Composites of a heterospin molecular magnet Eu(III)(SQ)
3
bipy in a polystyrene (PS) matrix have been synthesized. The EuIII(SQ)
3
bipy complex contains four paramagnetic centers—the Eu
3+
ion and ...three SQ ligands (SQ-3,6-di-tert-butyl benzoquinone radical anion); bipy (bipyridyl) is diamagnetic. It has been established that intensive mechanical activation of Eu(III)(SQ)
3
bipy/PS samples leads to a rheological explosion, as a result of which radio frequency superradiance, the appearance of free electrons and the formation of Eu metal nanoparticles are observed. The duration of this process is 10 ns.
Plasma decay in the afterglow of a repetitively pulsed nanosecond discharge in a stoichiometric propane–oxygen mixture was experimentally investigated when a weak heating DC electric field was ...applied and in its absence. The discharge was ignited at room gas temperature and a pressure of 1–2 Torr and was characterized by low specific energy inputs (<0.004 eV per molecule in one pulse). Using microwave interferometry, the temporal evolution of the electron density during plasma decay was studied, and the effective recombination coefficients were obtained from data processing. It was shown that the rate of plasma decay behaved in a non-monotonic manner with increasing degree of propane oxidation; at first the decay rate grew, then passed through a maximum, fell and saturated in the limit of a large (~2000) number of pulses. In this limit, the effect of the heating DC electric field on the plasma decay decreased with approaching chemical equilibrium. Numerical simulation of the observed effects was performed for low and high oxidation degrees of propane taking into account changes in the composition of positive ions in the plasma. Good agreement was obtained between measurements and calculations of the electron density during plasma decay in these cases. It was shown that the formation of cluster ions in the discharge afterglow plays a fundamental role. The plasma decay was controlled by electron recombination with hydrocarbon cluster ion at low oxidation degree of propane and with water cluster (hydrated) ions at high oxidation degree. A hypothesis was proposed to explain the observed nonmonotonic behavior of the plasma decay rate with an increase in the propane oxidation in the discharge, based on the formation of hydrated hydrocarbon ions CxHy+(H2O)k at moderate oxidation degrees.
Using a numerical solution of the Boltzmann equation, the electron drift velocity, the coefficients of their longitudinal and transverse diffusion, as well as the ionization and dissociative ...attachment coefficients in weakly ionized plasma of mixtures of air with water vapor are calculated in a wide range of reduced electric fields (1–650 Td, 1 Td = 10
–17
V cm
2
) and mole fractions of water vapor (0–1). The calculation results are compared with new experimental data, and good agreement between them is obtained. It is shown that for all coefficients and the average electron energy, their dependence on the gas composition changes with increasing electric field. At low reduced fields, an increase in the content of H
2
O water molecules in mixtures leads to a decrease in the transport coefficients and average electron energy, while the opposite trend is observed at high fields. It is shown that for the drift velocity and electron attachment coefficient there are electric fields, in which these coefficients in gas mixtures can be greater than the coefficients in dry air and water vapor. A qualitative explanation is given for the obtained dependences of the electron coefficients on the electric field and H
2
O content in the mixtures.
The effect of mechanical activation of radiofrequency superradiance in a composite based on a heterospin molecular magnet and a polystyrene matrix has been established. Mechanical activation was ...carried out for the first time in the rheological explosion unloading mode.
A neutron collimator is developed to attenuate the neutron flux and reduce the residual induced activity in the interportal space of the diagnostic system of neutral particle analyzers of the ITER ...tokamak reactor. The collimator is installed in the port plug of the ITER vacuum vessel in front of an inlet to the vacuum pipeline of the diagnostic system. The collimator design has a cellular structure with 80% transparency for the neutral atom beam that goes out of the plasma and is recorded by the analyzers. However, because of increased scattering of neutrons in the collimator, their flux in the interportal room in the service zone of diagnostic systems of equatorial port no. 11 is significantly reduced and allows the equivalent dose rate in this zone to be decreased by several times. Thermal analysis showed that, during the reactor operation in modes with generation of the maximum power of 500 MW, the plasma radiation will cause the heating of the collimating grid to a temperature not exceeding 250°C, which makes it possible to select the stainless steel (316L(N)-ITER grade) as a material for manufacturing the collimator. In this case the cyclic strength of the collimator meets the ITER requirements, and it can be used without replacement during the entire deuterium-tritium experiment of the tokamak reactor.
