Th-U-Pb dating of granite pegmatites from the Lipovskoe ore field (Urals) for three minerals     

V. V. Khiller  Yu. V. Erokhin  A. V. Zakharov  K. S. Ivanov 《Doklady Earth Sciences》2014,455(1):323-326

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Remote measurements of sound velocity variations in bottom sediments based on acoustic profiling data     

Yu. V. Gulyaev  A. I. Zakharov  V. I. Kaevitser 《Doklady Earth Sciences》2007,413(1):327-330

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Magnetic fields in active galactic nuclei and microquasars     

A. F. Zakharov  N. S. Kardashev  V. N. Lukash  S. V. Repin 《Monthly notices of the Royal Astronomical Society》2003,342(4):1325-1333

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Electrostatic charging and motion of dust near the surface of an asteroid   总被引：1，自引：0，他引：1  

N. D. Borisov  A. V. Zakharov 《Solar System Research》2014,48(1):22-32

The electrostatic charging and motion of dust near the surface of an asteroid is analyzed. It is shown that, despite the weak gravity, strong electric fields are needed to lift charged dust particles from the surface. The mechanism of generation of such fields, and the results of calculations of the motion of particles with various diameters in the electric fields near the dark side of the asteroid surface, is discussed. It is noted that the dust particle motion should be the most pronounced, as happens in the case of the Moon, in a certain neighborhood of the terminator.  相似文献   

Solar cycle according to mean magnetic field data   总被引：1，自引：0，他引：1  

V. N. Obridko  D. D. Sokoloff  K. M. Kuzanyan  B. D. Shelting  V. G. Zakharov 《Monthly notices of the Royal Astronomical Society》2006,365(3):827-832

To investigate the shape of the solar cycle, we have performed a wavelet analysis of the large–scale magnetic field data for 1960–2000 for several latitudinal belts and have isolated the following quasi-periodic components: ∼22, 7 and 2 yr. The main 22-yr oscillation dominates all latitudinal belts except the latitudes of ±30° from the equator. The butterfly diagram for the nominal 22-yr oscillation shows a standing dipole wave in the low-latitude domain  (∣θ∣≤ 30°)  and another wave in the sub-polar domain  (∣θ∣≥ 35°)  , which migrates slowly polewards. The phase shift between these waves is about π. The nominal 7-yr oscillation yields a butterfly diagram with two domains. In the low-latitude domain  (∣θ∣≤ 35°)  , the dipole wave propagates equatorwards and in the sub-polar region, polewards. The nominal 2-yr oscillation is much more chaotic than the other two modes; however the waves propagate polewards whenever they can be isolated.
We conclude that the shape of the solar cycle inferred from the large-scale magnetic field data differs significantly from that inferred from sunspot data. Obviously, the dynamo models for a solar cycle must be generalized to include large-scale magnetic field data. We believe that sunspot data give adequate information concerning the magnetic field configuration deep inside the convection zone (say, in overshoot later), while the large-scale magnetic field is strongly affected by meridional circulation in its upper layer. This interpretation suggests that the poloidal magnetic field is affected by the polewards meridional circulation, whose velocity is comparable with that of the dynamo wave in the overshoot layer. The 7- and 2-yr oscillations could be explained as a contribution of two sub-critical dynamo modes with the corresponding frequencies.  相似文献   

Analysis of optical light curves for the components of the gravitationally lensed quasar SBS 1520+530 based on observations with the 1.5-m RTT-150 telescope in 2001–2005     

I. M. Khamitov  I. F. Bikmaev  Z. Aslan  N. A. Sakhibullin  V. V. Vlasyuk  A. P. Zheleznyak  A. F. Zakharov 《Astronomy Letters》2006,32(8):514-519

We present the R _c-band light curves for components A and B of the gravitationally lensed quasar SBS 1520+530 obtained during 2001–2005 with the 1.5-m Russian-Turkish Telescope (RTT-150) at the TUBITAK National Observatory (Turkey). Based on an analysis of the data for the period 2001–2002, we have estimated the time delay of the brightness fluctuations between components A and B of the quasar to be 128 days. This time delay agrees with its previously published values for the periods 1999–2001 and 2003–2004. Using all of the published data on the brightnesses of components A and B of SBS 1520+530 for the 6-year period, we have found at least two microlensing events. One event has the pattern of a long-term linear trend; the duration of the other event is several hundred days.  相似文献   

Astrodynamical Space Test of Relativity using Optical Devices I (ASTROD I)—a class-M fundamental physics mission proposal for cosmic vision 2015–2025: 2010 Update     

Claus Braxmaier  Hansj?rg Dittus  Bernard Foulon  Ertan G?klü  Catia Grimani  Jian Guo  Sven Herrmann  Claus L?mmerzahl  Wei-Tou Ni  Achim Peters  Benny Rievers  étienne Samain  Hanns Selig  Diana Shaul  Drazen Svehla  Pierre Touboul  Gang Wang  An-Ming Wu  Alexander F. Zakharov 《Experimental Astronomy》2012,34(2):181-201

