14,833 research outputs found
Exact solution of the trigonometric SU(3) spin chain with generic off-diagonal boundary reflections
The nested off-diagonal Bethe ansatz is generalized to study the quantum spin
chain associated with the R-matrix and generic integrable
non-diagonal boundary conditions. By using the fusion technique, certain closed
operator identities among the fused transfer matrices at the inhomogeneous
points are derived. The corresponding asymptotic behaviors of the transfer
matrices and their values at some special points are given in detail. Based on
the functional analysis, a nested inhomogeneous T-Q relations and Bethe ansatz
equations of the system are obtained. These results can be naturally
generalized to cases related to the algebra.Comment: published version, 27 pages, 1 table, 1 figur
Antiretroviral Therapy Initiation Following Policy Changes: Observations From China.
China's HIV/AIDS treatment policies have been evolving over the preceding decade. This study describes patterns of antiretroviral therapy (ART) initiation for a sample of people living with HIV/AIDS (PLHIV) in rural Anhui, China, where most PLHIV were infected via paid plasma donation during the 1990s. A total of 481 PLHIV who were receiving ART were included in our analyses. Times between HIV diagnosis and the initiation of ART were examined relative to the time points when major ART-related policies changed in China. More than half (53%) of PLHIV who had been diagnosed by 2003 received ART within 6 months, whereas 93% of PLHIV who had been diagnosed in 2010 or later received ART within 6 months. The study results provide additional support that the "Four Frees and One Care" policy in 2003 and the relaxation of ART eligibility in 2010 have facilitated the initiation of treatment for PLHIV in China
Statistical Properties of Multiple Optical Emission Components in Gamma-Ray Bursts and Implications
Well-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are complied
from the literature. Multiple optical emission components are extracted with
power-law function fits to these lightcurves. We present a systematical
analysis for statistical properties and their relations to prompt gamma-ray
emission and X-ray afterglow for each component. We show that peak luminosity
in the prompt and late flares are correlated and the evolution of the peak
luminosity may signal the evolution of the accretion rate. No tight correlation
between the shallow decay phase/plateau and prompt gamma-ray emission is found.
Assuming that they are due to a long-lasting wind injected by a compact object,
we show that the injected behavior favors the scenarios of a long-lasting wind
after the main burst episode. The peak luminosity of the afterglow onset is
tightly correlated with Eiso, and it is dimmer as peaking later. Assuming that
the onset bump is due to the fireball deceleration by the external medium, we
examine the Gamma_0-Eiso relation and find that it is confirmed with the
current sample. Optical re-brightening is observed in 30 GRBs in our sample. It
shares the same relation between the width and the peak time as found in the
onset bump, but no clear correlation between the peak luminosity and Eiso as
observed in the onset bumps is found. Although its peak luminosity also decays
with time, the slope is much shallower than that of the onset peak. We get L
t^{-1}_{p}$, being consistent with off-axis observations to an expanding
external fireball in a wind-like circum medium. The late re-brightening may
signal another jet component. Mixing of different emission components may be
the reason for the observed chromatic breaks in different energy bands.Comment: 10 pages, 5 figures, to be published by IJMPD (Proceedings of "The
Third Galileo - Xu Guangqi meeting", Beijing, October 11-15, 2011
On the Bethe states of the one-dimensional supersymmetric t-J model with generic open boundaries
By combining the algebraic Bethe ansatz and the off-diagonal Bethe ansatz, we
investigate the supersymmetric t-J model with generic open boundaries. The
eigenvalues of the transfer matrix are given in terms of an inhomogeneous T-Q
relation, and the corresponding eigenstates are expressed in terms of nested
Bethe states which have well-defined homogeneous limit. This exact solution
provides basis for further analyzing the thermodynamic properties and
correlation functions of the model.Comment: 17 pages, 2 tables, published versio
Robust Stabilization and H
This paper is concerned with the problem of robust stabilization and H∞ control for a class of uncertain neural networks. For the robust stabilization problem, sufficient conditions are derived based on the quadratic convex combination property together with Lyapunov stability theory. The feedback controller we design ensures the robust stability of uncertain neural networks with mixed time delays. We further design a robust H∞ controller which guarantees the robust stability of the uncertain neural networks with a given H∞ performance level. The delay-dependent criteria are derived in terms of LMI (linear matrix inequality). Finally, numerical examples are provided to show the effectiveness of the obtained results
Particle collisions in the lower dimensional rotating black hole space-time with the cosmological constant
In this paper, we study the effect of ultra-high energy collisions of two
particles with different energies near the horizon of a 2+1 dimensional BTZ
black hole (BSW effect). We find that the particle with the critical angular
momentum could exist inside the outer horizon of BTZ black hole regardless of
the particle energy. Therefore, for the non-extremal BTZ black hole, the BSW
process is possible on the inner horizon with the fine tuning of parameters
which are characterized by the motion of particle. While for the extremal BTZ
black hole, the particle with the critical angular momentum could only exist on
the degenerate horizon, and the BSW process could also happen there.Comment: 12 pages,3 figure
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