1,493 research outputs found
The efficiency coefficient of the rat heart and muscular system after physical training and hypokinesia
The efficiency of an isolated heart did not change after prolonged physical training of rats for an extreme load. The increase in oxygen consumption by the entire organism in 'uphill' running as compared to the resting level in the trained rats was 14% lower than in the control animals. Prolonged hypokinesia of the rats did not elicit a change in the efficiency of the isolated heart
New records of lichens from the Russian Far East. I. Fuscidea submollis and other arctic-alpine species
Summary. Fuscidea submollis Mas. Inoue is reported for the first time from the Russian Far East. Distinctive features of the taxon are discussed, and a comparison with known saxicolous Fuscidea V. Wirth & VÄzda species with amyloid medulla is made. Three arctic-alpine species: Sporastatia testudinea (Ach.) A. Massal., Buellia concinna Th. Fr., Amygdalaria panaeola (Ach.) Hertel et Brodo, and Aspilidea myrinii (Fr.) Hafellner are recorded for the first time in the South Far East from the Sikhote Alin Range (Primorye Territory). Calvitimela aglaea (Sommerf.) Hafellner is reported for the first time from Sikhote Alin Range and Primorye Territory. © 2019 Altai State University. All rights reserved.Japan Society for the Promotion of Science, JSPS: 19-54-50010Russian Foundation for Basic Research, RFBRThe reported study was funded by RFBR and JSPS according to the research project â 19-54-50010
Triaxial projected shell model approach
The projected shell model analysis is carried out using the triaxial
Nilsson+BCS basis. It is demonstrated that, for an accurate description of the
moments of inertia in the transitional region, it is necessary to take the
triaxiality into account and perform the three-dimensional angular-momentum
projection from the triaxial Nilsson+BCS intrinsic wavefunction.Comment: 9 pages, 2 figure
Nonlinearity-induced conformational instability and dynamics of biopolymers
We propose a simple phenomenological model for describing the conformational
dynamics of biopolymers via the nonlinearity-induced buckling and collapse
(i.e. coiling up) instabilities. Taking into account the coupling between the
internal and mechanical degrees of freedom of a semiflexible biopolymer chain,
we show that self-trapped internal excitations (such as amide-I vibrations in
proteins, base-pair vibrations in DNA, or polarons in proteins) may produce the
buckling and collapse instabilities of an initially straight chain. These
instabilities remain latent in a straight infinitely long chain, because the
bending of such a chain would require an infinite energy. However, they
manifest themselves as soon as we consider more realistic cases and take into
account a finite length of the chain. In this case the nonlinear localized
modes may act as drivers giving impetus to the conformational dynamics of
biopolymers. The buckling instability is responsible, in particular, for the
large-amplitude localized bending waves which accompany the nonlinear modes
propagating along the chain. In the case of the collapse instability, the chain
folds into a compact three-dimensional coil. The viscous damping of the aqueous
environment only slows down the folding of the chain, but does not stop it even
for a large damping. We find that these effects are only weakly affected by the
peculiarities of the interaction potentials, and thus they should be generic
for different models of semiflexible chains carrying nonlinear localized
excitations.Comment: 4 pages (RevTeX) with 5 figures (EPS
Triaxial deformation in 10Be
The triaxial deformation in Be is investigated using a microscopic
model. The states of two valence neutrons are classified
based on the molecular-orbit (MO) model, and the -orbit is introduced
about the axis connecting the two -clusters for the description of the
rotational bands. There appear two rotational bands comprised mainly of and , respectively, at low excitation energy, where the two
valence neutrons occupy or orbits. The
triaxiality and the -mixing are discussed in connection to the molecular
structure, particularly, to the spin-orbit splitting. The extent of the
triaxial deformation is evaluated in terms of the electro-magnetic transition
matrix elements (Davydov-Filippov model, Q-invariant model), and density
distribution in the intrinsic frame. The obtained values turned out to be
.Comment: 15 pages, latex, 3 figure
ON THE SPECIFIC FEATURES OF SILICON CARBIDE HETEROPOLYTYPE EPITAXY
Specific features of silicon carbide layer formation with the structure (polytype) different from the SiC-substrate structure (polytype) are considered. Simple theoretical foundations of the nonstoichiometric character, impurities, C- and Si-faces effect on the heteropolytype epitaxy (HPE) of silicon carbide are proposed. By means of Harrisonâs bond orbital model it is shown that the adsorption possibility for the C-face is much greater than for the Si-face. Within the scopes of the earlier proposed models (D-model and vacancy model) it is demonstrated that the presence of impurities changes characteristic lifetimes of the HPE process and the transition layer widths: impurities which enforce the interpolytype transition decrease corresponding life-time constants and the transition layer widths. For interpretation of the polytype stripes existence within the transition layer, the model of specific spinodal decomposition taking into account vacancy concentrations variations in both SiC sublattices is used
Quantum Electrodynamics and the Origins of the Exchange, Dipole-Dipole, and Dzyaloshinsky-Moriya Interactions in Itinerant Fermion Systems
It is shown how the exchange interaction, the dipole-dipole interaction, and
the Dzyaloshinsky-Moriya interaction between electronic spin-density
fluctuations emerge naturally from a field-theoretic framework that couples
electrons to the fluctuating electromagnetic potential. Semi-quantitative
estimates are given to determine when the dipole-dipole interaction, which is
often neglected, needs to be considered, and various applications are
discussed, with an emphasis on weak ferromagnets and on helimagnets.Comment: 12pp, 3 fig
Relativistic quantum mechanics of a Dirac oscillator
The Dirac oscillator is an exactly soluble model recently introduced in the
context of many particle models in relativistic quantum mechanics. The model
has been also considered as an interaction term for modelling quark confinement
in quantum chromodynamics. These considerations should be enough for
demonstrating that the Dirac oscillator can be an excellent example in
relativistic quantum mechanics. In this paper we offer a solution to the
problem and discuss some of its properties. We also discuss a physical picture
for the Dirac oscillator's non-standard interaction, showing how it arises on
describing the behaviour of a neutral particle carrying an anomalous magnetic
moment and moving inside an uniformly charged sphere.Comment: 19 pages, 1 figur
GIANT OPTICAL NONLINEARITY OF HETEROSTRUCTURES WITH InP SELF-ASSEMBLED QUANTUM DOTS
A nonlinear reection of the heterostructures with InP self-assembled quantumdots is studied by pump-probe technique. A saturation of pump-probe signal inthe spectral region of the absorption of quantum dots is found at extremely lowpump power density of about 1 W/cm2. This value together with estimation ofthe absorption coefficient leads to the conclusion that saturation of the nonlinearreection occurs when quantum dot absorbs only single quantum of the light. Thisis a real evidence of the giant optical nonlinearity of the quantum dots.24th International Conference on the Physics of Semiconductors : Jerusalem, Israel August 2-7, 199
- âŠ