10,125 research outputs found

    Optimal dynamic electricity consumption function estimation: an institutional experimental evidence from Guangzhou, China (1949-2016)

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    This research demonstrates from a dynamic optimal perspective that electricity consumption for a metropolitan area is a function of economic output, electricity consumption habits, and electricity demand management reform. The empirical results include: (1) an unidirectional Granger causality exists linking economic output to electricity consumption; (2) given electricity consumption habits under the context of the electricity demand management reform, an economic output increase of 1% results in the increase of electricity consumption by 0.22%, and (3), after demand management has been implemented, economic output continues to increase electricity consumption, but at a lower rate than prior to reform. These empirical results imply that the ‘conservation hypothesis’ is upheld over the long-run at the regional level in Guangzhou from 1949 to 2016

    η\eta production off the proton in a Regge-plus-chiral quark approach

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    A chiral constituent quark model approach, embodying s- and u-channel exchanges,complemented with a Reggeized treatment for t-channel is presented. A model is obtained allowing data for πpηn\pi^- p \to \eta n and γpηp\gamma p \to \eta p to be describe satisfactorily. For the latter reaction, recently released data by CLAS and CBELSA/TAPS Collaborations in the system total energy range 1.6W2.81.6 \lesssim W \lesssim 2.8 GeV are well reproduced due to the inclusion of Reggeized trajectories instead of simple ρ\rho and ω\omega poles. Contribution from "missing" resonances is found to be negligible in the considered processes.Comment: 23 pages.4 figures,4 tables, to appear in Phys.Rev.

    Modeling the tensile behavior of fiber bundles with irregular constituent fibers

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    In this paper, the effect of fiber dimensional irregularities on the tensile behavior of fiber bundles is modeled, using the finite element method (FEM). Fiber dimensional irregularities are simulated with sine waves of different magnitude. The specific stress-strain curves of fiber bundles and the constituent single fibers are obtained and compared. The results indicate that fiber diameter irregularity along fiber length has a significant effect on the tensile behavior of the fiber bundle. For a bundle of uniform fibers of different diameters, all constituent fibers will break simultaneously regardless of the fiber diameter. Similarly, if fibers within a bundle have the same pattern and level of diameter irregularity along fiber length, the fibers will break at the same time also regardless of the difference in average diameter of each fiber. In these cases, the specific stress and strain curve for the bundle overlaps with that of the constituent fibers. When the fiber bundle consists of single fibers with different levels of diameter irregularity, the specific stress-strain and load-elongation curves of the fiber bundle exhibit a stepped or &ldquo;ladder&rdquo; shape. The fiber with the highest irregularity breaks first, even when the thinnest section of the fiber is still coarser than the diameter of a very thin but uniform fiber in the bundle. This study suggests that fiber diameter irregularity along fiber length is a more important factor than the fiber diameter itself in determining the tensile behavior of a fiber bundle consisting of irregular fibers.<br /

    An improved study of the kappa resonance and the non-exotic ss wave πK\pi K scatterings up to s=2.1\sqrt{s}=2.1GeV of LASS data

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    We point out that the dispersion relation for the left hand cut integral presented in one of our previous paper (Nucl. Phys. {\bf A}733(2004)235) is actually free of subtraction constant, even for unequal mass elastic scatterings. A new fit to the LASS data~\cite{Aston} is performed and firm evidence for the existence of κ\kappa pole is found. The correct use of analyticity also put strong constraints on threshold parameters -- which are found to be in good agreement with those obtained from chiral theories. We also determined the pole parameters of K0(1430)K_0^*(1430) on the second sheet, and reconfirm the existence of K0(1950)K_0^*(1950) on the third sheet. We stress that the LASS data do not require them to have the twin pole structure of a typical Breit--Wigner resonance.Comment: 14 pages + 4 postscript figures; discussions largely expanded; references added; version to appear in NPA; title changed in the journa

