Search results for "MEG"

showing 10 items of 1641 documents

Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture II: Intermediate Scattering Function and Dynamic Susceptibility

1995

We have performed a molecular dynamics computer simulation of a supercooled binary Lennard-Jones system in order to compare the dynamical behavior of this system with the predictions of the idealized version of mode-coupling theory (MCT). By scaling the time $t$ by the temperature dependent $\alpha$-relaxation time $\tau(T)$, we find that in the $\alpha$-relaxation regime $F(q,t)$ and $F_s(q,t)$, the coherent and incoherent intermediate scattering functions, for different temperatures each follows a $q$-dependent master curve as a function of scaled time. We show that during the early part of the $\alpha$-relaxation, which is equivalent to the late part of the $\beta$-relaxation, these mast…

PhysicsCondensed matter physicsScatteringCondensed Matter (cond-mat)FOS: Physical sciencesCondensed MatterFick's laws of diffusionOmegaPower lawCondensed Matter::Disordered Systems and Neural NetworksUniversality (dynamical systems)ExponentScalingCritical exponentMathematical physics
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Nanoscale inhomogeneity of the Schottky barrier and resistivity inMoS2multilayers

2015

Conductive atomic force microscopy (CAFM) is employed to investigate the current injection from a nanometric contact (a Pt coated tip) to the surface of ${\text{MoS}}_{2}$ thin films. The analysis of local current-voltage characteristics on a large array of tip positions provides high spatial resolution information on the lateral homogeneity of the $\mathrm{tip}/{\text{MoS}}_{2}$ Schottky barrier ${\mathrm{\ensuremath{\Phi}}}_{B}$ and ideality factor $n$, and on the local resistivity ${\ensuremath{\rho}}_{\text{loc}}$ of the ${\text{MoS}}_{2}$ region under the tip. Here, ${\mathrm{\ensuremath{\Phi}}}_{B}=300\ifmmode\pm\else\textpm\fi{}24\phantom{\rule{0.28em}{0ex}}\text{meV}, n=1.60\ifmmode…

PhysicsCondensed matter physicsSchottky barrierSettore FIS/01 - Fisica SperimentaleCondensed Matter PhysicCoated tipCondensed Matter PhysicsOmegaElectronic Optical and Magnetic MaterialsElectrical resistivity and conductivityVacancy defectHigh spatial resolutionMoS2Schottky barrierNanoscopic scaleTip positionPhysical Review B
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Direct excitation of the “dark”b3Πstate predicted by deperturbation analysis of theA1Σ+−b3Πcomplex in KCs

2010

The diode-laser-induced fluorescence spectra $b {}^{3}{\ensuremath{\Pi}}_{\ensuremath{\Omega}=0}^{+}\ensuremath{\rightarrow}{X}^{ 1}{\ensuremath{\Sigma}}^{+}$ originated from the rovibronic levels of the ``dark'' triplet $b {}^{3}{\ensuremath{\Pi}}_{\ensuremath{\Omega}=0}^{+}$ state of KCs dimers were recorded with a Fourier transform spectrometer with a resolution of 0.03 cm${}^{\ensuremath{-}1}$. Term values of 30 rovibronic levels $({v}_{b0}^{*}\ensuremath{\in}[14,18];{J}^{\ensuremath{'}}\ensuremath{\in}[47,134])$ below the minimum of perturbing $A {}^{1}{\ensuremath{\Sigma}}^{+}$ state were determined with 0.003--0.01 cm${}^{\ensuremath{-}1}$ uncertainty. The optimal excitation and dete…

PhysicsCrystallographyDirect excitationNuclear magnetic resonanceParticle propertiesFourier transform spectrometersState (functional analysis)Singlet stateOmegaFluorescence spectraAtomic and Molecular Physics and OpticsSpin-½Physical Review A
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Experimental approach to transverse wave-number selection in cavity nonlinear optics

2004

Spontaneous transverse pattern formation is experimentally studied in a ${\text{BaTiO}}_{3}$ photorefractive oscillator under degenerate four-wave mixing conditions. A near self-imaging resonator of high Fresnel number and quasi-one-dimensional in the transverse plane is used. A fine control technique of the cavity detuning, $\ensuremath{\Omega}$, is described. It allows a precise study of the relation of $\ensuremath{\Omega}$ with the transverse wave number ${k}_{\ensuremath{\perp}}$ of the roll patterns selected by the system. The law ${k}_{\ensuremath{\perp}}^{2}=\ensuremath{-}\ensuremath{\Omega}∕a$ is verified, which evidences that wave-number selection is mainly dictated by the cavity …

PhysicsDiffractionTransverse planeQuantum mechanicsDomain (ring theory)Degenerate energy levelsFresnel numberNonlinear opticsBifurcation diagramOmegaAtomic and Molecular Physics and OpticsPhysical Review A
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Spectroscopic data, spin-orbit functions, and revised analysis of strong perturbative interactions for theA 1Σ+andb 3Πstates of RbCs

2010

The current interest in producing ultracold RbCs molecules by optical excitation from weakly bound Feshbach resonances and stimulated decay to the absolute ground state requires detailed analyses of the intermediate excited states. In this study, we present two sets of experimental Fourier-transform spectroscopic data of the $A{ }^{1}{\ensuremath{\Sigma}}^{+}$-$b{ }^{3}\ensuremath{\Pi}$ complex. The $A$-$b$ mixed vibrational levels are the most likely candidates to be intermediates in the molecular formation. The more recent and more accurate data set is from mixed $A$-$b\ensuremath{\rightarrow}X$ transitions, while the second is derived in large part from $(4){ }^{1}{\ensuremath{\Sigma}}^{…

