Time-dependent theoretical description of molecular autoionization produced by femtosecond xuv laser pulses

ABSTRACT: We present a nonperturbative time-dependent theoretical method to study H2 ionization with femtosecond laser pulses when the photon energy is large enough to populate the Q1 (25–28 eV) and Q2 (30–37 eV) doubly excited autoionizing states. We have investigated the role of these states in dissociative ionization of H2 and analyzed, in the time domain, the onset of the resonant peaks appearing in the proton kinetic energy distribution. Their dependence on photon frequency and pulse duration is also analyzed. The results are compared with available experimental data and with previous theoretical results obtained within a stationary perturbative approach. The method allows us as well to obtain dissociation yields corresponding to the decay of doubly excited states into two H atoms. The calculated H(n=2) yields are in good agreement with the experimental ones

erfiles decisionales de jugadores y jugadoras de voleibol de diferente nivel de pericia. (Decisional profiles of volleyball players of different expertise level.)

<p><strong>Resumen</strong></p><p align="justify">La toma de decisiones por parte de los deportistas se viene estudiando como un tipo de habilidad cognitiva. En este estudio se parte de una perspectiva motivacional y emocional de la toma de decisiones en el deporte, que ha recibido una menor atenci&oacute;n en la literatura. Se aplica el Cuestionario de Estilos de Toma de Decisi&oacute;n en el Deporte-CETD (Ruiz y Graupera, 2005) que eval&uacute;a tres escalas: Competencia Decisional Percibida, Ansiedad y Agobio al Decidir y Compromiso en el Aprendizaje Decisional. Se toma una muestra de 121 jugadoras (76) y jugadores (45) de voleibol de diferente nivel de pericia deportiva: auton&oacute;mico, nacional e internacional. Los resultados muestran que las escalas del cuestionario tienen una buena fiabilidad cuando se aplican a muestras mono-deportivas. Las jugadoras y jugadores de voleibol tienen un perfil decisional muy similar (no se encuentran diferencias significativas), con una moderada percepci&oacute;n de competencia, baja ansiedad y alto compromiso (perfil en V). Seg&uacute;n aumenta el nivel deportivo se incrementa moderadamente el compromiso y la percepci&oacute;n de competencia, mientras que decrece considerablemente la ansiedad ante la toma de decisiones. Como consecuencia el perfil en V del nivel internacional es considerablemente m&aacute;s cerrado que el de los niveles deportivos inferiores. </p><p><strong>Palabras clave</strong>: ansiedad; competencia percibida; decisi&oacute;n; deporte colectivo; pericia deportiva. </p><p><strong>Abstract</strong> </p><p align="justify">Decision making in sport has been studied as a kind of cognitive skill. This study has been developed from a motivacional and emotional point of view and this question has received little attention in the scientific literature. It was applied the Decision Making Style Questionnaire-CETD (Ruiz y Graupera, 2005) that assess three scales: Perceived Decisional Competence, Anxiety and Strain to Decide and Commitment for learning how to decide. One hundred and twenty one voleyball players participated (76 female and 45 male) of differente level of expertise: State, National and International. Results showed that the scales of this questionnaire had good reliability when it was applied to specific sport samples. Male and female volleyball players had a similar decisional profile (there were no significant differences), with a moderate selfperception of decisional competence, low level of anxiety and high commitment (V profile). As competence increased, moderately increased the level of commitment and selfperception of decisional competence, too, and decreased the level of anxiety. As a consequence, the decisional profile of the International Group was very different from the rest of the two groups of lower competence. </p><p><strong>Key words</strong>: anxiety; perceived competence; decision; team sport; sport expertise.</p

Molecular structure of one-electron diatomic molecules subject to plasma screening and its e ect on the dynamics

ABSTRACT: The effect of plasma screening on the electronic and vibrational structure of one-electron diatomic molecules is analyzed by including screened Coulomb interactions among all their particles in the solution of the Schrodinger equation. The breakdown of the well-known separability of the Schrodinger equation in confocal elliptical coordinates, the lost of long-range Coulomb interaction and the non-degeneracy in both the united atom and separated atom limits bring new elements into the analysis of the modified binding energies (electronic and vibrational), adiabatic correlation rules, molecular Stark mixings due to polarization effects, unexpected presence of molecular shape resonances and changes in non-adiabatic and radiative couplings upon the variation of the screening strength

La filosofía política de Antonio Negri. Marx en y contra el Imperio

El texto propone una aproximación a los conceptos fundamentales de la arquitectura política negriana, siempre ocupada en pensar la manera de sustraer la potencia al poder, atenta a la transversalidad del gesto marxiano que la recorre: aquel que subraya la interdependencia entre el sentido de una teoría y la praxis con la que se corresponde, el más propio de una ontología del ser social, encaminada a mostrar, no demostrar, las posibilidades de superación del capitalismo a partir de una filosofía de lo actual. En este sentido, el análisis señala la deuda de Antonio Negri con el pensamiento operaísta y sus afinidades con algunos planteamientos de Foucault y Althusser, entendiendo que resultan fundamentales en la reformulación de su leitmotiv: la potencia, ahora es entendida como potencia biopolítica de la multitud de los pobres, enfrentada al poder, que ahora es entendido como biopoder imperial

Hunger and sustainability

This paper examines the problem of world hunger and discusses potential solutions to it. It reflects on the debate about whether transgenic foods should be used, which is more of a social controversy than a scientific one. Sustainability is considered a key driver for innovation that can be used as a basis for assessing the problem of hunger in the world, and the question is inseparable from its ethical aspects. Given that economic growth does not directly equate to human development, this paper states that it is necessary to address the problem of poverty and hunger from the capacity development framework according to human rights. Poverty causes disability by limiting human development; it creates the conditions for the violation of human rights; therefore, an institutional framework and social initiatives aimed at protecting the poor should be established. Finally, the main lines of research in the field of biotechnology are outlined, such as the development of genetically modified organisms and the need to continue defining methods, based on the development of capabilities. Such capabilities should be embedded in educational programmes, to establish guidelines that are incorporated into curricula as transversal orientations to be able to make sustainability a social reality

