Immanuel Kant State University of Russia
Immanuel Kant State University of Russia
Zakharenkova I.E.,University of Warmia and Mazury |
Krankowski A.,University of Warmia and Mazury |
Krypiak-Gregorczyk A.,University of Warmia and Mazury |
Wielgosz P.,University of Warmia and Mazury |
Lagovsky A.F.,Immanuel Kant State University of Russia
Earth, Planets and Space | Year: 2012
The electron density profiles retrieved from the COSMIC radio occultation measurements were examined in order to estimate the possibility of its use as additional data source to study changes in electron density distribution occurred during ionospheric storms. The ionosphere behaviour during moderate geomagnetic storm which occurred on October 11, 2008 was analysed. The short-duration positive effect was revealed distinctly in GPS TEC and ionosonde measurements. For the European mid-latitude region it reached the factor of 2 or more relative to the undisturbed conditions. COSMIC data were analyzed and their validity was tested by comparison with ground-based measurements. It was shown the good agreement between independent measurements both in quiet and disturbed conditions. Analysis of COSMIC-derived electron density profiles revealed changes of the bottom-side and topside parts of the ionosphere. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS).
Yurov A.V.,Immanuel Kant State University of Russia |
Yurov V.A.,University of Missouri |
Chervon S.V.,Ulyanovsk State Pedagogical University |
Sami M.,Jamia Millia Islamia University
Theoretical and Mathematical Physics | Year: 2011
We study the class of integrable self-action potentials satisfying the conditions that (1) they spontaneously break the symmetry, (2) they describe the inflation phase with a graceful exit (i.e., with an exit that does not require fine tuning parameters), and (3) they feature several consecutive inflation phases. The first condition ensures that the inflation mechanism is qualitatively consistent with elementary particle physics, the second is a necessary ingredient of any inflation theory, and the third is necessary for a theory to be consistent with contemporary observational data, which support the accelerated expansion of the Universe. © 2011 MAIK/Nauka.
Bessarab P.F.,Saint Petersburg State University |
Radievsky A.V.,Immanuel Kant State University of Russia
Journal of Physics: Conference Series | Year: 2010
In the framework of the 2D and 3D time-dependent Ginzburg-Landau model we study superconductors with multicomponent order parameter (d-pairing). We argue that topological defects inside the sample do affect its thermodynamic properties such as hysteresis loop, susceptibility, etc. Along with earlier known topological defects such as Abrikosov vortices, domain walls (DWs) which separate different magnetic phases and even vortices inside the DW, we found an interesting combination of DWs and vortices. Namely we show that equivalent magnetic phases may be linked together with a vortex going through the other magnetic phase. This configuration may correspond to a stable state even in a zero external magnetic field. We also mention that this configuration is topologically similar to the 'wormholes' in the quantum gravity. © 2010 IOP Publishing Ltd.
Golubkov G.V.,RAS Semenov Institute of Chemical Physics |
Golubkov M.G.,RAS Semenov Institute of Chemical Physics |
Karpov I.V.,Immanuel Kant State University of Russia |
Devdariani A.Z.,Saint Petersburg State University
Russian Journal of Physical Chemistry B | Year: 2011
The emission ability of Rydberg atoms and molecules in the orbitally degenerate states is considered. The mechanisms of their formation in the F, E, and D upper atmosphere layers are analyzed. The characteristic lifetimes of these states in the microwave range are estimated. It is shown that radiation in this range can be accompanied by a cascade of transitions. The possibility of studying the influence of intense atmospheric microwave radiation on living organisms is discussed. © Pleiades Publishing, Ltd., 2011.
Tubelyte V.,Vytautas Magnus University |
Svazas S.,Institute of Ecology |
Sruoga A.,Vytautas Magnus University |
Sruoga A.,Institute of Ecology |
And 6 more authors.
Central European Journal of Biology | Year: 2011
The tufted duck (Aythya fuligula, Anatidae) is widespread in the Palaearctic across Northern Eurasia. Birds breeding in Northern and Eastern Europe are highly migratory, while populations from Western Europe are partially migratory or resident. The aim of this study is to explore genetic variation within and between ducks breeding in Latvia and migrants sampled in North West Russia and Belarus. The technique of random amplified polymorphic DNA was applied using five random primers (ol-1, ol-9-12). Genetic variability was measured for all tufted ducks investigated and for different sub-populations from various regions. Individual genetic structure and genetic variability was higher in ducks collected from Latvia. Gene diversity of amplified DNA bands in birds of Latvian origin was 24% with 80% polymorphism. Means of gene diversity and polymorphism for tufted ducks sampled in other countries varied from 12 to 14% and from 27 to 40%, respectively. A high number of unique bands characterized ducks breeding in Latvia. The oligonucleotide primers used in this study were suitable to analyze differences among tufted ducks of different origin. Possible explanations for the variation observed among the studied ducks are discussed. © 2011 Versita Warsaw and Springer-Verlag Wien.
