353 research outputs found
Hidden attractors in fundamental problems and engineering models
Recently a concept of self-excited and hidden attractors was suggested: an
attractor is called a self-excited attractor if its basin of attraction
overlaps with neighborhood of an equilibrium, otherwise it is called a hidden
attractor. For example, hidden attractors are attractors in systems with no
equilibria or with only one stable equilibrium (a special case of
multistability and coexistence of attractors). While coexisting self-excited
attractors can be found using the standard computational procedure, there is no
standard way of predicting the existence or coexistence of hidden attractors in
a system. In this plenary survey lecture the concept of self-excited and hidden
attractors is discussed, and various corresponding examples of self-excited and
hidden attractors are considered
Change in stability of solid solution at radiation influence
Stability of solid solution at radiation influence has been investigated. Expressions for diffusion streams of binary alloy components, which specify the existence of temperature interval in which the phenomenon of ascending diffusion of elements is observed, were received. Vacancy characters of diffusion, configuration entropy, and potential energy of atomic bonds were considered at derivation. The ascending diffusion testifies to stability infringement of homogeneous solid solution - stratification. Influence of radiation is connected with increase in concentration of vacancies which changes the energy of atomic bonds and, simultaneously, accelerates diffusion processes. The condition of alloy stability with regard to stratification at radiating influence was obtaine
MORTALITY IN EXPERIMENTAL AND NATURAL INFECTION CAUSED BY HIGHLY PATHOGENIC INFLUENZA VIRUS H5N1
In this paper the data for mortality from experimental infections and natural contamination in different species of poultry is presented. Mortality of natural contamination was identified during the epizootic of influenza in the Novosibirsk area in July 2005. We infected domestic geese, ducks and two breeds of chickens with highly pathogenic influenza virus A/goose/Krasnoozerskoye/627/05 (H5N1) for the experiments constructed
Обработка и анализ данных натурного эксперимента по определению характеристик движения круглого парашюта по траектории в виде спирали на больших высотах
The article is addressed to the analysis of the trajectory parameters and videos obtained during the flight experiment at the launch of meteo-rocket MMP-06 with the purpose to determine major parameters of motion of a round parachute at subsonic speeds in the range of altitudes from 0 to 40 km. The data analysis showed that the trajectory of the parachute represents spiral "stretched" by the wind in the horizontal direction and disturbed by random factors of a non-stationary flow around the parachute. The main parameters of the trajectory are obtained according to the experimental data. Only qualitative analysis of spiral motion paths for round parachutes may be found in the publications on parachute subjects. This article presents the quantitative characteristics of this process.Статья посвящена обработке и анализу траекторных параметров и видеозаписи, полученных во время лётного эксперимента при пуске метеоракеты ММР-06, с целью определения основных параметров движения круглого парашюта на дозвуковой скорости в диапазоне высот от 0 км до 40 км. Анализ данных показал, что траектория движения ПС представляет собою спираль, «растянутую» ветром в горизонтальном направлении и возмущённую случайными факторами нестационарного обтекания парашюта. По экспериментальным данным получены зависимости основных параметров движения ПС. В литературе по парашютной тематике встречается только качественный анализ спиралевидных траекторий движения круглых парашютов. В данной статье получены количественные характеристики этого процесса
GEOLOGICAL AND GEOPHYSICAL TRANSECT OF THE MIDDLE TIEN SHAN ACROSS THE NARYN AND ATBASHI DEPRESSIONS
The article presents the results of integrated geological and geophysical research works dealt with detailed magnetotelluric (MT) sounding and the study of the morphology and spatial position of the sedimentary cover and basement structures along the key transect of the Middle Tien Shan crossing the Naryn and Atbashi depressions. The data on the distribution of deep electrical conductivity of the crust and upper mantle were compared with the seismic profiling data. The compilation of the results of structural-geological and geophysical studies provided the opportunity to draw 2D upper-crust geological structure, consistent with the structure of electrical conductivity of the crust to depths of about 10 km. The detailed geological cross-sections and the structural and geological data allow us to characterize the deformations of the Cenozoic sedimentary complex and Paleozoic basement surface associated with the alpine activation of the key segment of the Tien Shan. It is shown that the Cenozoic structural parageneses emerged during a relatively short-term phase of deformation and orogeny under conditions of horizontal compression and transpression, which did not manifest themselves during sagging that occurred previously
Capabilities of the GAMMA-400 gamma-ray telescope to detect gamma-ray bursts from lateral directions
The currently developing space-based gamma-ray telescope GAMMA-400 will
measure the gamma-ray and electrons + positrons fluxes using the main top-down
aperture in the energy range from ~20 MeV to several TeV in the highly elliptic
orbit (without shadowing the telescope by the Earth and outside the radiation
belts) continuously for a long time. The instrument will provide fundamentally
new data on discrete gamma-ray sources, gamma-ray bursts (GRBs), sources and
propagation of Galactic cosmic rays and signatures of dark matter due to its