Effect of potential screening on the H2 autoionizing states

ABSTRACT: We study the behavior of autoionizing states of the hydrogen molecule subject to screened Coulomb interactions using an ab initio Feshbach configuration interaction method. Special attention is given to the algorithms developed for the evaluation of (i) screened molecular orbitals expressed in terms of one-center expansions using B-spline polynomial basis functions and (ii) screened two-electron integrals between configurations expressed in terms of such molecular orbitals, by solving the screened Poisson equation. As an illustration of the method we focus on the lowest Feshbach resonance of the Q1 1+g series of doubly excited states of H2, which lies between the first H2 + (1sσg) and the second H2 + (2pσu) ionization thresholds. We show that Coulomb screening in the electron-proton interaction and between electrons may significantly alter the resonance position and autoionizing decay as a function of internuclear distance. In general, screening increases the resonance lifetime. However, when electron-proton screening dominates over electron-electron screening, we find that the Q1 resonance acquires a pronounced shape-resonance character at internuclear distances where the resonance approaches the lower ionization threshold, thus leading to a pronounced decrease of its lifetime

Complete Feshbach-type projection method to compute autoionizing states in Li-like atomic systems

ABSTRACT: A fully ab initio method of solution to compute autoionizing states in Li-like atomic systems based on the application of the Feshbach projection formalism is proposed. Applications of the Feshbach formalism, which in principle is a complete many-particle theory, to systems of more than two-active electrons are very scarce due to the limitations imposed by the practical construction of correct projection operators P and Q inherent to the theory. We include rigorously all the ingredients required by the Feshbach theory in order to compute accurate resonance parameters for the lowest autoionizing states of Li and Ne7+, for the 2Se, 2Po and 2De symmetries

First Triassic tetrapod (Sauropterygia, Nothosauridae) from Castilla y León: evidence of an unknown taxon for the Spanish record

Several vertebrae of a sauropterygian specimen have been recovered in Fuencaliente de Medinaceli (Soria Province, Castilla y León, Spain). The remains come from Middle–Upper Triassic Muschelkalk Facies. This finding represents the first documented evidence of a Triassic tetrapod in Castilla y León. The vertebrae belong to Nothosaurus, a sauropterygian genus found in Europe, Middle East, North of Africa and China. This genus is poorly-known in the Iberian record. The new remains constitute the first evidence of the species Nothosaurus giganteus, or a related taxon, in the Iberian Peninsula. This study reveals the occurrence of at least two species of the sauropterygian Nothosaurus in the Spanish record.Varias vértebras de un ejemplar de sauropterigio han sido encontradas en Fuencaliente de Medinaceli (Provincia de Soria, Castilla y León, España). Los restos provienen de niveles del Triásico Medio tardío (Ladiniense superior) de la parte superior de las Facies Muschelkalk. Estos elementos representan la primera evidencia documentada de un tetrápodo triásico en Castila y León. Las vértebras pertenecen a Nothosaurus, un género de sauropterigio encontrado en Europa, Oriente Próximo, el norte de África y China. Este género es mal conocido en el registro ibérico. Los nuevos restos constituyen la primera evidencia de la especie Nothosaurus giganteus, o de un taxón emparentado, en la Península Ibérica, siendo atribuidos a Nothosaurus cf. giganteus. Este estudio revela la presencia de, al menos, dos especies diferentes de Nothosaurus en el registro ibérico

Els vertebrats de la Formació Argiles de Morella (Aptià inferior, Cretaci Inferior)

La Formació Argiles de Morella és una de les formacions del Cretaci Inferior peninsular que més registre fòssil de vertebrats està aportant. La seva condició de medis deposicionals, generalment continentals, però també de vegades transicionals amb influències mareals, fa que les restes de la fauna de vertebrats que s’ha localitzat als diversos nivells d’aquesta Formació, siguin principalment d’origen terrestre però també d’origen marí. Així entre la fauna terrestre destaquen per damunt de tot les restes de diversos grups de dinosaures mentre que, de la fauna marina, podríem destacar sobretot materials fòssils que pertanyen al grup dels plesiosaures. No obstant la varietat faunística recuperada és més ampla, amb peixos, amfibis, tortugues, escamosos, cocodrils i pterosaures. Tots junts generen un conjunt de vertebrats que representen una gran part dels tàxons que s’han descrit fins ara en la biota terrestre de l’Aptià inferior, no sols de la Península Ibèrica, sinó de la resta del continent europeu. The vertebrates from Argiles de Morella Formation (Early aptian, Early Cretaceous) One of the most relevant Iberian Lower Cretaceous Formations is the Argiles de Morella Formation. Most of the vertebrate fauna recorded from the distinct beds of this Formation are related with continental environments, but some remains are close related with marine environments. Among the continental fauna highlights the remains of a great variety of dinosaurian groups, whereas plesiosaurian are the most common among marine fauna. Nevertheless, a great variety of other vertebrates such as fishes, amphib·ians, turtles, lizards, crocodiles and pterosaurs have been recorded in beds of this Formation too. This assemblage of vertebrate remains represents one of the most complete records of early Aptian terrestrial biota from Europ

Two-temperature model of the coronal irradiated pellets

A two electron-temperature, quasi-steady model of the corona of a laser-ablated pellet is considered. Ablation pressure, critical radius and mass flow rate are determined. Results are close to those obtained with heat flux saturation well below the free-streaming limit