332 research outputs found

    DD correlations as a sensitive probe for thermalization in high-energy nuclear collisions

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    We propose to measure azimuthal correlations of heavy-flavor hadrons to address the status of thermalization at the partonic stage of light quarks and gluons in high-energy nuclear collisions. In particular, we show that hadronic interactions at the late stage cannot significantly disturb the initial back-to-back azimuthal correlations of DDbar pairs. Thus, a decrease or the complete absence of these initial correlations does indicate frequent interactions of heavy-flavor quarks and also light partons in the partonic stage, which are essential for the early thermalization of light partons

    Characterization and Inference of Gene Gain/Loss Along Burkholderia Evolutionary History

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    A comparative analysis of 60 complete Burkholderia genomes was conducted to obtain insight in the evolutionary history behind the diversity and pathogenicity at species level. A concatenated multiprotein phyletic pattern and a dataset with Burkholderia clusters of orthologous genes (BuCOGs) were constructed. The extent of horizontal gene transfer (HGT) was assessed using a Markov based probabilistic method. A reconstruction of the gene gains and losses history shows that more than half of the Burkholderia genes families are inferred to have experienced HGT at least once during their evolution. Further analysis revealed that the number of gene gain and loss was correlated with the branch length. Genomic islands (GEIs) analysis based on evolutionary history reconstruction not only revealed that most genes in ancient GEIs were gained but also suggested that the fraction of the genome located in GEIs in the small chromosomes is higher than in the large chromosomes in Burkholderia. The mapping of coexpressed genes onto biological pathway schemes revealed that pathogenicity of Burkholderia strains is probably mainly determined by the gained genes in its ancestor. Taken together, our results strongly support that gene gain and loss especially in ancient evolutionary history play an important role in strain divergence, pathogenicity determinants of Burkholderia and GEIs formation

    Production of Bulk Glassy Alloy Parts by a Levitation Melting-Forging Method

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    Ni 5 alloy parts with various shapes of coin, ring and dumbbell of 1 mm in thickness. The glassy alloy samples of 1 mm in thickness for tensile test were also produced by the LMF method. These samples were shaped directly from liquid without any intermediate process. The glassy structure in the samples examined by XRD and DSC is independent of sites. The results show the absence of partial crystallization in the glassy alloy coin prepared by LMF, however, a small quantity of crystallization is found in the glassy alloy coin prepared by copper mold casting. This may be due to the suppression of heterogeneous nucleation resulting from non-contact with container. The density of defects in the glassy alloys prepared by the LMF was decreased significantly because of the absence of spurt

    D-Dbar Correlations as a sensitive probe for thermalization in high-energy nuclear collisions

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    We propose to measure azimuthal correlations of heavy-flavor hadrons to address the status of thermalization at the partonic stage of light quarks and gluons in high-energy nuclear collisions. In particular, we show that hadronic interactions at the late stage cannot significantly disturb the initial back-to-back azimuthal correlations of DDbar pairs. Thus, a decrease or the complete absence of these initial correlations does indicate frequent interactions of heavy-flavor quarks and also light partons in the partonic stage, which are essential for the early thermalization of light partons.Comment: 5 pages, 4 figures. Version accepted for publication in Phys.Lett.

    Recent progress in 2D group-VA semiconductors: from theory to experiment

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    This review provides recent theoretical and experimental progress in the fundamental properties, electronic modulations, fabrications and applications of 2D group-VA materials.</p
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