Search results for "COPI"
showing 10 items of 2618 documents
Indoor pollutant identification by means of spectroscopic techniques
1995
Spectroscopie des hexafluorures à nombre impair d'électrons
1995
From a theoretical point of view, a tensorial formalism adapted to the study of molecules or octahedral ions with a half-integer angular momentum has been developed for the first time. We have used here the method of projective representations, more consistent than that of double groups. A complete set of coupling coefficients and formulas, as well as the corresponding computing programs have been elaborated. This has firstly allowed to write a simple model describing the vibronic structure of colored hexafluorides. Then, somme applications of this formalism to the study of rovibronic couplings of XY6 molecules in a fourfold degenerate electronic state have been considered, especially conce…
Spectroscopic studies of semiconducting single-walled carbon nanotubes
2010
The unique nature of optical properties of single-walled carbon nanotubes (SWCNT), together with their promising potential applications, have created enormous interest towards the photophysics of SWCNT. Many aspects of carbon nanotubes originate from the electronic structure of carbon honeycomb lattice and one-dimensionality. SWCNTs exist in various chiral structures and diameters, which the optical and electrical properties are dependent on. It has been discovered that SWCNT excited states are excitonic with strong Coulomb interaction between the electron and the hole. However, many features of excitons are not yet well defined, such as absorption cross-sections, fluorescence quantum yield…
Materia e Luce, Contributi alla Scuola Permanente per l’Aggiornamento degli Insegnanti di Scienze - SPAIS V edizione
2013
Remodeling Pattern of Spinal Canal after Full Endoscopic Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: One Year Repe…
2022
Objective: There is limited literature on repetitive postoperative MRI and clinical evaluation after Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. Methods: Clinical visual analog scale, Oswestry Disability Index, McNab’s criteria evaluation and MRI evaluation of the axial cut spinal canal area of the upper end plate, mid disc and lower end plate were performed for patients who underwent single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. From the evaluation of the axial cut MRI, four types of patterns of remodeling were identified: type A: continuous expanded spinal canal, type B: restenosis with delayed expansio…
Three-dimensional skyrmions in spin-2 Bose–Einstein condensates
2017
We introduce topologically stable three-dimensional skyrmions in the cyclic and biaxial nematic phases of a spin-2 Bose-Einstein condensate. These skyrmions exhibit exceptionally high mapping degrees resulting from the versatile symmetries of the corresponding order parameters. We show how these structures can be created in existing experimental setups and study their temporal evolution and lifetime by numerically solving the three-dimensional Gross-Pitaevskii equations for realistic parameter values. Although the biaxial nematic and cyclic phases are observed to be unstable against transition towards the ferromagnetic phase, their lifetimes are long enough for the skyrmions to be imprinted…
Coronal properties of active G-type stars in different evolutionary phases
2005
We report on the analysis of XMM-Newton observations of three G-type stars in very different evolutionary phases: the "weak-line" T Tauri star HD 283572, the Zero Age Main Sequence star EK Dra and the Hertzsprung-gap giant star 31 Corn. The X-ray luminosities of the three stars are all in the range 10(30) - 10(31) erg/s. We compare the Emission Measure Distributions of these bright sources, derived from high-resolution X-ray spectra, as well as the pattern of elemental abundances vs. First Ionization Potential (FIP). The results of our analysis suggest that the coronae of these stars are very similar in terms of dominant coronal magnetic structures, in spite of differences in their evolutio…
Stochastic gravito-inertial modes discovered by CoRoT in the hot Be star HD 51452
2012
International audience; Context. Be stars are rapidly rotating stars with a circumstellar decretion disk. They usually undergo pressure and/or gravity pulsation modes excited by the κ-mechanism, i.e. an effect of the opacity of iron-peak elements in the envelope of the star. In the Milky Way, p-modes are observed in stars that are hotter than or equal to the B3 spectral type, while g-modes are observed at the B2 spectral type and cooler. Aims. We observed a B0IVe star, HD 51452, with the high-precision, high-cadence photometric CoRoT satellite and high-resolution, ground-based HARPS and SOPHIE spectrographs to study its pulsations in great detail. We also used the lower resolution spectra a…
Uso de las coronas telescópicas en el tratamiento de un paciente adulto con fisura labiopalatina: Puesta al día de la etiología y el tratamiento
2006
La fisura labiopalatina es una de las malformaciones congénitas craneofaciales más importantes a tener en cuenta por el odontólogo general debido a su alta incidencia y a su elevada repercusión en la cavidad oral. Sus causas se deben a factores genéticos y predominantemente a factores ambientales, haciendo su aparición ya en el período embrionario. El sexo masculino se encuentra más afectado, en una relación de 7:3. La asociación más frecuente es el labio leporino unilateral total con fisura palatina, que es el caso que nos atañe. Presentamos el caso de un varón de 20 años que acude a nuestra consulta demandando una solución estética a su situación dental. El tratamiento efectuado al pacien…
Stresa pārvārēšanas stratēģiju saistība ar subjektīvo labklājību un pašcieņu
2017
Pētījuma mērķis ir izpētīt stresa pārvārēšanas stratēģiju, subjektīvās labklājības un pašcieņas savstarpējās saistības. Pētījumā piedalījās 86 respondenti, vecumā no 18 līdz 41 gadam. Pašcieņas mērīšanai tika izmantota Rozenberga pašcieņas skala (Rosenberg self-esteem scale, (Rosenberg, 1965)), Latvijā adaptējusi Anika Miltuze, 1996.gadā; stresa pārvārēšanas stratēģiju mērīšanai - Stresa pārvarēšanas stratēģiju aptauja (The Coping Orientation of Problem Experience / COPE / Inventory, (Carver, Scheier, & Weintraub, 1989)), Latvijā adaptējusi Inna Petrova, 2009.gadā; un subjektīvās labklājības mērīšanai - skala “ Apmierinātība ar dzīvi” (Satisfaction With Life Scale; (Pavot, & Diener, 1993)).…