First evidence for concentrations of transuranium curium in the Yenisei floodplain ecosystem     

A. Ya. Bolsunovsky  A. I. Ermakov  A. I. Sobolev  A. G. Degermendzhi 《Doklady Earth Sciences》2006,409(5):810-813

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Simulation of triggered earthquakes in the laboratory     

G. A. Sobolev  A. V. Ponomarev  A. V. Koltsov  V. B. Smirnov 《Pure and Applied Geophysics》1996,147(2):345-355

The experiments were conducted for the study of stick-slip at the contact between two granite blocks. Three cases were studied under the following conditions: 1) the increase of load at a constant rate; 2) the additional application of sinusoidal oscillations in the frequency range from 1 to 30 Hz; 3) subjection to the impulse in the kilohertz frequency range. The imposition of sinusoidal oscillations with the amplitude of 15% of the maximal load caused the reduction of time by 10% for the discussed in terms of durability. The high frequency impulse influence increased this effect and also caused essential changes in the amplitude of elastic oscillations generating during the stick-slip. The trigger phenomena should be integrated in prediction models of the time and magnitude of earthquakes.  相似文献   

Petrography and geochemistry of eclogites from the Mir kimberlite,Yakutia, Russia     

B. L. Beard  Kathy N. Fraracci  Robert A. Clayton  Toshiko K. Mayeda  G. A. Snyder  N. V. Sobolev  L. A. Taylor 《Contributions to Mineralogy and Petrology》1996,125(4):293-310

 Diamond-bearing eclogites are an important component of the xenoliths that occur in the Mir kimberlite, Siberian platform, Russia. We have studied 16 of these eclogite xenoliths, which are characterized by coarse-grained, equigranular garnet and omphacite. On the basis of compositional variations in garnet and clinopyroxene, this suite of eclogites can be divided into at least two groups: a high-Ca group and a low-Ca group. The high-Ca group consists of high-Ca garnets in equilibrium with pyroxenes that have high Ca-ratios [Ca/(Ca+Fe+Mg)] and high jadeite contents. These high-Ca group samples have high modal% garnet, and garnet grains often are zoned. Garnet patches along rims and along amphibole- and phlogopite-filled veins have higher Mg and lower Ca contents compared to homogeneous cores. The low-Ca group consists of eclogites with low-Ca garnets in equilibrium with pyroxenes with a low Ca-ratio, but variable jadeite contents. These low-Ca group samples typically have low modal% of garnet, and garnets are rarely compositionally zoned. Three samples have mineralogic compositions and modes transitional to the high- and low-Ca groups. We have arbitrarily designated these samples as the intermediate-Ca group. The rare-earth-element (REE) contents of garnet and clinopyroxene have been determined by ion microprobe. Garnets from the low-Ca group have low LREE contents and typically have [Dy/Yb]_n < 1. The high-Ca group garnets have higher LREE contents and typically have [Dy/Yb]_n > 1. Garnets from the intermediate-Ca group have REE contents between the high- and low-Ca groups. Clinopyroxenes from the low-Ca group have convex-upward REE patterns with relatively high REE contents (ten times chondrite), whereas those from the high-Ca group have similar convex-upward shapes, but lower REE contents, approximately chondritic. Reconstructed bulk-rock REE patterns for the low-Ca group eclogites are relatively flat at approximately ten times chondrite. In contrast, the high-Ca group samples typically have LREE-depleted patterns and lower REE contents. The δ¹⁸O values measured for garnet separates range from 7.2 to 3.1‰. Although there is a broad overlap of δ¹⁸O between the low-Ca and high-Ca groups, the low-Ca group samples range from mantle-like to high δ¹⁸O values (4.9 to 7.2‰), and the high-Ca group garnets range from mantle-like to low δ¹⁸O values (5.3 to 3.1‰). The oxygen isotopic compositions of two of the five high-Ca group samples and four of the eight low-Ca group eclogites are consistent with seawater alteration of basaltic crust, with the low-Ca group eclogites representative of low-temperature alteration, and the high-Ca group samples representative of high-temperature hydrothermal seawater alteration. We interpret the differences between the low- and high-Ca group samples to be primarily a result of differences in the protoliths of these samples. The high-Ca group eclogites are interpreted to have protoliths similar to the mid to lower sections of an ophiolite complex. This section of oceanic crust would be dominated by rocks which have a significant cumulate component and would have experienced high-temperature seawater alteration. Such cumulate rocks probably would be LREE-depleted, and can be Ca-rich because of plagioclase or clinopyroxene accumulation. The protoliths of the low-Ca group eclogites are interpreted to be the upper section of an ophiolite complex. This section of oceanic crust would consist mainly of extrusive basalts that would have been altered by seawater at low temperatures. These basaltic lavas would probably have relatively flat REE patterns, as seen for the low-Ca group eclogites. Received: 10 July 1995 / Accepted: 17 May 1996  相似文献   

The continuous spectra of supernovae in the period immediately after eruption     

A. K. Kolesov  V. V. Sobolev 《Astrophysics》1994,37(3):235-242

We consider the problem of the influence of electron scattering on the continuous spectrum of an envelope. For the radiation flux out of the envelope we assume an expression (1) obtained by us previously [3]. Computations using formula (1) are carried out for two models of the envelope: gray andpurely hydrogen. As a result we find the values of the following quantities, which characterize the continuous spectrum: the color indices U-B, B-V, V-R, and V-I; the Balmer jump D, and the bolometric correction BC. The values of these quantities are given in tables as functions of the surface temperature To of the envelope and the parameter /, where is the coefficient of electron scattering and is the mean absorption coefficient. We draw conclusions on the role of electron scattering for each model of the envelope.Translated fromAstrofizika, Vol. 37, No. 3, 1994.  相似文献   

Precursory seismicity changes associated with the  M_w= 7.4  1999 August 17 Izmit (Turkey) earthquake     

Q. Huang  A. O. Öncel  G. A. Sobolev 《Geophysical Journal International》2002,151(1):235-242

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Sm-Nd isotopic system in garnet megacrysts from the Udachnaya kimberlite pipe (Yakutia) and petrogenesis of kimberlites     

A. M. Agashev  N. P. Pokhilenko  V. G. Mal’kovets  Academician of the RAS N. V. Sobolev 《Doklady Earth Sciences》2006,407(2):491-494

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Theory of scattering photospheres     

V. V. Sobolev 《Astrophysics》1975,11(3):332-340

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Multiple scattering of radiation by free electrons in a homogeneous sphere     

Sobolev  V. V. 《Astrophysics》1974,10(2):113-116

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Color temperatures of objects with electron scattering     

V. V. Sobolev 《Astrophysics》1980,16(4):400-407

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Anisotropic scattering of light in an atmosphere of finite optical thickness     

V. V. Sobolev 《Astrophysics》1969,5(3):161-166

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