13,783 research outputs found

    Qualitative and quantitative analysis of mixtures of compounds containing both hydrogen and deuterium

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    Method allows qualitative and quantitative analysis of mixtures of partially deuterated compounds. Nuclear magnetic resonance spectroscopy determines location and amount of deuterium in organic compounds but not fully deuterated compounds. Mass spectroscopy can detect fully deuterated species but not the location

    En deute amb Estellés

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    Cosmic dust

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    Dust is a ubiquitous component of our galaxy and the solar system. The collection and analysis of extraterrestrial dust particles is important to exobiology because it provides information about the sources of biogenically significant elements and compounds that accumulated in distant regions of the solar nebula and that were later accreted on the planets. The topics discussed include the following: general properties of interplanetary dust; the carbonaceous component of interplanetary dust particles; and the presence of an interstellar component

    Gate Oxide Reliability and Deuterated CMOS Processing

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    In recent literature, a controversy has arisen over the question whether deuterium improves the stability of the MOS gate dielectric. It appears as if this controversy finds its origin in the different stages (e.g. oxidation or post metal anneal) deuterium is introduced in the CMOS process. This paper investigates this in detail. The obtained results show that the hot carrier degradation only benefits from an isotope effect when deuterium is introduced in the post metal anneal. At the same time, charge to breakdown for high quality oxides does not benefit from an isotope effect, regardless of the processing stage deuterium is introduced, or the gate oxide thickness used. This is verified on two different sets of wafers fabricated in two different laboratories

    Defect-related versus excitonic visible light emission from ion beam synthesized Si nanocrystals in SiO2

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    Two sources of room temperature visible luminescence are identified from SiO2 films containing ion beam synthesized Si nanocrystals. From a comparison of luminescence spectra and photoluminescence decay lifetime measurements between Xe + -implanted SiO2 films and SiO2 films containing Si nanocrystals, a luminescence feature attributable to defects in the SiO2 matrix is unambiguously identified. Hydrogen passivation of the films selectively quenches the matrix defect luminescence, after which luminescence attributable to Si nanocrystals is evident, with a lifetime on the order of milliseconds. The peak energy of the remaining luminescence attributable to Si nanocrystals ``redshifts'' as a function of different processing parameters that might lead to increased nanocrystal size and the intensity is directly correlated to the formation of Si nanocrystals. Upon further annealing hydrogen-passivated samples at low temperatures (< 500 ¬įC), the intensity of nanocrystal luminescence increases by more than a factor of 10

    La crisi del deute a Europa

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    El deute a Canet al segle XVII

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    A possible deuterium anomaly: Implications of the CH3D/CH4 mixing ratios in the atmospheres of Jupiter, Saturn, and Uranus

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    Observations of CH3D in the atmospheres of the outer planets provide a test of the theory of deuterium fractionation equilibrium in the formation and evolution of these planets. Recent measurements of the CH3D/CH4 mixing ratios made for Saturn and Uranus are presented and intercompared with current values of Jupiter, illustrating large differences between the planets. Their implied D/H ratios are compared to D/H ratios derived from measurements of HD/H2; and, in the cases of Jupiter and Saturn, they may be incompatible. Implications of these comparisons are discussed in terms of the deuterium fractionation chemistry and possible enrichments of deuterium in the core ices of the planets

    El deute exterior mallorquí. Els creditors catalans a partir de l'estudi d'un capbreu de censals del segon quart del segle XV

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    (CAT) L'estudi d'un capbreu de censals manat confeccionar a finals del regnat d'Alfons el Magn√†nim, no nom√©s permet calibrar amb m√©s precisi√≥ quin va ser el volum real del deute contret pel municipi mallorqu√≠ a Catalunya, sin√≥ tamb√© con√®ixer el nivell de participaci√≥ dels diferents grups socials en aquesta deute extern i tenir identificats els principals creditors catalans. Aquesta font tamb√© permet apreciar els resultats obtinguts de cara a l'efectiva disminuci√≥ del pes d'aquest deute, a partir de les mesures preses en la Conc√≤rdia de Barcelona de 1431.(ESP) El estudio de un capbreu de censals mandado confeccionar a finales del reinado de Alfonso el Magn√°nimo, no s√≥lo permite calibrar con mayor precisi√≥n cu√°l fue el volumen real de la deuda contra√≠da por el municipio mallorqu√≠n en Catalu√Īa, sino tambi√©n conocer el nivel de participaci√≥n de los distintos grupos sociales en esa deuda externa y tener identificados a los principales acreedores catalanes. Dicha fuente tambi√©n permite apreciar los resultados obtenidos de cara a la efectiva disminuci√≥n del peso de esa deuda, a partir de las medidas tomadas en la Concordia de Barcelona de 1431.(EN) An analysis of a capbreu de censals (an inventory of perpetual annuities), drafted on request towards the end of Alfonso V‚Äôs reign, not only allows us to gauge more accurately the real extent of the debt contracted by the Majorcan municipality in Catalonia, but it also indicates different social groups‚Äô degree of involvement in this external debt, together with the full identification of the main Catalan creditors. This source of information also enables us to appreciate the results of attempts to reduce the debt, thanks to measures adopted at the Concordia de Barcelona in 1431.Peer reviewe
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