6,742 research outputs found
Rapidity bin multiplicity correlations from a multi-phase transport model
The central-arbitrary bin and forward-backward bin multiplicity correlation
patterns for Au+Au collisions at = GeV are
investigated within a multi-phase transport (AMPT) model. An interesting
observation is that for GeV Au+Au collisions, these two
correlation patterns both have an increase with the pseudorapidity gap, while
for GeV Au+Au collisions, they decrease. We mainly
discuss the influence of different evolution stages of collision system on the
central-arbitrary bin correlations, such as the initial conditions, partonic
scatterings, hadronization scheme and hadronic scatterings. Our results show
that the central-arbitrary bin multiplicity correlations have different
responses to partonic phase and hadronic phase, which can be suggested as a
good probe to explore the dynamical evolution mechanism of the hot dense matter
in high-energy heavy-ion collisions.Comment: 7pages, 6 figures, accepted for publication in EPJ
Fermionic phase transition induced by the effective impurity in holography
We investigate the holographic fermionic phase transition induced by the
effective impurity in holography, which is introduced by massless scalar fields
in Einstein-Maxwell-massless scalar gravity. We obtain a phase diagram in
plane separating the Fermi liquid phase and the non-Fermi liquid
phase.Comment: 17 pages, 9 figure
A WENO Algorithm of the Temperature and Ionization Profiles around a Point Source
We develop a numerical solver for radiative transfer problems based on the
weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive
flux corrections, in order to solve the temperature and ionization profiles
around a point source of photons in the reionization epoch. Algorithms for such
simulation must be able to handle the following two features: 1. the sharp
profiles of ionization and temperature at the ionizing front (I-front) and the
heating front (T-front), and 2. the fraction of neutral hydrogen within the
ionized sphere is extremely small due to the stiffness of the rate equations of
atom processes. The WENO scheme can properly handle these two features, as it
has been shown to have high order of accuracy and good convergence in capturing
discontinuities and complicated structures in fluid as well as to be
significantly superior over piecewise smooth solutions containing
discontinuities. With this algorithm, we show the time-dependence of the
preheated shell around a UV photon source. In the first stage the I-front and
T-front are coincident, and propagate with almost the speed of light. In later
stage, when the frequency spectrum of UV photons is hardened, the speeds of
propagation of the ionizing and heating fronts are both significantly less than
the speed of light, and the heating front is always beyond the ionizing front.
In the spherical shell between the I- and T-fronts, the IGM is heated, while
atoms keep almost neutral. The time scale of the preheated shell evolution is
dependent on the intensity of the photon source. We also find that the details
of the pre-heated shell and the distribution of neutral hydrogen remained in
the ionized sphere are actually sensitive to the parameters used. The WENO
algorithm can provide stable and robust solutions to study these details.Comment: 24 pages, 7 figures, accepted in New Astronom
Anomalous pressure behavior of tangential modes in single-wall carbon nanotubes
Using the molecular dynamics simulations and the force constant model we have
studied the Raman-active tangential modes (TMs) of a (10, 0) single-wall carbon
nanotube (SWNT) under hydrostatic pressure. With increasing pressure, the
atomic motions in the three TMs present obvious diversities. The pressure
derivative of E1g, A1g, and E2g mode frequency shows an increased value (), a
constant value (), and a negative value () above 5.3 GPa, respectively. The
intrinsic characteristics of TMs consumedly help to understand the essence of
the experimental T band of CNT. The anomalous pressure behavior of the TMs
frequencies may be originated from the tube symmetry alteration from D10h to
D2h then to C2h.Comment: 15 pages, 3 pages, submitted to Phys. Rev.
