New data on the geological structure of the junction between the Cape Verde Seamount and the Cape Verde Basin, central Atlantic     

S. G. Skolotnev  A. A. Peive  N. N. Turko  N. V. Tsukanov  L. A. Golovina  V. N. Efimov  A. E. Eskin  V. Yu. Lavrushin  V. V. Petrova  N. L. Chaplygina 《Doklady Earth Sciences》2006,407(1):220-224

  相似文献   

Isotopic-geochemical signs of the transformation of coal and bitumen during the ore mineralization of different types: Communication 2. Geochemical regularities in the distribution of rare earth and trace elements supplemented with the model of structural transformation of coal and bitumen during ore genesis     

E. D. Syngaevskii  Yu. V. Shchegol’kov  G. Ch. Vichtozhents  G. K. Khachatryan  S. N. Petrova 《Lithology and Mineral Resources》2007,42(6):572-583

Regularities in the distribution of rare-earth and trace elements in organic matter depending on geological settings and geochemical processes are considered. The model of transformation of organic matter and redistribution of ore elements during oil generation and ore formation is discussed.  相似文献   

New Trends in the Development of the Lunar Physical Libration Theory   总被引：4，自引：0，他引：4  

Natalya Petrova  Alexand er Gusev 《Celestial Mechanics and Dynamical Astronomy》2001,80(3-4):215-225

A review of the modern state of the lunar libration theory is presented. A significant progress in the lunar investigation is achieved due to the simultaneous processing of results of the satellite Doppler tracing and of the lunar laser ranging. The data evidencing existence of a small iron core in the Moon are discussed. In this connection, the further development of the theory of rotation of the Moon presents the study of internal structure and dynamics of a lunar body. A model of a two-layer Moon can have a very advanced application to explain some observed phenomena and to be as a first approach in the modelling of internal processes determining the lunar rotation.  相似文献   

Magnetisation of titanomagnetites from Bulgarian basalts     

G.N. Petrova  O.L. Bagina 《Physics of the Earth and Planetary Interiors》1982,30(4):274-280

A number of basalt samples containing titanomagnetites, with varying degrees and modes of oxidation, have been collected from 13 sites in northern Bulgaria, the degree of oxidation being determined from Curie point and lattice parameter determination. The stability of natural remanent magnetization and artificially induced thermoremanences (TRM) has been studied in an attempt to determine whether the oxidized rocks carry a TRM inherited from their original, unoxidized state. From the samples studied, it appears that the intensity and direction of the original TRM's are retained, but that there is some loss in stability.  相似文献   

On the Circular Polarization of Pulsar Radiation     

Y.E. Lyubarskii  S.A. Petrova 《Astrophysics and Space Science》1998,262(4):379-389

We consider the polarization behaviour of radio waves propagating through an ultrarelativistic highly magnetized electron-positron plasma in a pulsar magnetosphere. The rotation of magnetosphere gives rise to the wave mode coupling in the polarization-limiting region. The process is shown to cause considerable circular polarization in the linearly polarized normal waves. Thus, the circular polarization observed for a number of pulsars, despite the linear polarization of the emitted normal waves, can be attributed to the limiting-polarization effect. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Masses and ages of delta scuti stars in eclipsing binary systems     

Ts. G. Tsvetkov  Ts. C. Petrova 《Astrophysics and Space Science》1993,203(2):257-266

By using data mainly from Frolovet al. (1982) for four Delta Scuti stars in eclipsing binary systems, AB Cas, Y Cam, RS Cha, and AI Hya, their physical parameters, distances, and radial pulsation modes are determined. The evolutionary track systems of Iben (1967), Paczyski (1970), and Maeder and Meynet (1988) are interpolated, in order to estimate evolutionary massesM _eand agest of these variables. Their pulsation massesM _Qare estimated from the fitting formulae of Faulkner (1977) and Fitch (1981). Our estimates of evolutionary massesM _eand pulsation massesM _Qare close to the massesM determined by Frolovet al. (1982) from the star binarity. The only exception is AB Cas, for which there is no agreement between certain star parameters.Another, independent approach is also applied to the stars RS Cha and AI Hya: by using their photometric indicesb — y andc ₁ from the catalogue of López de Cocaet al. (1990) and appropriate photometric calibrations, other sets of physical parameters, distances, modes, ages, evolutionary and pulsation masses of both variables are obtained.  相似文献   

Water Pollution by Heavy Metals and Oil Products in Uglovoi Bay in February 2010–2016     

Petukhov  V. I.  Petrova  E. A.  Losev  O. V. 《Water Resources》2019,46(1):103-111

