2,666 research outputs found

    Distribution logistics of online fashion retail business in China: A case study of VANCL

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    The rapid development of information technologies brings more convenience to people. Information technologies, especially the Internet, not only save time for consumers and companies but also provide them with more channels and opportunities for interaction and conducting transactions. One business revolution brought by Internet is online shopping – shopping and buying products in online stores or websites. Nowadays, online shopping has become a new consuming model for consumers both in China and around the world. This paper analyses online shopping for fashion in China and investigates the impact of online shopping on logistics industry using the case of “VANCL”

    Charmless Two-body Baryonic B Decays

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    We study charmless two-body baryonic B decays in a diagramatic approach. Relations on decay amplitudes are obtained. In general there are more than one tree and more than one penguin amplitudes. The number of independent amplitudes can be reduced in the large m_B limit. It leads to more predictive results. Some prominent modes for experimental searches are pointed out.Comment: 15 pages, 2 figures. To appear in Phys. Rev.

    Charmless Exclusive Baryonic B Decays

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    We present a systematical study of two-body and three-body charmless baryonic B decays. Branching ratios for two-body modes are in general very small, typically less than 10610^{-6}, except that \B(B^-\to p \bar\Delta^{--})\sim 1\times 10^{-6}. In general, BˉNΔˉ>BˉNNˉ\bar B\to N\bar\Delta>\bar B\to N\bar N due to the large coupling constant for ΣbBΔ\Sigma_b\to B\Delta. For three-body modes we focus on octet baryon final states. The leading three-dominated modes are Bˉ0pnˉπ(ρ),npˉπ+(ρ+)\bar B^0\to p\bar n\pi^-(\rho^-), n\bar p\pi^+(\rho^+) with a branching ratio of order 3×1063\times 10^{-6} for Bˉ0pnˉπ\bar B^0\to p\bar n\pi^- and 8×1068\times 10^{-6} for Bˉ0pnˉρ\bar B^0\to p\bar n\rho^-. The penguin-dominated decays with strangeness in the meson, e.g., BppˉK()B^-\to p\bar p K^{-(*)} and Bˉ0pnˉK(),nnˉKˉ0()\bar B^0\to p\bar n K^{-(*)}, n\bar n \bar K^{0(*)}, have appreciable rates and the NNˉN\bar N mass spectrum peaks at low mass. The penguin-dominated modes containing a strange baryon, e.g., Bˉ0Σ0pˉπ+,Σnˉπ+\bar B^0\to \Sigma^0\bar p\pi^+, \Sigma^-\bar n\pi^+, have branching ratios of order (14)×106(1\sim 4)\times 10^{-6}. In contrast, the decay rate of Bˉ0Λpˉπ+\bar B^0\to\Lambda\bar p\pi^+ is smaller. We explain why some of charmless three-body final states in which baryon-antibaryon pair production is accompanied by a meson have a larger rate than their two-body counterparts: either the pole diagrams for the former have an anti-triplet bottom baryon intermediate state, which has a large coupling to the BB meson and the nucleon, or they are dominated by the factorizable external WW-emission process.Comment: 46 pages and 3 figures, to appear in Phys. Rev. D. Major changes are: (i) Calculations of two-body baryonic B decays involving a Delta resonance are modified, and (ii) Penguin-dominated modes B-> Sigma+N(bar)+p are discusse

    The Schrodinger equation with Hulthen potential plus ring-shaped potential

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    We present the solutions of the Schro¨\ddot{o}dinger equation with the Hultheˊ\acute{e}n potential plus ring-shape potential for 0\ell\neq 0 states within the framework of an exponential approximation of the centrifugal potential.Solutions to the corresponding angular and radial equations are obtained in terms of special functions using the conventional Nikiforov-Uvarov method. The normalization constant for the Hultheˊ\acute{e}n potential is also computed.Comment: Typed with LateX,12 Pages, Typos correcte

    Synthesis and antibacterial effects of cobalt–cellulose magnetic nanocomposites

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    © The Royal Society of Chemistry. Green synthesis is employed to prepare cobalt/cellulose nanocomposites with cubic (α-cobalt) cobalt as a main component with antibacterial and magnetic properties. An in situ reduction of aqueous solutions of cobalt ions on a model cellulose substrate surface using hydrogen gas affords spherical, cellulose-stabilised cobalt nanoclusters with magnetic properties and an average diameter of 7 nm that are distributed evenly over the surface of the cellulose fibres. These cobalt/cellulose nanocomposites exhibit good antibacterial action against opportunistic pathogens both Gram-positive (S. aureus) and Gram-negative (E. coli, A. baumannii and P. aeruginosa), with zones of inhibition up to 15 mm, thereby encouraging the deployment of these advanced materials for the treatment of wastewater or within medical dressings. This method of preparation is compared with the analogous in situ reduction of cobalt ions on a cellulose surface using sodium borohydride as reducing agent

    Anomalous behavior of the Debye temperature in Fe-rich Fe-Cr alloys

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    Debye temperature, ΘD\Theta_D, of Fe-rich Fe100x_{100-x}Crx_x disordered alloys with 0x22.30\le x \le 22.3 was determined from the temperature dependence of the central shift of M\"ossbauer spectra recorded in the temperature range of 60 -- 300 K. Its compositional dependence shows a maximum at x5x \approx 5 with a relative increase of 30\sim 30% compared to a pure iron. The composition at which the effect occurs correlates well with that at which several other quantities, e. g. the Curie temperature and the spin-wave stiffness coefficient, D0D_0, show their maxima, but the enhancement of ΘD\Theta_D is significantly greater and comparable with the enhancement of the hyperfine field (spin-density of itinerant ss-like electrons) in the studied system. The results suggest that the electron-phonon interaction is important in this alloy system

    Approximate relativistic bound state solutions of the Tietz-Hua rotating oscillator for any -state

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    Approximate analytic solutions of the Dirac equation with Tietz-Hua (TH) potential are obtained for arbitrary spin-orbit quantum number using the Pekeris approximation scheme to deal with the spin-orbit coupling terms In the presence of exact spin and pseudo-spin (pspin) symmetric limitation, the bound state energy eigenvalues and associated two-component wave functions of the Dirac particle moving in the field of attractive and repulsive TH potential are obtained using the parametric generalization of the Nikiforov-Uvarov (NU) method. The cases of the Morse potential, the generalized Morse potential and non-relativistic limits are studied.Comment: 19 pages; 7 figures; Few-Body Systems (2012) (at press

    Spontaneous breaking of Lorentz invariance, black holes and perpetuum mobile of the 2nd kind

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    We study the effect of spontaneous breaking of Lorentz invariance on black hole thermodynamics. We consider a scenario where Lorentz symmetry breaking manifests itself by the difference of maximal velocities attainable by particles of different species in a preferred reference frame. The Lorentz breaking sector is represented by the ghost condensate. We find that the notions of black hole entropy and temperature loose their universal meaning. In particular, the standard derivation of the Hawking radiation yields that a black hole does emit thermal radiation in any given particle species, but with temperature depending on the maximal attainable velocity of this species. We demonstrate that this property implies violation of the second law of thermodynamics, and hence, allows construction of a perpetuum mobile of the 2nd kind. We discuss possible interpretation of these results.Comment: 13 pages; references adde
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