Search results for "TRANSITIONS"
showing 10 items of 251 documents
On critical properties of the Berry curvature in the Kitaev honeycomb model
2019
We analyse the Kitaev honeycomb model, by means of the Berry curvature with respect to Hamiltonian parameters. We concentrate on the ground-state vortex-free sector, which allows us to exploit an appropriate Fermionisation technique. The parameter space includes a time-reversal breaking term which provides an analytical headway to study the curvature in phases in which it would otherwise vanish. The curvature is then analysed in the limit in which the time-reversal-symmetry-breaking perturbation vanishes. This provides remarkable information about the topological phase transitions of the model. The Berry curvature in itself exhibits no singularities at criticality, nevertheless it distingui…
Luminescence from nearly isolated surface defects in silica nanoparticles
2015
A structured emission/excitation pattern, proper of isolated defects, arises in a vacuum from silica nanoparticles. The luminescence, centered around 3.0-3.5 eV, is characterised by a vibronic progression due to the phonon coupling with two localised modes of frequency ∼1370 cm(-1) and ∼360 cm(-1), and decays in about 300 ns at 10 K. On increasing the temperature, the intensity and the lifetime decrease due to the activation of a non-radiative rate from the excited state. Concurrently, the temperature dependence of the lineshape evidences the low coupling with non-localised modes of the matrix (Huang-Rhys factor S ~ 0.2) and the poor influence of the inhomogeneous broadening. These findin…
Electric-field-controlled reversible order-disorder switching of a metal tip surface
2018
While it is well established that elevated temperatures can induce surface roughening of metal surfaces, the effect of a high electric field on the atomic structure at ambient temperature has not been investigated in detail. Here we show with atomic resolution using in situ transmission electron microscopy how intense electric fields induce reversible switching between perfect crystalline and disordered phases of gold surfaces at room temperature. Ab initio molecular dynamics simulations reveal that the mechanism behind the structural change can be attributed to a vanishing energy cost in forming surface defects in high electric fields. Our results demonstrate how surface processes can be d…
Grain Boundary Wetting Phenomena in High Entropy Alloys Containing Nitrides, Carbides, Borides, Silicides, and Hydrogen: A Review
2021
This review was written during the preparation of M-era.Net full proposal “Grain boundaries in multicomponent alloys without principal component” (A.Ko., A.Ku., G.L., and E.R., application No 9345). We also acknowledge the support of the KIT-Publication Fund of the Karlsruhe Institute of Technology. The Institute of Solid State Physics, University of Latvia, as a center of excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement no. 739508, project CAMART2.
The Birth of a New Nordic Career Guidance Journal
2020
Welcome to the first issue of the Nordic Journal of Transitions, Careers and Guidance (NJTCG), a new international forum for the growing body of research in the Nordic region. Resume Velkommen til forste udgave af Nordic Journal of Transitions, Careers and Guidance (NJTCG), et nyt internationalt forum for en stodt stigende publicering af forskning om indenfor overgange, karriere og vejledning i Norden. Abstrakti Nordic Journal of Transitions, Careers and Guidance (NJTCG) on uusi kansainvalinen julkaisufoorumi kasvavalle pohjoismaiselle ohjausalan tutkimukselle. Tervetuloa ensimmaisen numeron pariin. Utdrattur Velkomin, og takk fyrir innlitið i fyrsta hefti Nordic Journal of Transitions, Car…
La responsabilidad social de las universidades a través de la memoria cinematográfica
2013
[ES] Este artículo rescata una interesante película británica filmada en 1983 por Lewis Gilbert, "Educando a Rita", referencia fiel a la memoria de los inicios de la Open University, a su espíritu de innovación educativa, pionera en la educación universitaria a distancia en Europa. La cinta explora temas relevantes relativos a la educación superior y susceptibles de análisis en al menos cuatro dimensiones: la cultura de la institución universitaria, la profesionalidad docente, la metodología de enseñanza y el papel del alumnado en los estudios superiores. Las dimensiones consideradas requieren de un elemento posibilitador, de reflexión curricular: la orientación de los planes de estudio. El…
A Brief Review of the Effects of Pressure on Wolframite-Type Oxides
2018
In this article, we review the advances that have been made on the understanding of the high-pressure (HP) structural, vibrational, and electronic properties of wolframite-type oxides since the first works in the early 1990s. Mainly tungstates, which are the best known wolframites, but also tantalates and niobates, with an isomorphic ambient-pressure wolframite structure, have been included in this review. Apart from estimating the bulk moduli of all known wolframites, the cation–oxygen bond distances and their change with pressure have been correlated with their compressibility. The composition variations of all wolframites have been employed to understand their different structural phase …
Transitions to Working Life: Securing Professional Competence
2014
This chapter examines the transition from education to work as a critical phase of professional career and the development of professional competence Literature on transition to working life has identified several challenges that many graduates meet in the early stages of their career such as: threat of unemployment, inadequate knowledge and skills, decreased self-efficacy and increased stress, instability of professional identity, newcomers’ role and position in a work community, early attrition and changing occupation. The importance of workplace learning in supporting graduates as they transit to the workplace is influential in assisting graduates deal with these challenges. This chapter…
Collisional effects on spectral line shape from the Doppler to the collisional regime: A rigorous test of a unified model
2000
International audience; The paper presents high resolution Raman investigations of the Q(1) line of H-2 in Ar mixture from low density (Doppler regime) to high density (collisional regime) analyzed with a unique line shape profile. Measurements are performed by stimulated Raman gain spectroscopy between 300 and 1000 K in a wide density range (from 0.2 to 11 amagat). All the observed spectral features are accurately described by a unified model recently proposed by two of the authors. This model accounts for a velocity-memory process, not restricted to the usual hard and soft limits. It also includes correlation between velocity- and phase-changing collisions. An exhaustive analysis of vario…