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Distributed fixed-time observers for linear time-invariant systems

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Kongzh. yu j.ec./c.ntrol and Dec.sion 2024年第11期39卷 3664-3672页

作者： Zh.ng T. Wu h.-Y. Zh. Z.-h. Zh.ng X.-j. Guan Z.-h. Engineering Researc. c.nter for Metallurgic.l Automation and Measurement Tec.nology of Ministry of Educ.tion Wuhan University of Science and Technology Wuhan 430081 China Institute of Robotic. and Intelligent Systems Wuhan University of Science and Technology Wuhan 430081 China Sc.ool of Artific.al Intelligenc. and Automation Huazhong University of Science and Technology Wuhan 430074 China

A c.ass of distributed fixed-time c.nvergent observers is designed based on th. bi-limit weigh.ed h.mogeneous approximation th.ory and observability dec.mposition for th. distributed state estimation of linear time-invariant systems. Firstly, for a single-input-single-output integrating c.ain system, a c.ntralized fixed-time observer is designed for th. system using bi-limit weigh.ed h.mogeneous estimation. Th.n, th. linear time-invariant system is dec.mposed into observable and unobservable subsystems based on th. observability dec.mposition. Eac. agent in th. sensor network rec.nstruc.s loc.l observable sub-states in a fixed time based on th. c.ntralized observer by using only th. system output measurements, and th.n state information between th. agents is used to c.nstruc. a c.nsistent algorith. to estimate th. loc.l unobservable sub-states in a fixed time, th.s realizing state omnisc.enc. in a fixed time. Unlike previous works, th.s paper does not need to c.nstruc. a spec.fic.Lyapunov func.ion to give an expression for th. c.nvergenc. time. Finally, th. effec.iveness of th. designed observer is verified by simulations. © 2024 North.ast University. All righ.s reserved.

关键词： distributed estimation fixed-time observer linear systems observability dec.mposition sensor networks weigh.ed h.mogeneity

A Preliminary c.mparative Study on th. c.ntering Algorith.s for c.ssiniISS NAc.Images

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Researc. in Astronomy and Astroph.sic. 2024年第10期24卷 58-65页

作者： T.Liang Q.-F.Zh.ng G.-M.Liu W.-h.Zh. c.-S.Wang Department of c.mputer Sc.enc. Jinan UniversityGuangzhou 510632China Sino-Frenc. j.int Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China Sc.ool of c.mputer Sc.enc. Guangdong University of EducationGuangzhou 510303China

Obtaining h.gh.prec.sion is an important c.nsideration for astrometric.studies using images from th. Narrow Angle c.mera(NAc.of th. c.ssini Imaging Sc.enc. Subsystem(ISS).Selec.ing th. best c.ntering algorith. is key to enh.nc.ng astrometric.*** th.s study,we c.mpared th. ac.urac. of five c.ntering algorith.s:Gaussian fitting,th. modified moments meth.d,and th.ee point-spread func.ion(PSF)fitting meth.ds(effec.ive PSF(ePSF),PSFEx,and extended PSF(x PSF)from th. c.ssini Imaging c.ntral Laboratory for Operations(c.c.OPS)).We assessed th.se algorith.s using 70 ISS NAc.star field images taken with.c.1 and c.2 filters ac.oss different stellar *** ePSF meth.d c.nsistently demonstrated th. h.gh.st ac.urac.,ac.ieving prec.sion below 0.03 pixels for stars of magnitude *** to th. previously c.nsidered best,th. modified moments meth.d,th. e PSF meth.d improved overall ac.urac. by about 10%and 21%in th. sample and line direc.ions,***,th. xPSF model provided by c.c.OPS h.d lower prec.sion th.n th. ***,th. ePSF exh.bits an improvement in measurement prec.sion of 23%and 17%in th. sample and line direc.ions,respec.ively,over th. *** disc.epanc. migh. be attributed to th. xPSF foc.sing on ph.tometry rath.r th.n *** findings h.gh.igh. th. nec.ssity of c.nstruc.ing PSF models spec.fic.lly tailored for astrometric.purposes in NAc.images and provide guidanc. for enh.nc.ng astrometric.measurements using th.se ISS NAc.images.

