1,237 research outputs found
Biological resources of the Hyssopus l on the south of European Russia and prospects of its introduction
The south of European Russia (geographically - the southern part of the Central Russian Upland) has large biological and plant genetic resources. There is a concept considering the region as the second anthropogenic microgen center of formation of economically valuable plants. In the south of the Central Russian Upland, the genus Hyssopus L. is represented by two species: Hyssopus cretaceus Dubjan. and Hyssopus officinalis L. Accomplished the study of biological resources of species of the genus Hyssopus L. in vivo and in vitr
Curing of epoxy resin DER-331by Hexakis (4-acetamidophenoxy) cyclotriphosphazene and properties of the prepared composition
The method of optical wedge revealed that the optimum temperature for compatibility of hexakis(4-acetamidophenoxy)cyclotriphosphazene (ACP) and DER-331 epoxy resin is in the range of 220–260◦C. The interdiffusion time of components at these temperatures is about 30 min. The TGA and differential scanning calorimetry (DSC) methods revealed the curing temperature of 280◦C for thiscomposition. IRspectroscopyconfirmedthatthereactionbetweentheresinandACPiscompleted within 10 mi
Controlling circular polarization of light emitted by quantum dots using chiral photonic crystal slab
We study the polarization properties of light emitted by quantum dots that
are embedded in chiral photonic crystal structures made of achiral planar GaAs
waveguides. A modification of the electromagnetic mode structure due to the
chiral grating fabricated by partial etching of the wave\-guide layer has been
shown to result in a high circular polarization degree of the quantum
dot emission in the absence of external magnetic field. The physical nature of
the phenomenon can be understood in terms of the reciprocity principle taking
into account the structural symmetry. At the resonance wavelength, the
magnitude of is predicted to exceed 98%. The experimentally achieved
value of % is smaller, which is due to the contribution of
unpolarized light scattered by grating defects, thus breaking its periodicity.
The achieved polarization degree estimated removing the unpolarized nonresonant
background from the emission spectra can be estimated to be as high as 96%,
close to the theoretical prediction
Laser acceleration of ion beams
We consider methods of charged particle acceleration by means of
high-intensity lasers. As an application we discuss a laser booster for heavy
ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a
cascade of crossed laser beams would be necessary to provide additional
acceleration to gold ions of the order of GeV/nucleon.Comment: 4 pages, 4 figures, Talk at the Helmholtz International Summer School
"Dense Matter in heavy Ion Collisions and Astrophysics", August 21 -
September 1, 2006, JINR Dubna, Russia; v2, misprints correcte
Mobilization of genetic resources of Hyssopus Officinalis L. for selection for seed productivity and essential oil content
We studied 52 varieties and breeding samples from the collection of medicinal hyssop in the Botanical Garden of Belgorod State University (2017-2020). Of these, 16 varieties of domestic selection included in the State Register of Breeding Achievements approved for use in the Russian Federation, as well as 33 breeding samples obtained by selection from wild cenopopulations of the Volokonovsky district of the Belgorod region and 3 breeding samples obtained by selection from local selection varieties ‘Volokonovsky’ (2 samples) and ‘Lazar’ (1 sample
BBGKY kinetic approach for an e-e+gamma plasma created from the vacuum in a strong laser-generated electric field: The one-photon annihilation channel
In the present work a closed system of kinetic equations is obtained from the
truncation of the BBGKY hierarchy for the description of the vacuum creation of
an electron - positron plasma and secondary photons due to a strong laser
field. This truncation is performed in the Markovian approximation for the
one-photon annihilation channel which is accessible due to the presence of the
strong external field. Estimates of the photon production rate are obtained for
different domains of laser field parameters (frequency nu and field strength
E). A huge quantity of optical photons of the quasiclassical laser field is
necessary to satisfy the conservation laws of energy and momentum of the
constituents (e-, e+, gamma) in this channel. Since the number of these optical
photons corresponds to the order of perturbation theory, a vanishingly small
photon production rate results for the optical region and strongly subcritical
fields E << E_c. In the gamma-ray region nu <~ m the required number of laser
photons is small and the production rate of photons from the one-photon
annihilation process becomes accessible to observations for subcritical fields
E <~ E_c. In the infrared region the photon distribution has a 1/k spectrum
typical for flicker noise.Comment: 14 pages, 1 figure, one reference with referring text added and one
citation correcte
Additive scaling law for structural organization of chromatin in chicken erythrocyte nuclei
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