The Russian Academy of Sciences and Federal Space Agency, together with the participation of many international organizations, worked toward the launch of the RadioAstron orbiting space observatory ...with its onboard 10-m reflector radio telescope from the Baikonur cosmodrome on July 18, 2011. Together with some of the largest ground-based radio telescopes and a set of stations for tracking, collecting, and reducing the data obtained, this space radio telescope forms a multi-antenna ground-space radio interferometer with extremely long baselines, making it possible for the first time to study various objects in the Universe with angular resolutions a million times better than is possible with the human eye. The project is targeted at systematic studies of compact radio-emitting sources and their dynamics. Objects to be studied include supermassive black holes, accretion disks, and relativistic jets in active galactic nuclei, stellar-mass black holes, neutron stars and hypothetical quark stars, regions of formation of stars and planetary systems in our and other galaxies, interplanetary and interstellar plasma, and the gravitational field of the Earth. The results of ground-based and inflight tests of the space radio telescope carried out in both autonomous and ground-space interferometric regimes are reported. The derived characteristics are in agreement with the main requirements of the project. The astrophysical science program has begun.
A new study of a historical object on the territory of the Russian Federation, the Holy Trinity Danilov Monastery, implemented by the muon radiography is presented. The method is based on the ...registration of changes in the cosmic muon fluxes during their passage through the object under study. Nuclear photoemulsions with unique spatial and angular resolution having the widest range of applications in experimental nuclear physics were used as experimental equipment. The experiment demonstrates a high efficiency of the method in the search for hidden objects, the presence of which on the territory of the monastery is confirmed by the results obtained.
New trinuclear Cd–Ln molecular complexes EuCd
2
(O
2
CC
6
F
5
)
6
(NO
3
)(Bipy)
2
(
I
, Bipy is 2,2'-bipyridine) and LnCd
2
(Bzo)
6
(NO
3
)(Phen)
2
· 4MeCN (Ln = Tb (
II)
, Eu (
III
), Bzo is anion ...of 3,5-di-
tert
-butylbenzoic acid, Phen is 1,10-phenanthroline) are studied. Their structures are determined by X-ray structure analysis (СIF files CCDC nos. 1938125 (
I
), 1938124 (
II
)) or by X-ray diffraction analysis (
III
), and the photoluminescence properties are studied. The reactions of complexes
I
and
II
with terephthalic acid (H
2
Bdc) are accompanied by the destruction of the heterometallic molecules to form 2D coordination polymers Cd
3
(Bbdc)
3
(Bipy)
2
3
n
· 4
n
MeCN ·
n
H
2
O (
IV
) and Cd
2
(Bdc)
2
(Phen)
2
n
· 2
n
DMF (
V
) (СIF files CCDC nos. 1938126 and 1937492, respectively).
The solvent extraction of the
90
Y/
90
Sr pair from carbonate media with mixtures of aromatic dihydroxy compounds and a quaternary ammonium salt—methyltrioctylammonium carbonate (MTOAC)—in toluene ...and butyl acetate was studied. It was found that MTOAC increases the distribution coefficients of both the extractant itself and its solvate with yttrium due to the formation of a mixed complex of yttrium and a dihydroxyaromatic ligand with MTOAC. During extraction from alkaline carbonate media in the pH range of 12–13.5 with mixtures of 0.01 M 2,3-dihydroxynaphthalene and 0.015 M MTOAC in butyl acetate or toluene, the distribution coefficients of yttrium exceed 80; the separation factors of the
90
Y/
90
Sr pair under these conditions are more than 10
5
. Dilute solutions of hydrochloric, nitric, and sulfuric acids can be used for the complete stripping of yttrium. The studied mixtures are chemically stable and do not change the extraction properties upon multiple extraction/stripping cycles. Model experiments on the leaching of yttrium from natural samples showed that the percentage of stable yttrium extraction from sand is 70–80%, while the percentage of yttrium extraction from soil is 50–60%.
The intensity of the interaction between a helium cold atmospheric plasma jet (CAPJ) and a dielectric surface or animal skin is compared in experiment and numerical simulation. A cold plasma jet at ...atmospheric pressure is generated by a sinusoidal or positive pulsed voltage with different pulse durations in optimal modes. The impact effect is estimated on the basis of measured and calculated currents, line intensities in the CAPJ spectrum and temperature fields. The measured CAPJ characteristics show that the pulsed voltage for the CAPJ excitation is preferable compared to the sinusoidal mode. Varying the pulse duration of the periodic pulsed voltage makes it possible to obtain the maximum current and electric field strength at the surface within the permissible temperature in the contact area of the CAPJ with the skin of mice (<42°C). It is shown that the results of the CAPJ study obtained in physical experiments using a dielectric plate are applicable for tumor-bearing mice treatment.
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