223 research outputs found
Architecture Layer Based Grid Computing Security Study
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
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
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
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
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
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 is in the range of we can obtain the obvious
diffraction patterns. (2) when the ratio of , order are missing in
diffraction pattern. (3)When the ratio of , there isn't missing order in diffraction pattern. (4) We
also find a new quantum mechanics effect that the slit thickness 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
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Electrostatic force driven helium insertion into ammonia and water crystals under pressure
Abstract: Helium, ammonia and ice are among the major components of giant gas planets, and predictions of their chemical structures are therefore crucial in predicting planetary dynamics. Here we demonstrate a strong driving force originating from the alternation of the electrostatic interactions for helium to react with crystals of polar molecules such as ammonia and ice. We show that ammonia and helium can form thermodynamically stable compounds above 45 GPa, while ice and helium can form thermodynamically stable compounds above 300 GPa. The changes in the electrostatic interactions provide the driving force for helium insertion under high pressure, but the mechanism is very different to those that occur in ammonia and ice. This work extends the reactivity of helium into new types of compounds and demonstrates the richness of the chemistry of this most stable element in the periodic table
Function Photonic Crystals
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 and . 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 , 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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