Improvement of the sensitivity for the measurement of copper concentrations in soil by microwave-assisted laser-induced breakdown spectroscopy

International audienceThis study shows a 23-fold improvement of the sensitivity in the determination of copper in soil samples when using Microwave-Assisted Laser-Induced Breakdown Spectroscopy (MA-LIBS) compared with our conventional LIBS. This comparison between MA-LIBS and LIBS was performed with identical ablation conditions and detection geometry. The signal enhancement obtained with MA-LIBS allowed for the detection of spectral lines related to concentration values as low as 30 mg kg− 1 for copper and 23.3 mg kg− 1 for silver, which were not detected by LIBS

Introduction

Saint Martin est crédité de la première fondation monastique en Occident, à Ligugé. On sait qu’il fonda aussi Marmoutier pour poursuivre la vie monastique tout en étant évêque de Tours. Mais que signifiait ce « monachisme » martinien ? Le monasterium n’est-il pas simplement un ermitage, le lieu de vie d’un solitaire ? Or Sulpice Sévère rapporte aussi la présence de compagnons, sur un modèle déjà connu dans l’Orient méditerranéen. D’ailleurs, dans les dernières décennies du ive siècle, Eusèbe,..

Hypoallergenic fragment of Par j 2 increases functional expression of Toll-like receptors in atopic children

Parietaria judaica (Par j) is one of the main causes of allergy in the Mediterranean countries. The activation of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) inhibits nasal inflammation of atopic children

Optical Data Storage in Photosensitive Glasses and Spin State Transition Compounds

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HOBIT - un Concept Innovant pour le Transformation des Pratiques Pédagogiques

International audienceHOBIT désigne un nouveau concept destiné à transformer les pratiques pédagogiques concernant l’enseignement de l’optique. Sur une table technique interactive, il permet de placer des composants optiques factices et d’agir sur leurs réglages et de visualiser en temps réel non seulement le phénomène optique résultant mais aussi de bénéficier d'un soutien pédagogique en faisant appel à la réalité augmentée. Nous mettrons l’accent sur la notion de rupture pédagogique qui peut être atteinte avec ce nouveau concept à travers quelques exemples choisis

Mountain building in Taiwan: A thermokinematic model

The Taiwan mountain belt is classically viewed as a case example of a critical wedge growing essentially by frontal accretion and therefore submitted to distributed shortening. However, a number of observations call for a significant contribution of underplating to the growth of the orogenic wedge. We propose here a new thermokinematic model of the Taiwan mountain belt reconciling existing kinematic, thermometric and thermochronological constraints. In this model, shortening across the orogen is absorbed by slip on the most frontal faults of the foothills. Crustal thickening and exhumation are sustained by underplating beneath the easternmost portion of the wedge (Tananao Complex, TC), where the uplift rate is estimated to ~6.3 mm a^(−1), and beneath the westernmost internal region of the orogen (Hsueshan Range units, HR), where the uplift rate is estimated to ~4.2 mm a^(−1). Our model suggests that the TC units experienced a synchronous evolution along strike despite the southward propagation of the collision. It also indicates that they have reached a steady state in terms of cooling ages but not in terms of peak metamorphic temperatures. Exhumation of the HR units increases northward but has not yet reached an exhumational steady state. Presently, frontal accretion accounts for less than ~10% of the incoming flux of material into the orogen, although there is indication that it was contributing substantially more (~80%) before 4 Ma. The incoming flux of material accreted beneath the TC significantly increased 1.5 Ma ago. Our results also suggest that the flux of material accreted to the orogen corresponds to the top ~7 km of the upper crust of the underthrust Chinese margin. This indicates that a significant amount (~76%) of the underthrust material has been subducted into the mantle, probably because of the increase in density associated with metamorphism. We also show that the density distribution resulting from metamorphism within the orogenic wedge explains well the topography and the gravity field. By combining available geological data on the thermal and kinematic evolution of the wedge, our study sheds new light onto mountain building processes in Taiwan and allows for reappraising the initial structural architecture of the passive margin