Alekseenko E.,Immanuel Kant State University of Russia |
Aleshnikov S.,Immanuel Kant State University of Russia |
Markin N.,Cryptography Research |
Zaytsev A.,Claude Shannon Institute
Finite Fields and their Applications | Year: 2011
In this work we study the properties of maximal and minimal curves of genus 3 over finite fields with discriminant -19. We prove that any such curve can be given by an explicit equation of certain form (see Theorem 5.1). Using these equations we obtain a table of maximal and minimal curves over prime finite fields with discriminant -19 of cardinality up to 997. We also show that existence of a maximal curve implies that there is no minimal curve and vice versa. © 2011 Elsevier Inc. All rights reserved.
Dolnik C.,University of Kiel |
Peyrat J.,University of Kiel |
Volodina A.,Immanuel Kant State University of Russia |
Sokolov A.,Immanuel Kant State University of Russia
Polish Journal of Ecology | Year: 2011
Actively migrating dunes along the southern coast of the Baltic Sea have a very specific vegetation of annual pioneer plants, some of which are endemic to that area. This vegetation type was studied on the migrating dunes of the Łeba Bar (Poland) and the Curonian Spit (Russia and Lithuania) and is for the first time represented by 18 vegetation relevés according to the Braun-Blanquet approach. Typical plants on bare soil of active migrating dunes and sand fields in Baltic dunes are the endemics Corispermum intermedium (Chenopodiaceae), Cakile maritima subsp. baltica (Brassicaceae), and Linaria loeselii (Scrophulariaceae). A comparison of our field investigations with literature records revealed a gradual replacement of C. intermedium by the neophytic Siberian bugseed Corispermum pallasii (syn. C. leptopterum). C. intermedium uffered from severe habitat loss by dune afforestation, while the ruderal weed C. pallasii expanded its distribution range in the 20th century to various open gravel and sand fields in Europe, including dunes of the Baltic coast. New concepts of coastal conservation management, including aspects of coastal dynamics and nature conservation of endemic species, should be applied to conserve the remaining populations of C. intermedium.
Karpov I.V.,Russian Academy of Sciences |
Shagimuratov I.I.,Russian Academy of Sciences |
Yakimova G.A.,Russian Academy of Sciences |
Suslova O.P.,Immanuel Kant State University of Russia
Russian Journal of Physical Chemistry B | Year: 2011
The characteristics of total electron content (TEC) variations obtained using the data of middlelatitude stations for receiving GPS satellite signals were studied. An analysis showed that perturbations of diurnal TEC variations during a geomagnetic storm were determined by strengthening of harmonics with periods of 4-5 and 6-8 h. Perturbations in diurnal TEC variations were retained for several days after a geomagnetic storm. An analysis of the frequency and amplitude characteristics of perturbed variations showed that differences between variations at different latitudes could be explained by the propagation of Poincaré planetary waves in an atmospheric wave channel. The atmospheric channel was formed because of increased heating of pole regions during geomagnetic storms. A comparative analysis of observations made at different stations was used to estimate the width of the atmospheric channel and Poincaré wave frequencies and wave vector components. © Pleiades Publishing, Ltd., 2011.
Alekseeva L.M.,Moscow State University |
Kshvetskii S.P.,Immanuel Kant State University of Russia
Astrophysical Bulletin | Year: 2011
We study the behavior of the solar plasma over the photosphere in the zone of contact of oppositely directed magnetic fields. A special technique of numerical simulation is used, which allows passing to the class of generalized functions as soon as the solution loses smoothness. An initial-value problem is solved for the self-consistent nonlinear system of equations of collisional magneto-gas-dynamics under the assumption that the distribution of physical quantities is two-dimensional and the plasma has an initial temperature of 50 000 degrees. It is assumed that the magnetic field lines are straight, the physical quantities are constant along them, and the resulting fluid velocity is perpendicular to the magnetic field. It is shown that a pinch effect develops under such conditions, which gives rise to much more diverse effects in a natural ambient medium than in a laboratory plasma. The pinch effect produces narrow, variously directed jets of matter (including those going beyond the zone of contact of the fields), forms cross-shaped patterns in the distribution of the magnetic field, velocity and density, and gives rise to specific temperature nonuniformities. In the center of the contact zone, the plasma temperature increases (we terminate the computations when it doubles). The jet velocity can exceed 20 km/s. © 2011 Pleiades Publishing, Ltd.
Nikitina S.M.,Immanuel Kant State University of Russia |
Chibisova N.V.,RAS Shirshov Institute of Oceanology
Russian Journal of Developmental Biology | Year: 2011
Dynamics of changes in glucocorticoid (hydrocortisone and corticosterone) levels was studied in the ontogenesis of freshwater crawfish Astacus leptodactylus Esch. It was shown that steroid concentrations increase during the embryogenesis period. Decrease in the glucocorticoid levels during postembryonic development is most probably related to the stabilization of young fish growth and the attainment of hormone levels typical for adult individuals. The correlation of glucocorticoid levels with physiological-biochemical changes at different stages of ontogenesis indicates that these steroids play an essential role in the regulation of freshwater crawfish vital functions. © 2011 Pleiades Publishing, Ltd.