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Adaptive neural network control of a 2-DOF helicopter system considering input constraints and global prescribed performance

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Science c.ina(Information Sciences) 2024年第7期67卷 224-239页

作者： Zhijia ZHAO Jiale wu Zhijie LIU We HE c.L.Philip cHEN School of Mechanical and Electrical Engineering Guangzhou University School of Intelligence Science and Technology and Key Laboratory of Intelligent Bionic.unmanned Systems of Ministry of Education University of Science and Technology Beijing School of computer Science and Engineering South China University of Technology Pazhou Lab

In this study, an adaptive neural network(NN) control is proposed for nonlinear two-degree-offreedom(2-DOF) helicopter systems considering the input constraints and global prescribed ***, radial basis function NN(RBFNN) is employed to estimate the unknown dynamics of the helicopter system. Second, a smooth nonaffine function is exploited to approximate and address nonlinear constraint functions. Subsequently, a new prescribed function is proposed, and an original constrained error is transformed into an equivalent unconstrained error using the error transformation and barrier function transformation methods. The analysis of the established Lyapunov function proves that the controlled system is globally uniformly bounded. Finally, the simulation and experimental results on a constructed Quanser's test platform verify the rationality and feasibility of the proposed control.

关键词： adaptive NN control 2-DOF helicopter global prescribed performance input constraints

Liquefaction susceptibility and deformation characteristics of saturated coral sandy soils subjected to cyclic loadings-a critical review

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 261-296页

作者： chen Guoxing Qin You Ma Weijia Liang Ke wu Qi c.Hsein Juang Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing 210009China civil Engineering and Earthquake Disaster Prevention center of Jiangsu Province Nanjing 210009China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China college of civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 210016China Glenn Department of civil Engineering Clemson UniversityClemsonSC 29634USA

coral sandy soils widely exist in coral island reefs and seashores in tropical and subtropical *** to the unique marine depositional environment of coral sandy soils,the engineering characteristics and responses of these soils subjected to monotonic and cyclic loadings have been a subject of intense interest among the geotechnical and earthquake engineering *** paper critically reviews the progress of experimental investigations on the undrained behavior of coral sandy soils under monotonic and cyclic loadings over the last three *** focus of coverage includes the contractive-dilative behavior,the pattern of excess pore-water pressure(EPWP)generation and the liquefaction mechanism and liquefaction resistance,the small-strain shear modulus and strain-dependent shear modulus and damping,the cyclic softening feature,and the anisotropic characteristics of undrained responses of saturated coral sandy *** particular,the advances made in the past decades are reviewed from the following aspects:(1)the characterization of factors that impact the mechanism and patterns of EPWP build-up;(2)the identification of liquefaction triggering in terms of the apparent viscosity and the average flow coefficient;(3)the establishment of the invariable form of strain-based,stress-based,or energy-based EPWP ratio formulas and the unique relationship between the new proxy of liquefaction resistance and the number of cycles required to reach liquefaction;(4)the establishment of the invariable form of the predictive formulas of small strain modulus and strain-dependent shear modulus;and(5)the investigation on the effects of stress-induced anisotropy on liquefaction susceptibility and dynamic deformation *** gained through the critical review of these advances in the past decades offer a perspective for future research to further resolve the fundamental issues concerning the liquefaction mechanism and responses of coral sandy sites subjecte

关键词： liquefaction susceptibility dynamic deformation characteristics coral sandy soil cyclic loading review and prospect

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.Huang K.Jiang c.N.wu H.Peng P.c.hen R.Li H.B.Zhuo c.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Single-cell RNA sequencing facilitates the elucidation of the complete biosynthesis of the antidepressant hyperforin in St. John's wort

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Molecular Plant 2024年第9期17卷 1439-1457页

作者： Song wu Ana Luisa Malaco Morotti Jun Yang Ertao Wang Evangelos c.Tatsis National Key Laboratory of Plant Molecular Genetics CASs Center for Excellence in Molecular Plant SciencesShanghai lnstitute of Plant Physiology and EcologyChineseAcademy of SciencesShanghai 200032China university of c.inese Academy of Sciences Shanghai 200032China UEPAMS-cAS-JIcs centre of Excellencefor Plant anamlcroblalSclence Snangnal 200032Cnina

Hyperforin is the compound responsible for the effectiveness of ***'s wort(Hypericum perforatum)as an antidepressant,but its complete biosynthetic pathway remains *** discovery based on co-expression analysis of bulk RNA-sequencing data or genome mining failed to discover the missing steps in hyperforin *** this study,we sequenced the 1.54-Gb tetraploid *** genome assem-bled into 32 chromosomes with the scaffold N50 value of 42.44 *** single-cell RNA sequencing,we iden-tified a type of cell,“Hyper cells”,wherein hyperforin biosynthesis de novo takes place in both the leaves and *** pathway reconstitution in yeast and tobacco,we identified and characterized four transmembrane prenyltransferases(HpPT1-4)that are localized at the plastid envelope and complete the hyperforin biosynthetic *** hyperforin polycyclic scaffold is created by a reaction cascade involving an irregular isoprenoid coupling and a tandem *** findings reveal how and where hy-perforin is biosynthesized,enabling synthetic-biology reconstitution of the complete ***,this study not only deepens our comprehension of specialized metabolism at the cellularlevel but also provides strategic guidance for elucidation of the biosynthetic pathways of other specializied metabolites in plants.

