Complete analysis on QED corrections to Bq → τ+ τ−B_{q}\, \to\, \tau^+\, \tau^-

Motivated by a dynamical enhancement of the electromagnetic corrections by a power of $\Lambda_{\mathrm{QCD}}/m_b$ in $B_{d,s}\, \to\, \mu^+\, \mu^-$ at next-to-leading order (NLO), we extend the QED factorization effects on the leptonic $B$ meson decays with light muon leptons to tauonic final states, $B_{d,s} \, \to\, \tau^+\, \tau^-$, using soft-collinear effective theory (SCET). This extension is necessary owing to the appearance of the large $\tau$ mass, which will lead to different power counting in SCET and also different results. We provide a complete NLO electromagnetic corrections to $B_{d,s} \, \to\, \tau^+\, \tau^-$, which include hard functions and hard-collinear functions below the bottom quark mass scale $\mu_b$. The power enhanced electromagnetic effects from hard-collinear contributions on $B_{d,s}\, \to\, \mu^+\, \mu^-$ discussed before also exist in $B_{d,s} \, \to\, \tau^+\, \tau^-$. However the logarithm term arising from contributions of hard-collinear photon and lepton virtualities for $B_{d,s}\, \to\, \tau^+\, \tau^-$ is not large as it is in muon case due to the hard-collinear scale of $\tau$ mass, which lead to only approximately $0.04\%$ QED corrections to the branching fraction of $B_{d,s} \, \to\, \tau^+\, \tau^-$ compared with overall reduction about $0.5\%$ in $B_{d,s}\, \to\, \mu^+\, \mu^-$.Comment: 29 pages, 3 figure

Sevoflurane improves gaseous exchange and exerts protective effects in lipopolysaccharide-induced lung injury in mice models

Purpose: To investigate the protective effect of sevoflurane against lipopolysaccharide (LPS)-induced acute liver injury (ALI) in amice model.Methods: Seven week-old female BalB/C mice were used. Lung water content and cell count were estimated by standard protocols. Cytokine and chemokine analysis was performed using commercially available kits. Myeloperoxidase activity was evaluated spectrophotometrically while histopathological analysis was carried out by H and E staining.Results: The results revealed that sevoflurane treatment significantly improved gaseous exchange, and reduced lung water content and lung inflammation as evidenced by a decrease in neutrophil migration into BALF (p < 0.01). Sevoflurane also significantly reversed the LPS-triggered suppression of IL-10 in the lung tissues of LPS-treated mice, when compared to saline-treated controls (p < 0.01). It reversed LPS-induced oxidative stress, as demonstrated by increase in total antioxidant capacity (T-AC), catalase (CAT) and superoxide dismutase-1 (SOD-1), as well as an increase in reduced/oxidized glutathione (GSH/GSSG) ratio. In addition, sevoflurane blocked LPS-induced lung tissue injury in ALI mice, and exerted protective effects against acute LPS-induced lung injury.Conclusion: These results suggest that sevoflurane improves gaseous exchange and exerts a protective effect against LPS-triggered lung injury in mice model, most probably due to its antiinflammatory and antioxidant properties.Keywords: Lung injury, Sevoflurane, Respiratory distress, Superoxide dismutase, Liposaccharid

Terminal Sliding Mode Control for Attitude Tracking of Spacecraft Based on Rotation Matrix

Two finite-time controllers without unwinding for the attitude tracking control of the spacecraft are investigated based on the rotation matrix, in which a novel modified nonsingular fast terminal sliding manifold is developed to keep tr(R~)≠-1. The first terminal sliding mode controller can compensate external disturbances with known bounds, while the second one can compensate external disturbances with unknown bounds by using an adaptive control method. Since the first terminal sliding mode controller is continuous, it is able to avoid chattering phenomenon. Theoretical analysis shows that both the two controllers can make spacecraft follow a time-varying reference attitude signal in finite time. Numerical simulations also demonstrate that the proposed control schemes are effective

