The decomposition of ammonium heptamolybdate was investigated by in situ XAFS and in situ XRD to elucidate the influence of different atmospheres on the products formed the formation of different decomposition products and various intermediates is described in detail.

Jets or localized strong currents in planetary atmospheres, as well as in the Earth's oceans, are often associated with sharp potential-vorticity gradients owing to the inherent balance exhibited by these flows. Here, we explore and quantify jet sharpening in a simple idealized single-layer quasi-geostrophic model on a mid-latitude β-plane. The advantages of this idealization are that just two ...

We revealed the inherent instability of α''-Fe16N2 in hydrogenous atmospheres due to the denitrification toward α-Fe by forming NH3 at the particle surface. Coating the particle surface with SiO2 to suppress the formation of NH3 has proven to be a simple yet powerful method to enhance the stability of α''-Fe16N2 in hydrogenous atmospheres.

The scientific aims that motivate our work on this project are: (1) to understand quantitatively the multiple-scattering physics underlying spaceborne hyperspectral and lidar observations of atmospheric aerosols and surface reflectivity; (2) to develop rigorous, stable (i.e., genuinely useful) inverse methods to interpret such observations in terms of geophysical quantities, based on the mathem...

The residual range delay error due to an incompletely modelled tropospheric propagation delay can usually be ignored by the average user of wide-area differential GPS. In general the atmosphere is “well behaved” and the use of standard range delay algorithms supplied with standard atmosphere parameter values will adequately model the “average” atmospheric conditions. It is possible however, for...

The functioning of Arctic ecosystems is not only critically affected by climate change, but it also has the potential for major positive feedback on climate. There is, however, relatively little information on the role, patterns, and vulnerabilities of CO2 fluxes during the nonsummer seasons in Arctic ecosystems. Presented here is a year-round study of CO2 fluxes in an Alaskan Arctic tussock tu...

General information. All manipulations were performed using Schlenk techniques under an Ar atmosphere. All solvents were dried and purified by standard procedures. Spectroscopic grade dichloromethane was used for all optical measurements. NMR spectra were recorded on Bruker DPX-200, AV 300 or AV 500 MHz spectrometers. H and C chemical shifts are given versus SiMe4 and were determined by referen...

We use radiative transfer calculations to reproduce the basic appearance of Mg II lines observed from Mira variables. These lines have centroids that are blueshifted by at least 30 km s −1 from the stellar rest frame. It is unlikely that flow velocities in the stellar atmospheres are this fast, so radiative transfer effects must be responsible for this behavior. Published hydrodynamic models pr...