Search results for "Localized"

showing 10 items of 297 documents

SVEP and local spectral radius formula for unbounded operators

2014

In this paper we study the localized single valued extension property for an unbounded operator T. Moreover, we provide sufficient conditions for which the formula of the local spectral radius holds for these operators.

Spectral radiusSettore MAT/05 - Analisi MatematicaGeneral MathematicsMathematical analysisLocalized SVEP local spectral radius formulaMathematics
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Spin Density Maps in the Triplet Ground State of [Cu2(t-Bupy)4(N3)2](ClO4)2 (t-Bupy = p-tert-butylpyridine):  A Polarized Neutron Diffraction Study

1998

This paper is devoted to the determination of the spin distribution in the spin triplet ground state of [Cu-2(t-Bupy)(4)(N-3)(2)](ClO4)(2), With t-Bupy = p-tert-butylpyridine. The crystal structure, previously solved at room temperature from X-ray diffraction, has been redetermined at 18 K from unpolarized neutron diffraction. The structure consists of binuclear cations in which Cu2+ ions are doubly bridged by azido groups in the 1,1-fashion, and noncoordinated perchlorate anions. The experimental spin distribution has been determined from polarized neutron diffraction (PND) at 1.6 K under 50 kOe. The spin populations have been found to be strongly positive on the Cu2+ ions, weakly positive…

Spin polarizationChemistryNeutron diffractionBridging ligandGeneral ChemistryCrystal structureBiochemistryCatalysisIonDelocalized electronCrystallographyColloid and Surface ChemistryAtomic orbitalGround stateJournal of the American Chemical Society
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Interfaces in the confined Ising system with competing surface fields

2005

Abstract When a magnetic Ising film is confined in a L × M geometry ( L ⪡ M ) short-range competing magnetic fields ( h 1 ) are applied at opposite walls along the M -direction, a (weakly rounded) localization–delocalization transition of the interface between domains of different orientation that runs parallel to walls can be observed. This transition is the precursor of a wetting phase transition that occurs in the limit of infinite film thickness ( L → ∞ ) at the critical curve T w ( h 1 ) . For T T w ( h 1 ) ( T > T w ( h 1 ) ) such an interface is bound to (unbound from) the walls, while right at T w ( h 1 ) the interface is freely fluctuating around the center of the film. We present …

Statistics and ProbabilityPhysicsCapillary waveMagnetizationDelocalized electronPhase transitionCondensed matter physicsPosition (vector)Monte Carlo methodIsing modelCondensed Matter PhysicsMagnetic fieldPhysica A: Statistical Mechanics and its Applications
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On delocalization of eigenvectors of random non-Hermitian matrices

2019

We study delocalization of null vectors and eigenvectors of random matrices with i.i.d entries. Let $A$ be an $n\times n$ random matrix with i.i.d real subgaussian entries of zero mean and unit variance. We show that with probability at least $1-e^{-\log^{2} n}$ $$ \min\limits_{I\subset[n],\,|I|= m}\|{\bf v}_I\| \geq \frac{m^{3/2}}{n^{3/2}\log^Cn}\|{\bf v}\| $$ for any real eigenvector ${\bf v}$ and any $m\in[\log^C n,n]$, where ${\bf v}_I$ denotes the restriction of ${\bf v}$ to $I$. Further, when the entries of $A$ are complex, with i.i.d real and imaginary parts, we show that with probability at least $1-e^{-\log^{2} n}$ all eigenvectors of $A$ are delocalized in the sense that $$ \min\l…

Statistics and ProbabilityZero mean010102 general mathematicsNull (mathematics)Probability (math.PR)01 natural sciencesHermitian matrixCombinatorics010104 statistics & probabilityDelocalized electronFOS: Mathematics0101 mathematicsStatistics Probability and UncertaintyRandom matrixUnit (ring theory)Mathematics - ProbabilityAnalysisEigenvalues and eigenvectorsMathematicsProbability Theory and Related Fields
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Polymorphism in Cs[AgZn(NCS)4].

2002

The title compound, caesium silver zinc tetrathiocyanate, crystallizes in two polymorphic forms, in space groups P2(1)/n and C2/c. Both structures form a continuous three-dimensional network. The structure in C2/c contains a delocalized Ag atom in a binuclear-like anion, where two [Ag(NCS)(4)] units (delocalized Ag as an average) share two common NCS(-) ligands.

StereochemistrySpace groupchemistry.chemical_elementGeneral MedicineCrystal structureZincMolecular biologyGeneral Biochemistry Genetics and Molecular BiologyIonCrystallographyDelocalized electronchemistryPolymorphism (materials science)CaesiumMoleculeActa crystallographica. Section C, Crystal structure communications
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Crystal structure of 4-[(adamantan-1-yl)amino]­naphthalene-1,2-dione

2019

The title compound, an example of a stable 1,2-naphtho­quinone, illustrates steric buttressing of the adamantanyl group.

