49,414 research outputs found
The effect of non-linear quantum electrodynamics on relativistic transparency and laser absorption in ultra-relativistic plasmas
With the aid of large-scale three-dimensional QED-PIC simulations, we
describe a realistic experimental configuration to measure collective effects
that couple strong field quantum electrodynamics to plasma kinetics. For two
counter propagating lasers interacting with a foil at intensities exceeding
Wcm, a binary result occurs; when quantum effects are
included, a foil that classically would effectively transmit the laser pulse
becomes opaque. This is a dramatic change in plasma behavior, directly as a
consequence of the coupling of radiation reaction and pair production to plasma
dynamics
Influence of the charge carrier tunneling processes on the recombination dynamics in single lateral quantum dot molecules
We report on the charge carrier dynamics in single lateral quantum dot
molecules and the effect of an applied electric field on the molecular states.
Controllable electron tunneling manifests itself in a deviation from the
typical excitonic decay behavior which is strongly influenced by the tuning
electric field and inter-molecular Coulomb energies. A rate equation model is
developed to gain more insight into the charge transfer and tunneling
mechanisms. Non-resonant (phonon-mediated) electron tunneling which changes the
molecular exciton character from direct to indirect, and vice versa, is found
to be the dominant tunable decay mechanism of excitons besides radiative
recombination.Comment: 4 pages, 4 figure
Sporopollenin, a natural copolymer, is robust under high hydrostatic pressure
Lycopodium sporopollenin, a natural copolymer, shows exceptional stability under high hydrostatic pressures (10 GPa) as determined by in situ high pressure synchrotron source FTIR spectroscopy. This stability is evaluated in terms of the component compounds of the sporopollenin: p-coumaric acid, phloretic acid, ferulic acid, and palmitic and sebacic acids, which represent the additional n-acid and ndiacid components. This high stability is attributed to interactions between these components, rather than the exceptional stability of any one molecular component. We propose a biomimetic solution for the creation of polymer materials that can withstand high pressures for a multitude of uses in aeronautics, vascular autografts, ballistics and light-weight protective materials
Magnitude and Sign Correlations in Heartbeat Fluctuations
We propose an approach for analyzing signals with long-range correlations by
decomposing the signal increment series into magnitude and sign series and
analyzing their scaling properties. We show that signals with identical
long-range correlations can exhibit different time organization for the
magnitude and sign. We find that the magnitude series relates to the nonlinear
properties of the original time series, while the sign series relates to the
linear properties. We apply our approach to the heartbeat interval series and
find that the magnitude series is long-range correlated, while the sign series
is anticorrelated and that both magnitude and sign series may have clinical
applications.Comment: 4 pages,late
Mesons and Nucleons in Soft-Wall AdS/QCD with Constrained Infrared Background
The purpose of this paper is to further study the soft-wall AdS/QCD model
with constrained IR background. By including a quartic bulk scalar potential we
study various meson and nucleon spectra. This model naturally realizes the
asymptotical linearity of these mass spectra simultaneously, together with
correctly pattern of explicit and dynamical chiral symmetry breaking. The
agreement between the theoretical calculations and the experimental data is
good.Comment: 17 pages,5 table
Lower bounds on the blow-up rate of the axisymmetric Navier-Stokes equations II
Consider axisymmetric strong solutions of the incompressible Navier-Stokes
equations in with non-trivial swirl. Let denote the axis of symmetry
and measure the distance to the z-axis. Suppose the solution satisfies
either or, for some \e > 0, for and
allowed to be large. We prove that is regular at time zero.Comment: More explanations and a new appendi
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