12,054 research outputs found

    Relativistic effects on the observed AGN luminosity distribution

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    Recently Zhang (2005) has proposed a model to account for the well established effect that the fraction of type-II AGNs is anti-correlated with the observed X-ray luminosity; the model consists of an X-ray emitting accretion disk coaligned to the dusty torus within the standard AGN unification model. In this paper the model is refined by including relativistic effects of the observed X-ray radiations from the vicinity of the supermassive black hole in an AGN. The relativistic corrections improve the combined fitting results of the observed luminosity distribution and the type-II AGN fraction, though the improvement is not significant. The type-II AGN fraction prefers non- or mildly spinning black hole cases and rules out the extremely spinning case.Comment: 9 pages, 4 figures, accepted for publication in PAS

    GRO J1655-40: from ASCA and XMM-Newton Observations

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    We have analysed four ASCA observations (1994--1995, 1996--1997) and three XMM-Newton observations (2005) of this source, in all of which the source is in high/soft state. We modeled the continuum spectra with relativistic disk model kerrbb, estimated the spin of the central black hole, and constrained the spectral hardening factor f_col and the distance. If kerrbb model applies, for normally used value of f_col, the distance cannot be very small, and f_col changes with observations.Comment: 2 pages, 1 figure, Conference proceedings to appear in "The Central Engine of Active Galactic Nuclei", ed. L. C. Ho and J.-M. Wang (San Francisco: ASP

    The Influence of Augmented Reality Technology on the Learning Interest, Achievement of Learning Goals and Cognitive Load of Middle School Students

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    In order to test the influence of augmented reality technology on the learning interest achievement of learning goals and cognitive load the instruction of topographic map was taken as an example for experimental study This paper selected 427 students from 8 classes of Grade one who all come from Zhantan Middle School in Xindu District of Chengdu as experimental samples set two classes with similar level in learning as one group the one is the experimental class and the other is the control class and formed 4 groups in total The experimental classes adopted AR three-dimensional videos as teaching aids to give new lessons and the control classes adopted traditional two- dimensional videos and then the students learning interest level achievement of learning goals and cognitive load were measured The results showed that the application of AR technology in teaching could improve students learning interest and achievement of learning goals but had no effect on reducing cognitive loa

    3-[(Cyclo­hexyl­idene)amino]-1-(4-methyl­phen­yl)thio­urea

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    In the title compound, C14H19N3S, the cyclo­hexane ring has a chair conformation. The almost planar amino­thio­urea unit (r.m.s. deviation = 0.0062 Å) is aligned at a dihedral angle of 45.23 (8)° with respect to the benzene ring. Inter­molecular N—H⋯N and N—H⋯S hydrogen bonding stabilizes the crystal structure

    The sunflower moth, Homoeosoma nebulella (Denis et Schiffermüller ) (Lepidoptera: Pyralidae): outbreaks and pest management in Linhe, Inner Mongolia 2007–2008

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    Sunflowermoth Homoeosoma nebulella is the most common pest of sunflowers (Helianthus annuus L.) in China. A large outbreak involving H. nebulella was discovered in Linhe of the Mongolia Autonomous Region in 2007. Different issues related to pest management were investigated in 2007–2008. Irrigation for overwintering could promote pest outbreak in the following year. It is the safest practice to sow from mid-May to mid-June, i.e. not too early. The quantity of larvae could be reduced by the treatment with Bacillus thuringiensis. The effective pest management should include selecting proper sowing date, non-irrigation and B. thuringiensis treatment. Sex pheromone trapping as a potential control measure requires further studies
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