A Sodium laser guide star coupling efficiency measurement method

Large telescope's adaptive optics (AO) system requires one or several bright artificial laser guide stars to improve its sky coverage. The recent advent of high power sodium laser is perfect for such application. However, besides the output power, other parameters of the laser also have significant impact on the brightness of the generated sodium laser guide star mostly in non-linear relationships. When tuning and optimizing these parameters it is necessary to tune based on a laser guide star generation performance metric. Although return photon flux is widely used, variability of atmosphere and sodium layer make it difficult to compare from site to site even within short time period for the same site. A new metric, coupling efficiency is adopted in our field tests. In this paper, we will introduce our method for measuring the coupling efficiency of a 20W class pulse sodium laser for AO application during field tests that were conducted during 2013-2015

A Global Optimization Algorithm for Signomial Geometric Programming Problem

This paper presents a global optimization algorithm for solving the signomial geometric programming (SGP) problem. In the algorithm, by the straight forward algebraic manipulation of terms and by utilizing a transformation of variables, the initial nonconvex programming problem (SGP) is first converted into an equivalent monotonic optimization problem and then is reduced to a sequence of linear programming problems, based on the linearizing technique. To improve the computational efficiency of the algorithm, two range reduction operations are combined in the branch and bound procedure. The proposed algorithm is convergent to the global minimum of the (SGP) by means of the subsequent solutions of a series of relaxation linear programming problems. And finally, the numerical results are reported to vindicate the feasibility and effectiveness of the proposed method

Ductile fracture and microstructure of a bearing steel in hot tension

Ductile fracture, such as micro-cavities and micro-voids, inevitably exist and evolve under tensile stress state in metal forming. Ductile fracture sways the mechanical performance of 52100 bearing steel. It is necessary to investigate the influences of strain rate and deformation temperature on both ductile fracture and microstructure evolution. Uniaxial hot tension tests were performed, in which specimens were stretched to failure in the temperatures range from 950 C to 1160 C and in the strain rates range from 0.01 /s to 1.0 /s. Specimens metallographies have been explored after hot tension. Experimental results show that the peak stress decreases when deformation temperature increases and strain rate decreases. The critical strain of stress–strain relationships increases when strain rate increases. Fracture morphology is severe at higher deformation temperatures and lower strain rates. Hot tension deformation capacity is worst at 1160 C and a strain rate of 0.01 /s, has been caused by a larger and coarser grain structure

Ductile fracture and microstructure of a bearing steel in hot tension

382-388Ductile fracture, such as micro-cavities and micro-voids, inevitably exist and evolve under tensile stress state in metal forming. Ductile fracture sways the mechanical performance of 52100 bearing steel. It is necessary to investigate the influences of strain rate and deformation temperature on both ductile fracture and microstructure evolution. Uniaxial hot tension tests were performed, in which specimens were stretched to failure in the temperatures range from 950 °C to 1160 °C and in the strain rates range from 0.01 /s to 1.0 /s. Specimens metallographies have been explored after hot tension. Experimental results show that the peak stress decreases when deformation temperature increases and strain rate decreases. The critical strain of stress–strain relationships increases when strain rate increases. Fracture morphology is severe at higher deformation temperatures and lower strain rates. Hot tension deformation capacity is worst at 1160 °C and a strain rate of 0.01 /s, has been caused by a larger and coarser grain structure

A Search for Double-peaked narrow emission line Galaxies and AGNs in the LAMOST DR1

LAMOST has released more than two million spectra, which provide the opportunity to search for double-peaked narrow emission line (NEL) galaxies and AGNs. The double-peaked narrow-line profiles can be well modeled by two velocity components, respectively blueshifted and redshifted with respect to the systemic recession velocity. This paper presents 20 double-peaked NEL galaxies and AGNs found from LAMOST DR1 using a search method based on multi-gaussian fit of the narrow emission lines. Among them, 10 have already been published by other authors, either listed as genuine double-peaked NEL objects or as asymmetric NEL objects, the remaining 10 being first discoveries. We discuss some possible origins for double-peaked narrow-line features, as interaction between jet and narrow line regions, interaction with companion galaxies and black hole binaries. Spatially resolved optical imaging and/or follow-up observations in other spectral bands are needed to further discuss the physical mechanisms at work.Comment: 17 pages, 5figures, 4 tables, accepted by RA