4,644 research outputs found

    The classification of all single travelling wave solutions to Calogero-Degasperis-Focas equation

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    Under the travelling wave transformation, Calogero-Degasperis-Focas equation was reduced to an ordinary differential equation. Using a symmetry group of one-parameter, this ODE was reduced to a second order linear inhomogeneous ODE. Furthermore, we applied the change of the variable and complete discrimination system for polynomial to solve the corresponding integrals and obtained the classification of all single travelling wave solutions to Calogero-Degasperis-Focas equation.Comment: 9 page

    Nonadiabatic quantum pumping in mesoscopic nanostructures

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    We consider a nonadiabatic quantum pumping phenomena in a ballistic narrow constriction. The pumping is induced by a potential that has both spatial and temporal periodicity characterized by KK and Ω\Omega. In the zero frequency (Ω=0\Omega=0) limit, the transmission through narrow constriction exhibits valley structures due to the opening up of energy gaps in the pumping region -- a consequence of the KK periodicity. These valley structures remain robust in the regime of finite Ω\Omega, while their energies of occurrence are shifted by about Ω/2\hbar\Omega/2. The direction of these energy shifts depend on the directions of both the phase-velocity of the pumping potential and the transmitting electrons. This frequency dependent feature of the valley structures gives rise to both the asymmetry in the transmission coefficients and the pumping current. An experimental setup is suggested for a possible observation of our nonadiabatic quantum pumping findings.Comment: 4 pages, 2 figure

    O(αs) O(\alpha_s) corrections to polarized top decay into a charged Higgs t()H++b t(\uparrow) \to H^+ + b

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    We calculate the O(αs) O(\alpha_s) radiative corrections to polarized top quark decay into a charged Higgs boson and a massive bottom quark in two variants of the two-Higgs-doublet model. The radiative corrections to the polarization asymmetry of the decay may become as large as 25 25 % . We provide analytical formulae for the unpolarized and polarized rates for mb0 m_b \neq 0 and for mb=0 m_b = 0 . For mb=0 m_b = 0 our closed-form expressions for the unpolarized and polarized rates become rather compact.Comment: 24 pages, 5 figures in the text, content modified, comments added, appendices added, references updated, replaced with published versio

    Anomalous oxidation of Fe-Si alloys under a low oxygen pressure at 800 °C

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    The authors acknowledge financial support by NSFC of China under the research projects (Nos. 50971129 and 51371183).Abstract The oxidation of three Fe-xSi alloys (x = 5, 9, 13 at.%) under 10−20 atm O2 at 800 °C formed in all cases SiO2 layers. For Fe-5Si this layer broke down and healed up periodically forming an anomalous internal oxidation zone with spherical and net-shaped SiO2 particles. The SiO2 layer formed on the other two alloys spalled off due to the growth and thermal stress accumulated. The critical silicon content needed for its external oxidation on Fe-Si alloys calculated according to an extension of Wagner's theory under the present experimental conditions is significantly smaller than the experimental results.PostprintPeer reviewe

    PHP61 The Financial Impacts of Pharmacist Intervention in Inpatient Department of a Local Hospital in Taiwan

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    Morphometric analysis of S. mortenseni. (DOC 44 kb

    Effect of boundaries on the force distributions in granular media

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    The effect of boundaries on the force distributions in granular media is illustrated by simulations of 2D packings of frictionless, Hertzian spheres. To elucidate discrepancies between experimental observations and theoretical predictions, we distinguish between the weight distribution {\cal P} (w) measured in experiments and analyzed in the q-model, and the distribution of interparticle forces P(f). The latter one is robust, while {\cal P}(w) can be obtained once the local packing geometry and P(f) are known. By manipulating the (boundary) geometry, we show that {\cal P}(w) can be varied drastically.Comment: 4 pages, 4 figure

    Is DsJ+(2632)D^{+}_{sJ}(2632) the first radial excitation of Ds(2112)D_{s}^{*}(2112)?

