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L. V. Nikolskaya V. M. Terekhova M. I. Samoilovich 《Physics and Chemistry of Minerals》1978,3(3):213-224
An attempt has been made to interpret natural sapphire optical absorption spectra with regard to the exchange-coupled pairs of iron impurities in their ferric and ferrous states. Level schemes have been calculated for Fe3+-Fe3+ and Fe2+-Fe2+ pairs of all the orders, their symmetry being observed. The selection rules are discussed. EPR and infrared spectroscopy information has been used to assist the optical spectroscopy data. The sapphire color has been interpreted as a function of Fe2+/Fe3+ ratios and of the presence of their pairs in the stone. The various types of charge compensation in Fe2+→Al3+ isomorphism are discussed. 相似文献
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Desiatkin V. D. Kolesnikov A. V. Rimsky A. A. Sysoeva A. O. Terekhova V. A. Kuznetsov N. B. Shazillo A. V. Latysheva I. V. Romanyuk T. V. Fedonkin M. A. 《Doklady Earth Sciences》2021,499(2):643-647
Doklady Earth Sciences - In 2020–2021 the palaeopascichnid fossils were found in the Krasnaya Gorka Site (Shirokovsky Reservoir, Kosva River area, Perm Region), a type Vendian fossil locality... 相似文献
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Starting from Bosma (1981) paper, it was demonstrated by different authors that the observed shape of rotation curves of many spiral galaxies can be explained if to assume that the radial density distribution of the dark matter is correlated with the distribution of HI: the column densities of the dark matter and HI are proportional. We show that this correlation is obviously to be an artifact and can be explained by assuming that the gas surface density is approximately equal or in general proportional to the critical density for the local gravitational stability of gaseous layer. 相似文献
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We present computations of the ionization and thermal balance in the wind from WR and OB stars. The star’s radiation field
is modeled using a Planck function with a temperature from 2 to 6 eV. We assume that the principal contribution from gas heating
and cooling is from ions and atoms of hydrogen, carbon, nitrogen, oxygen, and neon. We take into account photoionization from
the ground state and excited states, ionization by electron collisions, radiative and two-electron recombination, and excitation
and de-excitation of discrete levels by the star’s dilute radiation and electron collisions. It is demonstrated that the thermal
regime of gas in the conditions typical of the winds near WR and OB stars is stable. 相似文献
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The Amur River’s influence on the distribution of the opportunistic bacteria Listeria monocytogenes in the western part of the Sea of Okhotsk is discussed. The presence of Listeria in the seawater, sea ice, and sediments
on the northeastern Sakhalin shelf and slope supports the idea of its connection with the Amur River discharge. The hypothesis
of the allochtonic parentage of L. monocytogenes in the sea’s development is proved. 相似文献
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N. A. Terekhova 《Astronomy Reports》2012,56(7):504-511
We test the hypothesis put forward by Bosma (1981) that the surface density of dark matter is proportional to the surface density of HI, using decompositions of the rotation curves of a number of galaxies according to the THINGS, along with data for the galaxy NGC 6822. The rotation curves of these galaxies can be explained by assuming the existence of a massive gaseous disk in the absence of a dark halo, although the proportionality factor ??dark/??HI between the surface densities of dark matter and HI is different for different galaxies. However, there emerges the problem of the gravitational stability of galaxies whose stellar-velocity dispersions have been estimated, if the thickness of the dark-matter disk is similar to or less than the thickness of the stellar disk. The proportionality between ?? dark and ??HI is probably due to the fact that the radial profiles of ??HI for galaxies with flat rotational curves are close to the critical density of a gravitationally stable gaseous layer (??HI ?? R ?1), and ??dark(R) for a pseudo-isothermal halo obeys the same law. 相似文献
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Water Resources - Taking into account the entire mouth network in its current boundaries, the authors pioneered in representing the historical development of hydrological observations at the... 相似文献
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