Water Resources - Water pollution by heavy metals in Uglovoi Bay in 2015–2016 was analyzed. The concentrations of Mn, Fe, Cu, Ni, Hg, As, Pb, Cd, and oil products were found to exceed the...  相似文献   

Annama H chondrite—Mineralogy,physical properties,cosmic ray exposure,and parent body history          下载免费PDF全文

Tomáš Kohout  Jakub Haloda  Patricie Halodová  Matthias M. M. Meier  Colin Maden  Henner Busemann  Matthias Laubenstein  Marc. W. Caffee  Kees C. Welten  Jens Hopp  Mario Trieloff  Ramakant R. Mahajan  Sekhar Naik  Josep M. Trigo‐Rodriguez  Carles E. Moyano‐Cambero  Michael I. Oshtrakh  Alevtina A. Maksimova  Andrey V. Chukin  Vladimir A. Semionkin  Maksim S. Karabanalov  Israel Felner  Evgeniya V. Petrova  Evgeniia V. Brusnitsyna  Victor I. Grokhovsky  Grigoriy A. Yakovlev  Maria Gritsevich  Esko Lyytinen  Jarmo Moilanen  Nikolai A. Kruglikov  Aleksey V. Ishchenko 《Meteoritics & planetary science》2017,52(8):1525-1541

The fall of the Annama meteorite occurred early morning (local time) on April 19, 2014 on the Kola Peninsula (Russia). Based on mineralogy and physical properties, Annama is a typical H chondrite. It has a high Ar‐Ar age of 4.4 Ga. Its cosmic ray exposure history is atypical as it is not part of the large group of H chondrites with a prominent 7–8 Ma peak in the exposure age histograms. Instead, its exposure age is within uncertainty of a smaller peak at 30 ± 4 Ma. The results from short‐lived radionuclides are compatible with an atmospheric pre‐entry radius of 30–40 cm. However, based on noble gas and cosmogenic radionuclide data, Annama must have been part of a larger body (radius >65 cm) for a large part of its cosmic ray exposure history. The ¹⁰Be concentration indicates a recent (3–5 Ma) breakup which may be responsible for the Annama parent body size reduction to 30–35 cm pre‐entry radius.  相似文献   

A novel look at the pulsar force-free magnetosphere     

S. A. Petrova  A. B. Flanchik 《Astrophysics and Space Science》2018,363(3):51

The stationary axisymmetric force-free magnetosphere of a pulsar is considered. We present an exact dipolar solution of the pulsar equation, construct the magnetospheric model on its basis and examine its observational support. The new model has toroidal rather than common cylindrical geometry, in line with that of the plasma outflow observed directly as the pulsar wind nebula at much larger spatial scale. In its new configuration, the axisymmetric magnetosphere consumes the neutron star rotational energy much more efficiently, implying re-estimation of the stellar magnetic field, \(B_{\mathrm{new}}^{0}=3.3\times10^{-4}B/P\), where \(P\) is the pulsar period. Then the 7-order scatter of the magnetic field derived from the rotational characteristics of the pulsars observed appears consistent with the \(\cot\chi\)-law, where \(\chi\) is a random quantity uniformly distributed in the interval \([0,\pi/2]\). Our result is suggestive of a unique actual magnetic field strength of the neutron stars along with a random angle between the magnetic and rotational axes and gives insight into the neutron star unification on the geometrical basis.  相似文献   

Characterization of the matrix and fusion crust of the recent meteorite fall Ozerki L6     

A. A. Maksimova  E. V. Petrova  A. V. Chukin  M. S. Karabanalov  I. Felner  M. Gritsevich  M. I. Oshtrakh 《Meteoritics & planetary science》2020,55(1):231-244

We studied the interior and the fusion crust of the recently recovered Ozerki L6 meteorite using optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy, X‐ray diffraction (XRD), magnetization measurements, and Mössbauer spectroscopy. The phase composition of the interior and of the fusion crust was determined by means of SEM, XRD, and Mössbauer spectroscopy. The unit cell parameters for silicate crystals were evaluated from the X‐ray diffractograms and were found the same for the interior and the fusion crust. Magnetization measurements revealed a decrease of the saturation magnetic moment in the fusion crust due to a decrease of Fe‐Ni‐Co alloy content. Both XRD and Mössbauer spectroscopy show the presence of magnesioferrite in the fusion crust. The temperatures of cation equilibrium distribution between the M1 and M2 sites in silicates calculated using the data obtained from XRD and Mössbauer spectroscopy appeared to be in a good consistency: 553 and 479 K for olivine and 1213 and 1202 K for orthopyroxene.  相似文献