239 research outputs found
Ordered GeSi nanorings grown on patterned Si (001) substrates
An easy approach to fabricate ordered pattern using nanosphere lithography and reactive iron etching technology was demonstrated. Long-range ordered GeSi nanorings with 430 nm period were grown on patterned Si (001) substrates by molecular beam epitaxy. The size and shape of rings were closely associated with the size of capped GeSi quantum dots and the Si capping processes. Statistical analysis on the lateral size distribution shows that the high growth temperature and the long-term annealing can improve the uniformity of nanorings
(2,2′-Bipyridine-κ2 N,N′)bisÂ(4-methylÂbenzoato-κ2 O,O′)lead(II)
In the title compound, [Pb(C8H7O2)2(C10H8N2)], the PbII ion is coordinated by two N atoms from one 2,2′-bipyridine ligand and four O atoms from two 4-methylÂbenzoate anions in a distorted pseudo-square-pyramidal environment, considering one of the carboxylÂate anions as an apical ligand. Pairs of complex molÂecules related by inversion centers are organized into dimers via pairs of Pb⋯O interÂactions [3.185 (2) Å] and stacking interactions between 2,2′-bipyridine and 4-methylÂbenzoate ligands, with a mean distance between their planes of 3.491 Å
A promising routine to fabricate GeSi nanowires via self-assembly on miscut Si (001) substrates
Photometric Metallicity Calibration with SDSS and SCUSS and its Application to distant stars in the South Galactic Cap
Based on SDSS g, r and SCUSS (South Galactic Cap of u-band Sky Survey)
photometry, we develop a photometric calibration for estimating the stellar
metallicity from and colors by using the SDSS spectra of 32,542 F-
and G-type main sequence stars, which cover almost deg in the
south Galactic cap. The rms scatter of the photometric metallicity residuals
relative to spectrum-based metallicity is dex when , and
dex when . Due to the deeper and more accurate magnitude of SCUSS
band, the estimate can be used up to the faint magnitude of . This
application range of photometric metallicity calibration is wide enough so that
it can be used to study metallicity distribution of distant stars. In this
study, we select the Sagittarius (Sgr) stream and its neighboring field halo
stars in south Galactic cap to study their metallicity distribution. We find
that the Sgr stream at the cylindrical Galactocentric coordinate of
kpc, kpc exhibits a relative rich metallicity
distribution, and the neighboring field halo stars in our studied fields can be
modeled by two-Gaussian model, with peaks respectively at [Fe/H] and
[Fe/H].Comment: 8 pages, 7 figures, Accepted for publication in MNRA
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