420 research outputs found
Quantifying Properties of the QCD Matter at RHIC
We will review recent results on quantitative description of global
properties of bulk partonic matter at RHIC. These results include strangeness
phase space factor of the partonic matter, azimuthal angular anisotropy ,
and transverse momentum distributions of effective partons at the
hadronization of bulk partonic matter. We present empirical constraints on
parton energy loss in the high region ( 5 GeV/c). A flat as a
function of at mid-rapidity implies a constant fraction of the parton
energy loss () and the fraction reaches 25% for neutral ,
charged hadrons and non-photonic electrons of heavy quark decays from central
Au+Au collisions at 200 GeV. Collision centrality dependence of
from Au+Au and Cu+Cu collisions indicates that the fraction is
approximately proportional to particle rapidity density divided by the
initial transverse overlapping area of the colliding nuclei. Implications on
dynamics of parton energy loss will be discussed.Comment: To Appear in SQM2008 Conference Proceeding
The Application of the Multiple Points of a Mold Function of UG MoldWizard in the Design of Cutting Compressor
In recent years, mold industry develops rapidly. The design and manufacture of mold have become an important symbol to measure the level of a country#39s manufacturing industry. Difficult point in the design of the cutting compressor for recycling plastic bottles lies in cutting and compressing plastic bottles at the same time. Use UG MoldWizard to design the working process of injection mold. Design and manufacture the U-lower plastic mold with the aid of a computer. Make optimal design plan of the U-lower plastic in the cutting compressor
GeV antiproton/gamma-ray excesses and the -boson mass anomaly: three faces of GeV dark matter particle?
For the newly discovered -boson mass anomaly, one of the simplest dark
matter (DM) models that can account for the anomaly without violating other
astrophysical/experimental constraints is the inert two Higgs doublet model, in
which the DM mass () is found to be within GeV. In this
model, the annihilation of DM via and would
produce antiprotons and gamma rays, and may account for the excesses identified
previously in both particles. Motivated by this, we re-analyze the AMS-02
antiproton and Fermi-LAT Galactic center gamma-ray data. For the antiproton
analysis, the novel treatment is the inclusion of the charge-sign-dependent
three-dimensional solar modulation model as constrained by the time-dependent
proton data. We find that the excess of antiprotons is more distinct than
previous results based on the force-field solar modulation model. The
interpretation of this excess as the annihilation of () requires a DM mass of () GeV and a
velocity-averaged cross section of . As for the
-ray data analysis, rather than adopting the widely-used spatial
template fitting, we employ an orthogonal approach with a data-driven spectral
template analysis. The fitting to the GeV -ray excess yields DM model
parameters overlapped with those to fit the antiproton excess via the
channel. The consistency of the DM particle properties required to account for
the -boson mass anomaly, the GeV antiproton excess, and the GeV -ray
excess suggest a common origin of them.Comment: 8 page
Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single crystals with x=0 - 0.4
Single crystals of AKFeAs (A=Ba, Sr) with high quality
have been grown successfully by FeAs self-flux method. The samples have sizes
up to 4 mm with flat and shiny surfaces. The X-ray diffraction patterns suggest
that they have high crystalline quality and c-axis orientation. The
non-superconducting crystals show a spin-density-wave (SDW) instability at
about 173 K and 135 K for Sr-based and Ba-based compound, respectively. After
doping K as the hole dopant into the BaFeAs system, the SDW transition
is smeared, and superconducting samples with the compound of
BaKFeAs (0 0.4) are obtained. The
superconductors characterized by AC susceptibility and resistivity measurements
exhibit very sharp superconducting transition at about 36 K, 32 K, 27 K and 23
K for x= 0.40,0.28,0.25 and 0.23, respectively.Comment: 9 pages, 6 figures, 1 table. This paper together with new data are
modified into a new pape
-scaling and Information Entropy in Ultra-Relativistic Nucleus-Nucleus Collisions
The -scaling method has been applied to ultra-relativistic p+p, C+C
and Pb+Pb collision data simulated using a high energy Monte Carlo package,
LUCIAE 3.0. The -scaling is found to be valid for some physical
variables, such as charged particle multiplicity, strange particle multiplicity
and number of binary nucleon-nucleon collisions from these simulated
nucleus-nucleus collisions over an extended energy ranging from = 20
to 200 A GeV. In addition we derived information entropy from the multiplicity
distribution as a function of beam energy for these collisions.Comment: 4 pages, 4 figures, 1 table; to appear in the July Issue of Chin.
Phys. Lett.. Web Page: http://www.iop.org/EJ/journal/CP
Trafficking-Deficient G572R-hERG and E637K-hERG Activate Stress and Clearance Pathways in Endoplasmic Reticulum
Background: Long QT syndrome type 2 (LQT2) is the second most common type of all long QT syndromes. It is well-known that trafficking deficient mutant human ether-a-go-go-related gene (hERG) proteins are often involved in LQT2. Cells respond to misfolded and trafficking-deficient proteins by eliciting the unfolded protein response (UPR) and Activating Transcription Factor (ATF6) has been identified as a key regulator of the mammalian UPR. In this study, we investigated the role of ER chaperone proteins (Calnexin and Calreticulin) in the processing of G572R-hERG and E637K-hERG mutant proteins. Methods: pcDNA3-WT-hERG, pcDNA3-G572R-hERG and pcDNA3-E637K-hERG plasmids were transfected into U2OS and HEK293 cells. Confocal microscopy and western blotting were used to analyze subcellular localization and protein expression. Interaction between WT or mutant hERGs and Calnexin/Calreticulin was tested by coimmunoprecipitation. To assess the role of the ubiquitin proteasome pathway in the degradation of mutant hERG proteins, transfected HEK293 cells were treated with proteasome inhibitors and their effects on the steady state protein levels of WT and mutant hERGs were examined. Conclusion: Our results showed that levels of core-glycosylated immature forms of G572R-hERG and E637K-hERG in association with Calnexin and Calreticulin were higher than that in WT-hERG. Both mutant hERG proteins could activate the UPR by upregulating levels of active ATF6. Furthermore, proteasome inhibition increased the levels of core-glycosylated immature forms of WT and mutant hERGs. In addition, interaction between mutant hERGs and Calnexin/Calreticulin wa
Grain engineering of Sb2S3 thin films to enable efficient planar solar cells with high open-circuit voltage
Sb2S3 is a promising environmentally friendly semiconductor for high performance solar cells. But, like many other polycrystalline materials, Sb2S3 is limited by nonradiative recombination and carrier scattering by grain boundaries (GBs). This work shows how the GB density in Sb2S3 films can be significantly reduced from 1068 ± 40 to 327 ± 23 nm µm−2 by incorporating an appropriate amount of Ce3+ into the precursor solution for Sb2S3 deposition. Through extensive characterization of structural, morphological, and optoelectronic properties, complemented with computations, it is revealed that a critical factor is the formation of an ultrathin Ce2S3 layer at the CdS/Sb2S3 interface, which can reduce the interfacial energy and increase the adhesion work between Sb2S3 and the substrate to encourage heterogeneous nucleation of Sb2S3, as well as promote lateral grain growth. Through reductions in nonradiative recombination at GBs and/or the CdS/Sb2S3 heterointerface, as well as improved charge-carrier transport properties at the heterojunction, this work achieves high performance Sb2S3 solar cells with a power conversion efficiency reaching 7.66%. An impressive open-circuit voltage (VOC) of 796 mV is achieved, which is the highest reported thus far for Sb2S3 solar cells. This work provides a strategy to simultaneously regulate the nucleation and growth of Sb2S3 absorber films for enhanced device performance
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