1,301 research outputs found

    On the Existence of Positive Solutions of Quasilinear Elliptic Boundary Value Problems

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    AbstractWe establish the existence of positive solutions to a class of quasilinear anisotropic problems which have either sublinear or superlinear nonlinearity. With a, b nonnegative constants and α, β positive constants, one example is If b−a<1 (sublinear case), then for each λ∈[0,∞), (1) has a solution. On the other hand, if b−a>1 (superlinear case), then there exists a λ*>0 such that for 0⩽λ<λ*, (1) has at least one solution, and for λ>λ* no solution exists

    Enhancement of electrical properties in Al-doped ZnO films by tuning dc bias voltage during radio frequency magnetron sputtering

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    Al-doped ZnO (AZO) thin films were deposited at room temperature on glass substrates by rf magnetron sputtering with simultaneous dc bias through an external inductor coil. The deposition rates of AZO films deposited using simultaneous rf and dc power along with an inductor coil were 20 higher than those deposited using only rf power. The effects of simultaneous rf and dc bias voltage during the deposition of AZO films were investigated in terms of their resistivity and compressive stress. It was observed that the AZO films deposited at 120 W rf power with 600 μH inductor coil exhibit the lowest resistivity of 6.71 à 10-4 Ïṡcm. © 2012 Elsevier B.V. All rights reserved

    Multiple-Domain Sentiment Classification for Cantonese Using a Combined Approach

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    In this study, we proposed a combined approach, which amalgamates machine learning and lexicon- based approaches for multiple-domain sentiment classification that supports Cantonese-based social media analysis. Our study contributes to the existing literature not only by investigating the effectiveness of the proposed combined approach for supporting social media analysis in the Cantonese context but also by verifying that the proposed method outperforms the baseline approaches, which are commonly used in the literature. We demonstrated that social media network-based classifiers can be general classifiers that support multiple-domain sentiment classification

    Comparison of computed tomographic findings in pulmonary mucormycosis and invasive pulmonary aspergillosis

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    AbstractBecause there are no available molecular markers for pulmonary mucormycosis (PM), which has low culture sensitivity, early diagnosis and treatment rely heavily on imaging modes such as computed tomography (CT). However, there are limited data comparing CT findings for PM with those for invasive pulmonary aspergillosis (IPA). Adult patients who met the modified criteria for proven and probable PM (over an 11-year period) and IPA (over a 6-year period, owing to the availability of the galactomannan assay) according to the modified European Organization for Research and Treatment of Cancer/Mycosis Study Group definitions were retrospectively enrolled. IPA cases were selected at a 1 : 4 (PM/IPA) ratio. Thoracic CT scans were reviewed by two experienced radiologists blinded to the patients' demographics and clinical outcomes. A total of 24 patients with PM, including 20 (83%) with proven PM and four (17%) with probable PM, and 96 patients with IPA, including 12 (13%) with proven IPA and 84 (87%) with probable IPA, were eventually analysed. The reverse halo sign was more common in patients with PM (54%) than in those with IPA (6%, p < 0.001), whereas some airway-invasive features, such as clusters of centrilobular nodules, peribronchial consolidations, and bronchial wall thickening, were more common in patients with IPA (IPA 52% vs. PM 29%, p 0.04; IPA 49% vs. PM 21%, p 0.01; IPA 34% vs. PM 4%, p 0.003, respectively). The reverse halo sign was more common, and airway-invasive features were less common, in patients with PM than in those with IPA. These findings may help physicians to initiate Zygomycetes-active antifungal treatment earlier

    Does the enhancement observed in γγDDˉ\gamma\gamma\to D\bar{D} contain two PP-wave higher charmonia?

