146 research outputs found
Представники роду Pinus L. у ландшафтах дендропарку “Тростянець”
It is presented the short historical data on an introduction, taxonomic structure of the representatives of the genus of Pіnus L., tested in dendropark Trostjanets during the different periods of its existence. The decorative and age condition and the reproductive ability of separate representatives of this genus in conditions of dendropark and their use in park landscapes were investigated.Наведено короткі історичні відомості про інтродукцію і таксономічну структуру представників роду Pinus L., випробуваних у дендропарку “Тростянець” у різні періоди його існування. Досліджено декоративний та віковий стан, репродуктивну спроможність окремих представників роду в умовах дендропарку та використання їх у паркових ландшафтах
Experimental test of the probability density function of true value of Poisson distribution parameter by single observation of number of events
The empirical probability density function for the conditional distribution
of the true value of Poisson distribution parameter on one measurement is
constructed by computer experiment. The analysis of the obtained distributions
confirms that these distributions are gamma-distributions.Comment: presented in the IX International Workshop on Advanced Computing and
Analysis Techniques in Physics Research (ACAT'03), KEK, Tsukuba, Japan,
December 1-5, 200
Phosphorus-based compounds for EUV multilayer optics materials
We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were considered for applications as reflector materials. Our calculations for multilayer structures with perfect interfaces show that the Pd/BP material combination suggests the highest reflectivity values, exceeding 70% within the 9.2 – 10.0 nm spectral range. We also discuss the potential of fabrication of BP-based multilayer structures for optical applications in the extreme ultraviolet rang
Deposition of refractory metal films with planar plasma ECR source
The condition of the deposition of refractory metal and alloy films such as W, Mo, Ti, Ta, Cr, Ni, Fe₈₀B₂₀ with using ECR plasma source at the different magnitudes of bias voltage on targets and substrates were investigated. It was revealed that the maximal rate of the films growth amounted to 0,052 µm/min for Cr. The thicknesses of the films were obtained of 16-20 µm in the current experiments.Досліджено умови нанесення покритій тугоплавких металів, таких як W, Mo, Ti, Ta, Cr, Ni, а також сплава Fe₈₀B₂₀ з використанням ЕЦР плазмового джерела при різних величинах напруги на мішені та підкладці. Показано, що максимальна швидкість росту товщини покриття складала 0,052 мкм/хв для Cr. В даних експериментах були отримані покриття товщиною порядку 16 - 20 мкм.Исследованы условия нанесения покрытий тугоплавких материалов, таких как W, Mo, Ti, Ta, Cr, Ni, а также сплава Fe₈₀B₂₀ с использованием ЭЦР плазменного источника при различных величинах смещения напряжения на мишени и подложке. Показано, что максимальная скорость роста толщины покрытия составляла 0,052 мкм/мин для Cr. В данных экспериментах были получены покрытия толщиной порядка 16 - 20 мкм
Nanostructured metal-fullerene field emission cathode
One of the important properties of carbon nanostructures is their cold electron
emission ability. Carbon nanotubes and other nanostructures are capable of
emitting high currents at relatively low electrical fields. They are already
used in functional devices such as field emitters. The conventional method of
carbon nanostructured cathodes manufacturing is thin film nanocarbon deposition
using CVD process on electrically conducting substrate like metal or doped
silicon plates. The alternative way of manufacturing of carbon field emission
cathodes is based on a special processing of carbon microfibers or composite materials in metal holders. We used the similar approach to produce composite
metal-nanocarbon material which may be easily processed and shaped to
produce an effective field emission cathode which can be easily fixed an any
environment.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2058
Properties of Zirconia Nanoceramics under High-Energy Electrons Irradiation
Formation of radioactive isotopes is investigated under irradiation by relativistic electrons with energy
up to 100 MeV. Radioactive isotopes 87,88Y, 88,89,95Zr, 95Nb, 175Hf are registered after irradiation by
relativistic electrons with energy 47.2 MeV. The present data are necessary for the choice of a material for
a dielectric wakefield accelerator. The greatest danger at operation of accelerators represents 88Y.
Formation of radiation defects in nanoceramics is investigated. The various types of radiation defects are
found out at an irradiation by relativistic electrons with energy 47 MeV and 86 MeV. In UV VIS spectra
the absorption lines of radiation are registered at 402.2 nm and 635 nm, which correspond to the F and F'
centers of monocline lattices of zirconia. It is revealed, that krypton atoms are the centers of segregation of
point defects.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3562
The study of the negative pion production in neutron-proton collisions at beam momenta below 1.8 GeV/c
A detailed investigation of the reaction np -> pp\pi^{-} has been carried out
using the data obtained with the continuous neutron beam produced by charge
exchange scattering of protons off a deuterium target. A partial wave
event-by-event based maximum likelihood analysis was applied to determine
contributions of different partial waves to the pion production process. The
combined analysis of the np -> pp\pi^{-} and pp -> pp\pi^{0} data measured in
the same energy region allows us to determine the contribution of isoscalar
partial waves (I=0) in the momentum range from 1.1 up to 1.8 GeV/c. The decay
of isoscalar partial waves into (^1S_0)_{pp}\pi$ channel provides a good tool
for a determination of the pp S-wave scalar scattering length in the final
state which was found to be a_{pp}=-7.5\pm 0.3 fm.Comment: 6 pages, 6 figure
Ground states of a one-dimensional lattice-gas model with an infinite range nonconvex interaction. A numerical study
We consider a lattice-gas model with an infinite range pairwise noncovex
interaction. It might be relevant, for example, for adsorption of alkaline
elements on W(112) and Mo(112). We study a competition between the effective
dipole-dipole and indirect interactions. The resulting ground state phase
diagrams are analysed (numerically) in detail. We have found that for some
model parameters the phase diagrams contain a region dominated by several
phases only with periods up to nine lattice constants. The remaining phase
diagrams reveal a complex structure of usually long periodic phases. We also
discuss a possible role of surace states in phase transitions.Comment: 16 pages, 5 Postscript figures; Physical Review B15 (15 August 1996),
in pres
LED Monitoring System for the BTeV Lead Tungstate Crystal Calorimeter Prototype
We report on the performance of a monitoring system for a prototype
calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled
with photomultiplier tubes. The tests were carried out at the 70 GeV
accelerator complex at Protvino, Russia.Comment: 12 pages, 8 figures, LaTeX2e, revised versio
HIgh heat flux plasma testing of ITER divertor materials under ELM relevant conditions in QSPA Kh-50
Performed studies of plasma-surface interaction include measurements of plasma energy deposited to the material surface and determination of tungsten cracking threshold during repetitive ITER ELM-like plasma exposures in QSPA Kh-50 with plasma pulses of energy density up to 2.5 MJ/m2 and duration of 0.25 ms. The energy threshold for tungsten cracking development is found to be ~0,3 MJ/m2. The Ductile-to-Brittle Transition Temperature (DBTT) is experimentally estimated for ITER relevant tungsten grade. Major crack network (cells size up to 1.3 mm) forms only in cases of initial target temperatures below DBTT. Intergranular micro-cracks network (size of cells corresponds to the grain size) appears under heat loads after melting threshold
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