Early Paleozoic batholiths in the northern part of the Kuznetsk Alatau: Composition,age, and sources     

S. N. Rudnev  S. M. Borisov  G. A. Babin  O. A. Levchenkov  A. F. Makeev  P. A. Serov  D. I. Matukov  Yu. V. Plotkina 《Petrology》2008,16(4):395-419

The paper reports geological, chemical, and geochronological data on the Early Paleozoic granitoid and gabbro-granite associations, which compose the Kozhukhovskii and Dudetskii batholiths in the northern part of the Kuznetsk Alatau. The Kozhukhovskii batholith located in the Alatau volcanoplutonic belt is made up of tholeiitic, calc-alkaline, and subalkaline rocks that were formed in two stages. The first stage corresponded to the formation of granitoids of the Tylinskii quartz diorite-tonalite-plagiogranite complex (～530 Ma, Tylinskii Massif, tholeiitic type) in an island arc setting. The second stage (～500 Ma) produced the Martaiga quartz diorite-tonalite-plagiogranite complex (Kozhukhovskii Massif, calc-alkaline type) and the Krasnokamenskii monzodiorite-syenite-granosyenite complex (Krasnokamenskii Massif, subalkaline type) in an accretionary-collisional setting. The Dudetskii batholith is situated in the Altai-Kuznetsk volcanoplutonic belt and contains widespread subalkaline intrusive rocks (Malodudetskii monzogabbro-monzodiorite-syenite and Karnayul’skii granosyenite-leucogranite complexes) and less abundant alkaline rocks (Verkhnepetropavlovskii carbonatite-bearing alkaline-gabbroid complex), which were formed within the age range of 500–485 Ma. Our Nd isotopic studies suggest mainly a subduction source of the rocks of the Kozhukhovskii batholith (ε_Nd from + 4.8 to + 4.2). Subalkaline rocks of the Dudetskii batholith exhibit wide isotopic variations. The Nd isotopic composition of monzodiorites and monzogabbro of the Malodudetskii Complex (ε_Nd = + 6.6), in association with the elevated alkalinity and high Nb and Ta contents of these rocks, testifies to the predominant contribution of an enriched mantle source at the participation of a depleted mantle source. The lower ε_Nd (from + 3.2 to + 1.9) in its syenites possibly indicates their generation through melting of metabasic rocks derived from enriched mantle protolith. The rocks of the Karnayul’skii Complex have lower Nb and Ta contents at similar ε_Nd (+3.6), which suggests some crustal contribution to their formation.  相似文献   

PN G068.1+11.0: A young pre-cataclysmic variable with an extremely hot primary     

A. A. Mitrofanova  V. V. Shimansky  N. V. Borisov  O. I. Spiridonova  M. M. Gabdeev 《Astronomy Reports》2016,60(2):252-264

An analysis of spectroscopic and photometric data for the young pre-cataclysmic variable (PCV) PN G068.1+11.0, which passed through its common-envelope stage relatively recently, is presented. The spectroscopic and photometric data were obtained with the 6-m telescope and Zeiss-1000 telescope of the Special Astrophysical Observatory. The light curves show sinusoidal brightness variations with the orbital-period time scale and brightness-variation amplitudes of Δm = 1_.^m41, 1_.^m62, and 1_.^m57 in the B, V, and R bands, respectively. The system’s spectrum exhibits weak HI (Hβ–Hδ) andHeII λλ4541, 4686, 5411 Å absorption lines during the phases of minimum brightness, as well as HI, HeII, CIII, CIV, NIII, and OII emission lines whose intensity variations are synchronized with variations of the integrated brightness of the system. The emission-line formation in the spectra can be fully explained by the effects of fluorescence of the ultraviolet light from the primary at the surface of the cool star. All the characteristics of the optical light of PN G068.1+11.0 confirm that it is a young PCV containing sdO subdwarf. The radial velocities were measured from a blend of lines of moderately light elements, CIII+NIII λ4640 Å, which is formed at the surface of the secondary due to reflection effects. The ephemeris of the system has been improved through a joint analysis of the radial-velocity curves and light curves of pre-cataclysmic variable, using modelling of the reflection effects. The fundamental parameters of PN G068.1+11.0 have been determined using two evolutionary tracks for planetary-nebula nuclei of different masses (0.7 M_⊙and 0.78M_⊙). The model spectra for the system and a comparison with the observations demonstrate the possibility of refining the components’ effective temperatures if the quality of the spectra used is improved.  相似文献   

