O universal na selva

Na - O Anticorrelation And HB I . The Na - O anticorrelation in NGC 2808 ⋆

We derived atmospheric parameters and elemental abundances of Fe, O and Na for about 120 red giant stars in the Galactic globular cluster NGC 2808. Our results are based on the analysis of medium-high resolution (R=22000-24000) GIRAFFE spectra acquired with the FLAMES spectrograph at VLT-UT2 as a part of a project aimed at studying the Na-O anticorrelation as a function of physical parameters i...

Vše o češtině na novém portálu

Rozhovor s klimatologem Pavlem Proškem Eurozóna stojí na křižovatce. Import americké finanční krize do Evropy a dlouhodobě problematické vytvoření eurozóny z velké skupiny ekonomicky nehomogenních států odhalilo křehkost celé měnové unie. Ta se teď musí rozhodnout, co bude dál. Martin Kvizda z ekonomicko-správní fakulty tvrdí, že jádro dnešních problémů leží v hospodářské politice 70. let 20. s...

Selva: A New Syntactic Parser for Portuguese

Na Nmr Study of Layered Superconductor Na X Coo 2 · Yh 2 O

We measured 23 Na-NMR spectra and nuclear spin-lattice relaxation rates 23 (1/T1) of superconducting and non-superconducting bilayer hydrate NaxCoO2 · yH2O (x ∼ 0.3, y ∼ 1.3). The central resonance frequency shows a small but various shift due to the difference in the shielding effect by intercalated H2O molecules. The different shielding effect also gives a large difference in the magnitude of...

Na Nmr Study of Non-superconducting Double-layer Hydrate Na X Coo 2 · Yh 2 O

We report Na NMR studies of the polycrystalline samples of double-layer hydrated cobalt oxides NaxCoO2 · yH2O (x ∼035 and y ∼ 1.3) with the superconducting transition temperatures Tc <1.8 K and ∼4.5 K, and the dehydrated NaxCoO2 (x ∼0.35). The hyperfine field and the electric field gradient at the Na sites in the non-hydrated Na0.7CoO2 and the dehydrated Na0.35CoO2 are found to be significantly...