54,554 research outputs found
Quakes in Solid Quark Stars
A starquake mechanism for pulsar glitches is developed in the solid quark
star model. It is found that the general glitch natures (i.e., the glitch
amplitudes and the time intervals) could be reproduced if solid quark matter,
with high baryon density but low temperature, has properties of shear modulus
\mu = 10^{30~34} erg/cm^3 and critical stress \sigma_c = 10^{18~24} erg/cm^3.
The post-glitch behavior may represent a kind of damped oscillations.Comment: 11 pages, 4 figures (but Fig.3 is lost), a complete version can be
obtained by http://vega.bac.pku.edu.cn/~rxxu/publications/index_P.htm, a new
version to be published on Astroparticle Physic
Spin Dependence of Interfacial Reflection Phase Shift at Cu/Co Interface
The spin dependent reflection at the interface is the key element to
understand the spin transport. By completely solving the scattering problem
based on first principles method, we obtained the spin resolved reflectivity
spectra. The comparison of our theoretical results with experiment is good in a
large energy scale from Fermi level to energy above vacuum level. It is found
that interfacial distortion is crucial for understanding the spin dependence of
the phase gain at the CuCo interface. Near the Fermi level, image state
plays an important role to the phase accumulation in the copper film.Comment: 6 papges, 3 figures, accepted by Physical Review
Spectral Energy Distributions of M81 Globular Clusters in BATC Multicolor Survey
In this paper, we give the spectral energy distributions of 42 M81 globular
clusters in 13 intermediate-band filters from 4000 to 10000 A, using the CCD
images of M81 observed as part of the BATC multicolor survey of the Sky. The
BATC multicolor filter system is specifically designed to exclude most of the
bright and variable night-sky emission lines including the OH forest. Hence, it
can present accurate SEDs of the observed objects. These spectral energy
distributions are low-resolution spectra, and can reflect the stellar
populations of the globular clusters. This paper confirms the conclusions of
Schroder et al. that, M81 contains clusters as young as a few Gyrs, which also
were observed in both M31 and M33Comment: Accepted for Publication in PASP, 10 pages, 3 figure
General methods for designing single-mode planar photonic crystal waveguides in hexagonal lattice structures
We systematically investigate and compare general methods of
designing single mode photonic crystal waveguides in a two-dimensional hexagonal lattice of air holes in a dielectric material. We apply the rather general methods to dielectric-core hexagonal lattice photonic crystals since they have not been widely explored before. We show that it is possible to obtain single mode guiding in a limited portion of the photonic bandgap of hexagonal lattice structures. We also compare the potentials of different photonic crystal lattices for designing single-mode waveguides and conclude that triangular lattice structures are the best choice
Facilitated diffusion of DNA-binding proteins
The diffusion-controlled limit of reaction times for site-specific
DNA-binding proteins is derived from first principles. We follow the generally
accepted concept that a protein propagates via two competitive modes, a
three-dimensional diffusion in space and a one-dimensional sliding along the
DNA. However, our theoretical treatment of the problem is new. The accuracy of
our analytical model is verified by numerical simulations. The results confirm
that the unspecific binding of protein to DNA, combined with sliding, is
capable to reduce the reaction times significantly.Comment: 4 pages, 2 figures Nov 22 2005 - accepted for PR
Properties of weighted complex networks
We study two kinds of weighted networks, weighted small-world (WSW) and
weighted scale-free (WSF). The weight of a link between nodes and
in the network is defined as the product of endpoint node degrees; that is
. In contrast to adding weights to links during
networks being constructed, we only consider weights depending on the ``
popularity\rq\rq of the nodes represented by their connectivity. It was found
that the both weighted networks have broad distributions on characterization
the link weight, vertex strength, and average shortest path length.
Furthermore, as a survey of the model, the epidemic spreading process in both
weighted networks was studied based on the standard \emph{susceptible-infected}
(SI) model. The spreading velocity reaches a peak very quickly after the
infection outbreaks and an exponential decay was found in the long time
propagation.Comment: 14 pages, 5 figure
Doubly Heavy Baryon Production at A High Luminosity Collider
Within the framework of nonrelativistic QCD, we make a detailed discussion on
the doubly heavy baryon production through the annihilation channel,
, at a high luminosity collider. Here
stands for the heavy or quark. In addition to the
channel through the usually considered diquark state
, contributions from the channels through
other same important diquark states such as have
also been discussed. Uncertainties for the total cross sections are predicted
by taking GeV and GeV. At a super
-factory running around the mass and with a high luminosity up to
, we estimate
that about events,
events and events can be
generated in one operation year. Such a -factory, thus, will provide a good
platform for studying the doubly heavy baryons in comparable to the CERN large
hadronic collider.Comment: 9 pages, 4 figures. To be published in Phys.Rev.
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