705 research outputs found
The Ferromagnetism in the Vicinity of Lifshitz Topological Transitions
We show that the critical temperature of a ferromagnetic phase transition in
a quasi-two-dimensional hole gas confined in a diluted magnetic semiconductor
quantum well strongly depends on the hole chemical potential and hole density.
The significant variations of the the Curie temperature occur close to the
Lifshitz topological transition points where the hole Fermi surface acquires
additional components of topological connectivity due to the filling of excited
size-quantization subbands. The model calculations demonstrate that the Curie
temperature can be doubled by a small variation of the gate voltage for the
CdMnTe/CdMgTe quantum well based device
THE IMAGE OF SOCIALLY ACTIVE INDIVIDUAL IN THE REPRESENTATIONS OF STUDENT YOUTH
The study of students’ representations of a socially active individual is one of the major tasks of psychology of education. The purpose of the study is to carry out analysis of characteristics of an image of a socially active individual in the representations of student youth and to correlate them with self-assessment of social activity and assessment of real social activity. Students aged 17-23 years (n=251) took part in the study ?=20.11, SD=1.2 (41% men). We used the polling method with the scales developed by the authors of the present study in order to identify self-assessment of social activity, to evaluate real activity; and the associative experiment method. In the study we analysed qualitative and quantitative characteristics of the image of a socially-active individual in the representations of university students. We have established major meaningful characteristics of representations (personal qualities, self-improvement and personal transformation, states, representation in the group, process and activity-related characteristics). Conclusion has been made about the connection between the intensity of students’ social activity and cognitive complexity of the image of a socially active individual and the content of subjective (initiative, confidence) and psychodynamic (vigour) categories in it
Coherent spin dynamics of electrons and holes in CsPbBr perovskite crystals
The lead halide perovskites demonstrate huge potential for optoelectronic
applications, high energy radiation detectors, light emitting devices and solar
energy harvesting. Those materials exhibit strong spin-orbit coupling enabling
efficient optical orientation of carrier spins in perovskite-based devices with
performance controlled by a magnetic field. Perovskites are promising for
spintronics due to substantial bulk and structure inversion asymmetry, however,
their spin properties are not studied in detail. Here we show that elaborated
time-resolved spectroscopy involving strong magnetic fields can be successfully
used for perovskites. We perform a comprehensive study of high-quality
CsPbBr crystals by measuring the exciton and charge carrier -factors,
spin relaxation times and hyperfine interaction of carrier and nuclear spins by
means of coherent spin dynamics. Owing to their "inverted" band structure,
perovskites represent appealing model systems for semiconductor spintronics
exploiting the valence band hole spins, while in conventional semiconductors
the conduction band electrons are considered for spin functionality.Comment: 8 pages, 3 figures + supplementary informatio
Influence of plasma volume discharge in atmospheric-pressure air on the admittance of MIS structures based on MBE p-HgCdTe
This article investigates the effect of a nanosecond plasma volume discharge, which is formed in an inhomogeneous electrical field at atmospheric pressure, on the electrical properties of MIS structures based on HgCdTe (MCT) epitaxial films. The MIS structure based on films exposed to the discharge significantly changed its main parameters. The most notable feature of the structure exposed to discharge is the significant increase in the positive fixed charge in the insulator. A possible reason for changes in the characteristics of MIS structure after exposure to discharge is the significant change in the impurity-defect system of the semiconductor near the interface. This is accompanied with a formation of an insulator film of nanometer thickness on the surface, which gives rise to positive fixed charge
Estimation of the impact of large regional investment projects on the regional development on the example of Universiade-2013
© 2015, Mediterranean Center of Social and Educational Research. All rights reserved. The work reveals and classifies the main socio-economic consequences of large international competitions. The impact of a large international sporting event on the socio-economic development of the host region is characterized with the institutional approach on the example of Universiade 2013 in Kazan. The impact of the Universiade on the socio-economic development in Tatarstan is estimated by economic sectors. In particular, the construction industry, hospitality industry, tourism, education in the Republic of Tatarstan are considered
On bi-integrable natural Hamiltonian systems on the Riemannian manifolds
We introduce the concept of natural Poisson bivectors, which generalizes the
Benenti approach to construction of natural integrable systems on the
Riemannian manifolds and allows us to consider almost the whole known zoo of
integrable systems in framework of bi-hamiltonian geometry.Comment: 24 pages, LaTeX with AMSfonts (some new references were added
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