425 research outputs found
Preliminary results of investigation of solid interplanetary matter in the vicinity of the moon
Density of matter near moon found to be greater than that of interplanetary spac
Synchrotron Self-Compton Model for Rapid Nonthermal Flares in Blazars with Frequency-Dependent Time Lags
We model rapid variability of multifrequency emission from blazars occurring
across the electromagnetic spectrum (from radio to gamma-rays). Lower energy
emission is produced by the synchrotron mechanism, whereas higher energy
emission is due to inverse Compton scattering of the synchrotron emission. We
take into account energy stratification established by particle acceleration at
shock fronts and energy losses due to synchrotron emission. We also consider
the effect of light travel delays for the synchrotron emission that supplies
the seed photons for inverse Compton scattering. The production of a flare is
caused by the collision between a relativistic shock wave and a stationary
feature in the jet (e.g., a Mach disk). The collision leads to the formation of
forward and reverse shocks, which confine two contiguous emission regions
resulting in complex profiles of simulated flares. Simulations of
multifrequency flares indicate that relative delays between the inverse Compton
flares and their synchrotron counterparts are dominated by energy
stratification and geometry of the emitting regions, resulting in both negative
and positive time delays depending on the frequency of observation. Light
travel effects of the seed photons may lead to a noticeable delay of the
inverse Compton emission with respect to synchrotron variability if the line of
sight is almost perfectly aligned with the jet. We apply the model to a flare
in 3C 273 and derive the properties of shocked plasma responsible for the
flare. We show that the pronounced negative time delay between the X-ray and IR
light curves (X-rays peak after the maximum in the synchrotron emission) can be
accounted for if both forward and reverse shocks are considered.Comment: 48 pages, 18 figures, accepted for publication in The Astrophysical
Journa
ОСНОВНЫЕ ТИПЫ ИННОВАЦИОННЫХ МАЛЫХ И СРЕДНИХ ПРЕДПРИЯТИЙ
Conversion of Eastern Europe countries and RF to market economics causes many organizational, legal and infrastructural problems to rise. By the degree of «innovativeness», minor and medium enterprises are classified to three categories: «leader», «successor» and «outsider». Minor enterprises to whom different support may be extended by regional powers are grouped to 4 types.Переход стран Восточной Европы и Российской Федерации к рыночному типу экономики порождает много организационно-правовых и инфраструктурных проблем. По степени инновационности МСП относятся к категориям «лидер», «последователь» и «аутсайдер». Малые инновационные предприятия, которым может быть предоставлена различная поддержка региональных органов власти, разделены на 4 типа
НАПРАВЛЕНИЯ СТИМУЛИРОВАНИЯ И РАЗВИТИЯ МАЛОГО ПРЕДПРИНИМАТЕЛЬСТВА В РОССИЙСКОЙ ФЕДЕРАЦИИ
Small-scale entrepreneurship is not given sufficient attention on the part of the Russian Federation Government. Ways and instruments of maximum effective stimulation of this important business field are discussed. Lack of well-thought governmental policy is main problem in this respect.В Российской Федерации развитию малого предпринимательства со стороны государства уделяется недостаточно внимания. Показаны направления и инструменты максимально эффективного стимулирования этой важной сферы бизнеса. Главной проблемой здесь является отсутствие четко продуманной государственной политики
МАЛЫЕ ИННОВАЦИОННЫЕ ПРЕДПРИЯТИЯ И МЕТОДЫ ИХ ФИНАНСИРОВАНИЯ В РОССИИ
Minor enterprises do not have resources sufficient for investment. Present experience of venture financing and attraction of funds from finance markets is poor in Russia. Main minor entrepreneurship financing sources are state allocations in the form of subsidies, subventionsand donations. This support promotes economics diversification and increases jobs. The state becomes client of innovations and provides for business environment favorable for minor entrepreneurship and for subsequent diffusion of innovations. One of most efficient innovationactivity stimulation methods (applied to minor enterprises as well) is provision for tax privileges, favorable state bank credits and preferences to innovation activity supporting commercial banks.Малые предприятия достаточными средствами для инвестиций не обладают. Опыт венчурного финансирования малого предпринимательства и привлечение для этой цели средств на финансовом рынке в России пока мал. Основной источник финансирования – государственные ассигнования в форме субсидий, субвенций и дотаций. Эта поддержка способствует также диверсификации экономики и повышению занятости. Государство выполняет роль заказчика инноваций и обеспечивает формирование бизнес-среды для возникновения малых предприятий и для последующей диффузии инноваций. Одним из наиболее действенных методов стимулирования инновационной деятельности, в том числе малых предприятий, является предоставление налоговых льгот и льготных кредитов государственных банков или преференций коммерческим банкам, кредитующим инновационную деятельность
Comptonization of Infrared Radiation from Hot Dust by Relativistic Jets in Quasars
We demonstrate the importance of near-infrared radiation from hot dust for
Compton cooling of electrons/positrons in quasar jets. In our model, we assume
that the non-thermal radiation spectra observed in OVV quasars are produced by
relativistic electrons/positrons accelerated in thin shells which propagate
down the jet with relativistic speeds. We show that the Comptonization of the
near-IR flux is likely to dominate the radiative output of OVV quasars in the
energy range from tens of keV up to hundreds of MeV, where it exceeds that
produced by Comptonization of the UV radiation reprocessed and rescattered in
the Broad Emission Line region. The main reason for this lies in the fact that
the jet encounters the ambient IR radiation over a relatively large distance as
compared to the distance where the energy density of the broad emission line
light peaks. In the soft - to mid energy X-ray band, the spectral component
resulting from Comptonization of the near-IR radiation joins smoothly with the
synchrotron-self-Compton component, which may be responsible for the soft X-ray
flux. At the highest observed gamma-ray energies, in the GeV range,
Comptonization of broad emission lines dominates over other components.Comment: 23 pages, including 5 Postscript figures and 3 tables, uses aastex.
Astrophysical Journal, accepted for publication in the December 20, 2000
issu
Contemporary long-term trends in water discharge, suspended sediment load, and erosion intensity in river basins of the North Caucasus region, SW Russia
For the first time, contemporary trends in water discharge, suspended sediment load, and the intensity of overall erosion in the river basins of the North Caucasus region, as one of Russia’s most agriculturally developed geographic areas, were identified. The study was carried out using monitoring data of the Federal Service for Hydrometeorology and Environmental Monitoring of the country for 21 rivers by comparing two periods: 1963-1980 and 2008-201
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