4,080 research outputs found

    Bs0βˆ’BΛ‰s0B_s^0-\bar{B}_s^0 mixing within minimal flavor-violating two-Higgs-doublet models

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    In the "Higgs basis" for a generic 2HDM, only one scalar doublet gets a nonzero vacuum expectation value and, under the criterion of minimal flavor violation, the other one is fixed to be either color-singlet or color-octet, which are named as the type-III and type-C models, respectively. In this paper, the charged-Higgs effects of these two models on Bs0βˆ’BΛ‰s0B_s^0-\bar{B}_s^0 mixing are studied. Firstly, we perform a complete one-loop computation of the electro-weak corrections to the amplitudes of Bs0βˆ’BΛ‰s0B_s^0-\bar{B}_s^0 mixing. Together with the up-to-date experimental measurements, a detailed phenomenological analysis is then performed in the cases of both real and complex Yukawa couplings of charged scalars to quarks. The spaces of model parameters allowed by the current experimental data on Bs0βˆ’BΛ‰s0B_s^0-\bar{B}_s^0 mixing are obtained and the differences between type-III and type-C models are investigated, which is helpful to distinguish between these two models.Comment: 19 pages, 3 figures, 2 tables; More references and discussions added, final version published in the journa

    Dynamic Properties of Saturated Coal Fly Ash

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    The great part of fly ash produced by thermal power plants is either sluiced or filled in disposal areas in China. The dynamic properties of fly ash are important for solving geotechnical problems relating to fly ash mass under dynamic loadings. The high temperature during combustion makes fly ash nonplastic but pozzolanic. The nonplasticity causes the dynamic properties of sluiced and just compacted fly ash to be similar to ones of silts. The pozzolanic action causes obvious aging effect for compacted fly ash, by which an aging time of 180 days may increase maximum shear modulus by 75% to 400% and cyclic strength by 100% to 500%. All of these results are reported and discussed in the paper in detail. Based on the results four correlative equations are presented which could be used to preliminarily evaluate the dynamic properties of fly ashes

    Inclusive weak-annihilation decays and lifetimes of beauty-charmed baryons

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    Imbalanced beauty-charmed baryons Ξbc+,0 \Xi_{bc}^{+,0} are of great significance to the development of heavy flavor physics. In this work, we study the inclusive weak-annihilation decays of Ξbc+,0\Xi_{bc}^{+,0} and their contributions to the Ξbc+,0\Xi_{bc}^{+,0} lifetimes. For the calculation of the inclusive Ξbc+,0β†’Xcs\Xi_{bc}^{+,0}\to X_{cs} decay width where XcsX_{cs} stands for the sum of the final states with charm number +1 and strange number -1, we work in the heavy diquark effective theory which provides us with a convenient technical tool to construct the operator product expansion. The Ξbc+,0\Xi_{bc}^{+,0} is considered to be a superposition of two states with one containing a spin-0 bcbc diquark and the other one containing a spin-1 bcbc diquark. It is found that both the Ξbc+,0\Xi_{bc}^{+,0} lifetimes and the Ξbc+,0β†’Xcs\Xi_{bc}^{+,0}\to X_{cs} branching ratios are very sensitive to the bcbc spin in Ξbc+,0\Xi_{bc}^{+,0}. As Ξbc+\Xi_{bc}^+ has a longer lifetime than Ξbc0\Xi_{bc}^{0} and bigger branching ratios of similar decay channels, the exclusive decays Ξbc+β†’D(βˆ—)+Ξ›\Xi_{bc}^+\to D^{(*)+}\Lambda, Ξbc+β†’Ξ›c+KΛ‰(βˆ—)0\Xi_{bc}^+\to \Lambda_c^+\bar{K}^{(*)0}, Ξbc+β†’D(βˆ—)+Kβˆ’p\Xi_{bc}^+\to D^{(*)+}K^-p, and Ξbc+β†’D0KΛ‰(βˆ—)0p\Xi_{bc}^+\to D^{0}\bar{K}^{(*)0}p are more promising for experimental searches of Ξbc+,0\Xi_{bc}^{+,0} at the LHC comparing with exclusive decay Ξbc0β†’D0pKβˆ’\Xi_{b c} ^{0} \to D^0pK^-.Comment: 7 pages, 4 figure

    Experimental investigations on core drilling by ultrasonic-vibration-assisted grinding for hard-to-machine materials - A review

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    Citation: Qin, N., Lei, J., & Pei, Z. J. (2016). Experimental investigations on core drilling by ultrasonic-vibration-assisted grinding for hard-to-machine materials - A review. International Journal of Manufacturing Research, 11(1), 28-52. doi:10.1504/IJMR.2016.076976Ultrasonic-vibration-assisted grinding (UVAG), a hybrid machining process combining material removal mechanisms of diamond grinding and ultrasonic machining, has been used to machine various hard-to-machine materials. Large amount of research work on UVAG has been carried out since it is invented. However there are few review papers to cover the current literature on UVAG. The emphasis of this literature review is the experimental investigations of the drilling process with ultrasonic vibration using a core drill with metal-bonded diamond abrasives. Experimental results are summarised and compared. The inconsistent results and their reasons are discussed. Furthermore, directions of future research on UVAG are also presented. Β© 2016 Inderscience Enterprises Ltd

    Optimization of microsatellite DNA Gelred fluorescence imaging technology

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    Gelred fluorescent dye has broader prospects of application in DNA experiment because of its high sensitivity, security and stability. In order to explore the best microsatellite DNA Gelred imaging technology, this study compared its dosage by using three methods; precasting gels method (PG), staining sample method (SS) and immersion gels method (IG). The results show that agarose gel electrophoresis (AGE) fluorescence imaging technology can use the first method (PG) and the concentration of Gelred was 1X, because of the best banding and easy operation. The polyacrylamide gel electrophoresis (PAGE) can use the third method (IG), for the advantages of clear and bright image, saving dye and easily redying to image. The orthogonal test showed that the parameters of IG method were: the concentration of Gelred was 2X, that of sodium chloride was 10% and immersion time was 40 min. The optimization of microsatellite DNA Gelred fluorescence imaging technology would lay a technical foundation in DNA banding related experiments.Key word: Agarose gel electrophoresis (AGE), polyacrylamide gel electrophoresis (PAGE), fluorescence imaging technology of Gelred, simple sequence repeat (SSR)
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