نتایج جستجو برای: silicate

تعداد نتایج: 10667  

Journal: :Journal of the Mineralogical Society of Japan 1983

2006
B. Sargent W. J. Forrest P. D ’ Alessio A. Li J. Najita D. M. Watson N. Calvet E. Furlan J. D. Green K. H. Kim G. C. Sloan C. H. Chen L. Hartmann J. R. Houck

The 8–14 µm emission spectra of 12 T Tauri stars in the Taurus/Auriga dark clouds and in the TW Hydrae association obtained with the Infrared Spectro-graph (IRS 1) on board Spitzer are analyzed. Assuming the 10 µm features originate from silicate grains in the optically thin surface layers of T Tauri disks, the 8–14 µm dust emissivity for each object is derived from its Spitzer spectrum. The em...

2007
P. Deroo H. Van Winckel T. Verhoelst M. Min M. Reyniers L. B. F. M. Waters

Context. In the generally accepted, but poorly documented model, silicate J-type C-stars are binary objects for which the silicate emission originates from a circumbinary or a circumcompanion disc. Aims. We aim at testing this hypothesis by a thorough spectral and spatial observational study of one object: IRAS 18006-3213. Methods. We obtained, analysed and modeled high spatial resolution inter...

2011
J. M. van Breemen M. Min J. E. Chiar L. B. F. M. Waters F. Kemper A. C. A. Boogert J. Cami A. G. G. M. Tielens

Context. Studying the composition of dust in the interstellar medium (ISM) is crucial for understanding the cycle of dust in our galaxy. Aims. The mid-infrared spectral signature of amorphous silicates, the most abundant dust species in the ISM, is studied in different lines-of-sight through the Galactic plane, thus probing different conditions in the ISM. Methods. We have analysed ten spectra ...

Journal: :Science 2010
Hyo-Joong Kim Steven A Benner

Lambert et al. (Reports, 19 February 2010, p. 984) reported that silicate ions catalyze the formation and stabilization of four- and six-carbon sugars from simple sugars, suggesting a possible prebiotic pathway for the synthesis of biologically important sugars. Here, we show that silicate has minimal impact in these respects, especially when compared to borate minerals.

Journal: :Chemical communications 2011
Chien-Cheng Li Yan-Wun Chen Ran-Jin Lin Ching-Chun Chang Kuei-Hsien Chen Hong-Ping Lin Li-Chyong Chen

A simple and convenient one-pot synthetic route to directly prepare a self-reductive mesoporous copper-iron-silicate (CuO(x)-Fe-silicate)-based catalyst has been developed. The resultant catalyst is highly active and stable in methanol reforming without needing a pre-reduction procedure.

Journal: :Dalton transactions 2016
Min Zhang Baoyu Wang Yanwei Zhang Weizhen Li Wenjun Gan Jingli Xu

This study reports the fabrication of magnetic copper silicate hierarchical hollow nanotubes, which are featured by a tailored complex wall structure and high surface area. Moreover, they exhibit excellent performance as an easily recycled adsorbent for protein separation. Particularly, this strategy can be extended as a general method to prepare other magnetic metal silicate hollow nanotubes.

Journal: :Journal of materials science. Materials in medicine 2015
J Massera A Kokkari T Närhi L Hupa

In this paper, we investigate the effect of substituting SrO for CaO in silicate and phosphate bioactive glasses on the human gingival fibroblast activity. In both materials the presence of SrO led to the formation of a CaP layer with partial Sr substitution for Ca. The layer at the surface of the silicate glass consisted of HAP whereas at the phosphate glasses it was close to the DCPD composit...

2014
Ian G. Richardson

C-(A)-S-H(I) is a calcium silicate hydrate that is studied extensively as a model for the main binding phase in concrete. It is a structurally imperfect form of 14 Å tobermorite that has variable composition and length of (alumino)silicate anions. New structural-chemical formulae are presented for single- and double-chain tobermorite-based phases and equations are provided that can be used to c...

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