465 research outputs found

    Critical exponents of finite temperature chiral phase transition in soft-wall AdS/QCD models

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    Criticality of chiral phase transition at finite temperature is investigated in a soft-wall AdS/QCD model with SUL(Nf)×SUR(Nf)SU_L(N_f)\times SU_R(N_f) symmetry, especially for Nf=2,3N_f=2,3 and Nf=2+1N_f=2+1. It is shown that in quark mass plane(mu/d−msm_{u/d}-m_s) chiral phase transition is second order at a certain critical line, by which the whole plane is divided into first order and crossover regions. The critical exponents β\beta and δ\delta, describing critical behavior of chiral condensate along temperature axis and light quark mass axis, are extracted both numerically and analytically. The model gives the critical exponents of the values β=12,δ=3\beta=\frac{1}{2}, \delta=3 and β=13,δ=3\beta=\frac{1}{3}, \delta=3 for Nf=2N_f=2 and Nf=3N_f=3 respectively. For Nf=2+1N_f=2+1, in small strange quark mass(msm_s) region, the phase transitions for strange quark and u/du/d quarks are strongly coupled, and the critical exponents are β=13,δ=3\beta=\frac{1}{3},\delta=3; when msm_s is larger than ms,t=0.290GeVm_{s,t}=0.290\rm{GeV}, the dynamics of light flavors(u,du,d) and strange quarks decoupled and the critical exponents for uˉu\bar{u}u and dˉd\bar{d}d becomes β=12,δ=3\beta=\frac{1}{2},\delta=3, exactly the same as Nf=2N_f=2 result and the mean field result of 3D Ising model; between the two segments, there is a tri-critical point at ms,t=0.290GeVm_{s,t}=0.290\rm{GeV}, at which β=0.250,δ=4.975\beta=0.250,\delta=4.975. In some sense, the current results is still at mean field level, and we also showed the possibility to go beyond mean field approximation by including the higher power of scalar potential and the temperature dependence of dilaton field, which might be reasonable in a full back-reaction model. The current study might also provide reasonable constraints on constructing a realistic holographic QCD model, which could describe both chiral dynamics and glue-dynamics correctly.Comment: 32 pages, 11 figures, regular articl

    The Prospect and Process of LNG

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    This report primarily addresses the issues surrounding a conventional onshore LNG receiving terminal and gives an overview of its chief components which include LNG unloading facilities, storage tanks, LNG (William, 1995) regasification system and vapor handling system. Report chiefly aims to the regasification process and infrastructures used in LNG receiving terminals, especially different types of vaporizers and storage tanks which being illustrated respectively in report. This report will be helpful in understanding the various technological aspects of conventional LNG receiving terminals

    Studying Malicious Websites and the Underground Economy on the Chinese Web

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    The World Wide Web gains more and more popularity within China with more than 1.31 million websites on the Chinese Web in June 2007. Driven by the economic profits, cyber criminals are on the rise and use the Web to exploit innocent users. In fact, a real underground black market with thousand of participants has developed which brings together malicious users who trade exploits, malware, virtual assets, stolen credentials, and more. In this paper, we provide a detailed overview of this underground black market and present a model to describe the market. We substantiate our model with the help of measurement results within the Chinese Web. First, we show that the amount of virtual assets traded on this underground market is huge. Second, our research proofs that a significant amount of websites within China’s part of the Web are malicious: our measurements reveal that about 1.49% of the examined sites contain some kind of malicious content

    Decomposition of Microbial Necromass Is Divergent at the Individual Taxonomic Level in Soil

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    The turnover of microbial biomass plays an important part in providing a significant source of carbon (C) to soil organic C. However, whether the decomposition of microbial necromass (non-living microbial biomass) in the soil varies at the individual taxa level remains largely unknown. To fill up these gaps, we compared the necromass decomposition of bacterial and archaeal taxa by separating live microbial biomass with 18O-stable isotope probing from dead microbial biomass in soil. Our results showed that most of the microbial necromass at the operational taxonomic unit level (88.51%), which mainly belong to Acidobacteria, Actinobacteria, Gemmatimonadetes, and Proteobacteria, decomposed significantly after 30 days. In addition, there were great variations in necromass decomposition within each phylum, such as the decomposition of operational taxonomic units in Proteobacteria that ranged from 51% (Beijerinckia) to 92% (Nitrosospira). More importantly, the necromass decomposition was not related to the chemical composition of the cell wall but might positively correlate with the guanine–cytosine content of DNA and negatively correlated with genome size. This study provided a new insight that the decomposition of microbial necromass in soil was divergent at the individual taxonomic level and could not be fully explained by previously proposed mechanisms

    Suppressing STAT3 activation impairs bone formation during maxillary expansion and relapse

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    Objectives: The mid-palatal expansion technique is commonly used to correct maxillary constriction in dental clinics. However, there is a tendency for it to relapse, and the key molecules responsible for modulating bone formation remain elusive. Thus, this study aimed to investigate whether signal transducer and activator of transcription 3 (STAT3) activation contributes to osteoblast-mediated bone formation during palatal expansion and relapse. Methodology: In total, 30 male Wistar rats were randomly allocated into Ctrl (control), E (expansion only), and E+Stattic (expansion plus STAT3-inhibitor, Stattic) groups. Micro-computed tomography, micromorphology staining, and immunohistochemistry of the mid-palatal suture were performed on days 7 and 14. In vitro cyclic tensile stress (10% magnitude, 0.5 Hz frequency, and 24 h duration) was applied to rat primary osteoblasts and Stattic was administered for STAT3 inhibition. The role of STAT3 in mechanical loading-induced osteoblasts was confirmed by alkaline phosphatase (ALP), alizarin red staining, and western blots. Results: The E group showed greater arch width than the E+Stattic group after expansion. The differences between the two groups remained significant after relapse. We found active bone formation in the E group with increased expression of ALP, COL-I, and Runx2, although the expression of osteogenesis-related factors was downregulated in the E+stattic group. After STAT3 inhibition, expansive force-induced bone resorption was attenuated, as TRAP staining demonstrated. Furthermore, the administration of Stattic in vitro partially suppressed tensile stress-enhanced osteogenic markers in osteoblasts. Conclusions: STAT3 inactivation reduced osteoblast-mediated bone formation during palatal expansion and post-expansion relapse, thus it may be a potential therapeutic target to treat force-induced bone formation
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