关键词： meth.ds:analytic.l tec.niques:image proc.ssing stars:imaging astrometry

h.rnessing exosomes for targeted th.rapy: strategy and applic.tion

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Biomaterials Translational 2024年第1期5卷 46-58页

作者： Ren X. Xu R. Xu c. Su j. Organoid Researc. c.nter Institute of Translational Medicine Shanghai University Shanghai China National c.nter for Translational Medic.ne (Sh.ngh.i) Sh. Branc. Shanghai University Shanghai China Department of Mic.obial Path.genesis Yale University School of Medicine New Haven CT United States Department of Biomedic.l Engineering City University of Hong Kong Hong Kong Special Administrative Region China Department of Orth.pedic Xinhua Hospital Shanghai Jiao Tong University School of Medicine Shanghai China

Exosomes, nanosc.pic.extrac.llular vesic.es produc.d by c.lls, are pivotal in mediating intrac.llular c.mmunic.tion by transporting nuc.eic.ac.ds, proteins, lipids, and oth.r bioac.ive molec.les, th.reby influenc.ng ph.siologic.l and path.logic.l states. Th.ir endogenous origin and inh.rent diversity c.nfer distinc. advantages over synth.tic.veh.c.es like liposomes and nanopartic.es in diagnostic.and th.rapeutic.applic.tions. Despite th.ir potential, th. c.inic.l utility of exosomes is h.mpered by c.allenges suc. as limited storage stability, yield, purity, and targeting effic.enc.. Th.s review foc.ses on exosomes as targeted th.rapeutic.agents, examining th.ir biogenesis, c.assific.tion, isolation, and c.arac.erisation, wh.le also addressing th. c.rrent limitations in yield, purity, and targeting. We delve into th. literature to propose optimisation strategies th.t c.n enh.nc. th.ir th.rapeutic.effic.c. and ac.elerate th. translation of exosome-based th.rapies into c.inic.l prac.ic.. © 2024, c.inese Medic.l Multimedia Press c. Ltd. All righ.s reserved.

关键词： biomedic.l engineering exosomes modific.tion nanotec.nology targeted th.rapy

Study on th. dynamic.c.ntac. relationsh.p between layers under temperature gradients in c.TSⅢ ballastless trac.

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h.gh.speed Railway 2024年第3期2卷 133-142页

作者： Zh.o L. Zh.o G. Yang G. j.n h. Li c. Railway Engineering Researc. Institute China Academy of Railway Sciences Co. Ltd Beijing 100081 China c.ina State Railway Group c.. Ltd. Beijing 100844 China Sc.ool of Transportation Southeast University Nanjing 211189 China Sc.ool of Traffic.and Transportation Beijing Jiaotong University Beijing 100081 China

In areas with.large temperature differenc.s, th. uneven distribution of temperatures in th. c.TS III ballastless trac. slab due to daytime sunligh. c.n c.use warpage deformation, leading to periodic.rail irregularities th.t inc.ease th. wh.el-rail impac. of h.gh.speed veh.c.es and ac.elerate trac. struc.ure damage. Th.refore, it is nec.ssary to study th. dynamic.c.ntac. relationsh.p between th. c.mposite slab and th. base plate during veh.c.e running. Th. results of th. study sh.w th.t: 1) Under th. influenc. of temperature gradients, th. c.mposite slab tends to deform elliptic.lly. With.a positive temperature gradient, th. middle part of th. trac. slab bulges upward, c.using th. slab to be supported by its four c.rners. c.nversely, with.a negative temperature gradient, th. four c.rners of th. trac. slab bulge upward, resulting in th. slab being supported by its c.nter. 2) Temperature gradients c.n lead to separation between th. c.mposite slab and th. base plate, reduc.ng th. c.ntac. area between layers. During veh.c.e running, th. c.ntac. area between layers gradually inc.eases, but th. separation c.nnot be c.mpletely c.osed. 3) Th. temperature gradient signific.ntly affec.s th. vertic.l displac.ment of th. trac.. Th. vertic.l displac.ment in th. middle of th. slab inc.eases with.a positive temperature gradient. In c.ntrast, th. vertic.l displac.ment at th. ends of th. slab inc.eases with.a negative temperature gradient. 4) Th. stress of self-c.mpac.ing c.nc.ete at th. side position signific.ntly inc.eases under a positive temperature gradient, with.th. vertic.l stress inc.easing by 2.7 times wh.n th. temperature gradient inc.eases from 0 to 90 ℃·m−1. © 2024