Steric effectscrystal structureAdamantaneintra­molecular hydrogen bondingadamantanenaphthoquinoneAdamantaneCrystal structureN— HO hydrogen bonding010402 general chemistry010403 inorganic & nuclear chemistry01 natural sciencesResearch CommunicationsCrystallcsh:ChemistryDelocalized electronchemistry.chemical_compoundNaphthoquinoneGroup (periodic table)General Materials ScienceNaphthaleneintramolecular hydrogen bondingCrystal structurenaphtho­quinone548.81 Cristalografía estructuralIntramolecular hydrogen bondingGeneral ChemistryCondensed Matter PhysicsNaphthoquinone0104 chemical sciencesCrystallographychemistrylcsh:QD1-999N—H...O hydrogen bondingN—H⋯O hydrogen bondingActa Crystallographica Section E: Crystallographic Communications
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Ab initio Calculations of Bulk and (001) Surface F-centers in ABO3 Perovskites

2021

We analyzed systematic trends in BaTiO 3, SrTiO 3 , PbZrO 3 and SrZrO 3 bulk as well as very rarely performed (001) surface F-center ab initio calculations. The nearest neighbor atomic displacements around the bulk F-center in the ABO 3 perovskites are considerably smaller than the relevant neighbor atomic displacements around the (001) surface $F$ -centers. The $F$ -center electrons are more delocalized for the ABO 3 perovskite (001) surface $F$ -center than for the bulk $F$ -center. Our calculated formation energy differences between the BaTiO 3 , SrTiO 3 , PbZrO 3 and SrZrO 3 bulk and its (001) surface $F$ -centers triggers the $F$ -center segregation from the bulk crystal towards the AB…

Surface (mathematics)Delocalized electronMaterials scienceCondensed matter physicsAb initio quantum chemistry methodsElectronk-nearest neighbors algorithmPerovskite (structure)Bulk crystal2021 IEEE 12th International Conference on Electronics and Information Technologies (ELIT)
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Phase-bistable patterns and cavity solitons induced by spatially periodic injection into vertical-cavity surface-emitting lasers

2014

Spatial rocking is a kind of resonant forcing able to convert a self-oscillatory system into a phase-bistable, pattern forming system, whereby the phase of the spatially averaged oscillation field locks to one of two values differing by $\ensuremath{\pi}$. We propose the spatial rocking in an experimentally relevant system---the vertical-cavity surface-emitting laser (VCSEL)---and demonstrate its feasibility through analytical and numerical tools applied to a VCSEL model. We show phase bistability, spatial patterns, such as roll patterns, domain walls, and phase (dark-ring) solitons, which could be useful for optical information storage and processing purposes.

Surface (mathematics)PhysicsField (physics)Bistabilitybusiness.industryOscillationPhase (waves)Physics::OpticsÒpticaLaserSEMICONDUCTOR-LASERS; OPTICAL-SYSTEMSAtomic and Molecular Physics and OpticsVertical-cavity surface-emitting laserlaw.inventionOpticslawDYNAMICS; OSCILLATORS; PIXELSSpatial ecologySWIFT-HOHENBERG EQUATION; LOCALIZED STRUCTURES;businessPhysical Review A
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Overview of the JET results in support to ITER

2017

The 2014–2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to ITER is supported by first principle modelling. ITER relevant disruption experiments and first principle modelling are reported with a set of three disruption mitigation valves mimicking the ITER setup. Insights of the L–H power threshold in Deuterium and Hydrogen are given, stressing the importance of the magnetic configurations and the recent m…

Technologyfusion:Física [Ciências exactas e naturais]TokamakNuclear engineeringDIAGNOSTICS01 natural sciencesILW010305 fluids & plasmaslaw.inventionIlw[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]PlasmaH-Mode PlasmaslawITERDisruption PredictionCOLLISIONALITYEDGE LOCALIZED MODESDiagnosticsOperationfusion; ITER; JET; plasma; Nuclear and High Energy Physics; Condensed Matter PhysicsPhysicsJet (fluid)JET plasma fusion ITERDivertorSettore FIS/01 - Fisica SperimentaleCondensed Matter PhysicsFusion Plasma and Space PhysicsDENSITY PEAKINGCarbon WallH-MODE PLASMAS[ SPI.MECA.MEFL ] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]Density PeakingNuclear and High Energy PhysicsNeutron transportFacing ComponentsCollisionality114 Physical sciencesFísica FísicaNuclear physics:Physical sciences [Natural sciences]Fusion plasma och rymdfysikPedestal0103 physical sciencesNuclear fusionddc:530Neutron010306 general physicsFusionplasmaPhysics Physical sciencesNuclear and High Energy PhysicEdge Localized ModesQC717:Física [Àrees temàtiques de la UPC]Reactors de fusióFísicaFACING COMPONENTSFusion reactorsJetJETCARBON WALLDISRUPTION PREDICTIONOPERATIONddc:600Collisionality
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Surface plasmon interference fringes in back-reflection

2010

We report the experimental observation of surface plasmon polariton (SPP) interference fringes with near-unity visibility and half-wavelength periodicity obtained in back reflection on a Bragg mirror. The presented method based on leakage radiation microscopy (LRM) represents an alternative solution to optical near-field analysis and opens new ways for the quantitative analysis of SPP fringes. With LRM we investigate various SPP interference patterns and analyze the high reflectivity of Bragg mirror in comparison with theoretical models.

Theoretical modelsFOS: Physical sciencesGeneral Physics and AstronomyPhysics::Optics02 engineering and technology01 natural sciencesOpticsInterference (communication)0103 physical sciencesMicroscopy010306 general physicsPhysicsCondensed Matter::Quantum Gases[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]business.industrySurface plasmon021001 nanoscience & nanotechnologyDistributed Bragg reflectorSurface plasmon polariton[ PHYS.PHYS.PHYS-AO-PH ] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]Reflection (physics)Optoelectronics0210 nano-technologybusinessPhysics - OpticsOptics (physics.optics)Localized surface plasmon
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