PhysicsExcited stateResonanceAtomic physicsGround stateCoupling (probability)Spin (physics)OmegaHyperfine structureAtomic and Molecular Physics and OpticsEnergy (signal processing)Physical Review A
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The Møller Polarimeter for MAMI

1991

The polarization of high-energy electrons can conveniently be measured by means of Moller scattering from polarized electrons in a magnetized ferromagnetic target. This process exhibits in the limit of high energies (E ≥ 100 MeV) still relatively large, energy independent and well known analysator strengths. Furthermore, the laboratory cross section in the kinematical range suitable for polarimeter applications is large $$ \frac{{d\sigma }}{{d\Omega }}({\Theta _{cm}} = 90^\circ ) = Z \cdot 0.18{\text{ }}barn/sr$$ and energy-independent.

PhysicsFerromagnetismPolarimeterElectronMøller scatteringAtomic physicsPolarization (waves)Omega
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Friedel Oscillations in Relativistic Nuclear Matter

1994

We calculate the low-momentum N-N effective potential obtained in the OBE approximation, inside a nuclear plasma at finite temperature, as described by the relativistic $ \sigma $-$ \omega $ model. We analyze the screening effects on the attractive part of the potential in the intermediate range as density or temperature increase. In the long range the potential shows Friedel-like oscillations instead of the usual exponential damping. These oscillations arise from the sharp edge of the Fermi surface and should be encountered in any realistic model of nuclear matter.

PhysicsFriedel oscillationsRange (particle radiation)Sigma modelNuclear TheoryNuclear TheoryGeneral Physics and AstronomyFOS: Physical sciencesFermi surfacePlasmaNuclear matterOmegaExponential functionNuclear Theory (nucl-th)Quantum electrodynamicsFísica nuclear
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Unsteady turbulence in plane channel flow

2011

Abstract Direct numerical simulations were conducted for oscillating flow with zero time mean (reciprocating flow) in a plane channel subject to a harmonic forcing term of varying amplitude and frequency. The results confirmed the existence of four flow regimes (laminar, “disturbed laminar”, intermittently turbulent, and fully turbulent) depending on the above parameters. The flow behaviour was found to depend on the complex interplay of mean and turbulence quantities, as described by the closed loop formed by the streamwise Reynolds-averaged momentum equation in conjunction with the exact transport equations for the turbulent (Reynolds) stresses. A crucial role in this loop appeared to be …

PhysicsGeneral Computer ScienceTurbulenceChézy formulaK-epsilon turbulence modelUnsteady turbulence Channel flow Direct Numerical Simulation Turbulence BudgetGeneral EngineeringTurbulence modelingLaminar flowK-omega turbulence modelMechanicsOpen-channel flowPhysics::Fluid DynamicsClassical mechanicsTurbulence kinetic energySettore ING-IND/19 - Impianti NucleariComputers & Fluids
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Measurement of the form factors in the decayD+→ωe+νeand search for the decayD+→ϕe+νe

2015

Using 2.92 fb(-1) of electron-positron annihilation data collected at a center-of-mass energy of root s = 3.773 GeV with the BESIII detector, we present an improved measurement of the branching fra ...

PhysicsHadronic decayNuclear and High Energy PhysicsParticle physicsAnnihilationMeson010308 nuclear & particles physicsBranching fractionElectron–positron annihilation01 natural sciencesOmegaNuclear physics0103 physical sciencesHigh Energy Physics::Experiment010306 general physicsPhysical Review D
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Parabolic equations with natural growth approximated by nonlocal equations

2017

In this paper we study several aspects related with solutions of nonlocal problems whose prototype is $$ u_t =\displaystyle \int_{\mathbb{R}^N} J(x-y) \big( u(y,t) -u(x,t) \big) \mathcal G\big( u(y,t) -u(x,t) \big) dy \qquad \mbox{ in } \, \Omega \times (0,T)\,, $$ being $ u (x,t)=0 \mbox{ in } (\mathbb{R}^N\setminus \Omega )\times (0,T)\,$ and $ u(x,0)=u_0 (x) \mbox{ in } \Omega$. We take, as the most important instance, $\mathcal G (s) \sim 1+ \frac{\mu}{2} \frac{s}{1+\mu^2 s^2 }$ with $\mu\in \mathbb{R}$ as well as $u_0 \in L^1 (\Omega)$, $J$ is a smooth symmetric function with compact support and $\Omega$ is either a bounded smooth subset of $\mathbb{R}^N$, with nonlocal Dirichlet bound…

PhysicsKernel (set theory)Applied MathematicsGeneral Mathematics010102 general mathematicsMathematics::Analysis of PDEs01 natural sciencesParabolic partial differential equationOmega010101 applied mathematicsSymmetric functionCombinatoricssymbols.namesakeMathematics - Analysis of PDEsMathematics - Analysis of PDEs; Mathematics - Analysis of PDEsBounded functionDirichlet boundary conditionsymbolsFOS: MathematicsUniqueness0101 mathematicsAnalysis of PDEs (math.AP)
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