Search results for "Density"
showing 10 items of 4402 documents
Morphological and chemical dynamics upon electrochemical cyclic sodiation of electrochromic tungsten oxide coatings extracted by in situ ellipsometry.
2020
The sodiation–desodiation process of sputtered amorphous electrochromic tungsten oxide coatings in an aqueous-based medium was simultaneously monitored over 99 cycles by cyclic voltammetry and in situ spectroscopic ellipsometry. This allowed extracting the evolution of optical and geometrical parameters upon cycling. The resulting electrochemical coloring-bleaching process was dynamically fitted in the 1.8–2.8 eV optical range with a four-phase model including a constrained spline parametrization of the dielectric function. This allows real time access to thickness, surface roughness, and dielectric function of N a x W O 3 . The temporal evolution of the latter in the fully colored state wa…
Symmetry breakings in a metal organic framework with a confined guest
2020
The MOF $[{\text{Fe(tvp)}}_{2}{(\text{NCS})}_{2}]\ifmmode\cdot\else\textperiodcentered\fi{}2\text{BzCHO}$ is demonstrated to undergo a complex sequence of phase transitions and spin-crossover behavior of its constitutive ${\text{Fe}}^{\text{II}}$ ions upon adsorption of benzaldehyde guest molecules. Our study, combining Raman and synchrotron x-ray diffraction measurements on a single crystal, reveals that the conversion from the pure high-spin to the pure low-spin phases implies a rich sequence of intermediate phases, with symmetry breaking forming at least three different space groups. These different symmetries involve spin-state ordering, ligand ordering, and guest ordering, interpreted …
Spectral density estimate for alpha-stable p-adic processes
2012
International audience
Système de prise d'images haute résolution pour l'analyse de projection de particules : application à l'épandage centrifuge d'engrais
2002
This paper describes the design of a high resolution low cost imaging system for the analysis of high speed particle projection. This system, based on a camera and a set of flashes, is used to characterize the centrifugal spreading of fertilizer particles ejected at speeds of environ 30 m s. Multiexposure images collected with the camera installed perpendicular to the output flow of granules are analysed to estimate the trajectories of the fertilizer granules. Very good results are obtained with the Markov random fields method, in comparison with others.
Copper Dynamics and Impact on Microbial Communities in Soils of Variable Organic Status
2008
International audience; The effect of soil organic status on copper impact was investigated by means of a microcosm study carried out on a vineyard soil that had been amended with varying types of organic matter during a previous long-term field experiment. Soil microcosms were contaminated at 250 mg Cu kg−1 and incubated for 35 days. Copper distribution and dynamics were assessed in the solid matrix by a sequential extraction procedure and in the soil solution by measuring total and free exchangeable copper concentrations. Copper bioavailability was also measured with a whole-cell biosensor. Modifications of microbial communities were assessed by means of biomass-C measurements and charact…
Favoriser l'acceptation de légumes chez l'enfant. Comparaison des stratégies d'exposition répétée, d'association flaveur-flaveur et d'association fla…
2012
La consommation de légumes étant inférieure aux recommandations nutritionnelles, et particulièrement chez les enfants, mieux comprendre les facteurs qui favorisent leur acceptation est essentiel. Différentes stratégies visant à favoriser l’acceptation d’aliments sont décrites. Il s’agit de l’exposition répétée (RE), de l’association flaveur-flaveur (AFF) et de l’association flaveur-nutriment (AFN). La présente étude a pour objectifs de comparer l’efficacité de ces trois stratégies, de mesurer la stabilité de leurs effets, et d’expliquer par l’histoire alimentaire de chacun les différences individuelles d’acceptation de légumes. Une purée d’artichaut (légume cible, généralement peu apprécié)…
A Push-Pull Mechanism Helps Design Highly Competent G-Quadruplex-DNA Catalysts
2021
International audience; Massive efforts are currently being invested to improve the performance, versatility, and scope of applications of nucleic acid catalysts. G-quadruplex (G4)/hemin DNAzymes are of particular interest owing to their structural programmability and chemical robustness. However, optimized catalytic efficiency is still bottleneck and the activation mechanism is unclear. Herein, we have designed a series of parallel G4s with different proximal cytosine (dC) derivatives to fine-tune the hemin-binding pocket for G4-DNAzymes. Combining theoretical and experimental methods, we have assessed the dependence of catalytic enhancement on the electronic properties of proximal dCs and…
Dietary variety in infants by the end of the 1st year: insights from a new questionnaire
2019
There are data on the nutritional composition of foods dedicated to infants but descriptions of the infant's diet in terms of energy density (ED) are sparse. Besides, around the age of 1 year, the infant's diet shifts from foods specifically dedicated to infants to a diet composed of adult foods making this time period of interest. Our objective was to describe the ED of the consumed vegetable, the infants' exposure to dietary ED variability for vegetable-based recipes and whether this was linked to individual characteristics like sex, z-BMI or duration of breastfeeding and the age at the onset of complementary feeding. When their infant was 11 months old, parents completed a 3-month retros…
Morphology and yield response to weed pressure by corn hybrids differing in canopy architecture
2001
Abstract Recently, corn ( Zea mays L.) hybrids accumulating more leaf area above the ear, maturing earlier, yielding better in narrower row spacings and tolerating higher population densities than conventional hybrids have been developed. However, no research has been conducted to assess their ability to compete with weeds. The objective of this study was to quantify morphological and grain yield responses of hybrids with differing canopy architectures to the presence and absence of weeds. Field experiments were conducted in 1996, 1997, and 1998 at Ste. Anne de Bellevue, Quebec and in 1996 at Ottawa, Ontario. Three hybrids, leafy reduced-stature (LRS), late maturing big leaf (LMBL), and con…
Soil fungal communities ecology: a biogeographical approach
2011
Affiche, résumé; International audience