La formation de O+ et N+ par impact d'électrons de faible énergie sur l'hémioxyde d'azote.

peer reviewedThe O+ and N+ dissociation channels in N2O have been investigated by electroionization using ion kinetic energy and mass analysis. Appearance enegies are measured as a function of the translational energy of the fragment ions. The different dissociation mechanisms are discussed

Excitation and Deexcitation of Benzene

This chapter contains sections titled: - Introduction; - The Nature of the Lower Excited States of Benzene; - Transitions Between Lower Energy States; - Excited State Geometry; - The Influence of the Environment on Electronic States; - The S1 ↔ S0 Radiative Transition; - The S1 ↔ Triplet Radiationless Transition; - The S1 → S0 Radiationless Transition; - The T1 → S0 Phosphorescence Transition; - The T1 → S0 Radiationless Transition; - Transitions from Higher (n > 1) Excited States; - Relevant Photochemical Reactions of Excited States of Benzene; - Benzene Excimer; - Conclusioninfo:eu-repo/semantics/publishedVersio

Comparing Notes: Recording and Criticism

This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice

Wider Still and Wider: British Music Criticism since the Second World War

This chapter provides the first historical examination of music criticism in Britain since the Second World War. In the process, it also challenges the simplistic prevailing view of this being a period of decline from a golden age in music criticism

Electronic, rotational and vibrational predissociations in the decay of electronically excited molecular ions

A review is made of experimental and theoretical studies about the occurrence of electronic predissociation processes either allowed or forbidden, in the dissociation of CH+, [Math], CO+, [Math], NO+ [Math] and N2O+. The importance of rotational predissociation is emphasized in the dissociation of diatomic ionized hydrides and its occurrence in the decay of [Math] brings attention to the possibility that such a process could play an important role in the apparance of metastable ions in the mass spectra of complex molecules, especially when the loss of H or H2 is involved. The discussion, with the help of correlation diagrams, of some dissociation channels of C2H3F+ and CH3OH+, shows the coexistence in these mechanisms of adiabatic processes, principally due to the occurrence of "avoided crossings” or of "conical intersections" and of non-adiabatic processes such as electronically forbidden predissociations. The role of autoionization in the population of dissociation processes has been emphasized each time it was involved

L'ionisation dissociative du fluorure de méthyle. La formation de CH2+ et CH3+.

peer reviewedThe decay of ionized CH3F was investigated in the CH2+ and CH3+ dissiciation channels by electronionization and fixed wavelength photoionization using HeI and NeI resonance lines. The translational energy spectra, ionization efficiency curves and kinetic energy-versus-appearance enegy diagrams of both ions were measured. Although dissociative autoionization is the prominent dissociation mechanism for the appearance of CH2+ and CH3+, direct dissociative ionization is observed for CH2+ at 23.4 eV and for CH3+ at 16.5 eV