Spallative ablation of dielectrics by X-ray laser

Short laser pulse in wide range of wavelengths, from infrared to X-ray, disturbs electron-ion equilibrium and rises pressure in a heated layer. The case where pulse duration $\tau_L$ is shorter than acoustic relaxation time $t_s$ is considered in the paper. It is shown that this short pulse may cause thermomechanical phenomena such as spallative ablation regardless to wavelength. While the physics of electron-ion relaxation on wavelength and various electron spectra of substances: there are spectra with an energy gap in semiconductors and dielectrics opposed to gapless continuous spectra in metals. The paper describes entire sequence of thermomechanical processes from expansion, nucleation, foaming, and nanostructuring to spallation with particular attention to spallation by X-ray pulse

Une extension du couplage de seniorite

The public: definitions and perceptions The public is a difficult concept to grasp. It exhibits contradictory meanings: a collective abstract entity that is based on a “togetherness” founded on the exercise of reason; a cumulative heterogeneous phenomenon formed into an audience by certain kinds of specialised proceedings; or, another possibility, the driving force of action aimed at modifying something of the individuals that one wishes to reach. In all these cases, it is not a self-defined social collective. However, we constantly speak of the public's point of view. Can we really contemplate a situation in which the public could be thought of as a potential enunciator of a point of view? Or at least as an interlocutor in communication with the institutions of which it is the public? This article describes the division between the status of the members of the public engaged in interpersonal communications with representatives of the institution and the status of the public as a collective abstract entity engaged in a “communication” with the institution

The broken-pair model versus the quasi-particle scheme: Two different formalisms?

The particle-number conserving Broken-Pair Model (BPM) and the Quasi-Particle Scheme (QPS) are shown to be nothing but two aspects of the same formalism. As a consequence, the old problem of the number-projection becomes elementary and BPM is algebraically as simple as QPS. Furthermore, owing to the existence of simple recursion formulas, BPM is also numerically as tractable as QPS. © 1982.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Remarkable properties of the broken-pair model. (III). Unified treatment of the broken-pair and quasiparticle formalisms

A unified treatment of the broken-pair and quasiparticle formalisms arises from both the existence of a non-unitary Bogoliubov-Valatin transformation and the identical structure of the broken-pair and quasiparticle spaces. © 1985.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Remarkable properties of the broken-pair model. (II). Relation with the quasiparticle scheme

A non-spurious quasiparticle scheme is presented, its number-projection being exactly the broken-pair model. From this property, quantities needed in the broken-pair approach are easily evaluated by making use of the extreme simplicity of the quasiparticle algebra. Applications to the hamiltonian operator and to one-body operators are presented for seniority υ = 0, 1 and 2. © 1983.SCOPUS: ar.jinfo:eu-repo/semantics/publishe