471 research outputs found
Технические средства реабилитации людей с ограничением жизнедеятельности: методическая разработка по английскому языку для студентов-дефектологов
The article is devoted to the methodic working studies in English for special needs students. The aim of studies is development skills in reading special texts containing vocabulary for communication in English with socially handicapped people.В статье представлен конспект занятия по английскому языку для студентов-дефектологов. Цель занятия — совершенствование навыков чтения специальных текстов, содержащих лексико-речевые конструкции, необходимые для осуществления коммуникации на английском языке в сфере образования лиц с ограниченными возможностями здоровья
Biodiversity of Small Mammals and Paleoenvironment of Transbaikalia and North Mongolia in the Late Pliocene
This paper reports the results of analysis on small mammal faunas dwelling during the Late Pliocene the Transbaikal and Northern Mongolia regions. They were found to share many common species, even though some differences linked with local and regional specifics of the environment are the case. High diversity of small mammal taxa, species richness and their prominent quantity specify the localities of Udunga, Beregovaya and Tologoi in Transbaikal region and in Shamar of Northern Mongolia. The compositions of all faunas point to the existence of the savanna-like landscapes and warm semiarid climate in that period
Star formation in the S233 region
The main objective of this paper is to study the possibility of triggered
star formation on the border of the HII region S233, which is formed by a
B-star. Using high-resolution spectra we determine the spectral class of the
ionizing star as B0.5 V and the radial velocity of the star to be -17.5(1.4)
km/s. This value is consistent with the velocity of gas in a wide field across
the S233 region, suggesting that the ionizing star was formed from a parent
cloud belonging to the S233 region. By studying spatial-kinematic structure of
the molecular cloud in the S233 region, we detected an isolated clump of gas
producing CO emission red-shifted relative to the parent cloud. In the UKIDSS
and WISE images, the clump of gas coincides with the infrared source containing
a compact object and bright-rimmed structure. The bright-rimmed structure is
perpendicular to the direction of the ionizing star. The compact source
coincides in position with IRAS source 05351+3549. All these features indicate
a possibility of triggering formation of a next-generation star in the S233
region. Within the framework of a theoretical one-dimensional model we conclude
that the "collect-and-collapse" process is not likely to take place in the S233
region. The presence of the bright-rimmed structure and the compact infrared
source suggest that the "collapse of the pre-existing clump" process is taking
place.Comment: 12 pages, 10 figure
Controlling high-frequency collective electron dynamics via single-particle complexity
We demonstrate, through experiment and theory, enhanced high-frequency
current oscillations due to magnetically-induced conduction resonances in
superlattices. Strong increase in the ac power originates from complex
single-electron dynamics, characterized by abrupt resonant transitions between
unbound and localized trajectories, which trigger and shape propagating charge
domains. Our data demonstrate that external fields can tune the collective
behavior of quantum particles by imprinting configurable patterns in the
single-particle classical phase space.Comment: 5 pages, 4 figure
Metal-poor stars observed with the automated planet finder telescope. I. Discovery of five carbon-enhanced metal-poor stars from LAMOST
We report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in
the metallicity range of [Fe/H] . These stars were selected from
the LAMOST DR3 low-resolution (R 2,000) spectroscopic database as
metal-poor candidates and followed-up with high-resolution spectroscopy (R110,000) with the LICK/APF. Stellar parameters and individual abundances
for 25 chemical elements (from Li to Eu) are presented for the first time.
These stars exhibit chemical abundance patterns that are similar to those
reported in other literature studies of very and extremely metal-poor stars.
One of our targets, J21140616, shows high enhancement in carbon
([C/Fe]=1.37), nitrogen ([N/Fe]= 1.88), barium ([Ba/Fe]=1.00), and europium
([Eu/Fe]=0.84). Such chemical abundance pattern suggests that J21140616 can
be classified as CEMP-r/s star. In addition, the star J1054+0528 can be
classified as a CEMP-rI star, with [Eu/Fe]=0.44 and [Ba/Fe]=0.52. The other
stars in our sample show no enhancements in neutron-capture elements and can be
classified as CEMP-no stars. We also performed a kinematic and dynamical
analysis of the sample stars based on Gaia DR2 data. The kinematic parameters,
orbits, and binding energy of these stars, show that J21140616 is member of
the outer halo population, while the remaining stars belong to the inner halo
population but with an accreted origin. Collectively, these results add
important constraints on the origin and evolution of CEMP stars as well as on
their possible formation scenarios
The lichen genera Thelidium and Verrucaria in the Leningrad Region (Russia)
Lichens from the genera Thelidium and Verrucaria in the Leningrad Region (including Saint-Petersburg) are revised. Altogether five species of Thelidium and 31 of Verrucaria are confirmed for this region. Four species (Thelidium minimum, T. olivaceum, Verrucaria maculiformis and V. trabalis) are new to the Leningrad Region, and 17 species (Thelidium aphanes, T. fontigenum, Verrucaria christiansenii, V. elevata, V. epilithea, V. helsingiensis, V. illinoisensis, V. inaspecta, V. invenusta, V. ligni- cola, V. pilosoides, V. polystictoides, V. pseudovirescens, V. rejecta, V. tectorum, V. tornensis and V. transfugiens) are new to Russia. Dubious records for the Leningrad Region include Verrucaria acrotella, V. floerkeana, V. fusca, V. nigrescens, V. obnigrescens, V. umbrinula and V. viridula.