关键词： Ballastless trac. h.gh.speed railway Interlayer c.ntac. Periodic.irregularities Temperature gradient

Investigation of h.0}R2 antagonists as a potential strategy to modulate bovine leukoc.tes

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j.urnal of Animal Sc.enc. and Biotec.nology 2024年第4期15卷 1567-1577页

作者： Laman K.Mamedova Kirby c.Krogstad Paiton O.Mc.onald Laxman Pokh.el Duy h.h.a Evan c.Titgemeyer Barry j.Bradford Department of Animal Sc.enc. Michigan State UniversityEast LansingMichigan 48824USA Department of Animal Sc.enc.s and Industry Kansas State UniversityManhattanKS 66506USA c.mparative Medic.ne and Integrative Biology East LansingMI 48824USA Department of c.emistry Kansas State UniversityManhattanKS 66506USA

Bac.ground Dairy c.ws experienc.ng ketosis after c.lving suffer greater disease inc.denc. and are at greater risk of leaving th. h.rd. In vitro administration of beta-h.droxybutyric.ac.d(Bh.A;th. primary blood ketone) h.s inh.bitory effec.s on th. func.ion of bovine leukoc.tes. Bh.A is a ligand of h.0}R2 and th. ac.ivation of th.se rec.ptors promotes an anti-inflammatory response wh.c. may be related with.immunosuppression observed in transition dairy c.ttle. Th. obj.c.ive of th.s study was to identify and test antagonists for h.0}R2 in bovine immune c.lls c.ltured with.*** We observed expression of h.0}R2 at th. protein level with.n lymph.c.tes, monoc.tes, and granuloc.tes. Th. proportion of c.lls expressing h.0}R2 tended to be greater in mid-lac.ation c.mpared to early lac.ation c.ws;th. inc.ease was a result of inc.eased proportion of T and B c.lls expressing h.0}R2. Stimulation of h.0}R2 with.niac.n or Bh.A promoted c.^(2+) mobilization in neutroph.ls and mononuc.ear c.lls. Mononuc.ear c.lls treated with.Bh.A h.d diminish.d intrac.llular c.^(2+) responses wh.n h.0}R2 was knoc.ed down by si RNA silenc.ng, indic.ting c.^(2+) mobilization was mediated by h.0}R2 signaling. Two c.ndidate antagonists for h.0}R2, synth.sized from niac.n(NA-1 and NA-5), were tested;monoc.tes and neutroph.ls pre-treated with.NA-1 and NA-5 h.d reduc.d c.^(2+) mobilization after inc.bation with.Bh.A. Furth.rmore, NA-5 but not NA-1 prevented Bh.A-assoc.ated reduc.ions in c.c.ic.*** We demonstrated th.t h.0}R2 is present on bovine leukoc.tes and h.s greater expression later in lac.ation. We c.nfirmed th.t Bh.A and niac.n derived h.0}R2 antagonists alter bovine leukoc.te ac.ivity. Our results demonstrate th.t both.Bh.A and niac.n affec. bovine leukoc.te c.^(2+) mobilization in a h.0}R2-dependent manner.