A quasi three-dimensional model for flow and transport in unsaturated and saturated zones: 1. Implementation of the quasi two-dimensional case     

A. Yakirevich  V. Borisov  S. Sorek 《Advances in water resources》1998,21(8):484

A quasi three-dimensional (QUASI 3-D) model is presented for simulating the subsurface water flow and solute transport in the unsaturated and in the saturated zones of soil. The model is based on the assumptions of vertical flow in the unsaturated zone and essentially horizontal groundwater flow. The 1-D Richards equation for the unsaturated zone is coupled at the phreatic surface with the 2-D flow equation for the saturated zone. The latter was obtained by averaging 3-D flow equation in the saturated zone over the aquifer thickness. Unlike the Boussinesq equation for a leaky-phreatic aquifer, the developed model does not contain a storage term with specific yield and a source term for natural replenishment. Instead it includes a water flux term at the phreatic surface through which the Richards equation is linked with the groundwater flow equation. The vertical water flux in the saturated zone is evaluated on the basis of the fluid mass balance equation while the horizontal fluxes, in that equation, are prescribed by Darcy law. A 3-D transport equation is used to simulate the solute migration. A numerical algorithm to solve the problem for the general quasi 3-D case was developed. The developed methodology was exemplified for the quasi 2-D cross-sectional case (QUASI2D). Simulations for three synthetic problems demonstrate good agreement between the results obtained by QUASI2D and two fully 2-D flow and transport codes (SUTRA and 2DSOIL). Yet, simulations with the QUASI2D code were several times faster than those by the SUTRA and the 2DSOIL codes.  相似文献   

Distribution of artificial radionuclides in the Black Sea and Mediterranean Sea in 1989–1990     

O. V. Stepanets  V. M. Komarevsky  A. P. Borisov  V. S. Karpov  T. V. Chudinovskikh  G. F. Batrakov  V. N. Eremeev 《Physical Oceanography》1993,4(5):417-423

The result of research into the distribution of artificial radionuclides of¹³⁷Cs in the Black Sea and the Mediterranean Sea are reported. The data obtained permits consideration of the peculiarities of distribution of this radionuclide in the areas under investigation. The contribution of the Chernobyl radiocaesium to the total radioactivity of these water areas is estimated.Translated by Mikhail M. Trufanov.  相似文献   

Geochemical technique of organic matter research in deposits enrich in kerogene (the Bazhenov Formation,West Siberia)     

E. V. Kozlova  N. P. Fadeeva  G. A. Kalmykov  N. S. Balushkina  N. V. Pronina  E. N. Poludetkina  O. V. Kostenko  A. Yu. Yurchenko  R. S. Borisov  A. Yu. Bychkov  A. G. Kalmykov  R. A. Khamidullin  E. D. Strel’tsov 《Moscow University Geology Bulletin》2015,70(6):409-418

The international interest in shale oil has recently provoked special attention to the Russian unconventional oil-source formations, including the Bazhenov Formation of West Siberia, domanik deposits in the Volga–Ural region, and the lower Maikop Group of the Cis-Caucasus. High contents of para-autochthonous soluble organic matter (bitumen) in clayey–carbonate, clayey–siliceous, carbonate–clayey–siliceous rocks with low filtration–capacity properties results in significant uncertainties in the identification of the generation potential of organic matter (OM). Examination of a large database on the OM of the Bazhenov Formation allowed us to propose an optimum complex technique for study of the source rock potential and assessment of the amount of produced hydrocarbons in the kerogen-rich sediments. The investigations include a combination of Rock Eval pyrolysis prior to and after extraction with different solvents, the comparison of bituminological and pyrolytic characteristics, and the determination of the group composition of soluble organic matter, as well as chromatography and chromato-mass spectrometry.  相似文献   

Determining the Characteristics of Lan 30 from Optical Observations     

Deminova  N. R.  Shimanskii  V. V.  Borisov  N. V.  Gabdeev  M. M. 《Astronomy Letters》2021,47(5):307-315

