Photoproduction of Pentaquark Θ+\Theta^+ and Chiral Symmetry Restoration in Hot and Dense Medium

The photoproduction rate of pentaquark $\Theta^+$ is calculated in a hot and dense medium. At high temperature and density, due to the restoration of chiral symmetry, photoproduction energy threshold is increased. Above the thresold the production cross section is strongly enhanced.Comment: 5 pages, 3 figure

Meromorphic Parahoric Higgs Torsors and Filtered Stokes G-local Systems on Curves

In this paper, we consider the wild nonabelian Hodge correspondence for principal $G$-bundles on curves, where $G$ is a connected complex reductive group. We first give a version of Kobayashi--Hitchin correspondence, which induces a one-to-one correspondence between stable meromorphic parahoric Higgs torsors of degree zero (Dolbeault side) and stable meromorphic parahoric connections of degree zero (de Rham side). Then, by introducing a notion of stability condition on filtered Stokes local systems, we prove a one-to-one correspondence between stable meromorphic parahoric connections of degree zero (de Rham side) and stable filtered Stokes $G$-local systems of degree zero (Betti side). When $G={\rm GL}_n(\mathbb{C})$, the main result in this paper reduces to Biquad--Boalch's result.Comment: 26 page

Asymmetric Fermi Superfluid With Two Types Of Pairings

We investigate the phase diagram in the plane of temperature and chemical potential mismatch for an asymmetric fermion superfluid with double- and single-species pairings. There is no mixing of these two types of pairings at fixed chemical potential, but the introduction of the single species pairing cures the magnetic instability at low temperature.Comment: 6 pages, 1 figure. Proceedings of Poster Session, Quark Matter 2006, November 14-20, 2006, Shanghai, P.R.Chin

Torque-coupled thermodynamic model for F_oF_1-ATPase

F_oF_1-ATPase is a motor protein complex that utilizes transmembrane ion flow to drive the synthesis of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate (Pi). While many theoretical models have been proposed to account for its rotary activity, most of them focus on the F_o or F_1 portions separately rather than the complex as a whole. Here, we propose a simple but new torque-coupled thermodynamic model of F_oF_1-ATPase. Solving this model at steady state, we find that the monotonic variation of each portion's efficiency becomes much more robust over a wide range of parameters when the F_o and F_1 portions are coupled together, as compared to cases when they are considered separately. Furthermore, the coupled model predicts the dependence of each portion's kinetic behavior on the parameters of the other. Specifically, the power and efficiency of the F_1 portion are quite sensitive to the proton gradient across the membrane, while those of the F_o portion as well as the related Michaelis constants for proton concentrations respond insensitively to concentration changes in the reactants of ATP synthesis. The physiological proton gradient across the membrane in the F_o portion is also shown to be optimal for the Michaelis constants of ADP and phosphate in the F_1 portion during ATP synthesis. Together, our coupled model is able to predict key dynamic and thermodynamic features of the F_oF_1-ATPase in vivo semiquantitatively, and suggests that such coupling approach could be further applied to other biophysical systems

Scaling Relations for Galaxies Prior to Reionization

The first galaxies in the Universe are the building blocks of all observed galaxies. We present scaling relations for galaxies forming at redshifts $z \ge 15$ when reionization is just beginning. We utilize the ``Rarepeak' cosmological radiation hydrodynamics simulation that captures the complete star formation history in over 3,300 galaxies, starting with massive Population III stars that form in dark matter halos as small as ~$10^6 M_\odot$. We make various correlations between the bulk halo quantities, such as virial, gas, and stellar masses and metallicities and their respective accretion rates, quantifying a variety of properties of the first galaxies up to halo masses of $10^9 M_\odot$. Galaxy formation is not solely relegated to atomic cooling halos with virial temperatures greater than $10^4$ K, where we find a dichotomy in galaxy properties between halos above and below this critical mass scale. Halos below the atomic cooling limit have a stellar mass -- halo mass relationship $\log M_\star \simeq 3.5 + 1.3\log(M_{\rm vir} / 10^7 M_\odot)$. We find a non-monotonic relationship between metallicity and halo mass for the smallest galaxies. Their initial star formation events enrich the interstellar medium and subsequent star formation to a median of $10^{-2} Z_\odot$ and $10^{-1.5} Z_\odot$, respectively, in halos of total mass $10^7 M_\odot$ that is then diluted by metal-poor inflows, well beyond Population III pre-enrichment levels of $10^{-3.5} Z_\odot$. The scaling relations presented here can be employed in models of reionization, galaxy formation and chemical evolution in order to consider these galaxies forming prior to reionization.Comment: 10 pages, 10 figures. Accepted to Ap

Study on Preventive Maintenance Strategies of Filling Equipment Based on Reliability-Cantered Maintenance

In order to ensure normal operation of enterprise production activities and enhance the competitiveness of enterprise, equipment management and maintenance strategy formulation has always been one of important contents of daily management of enterprise. According to the actual requirement of a Chinese beer production enterprise, preventive maintenance strategy of filling equipment is put forward based on reliability-centred maintenance (RCM). Firstly, on the basis of analyzing RCM theory and equipment maintenance, the general process of failure analysis of beer production equipment is presented. Secondly, the general production process of bottled beer is analyzed, and the composition of major filling equipment is also introduced in the beer production line. With the help of key indicators of equipment reliability, such as mean time between failure (MTBF), mean time to repair restoration (MTTR) and availability Ai, the fault analysis of filling production line is carried out, and the relevant results are calculated. Then, process failure mode and effect analysis (PFMEA) of filling machine is implemented, and fault tree analysis (FTA) of potential failure modes with high risk priority numbers is also completed. Finally, preventive and maintenance strategies of filling equipment are established on the basis of RCM. Through the research in this paper, maintenance costs and unplanned breakdown hours can be significantly reduced