223 research outputs found

    Architecture Layer Based Grid Computing Security Study

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    With increasing grid computing application in more and more industries and sectors, grid security has grown into the most critical as well as important aspect in overall application architecture. This article, from architecture layer security dimension, studies security issue in grid computing environments, indicating architecture layer based security solutions in current grid computing and proposing grid security recommendations as well, which will contribute to further defining and analyzing security strategy in grid computing and function as a guideline to the development of grid computing technology. Keywords: grid security infrastructure; security strategy; grid computin

    PKI and Its Applications in E-Commerce in China

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    PKI system supports user authentication, message transmission, data integrity, message storage confidentiality, and the non-repudiation of operation. PKI can completely address e-commerce security requirements and PKI technology has been applied successfully in e-commerce as well. This article studies the system compositions of e-commerce, briefly analyzes e-commerce’s applications in various countries, and highlights PKI and its applications in e-commerce in China. Keywords: Public Key Infrastructure; E-commerce; applicatio

    Time Evolution of Entanglement Entropy in Quenched Holographic Superconductors

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    We investigate the dynamical evolution of entanglement entropy in a holographic superconductor model by quenching the source term of the dual charged scalar operator. By access to the full background geometry, the holographic entanglement entropy is calculated for a strip geometry at the AdS boundary. It is found that the entanglement entropy exhibits a robust non-monotonic behaviour in time, independent of the strength of Gaussian quench and the size of the strip: it first displays a small dip, then grows linearly, and finally saturates. In particular, the linear growth velocity of the entanglement entropy has an upper bound for strip with large width; The equilibrium value of the non-local probe at late time shows a power law scaling behaviour with respect to the quench strength; Moreover, the entanglement entropy can uncover the dynamical transition at certain critical quench strength which happens to coincide with the one obtained form the dynamical evolution of scalar order parameter.Comment: 19 pages; 7 figures; compatible with JHEP versio

    Quantum theory of light diffraction

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    At present, the theory of light diffraction only has the simple wave-optical approach. In this paper, we study light diffraction with the approach of relativistic quantum theory. We find that the slit length, slit width, slit thickness and wave-length of light have affected to the diffraction intensity and form of diffraction pattern. However, the effect of slit thickness on the diffraction pattern can not be explained by wave-optical approach, and it can be explained in quantum theory. We compare the theoretical results with single and multiple slits experiment data, and find the theoretical results are accordance with the experiment data. Otherwise, we give some theory prediction. We think all the new prediction will be tested by the light diffraction experiment.Comment: 10 page

    Ligustrazine Injection for Chronic Pulmonary Heart Disease: A Systematic Review and Meta-Analysis

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    Objective. This study was intended to evaluate the efficacy and safety of ligustrazine injection for chronic pulmonary heart disease (CPHD). Method. Randomized controlled trials (RCTs) of clinical therapeutic studies on CPHD when using ligustrazine injection were included. Searches were applied to the following electronic databases: the PubMed, the Cochrane Library, EMBASE, CBM, and AMED. No language restriction was used. All trials included were analyzed according to the criteria of the Cochrane Handbook. Review Manager 5.0 software was used for data analysis. Result. 34 RCTs with low methodological quality were included. Compared to conventional medicine treatment alone, ligustrazine injection plus conventional medicine treatment showed improvement in New York Heart Association classification of clinical status (Odds ratio 0.22; 95% CI 0.17 to 0.28) and depression of pulmonary artery hypertension (weighted mean difference −4.77; 95% CI −5.85 to −3.68). Three studies had reported adverse events. No serious adverse effects were reported. Conclusion. While there is some evidence that suggests potential effectiveness of ligustrazine injection for CPHD, the results were limited by the methodological flaws of the studies. High quality studies are needed to provide clear evidence for the future use of ligustrazine injection

    Quantum theory of electronic double-slit diffraction

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    The phenomena of electron, neutron, atomic and molecular diffraction have been studied by many experiments, and these experiments are explained by some theoretical works. In this paper, we study electronic double-slit diffraction with quantum mechanical approach. We can obtain the results: (1) When the slit width aa is in the range of 3λ50λ3\lambda\sim 50\lambda we can obtain the obvious diffraction patterns. (2) when the ratio of d+aa=n(n=1,2,3,)\frac{d+a}{a}=n (n=1, 2, 3,\cdot\cdot\cdot), order 2n,3n,4n,2n, 3n, 4n,\cdot\cdot\cdot are missing in diffraction pattern. (3)When the ratio of d+aan(n=1,2,3,)\frac{d+a}{a}\neq n (n=1, 2, 3,\cdot\cdot\cdot), there isn't missing order in diffraction pattern. (4) We also find a new quantum mechanics effect that the slit thickness cc has a large affect to the electronic diffraction patterns. We think all the predictions in our work can be tested by the electronic double-slit diffraction experiment.Comment: 9pages, 14figure

    Function Photonic Crystals

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    In the paper, we present a new kind of function photonic crystals, which refractive index is a function of space position. Unlike conventional PCs, which structure grow from two materials, A and B, with different dielectric constants ϵA\epsilon_{A} and ϵB\epsilon_{B}. By Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we study the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals. By choosing various refractive index distribution function n(z)n(z), we can obtain more width or more narrow band gap structure than conventional photonic crystals.Comment: 15 pages, 8 figures. arXiv admin note: text overlap with arXiv:1001.3793 by other authors; and text overlap with arXiv:1003.3524, arXiv:physics/0104088 by other authors without attributio
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