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1.
VI. Sedláček 《Czechoslovak Journal of Physics》1988,38(5):465-469
The formation of slip bands is the main mechanism of cyclic deformation in pure Al. Their density, orientation and heights in polycrystalline Al were investigated during cycling. Types, sizes and densities of precipitates are responsible for the mode of cyclic deformation in AlCu4 pure alloy. In technical Al alloys intermetallic phases have detrimental effects on deformation homogeneity and largely govern the fatigue mechanism of the material and especially microcrack initiation. 相似文献
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The absorbance signal in electrothermal atomic absorption spectrometry is a result of the processes of atom formation and dissipation and first of all depends on the initial generation of atoms from the surface. The rising part of the absorbance time profiles can be used for characterization of the release of the metals like Pd, Ag, Au etc. The method is applied to investigate the palladium release from a pyrocoated graphite support at different initial masses of the Pd. The kinetic parameters are evaluated and conclusions about the distribution of palladium on the graphite surface are made. The estimated values of apparent activation energies depend on the initial mass of analyte. The advantages and limitations of the present approach are discussed. 相似文献
4.
A method for evaluating Ea(loss), the apparent activation energy of the analyte loss process during the high-temperature thermal pretreatment stage in electrothermal atomization atomic absorption spectrometry (ETA-AAS) has been developed. The method is based on extracting information from the declining portion of thermal pretreatment curves (in this case presented as absorbance vs pyrolysis time at various fixed temperatures). Five volatile analytes (As, Pb, Sb, Se, and Sn) have been studied in the presence of tungsten chemical modifier (20 μg of W in H2O2). The data on Ea (loss) have been utilized together with those obtained from treating the atomization peaks Ea and with literature data on known values of bond energies and enthalpies of certain chemical reactions. Possible mechanisms of analyte losses and atomization are discussed. 相似文献
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Electrothermal atomic absorption spectrometry is applied to investigate the release of the selenium and tin atoms from pyrocoated
graphite support. The Coats and Redfern and Sturgeon approaches are used for estimation of the apparent activation energies
of atom release. The addition of tungsten and palladium modifiers leads to enhancement of the activation energies and changes
the kind of the vaporizing species for analytes. 相似文献
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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
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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
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J. Badalec J. Ďatlov K. Jakubka VI. Kopecký Š. Körbel L. Kryška P. Magula J. Stöckel F. Žáček S. Nanobashvili 《Czechoslovak Journal of Physics》1983,33(7):787-790
The work is devoted to the study of the LH wave effect on the peripheral plasma of the TM-1-MH tokamak. The observed enhancement of the ion saturated current in the limiter shadow is interpreted as heating of the peripheral ions by absorption of decay waves generated in this region due to the nonlinear wave-plasma interaction. 相似文献
9.
S. I. Sidorenko A. M. Taratin S. A. Vorob'ev P. A. Kotsyumakha A. I. Kurlat B. M. Sobishchanskii A. G. Khotchenkov B. F. Minaev S. I. Galko E. A. Vasil'kovskaya V. V. Gorskii V. M. Lisitsyn A. Z. Éfendiev A. M. Yunusov S. A. Sadykov A. A. Aliverdiev T. A. Borodina T. S. Minakova V. I. Perov Yu. A. Tisenko Z. F. Dmitrenko V. V. Mikho V. Ya. Galin Yu. S. Makushkin A. I. Petrova VI. G. Tyuterev A. G. Yakunin G. A. Korablev 《Russian Physics Journal》1977,20(8):1116-1122
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VI. Nevoral 《Analytical and bioanalytical chemistry》1974,268(3):189-193
In the described analysis of mineral waters, after the throughflow of the sample through a column with Dowex 50 WX 12 in H+ form, the main cations are first eluted by 1.6 N HCl and then the rare earths by 6 N HCl. The latter are separated by ion-exchange chromatography on Dowex 50WX8 in NH4 + form, the elution being performed with ammonium citrate pH 4.19. The presence of rare earths in the eluate was ascertained spectrophotometrically by means of their reaction with xylenol orange in the presence of cetylpyridinium bromide. In mineral waters from the West-Bohemian spa region it was possible to find traces of trivalent La, Ce, Pr, Nd, Sm + Gd, Y, Dy, Ho, Er, Tm, Yb and Lu. 相似文献