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Journées de la Diffusion Neutronique : 4-10 juin 2010Les dépêches ...
Participants to the international HERCULES school will be welcome in LLB to perform their neutrons practicals : monday march 15th and wednesday 17st to friday 19th. |
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| Alain MENELLE, dépêche du 12-03-2010 | ||
Daniel Cribier est décédé vendredi dernier, 26 février à l'âge de 83 ans. En 1975, il est le premier directeur du tout nouveau Laboratoire Léon Brillouin. Il a ensuite dirigé l'Institut de recherche fondamentale du CEA, de 1987 à 1990. (Lien vers un communiqué CEA disponible uniquement en Intra ci dessous) |
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| Alain MENELLE, dépêche du 03-03-2010 | ||
Due to the widespread importance of water and the difficulty to study it in the so-called no man's land between 150 and 235 K, deeply supercooled bulk water is currently heavily debated. It speculates about its properties from extrapolations of experimental data on bulk water above 235 K and below 150 K, computer simulations, and experiments on confined water for which the finite size effects may prevent crystallization in the no man's land. However, it is far from obvious how experimental data on bulk water should be extrapolated to the temperature range of the no man's land or how relevant results from computer simulations and studies of confined water are for bulk water. In this paper the structural and dynamical properties of supercooled bulk water are tried to be understood from experimental results on confined water and comparisons with bulk water. We propose that a similar crossover from a high temperature |
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| Alain MENELLE, dépêche du 02-03-2010 | ||
-relaxation to a low temperature 
-relaxation occurs also for bulk water but at a higher temperature than for confined water due to the larger average number of hydrogen bonds between the water molecules in bulk water. In the case of bulk water the crossover is expected to occur around the critical temperature Ts![[approximate]](http://scitation.aip.org/stockgif3/ap.gif)
228 K when the buildup of an icelike tetrahedral network structure is completed. The proposed interpretation is the simplest one that is able to explain many of the peculiar properties of supercooled water. ©2010 American Institute of Physics