Search results for "version"
showing 10 items of 1591 documents
Nanopore charge inversion and current-voltage curves in mixtures of asymmetric electrolytes
2018
[EN] We consider the screening of the negative charges (carboxylic acid groups) fixed on the surface of a conical-shaped track-etched nanopore by divalent magnesium (Mg2+) and trivalent lanthanum (La3+). The experimental current (I)-voltage (V) curves and current rectification ratios allow discussing fundamental questions about the overcompensation of spatially-fixed charges by multivalent ions over nanoscale volumes. The effects of charge inversion or reversal on nanopore transport are discussed in mixtures of asymmetric electrolytes (LaCl3 and MgCl2 with KCl). In particular, pore charge inversion is demonstrated for La3+ as well as for mixtures of this trivalent ion at low concentrations …
Fe-doped Beta zeolite from organotemplate-free synthesis for NH3-SCR of NOx
2016
Two types of Beta zeolites, one from organotemplate-free synthesis with a Si/Al ratio of 9 and the other from a commercial one with a Si/Al ratio of 19, were employed here to dope Fe for NH3-SCR of NOx. Fe-Beta (Si/Al = 9) exhibits much higher activity than Fe-Beta (Si/Al = 19), especially at low-temperature regions (<250 °C). In addition, it also exhibits better hydrothermal stability as compared with Fe-Beta (Si/Al = 19), which demonstrates that it is a promising SCR catalyst with good activity as well as hydrothermal stability. The correlation between the quantitative calculation of the content of isolated Fe3+ in Beta zeolites and the NO conversion rate at 150 °C shows a linear relation…
Understanding the Stability and Recrystallization Behavior of Amorphous Zinc Phosphate
2021
Zinc phosphate, an important pigment in phosphate conversion coatings, forms protective films on rubbing surfaces. We have simulated the underlying reactions under shear by ball-milling zinc phosphate and monitored the reaction of hopeite (Zn3(PO4)2·4H2O) and the retarded recrystallization of the amorphous reaction product by powder X-ray diffraction (PXRD) and quantitative infrared (IR) spectroscopy. Abrasion of stainless steel was simulated by addition of pure 57Fe. The results provide insight into the chemistry of phosphate conversion coatings or during battery cycling of metal phosphates and give theoretical guidance for the preparation of amorphous phosphates. Thermal analysis revealed…
Inversions de température dans le Jura
2018
L'étude des inversions, événements climatiques qui provoquent de nombreux pics de pollution nocifs, est primordiale. Quatorze sites composés de deux stations proches et quatre autres mettant en relation une station de plaine avec une station de montagne permettent d'analyser la fréquence, l'intensité et la durée des inversions locales et régionales. La fréquence moyenne des inversions est élevée lors des tn (50 %) avec des maximums supérieurs à 70% en certains sites et en décembre. L'intensité des inversions tant locales que régionales est faible (respectivement 2°C et 1°C en moyenne). La durée des inversions est faible : 60 % d'entre elles concernent juste la fin de nuit. Parmi les inversi…
Om ordföljden i början av huvudsatser och bisatser i skriven och talad inlärarsvenska
1999
”Så nu jag frågar” : inlärning av inversion vid topikalisering
2014
Tutkielman tarkoituksena on selvittää, kuinka paljon ruotsia opiskelevien yläkoululaisten ja lukiolaisten taito käyttää käännettyä sanajärjestystä päälauseissa kehittyy kolmen kouluvuoden aikana. Lisäksi selvitetään, ennustaako prosessoitavuusteoria oppijoiden kehityksen. Lisäksi tutkielmassa on tarkoitus tarkastella, mitkä asiat käännetyn sanajärjestyksen käytön onnistumiseen vaikuttavat. Aineisto koostuu kuuden kielenoppijan kirjoitelmista kolmen vuoden ajalta. Kielenoppijoista kolme on yläkoululaisia ja kolme lukiolaisia. Kirjoitelmat on kerätty Jyväskylän yliopiston kielten laitoksen ja Soveltavan kielentutkimuksen keskuksen yhteistä tutkimushanketta, Toisen kielen oppimisen polut -hank…
Ionic liquid binary mixtures: Promising reaction media for carbohydrate conversion into 5-hydroxymethylfurfural
2014
Abstract The conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF) has been studied in binary mixtures of ionic liquids (ILs), using strongly acidic resin Amberlyst 15 as the catalyst. In particular, both mono- and disaccharides, such as fructose, glucose and sucrose have been investigated. Considering the favorable effect exerted by chloride-based ionic liquids in the dissolution of carbohydrates, we used binary mixtures of 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) with [bmim + ] based ionic liquids differing in size, shape and coordination ability of the anion ([bmim][BF 4 ], [bmim][N(CF 3 SO 2 ) 2 ], [bmim][N(CN) 2 ], [bmim][SbF 6 ] and [bmim][CF 3 SO 3 ]). Carbohydrat…
Ligand-Centred Fluorescence and Electronic Relaxation Cascade at Vibrational Time Scales in Transition-Metal Complexes
2015
Using femtosecond-resolved photoluminescence up-conversion, we report the observation of the fluorescence of the high-lying ligand-centered (LC) electronic state upon 266 nm excitation of an iridium complex, Ir(ppy)(3), with a lifetime of 70 +/- 10 fs. It is accompanied by a simultaneous emission of all lower-lying electronic states, except the lowest triplet metal-to-ligand charge-transfer ((MLCT)-M-3) state that shows a rise on the same time scale. Thus, we observe the departure, the intermediate steps, and the arrival of the relaxation cascade spanning similar to 1.6 eV from the (LC)-L-1 state to the lowest 3MLCT state, which then yields the long-lived luminescence of the molecule. This …
Dealing with risk: Gender, stakes, and probability effects
2015
This paper investigates how subjects deal with financial risk, both "upside" (with a small chance of a high payoff) and "downside" (with a small chance of a low payoff). We find that the same people who avoid risk in the downside setting tend to make more risky choices in the upside one. The experiment is designed to disentangle the probability-weighting and utility-curvature components of risk attitudes, and to differentiate settings in which gender differences arise from those in which they do not. Women are more risk averse for downside risks, but gender differences are diminished for upside risks.
Perception du risque dépendance et demande d'assurance : une analyse à partir de l'enquête PATER
2013
Dans la littérature économique, de nombreux travaux tentent d'expliquer pourquoi les individus s’assurent aussi peu contre la dépendance. Du côté de l’offre, différents freins possibles au développement du marché de l’assurance dépendance ont d’ores et déjà été pointés du doigt par la littérature. Les estimations récentes montrent néanmoins que les limites imputables à l’offre ne suffisent pas à expliquer le faible développement du marché : même si les assurances étaient moins coûteuses et les couvertures proposées plus larges, la majorité des individus ne souscrirait toujours pas d’assurance. Il est donc nécessaire d’aller trouver des explications du côté de la demande d’assurance dépendan…