The Investigation of Optical Variability on Time Scales of 10-7-102S: Hardware, Software, Results     

G.M. Beskin  V.N. Komarova  S.I. Neizvestny  V.L. Plokhotnichenko  M.Yu. Popova  A.V. Zhuravkov 《Experimental Astronomy》1997,7(4):413-420

We present a hardware/software complex for photometric observations with high time resolution. The hardware consists of a detector, a recording system which is a "time - coded" converter, a PC/AT 486 computer and a tape recorder. As a detector we can use any device that provides its output in such a way that for every detected quantum there is a correspondent standard impulse with additional information on the quantum - space coordinates, frequency, polarization, etc. A special "time - coded" converter "Quantochron" registers the quanta arrival times with an accuracy of ± 20 nanoseconds stores in the computer the 16-bit codes as well as the 16-bit codes of additional information. At present, the photometer complex allows to register without distortion the flux events up to 380 kHz. We describe the special methods and software capable of searching and analyzing any type of photon flux intensity variations. The results of the high time resolution investigations of a number of relativistic and fast variable objects, such as black hole candidates, LMXB, pulsars and flare stars, are presented.  相似文献   

Behavior of lanthanides during the formation of the Svetloe deposit,Chukotka     

Yu. A. Popova  A. Yu. Bychkov  S. S. Matveeva 《Geochemistry International》2016,54(8):732-738

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New Pb-As-Bearing eulytite from the Galechnoe deposit, Eastern Yakutia     

G. N. Gamyanin  N. S. Bortnikov  Yu. Ya. Zhdanov  N. V. Zayakina  A. V. Mokhov  S. K. Popova  V. S. Suknev 《Doklady Earth Sciences》2007,413(2):300-303

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Systematics of rare earth elements, Th, Hf, Sc, Co, Cr, and Ni in the vendian pelitic rocks of the Serebryanka and Sylvitsa groups from the western slope of the Central Urals: A tool for monitoring provenance composition     

A. V. Maslov  Yu. L. Ronkin  M. T. Krupenin  G. A. Petrov  A. Yu. Kornilova  O. P. Lepikhina  O. Yu. Popova 《Geochemistry International》2006,44(6):559-580

This paper presents the first data on the systematics of rare earth elements (REE), Th, Hf, Sc, Co, Cr, and Ni and the Nd model ages of fine-grained aluminosilicate clastic rocks of the Serebryanka and Sylvitsa groups of the Vendian from the Kvarkushsko-Kamennogorskii meganticlinorium (western slope of the Central Urals). It was found that the REE distribution patterns of shales and mudstones of the two groups are similar to those of the majority of post-Archean fine-grained terrigenous complexes. The presence of pelitic rocks with Gd_N/Yb_N > 2.0 in a number of Vendian levels suggests a contribution from an Archean component in the composition of the fine aluminosilicate clastic material. This is probably also indicated by the high degree of heavy REE depletion in some mudstone samples. The REE systematics allow us to suppose a heterogeneity of Vendian paleocatchments and variations in their composition with time. The eroded areas had the most mature composition in the beginning of Serebryanka. Starting from the second half of Serebryanka, mafic and/or ultramafic rocks started playing a significant role in the provenances. The rocks of the lower portion of the Serebryanka Group show T_Nd(DM) values of about 2.0 Ga, whereas the upper part of the section is dominated by rocks with T_Nd(DM) ? 1.77–1.73 Ga. This indicates that during the Taninskaya and Koiva time periods, fine aluminosilicate clastic material was supplied into the sedimentation region mainly from the west, from the eastern areas of the east European platform, where Archean and Early Proterozoic crystalline complexes dominated. A decrease in model ages was related to the addition of juvenile mantle material to the mature continental crust. Such processes can be illustrated by the mafic-ultramafic complexes (Dvoretskii, Shpalorezovskii, Vil’vinskii, etc.) located in the field of Vendian sedimentary sequences, which show T_Nd(DM) values from 824 to 707 Ma. It was concluded that the history of the formation of an Early Vendian rift in the western slope of the central Urals included only one rifting event (rather than three, as was previously supposed), which was supported by a variety of recent geological and isotope geochemical data.  相似文献   

The crystal structure of loparite: a new acentric variety     

Popova  Elena A.  Lushnikov  Sergey G.  Yakovenchuk  Victor N.  Krivovichev  Sergey V. 《Mineralogy and Petrology》2017,111(6):827-832

Mineralogy and Petrology - The crystal structure of a new structural variety of loparite (Na0.56Ce0.21La0.14Ca0.06Sr0.03Nd0.02Pr0.01)Σ=1.03(Ti0.83Nb0.15)Σ=0.98O3 from the Khibiny alkaline...  相似文献   

Relation between sudden increases in the solar wind dynamic pressure,auroral proton flashes,and geomagnetic pulsations in the Pc1 range     

T. A. Popova  A. G. Yahnin  T. A. Yahnina  H. Frey 《Geomagnetism and Aeronomy》2010,50(5):568-575

The interrelation between sudden increases in the solar wind dynamic pressure, auroral proton flashes on the dayside equatorward of the oval, and geomagnetic pulsations in the Pc1 range is considered on the basis of simultaneous observations of the solar wind plasma parameters, proton auroras on the IMAGE satellite, and geomagnetic pulsations at the Lovozero Observatory. It is indicated that proton luminosity flashes were observed in 70% of cases equatorward of the auroral oval during sudden changes in the solar wind pressure. In this case, flashes of proton auroras were observed in 85% of cases during sudden changes in the pressure, which were related to interplanetary shocks. Increases in pressure during tangential discontinuities were accompanied by flashes of proton auroras only in 45% of cases. When the ground station was conjugate to the region occupied by a proton aurora flash, the appearance or intensification of existent pulsations in the Pc1 range was observed in 96% of cases. When the ground station was not conjugate to the region of a proton luminosity flash, the response in geomagnetic pulsations was observed in 32% of events. When a sudden change in the solar wind pressure was not accompanied by a proton luminosity flash, the response in pulsations in the Pc1 range was hardly observed.  相似文献   

