4,551 research outputs found

    Closed-loop supply chain coordination based on recyclers\u27 competition model

    Get PDF
    In a closed-loop supply chain led by manufacturing enterprises, there are often two or more recyclers that are very competitive among each other. The manufacturer may also provide many recycling contracts in order to identify recyclers’ private information. This paper examines a closed-loop supply chain consisting of a manufacturer at the core of the supply chain and two competing recyclers. In order to strike a balance between its own interest and overall interest manufacturer provides two different recycling contracts: price contract and quantity contract. Two situations have been analyzed in this paper: the first in which only advantage recycler adopts quantity contract and the second in which both recyclers adopt quantity contract. A numerical simulation has been carried out according to some current data of an enterprise. In case in which the advantage recycler adopts quantity contract and the inferior recycler adopts price contract, the closed-loop supply chain has reached its equilibrium and the interests of all parties have been balanced

    One-dimensional quantum channel in a graphene line defect

    Full text link
    Using a tight-binding model, we study a line defect in graphene where a bulk energy gap is opened by sublattice symmetry breaking. It is found that sublattice symmetry breaking may induce many configurations that correspond to different band spectra. In particular, a gapless state is observed for a configuration which hold a mirror symmetry with respect to the line defect. We find that this gapless state originates from the line defect and is independent of the width of the graphene ribbon, the location of the line defect, and the potentials in the edges of the ribbon. In particular, the gapless state can be controlled by the gate voltage embedded below the line defect. Finally, this result is supported with conductance calculations. This study shows how a quantum channel could be constructed using a line defect, and how the quantum channel can be controlled by tuning the gate voltage embedded below the line defect.Comment: 8 pages, 10 figure

    Disorder and metal-insulator transitions in Weyl semimetals

    Full text link
    The Weyl semimetal (WSM) is a newly proposed quantum state of matter. It has Weyl nodes in bulk excitations and Fermi arcs surface states. We study the effects of disorder and localization in WSMs and find three exotic phase transitions. (I) Two Weyl nodes near the Brillouin zone boundary can be annihilated pairwise by disorder scattering, resulting in the opening of a topologically nontrivial gap and a transition from a WSM to a three-dimensional (3D) quantum anomalous Hall state. (II) When the two Weyl nodes are well separated in momentum space, the emergent bulk extended states can give rise to a direct transition from a WSM to a 3D diffusive anomalous Hall metal. (III) Two Weyl nodes can emerge near the zone center when an insulating gap closes with increasing disorder, enabling a direct transition from a normal band insulator to a WSM. We determine the phase diagram by numerically computing the localization length and the Hall conductivity, and propose that the exotic phase transitions can be realized on a photonic lattice.Comment: 7 pages with appendix, 6 figure

    The swap operation in the two-qubit Heisenberg XXZ model-effects of anisotropy and magnetic field

    Full text link
    In this paper we study the swap operation in a two-qubit anisotropic XXZ model in the presence of an inhomogeneous magnetic field. We establish the range of anisotropic parameter within which the swap operation is feasible. The swap errors caused by the inhomogeneous field are evaluated

    Disorder induced field effect transistor in bilayer and trilayer graphene

    Full text link
    We propose use of disorder to produce a field effect transistor (FET) in biased bilayer and trilayer graphene. Modulation of the bias voltage can produce large variations in the conductance when the disorder's effects are confined to only one of the graphene layers. This effect is based on the bias voltage's ability to select which of the graphene layers carries current, and is not tied to the presence of a gap in the density of states. In particular, we demonstrate this effect in models of gapless ABA-stacked trilayer graphene, gapped ABC-stacked trilayer graphene, and gapped bilayer graphene.Comment: 21 pages, 7 figure

    Application of Metabolomics in Traditional Chinese Medicine Differentiation of Deficiency and Excess Syndromes in Patients with Diabetes Mellitus