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    Solved is a new puzzle raised by the observation of an enhancement structure Z(3930) in γγDDˉ\gamma\gamma\to D\bar{D}. If categorizing Z(3930) as χc2(2P)\chi_{c2}(2P) suggested by Belle and BaBar, we must explain why χc0(2P)\chi_{c0}(2P) dominantly decaying into DDˉD\bar{D} is missing in the DDˉD\bar{D} invariant mass spectrum. In this work, we propose that the Z(3930) enhancement structure may contain two PP-wave higher charmonia {χc0(2P)\chi_{c0}(2P)} and χc2(2P)\chi_{c2}(2P). We show that this assumption is supported by our analysis of the DDˉD\bar{D} invariant mass spectrum and cosθ\cos\theta^\ast distribution of γγDDˉ\gamma\gamma\to D\bar{D}. This observation would not only provide valuable information of two P-wave higher charmonia χc0(2P)\chi_{c0}(2P) and χc2(2P)\chi_{c2}(2P), but also serve as the crucial test of our novel proposal to the observed enhancement structure Z(3930), especially at the forthcoming BelleII and the approved SuperB.Comment: 5 pages, 2 tables, 3 figures. More contents and discussions adde

    Effect of RF power on the structural, optical and gas sensing properties of RF-​sputtered Al doped ZnO thin films

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    The effect of Radio Frequency (RF) power on the properties of magnetron sputtered Al doped ZnO thin films and the related sensor properties are investigated. A series of 2 wt​% Al doped ZnO; Zn0.98Al0.02O (AZO) thin films prepd. with magnetron sputtering at different RF powers, are examd. The structural results reveal a good adhesive nature of thin films with quartz substrates as well as increasing thickness of the films with increasing RF power. Besides, the increasing RF power is found to improve the crystallinity and grain growth as confirmed by X-​ray diffraction. On the other hand, the optical transmittance is significantly influenced by the RF power, where the transparency values achieved are higher than 82​% for all the AZO thin films and the estd. optical band gap energy is found to decrease with RF power due to an increase in the crystallite size as well as the film thickness. In addn., the defect induced luminescence at low temp. (77 K) and room temp. (300 K) was studied through photoluminescence spectroscopy, it is found that the defect d. of electronic states of the Al3+ ion increases with an increase of RF power due to the increase in the thickness of the film and the crystallite size. The gas sensing behavior of AZO films was studied for NO2 at 350 °C. The AZO film shows a good response towards NO2 gas and also a good relationship between the response and the NO2 concn., which is modeled using an empirical formula. The sensing mechanism of NO2 is discussed

    Perturbative Formulation and Non-adiabatic Corrections in Adiabatic Quantum Computing Schemes

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    Adiabatic limit is the presumption of the adiabatic geometric quantum computation and of the adiabatic quantum algorithm. But in reality, the variation speed of the Hamiltonian is finite. Here we develop a general formulation of adiabatic quantum computing, which accurately describes the evolution of the quantum state in a perturbative way, in which the adiabatic limit is the zeroth-order approximation. As an application of this formulation, non-adiabatic correction or error is estimated for several physical implementations of the adiabatic geometric gates. A quantum computing process consisting of many adiabatic gate operations is considered, for which the total non-adiabatic error is found to be about the sum of those of all the gates. This is a useful constraint on the computational power. The formalism is also briefly applied to the adiabatic quantum algorithm.Comment: 5 pages, revtex. some references adde

    Spin-dependent (magneto)transport through a ring due to spin-orbit interaction

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    Electron transport through a one-dimensional ring connected with two external leads, in the presence of spin-orbit interaction (SOI) of strength \alpha and a perpendicular magnetic field is studied. Applying Griffith's boundary conditions we derive analytic expressions for the reflection and transmission coefficients of the corresponding one-electron scattering problem. We generalize earlier conductance results by Nitta et al. [Appl. Phys. Lett. 75, 695 (1999)] and investigate the influence of \alpha, temperature, and a weak magnetic field on the conductance. Varying \alpha and temperature changes the position of the minima and maxima of the magnetic-field dependent conductance, and it may even convert a maximum into a minimum and vice versa.Comment: 19 pages, 9 figure

    Toroidal mode number estimation of the edge-localized modes using the KSTAR 3-D electron cyclotron emission imaging system

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    A new and more accurate technique is presented for determining the toroidal mode number n of edge-localized modes (ELMs) using two independent electron cyclotron emission imaging (ECEI) systems in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The technique involves the measurement of the poloidal spacing between adjacent ELM filaments, and of the pitch angle ?? O of filaments at the plasma outboard midplane. Equilibrium reconstruction verifies that ?? O is nearly constant and thus well-defined at the midplane edge. Estimates of n obtained using two ECEI systems agree well with n measured by the conventional technique employing an array of Mirnov coils.open3
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