63,351 research outputs found
A New Kind of Uniformly Accelerated Reference Frames
A new kind of uniformly accelerated reference frames with a line-element
different from the M{\o}ller and Rindler ones is presented, in which every
observer at consts. has the same constant acceleration. The laws of
mechanics are checked in the new kind of frames. Its thermal property is
studied. The comparison with the M{\o}ller and Rindler uniform accelerated
reference frames is also made.Comment: 10 pages, 2 figures. to appear in Int. J. Mod. Phys.
Intrinsic Percolative Superconductivity in Heavily Overdoped High Temperature Superconductors
Magnetic measurements on heavily overdoped ,
, and single crystals reveal
a new type magnetization hysteresis loops characterized by the vanishing of
usual central peak near zero field. Since this effect has been observed in
various systems with very different structural details, it reflects probably a
generic behavior for all high temperature superconductors. This easy
penetration of magnetic flux can be understood in the picture of percolative
superconductivity due to the inhomogeneous electronic state in heavily
overdoped regime.Comment: 4 pages, 5 figure
Thermal rectification in asymmetric U-shaped graphene flakes
In this paper, we study the thermal rectification in asymmetric U-shaped
graphene flakes by using nonequilibrium molecular dynamics simulations. The
graphene flakes are composed by a beam and two arms. It is found that the heat
flux runs preferentially from the wide arm to the narrow arm which indicates a
strong rectification effect. The dependence of the rectification ratio upon the
heat flux, the length and the width of the beam, the length and width of the
two arms are studied. The result suggests a possible route to manage heat
dissipation in U-shaped graphene based nanoelectronic devices.Comment: 3 pages, 4 figure
Binomial coefficients, Catalan numbers and Lucas quotients
Let be an odd prime and let be integers with and . In this paper we determine
mod for ; for example,
where is the Jacobi symbol, and is the Lucas
sequence given by , and for
. As an application, we determine modulo for any integer , where denotes the
Catalan number . We also pose some related conjectures.Comment: 24 pages. Correct few typo
New parametrization for the nuclear covariant energy density functional with point-coupling interaction
A new parametrization PC-PK1 for the nuclear covariant energy density
functional with nonlinear point-coupling interaction is proposed by fitting to
observables for 60 selected spherical nuclei, including the binding energies,
charge radii and empirical pairing gaps. The success of PC-PK1 is illustrated
in its description for infinite nuclear matter and finite nuclei including the
ground-state and low-lying excited states. Particularly, PC-PK1 improves the
description for isospin dependence of binding energy along either the isotopic
or the isotonic chains, which makes it more reliable for application in exotic
nuclei. The predictive power of PC-PK1 is also illustrated for the nuclear
low-lying excitation states in a five-dimensional collective Hamiltonian in
which the parameters are determined by constrained calculations for triaxial
shapes.Comment: 32 pages, 12 figures, 4 tables, accepted by Phys. Rev.
Discussion on Event Horizon and Quantum Ergosphere of Evaporating Black Holes in a Tunnelling Framework
In this paper, with the Parikh-Wilczek tunnelling framework the positions of
the event horizon of the Vaidya black hole and the Vaidya-Bonner black hole are
calculated respectively. We find that the event horizon and the apparent
horizon of these two black holes correspond respectively to the two turning
points of the Hawking radiation tunnelling barrier. That is, the quantum
ergosphere coincides with the tunnelling barrier. Our calculation also implies
that the Hawking radiation comes from the apparent horizon.Comment: 8 page
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