Search results for "magic"
showing 10 items of 160 documents
Synthesis, structure and properties of N-acetylated derivatives of methyl 5-amino-1H-[1,2,4]triazole-3-carboxylate.
2004
Methyl 5-amino-1H-[1,2,4]triazole-3-carboxylate hydrochloride (1). and free ester (2). were obtained and 2 was reacted with Ac(2)O to give the acetylated products 3-6. Compounds 1-6 were studied using HPLC, GC-MS, FTIR and multinuclear NMR spectroscopy, including the cross-polarisation magic angle spinning (CPMAS) technique. The results of the acetylation of 2 were compared to those of the acetylation of 5-amino-1H-[1,2,4]triazole, and for 2 a significant decrease in the susceptibility to acetylation was found. The reaction of 2 with Ac(2)O at 20 degrees C, regardless of the amount and the concentration of the latter, including neat Ac(2)O, proceeds fully regioselectively and leads to one p…
"Ognuno per sé e Dio contro tutti!". Ricordi di Werner Herzog in Sicilia
2012
Il testo rievoca alcuni momenti del primo soggiorno in Sicilia di Werner Herzog, per la regia di una nuova produzione del "Flauto magico" di Mozart al Teatro Massimo Bellini di Catania (dicembre 1991). In particolare, vengono poste in rilievo la concezione registica di Herzog e il suo approccio al capolavoro mozartiano.
Unraveling the packing pattern leading to gelation using SS NMR and X-ray diffraction: direct observation of the evolution of self-assembled fibers
2010
A detailed understanding of the mode of packing patterns that leads to the gelation of low molecular mass gelators derived from bile acid esters was carried out using solid state NMR along with complementary techniques such as powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and polarizing optical microscopy (POM). Solid state 13C{1H} cross polarization (CP) magic angle spinning (MAS) NMR of the low molecular mass gel in its native state was recorded for the first time. A close resemblance in the packing patterns of the gel, xerogel and bulk solid states was revealed upon comparing their 13C{1H}CPMAS NMR spectral pattern. A doublet r…
Evidence for a spin-aligned neutron-proton paired phase from the level structure of (92)Pd
2011
4 páginas, 4 figuras.-- El Pdf es la versión pre-print.-- et al.
Unexpectedly large charge radii of neutron-rich calcium isotopes
2016
Despite being a complex many-body system, the atomic nucleus exhibits simple structures for certain "magic" numbers of protons and neutrons. The calcium chain in particular is both unique and puzzling: evidence of doubly-magic features are known in 40,48Ca, and recently suggested in two radioactive isotopes, 52,54Ca. Although many properties of experimentally known Ca isotopes have been successfully described by nuclear theory, it is still a challenge to predict their charge radii evolution. Here we present the first measurements of the charge radii of 49,51,52Ca, obtained from laser spectroscopy experiments at ISOLDE, CERN. The experimental results are complemented by state-of-the-art theo…
State of the art of CPMAS 13C-NMR spectroscopy applied to natural organic matter
2004
A number of different techniques are presently available for characterizing humified natural organic matter (NOM). Carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) in the solid state using cross-polarization (CP) and magic angle spinning (MAS) represents the most powerful experimental approach used to collect direct information on the structural and conformational characteristics of humic carbon backbones. Despite the problems due to the presence of paramagnetic impurities and the generally low organic matter concentration, cross-polarization magic angle spinning 13C-NMR spectroscopy (CPMAS 13C-NMR) is applied in soil chemistry and geochemistry mainly because of its relevance in …
Charge radii of neon isotopes across the sd neutron shell
2011
We report on the changes in mean square charge radii of unstable neon nuclei relative to the stable Ne-20, based on the measurement of optical isotope shifts. The studies were carried out using collinear laser spectroscopy on a fast beam of neutral neon atoms. High sensitivity on short-lived isotopes was achieved thanks to nonoptical detection based on optical pumping and state-selective collisional ionization, which was complemented by an accurate determination of the beam kinetic energy. The new results provide information on the structural changes in the sequence of neon isotopes all across the neutron sd shell, ranging from the proton drip line nucleus and halo candidate Ne-17 up to the…
Independent yields of neutron-rich nuclei in charged-particle induced fission
1997
Abstract Yields of fission products have been studied at the recently upgraded IGISOL facility in Jyvaskyla using 50 MeV H2+ beam (Ep = 25 MeV) and thin natTh and natU targets. The independent yields of fission products in the mass regions A = 99−112 (elements Y, Nb and Tc) and A = 127−134 (elements Sn, Sb and Te) have been obtained. Comparisons of the experimental isotopic distributions with theoretical ones are presented. Enhancement of the production rate of the doubly magic 132Sn is observed in the experimental yield curve.
Radioactive ion beams in the region of 100Sn and 78Ni at the NSCL
2004
The regions around the doubly magic nuclei 100 Sn and 78 Ni are of great interest from a nuclear structure standpoint. These nuclei also play a key role in the astrophysical rp- and r-processes, respectively. Recently, nuclei in these regions were studied at the Coupled Cyclotron Facility at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University.
Optiskā simbolu atpazīšana čekos un pavadzīmēs.
2018
Mūsdienu digitizācijas un straujo tehnoloģiju ietekmē dažādu sfēru uzņēmumi steidz optimizēt un vienkāršot savu ikdienu, integrējot tajā pieejamos tehnoloģiskos risinājumus, lai spētu efektīvāk plānot laiku un būt konkurētspējīgi. Tā kā čeku un pavadzīmju apstrāde var būt laikietilpīgs process, tad pēc autora domām optiskās simbolu atpazīšanas sniegtās iespējas varētu būt viens no variantiem kā vienkāršot šo procesu. Galvenais mērķis ir pārliecināties, vai ar brīvi pieejamiem atvērtā pirmkoda risinājumiem ir iespējams veikt simbolu atpazīšanu, lai paātrinātu dokumentu apstrādi. Darba gaitā tiek pētīta optiskā simbolu atpazīšana…