Laser-induced electron detachment or ionization of atoms and negative ions is considered. In the context of the saddle-point evaluation of the strong-field approximation (SFA), the velocity maps of the direct electrons (those that do not undergo rescattering) exhibit a characteristic structure due to the constructive and destructive interference of electrons liberated from their parent atoms/ions within certain windows of time. This structure is defined by the above-threshold ionization rings at fixed electron energy and by two sets of curves in momentum space on which destructive interference occurs. The spectra obtained with the SFA are compared with those obtained by numerical solution of the time-dependent Schrödinger equation. For detachment, the agreement is excellent. For ionization, the effect of the Coulomb field is most pronounced for electrons emitted in a direction close to laser polarization, while for near-perpendicular emission the qualitative appearance of the spectrum is unaffected.

A partir de alguns conceitos básicos de teorias de gênero, este artigo visa descrever o gênero e-mail pessoal em inglês, como parte de um projeto em andamento que tem implicações pedagógicas. Os dados foram coletados em 30 e-mails escritos por keypals de diferentes países. Nossa análise focaliza os aspectos sociais e culturais do gênero (principalmente o conceito de propósito comunicativo), mas também considera a linguagem e as convenções formais utilizadas. Na conclusão, apontamos que uma das principais características desse gênero é justamente seu caráter híbrido.

This paper presents the research based on experiment performing of the deep-drawing process with wall-thickness thinning. The corresponding measurement equipment was applied, where with the process analysis and with the applied stochastic modelling method, the physical mathematical model for the deep-drawing force is obtained, in the form: F i =  f ( ψ , s 1 , μ ). The applied modelling and simulation methods in this paper, can also be used for defining the optimal values of bigger number of the technological process parameters of deep drawing, with wall-thickness thinning, by the applied higher order mathematical model. Principally, it would relate to the reduction of the drawing force with the obtained products, according to the demanded quality along with the minimum energy consumption. DOI: http://dx.doi.org/10.5755/j01.mech.18.2.1563