Millennial-scale climatic and environmental oscillations in the Sea of Okhotsk in response to global changes during the last 190 Ka     

S. A. Gorbarenko  N. Harada  M. I. Malakhov  Yu. P. Vasilenko  A. A. Bosin  E. L. Gol’dberg 《Doklady Earth Sciences》2008,423(2):1410-1413

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Disseminated ores of the Darasun gold deposit (Eastern Transbaikalia) and their genesis     

V. Yu. Prokof’ev  N. S. Bortnikov  A. V. Volkov  I. A. Baksheev  L. D. Zorina 《Doklady Earth Sciences》2008,422(1):1025-1027

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Dependence of the water content in channels of the cordierite structure on the composition of its Fe-Mg solid solutions     

T. A. Bul’bak  S. V. Shvedenkova 《Doklady Earth Sciences》2008,419(2):477-480

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The structure of the tectonosphere of the Urals and West Siberian Platform by electromagnetic data     

A. G. D’yakonova  K. S. Ivanov  O. V. Surina  P. F. Astaf’ev  V. S. Vishnev  A. D. Konoplin 《Doklady Earth Sciences》2008,423(2):1479-1482

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Different magneto-rotational supernovae     

G. S. Bisnovatyi-Kogan  S. G. Moiseenko  N. V. Ardelyan 《Astronomy Reports》2008,52(12):997-1008

We present the results of two-dimensional calculations of a magneto-rotational (MR) supernova explosion with a collapsing core for various core masses, rotational angular momenta, and magnetic-field configurations. It is shown that the MR mechanism produces an explosion energy that corresponds to observed values. The form of the explosion depends substantially on the initial configuration of the magnetic field. MR instability develops during the evolution of the magnetic field in an MR supernova explosion, resulting in an exponential increase of all components of the magnetic field, thereby substantially decreasing the time scale of the MR explosion. The energy of the supernova increases with the core’s mass and initial rotational energy.  相似文献   

Scheme of mineral facies of metamorphic rocks     

S. A. Bushmin  V. A. Glebovitsky 《Geology of Ore Deposits》2008,50(8):659-669

The proposed PT grid of mineral facies of metamorphic rocks, which retains the commonly adopted nomenclature (greenschist, epidote-amphibolite, amphibolite, granulite, glaucophane-schist, and eclogite facies), is based on original calculations and the published calculated and experimental data on mineral equilibria. To validate the facies and subfacies PT boundaries, the mineral equilibria in metapelitic and metabasic rocks have been used.  相似文献   

Rare earth elements in tourmaline and chlorite from tin-bearing assemblages: Factors controlling fractionation of REE in hydrothermal systems     

N. S. Bortnikov  N. V. Gorelikova  P. G. Korostelev  V. G. Gonevchuk 《Geology of Ore Deposits》2008,50(6):445-461

The REE distribution in minerals from tin-bearing ore-magmatic systems of the Russian Far East, including the Komsomolsk, Khingan, and Badzhal districts in the Amur region and the Kavalerovo, Lesozavodsk, Voznesenka, Furmanovo, and other districts in Primorsky krai, has been studied. The main attention was focused on tourmaline and chlorite; in addition, associated biotite, feldspar, apatite, fluorite, and carbonates were examined. The major factors affecting the REE distribution in the studied minerals are the temperature, Eh, and pH of the mineral-forming medium; crystal chemistry; partition coefficients of REE between fluid and minerals; and complexation that disturbs the coherent behavior of REE. Fluid evolution at different stages is characterized.  相似文献   

The Seyfert 1 galaxy Ark 120. Spectral variability in 1992–2005     

V. T. Doroshenko  S. G. Sergeev  V. I. Pronik 《Astronomy Reports》2008,52(6):442-462

We have studied the variability of the Hβ line and the adjacent continuum in the spectrum of the Seyfert galaxy Ark 120, based on spectral observations of the galaxy’s nucleus obtained in the Crimea in 1992–2005, supplemented by published data for 1988–1996. Irregular variability on various timescales (years to days) can be accompanied by periodic brightness variations in both the continuum and the Hβ line, with a period of P ～ 430 days and an amplitude of Δm ～ 0.2 ^m in the continuum, which were traced for more than 13 cycles. In total, in 1988–2005, the flux variations in the line lag those in the continuum by 55 ± 9 days if calculated from the peak of the cross correlation function, or by 72 ± 7 days, if calculated from the centroid of the CCF. The delay is correlated with the continuum brightness, increasing when the continuum flux increases. The Hβ line profiles indicate both a high degree of diversity and the presence of features that recur after various extended time intervals. Analysis of the evolution of the differences between each individual normalized line profile and the mean normalized profile indicates systematic motion of excesses relative to the average profile from negative to positive radial velocities. In contrast, parts of the Hβ line with low radiation relative to the mean normalized profile evolve in the opposite direction (from the red to the blue Hβ wing). This pattern is also typical for the rotating broad-line region, if this region has the form of a disk. The rotation period exceeds 9000–10000 days, or 25–27 years. The size of the broad-line region calculated form this period corresponds to a reverberation time of no fewer than 30 days, consistent with the results of cross-correlation analysis.  相似文献   

Surface complexation modeling of Cu(II) adsorption on mixtures of hydrous ferric oxide and kaolinite     

Tracy J Lund  Carla M Koretsky  Christopher J Landry  Melinda S Schaller  Soumya Das 《Geochemical transactions》2008,9(1):9

Background  

The application of surface complexation models (SCMs) to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids.  相似文献   

Crystal chemistry of selenates with mineral-like structures: V. Crystal structures of (H3O)2[(UO2)(SeO4)2(H2O)](H2O)2 and (H3O)2[(UO2)(SeO4)2(H2O)](H2O), new compounds with rhomboclase and goldichite topology     

S. V. Krivovichev 《Geology of Ore Deposits》2008,50(8):789-794

The crystal structures of two new compounds (H₃O)₂[(UO₂)(SeO₄)₂(H₂O)](H₂O)₂ (1, orthorhombic, Pnma, a = 14.0328(18), b = 11.6412(13), c = 8.2146(13) Å, V = 134.9(3) ų) and (H₃O)₂[(UO₂)(SeO₄)₂(H₂O)](H₂O) (2, monoclinic, P2₁/c, a = 7.8670(12), b = 7.5357(7), c = 21.386(3) Å, β = 101.484(12)°, V = 1242.5(3) ų) have been solved by direct methods and refined to R ₁ = 0.076 and 0.080, respectively. The structures of both compounds contain sheet complexes [(UO₂)(SeO₄)₂]^2? formed by cornershared [(UO₂)O₄(H₂O)] bipyramids and SeO₄ tetrahedrons. The sheets are parallel to the (100) plane in structure 1 and to (?102) in structure 2. The [(UO₂)(SeO₄)₂(H₂O)]^2? layers are linked by hydrogen bonds via interlayer groups H₂O and H₃O⁺. The sheet topologies in structures 1 and 2 are different and correspond to the topologies of octahedral and tetrahedral complexes in rhomboclase (H₂O₂)⁺[Fe(SO₄)₂(H₂O)₂] and goldichite K[Fe(SO₄)₂(H₂O)₂](H₂O)₂, respectively.  相似文献