ASTROD I is a planned interplanetary space mission with multiple goals. The primary aims are: to test General Relativity with an improvement in sensitivity of over 3 orders of magnitude, improving our understanding of gravity and aiding the development of a new quantum gravity theory; to measure key solar system parameters with increased accuracy, advancing solar physics and our knowledge of the solar system; and to measure the time rate of change of the gravitational constant with an order of magnitude improvement and the anomalous Pioneer acceleration, thereby probing dark matter and dark energy gravitationally. It is envisaged as the first in a series of ASTROD missions. ASTROD I will consist of one spacecraft carrying a telescope, four lasers, two event timers and a clock. Two-way, two-wavelength laser pulse ranging will be used between the spacecraft in a solar orbit and deep space laser stations on Earth, to achieve the ASTROD I goals.For this mission, accurate pulse timing with an ultra-stable clock, and a drag-free spacecraft with reliable inertial sensor are required. T2L2 has demonstrated the required accurate pulse timing; rubidium clock on board Galileo has mostly demonstrated the required clock stability; the accelerometer on board GOCE has paved the way for achieving the reliable inertial sensor; the demonstration of LISA Pathfinder will provide an excellent platform for the implementation of the ASTROD I drag-free spacecraft. These European activities comprise the pillars for building up the mission and make the technologies needed ready. A second mission, ASTROD or ASTROD-GW (depending on the results of ASTROD I), is envisaged as a three-spacecraft mission which, in the case of ASTROD, would test General Relativity to one part per billion, enable detection of solar g-modes, measure the solar Lense-Thirring effect to 10 parts per million, and probe gravitational waves at frequencies below the LISA bandwidth, or in the case of ASTROD-GW, would be dedicated to probe gravitational waves at frequencies below the LISA bandwidth to 100?nHz and to detect solar g-mode oscillations. In the third phase (Super-ASTROD), larger orbits could be implemented to map the outer solar system and to probe primordial gravitational-waves at frequencies below the ASTROD bandwidth. This paper on ASTROD I is based on our 2010 proposal submitted for the ESA call for class-M mission proposals, and is a sequel and an update to our previous paper (Appouchaux et al., Exp Astron 23:491?C527, 2009; designated as Paper I) which was based on our last proposal submitted for the 2007 ESA call. In this paper, we present our orbit selection with one Venus swing-by together with orbit simulation. In Paper I, our orbit choice is with two Venus swing-bys. The present choice takes shorter time (about 250?days) to reach the opposite side of the Sun. We also present a preliminary design of the optical bench, and elaborate on the solar physics goals with the radiation monitor payload. We discuss telescope size, trade-offs of drag-free sensitivities, thermal issues and present an outlook.  相似文献   

Pixel lensing as a way to detect extrasolar planets in M31     

G. Ingrosso  S. Calchi Novati  F. De Paolis  Ph. Jetzer  A. A. Nucita  A. F. Zakharov 《Monthly notices of the Royal Astronomical Society》2009,399(1):219-228

We study the possibility to detect extrasolar planets in M31 through pixel-lensing observations. Using a Monte Carlo approach, we select the physical parameters of the binary lens system, a star hosting a planet, and we calculate the pixel-lensing light curve taking into account the finite source effects. Indeed, their inclusion is crucial since the sources in M31 microlensing events are mainly giant stars. Light curves with detectable planetary features are selected by looking for significant deviations from the corresponding Paczyński shapes. We find that the time-scale of planetary deviations in light curves increase (up to 3–4 d) as the source size increases. This means that only few exposures per day, depending also on the required accuracy, may be sufficient to reveal in the light curve a planetary companion. Although the mean planet mass for the selected events is about     , even small mass planets  ( M _P < 20 M_⊕)  can cause significant deviations, at least in the observations with large telescopes. However, even in the former case, the probability to find detectable planetary features in pixel-lensing light curves is at most a few per cent of the detectable events, and therefore many events have to be collected in order to detect an extrasolar planet in M31. Our analysis also supports the claim that the anomaly found in the candidate event PA-99-N2 towards M31 can be explained by a companion object orbiting the lens star.  相似文献   

The First All-Russia Meeting on “Jurassic of Russia: Problems of Stratigraphy and Paleogeography”     

V. A. Zakharov  B. N. Shurygin  O. S. Dzyuba  M. A. Rogov 《Stratigraphy and Geological Correlation》2006,14(3):341-343

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Significance of Caucasian Sections for Working out Carbon-Isotope Standard for Upper Permian and Lower Triassic （Induan） and Their Correlation with the Permian of North-Eastern Russia   总被引：1，自引：0，他引：1  

YuriDZakharov AlexanderSBiakov AymonBaud HeinzKozur 《中国地质大学学报(英文版)》2005,16(2):141-151

Data obtained on conodont distribution in the Permian-Triassic Sovetashen Section of Transcaucasia provide further limitations on the age of the carbon-isotopic anomalies discovered by Baud et al. (1989). The significance of Caucasian sections for working out the carbon-isotope standard for the Upper Permian and Lower Triassic (Induan) is shown. Original data on carbon-isotope composition of bivalve and brachiopod shells from Permian sediments of North-Eastern Russia (Omolon and Okhotsk areas) have been obtained, which may be used for their correlation.  相似文献