Orbital and physical parameters of the spectroscopic binary HD37737
We report the physical and orbital parameters of the visible component of the spectroscopic binary HD37737 (m V = 8.03). The observations were performed with the 1.2-m telescope of the Kourovka Astronomical Observatory of the Ural Federal University in 2012 and the 6-m BTA telescope of the SAO RAS in 2007 and 2009. Radial velocities were measured separately from each spectral line of the list by the cross-correlation method with a synthetic spectrum. The latter was calculated using the grids of non-LTE model atmospheres with solar chemical compositions. A significant difference in the epochs of observations (2005-2012) allowed to refine the orbital period of the star (7· d84705) and the orbital elements of the binary system. We obtained an estimate of the mass function f(m) = 0.23 ± 0.02M ⊙. The best agreement between the synthetic and observed spectra is achieved at T eff = 30 000 K and log g = 3.50 according to the observations on both instruments. The obtained parameters correspond to a star of spectral type O9.5 III, with mass estimated at 26 ± 2M ⊙. The minimum mass estimate of the secondary component of the binary is 6.2 ± 0.5M ⊙. We have discovered a fact that the velocities, obtained from different spectral lines, differ, which is typical for giant stars. Engaging additional spectra, obtained in 2005 with the 2.1-m KPNO telescope, we investigated the effect of this fact on the estimate of the speed of the system's center of mass. The difference in the velocities of various lines is approximately the same in the spectra, obtained at all the three instruments. The obtained ratios suggest that the deeper layers of the atmosphere of the star are moving with a greater velocity than the outer layers. Depending on the line, the estimate of the heliocentric velocity of the binary's center of mass varies in the range from -11 to 1 km/s. © 2013 Pleiades Publishing, Ltd
Prediction of physical-chemical and fire hazard characteristics by carbon chain rules. 2. Carboxylic acids
Investigation of the dependence of physico-chemical and fire hazard properties from the chemical structure of carboxylic acids is carried out. Forecasting of the boiling temperature, the flash point, the temperature and the concentration flammability limits, the heats of combustion and vaporization is performed by the carbon chain rules (CCR). The following empirical equations for the calculation of physico-chemical and fire hazard indices from the conventional carbon chain and from the number of carbon atoms are proposed for the convenience of practical application of the CCR. A comparative analysis of the proposed methods for the flash point calculating and the already known methods of GOST 12.1.044-89, Mendeleev and ACD/Lab 2014 is carried out. It is shown, basically, that the new methods give more accurate calculation results than the comparison design procedures. © Siberian Federal University. All rights reserve
Terahertz Bloch oscillator with a modulated bias
Electrons performing Bloch oscillations in an energy band of a dc-biased
superlattice in the presence of weak dissipation can potentially generate THz
fields at room temperature. The realization of such Bloch oscillator is a
long-standing problem due to the instability of a homogeneous electric field in
conditions of negative differential conductivity. We establish the theoretical
feasibility of stable THz gain in a long superlattice device in which the bias
is quasistatically modulated by microwave fields. The modulation waveforms must
have at least two harmonics in their spectra.Comment: 5 page
Systematic NLTE study of the -2.6 < [Fe/H] < 0.2 F and G dwarfs in the solar neighbourhood. I. Stellar atmosphere parameters
We present atmospheric parameters for 51 nearby FG dwarfs uniformly
distributed over the -2.60 < [Fe/H] < +0.20 metallicity range that is suitable
for the Galactic chemical evolution research. Lines of iron, Fe I and Fe II,
were used to derive a homogeneous set of effective temperatures, surface
gravities, iron abundances, and microturbulence velocities. We used
high-resolution (R>60000) Shane/Hamilton and CFHT/ESPaDOnS observed spectra and
non-local thermodynamic equilibrium (NLTE) line formation for Fe I and Fe II in
the classical 1D model atmospheres. The spectroscopic method was tested with
the 20 benchmark stars, for which there are multiple measurements of the
infrared flux method (IRFM) Teff and their Hipparcos parallax error is < 10%.
We found NLTE abundances from lines of Fe I and Fe II to be consistent within
0.06 dex for every benchmark star, when applying a scaling factor of S_H = 0.5
to the Drawinian rates of inelastic Fe+H collisions. The obtained atmospheric
parameters were checked for each program star by comparing its position in the
log g-Teff plane with the theoretical evolutionary track in the Yi et al.
(2004) grid. Our final effective temperatures lie in between the T_IRFM scales
of Alonso et al. (1996) and Casagrande et al. (2011), with a mean difference of
+46 K and -51 K, respectively. NLTE leads to higher surface gravity compared
with that for LTE. The shift in log g is smaller than 0.1 dex for stars with
either [Fe/H] > -0.75, or Teff 4.20. NLTE analysis is
crucial for the VMP turn-off and subgiant stars, for which the shift in log g
between NLTE and LTE can be up to 0.5 dex. The obtained atmospheric parameters
will be used in the forthcoming papers to determine NLTE abundances of
important astrophysical elements from lithium to europium and to improve
observational constraints on the chemo-dynamical models of the Galaxy
evolution.Comment: 18 pages, 14 figures, accepted for publication in Ap
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