109,754 research outputs found
Chiral geometry and rotational structure for Cs in the projected shell model
The projected shell model with configuration mixing for nuclear chirality is
developed and applied to the observed rotational bands in the chiral nucleus
Cs. For the chiral bands, the energy spectra and electromagnetic
transition probabilities are well reproduced. The chiral geometry illustrated
in the and the is confirmed to be stable against the
configuration mixing. The other rotational bands are also described in the same
framework
Gibbsian Hypothesis in Turbulence
We show that Kolmogorov multipliers in turbulence cannot be statistically
independent of others at adjacent scales (or even a finite range apart) by
numerical simulation of a shell model and by theory. As the simplest
generalization of independent distributions, we suppose that the steady-state
statistics of multipliers in the shell model are given by a
translation-invariant Gibbs measure with a short-range potential, when
expressed in terms of suitable ``spin'' variables: real-valued spins that are
logarithms of multipliers and XY-spins defined by local dynamical phases.
Numerical evidence is presented in favor of the hypothesis for the shell model,
in particular novel scaling laws and derivative relations predicted by the
existence of a thermodynamic limit. The Gibbs measure appears to be in a
high-temperature, unique-phase regime with ``paramagnetic'' spin order.Comment: 19 pages, 9 figures, greatly expanded content, accepted to appear in
J. Stat. Phy
Low-lying states in even Gd isotopes studied with five-dimensional collective Hamiltonian based on covariant density functional theory
Five-dimensional collective Hamiltonian based on the covariant density
functional theory has been applied to study the the low-lying states of
even-even Gd isotopes. The shape evolution from Gd to
Gd is presented. The experimental energy spectra and intraband
transition probabilities for the Gd isotopes are reproduced by the
present calculations. The relative ratios in present calculations are
also compared with the available interacting boson model results and
experimental data. It is found that the occupations of neutron
orbital result in the well-deformed prolate shape, and are essential for Gd
isotopes.Comment: 11pages, 10figure
Stability Of contact discontinuity for steady Euler System in infinite duct
In this paper, we prove structural stability of contact discontinuities for
full Euler system
Resonant Interactions in Rotating Homogeneous Three-dimensional Turbulence
Direct numerical simulations of three-dimensional (3D) homogeneous turbulence
under rapid rigid rotation are conducted to examine the predictions of resonant
wave theory for both small Rossby number and large Reynolds number. The
simulation results reveal that there is a clear inverse energy cascade to the
large scales, as predicted by 2D Navier-Stokes equations for resonant
interactions of slow modes. As the rotation rate increases, the
vertically-averaged horizontal velocity field from 3D Navier-Stokes converges
to the velocity field from 2D Navier-Stokes, as measured by the energy in their
difference field. Likewise, the vertically-averaged vertical velocity from 3D
Navier-Stokes converges to a solution of the 2D passive scalar equation. The
energy flux directly into small wave numbers in the plane from
non-resonant interactions decreases, while fast-mode energy concentrates closer
to that plane. The simulations are consistent with an increasingly dominant
role of resonant triads for more rapid rotation
Transonic Shocks In Multidimensional Divergent Nozzles
We establish existence, uniqueness and stability of transonic shocks for
steady compressible non-isentropic potential flow system in a multidimensional
divergent nozzle with an arbitrary smooth cross-section, for a prescribed exit
pressure. The proof is based on solving a free boundary problem for a system of
partial differential equations consisting of an elliptic equation and a
transport equation. In the process, we obtain unique solvability for a class of
transport equations with velocity fields of weak regularity(non-Lipschitz), an
infinite dimensional weak implicit mapping theorem which does not require
continuous Frechet differentiability, and regularity theory for a class of
elliptic partial differential equations with discontinuous oblique boundary
conditions.Comment: 54 page
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