    Get PDF
    Metabolic profiling is widely used as a probe in diagnosing diseases. In this study, the metabolic profiling of urinary carbohydrates was investigated using gas chromatography/mass spectrometry (GC/MS) and multivariate statistical analysis. The kernel-based orthogonal projections to latent structures (K-OPLS) model were established and validated to distinguish between subjects with and without diabetes mellitus (DM). The model was combined with subwindow permutation analysis (SPA) in order to extract novel biomarker information. Furthermore, the K-OPLS model visually represented the alterations in urinary carbohydrate profiles of excess and deficiency syndromes in patients with diabetes. The combination of GC/MS and K-OPLS/SPA analysis allowed the urinary carbohydrate metabolic characterization of DM patients with different traditional Chinese medicine (TCM) syndromes, including biomarkers different from non-DM patients. The method presented in this study might be a complement or an alternative to TCM syndrome research

    The Effects Of Surface Characteristics On Liquid Behaviors Of Fins During Frosting And Defrosting Processes

    Get PDF
    Liquid behaviors, including droplet condensation and frost melt water retention, of fins during frosting and defrosting processes on three aluminum fins with different surface characteristics under winter operating conditions of an air source heat pump were investigated. The effects of the surface characteristics, including the contact angle and the contact angle hysteresis, were analyzed. Droplets were observed firstly on a bare fin and on a super hydrophobic fin last, and exhibited different sizes and shapes under the effects of the surface characteristics. The droplet distribution was sparser on the super hydrophobic fin than on the other two fins because of the consolidation, rolling and departure of droplets. There was an obvious difference on frost melt water retention between the three fins. Residual water formed a thin water film on a hydrophilic fin, while only a few spherical droplets of small sizes stayed on the super hydrophobic fin. The effects of the surface characteristics were found to be significant on the mass of residual water, which decreased by 79.82% on the super hydrophobic fin compared with that on the hydrophilic fin. Finally, the effects of the contact angle and the contact angle hysteresis on frost melt water retention were quantitatively analyzed. Results indicate that the super hydrophobic fin can restrain the droplet condensation and frost melt water retention

    Effects of ZbZ_b states and bottom meson loops on Υ(4S)Υ(1S,2S)π+π\Upsilon(4S) \to \Upsilon(1S,2S) \pi^+\pi^- transitions

    Full text link
    We study the dipion transitions Υ(4S)Υ(nS)π+π\Upsilon(4S) \rightarrow \Upsilon(nS) \pi^+\pi^- (n=1,2)(n=1,2). In particular, we consider the effects of the two intermediate bottomoniumlike exotic states Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650) as well as bottom meson loops. The strong pion-pion final-state interactions, especially including channel coupling to KKˉK\bar{K} in the SS-wave, are taken into account model-independently by using dispersion theory. Based on a nonrelativistic effective field theory we find that the contribution from the bottom meson loops is comparable to those from the chiral contact terms and the ZbZ_b-exchange terms. For the Υ(4S)Υ(2S)π+π\Upsilon(4S) \rightarrow \Upsilon(2S) \pi^+\pi^- decay, the result shows that including the effects of the ZbZ_b-exchange and the bottom meson loops can naturally reproduce the two-hump behavior of the ππ\pi\pi mass spectra. Future angular distribution data are decisive for the identification of different production mechanisms. For the Υ(4S)Υ(1S)π+π\Upsilon(4S) \rightarrow \Upsilon(1S) \pi^+\pi^- decay, we show that there is a narrow dip around 1 GeV in the ππ\pi\pi invariant mass distribution, caused by the final-state interactions. The distribution is clearly different from that in similar transitions from lower Υ\Upsilon states, and needs to be verified by future data with high statistics. Also we predict the decay width and the dikaon mass distribution of the Υ(4S)Υ(1S)K+K\Upsilon(4S) \rightarrow \Upsilon(1S) K^+ K^- process.Comment: 25 pages, 8 figures, predictions of the decay width and the dikaon mass distribution of the Υ(4S)Υ(1S)K+K\Upsilon(4S) \rightarrow \Upsilon(1S) K^+ K^- process added, more discussions adde
    corecore