Simulating pathways of subsurface oil in the Faroe–Shetland Channel using an ocean general circulation model     

C.E. Main  A. Yool  N.P. Holliday  E.E. Popova  D.O.B. Jones  H.A. Ruhl 《Marine pollution bulletin》2017,114(1):315-326

Little is known about the fate of subsurface hydrocarbon plumes from deep-sea oil well blowouts and their effects on processes and communities. As deepwater drilling expands in the Faroe–Shetland Channel (FSC), oil well blowouts are a possibility, and the unusual ocean circulation of this region presents challenges to understanding possible subsurface oil pathways in the event of a spill. Here, an ocean general circulation model was used with a particle tracking algorithm to assess temporal variability of the oil-plume distribution from a deep-sea oil well blowout in the FSC. The drift of particles was first tracked for one year following release. Then, ambient model temperatures were used to simulate temperature-mediated biodegradation, truncating the trajectories of particles accordingly. Release depth of the modeled subsurface plumes affected both their direction of transport and distance travelled from their release location, and there was considerable interannual variability in transport.  相似文献   

Circumbinary Planetary Systems in the Solar Neighborhood: Stability and Habitability     

Shevchenko  I. I.  Melnikov  A. V.  Popova  E. A.  Bobylev  V. V.  Karelin  G. M. 《Astronomy Letters》2019,45(9):620-626

Astronomy Letters - The radii of the inner and outer boundaries of the circumbinary habitable zone (CBHZ) and the radii of the circumbinary chaotic zone (CBCZ) have been calculated for close binary...  相似文献   

Asteroid Apophis: Evaluating the impact hazards of such bodies     

V. V. Shuvalov  V. V. Svettsov  N. A. Artem’eva  I. A. Trubetskaya  O. P. Popova  D. O. Glazachev 《Solar System Research》2017,51(1):44-58

Soon after the discovery of asteroid 99942 Apophis, it was classified as a potentially hazardous object with a high probability of an impact on the Earth in 2029. Although subsequent observations have substantially reduced the probability of a collision, it has not been ruled out; moreover, similar-sized asteroids in orbits intersecting the Earth’s orbit may well be discovered in the near future. We conduct a numerical simulation of an atmospheric passage and an impact on the Earth’s surface of a stony cosmic body with a diameter of 300 m and kinetic energy of about 1000 Mt, which roughly corresponds to the parameters of the asteroid Apophis, at atmospheric entry angles of 90° (vertical stroke), 45°, and 30°. The simulation is performed by solving three-dimensional equations of hydrodynamics and radiative transfer equations in the approximations of radiative heat conduction and volume emission. The following hazards are considered: an air shock wave, ejecta from the crater, thermal radiation, and ionospheric disturbances. Our calculations of the overpressure and wind speed on the Earth’s surface show that the zone of destruction of the weakest structures can be as large as 700–1000 km in diameter; a decrease in the flight path angle to the surface leads to a marked increase in the area affected by the shock wave. The ionospheric disturbances are global in nature and continue for hours: at distances of several thousand kilometers at altitudes of more than 100 km, air density disturbances are tens of percent and the vertical and horizontal velocity components reach hundreds of meters per second. The impact of radiation on objects on the Earth’s surface is estimated by solving the equation of radiative transfer along rays passing through a luminous area. In clear weather, the size of the zone where thermal heating may ignite wood can be as large as 200 km, and the zone of individual fire outbreaks associated with the ignition of flammable materials can be twice as large. In the 100-km central area, which is characterized by very strong thermal damage, there is ignition of structures, roofs, clothes, etc. The human hazardous area increases with the decrease in the trajectory angle, and people may experience thermal effects at distances of up to 250–400 km from the crater.  相似文献   

Binaries in the vicinity of the open cluster IC 4665.I. V 378 Oph     

Z. Kraicheva  M. Popova  A. Antov 《Astronomische Nachrichten》1989,310(3):227-230

Erste Ergebnisse unseres Programms zur Untersuchung von Doppelsternen, die mögliche Mitglieder von offenen Sternhaufen sind, werden vorgestellt. Daneben wurde die Verteilung von spektroskopischen Variablen und Bedeckungsveränderlichen in der weiteren Umgebung des offenen Haufens IC 4665 ermittelt. Desweiteren wird über eine photometrische Studie des Variablen V 378 Oph berichtet. Über dieses Objekt gibt es, den Helligkeitswechsel betreffend, widersprüchliche Daten. Unsere Beobachtungen bestätigen, daß V 378 Oph ein Doppelstern vom Typ ß Lyrae ist. Seine Periode wurde bestimmt und eine mittlere Lichtkurve ermittelt. Es wird auf einige Besonderheiten hingewiesen, die zusätzliche lichtelektrische und photometrische Beobachtungen erfordern. Anschließend wird diskutiert, ob V 378 Oph zu Mel 186 (Cr 359) oder IC 4665 gehört.  相似文献