    Effect of low-Raman window position on correlated photon-pair generation in a chalcogenide Ge11.5As24Se64.5 nanowire

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    We investigated correlated photon-pair generation via spontaneous four-wave mixing in an integrated chalcogenideGe11.5As24Se64.5photonicnanowire. The coincidence to accidental ratio, a key measurement for the quality of correlated photon-pair sources, was measured to be only 0.4 when the photon pairs were generated at 1.9 THz detuning from the pump frequency due to high spontaneous Raman noise in this regime. However, the existence of a characteristic low-Raman window at around 5.1 THz in this material's Raman spectrum and dispersion engineering of the nanowire allowed us to generate photon pairs with a coincidence to accidental ratio of 4.5, more than 10 times higher than the 1.9 THz case. Through comparing the results with those achieved in chalcogenide As2S3waveguides which also exhibit a low Raman-window but at a larger detuning of 7.4 THz, we find that the position of the characteristic low-Raman window plays an important role on reducing spontaneous Raman noise because the phonon population is higher at smaller detuning. Therefore the ultimate solution for Raman noise reduction in Ge11.5As24Se64.5 is to generate photon pairs outside the Raman gain band at more than 10 THz detuning

    Carpet cloaking on a dielectric half-space

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    Carpet cloaking is proposed to hide an object on a dielectric half-space from electromagnetic (EM) detection. A two-dimensional conformal transformation specified by an analytic function is utilized for the design. Only one nonsingular material parameter distribution suffices for the characterization. The cloaking cover situates on the dielectric half-space, and consists of a lossless upper part for EM wave redirection and an absorbing bottom layer for inducing correct reflection coefficient and absorbing transmission. Numerical simulations with Gaussian beam incidence are performed for verification.Comment: 6 pages, 3 figure

    Dissociation of H2 molecule on the {\beta}-Ga2O3 (100)B surface: The critical role of oxygen vacancy

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    We systematically study the dissociation of H2 molecules on the {\beta}-Ga2O3 (100)B surface, with the influences of surface oxygen vacancy being considered. After introducing the surface oxygen vacancy, the nearest topmost O(I) atom becomes very active, and hydrogen molecules become much easier to dissociate.Comment: 6 pages, 5 figure

    New Topflavor Models with Seesaw Mechanism

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    New class of models are constructed in which the third family quarks, but not leptons, experience a new SU(2) or U(1) gauge force. Anomaly cancellation enforces the introduction of spectator quarks so that the top and bottom masses are naturally generated via a seesaw mechanism. We find the new contributions to the (S,T,U) parameters and Zbb vertex to be generically small. We further analyze how the reasonable flavor mixing pattern can be generated to ensure the top-seesaw mechanism and sufficiently suppress the flavor-changing effects for light quarks. Collider signatures for the light Higgs boson and top quark are also discussed.Comment: To match the version in Rapid Communication of PRD, RevTex 5p

    QCD Corrections to Scalar Production via Heavy Quark Fusion at Hadron Colliders

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    We recently proposed that, due to the top-quark-mass enhanced Yukawa coupling, the s-channel production of a charged scalar or pseudo-scalar from heavy quark fusion can be an important new mechanism for discovering non-standard spin-0 particles. In this work, we present the complete O(alpha_s) QCD corrections to this s-channel production process at hadron colliders, including the results of QCD resummation over multiple soft-gluon emission. The systematic QCD-improved production and decay rates at the FermiLab Tevatron and the CERN LHC are given for the charged top-pions in the topcolor models and for the charged Higgs bosons in the generic two Higgs doublet model. The direct extension to the production of the neutral (pseudo-)scalars via bb\bar fusion is studied in the minimal supersymmetric standard model (MSSM) with large tan(beta), and in the topcolor model with large bottom Yukawa coupling.Comment: Version to be published in Phys.Rev.D. Discussion on Rb added plus minor improvements. Conclusions not changed. Latex2e, 40 pages, 16 figure
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