5,046 research outputs found

    On the Common Envelope Efficiency

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    In this work, we try to use the apparent luminosity versus displacement (i.e., LXL_{\rm X} vs. RR) correlation of high mass X-ray binaries (HMXBs) to constrain the common envelope (CE) efficiency αCE\alpha_{\rm CE}, which is a key parameter affecting the evolution of the binary orbit during the CE phase. The major updates that crucial for the CE evolution include a variable λ\lambda parameter and a new CE criterion for Hertzsprung gap donor stars, both of which are recently developed. We find that, within the framework of the standard energy formula for CE and core definition at mass X=10X=10\%, a high value of αCE\alpha_{\rm CE}, i.e., around 0.8-1.0, is more preferable, while αCE<∼0.4\alpha_{\rm CE}< \sim 0.4 likely can not reconstruct the observed LXL_{\rm X} vs. RR distribution. However due to an ambiguous definition for the core boundary in the literature, the used λ\lambda here still carries almost two order of magnitude uncertainty, which may translate directly to the expected value of αCE\alpha_{\rm CE}. We present the detailed components of current HMXBs and their spatial offsets from star clusters, which may be further testified by future observations of HMXB populations in nearby star-forming galaxies.Comment: 14 pages, 10 figures, 7 tables, accepted for publication in MNRA

    Nonextensive effects on QCD chiral phase diagram and baryon-number fluctuations within Polyakov-Nambu-Jona-Lasinio model

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    In this paper, a version of the Polyakov-Nambu-Jona-Lasinio (PNJL) model based on nonextensive statistical mechanics is presented. This new statistics summarizes all possible factors that violate the assumptions of the Boltzmann-Gibbs (BG) statistics to a dimensionless nonextensivity parameter qq, and when qq tends to 1, it returns to the BG case. Within the nonextensive PNJL model, we found that as qq increases, the location of the critical end point (CEP) exhibits non-monotonic behavior. That is, for q<1.15q<1.15, CEP moves in the direction of lower temperature and larger quark chemical potential. But for q>1.15q>1.15, CEP turns to move in the direction of lower temperature and lower quark chemical potential. In addition, we studied the moments of the net-baryon number distribution, that is, the variance (σ2\sigma^{2}), skewness (S), and kurtosis (κ\kappa). Our results are generally consistent with the latest experimental data, especially for SNN>19.6 GeV\sqrt{S_{NN}}>19.6\ \mathrm{GeV}, when qq is set to 1.071.07

    3-[(3,5-Di-tert-butyl-2-hydroxy­benzyl­idene)methyl­eneamino]benzonitrile

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    The mol­ecule of the title compound, C22H26N2O, displays a trans configuration with respect to the C=N double bond. The dihedral angle between the planes of the two aromatic rings is 26.30 (15)°. There is a strong intra­molecular O—H⋯N hydrogen bond between the imine and hydroxyl groups

    Pseudomonas aeruginosa ecthyma gangrenosum in a woman with recurrent Graves’ disease

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    SummaryA 35-year-old woman with postoperative recurrent Graves’ disease presented with a 5-day history of a red swelling on the right cheek associated with 4 days of remittent hyperpyrexia. Investigations revealed fever, a gangrenous ulcer on the right cheek, submandibular lymphadenopathy, and thyroid gland enlargement. Her white blood cell count, immunoglobulins, and lymphocyte subsets were unremarkable. Thyroid function tests showed low thyroid-stimulating hormone, high free thyroxine, and elevated radioactive iodine uptake. Repeated pus cultures grew Pseudomonas aeruginosa, but blood cultures were negative. An ill-demarcated erythematous plaque occurred on the right leg on hospital day 3. She was treated with intravenous antibiotics with topical gentamicin, recombinant bovine basic fibroblast growth factor, and radioiodine therapy with anti-thyroid drugs. The ulcer healed leaving a depressed scar at 35 days after discharge. This patient may represent the first case of P. aeruginosa ecthyma gangrenosum and cellulitis in postoperative recurrent Graves’ disease
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