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Cyclopropenylidene,, is a simple hydrocarbon, ubiquitous in astrophysical gases, and possessing a permanent electric dipole moment. Its readily observed multifrequency rotational transitions make it an excellent probe for the physics and history of interstellar matter. The collisional properties of with He are presented here. We computed the full Potential Energy Surfaces, and we perform quantum scattering in order to provide rates of quenching and excitation for low to medium temperature regimes. We discuss issues with the validity of the usual Local Thermodynamical Equilibrium assumption, and also the intricacies of the spectroscopy of an asymmetric top. We present the wide range of actual critical densities, as recently observed.
Euclid is a Europe-led cosmology space mission dedicated to a visible and near infrared survey of the entire extra-galactic sky. Its purpose is to deepen our knowledge of the dark content of our Universe. After an overview of the Euclid mission and science, this contribution describes how the community is getting organized to face the data analysis challenges, both in software development and in operational data processing matters. It ends with a more specific account of some of the main contributions of the Swiss Science Data Center (SDC-CH).
Astrocytes constitute a major group of glial cells which were long regarded as passive elements, fulfilling nutritive and structural functions for neurons. Calcium rise in astrocytes propagating to neurons was the first demonstration of direct interaction between the two cell types. Since then, calcium has been widely used, not only as an indicator of astrocytic activity but also as a stimulator switch to control astrocyte physiology. As a result, astrocytes have been elevated from auxiliaries to neurons, to cells involved in processing synaptic information. Curiously, while there is evidence that astrocytes play an important role in synaptic plasticity, the data relating to calcium's pivotal role are inconsistent. In this review, we will detail the various mechanisms of calcium flux in astrocytes, then briefly present the calcium-dependent mechanisms of gliotransmitter release. Finally, we will discuss the role of calcium in plasticity and present alternative explanations that could reconcile the conflicting results published recently.
What governs the first entrance to the territory of a member state by a third country national who is a family-member of a European citizen who has migrated to that member state: (secondary) Community law or national law? This question, of the utmost constitutional importance as it regards the power to decide on the entrance of foreigners on national territory, one of the pearls in the crown of traditional national sovereignty, was facing the Court of Justice of the European Communities in the case of Yunying Jia v. Migrationsverket. Earlier the Court had sent out different signals. Now, in the long-awaited and remarkably short full Court decision of 9 January 2007, the Court carefully manoeuvred between Scylla (the member states are in full control) and Charybdis (Community law decides all): a member state is not required to make the grant of a residence permit to a third country national subject to the condition of lawful residence in a member state – but it apparently may do so. It is quite unlikely that this judgment once and for all settles the question.
Nous dérivons les dynamiques de l'inflation issues des différentes
hypothèses d'ajustement des prix rencontrées dans la littérature
néo-keynésienne. Pour chaque modèle nous calculons la réponse de l'inflation
et du produit suite à un choc sur le taux de croissance de la masse
monétaire. Nous constatons que seules deux modélisations reproduisent
correctement certains faits stylisés importants concernant l'impact de ce
type de choc monétaire : la première est la spécification avec prix
prédéterminés de Mankiw et Reis (2002) et la seconde celle à prix fixes de
Galí et Gertler (1999). Aucune des autres alternatives examinées, y compris
le modèle à prix fixes de Fuhrer et Moore (1995), ne génère de réponse
satisfaisante. Elles sont notamment toutes incapables de reproduire une
persistance suffisante de l'inflation. Ceci montre que dans les modèles à
prix fixes, la structure de rigidité choisie im-porte autant pour le degré
de persistance de l'inflation que la présence ou non de valeurs retardées de
l'inflation dans la dynamique.
Comparative studies have been carried out on the cathodoluminescence (CL) and photoluminescence (PL) properties of GaN implanted with Tm and GaN co-implanted with Tm and a low concentration of Er. Room temperature CL spectra were acquired in an electron probe microanalyser to investigate the rare earth emission. The room temperature CL intensity exhibits a strong dependence on the annealing temperature of the implanted samples. The results of CL temperature dependence are reported for blue emission (∼ 477 nm) which is due to intra 4f-shell electron transitions (1G4 → 3H6) associated with Tm3+ ions. The 477 nm blue CL emission is enhanced strongly as the annealing temperature increases up to 1200°C. Blue PL emission has also been observed from the sample annealed at 1200°C. To our knowledge, this is the first observation of blue PL emission from Tm implanted GaN samples. Intra-4f transitions from the 1D2 level (∼ 465 nm emission lines) of Tm3+ ions in GaN have been observed in GaN:Tm films at temperatures between 20–200 K. We will discuss the temperature dependent Tm3+ emission in both GaN:Tm,Er and GaN:Tm samples.
CuInSe2 and Cu(In, Ga)Se2 precursor layers have been prepared by electrodeposition, with morphologies suitable for device completion. These precursor films were transformed into photovoltaic quality films after thermal annealing without any post-additional vacuum deposition process. Depending on the preparation parameters annealed films with different band gaps between 1eV and 1.5 eV have been prepared. The dependence of resulting solar cell parameters has been investigated. The best efficiency achieved is about 10,2 % for a band gap of 1.45 eV. This device presents an open circuit voltage value of 740 mV, in agreement with the higher band gap value. Device characterisations (current-voltage, capacitance-voltage and spectral response analysis) have been performed. Admittance spectroscopy at room temperature indicates the presence of two acceptor traps at 0.3 and 0.43 eV from the valance band with density of the order of 2. 1017 cm-3 eV-1.
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