Search results for "Fas"
showing 10 items of 2015 documents
Parabolic pulse formation and applications
2009
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such pulses as well as the results obtained in a wide-range of experimental configurations.
Optical bullets and "rockets" in nonlinear dissipative systems and their transformations and interactions
2006
We demonstrate the existence of stable optical light bullets in nonlinear dissipative media for both cases of normal and anomalous chromatic dispersion. The prediction is based on direct numerical simulations of the (3+1)-dimensional complex cubic-quintic GinzburgLandau equation. We do not impose conditions of spherical or cylindrical symmetry. Regions of existence of stable bullets are determined in the parameter space. Beyond the domain of parameters where stable bullets are found, unstable bullets can be transformed into >rockets> i.e. bullets elongated in the temporal domain. A few examples of the interaction between two optical bullets are considered using spatial and temporal interact…
Complex rogue wave in the fiber optics
2016
This manuscript presents the generation of complex rogue waves related to nonlinear instabilities occurring through the propagation of light in standard optical fibers. Linear and nonlinear physical phenomena involved are first listed, in particular some of them by analogy with the field of hydrodynamics. The different forms of rogue waves induced by the modulation instability process are then presented. They are also known as "breathers", and they are obtained by solving the nonlinear Schrödinger equation. From these exact solutions, various experimental systems were designed by means of numerical simulations based on two rogue-wave excitation methods. The first one is an exact generation …
Universal soliton pattern formations in passively mode-locked fiber lasers
2011
International audience; We investigate multiple-soliton pattern formations in a figure-of-eight passively mode-locked fiber laser. Operation in the anomalous dispersion regime with a double-clad fiber amplifier allows generation of up to several hundreds of solitons per round trip. We report the observation of remarkable soliton distributions: soliton gas, soliton liquid, soliton polycrystal, and soliton crystal, thus indicating the universality of such complexes.
Charge-transfer driven by ultrafast spin-transition in a CoFe Prussian blue analogue
2020
Photoinduced charge-transfer is an important process in nature and technology and is responsible for the emergence of exotic functionalities, such as magnetic order for cyanide-bridged bimetallic coordination networks. Despite its broad interest and intensive developments in chemistry and material sciences, the atomic-scale description of the initial photoinduced process, which couples intermetallic charge-transfer and spin transition, has been debated for decades; it has been beyond reach due to its extreme speed. Here we study this process in a prototype cyanide-bridged CoFe system by femtosecond X-ray and optical absorption spectroscopies, enabling the disentanglement of ultrafast electr…
New molecular aspects of regulation of mitochondrial activity by fenofibrate and fasting
2000
Abstract Fenofibrate and fasting are known to regulate several genes involved in lipid metabolism in a similar way. In this study measuring several mitochondrial enzyme activities, we demonstrate that, in contrast to citrate synthase and complex II, cytochrome c oxidase (COX) is a specific target of these two treatments. In mouse liver organelles, Western blot experiments indicated that mitochondrial levels of p43, a mitochondrial T3 receptor, and mitochondrial peroxisome proliferator activated receptor (mt-PPAR), previously described as a dimeric partner of p43 in the organelle, are increased by both fenofibrate and fasting. In addition, in PPARα-deficient mice, this influence was abolishe…
Culture nationale et antifascisme au sein de la gauche française (1934-1939)
1998
En nouant en gerbe les conclusions de travaux récents, il s'agit ici de s'interroger sur les liens entre l'antifascisme et les pratiques et politiques culturelles portées par les courants politiques et associatifs de la gauche française . Trois entrées sont privilégiées : la formalisation du thème de " la défense de la culture ", les formes prises par ce travail de définition de la culture et, plus succinctement, l'inscription de cette thématique au sein des stratégies partisanes.
L'antifascisme et son analyse
2000
Antifascisme et nation. Les gauches européennes au temps du Front populaire
1998
"Giuseppe Antonio Borgese et le sens de la littérature italienne"
2009
Si Borgese n’adhéra pas officiellement au fascisme, ses rapports avec le régime ne furent pas exempts de quelques compromissions avant la rupture de 1934 et le choix de l’exil politique. Borgese fut non seulement théoricien et critique mais également auteur et par conséquent objet à son tour d’une réception critique. Or il apparaît que la production borgesienne des années 1920 et du début des années 1930 n’est pas étrangère au climat culturel qui s’affirma sous le fascisme. Se Borgese non aderì ufficialmente al fascismo, i suoi rapporti col regime non furono esenti da qualche compromissione prima della rottura del 1934 e della scelta dell’esilio politico. Borgese non fu solo teorico e criti…