12,054 research outputs found
Relativistic effects on the observed AGN luminosity distribution
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
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
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-[(CycloÂhexylÂidene)amino]-1-(4-methylÂphenÂyl)thioÂurea
In the title compound, C14H19N3S, the cycloÂhexane ring has a chair conformation. The almost planar aminoÂthioÂurea unit (r.m.s. deviation = 0.0062 Å) is aligned at a dihedral angle of 45.23 (8)° with respect to the benzene ring. InterÂmolecular 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
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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