0000000000433567
AUTHOR
Hervé Guillon
showing 3 related works from this author
η⇌μ exchange bonding mode of bidentate tmeda ligand. Molecular structure of [Y(tmhd)3]2(μ-tmeda)
2003
Abstract The reaction between the yttrium β-diketonate complexes Y(tmhd)3(H2O)x (x=0 or 1) and 0.5 or 1 equivalent of N,N,N′,N′-tetramethylethylenediamine (tmeda=Me2NCH2CH2NMe2) in hexane at room temperature afforded [Y(tmhd)3]2(tmeda) (1) and Y(tmhd)3(tmeda) (2) derivatives, respectively. They have been characterized by FT-IR, 1H NMR spectroscopy and by single crystal X-ray diffraction for 1. Variable temperature 1H NMR experiments indicated an equilibrium between 1 and 2. Their thermal behaviors were characterized by TGA and sublimation experiments. 2 is converted into compound 1 by heating over 100 °C. These precursors were used for the growth of Y2O3 and YBa2Cu3O7 − x films by pulsed in…
Improved discrimination of subglacial and periglacial erosion using10Be concentration measurements in subglacial and supraglacial sediment load of th…
2015
Deciphering the complex interplays between climate, uplift and erosion is not straightforward and estimating present-day erosion rates can provide useful insights. Glaciers are thought to be powerful erosional agents, but most published ‘glacial’ erosion rates combine periglacial, subglacial and proglacial erosion processes. Within a glaciated catchment, sediments found in subglacial streams originate either from glacial erosion of substratum or from the rock walls above the glacier that contribute to the supraglacial load. Terrestrial cosmogenic nuclides (TCN) are produced by interactions between cosmic ray particles and element targets at the surface of the Earth, but their concentration …
Proglacial sediment dynamics from daily to seasonal scales in a glaciated Alpine catchment (Bossons glacier, Mont Blanc massif, France)
2018
The sediment yields of Alpine catchments are commonly determined from streamload measurements made some distance downstream from glaciers. However, this approach indiscriminately integrates erosion processes occurring in both the glacial and proglacial areas. A specific method is required to ascertain the respective inputs from (i) subglacial and supraglacial sediments, (ii) proglacial hillslopes and (iii) proglacial alluvial areas or sandurs. This issue is addressed here by combining high‐resolution monitoring (2 min) of suspended sediment concentrations at different locations within a catchment with discharge gauging and precipitation data. This methodological framework is applied to two …