray imaging(T-SXRI)system has been developed to investigate threedimensional(3D)plasma physics on *** T-SXRI system consists of three sets of SXR *** sets are newly developed and located on the vacuum chamber wall at toroidal positionsφof 126.4°and 272.6°,respectively,while one set was established previously atφ=*** set of SXR arrays consists of three arrays viewing the plasma poloidally,and hence can be used separately to obtain SXR images via the tomographic *** sawtooth precursor oscillations are measured by T-SXRI,and the corresponding images of perturbative SXR signals are successfully reconstructed at these three toroidal positions,hence providing measurement of the 3D structure of precursor *** observed 3D structure is consistent with the helical structure of the m/n=1/1 *** experimental observation confirms that the T-SXRI system is able to observe 3D structures in the j-TEXT plasma.

关键词： SXR imaging j-TEXT tokamak three-dimensional measurement MHD

Cultural Exclusion and the Transformation of the Cultural Landscape: The Origins of Anti-Chinese Racism in Canada

在线全文

学校读者我要写书评

暂无评论

Social Sciences in China 2024年第3期45卷 181-202页

作者： Timothy j.Stanley Faculty of Education University of Ottawa

Anti-Chinese racism in Canada is a social structure of racialized exclusion that over time came to be built into the settler colonialism that continues to shape the *** of European,and especially of British and French origins,have consequently created the cultural landscapes that constitute the country(i.e.,its material constructions and dominant cultural overlays).When read against these landscapes,people of Chinese origins and members of other racialized groups continue to be positioned as aliens who do not belong in the country in way in which people racialized as white are *** on British Columbia(BC),Canada's westernmost province,and the historical activity of people of Chinese origins,this paper traces the history of anti-Chinese racism and its links to Anglo-Canadian settler *** has long been linked to China,and the Chinese entered BC at the same time as Europeans before the country *** this,Chinese people have repeatedly been positioned as threats to Anglo-Canadian dominance,and especially to control over the land and its *** Canadian resistance to racist exclusions,along with that of other groups,has led to the elimination of legislated ***,historic exclusions continue to shape cultural landscapes and popular understandings of who belongs and who does *** these landscapes requires an antiracist project of pursuing common projects that cross over racialized differences to remake the territory in ways that affirm the presence of all the peoples of Canada.

关键词： Chinese Canadians cultural exclusion white supremacy racism

Impact of device resistances in the performance of graphene‑based terahertz photodetectors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2024年第2期17卷 87-97页

作者： O.Castelló Sofía M.López Baptista K.Watanabe T.Taniguchi E.Diez j.E.Velázquez-Pérez Y.M.Meziani j.M.Caridad j.A.Delgado-Notario Department of Applied Physics University of Salamanca37008 SalamancaSpain Unidad de Excelencia en Luz y Materia Estructurada(LUMES) University of Salamanca37008 SalamancaSpain Research Center for Electronic and Optical Materials National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Nanotechnology Group USAL-NanolabUniversity of Salamanca37008 SalamancaSpain

In recent years,graphene field-effect-transistors(GFETs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and *** features are essential to enable emerging THz applications,including 6G wireless communications,quantum information,bioimaging and ***,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic *** this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFET *** dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,*** results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical *** findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.

关键词： Graphene THz Photodetector Field-effect transistor Plasmonic

Modelling dynamic pantograph loads with combined numerical analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Railway Engineering Science 2024年第1期32卷 81-94页

作者： F.F.jackson R.Mishra j.M.Rebelo j.Santos P.Antunes j.Pombo H.Magalhaes L.Wills M.Askill School of Computing and Engineering University of HuddersfieldHuddersfieldUK School of Computing and Engineering Institute of Railway ResearchUniversity of HuddersfieldHuddersfieldUK IDMEC Instituto Superior TecnicoUniversidade de LisboaLisbonPortugal ISEL Instituto Politecnico de LisboaLisbonPortugal Hitachi Rail Newton AycliffeUK Wabtec/Brecknell Willis ChardUK

Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric *** heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational *** research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact ***,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 *** an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph *** the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph *** results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.