unique angular and energy resolutions in the wide energy range. The gamma-ray
telescope consists of the anticoincidence system (AC), the converter-tracker
(C), the time-of-flight system (S1 and S2), the position-sensitive and
electromagnetic calorimeters (CC1 and CC2), the top and bottom scintillation
detectors of the calorimeter (S3 and S4) and lateral detectors of the
calorimeter (LD). In this paper, the capabilities of the GAMMA-400 gamma-ray
telescope to measure fluxes of GRBs from lateral directions of CC2 are analyzed
using Monte-Carlo simulations. The analysis is based on second-level trigger
construction using signals from S3, CC2, S4 and LD detectors. For checking the
numerical algorithm the data from space-based GBM and LAT instruments of the
Fermi experiment are used, namely, three long bursts: GRB 080916C, GRB 090902B,
GRB 090926A and one short burst GRB 090510A. The obtained results allow us to
conclude that from lateral directions the GAMMA-400 space-based gamma-ray
telescope will reliably measure the spectra of bright GRBs in the energy range
from ~10 to ~100 MeV with the effective area of about 0.13 m2 (for each of the
four sides of CC2) and total field of view of about 6 sr.Comment: 19 pages, 18 figures, the paper will be submitted to Advances in
Space Researc
Electrically-driven phase transition in magnetite nanostructures
Magnetite (FeO), an archetypal transition metal oxide, has been
used for thousands of years, from lodestones in primitive compasses[1] to a
candidate material for magnetoelectronic devices.[2] In 1939 Verwey[3] found
that bulk magnetite undergoes a transition at T 120 K from a
high temperature "bad metal" conducting phase to a low-temperature insulating
phase. He suggested[4] that high temperature conduction is via the fluctuating
and correlated valences of the octahedral iron atoms, and that the transition
is the onset of charge ordering upon cooling. The Verwey transition mechanism
and the question of charge ordering remain highly controversial.[5-11] Here we
show that magnetite nanocrystals and single-crystal thin films exhibit an
electrically driven phase transition below the Verwey temperature. The
signature of this transition is the onset of sharp conductance switching in
high electric fields, hysteretic in voltage. We demonstrate that this
transition is not due to local heating, but instead is due to the breakdown of
the correlated insulating state when driven out of equilibrium by electrical
bias. We anticipate that further studies of this newly observed transition and
its low-temperature conducting phase will shed light on how charge ordering and
vibrational degrees of freedom determine the ground state of this important
compound.Comment: 17 pages, 4 figure
Зоны концентрированной деформации (структуры цветка): натурные наблюдения и данные моделирования
Our study was focused on narrow linear zones that penetrate to different depths the crust and have complex infrastructure. Rocks in such zones are more intensively tectonically altered in comparison with the background. ‘Flower structures’ and ‘zones of concentrated deformation’ (ZCD) are the terms to describe these zones. The field study results combined with the data of tectonophysical and computational modeling data and supplemented by the literature analysis gave grounds for the following conclusions. In the experiments, as well as in nature, ZCDs show similar and, in some cases, identical morphological and infrastructural features and have similar stages of their evolution. A ZCD is mainly a reflection of the transpression setting. Its formation is accompanied by 3D plastic shear flow of matter and dilatancy of the deformed volume. A ZCD may be associated with the development of the ‘basement – cover’ system. It may also occur due to the intra-cover tectogenesis that does not influence the basement. Locations of ZCDs are spatially regular and predetermine the tectonic divisibility of the crust and lithosphere.В настоящее время большое внимание уделяется изучению узких линейных зон, которые, пронизывая земную кору на разную глубину, характеризуются сложной инфраструктурой и интенсивной в сравнении с фоновой тектонической переработкой горных масс. Такие структуры получили название «структуры цветка» или «зоны концентрированной деформации». Изучение натурных объектов вкупе с данными тектонофизического и расчетного моделирования, дополненное анализом литературного материала, позволило сделать следующие выводы: ЗКД в эксперименте и в природных объектах обнаруживают сходство, иногда тождество, по морфологии, инфраструктуре, этапности эволюции; ЗКД отражают преимущественно обстановки транспрессии, и их формирование сопровождается 3D пластическим сдвиговым течением вещества и дилатансией деформируемого объема; возникновение ЗКД может быть связано с развитием системы «фундамент – чехол», но может определяться и внутричехольным тектогенезом, не затрагивающим фундамент; ЗКД обладают пространственно-регулярным расположением и определяют тектоническую делимость земной коры и литосферы.
Dark Matter Search Perspectives with GAMMA-400
GAMMA-400 is a future high-energy gamma-ray telescope, designed to measure
the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be
produced by annihilation or decay of dark matter particles, and to survey the
celestial sphere in order to study point and extended sources of gamma-rays,
measure energy spectra of Galactic and extragalactic diffuse gamma-ray
emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400
covers the energy range from 100 MeV to ~3000 GeV. Its angular resolution is
~0.01 deg(Eg > 100 GeV), and the energy resolution ~1% (Eg > 10 GeV). GAMMA-400
is planned to be launched on the Russian space platform Navigator in 2019. The
GAMMA-400 perspectives in the search for dark matter in various scenarios are
presented in this paperComment: 4 pages, 4 figures, submitted to the Proceedings of the International
Cosmic-Ray Conference 2013, Brazil, Rio de Janeir
- …