5,693 research outputs found

    Analysis of Y(4660) and related bound states with QCD sum rules

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    In this article, we take the vector charmonium-like state Y(4660) as a ψf0(980)\psi'f_0(980) bound state (irrespective of the hadro-charmonium and the molecular state) tentatively, study its mass using the QCD sum rules, the numerical value MY=4.71±0.26GeVM_Y=4.71\pm0.26 \rm{GeV} is consistent with the experimental data. Considering the SU(3) symmetry of the light flavor quarks and the heavy quark symmetry, we also study the bound states ψσ(4001200)\psi'\sigma(400-1200), Υ"f0(980)\Upsilon'"f_0(980) and Υ"σ(4001200)\Upsilon"'\sigma(400-1200) with the QCD sum rules, and make reasonable predictions for their masses.Comment: 18 pages, 32 figures, revised versio

    Momentum-space electronic structures and charge orders of high-temperature superconductors Ca2-xNaxCuO2Cl2 and Bi2Sr2CaCu2O8+delta

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    We study the electronic structure of Ca2-xNaxCuO2Cl2 and Bi2Sr2CaCu2O8+d samples in a wide range of doping, using angle-resolved photoemission spectroscopy, with emphasis on on the Fermi surface (FS) in the near anti-nodal region. The "nesting wave vector", i.e., the wave vector that connects two nearly flat pieces of the Fermi surface in the anti-nodal region, reveals a universal monotonic decrease in magnitude as a function of doping. Comparing our results to the charge order recently observed by scanning tunneling spectroscopy (STS), we conclude that the FS nesting and the charge order pattern seen in STS do not have a direct relationship. Therefore,the charge order likely arises due to strong correlation physics rather than FS nesting physics.Comment: 6 pages, 4 figure

    Moving finite element simulations for reaction-diffusion systems

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    2011-2012 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    Influence of Rotation on Pulsar Radiation Characteristics

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    We present a relativistic model for pulsar radio emission by including the effect of rotation on coherent curvature radiation by bunches. We find that rotation broadens the width of leading component compared to the width of trailing component. We estimate the component widths in the average pulse profiles of about 24 pulsars, and find that 19 of them have a broader leading component. We explain this difference in the component widths by using the nested cone emission geometry. We estimate the effect of pulsar spin on the Stokes parameters, and find that the inclination between the rotation and magnetic axes can introduce an asymmetry in the circular polarization of the conal components. We analyze the single pulse polarization data of PSR B0329+54 at 606 MHz, and find that in its conal components, one sense of circular polarization dominates in the leading component while the other sense dominates in the trailing component. Our simulation shows that changing the sign of the impact parameter changes the sense of circular polarization as well as the swing of polarization angle.Comment: 20 pages, 4 Postscript figures, uses aastex.cls. Accepted for Publication in ApJ 200

    Paleoseismology of the Xorxol Segment of the Central Altyn Tagh Fault, Xinjiang, China

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    Although the Altyn Tagh Fault (ATF) is thought to play a key role in accommodating India-Eurasian convergence, little is known about its earthquake history. Studies of this strike-slip fault are important for interpretation of the role of faulting versus distributed deformation in the accommodation of the India- Eurasia collision. In addition, the > 1200 km long fault represents one of the most important and exemplary intracontinental strike-slip faults in the world. We mapped fault trace geometry and interpreted paleoseismic trench exposures to characterize the seismogenic behavior of the ATF. We identified 2 geometric segment boundaries in a 270 km long reach of the central ATF. These boundaries define the westernmost Wuzhunxiao, the Central Pingding, and the easternmost Xorxol (also written as Suekuli or Suo erkuli) segments. In this paper, we present the results from the Camel paleoseismic site along the Xorxol Segment at 91.759°E, 38.919°N. There evidence for the last two earthquakes is clear and 14C dates from layers exposed in the excavation bracket their ages. The most recent earthquake occurred between 1456 and 1775 cal A.D. and the penultimate event was between 60 and 980 cal A.D. Combining the Camel interpretations with our published results for the central ATF, we conclude that multiple earthquakes with shorter rupture lengths (?? 50 km) rather than complete rupture of the Xorxol Segment better explain the paleoseismic data. We found 2-3 earthquakes in the last 2-3 kyr. When coupled with typical amounts of slip per event (5-10 m), the recurrence times are tentatively consistent with 1-2 cm/yr slip rates. This result favors models that consider the broader distribution of collisional deformation, rather than those with northward motion of India into Asia absorbed along a few faults bounding rigid blocks

    Endothelial protein C receptor in renal tubular epithelial cells and influencing factors

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    The endothelial protein C receptor (EPCR) plays an important role within the protein C pathway in regulating coagulation and inflammation. It was reported that EPCR was expressed in large vessels, placenta, heart, liver and lung endothelial cell. However, there are a few studies concerned about renal epithelial cells. This study aims to investigate EPCR expression in renal tubular epithelial cells and related influencing factors. EPCR expression was assessed by flow cytometry in renal tubular epithelial cells. The effects of some reagents (high glucose, tumor necrosis factor–α and interleukin-1β) were measured by RT-PCR. The results showed that renal tubular epithelial cells had the high expression of EPCR level. High glucose, tumor necrosis factor–α and interleukin-1β might reduce EPCR expression. And troglitazone could significantly improve the inhibition. In conclusion, we found EPCR expression in renal tubular epithelial cells in vitro. Some factors such as high glucose, tumor necrosis factor–α and interleukin-1β can impact on EPCR. However, troglitazone had protective effects of EPCR on injured cells.Key words: Endothelial protein C receptor, renal tubular epithelial cell, troglitazone, tumor necrosis factor-α, interleukin-1β; high glucose
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