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    We present a quantitative analysis of the DsJ+(2632)D^{+}_{sJ}(2632) observed by SELEX mainly focusing on the assumption that DsJ+(2632)D^{+}_{sJ}(2632) is the first radial excitation of the 11^{-} ground state Ds(2112)D^{*}_{s}(2112). By solving the instantaneous Bethe-Salpeter equation, we obtain the mass 2658±152658\pm 15 MeV for the first excited state, which is about 26 MeV heavier than the experimental value 2632±1.72632\pm 1.7 MeV. By means of PCAC and low-energy theorem we calculate the transition matrix elements and obtain the decay widths: Γ(DsJ+Ds+η)=4.07±0.34\Gamma(D^{+}_{sJ}\to D^{+}_s\eta)=4.07\pm 0.34 MeV, Γ(DsJ+D0K+)Γ(Γ(DsJ+D+K0)=8.9±1.2\Gamma(D^{+}_{sJ}\to D^{0}K^{+}) \simeq \Gamma(\Gamma(D^{+}_{sJ}\to D^{+}K^{0})=8.9\pm 1.2 MeV, and the ratio Γ(DsJ+D0K+)/Γ(DsJ+Ds+η)=2.2±0.2\Gamma(D^{+}_{sJ}\to D^{0}K^{+})/\Gamma(D^{+}_{sJ}\to D^{+}_{s}\eta)=2.2\pm 0.2 as well. This ratio is quite different from the SELEX data 0.14±0.060.14\pm 0.06. The summed decay width of those three channels is approximately 21.7 MeV, already larger than the observed bound for the full width (17\leq 17 MeV). Furthermore, assuming DsJ+(2632)D_{sJ}^+(2632) is 11^{-} state, we also explore the possibility of SDS-D wave mixing to explain the SELEX observation. Based on our analysis, we suspect that it is too early to conclude that DsJ+(2632)D^{+}_{sJ}(2632) is the first radial excitation of the 11^{-} ground state Ds(2112)D^{*}_{s}(2112). More precise measurements of the relative ratios and the total decay width are urgently required especially for SDS-D wave mixing.Comment: 12 pages, 8 figure

    A Multiple Commutator Formula for the Sum of Feynman Diagrams

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    In the presence of a large parameter, such as mass or energy, leading behavior of individual Feynman diagrams often get cancelled in the sum. This is known to happen in large-NcN_c QCD in the presence of a baryon, and also in the case of high-energy electron-electron as well as quark-quark scatterings. We present an exact combinatorial formula, involving multiple commutators of the vertices, which can be used to compute such cancellations. It is a non-abelian generalization of the eikonal formula, and will be applied in subsequent publications to study the consistency of large-NcN_c QCD involving baryons, as well as high-energy quark-quark scattering in ordinary QCD.Comment: uu-encoded latex file with two postscript figure

    Long-term trends in tropical cyclone tracks around Korea and Japan in late summer and early fall

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    This study investigates long-term trends in tropical cyclones (TCs) over the extratropical western North Pacific (WNP) over a period of 35 years (1982-2016). The area analyzed extended across 30-45 degrees N and 120-150 degrees E, including the regions of Korea and Japan that were seriously affected by TCs. The northward migration of TCs over the WNP to the mid-latitudes showed a sharp increase in early fall. In addition, the duration of TCs over the WNP that migrated northwards showed an increase, specifically in early to mid-September. Therefore, more recently, TC tracks have been observed to significantly extend into the mid-latitudes. The recent northward extension of TC tracks over the WNP in early fall was observed to be associated with changes in environmental conditions that were favorable for TC activities, including an increase in sea surface temperature (SST), decrease in vertical wind shear, expansion of subtropical highs, strong easterly steering winds, and an increase in relative vorticity. In contrast, northward migrations of TCs to Korea and Japan showed a decline in late August, because of the presence of unfavorable environmental conditions for TC activities. These changes in environmental conditions, such as SST and vertical wind shear, can be partially associated with the Pacific decadal oscillation

    Leaf segmentation and tracking using probabilistic parametric active contours

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    Active contours or snakes are widely used for segmentation and tracking. These techniques require the minimization of an energy function, which is generally a linear combination of a data fit term and a regularization term. This energy function can be adjusted to exploit the intrinsic object and image features. This can be done by changing the weighting parameters of the data fit and regularization term. There is, however, no rule to set these parameters optimally for a given application. This results in trial and error parameter estimation. In this paper, we propose a new active contour framework defined using probability theory. With this new technique there is no need for ad hoc parameter setting, since it uses probability distributions, which can be learned from a given training dataset
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