关键词： hyperforin Hypericum perforatum de novo genome sequencing single-cell RNA sequencing biosyn-thetic pathway meroterpenoids

Review of Networked Microgrid Protection:Architectures,challenges,Solutions,and Future Trends

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cSEE Journal of Power and Energy Systems 2024年第2期10卷 448-467页

作者： Jorge de la cruz Ying wu John E.candelo-Becerra Juan c.Vasquez Josep M.Guerrero center for Research on Microgrids(cROM) Department of Energy TechnologyAalborg University9220 AalborgDenmark Facultad de Minas Departamento de Energia Eléctrica y AutomaticaUniversidad Nacional de ColombiaSede MedellinCarrera 80 No.65-223RobledoMedellin 050041Colombia. center for Research on Microgrids at UPc(UPc cROM) Department of Electronic EngineeringTechnical University of Catalonia(UPC)08019 Barcelona Spain IcREA Pg.Lluis Companys 2308010 BarcelonaSpain center for Research on Microgrids at AAU(AAU cROM) AAU EnergyAalborg University(AAU)9220 Aalborg EastDenmark

Design and selection of advanced protection schemes have become essential for reliable and secure operation of networked *** protection schemes that allow correct operation of microgrids have been proposed for individual systems in different topologies and ***,protection schemes for networked microgrids are still in devel-opment,and further research is required to design and operate advanced protection in interconnected *** of these microgrids in different nodes with various intercon-nection technologies increases fault occurrence and complicates protection *** paper aims to point out challenges in developing protection for networked microgrids,potential solutions,and research areas that need to be addressed for their ***,this article presents a systematic analysis of different microgrid clusters proposed since 2016,including several architectures of networked microgrids,operation modes,components,and utilization of renewable sources,which have not been widely explored in previous review ***,the paper presents a discussion on protection systems currently available for microgrid clusters,current challenges,and solutions that have been proposed for these ***,it discusses the trend of protection schemes in networked microgrids and presents some conclusions related to ***—Adaptive eprotection,microgrid cluster,microgrid,multiple microgrid,networked microgrid,real-time simulation,smart grid.

关键词： Adaptive eprotection microgrid cluster microgrid multiple microgrid networked microgrid real-time simulation smart grid

Boron neutron capture therapy of cancer:where do we stand now?

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cancer communications 2024年第8期44卷 889-892页

作者： Rolf F.Barth Gong wu Maria da Graca H.Vicente John c Grecula Nilendu Gupta Department of Pathology The Ohio State UniversityColumbusOhioUSA Mass Spectrometry and Proteomics Facility The Ohio State UniversityColumbusOhioUSA Department of chemistry Louisiana State UniversityBaton RougeLouisianaUSA Department of Radiation Oncology The Ohio State UniversityColumbusOhioUSA

1 INTRODUcTION,This is the third Editorial/commentary that one of us(***)has written relating to boron neutron capture therapy(BNcT)[1,2].For those readers who are unfamiliar with BNcT we would refer them to several recent comprehensive reviews[3–5].The second Editorial ended on a hopeful note that with the introduction of acceleratorbased neutron sources(ABNSs),BNcT would enter into the mainstream of radiation therapy[2].

关键词： boron 1,2 neutron

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang wu Jia Qu Lin-zhi wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inc.ination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Resilience-incorporated seismic risk assessment of precast concrete frames with“dry”connections

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 403-425页

作者： wu chenhao Tang Yuchuan cao Xuyang wu Gang Key Laboratory of concrete and Prestressed concrete Structures of the Ministry of Education Nanjing 211102China Department of civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095USA School of civil Engineering Southeast UniversityNanjing 211102China college of civil and Transportation Engineering Hohai UniversityNanjing 210024China

A resilience-incorporated risk assessment framework is proposed and demonstrated in this study to manifest the advantageous seismic resilience of precast concrete frame(PcF)structures with“dry”connections in terms of their low damage and rapid *** framework integrates various uncertainties in the seismic hazard,fragility,capacity,demand,loss functions,and post-earthquake *** this study,the PcF structures are distinguished from ordinary reinforced concrete frame(RcF)structures by characterizing multiple limit states for the PcF based on its unique damage ***,probabilistic story-wise pushover analyses are performed to yield story-wise capacities for the predefined limit *** the seismic resilience analysis,a step-wise recovery model is proposed to idealize the functionality recovery process,with separate considerations of the repair and non-repair *** recovery model leverages the economic loss and downtime to delineate the stochastic post-earthquake recovery curves for the resilience loss *** such,contingencies in the probabilistic post-earthquake repairs are incorporated and the empirical judgments on the recovery parameters are largely *** proposed framework is demonstrated through a comparative study between two“dry”connected PcFs and one RcF designed as alternative structural systems for a prototype *** results from the risk quantification indicate that the PcFs show reduced loss hazards and lower expected losses relative to the ***,the PcF equipped with energy dissipation devices at the“dry”connections largely reduces the expected economic loss,downtime,and resilience loss by 29%,56%,and 60%,respectively,compared to the RcF.

关键词： precast concrete frame non-emulative precast system seismic resilience seismic risk functional recovery

New findings on the influence of El Nino events on tropical cyclone formation

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Science c.ina Earth Sciences 2024年第3期67卷 892-893页

作者： Liguang wu Department of Atmospheric and Oceanic Sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China

Tropical cyclones typically form over warm tropical and subtropical ocean surfaces, as their formation and intensification rely primarily on the energy provided by the ocean. Pioneering research by Gray (1968) revealed that the formation of tropical cyclones requires the sea surface temperature (SST) to be no less than 26.5℃. consequently, SST is commonly recognized as a crucial parameter among the environmental factors influencing tropical cyclone formation(Gray, 1979;Emanuel and Nolan, 2004).

关键词： tropical cyclone ocean