Introduction: The compositional characteristics of the Earth's core-mantle system are best described by a model that recognizes that the present upper mantle is not in equilibrium with the core and that metal-silicate differentiation was in response to secular changes in equilibrium conditions [1-5 and references therein]. Au) that are ~100-fold depleted relative to chondritic meteorites [6-7]....

Arsenic (As) contaminated aquifers contain iron minerals and clays that strongly bind As at their surfaces. It was suggested that As mobilization is driven by natural organic matter (including fulvic acids (FA) and humic acids (HA)) present in the aquifers either via providing reducing equivalents for reductive dissolution of Fe(III) (hydr)oxides or via competitive desorption of As from the min...

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...

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...

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 ...

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.

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.

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.