关键词： Flow c.tometry GPR109A h.74A Ketosis

A Study of th. TPS Based Beam-Matc.ing c.nc.pt for Medic.l Linear Ac.elerators at a Tertiary h.spital

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International j.urnal of Medic.l Ph.sic., c.inic.l Engineering and Radiation Onc.logy 2024年第1期13卷 16-25页

作者： Ntombela N. Leth.kuth.la Rovetto j. Nic.las Neth.adzi c. Lutendo Mpumelelo Nyath. Department of Radiation Onc.logy Steve Biko Academic Hospital Pretoria South Africa Department of Medic.l Ph.sic. University of Pretoria Pretoria South Africa Department of Medic.l Ph.sic. Sefako Makgatho Health Sciences University Ga-Rankuwa South Africa

Th. flexibility in radioth.rapy c.n be improved if patients c.n be moved between any one of th. department’s medic.l linear ac.elerators (LINAc.) with.ut th. need to c.ange anyth.ng in th. patient’s treatment plan. For th.s to be possible, th. dosimetric.c.arac.eristic. of th. various ac.elerators must be th. same, or nearly th. same. Th. purpose of th.s work is to desc.ibe furth.r and c.mpare measurements and parameters after th. initial vendor-rec.mmended beam matc.ing of th. five LINAc.. Deviations related to dose c.lc.lations and to beam matc.ed ac.elerators may c.mpromise treatment ac.urac.. Th. safest and most prac.ic.l way to ensure th.t all ac.elerators are with.n c.inic.l ac.eptable ac.urac. is to inc.ude TPS c.lc.lations in th. LINAc. matc.ing evaluation. Treatment planning system (TPS) was used to c.eate th.ee ph.tons plans with.different field sizes 3 × 3 c., 10 × 10 c. and 25 × 25 c. at a depth.of 4.5 c. in Perspex. c.lc.lated TPS plans were sent to Mosaiq to be delivered by five LINAc.. TPS plans were c.mpared with.five LINAc. measurements data using Gamma analyses of 2% and 2 mm. Th. results suggest th.t for four out of th. five LINAc., th.re was generally good agreement, less th.n a 2% deviation between th. planned dose distribution and th. measured dose distribution. h.wever, one spec.fic.LINAc.named “Asterix” exh.bited a deviation of 2.121% from th. planned dose. Th. results sh.w th.t all of th. LINAc.’ performanc. were with.n th. ac.eptable deviation and delivering radiation dose c.nsistently and ac.urately.

关键词： Radioth.rapy Beam-Matc.ing Linear Ac.elerator Dosimetry

Observability Analysis of Integrated Elec.ric.ty and h.ating Systems with.Th.rmal Quasi-dynamic. in Pipelines

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c.EE j.urnal of Power and Energy Systems 2024年第3期10卷 1145-1158页

作者： Zh.gang Li Wenj.an Zh.ng j.nbo Zh.o j.h.Zh.ng Q.h.Wu Sc.ool of Elec.ric.Power Engineering South China University of TechnologyGuangzhou 510641China Fuzh.u c.angle Distric. Power Supply c.mpany of State Grid Fuj.an Elec.ric.Power c.. Ltd.Fuzhou 350000China Department of Elec.ric.l and c.mputer Engineering University of ConnecticutStorrsCT 06269USA c.EE IEEE

Observability analysis(OA)is vital to obtaining th. available input measurements of state estimation(SE)in an integrated elec.ric.ty and h.ating system(IEh.).c.nsidering th. th.rmal quasi-dynamic. in pipelines,th. measurement equations in h.ating systems are dependent on th. estimated results,leading to an interdependenc. between OA and *** OA meth.ds require measurement equations be known exac.ly before SE is performed,and th.y are not applic.ble to *** bridge th.s gap,a sc.nario-based OA sc.eme for IEh.s is devised th.t yields reliable analysis results for a predefined set of time-delay sc.narios to c.pe with.th.s *** its c.re proc.dure,th. observable state identific.tion and observability restoration are formulated in terms of integer linear *** tests are c.nduc.ed to demonstrate th. validity and superiority of th. proposed formulation.

关键词： Integrated elec.ric.ty and h.ating system measurement observability analysis state estimation th.rmal quasi-dynamic.

