208 research outputs found
Registration of terahertz irradiation with silicon carbide nanostructures
The response to external terahertz (THz) irradiation from the silicon carbide
nanostructures prepared by the method of substitution of atoms on silicon is
investigated. The kinetic dependence of the longitudinal voltage is recorded at
room temperature by varying the drain-source current in the device structure
performed in a Hall geometry. In the frameworks of proposed model based on the
quantum Faraday effect the incident radiation results in the appearance of a
generated current in the edge channels with a change in the number of magnetic
flux quanta and in the appearance of features in the kinetic dependence of the
longitudinal voltage. The generation of intrinsic terahertz irradiation inside
the silicon carbide nanostructures is also revealed by the
electrically-detected electron paramagnetic resonance (EDEPR) measured the
longitudinal voltage as a function of the magnetic field value.Comment: 11 pages, 6 figure
Terahertz emission from silicon carbide nanostructures
For the first time, electroluminescence detected in the middle and far
infrared ranges from silicon carbide nanostructures on silicon, obtained in the
framework of the Hall geometry. Silicon carbide on silicon was grown by the
method of substitution of atoms on silicon. The electroluminescence from the
edge channels of nanostructures is induced due to the longitudinal drain-source
current. The electroluminescence spectra obtained in the terahertz frequency
range, 3.4, 0.12 THz, arise due to the quantum Faraday effect. Within the
framework of the proposed model, the longitudinal current induces a change in
the number of magnetic flux quanta in the edge channels, which leads to the
appearance of a generation current in the edge channel and, accordingly, to
terahertz radiation.Comment: 10 pages, 9 figure
An algorithm for the integration of information and communication technologies in teaching languages for special purposes (the example of Russian as a foreign language)
This article is dedicated to the integration of information and communication technologies (ICT) in the process of teaching Russian as a foreign language for special purposes at an advanced stage of studying for students of non-linguistic disciplines. Based on many years of teaching experience in a virtual environment, the authors show forms of successful organization of the educational process provide tactics and a strategy for studying using presentations, video lectures and webinars, as well as teaching aids based on the electronic platform MOODLE. The developed algorithm of a mixed model of teaching enables good use of the potential of information and communication tools in the practice of teaching the Russian language for special purposes (economics and finance specializations)
Peculiarities of anharmonic lattice dynamics and thermodynamics of alkaline-earth metals
The calculations are performed for a broad range of the properties of Ca and
Sr in the fcc and bcc phases. A detailed information on the magnitude and
character of temperature dependence of anharmonic effects in the lattice
dynamics over the entire Brillouin zone (frequency shifts and phonon damping,
Gruneisen parameters) is given. A detailed comparison of the computational
results for the heat capacity and thermal expansion with the experimental data
is carried out; the theoretical results are in good agreement with the
experiment.Comment: 16 pages, 19 Postscript figures, Revte
Diaquabis[3-(hydroxyimino)butanoato]nickel(II)
In the neutral, mononuclear title complex, [Ni(C4H6NO3)2(H2O)2], the Ni atom lies on a crystallographic inversion centre within a distorted octahedral N2O4 environment. Two trans-disposed anions of 3-hydroxyiminobutanoic acid occupy four equatorial sites, coordinated by the deprotonated carboxylate and protonated oxime groups and forming six-membered chelate rings, while the two axial positions are occupied by the water O atoms. The O atom of the oxime group forms an intramolecular hydrogen bond with the coordinated carboxylate O atom. The complex molecules are linked into chains along b by hydrogen bonds between the water O atom and the carboxylate O of a neighbouring molecule. The chains are linked by further hydrogen bonds into a layer structure
Diaquabis[3-(hydroxyimino)butanoato]nickel(II): a triclinic polymorph
The title centrosymmetric mononuclear complex, [Ni(C4H6NO3)2(H2O)2], is a polymorph of the previously reported complex [Dudarenko et al. (2010 ▶). Acta Cryst. E66, m277–m278]. The NiII atom, lying on an inversion center, is six-coordinated by two carboxylate O atoms and two oxime N atoms from two trans-disposed chelating 3-hydroxyiminobutanoate ligands and two axial water molecules in a distorted octahedral geometry. The hydroxy group forms an intramolecular hydrogen bond with the coordinated carboxylate O atom. The complex molecules are linked in stacks along [010] by a hydrogen bond between the water O atom and the carboxylate O atom of a neighboring molecule. The stacks are further linked by O—H⋯O hydrogen bonds into a layer parallel to (001)
First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon
We report the first measurement of coherent elastic neutrino-nucleus
scattering (\cevns) on argon using a liquid argon detector at the Oak Ridge
National Laboratory Spallation Neutron Source. Two independent analyses prefer
\cevns over the background-only null hypothesis with greater than
significance. The measured cross section, averaged over the incident neutrino
flux, is (2.2 0.7) 10 cm -- consistent with the
standard model prediction. The neutron-number dependence of this result,
together with that from our previous measurement on CsI, confirms the existence
of the \cevns process and provides improved constraints on non-standard
neutrino interactions.Comment: 8 pages, 5 figures with 2 pages, 6 figures supplementary material V3:
fixes to figs 3,4 V4: fix typo in table 1, V5: replaced missing appendix, V6:
fix Eq 1, new fig 3, V7 final version, updated with final revision
Statistical Derivation of Basic Equations of Diffusional Kinetics in Alloys with Application to the Description of Diffusion of Carbon in Austenite
Basic equations of diffusional kinetics in alloys are statistically derived
using the master equation approach. To describe diffusional transformations in
substitution alloys, we derive the "quasi-equilibrium" kinetic equation which
generalizes its earlier versions by taking into account possible "interaction
renormalization" effects. For the interstitial alloys Me-X, we derive the
explicit expression for the diffusivity D of an interstitial atom X which
notably differs from those used in previous phenomenological treatments. This
microscopic expression for D is applied to describe the diffusion of carbon in
austenite basing on some simple models of carbon-carbon interaction. The
results obtained enable us to make certain conclusions about the real form of
these interactions, and about the scale of the "transition state entropy" for
diffusion of carbon in austenite.Comment: 26 pages, 5 postscript figures, LaTe
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