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41.
N. P. Burkovskaya E. V. Orlova M. A. Kiskin N. N. Efimov A. S. Bogomyakov M. V. Fedin S. V. Kolotilov V. V. Minin G. G. Aleksandrov A. A. Sidorov V. I. Ovcharenko V. M. Novotortsev I. L. Eremenko 《Russian Chemical Bulletin》2011,60(12):2490-2503
Trinuclear heterometallic complexes containing the {M2Ln(Piv)6(NO3)} (MII = Ni, Cu; LnIII = Nd, Pr, Sm, Eu, Gd; Piv? is the anion of pivalic acid) and {Cu2Ln(Piv)8)]? (LnIII = Eu, Gd) metal cores were synthesized, their structures and magnetic properties were studied. For the most compounds, it was shown that their magnetic properties can be interpreted taking no interaction of the 3d-metal ions and a lanthanide into account. Ferromagnetic exchange interactions were found to exist between the unpaired electrons of the paramagnetic centers in the exchange clusters of the gadolinium-containing heterometallic complexes {M-Gd-M} (M = Ni or Cu). 相似文献
42.
I Starke G Sarodnick V V Ovcharenko K Pihlaja E Kleinpeter 《Rapid communications in mass spectrometry : RCM》2002,16(3):169-175
The electron impact (EI) mass spectra of 34 differently substituted 2-phenoxymethyl-, 2-naphthyloxymethyl-, 2-pyridinyloxymethyl- and 2-chinolinyloxymethylquinoxalines were recorded. The fragmentation patterns were examined by metastable ion analysis and exact mass measurements, employing finally also selective deuterium labelling. The inclusion of the substituted aryl ring moiety appears to be important for the fragmentation of the aryloxymethylquinoxalines. A molecular ion rearrangement is proposed for the observed loss of OH* and CHO* radicals. The influence of the different substituents on the aryl ring moiety on the rearrangement in the gas phase and on the resulting fragmentation was investigated. 相似文献
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44.
Yu. A. Osip’yan R. B. Morgunov A. A. Baskakov V. I. Ovcharenko S. V. Fokin 《Physics of the Solid State》2003,45(8):1465-1470
Jumplike changes in the microhardness, sample dimensions, and parameters of the EPR spectrum were observed in molecular Cu(hfac)2LEt crystals undergoing a phase transition. Defects that appear upon plastic deformation (e.g., dislocations) and paramagnetic defects were revealed. The latter defects are likely breaks in polymer chains and can serve as spin marks for investigating the magnetic state of the crystal lattice. 相似文献
45.
Basalt fibers are efficient reinforcing fillers for polypropylene because they increase both the mechanical and the tribotechnical properties of composites. Basalt fibers can compete with traditional fillers (glass and asbestos fibers) of polypropylene with respect to technological, economic, and toxic properties. The effect of technological parameters of producing polypropylene-based basalt fiber-reinforced plastics (BFRPs) by combined extrusion on their mechanical properties has been investigated. The extrusion temperature was found to be the main parameter determining the mechanical properties of the BFRPs. With temperature growth from 180 to 240°C, the residual length of the basalt fibers in the composite, as well as the adhesive strength of the polymer-fiber system, increased, while the composite defectiveness decreased. The tensile strength and elastic modulus increased from 35 to 42 MPa and 3.2 to 4.2 GPa, respectively. At the same time, the growth in composite solidity led to its higher brittleness. Thus, a higher temperature of extrusion allows us to produce materials which can be subjected to tensile and bending loads, while the materials produced at a lower temperature of extrusion are impact stable. The effect of the gap size between the extruder body and moving disks on the mechanical properties of the BFRPs is less significant than that of temperature. An increase of the gap size from 2 to 8 mm improves the impregnation quality of the fibers, but the extruder productivity diminishes. The possibility of controling the properties of reinforced polypropylene by varying the technological parameters of combined extrusion is shown. The polypropylene-based BFRPs produced by the proposed method surpass the properties of glass and asbestos fiber-reinforced plastics.Submitted to the 10th International Conference on Mechanics of Composite Materials (Riga, April 20–23, 1998).Ukrainian State University of Chemical Technology, Dnepropetrovsk, Ukraine. Translated from Mekhanika Kompozitnykh Materialov, Vol. 33, No. 6, pp. 845–850, November–December, 1997. 相似文献
46.
A. A. Belyanin V. V. Kocharovsky VI. V. Kocharovsky 《Radiophysics and Quantum Electronics》1996,41(1):22-27
It is believed that the detection of gamma-ray bursts from evaporating primordial black holes is highly improbable in the
near future since the expected photon flux, consisting mainly of photons with energies ≳ GeV, is too low. Contrary to this
point of view, we show that a large fraction of the black hole power at the final stage of evaporation (the last 103 s) can be liberated as a burst of soft γ-ray emission of duration 10−1–103 s and luminosity 1028–1031 erg/s in the energy range 0.1–1 MeV. According to our calculations of the black hole evaporation rate (within the Standard
Model of elementary particles), when the black hole temperature exceeds approximately 10 GeV, the charged particle outflow
from a black hole forms a well-defined plasma and can be described in the hydrodynamic approximation. In this case more than
half of the rest energy of a black hole can be converted into soft gamma-rays due to the presence of the magnetic field with
energy density comparable to that of charged particles. We consider various mechanisms leading to such transformation and
estimate their efficiency. It is shown that, at least, some of the gamma-ray bursts detected by BATSE can be associated with
evaporating black holes.
Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh
Zavedenii, Radiofizika, Vol. 41, No. 1, pp. 36–45, January, 1998. 相似文献
47.
L. Rosenthaler P. Krumholz J. Vasquez Sanchez F. Feigl A. S. Komarowsky N. S. Poluektoff J. V. Dubský J. Trtilek A. Oká G. Hellsing K. Heumann F. Emich Olga S. Fedorova Georges Glomaud J. Trtílek VI. Stanék T. Nemes Carl Urbach R. Baril und J. H. Yoe 《Fresenius' Journal of Analytical Chemistry》1935,102(7-8):280-289
Ohne Zusammenfassung 相似文献
48.
G. P. Bakach E. F. Dudarev T. Yu. Chubenko V. E. Ovcharenko V. P. Lyubivoi E. G. Barmina 《Russian Physics Journal》1993,36(12):1135-1140
We have studied the influence of boron on the plasticity and strength of the intermetallic compound Ni3Al at stoichiometric and nonstoichiometric compositions, grown by self-propagating high temperature synthesis. We have determined the nature of the fracture and the fraction of brittle intercrystallite and viscous transcrystallite fracture. A correlation is found between the low temperature plasticity and the fraction of transcrystallite fracture. It is shown that the addition of boron, up to its solubility increases the cohesive strength of the grain boundaries in melts at the stoichiometric and nonstoichiometric compositions. In a melt with 25 at. % Al it remains about two times smaller than in a melt with 24 at. % Al.V. D. Kuznetsova Physicotechnical Institute at Tomsk University, Siberia. Institute for the Physics of Strength and Materials Fabrication, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 47–53, December, 1993. 相似文献
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