Search results for "general [Kuiper belt]"
showing 10 items of 26518 documents
Многофазные решения нелокальных симметричных редукций уравнений иерархии АКНС: общий анализ и простейшие примеры
2020
Рассмотрены нелокальные симметрии, которыми обладают все или все четные (все нечетные) уравнения из иерархии АКНС. Построены примеры решений, удовлетворяющих одновременно нескольким нелокальным уравнениям из иерархии АКНС. Проведено подробное исследование однофазных решений.
Anwendungen in Hydro- und Aerodynamik
1949
Wie in der Theorie der Hydrodynamik gezeigt wird, konnen die Geschwindigkeitskomponenten der stationaren Stromung einer reibungslosen inkompressiblen Flussigkeit durch Differentiation einer der Laplaceschen Differentialgleichung genugenden Ortsfunktion u (des Geschwindigkeitspotentials) nach den Koordinaten des Aufpunktes erhalten werden. Ist insbesondere die Stromung zweidimensional, d. h. z. B. nur von den rechtwinkligen Koordinaten x und y abhangig, so stellt die zum Geschwindigkeitspotential u (x, y) konjugierte Funktion v (x, y) die sogenannte Stromfunktion dar. Die Kurven u (x, y) = konstant stellen die Niveaulinien, diejenigen v (x, y) = konstant die Stromlinien der betrachteten Stro…
Collisions moléculaires en phase gazeuse
2019
L’étude théorique des collisions entre atomes et molécules permet, grâce à la résolution d’état à état des simulations numériques basées sur la physique quantique, une description détaillée des mécanismes mis en jeu et contribue grandement à améliorer les modèles atmosphériques et astrophysiques. Dans cet article, après avoir présenté les méthodes de dynamique actuelles, nous donnons des exemples clés d’intérêt pour le milieu interstellaire, l’atmosphère terrestre et les milieux (ultra)froids, et présentons les défis majeurs à relever.
Potentialités des lasers à fibre dans la génération de rayonnement cohérent UV
2006
Le premier laser a fibre dope aux ions de terres rares fonctionna au tout debut des annees 60. Il fournissait quelques milliwatts autour de 1 μm. Les decades suivantes virent tres peu d'ameliorations tant du cote des laboratoires que du point de vue industriel. La derniere decennie (1995/2005) vit se concretiser la seconde revolution des lasers a fibres. Deja kilowatt en continu, ils atteignent desormais les 10 13 watts/cm 2 avec des impulsions de la centaine de femtoseconde. Lors de cette presentation nous passerons en revue les potentialites des lasers a fibre. Nous decrirons les verrous technologiques qui ont ete leves ces dix dernieres annees pour les regimes CW mais aussi femtosecondes…
Analysis of the specific common competences of the Degree Courses in Speech Therapy and on the ability to apply in the didactic systems
2020
Law 11 January 2018 n. 3 places the attention of the Health Professions on the specific common skills, which must be evident in the didactic systems to protect the Profession. The purpose of this work is to identify which skills are always present among the training objectives of the Degree Courses in Speech Therapy, and which instead become "specific" for our profession. The data analysis was conducted on 27 Degree Courses in Speech Therapy present in Italy, using the portal "Universitaly" and evaluating the SUA cards of the various Degree Courses. The analysis of the data revealed that: basic skills were insufficient for the areas of labor law and corporate organization; transversal skill…
Optical detection of paramagnetic centres in activated oxyfluoride glass-ceramics
2018
Electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD) and EPR detected via MCD (MCD-EPR) investigations have been performed on rare-earth activated oxyfluoride glasses and glass-ceramics. Er3+, Gd3+, and Mn2+ activators in oxyfluoride glass-ceramics show paramagnetic MCD behaviour and the MCD-EPR has been detected. The results of the MCD-EPR measurements for the Er-doped oxyfluoride glass-ceramics showed that Er3+ ions in the CaF2 crystallites in these ceramics embed only in the cubic symmetry environment, similarly to the previous observations of cubic Gd3+ centres in the glass-ceramics containing CaF2. Finally, the correlation of optics and paramagnetic centres is discu…
Molecular association of cryptand 221D in NaCl-water solutions. A small-angle neutron scattering study
1993
Molecules of 5-Decyl-4,7,13,16,21-pentaoxa-1,10-diaza-bicyclo-[8.8.5.]tricosan (221D) and its sodium complex, with both a hydrophobic and a hydrophilic portion, are expected to form aggregates in water solutions. This was confirmed by surface tension measurements. The aggregation behaviour was studied by small-angle neutron scattering at two different [NaCl]/[221D] molar ratios, such as to obtain, in one case, aggregates entirely made up of ionic monomers, and in the other, mixed micelles constituted by both ionic and non-ionic units. The variation of the aggregation number and number of aggregates indicated that, in the former case, smaller micelles were formed, as a consequence of repulsi…
First principles hybrid Hartree-Fock-DFT calculations of bulk and (001) surface F centers in oxide perovskites and alkaline-earth fluorides
2020
Valuable discussions with E. A. Kotomin are gratefully acknowledged. Research contribution of R. E. and A. I. P. has been performed within the framework of the EUROfusion Enabling Research project: ENR-MFE19.ISSP-UL-02 “Advanced experimental and theoretical analysis of defect evolution and structural disordering in optical and dielectric materials for fusion applications.” The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Savaime sklindančios aukštatemperatūrinės sintezės būdu gautų aliuminio oksinitrido miltelių ir jų keramikų optinės savybės
2021
The reported study was funded by RFBR according to the Research Project No. 19-08-00655. V.P. acknowledges the State Research Program ‘Aug-stas enerģijas fizika un paātrinātāju tehnoloģijas’ (Projekta Nr. VPP-IZM-CERN-2020/1-0002). The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the H2020-WIDESPREAD-01-2016-2017-Teaming Phase2 under Grant Agreement No. 739508, Project CAMART2.
Pressure-induced instability of the fergusonite phase of EuNbO4 studied by in situ Raman spectroscopy, x-ray diffraction, and photoluminescence spect…
2020
In this article, we present high-pressure experimental investigations on EuNbO4, an interesting technologically important material, using synchrotron based x-ray powder diffraction, Raman spectroscopy, and europium photoluminescence measurements up to 39.2, 31.6, and 32.4 GPa, respectively. All three techniques show the stability of the ambient monoclinic phase until 20 GPa. Beyond that, a pressure-induced structural phase transition takes place with the coexistence of two phases over a wide pressure range. The structure of the high-pressure phase has been determined as orthorhombic (space group: Imma) with a volume discontinuity of nearly 9% at the transition indicating the nature of trans…