41 research outputs found
"Tomography" of the cluster structure of light nuclei via relativistic dissociation
These lecture notes present the capabilities of relativistic nuclear physics
for the development of the physics of nuclear clusters. Nuclear track emulsion
continues to be an effective technique for pilot studies that allows one, in
particular, to study the cluster dissociation of a wide variety of light
relativistic nuclei within a common approach. Despite the fact that the
capabilities of the relativistic fragmentation for the study of nuclear
clustering were recognized quite a long time ago, electronic experiments have
not been able to come closer to an integrated analysis of ensembles of
relativistic fragments. The continued pause in the investigation of the "fine"
structure of relativistic fragmentation has led to resumption of regular
exposures of nuclear emulsions in beams of light nuclei produced for the first
time at the Nuclotron of the Joint Institute for Nuclear Research (JINR,
Dubna). To date, an analysis of the peripheral interactions of relativistic
isotopes of beryllium, boron, carbon and nitrogen, including radioactive ones,
with nuclei of the emulsion composition, has been performed, which allows the
clustering pattern to be presented for a whole family of light nuclei.Comment: ISBN 978-3-319-01076-2. 55 pages, 28 figure
p-i-n фотодиод на основе кремния с малым временем нарастания
Досліджено та проаналізовано фактори, що впливають на час виникнення фотодіоду. Використовуючи отримані результати, був розроблений фотодіод на основі високомічного кремнію провідності p-типу з мінімальним часом підйому. Пропонована конструкція. містить контак т на задній частині кристала фотодіода, який не є безперервним, але має отвір. Такою дірою є проекція світлочутливого елемента на зворотній стороні кристала фотодіоду. Значення часу підйому цього фотодіоду не перевищує 9 нс порівняно з 37 нс у аналозі FD-255A.Исследованы и проанализированы факторы, которые влияют на время нарастания фотодиода. Используя полученные результаты, был разработан фотодиод, основанный на высокоомном кремнии с проводимостью р-типа с минимальным временем нарастания. Предлагаемая конструкция. содержит контакт на задней части кристалла фотодиода, который не является непрерывным, но имеет отверстие. Такая дырка представляет собой проекцию светочувствительного элемента на обратной стороне кристалла фотодиода. Величина времени нарастания этого фотодиода составляет не более 9 нс по сравнению с 37 нс в аналоге FD-255A.The factors that influence the rise time of the photodiode are investigated and analyzed. Using the obtained results, a photodiode based on a high-ohmic silicon of p-type conductivity with a minimized rise time has been developed. The proposed construction. contains a contact on the back of the crystal of a photodiode, which is not continuous, but has a hole. Such a hole is the projection of a photosensitive element on the reverse side of the crystal of a photodiode. The value of the rise time of this photodiode is no more than 9 ns compared to 37 ns in the FD-255 A analogue
Effect of combined oral contraceptives conaining drospirenone + ethinylestradiol on the mammary gland condition in women of reproductive age
Drospirenone, as a part of combined oral contraceptives, has an antiproliferative effect on hyperplastic processes in the organs of the female reproductive system. Individual selection of COCs taking into account the dose and properties of the gestagenic and estrogenic components allows, with contraceptive and non-contraceptive purposes, to prescribe it to women of reproductive age. Intake of COC containing drospirenone + ethinyl estradiol is not associated with impaired drug tolerance due to complaints of soreness and breast engorgement in the first 3 months. 6 months of COCs containing drospirenone + ethinyl estradiol are significantly associated with a decrease in the frequency of clinical and US-signs of dyshormonal dysplasia of the breast. © 2018 Stavropol State Medical University. All rights reserved
Spectral-Kinetic Properties and Energy Transfer in Nanoparticles of Y<inf>0.5–x</inf>Ce<inf>0.5</inf>Tb<inf> x</inf>F<inf>3</inf> Solid Solution
© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Crystalline nanoparticles of Y0.5–xCe0.5TbxF3, doped with various concentrations (x = 0, 0.005, 0.01, 0.05, 0.1, 0.15, and 0.2) of Tb3+ ions were synthesized by co-precipitation. The crystal structure and chemical composition of nanoparticles were studied using transmission electron microscopy, scanning electron microscopy, and X-ray diffractometry. The obtained nanoparticles of solid solutions had an elliptical shape with a size of 10–15 nm along the long axis and good crystallinity with the structure of a CeF3 crystal. The spectral-kinetic properties of the obtained nanoparticles, and the effect of the concentration of Tb3+ activator ions on the energy transfer from Ce3+ to Tb3+ ions were investigated. Energy transfer from Ce3+ to Tb3+ ions in nanocrystals of the Y0.5–xCe0.5TbxF3 solid solutions occurs mainly through the dipole–dipole interaction. The results of evaluating the efficiency of energy transfer from Ce3+ to Tb3+ ions show its increase with increasing concentration of Tb3+ ions
Effect of combined oral contraceptives conaining drospirenone + ethinylestradiol on the mammary gland condition in women of reproductive age
Drospirenone, as a part of combined oral contraceptives, has an antiproliferative effect on hyperplastic processes in the organs of the female reproductive system. Individual selection of COCs taking into account the dose and properties of the gestagenic and estrogenic components allows, with contraceptive and non-contraceptive purposes, to prescribe it to women of reproductive age. Intake of COC containing drospirenone + ethinyl estradiol is not associated with impaired drug tolerance due to complaints of soreness and breast engorgement in the first 3 months. 6 months of COCs containing drospirenone + ethinyl estradiol are significantly associated with a decrease in the frequency of clinical and US-signs of dyshormonal dysplasia of the breast. © 2018 Stavropol State Medical University. All rights reserved
Stability of gold particles in NaY-type zeolites: Promotional effects of co-exchanged metal cations
Shell-type SNRs as sources of cosmic rays
Investigations of VHE gamma-ray sources by any methods, including mirror Cherenkov telescopes, touch on the problem of the cosmic ray origin and, accordingly, the role of the Galaxy in their generation. SHALON observations have yielded results on Galactic supernova remnants (SNR) of different ages. Among them are: the shell-type SNRs Tycho's SNR (1572y), Cas A (1680y), IC 443 (age ∼ (3 ÷ 30) × 103 y), Cygni SNR (age ∼ (5 ÷ 7) × 103 y), G166.0 + 4.3 (age ∼ 24 × 103 y) and the classical nova GK Per (Nova 1901). Observation results are presented for each of the SNRs with spectral energy distributions by SHALON in comparison with other experiment data and images by SHALON together with data from X-rays by Chandra and radio-data by CGPS. The collected experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy 800 GeV–100 TeV gamma-rays in Tycho's SNR, Cas A and IC443. For the first time, unique data on GK Per (Nova1901) TeV gamma-ray emission were obtained with the SHALON experiment. The X-ray data shows that the nova remnant of GK Per could be a younger remnant that will resemble older SNRs like IC 443 which interact with molecular clouds. GK Per is supposed to be a candidate for TeV gamma-ray emission due to accelerated particles in the reverse shock region
Very high energy emission sources beyond the Galaxy
Active Galactic Nuclei (AGN) are considered as potential extragalactic sources of very and ultra high energy cosmic rays. According to theoretical predictions cosmic ray acceleration can take place at the shock created by the expanding cocoons around active galactic nuclei as well as at AGN jets. The measurements of AGN TeV spectra, the variability time scale of TeV emission can provide essential information on the dynamics of AGN jets, the localization of acceleration region and an estimation of its size. SHALON observations yielded data on extragalactic sources of different AGN types in the energy range of 800 GeV–100 TeV. The data from SHALON observations are compared with those from other experiments at high and very high energies