关键词： Pantograph-catenary interaction Pantograph aerodynamics Computational fluid dynamics Pantograph loads Current collection performance

Editorial for the Special Issue on Emerging Technology and Advanced Application of Nondestructive Detection for Power Equipment

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Electrical Engineering 2024年第1期10卷 1-2页

作者： Li j. Mei H. Li S. Tianjin University China Tsinghua Shenzhen International Graduate School China Lanzhou jiaotong University China

The rapid development of clean and renewable energy technologies represented by wind and solar energy,as well as the continuous growth of load demand,have put forward higher requirements for the safe operation of the power *** performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding,transportation,assembly,and operation,which cannot meet the reliability requirements of power systems in the new *** detection is an essential technical method in industrial development,which can detect and evaluate the defect and damage status of in-service equipment,key components,and materials without damaging the object.

关键词： service Application operation

A quantitative analysis of the US materials flow methodology and comparison to the EU methodology for MSW statistics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Waste Disposal and Sustainable Energy 2024年第1期6卷 85-94页

作者： Demetra Tsiamis Fabio Poretti Stefano Consonni Marco j.Castaldi Earth Engineering Center Department of Chemical EngineeringThe City College of New YorkNew YorkNYUSA Dipartimento Di Energetica Politecnico Di MilanoPiazza Leonardo da Vinci 3220133MilanItaly

The European Union(EU)and the United States(US)determine municipal solid waste(MSW)statistics *** EU applies a site-specific methodology that directly measures waste whereas the US employs a materials flow methodology that estimates MSW statistics indirectly based on production and recovery data from *** study dissects the materials flow methodology and presents quantitative materials flow Sankey diagrams for the primary MSW materials to highlight data gaps that can be addressed to improve the methodology’s *** industry plastics data were applied to the materials flow methodology,and the results were within 10%of the plastics statistics reported by the US Environmental Protection Agency(US EPA).Drawbacks to the methodologies include EU measurement inaccuracies due to double-counting and not accounting for residual waste in the *** latter may partially explain why landfilling tonnages reported by the US EPA were approximately 60%less than the tonnages reported by the Waste to Energy Research and Technology Council(WTERT)in its national MSW survey that applied the EU methodology in the *** the EU,there is no US national policy that requires states to measure and report state-level waste data to the US *** improvements in US MSW statistics rely heavily on the implementation of national policies to homogenize the measurement and collection of waste data from states.

关键词： Materials flow methodology Site-specific methodology United States European Union Municipal solid waste Discrepancy

Mathematical beauty and Palladian architecture:Measuring and comparing visual complexity and diversity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2024年第4期13卷 729-740页

作者： ju Hyun Lee Michael j.Ostwald School of Built Environment Faculty of ArtsDesign&ArchitectureThe University of New South WalesSydneyNSW 2052Australia

Palladio’s design principles,including proportion and harmony,have often been associated with mathematical definitions of ***,the geometric and semantic properties of his fac¸ades have rarely been analysed in a holistic *** is little evidence of how mathematical beauty may be embodied in his *** research investigates complexity(fractal dimension or D)and diversity(perplexity or PP)as aesthetic indices,aiming to capture distinct characteristics of Palladian *** D and PP values of 22 Palladian villa fac¸ades are measured and analysed,before being compared with those of three Renaissance facades by Sebastiano *** combination of D and PP captures the geometric and semantic aesthetic qualities of architectural ***,the developed scatter plot of D and PP results supports the identification of four distinct aesthetic types of Palladian fac¸ade *** novel combination of D and PP measures contributes to a better understanding of one definition of the mathematical beauty of architecture,wherein“the whole is other than the sum of the parts”in compositional terms(a famous Gestalt principle).Specifically,this research provides new mathematical insights into the visual character of Palladian architecture and compares two important measures thereof.

关键词： Palladian architecture Complexity Diversity Mathematical beauty Perplexity Fac¸ade design