Concept

Symétrie de rotation

Publications associées (239)

Experimental and theoretical study of intramolecular exchange in Ir2Rh2(CO)(12) and Ir-4(CO)(11)(mu-SO2)

Gabor Laurenczy, Raymond Roulet, Leonardo Guidoni, Zoltan Beni

As observed by variable-temperature and -pressure C-13 NMR, intramolecular carbonyl scrambling in Ir2Rh2(CO)(12) and Ir-4(CO)(11)(mu-SO2) proceeds via a 'change of basal face' mechanism. In both cases the site exchange process has a positive activation vol ...

2005

Symmetry breaking in mechanical systems

The first part of this thesis studies the problem of symmetry breaking in the context of simple mechanical systems with compact symmetry Lie group G. In this part we shall assume that the principal stratum of the G-action on the configuration space Q of a ...

EPFL2005

Optical injection of charge current in quantum wires: oscillations induced by excitonic effects

Benoît Marie Joseph Deveaud, Marc-André Dupertuis, Daniel Marti

We investigate the charge current that is optically injected by interference between one- and two-photon excitation in the presence of excitonic effects. We consider a realistic V-shaped quantum wire excited slightly below the band gap by two simultaneous ...

2005

Stokes eigenmodes in square domain and the stream function -- vorticity correlation

Emmanuel Leriche

"The Stokes eigenmodes in the square are numerically determined and their symmetry properties are identified. The spectra evolution laws are in excellent qualitative agreement with the theoretical asymptotic predictions proposed by Constantin and Foias (in ...

2004

The study of incommensurate structures as a probe to reveal atomic interactions in crystals

Gervais Chapuis, Alla Arakcheeva

The structure of aperiodic crystals which includes incommensurate, quasi- and composite crystals is usually described in spaces of higher dimension, the so called superspace. The main advantage of the superspace formalism is that an aperiodic structure in ...

2004

A comparison of experimental measurements and code results to determine flows in the JET SOL

Richard Pitts

Two reciprocating probe systems, at the same poloidal position at the top of the JET torus but toroidally separated by 180degrees, have been used to measure parallel flow in the scrape-off layer (SOL) of lower single-null, diverted plasmas. One system uses ...

2004

On facts and artefacts: The difficulty to evaluate an artificial nuclease

A no. of promising synthetic catalysts for the hydrolytic degrdn. of RNA have been developed in recent years. Some of them show remarkable selectivity for pyrimidine nucleotides. The general problem of all these studies is to distinguish between real effec ...

2003

Crystal structure and fluxional behaviour in solution of [Rh-4(CO)(6)(mu-Me2PCH2PMe2)(3)]

Gabor Laurenczy, Raymond Roulet, Kurt Schenk

[Rh-4 (CO)(6) (mu-Me2PCH2PMe2)(3)], the first example of a hexasubstituted derivative of Rh-4(CO)(12), has a ground state geometry in the solid state and in solution of C-s symmetry with four edge-bridging carbonyls and with each diphosphine ligand bridgin ...

2003

Dynamics of multi-photon processes in semiconductor heterostructures

The present work is devoted to the study of the dynamics of multi-photon processes in semiconductor heterostructures. A time-dependent description is important for understanding in detail the transient response of semiconductors excited by ultrashort optic ...

EPFL2003

Band features and strong correlations in 1D Peierls systems

Marco Grioni, Helmuth Berger, Luca Perfetti

High-resolution angle-resolved (ARPES) photoemission in the quasi-one dimensional (1D) Peierls systems (TaSe4)(2)I and K0.3MoO3 reveals spectral features with clear 1D character. Their dispersion and polarization dependence is consistent with open Fermi su ...

2002

Graph Chatbot

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.

Connectez-vous pour utiliser Chat avec Graph Search