Search results for "Rossi"

On the Intrinsic Population of the Lowest Triplet State of Thymine

2007

The population of the lowest triplet state of thymine after near-UV irradiation has been established, on the basis of CASPT2//CASSCF quantum chemical calculations, to take place via three distinct intersystem crossing mechanisms from the initially populated singlet bright 1pipi* state. Two singlet-triplet crossings have been found along the minimum-energy path for ultrafast decay of the singlet state at 4.8 and 4.0 eV, involving the lowest 3npi* and 3pipi* states, respectively. Large spin-orbit coupling elements predict efficient intersystem crossing processes in both cases. Another mechanism involving energy transfer from the lowest 1npi* state with much larger spin-orbit coupling terms ca…

Ideal and physical barrier problems for non-linear systems driven by normal and Poissonian white noise via path integral method

2016

Abstract In this paper, the probability density evolution of Markov processes is analyzed for a class of barrier problems specified in terms of certain boundary conditions. The standard case of computing the probability density of the response is associated with natural boundary conditions, and the first passage problem is associated with absorbing boundaries. In contrast, herein we consider the more general case of partially reflecting boundaries and the effect of these boundaries on the probability density of the response. In fact, both standard cases can be considered special cases of the general problem. We provide solutions by means of the path integral method for half- and single-degr…

The multi-state CASPT2 method

1998

Abstract An extension of the multiconfigurational second-order perturbation approach CASPT2 is suggested, where several electronic states are coupled at second order via an effective-Hamiltonian approach. The method has been implemented into the MOLCAS-4 program system, where it will replace the single-state CASPT2 program. The accuracy of the method is illustrated through calculations of the ionic-neutral avoided crossing in the potential curves for LiF and of the valence-Rydberg mixing in the V-state of the ethylene molecule.

Multipactor RF Breakdown in Coaxial Transmission Lines With Digitally Modulated Signals

2016

The aim of this paper is the study of the RF multipactor breakdown in coaxial transmission lines excited by a single carrier with a digitally modulated signal. Employing an in-house developed code, numerical simulations are performed to determine the RF multipactor voltage threshold for several digitally modulated signals under different modulations schemes: quadrature phase-shift keying, 16-quadrature amplitude modulation, 16-amplitude and phase-shift keying, and 32-amplitude and phase-shift keying. Moreover, a coarse method based on the envelope integration to determine the RF multipactor voltage threshold when involving arbitrary digital modulations is also presented. These results are a…

Experimental Analysis of the Multipactor Effect With RF Pulsed Signals

2015

The main goal of this letter is the analysis of the multipactor effect within a coaxial waveguide excited by an RF pulsed signal. The variation of the multipactor RF voltage thresholdwiththe ON interval length of the pulse has been analyzed. To reach this aim, an in-house multipactor simulation code based on the Monte-Carlo algorithm has been implemented. The numerical simulations show that the multipactor RF voltage threshold increases as the ON pulse interval diminishes. In addition, an experiment was carried out to validate the proposed theoretical model, and demonstrating the excellent agreement between the theory and the experimental data. Finally, the results are compared with the 20-…

L'ozio di Rossini: un problema politico transnazionale nella Parigi degli anni Trenta dell'Ottocent

2020

Fin dai tempi di Stendhal la descrizione di Rossini come un uomo ozioso è uno dei tropi più radicati nelle biografie del compositore. Testi recenti consigliano di considerarla una leggenda priva di fondamento; ma negarne la veridicità non equivale a cancellare la sua esistenza in quanto fatto storiografico. Questo articolo indaga il fenomeno in una prospettiva culturale, concentrandosi sulla dimensione politica e transnazionale che il discorso dell’ozio di Rossini assunse nella Parigi degli anni Trenta dell’Ottocento. Attraverso l’analisi della stampa parigina e degli scritti degli esuli italiani rifugiati in Francia, tale discorso si rivela un luogo privilegiato scelto da speakers politici…

Nell'«académie musicale de chant» di Parigi. Rossini al Théâtre-Italien nei "feuilletons" di Delécluze (1832-1863)

2018

The essay explores the reception of Rossini’s Italian operas in the writings of Étienne-Jean Delécluze. A leading figure in the Parisian cultural milieu of his time, Delécluze reviewed performances at the Théâtre Italien for the influential «Journal des débats» between 1832 and 1863. He developed an interpretative frame based on the idea that the Théâtre-Italien should function as as a “school of singing” for Paris, and identified Rossini’s operas as canonical texts that such a school should preserve and promote, in opposition to more recent trends originating from Italy. The breakdown of this cultural project, which had met with some significant public support, is probably linked to the st…

Mössbauer effect study of the temperature and pressure dependence of the singlet-quintet intersystem crossing dynamics in an iron(II) spin crossover …

1988

The lineshapes of Mossbauer spectra of the iron(II) spin crossover complex [Fe(6-mepy)3 tren] (PF6)2 are affected by the dynamics of the HS⇌LS equilibrium. The lineshapes are reproduced with a stochastic two-state-relaxation-model yielding rate constants similar to those determined for related complexes in solution. Application of an external pressure of 150 MPa increases the relaxation rate.

NUOVI COPOLMERI BIOCOMPATIBILI A BASE DI POLI-IDROSSIETILASPARTAMMIDE PER IL NONVIRAL GENE DELIVERY

2012

Nouvelles données pétrographiques sur les sarcophages du musée Carnavalet à Paris

2009

International audience