Effic.ent guiding and foc.sing of intense laser pulse using periodic.th.n 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.h.ang K.j.ang c.N.Wu h.Peng P.c.h.n R.Li h.B.Zh.o c.T.Zh.u Sh.nzh.n Key Laboratory of Ultraintense Laser and Advanc.d Material Tec.nology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits h.ve been widely used in laser-plasma interac.ions as plasma optic.l c.mponents for generating h.gh.h.rmonic.ligh. and c.ntrolling laser-driven partic.e ***,we propose and demonstrate th.t periodic.th.n slits c.n be regarded as a new breed of optic.l elements for effic.ent foc.sing and guiding of intense laser *** fundamental ph.sic. of intense laser interac.ion with.th.n slits is studied,and it is revealed th.t relativistic.effec.s c.n lead to enh.nc.d laser foc.sing far beyond th. pure diffrac.ive foc.sing *** addition,th. interac.ion of an intense laser pulse with.periodic.th.n slits makes it feasible to ac.ieve multifold enh.nc.ment in both.laser intensity and energy transfer effic.enc. c.mpared with.c.nventional *** results provide a novel meth.d for manipulating ultra-intense laser pulses and sh.uld be of interest for many laser-based applic.tions.

关键词： laser pulse intense

A detailed c.mparison of th. c.mposition of(RE)-Ba-c.-O-Ag bulk superc.nduc.ors

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Superc.nduc.ivity 2024年第1期9卷 87-94页

作者： j.V.j.c.ngreve Y.Sh. A.R.Dennis h.Druiff N.c.Tutt D.A.c.rdwell j.h.Durrell Department of Engineering University of CambridgeCambridgeUK

Th. h.mogeneity of th. mic.ostruc.ure and c.mposition are c.itic.l in determining th. properties of rare earth.arium‐c.prate,single grain bulk superc.nduc.ors[(RE)Bc.].Th. magnitude of th. trapped magnetic.field ac.ieveable in th.se tec.nologic.lly important materials,in partic.lar,is influenc.d h.avily by th. size and distribution of(RE)_(2)Bac.O_(x)(RE‐211)flux pinning inc.usions in th. bulk mic.ostruc.ure,wh.reas th. size and distribution of silver agglomerates present with.n th. bulk superc.nduc.ing matrix c.rrelate direc.ly with.improved mec.anic.l *** c.reful engineering,th.se materials h.ve signific.nt potential for applic.tion in range of devic.s related to energy storage,medic.ne,elec.ro‐magnetic.mac.inery and mic.oelec.ronic.*** of(RE)Bc. bulk superc.nduc.ors typic.lly involves h.ating a powder c.mpac. above its peritec.ic.dec.mposition temperature followed by slow c.oling to fac.litate th. growth.of a single ***(RE)Bc. c.mposition h.s a different peritec.ic.temperature and growth.rate,wh.c.,th.refore,nec.ssitates different requirements in th. h.ating *** fabric.tion temperature and growth.rate,for example,may h.ve an effec. on th. RE‐211 and silver distribution,wh.c. may,in turn,affec. th. superc.nduc.ing properties of th. resulting single *** th.s work we c.mpare th. distributions of silver and RE‐211 in th. single grain mic.ostruc.ures of YBc.Ag,GdBc.‐Ag,EuBc.‐Ag and SmBc.‐Ag bulk superc.nduc.ors using optic.l mic.osc.py,sc.nning elec.ron mic.osc.py and energy dispersive X‐ray *** observe th.t th. distributions are very similar along both.th. a/b‐axis and c.axis of th.se *** suggests th.t fac.ors oth.r th.n th. maximum temperature used to ac.ieve peritec.ic.dec.mposition and th. rate of single grain growth.are partic.larly influential in determining th. properties of th. as‐proc.ssed samples in th. top seeded melt growth.*** observation demonstrates th.re is freedom to us

关键词： YBc.‐Ag GdBc.‐Ag SmBc.‐Ag EuBc.‐Ag c.mposition Bulk superc.nduc.or