Перегляд за Автор "Костенко, В.В."

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On the periodic change of the luminosity of the cosmic sources with an active medium
(2020) Kostenko, V.V.; Kuklin, V.M.; Poklonskiy, E.V.; Костенко, В.В.; Куклін, В.М.; Поклонський, Є.В.
The presence of an internal layer with an active medium in a hot radiation source is considered, which can be described by a quantum two-level system located near equilibrium. The population of the upper and lower levels is approximately equal. It is shown that during convection from deeper hot layers, which supports the inversion of the populations of the active system, generation of induced radiation pulses is possible, the intensity of which is comparable to or greater than the intensity of the background spontaneous radiation of the source. With a sufficient thickness of the surface layers due to the effects of radiation scattering in them, the emission spectrum of a completely black body may well form there. Pulse generation near a previously detected new threshold of induced radiation can lead to a periodic change in the radiation intensity of the source as a whole. This threshold is determined by the equality of the squared population inversion to the total number of states. The generation of pulses of induced radiation is considered both in Einstein's representation, on the basis of balanced equations, and using a semiclassical description for small values of population inversion and for low levels of electric field intensity, when the Rabi frequency is less than the line width. The description of the induced radiation process is reduced to a one-parameter system of equations. Periodic solutions are represented by closed trajectories on the phase plane (relative density of quanta, relative density of population inversion). A similar layer with an active medium, which can be described by a quantum two-level system located near equilibrium, can exist in stars and is most likely localized in the photosphere. If there is significant convection in the star’s atmosphere, conditions can be realized for generating pulses of induced radiation. It turns out that one can see the similarity of the obtained solutions with known observations of changes in the luminosity of Cepheid stars (Cepheus delta and the North Star).
Изменения количественных признаков Drosophila melanogaster при действии донора метильных групп – бетаина. 1. Анализ компонентов приспособленности и экспрессивности признака radius incompletus
(Харківський національний університет імені В.Н.Каразіна, 2010) Волкова, Н.Е.; Филипоненко, Н.С.; Костенко, В.В.; Исипенко, Л.В.; Евстафьев, Д.С.; Навроцкая, В.В.; Воробьева, Л.И.
Проведено исследование действия метил-обогащенной диеты на проявление количественных признаков Drosophila melanogaster. Обнаружена обратно пропорциональная полиномиальная зависимость между концентрацией донора метильных групп бетаина в питательной среде и показателями плодовитости и жизнеспособности. Действие минимальной концентрации (1,3•10-5%) приводит к повышению жизнеспособности, плодовитости и к снижению гибели во время метаморфоза. Концентрация бетаина 5% в среде обусловливает снижение плодовитости и жизнеспособности линий, повышение уровня эмбриональной смертности, вызывает снижение экспрессивности мутантного признака radius incompletus (прерванная радиальная жилка крыла) у самцов. Жизнеспособность потомства (F1) особей, содержавшихся на среде с бетаином (1,3•10-1% и 5%) снижена по сравнению с контрольной группой. Концентрация бетаина 10% в среде является летальной для данного вида.