201,578 research outputs found
On continuity of Guo Wuwen function
We show that the functions g and gs introduced by Guo Wuwen in [4] are
continuous and semialgebraic. We use this fact to prove that the set Nn of
ordered n-tuples of real numbers, realizable by nonnegative matrices, is a
closed set
Electronic Properties of Graphene Nanoribbon on Si(001) Substrate
We show by first-principles calculations that the electronic properties of
zigzag graphene nanoribbons (Z-GNRs) adsorbed on Si(001) substrate strongly
depend on ribbon width and adsorption orientation. Only narrow Z-GNRs with even
rows of zigzag chains across their width adsorbed perpendicularly to the Si
dimer rows possess an energy gap, while wider Z-GNRs are metallic due to
width-dependent interface hybridization. The Z-GNRs can be metastably adsorbed
parallel to the Si dimer rows, but show uniform metallic nature independent of
ribbon width due to adsorption induced dangling-bond states on the Si surface.Comment: 13 pages, 3 figure
Plant uptake and the leaching of metals during the hot EDDS-enhanced phytoextraction process
Author name used in this publication: Chun-Ling LuoAuthor name used in this publication: Zhen-Guo ShenAuthor name used in this publication: Xiang-Dong Li2006-2007 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Comparison Between Simulated and Observational Results of Galaxy Formation for Large Scale Structures
The Millennium simulation is the largest numerical simulation of how minor fluctuations in the density of the universe’s dark matter distribution are amplified by gravity to develop into the large scale structures(LSS) and galaxy clusters seen today(Springel et al. 2005). Although the simulations have been compared with the astronomical observations of the local universe, the simulations have not been widely compared with high redshift, early universe observations. In our study we compare the simulation data(Wang et al. 2008; Guo et al. 2008(in preparation)) for the first time with observations from the COSMOS survey(Scoville et al. 2006). Three quantities are proposed to characterize the structures and the structures distribution, namely the percent area occupied by LSS at each redshift, the average area of LSS and the shapes as characterized by the square root of the area divided by the circumference. We calculate these quantities for both the observations and the simulations, and quantify discrepancies between the existing simulations and observations. In particular, the simulations exhibit earlier development of dense structures than is seen in the observational data
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