Effects of coagulation factors and inflammatory cytokines on development of acute myocardial infarction in patients younger than 60 years
Purpose: To investigate the effects of coagulation factors and inflammatory cytokines on acute myocardial infarction (AMI) development in patients younger than 60 years.Methods: In this study, 60 patients admitted to The First Affiliated Hospital of Dalian Medical University (Dalian, China) with AMI and 30 other subjects matched with the patients for age and ethnicity but without AMI were enrolled. Blood samples were collected from the AMI patients and the control subjects after a 12-h fast. Subsequently, the levels of coagulation factors (F) II (FII), VII (FVII), VIII (FVIII), fibrinogen (Fg) and von Willebrand factor (vWF) in plasma were analyzed by enzyme-linked immunosorbent assay (ELISA). The protein expression levels of these coagulation factors were determined by Western blot analysis. Inflammatory factors including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and interleukin- 6 (IL-6) were also measured by ELISA.Results: FII, FVII, FVIII, Fg and vWF levels in plasm were significantly higher in AMI patients compared with control subjects (p < 0.01). Furthermore, the protein expression levels of FII, FVII, FVIII, Fg and vWF were also significantly up-regulated in AMI patients compared with those in control subjects. Additionally, no significant difference was observed in CRP between AMI patients and control subjects (p > 0.05). However, TNF-α and IL-6 levels in the plasma of AMI patients were significantly higher than those in control subjects (p < 0.05).Conclusion: The results reveal that the pathogenesis of AMI in patients younger than 60 years might be closely related to the high levels of coagulation factors and inflammatory cytokines in the blood.Keywords: Coagulation factor, Inflammatory cytokines, Acute myocardial infarction, C-reactive protein, Tumor necrosis factor-α, Interleukin-
Epigallocatechin-3-gallate (EGCG) inhibits imiquimod-induced psoriasis-like inflammation of BALB/c mice
Trace initial interaction from final state observable in relativistic heavy ion collisions
In order to trace the initial interaction in ultra-relativistic heavy ion
collision in all azimuthal directions, two azimuthal multiplicity-correlation
patterns -- neighboring and fixed-to-arbitrary angular-bin correlation patterns
-- are suggested. From the simulation of Au + Au collisions at 200 GeV by using
the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without
string melting, we observe that the correlation patterns change gradually from
out-of-plane preferential one to in-plane preferential one when the centrality
of collision shifts from central to peripheral, meanwhile the anisotropic
collective flow v_2 keeps positive in all cases. This regularity is found to be
model and collision energy independent. The physics behind the two opposite
trends of correlation patterns, in particular, the presence of out-of-plane
correlation patterns at RHIC energy, are discussed.Comment: 5pages, 4figure
3-(4-Fluorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one
The title compound, C16H13FO2, was prepared from 4-methoxyhypnone and 4-fluorobenzophenone by Claisen–Schmidt condensation. All the bond lengths and bond angles are in normal ranges. The dihedral angle formed by the two benzene rings is 33.49 (2)°. The crystal packing is stabilized by intermolecular C—H⋯O hydrogen-bonding interactions
Target-Mounted Intelligent Reflecting Surface for Joint Location and Orientation Estimation
Intelligent reflecting surface (IRS) has been widely recognized as an
efficient technique to reconfigure the electromagnetic environment in favor of
wireless communication performance. In this paper, we propose a new application
of IRS for device-free target sensing via joint location and orientation
estimation. In particular, different from the existing works that use IRS as an
additional anchor node for localization/sensing, we consider mounting IRS on
the sensing target, whereby estimating the IRS's location and orientation as
that of the target by leveraging IRS's controllable signal reflection. To this
end, we first propose a tensor-based method to acquire essential angle
information between the IRS and the sensing transmitter as well as a set of
distributed sensing receivers. Next, based on the estimated angle information,
we formulate two optimization problems to estimate the location and orientation
of the IRS/target, respectively, and obtain the locally optimal solutions to
them by invoking two iterative algorithms, namely, gradient descent method and
manifold optimization. In particular, we show that the orientation estimation
problem admits a closed-form solution in a special case that usually holds in
practice. Furthermore, theoretical analysis is conducted to draw essential
insights into the proposed sensing system design and performance. Simulation
results verify our theoretical analysis and demonstrate that the proposed
methods can achieve high estimation accuracy which is close to the theoretical
bound.Comment: 30page
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