The high-intensity and monochromatic radiation sources in the water window spectral range are desirable for many applications. One of the potential candidates of soft X-ray sources is polarization ...radiation produced by a charged particle passing through a thin foil. In the soft X-ray range near the absorption edges of a target material, the real part of dielectric permittivity can exceed unity, and the Tamm–Frank criterion is fulfilled. Thus, two types of radiation are produced: transition and Cherenkov radiation. In this report, we theoretically investigated the spectral characteristics of radiation produced in both cases when the Tamm–Frank criterion is met or not met. We showed the dependences of the spectrum as a function of thickness and the incidence angle. To describe the properties of polarization radiation and the complex dielectric permittivity, the polarization current approach and Henke’s model were used, respectively.
Analysis of long-term fishing and biological data has made it possible to determine the proportion of respawning individuals (the “remainder”) in populations of Atlantic salmon
Salmo salar
inhabiting ...large rivers of the Kola Peninsula. The contribution of respawning individuals to the dynamics of the Atlantic salmon population was assessed using the mathematical simulation model. It is shown that the model population becomes more resistant to fishing with increase in the “remainder” proportion; however, the influence of such individuals on the population dynamics is noticeable only when their relative number is more than 5% in the spawning population. The results of different model experiments are interpreted. The role of respawning salmons may be determined not so much by their quantitative contribution to the reproduction process as by the maintenance of the genetic diversity of the population within the reproductive strategy characteristic of the Atlantic salmon.
The loess-paleosol sequence exposed in the Beregovoye section (southwest of the Crimean Peninsula) has been thoroughly studied. Detailed analysis of the paleosol morphology, physical properties and ...chemical composition, micromorphology and other characteristics made it possible to identify types of paleosols formed in the Pliocene and Pleistocene. The results obtained gave us an insight into the climate and environments of the past. According to them, the climate of the Pliocene optimum was extremely hot and wet, and the soil zonality was hardly pronounced practically over entire Central and Eastern Europe. At the final phase of the Pliocene the climate became drier, though the rainfall amount was still greater than in the Holocene. During the Early Pleistocene the soil development followed the Mediterranean type, the climate being still warm, though less humid than in the Pliocene. There are two peaks of catastrophic changes in the evolution of the climate and environments distinctly traceable in the Beregovoye section: first – corresponding to the global change recorded between the Pliocene and Pleistocene and second, falling on the initial phase of the modern (Holocene) soil formation.
•There are two peaks of catastrophic changes in the evolution of the climate in the Beregovoye section.•The climate of the Pliocene optimum was extremely hot and wet.•The soil zonality was hardly pronounced over entire Central and Eastern Europe.•At the final phase of the Pliocene the climate became drier.
It was found that new colored ionic organic compounds are formed as a result of the reactions of 2-(4-aryl-5-cyano-2,2′-bipyridin-6(1
H
)-ylidene)malononitriles with triethylamine and pyrrolidine. ...These compounds are stable in air and show solid-state photoluminescence in the green-yellow region of the visible spectrum (λ
em
max
525–565 nm). The photophysical properties of the resulting powders were studied. The position of the emission maximum and the emission intensity depend on the structure of both the cation and the anion. The most intense photoluminescence was observed for the triethylammonium salt containing a methoxy group in the aromatic substituent of the anion. The results obtained can be used to develop a new method for luminescence detection of volatile organic amines.
First results on
-dependence measurements in inclusive
meson production in
interactions (
, Al, Cu, Sn, and W) are presented at
GeV/
c
. The ratios of the differential cross sections of four of these ...nuclei to the differential cross section on aluminum were measured and the dependence of these cross sections on the atomic of the nucleus was studied. The measurements were carried out in the kinematic region of the Feynman variable
and transverse momentum
GeV/
c
.
mesons were detected in the decay mode
at the SPASCHARM experimental setup using negative charged beams at beamline 14 of the U-70 accelerator complex.
Peripheral blood plasma profiles of circulating microRNA expression were analyzed in patients with prostatic cancer and benign hyperplasia. In prostatic cancer, significant increase in hsa-miR-619-5p ...and hsa-miR-1184 microRNA expression and significant decrease in hsalet-7b-5p and hsa-let-7c-5p microRNA expression were observed. The role of the relationship between the microRNA expression and the activities and functions of host genes with introns encoding these microRNA is discussed.
The Vavilov–Cherenkov effect is a well-known phenomenon widely used in various fields, including the diagnostics of charged particle beams. The possibility of separating Vavilov–Cherenkov radiation ...(VCR) and luminescent light is critical for the development of a new generation of optical methods in the diagnostics of low-energy beams. This paper presents the first experimental results on the detection of VCR from an electron beam with an energy of 5.7 MeV passing through diamond and corundum (sapphire) crystals. It is shown that Cherenkov and luminescent light have different glow times for a corundum crystal, while these times are comparable for synthetic diamond. The optical scheme implemented in the experiment, consisting of a filter and a polarizer, also makes it possible to separate Cherenkov and luminescent light. The proposed scheme for detecting VCR will be used to develop a new method for measuring the ion beam energy at the NICA facility (JINR, Dubna, Russia).
Abstract
The Keret River is one of large salmon rivers in the White Sea basin. The estimated abundance of Atlantic salmon in the river began to decrease in 1991, reaching a maximum in 1997 due to the ...abruptly increased illegal fishing level and the invasion of juvenile Atlantic salmon by the monogeny of Gyrodactylus salaris. The studies conducted have shown that the salmon population in the Keret River is depressed and that the average distribution density of juveniles aged 1+ and older is 1.6 fish / 100 m2. Atlantic salmon reproduction on fish hatcheries is important for maintaining the population abundance (farm individuals make up over 50% of the population). Artificial Atlantic salmon reproduction in the Republic of Karelia’s rivers is carried out by the Karelian Branch of Glavrybvod FGBU at the Kem and Vyg fish hatcheries. The fish hatcheries could achieve better results by updating the juvenile breeding technology. An example of a new high-intensity biotechnology is the use of physical factors controlling the vital activity of fish in the various periods of ontogenesis. The study of the effect of low-intensity laser radiation in the early stages of ontogenesis has shown that red light over a certain dose range enhances the adaptability of fish by decreasing mortality and accelerating growth, thus decreasing the loss of fish products in fish hatcheries.
The objectives of the development of reactor technologies for transitioning to two-component nuclear power with thermal and fast reactors as well as the issues arising in the analysis of development ...scenarios, including the uncertainty of the resource base and technical-economic performance, are discussed. It is shown that attempts to detail the structure of the nuclear power system in the second half of the 21st century do not yield unambiguous results, giving compelling reasons for strategic decisions. It is suggested that future work on strategic development be focused on the horizon periods of key decisions concerning the adoption of new reactor technologies.
In the Kola River (Kola Peninsula), on the basis of cluster analysis of long-term density data in the nursery areas of underyearlings, wild and wild + hatchery parr of Atlantic salmon
Salmo salar
L., ...four clusters have been identified in each group of juveniles with high, medium, low, and very low density. In the lower and upper reaches of the river, areas were identified where the state of salmon reproduction can be assessed as critical. The article discusses the role of illegal, unreported, unregulated fishing, ulcerative dermal necrosis and hatchery reproduction as possible reasons for the decline in the reproductive potential of one of the most significant salmon rivers in the region.
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