Astronomy Letters - We have performed a model analysis of the optical radiation from the young pre-cataclysmic variable Lan 30 and determined the set of its fundamental characteristics....  相似文献   

Discovery of the Most X-ray Luminous Quasar SRGE J170245.3+130104 at Redshift $$\boldsymbol{z\approx 5.5}$$     

Khorunzhev  G. A.  Meshcheryakov  A. V.  Medvedev  P. S.  Borisov  V. D.  Burenin  R. A.  Krivonos  R. A.  Uklein  R. I.  Shablovinskaya  E. S.  Afanasiev  V. L.  Dodonov  S. N.  Sunyaev  R. A.  Sazonov  S. Yu.  Gilfanov  M. R. 《Astronomy Letters》2021,47(3):123-140

Astronomy Letters - During the first all-sky survey of the SRG orbital observatory, the X-ray source SRGE J170245.3+130104 was discovered with the eROSITA telescope on March 13–15, 2020. Its...  相似文献   

Geological and Geophysical Investigation of Contourite Systems from the Central and Southern Atlantic during Cruise 52 of the R/V <Emphasis Type="Italic">Akademik Ioffe</Emphasis>     

E.?V.?IvanovaEmail author  I.?O.?Murdmaa  D.?G.?Borisov  N.?V.?Simagin  E.?A.?Ovsepyan  N.?V.?Libina  J.?I.?Isola  E.?V.?Bulycheva  N.?A.?Shulga  A.?V.?Krek  N.?V.?Lobus  L.?V.?Lapidus 《Oceanology》2018,58(2):322-324

  相似文献   

Spectroscopic Redshift Determination for a Sample of Distant Quasars Detected by the SRG Observatory Based on RTT-150 Observations. I     

Bikmaev  I. F.  Irtuganov  E. N.  Nikolaeva  E. A.  Sakhibullin  N. A.  Gumerov  R. I.  Sklyanov  A. S.  Glushkov  M. V.  Borisov  V. D.  Burenin  R. A.  Zaznobin  I. A.  Krivonos  R. A.  Lyapin  A. R.  Medvedev  P. S.  Meshcheryakov  A. V.  Sazonov  S. Yu.  Sunyaev  R. A.  Khorunzhev  G. A.  Gilfanov  M. R. 《Astronomy Letters》2020,46(10):645-657

Astronomy Letters - Results of the first spectroscopic observations at the 1.5-m Russian–Turkish telescope for the X-ray sources discovered by the eROSITA telescope onboard the SRG space...  相似文献   

On the formation of TW Crv optical radiation     

V. V. Shimansky  A. A. Mitrofanova  N. V. Borisov  S. N. Fabrika  A. I. Galeev 《Astrophysical Bulletin》2016,71(4):463-474

We present the analysis of the optical radiation of the young pre-cataclysmic variable TW Crv. Spectroscopic and photometric observations were obtained at the SAO RAS 6-m BTA telescope and at the Russian-Turkish RTT-150 telescope. The light curves of the system posses nearly sinusoidal shapes with the amplitudes of Δ_m > 0.^m7, what is typical for young pre-cataclysmic variables with sdO-subdwarfs and orbit inclinations of less than 45?. The optical spectrum contains dominant radiation of the hot subdwarf with the HI and He II absorption lines and strong emission lines, which are formed in the atmosphere of the secondary owing to the reflection effects. Radial velocities of the cool star were measured by analyzing the λλ 4630–4650 Å Bowen blend, which for the first time allowed to determine the component masses. A numerical simulation of the light curves and spectra of TW Crv, obtaining a complete set of systems fundamental parameters was carried out. The hot star parameters prompt its belonging to the sdOsubdwarf class at the stage of transition to the cooling white dwarf sequence. The absence of its observable planetary nebula is caused by a long-lasting evolution of the system after the common envelope state. The secondary component has a luminosity excess, which is typical for other young sdO-subdwarf precataclysmic variables. Its position on the “age??luminosity excess” diagram points at the accuracy of the obtained set of TW Crv fundamental parameters and at the similarity of its evolutionary and physical conditions with that of other BE UMa-type objects.  相似文献