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31.
The results of gasdynamic modeling allowed us to propose the new mechanism of transition to active state in classical symbiotics and explain the step-by-step rise to the light maximum during the outburst. Good agreement with available observational data for Z And supports our model. Existing observations of symbiotic stars indicate the presence of winds from both components at active stages in these systems. We have carried out the gasdynamic modeling of the outburst development process in the classic symbiotic star Z And in the framework of the colliding winds model. It is shown that contribution from the system of shocks that forms in the area of wind collision is rather significant especially at short wavelengths. 相似文献
32.
Victor G. Kornilov Vladimir M. Lipunov Evgeny S. Gorbovskoy Aleksander A. Belinski Dmitry A. Kuvshinov Natalia V. Tyurina Nikolai I. Shatsky Anatoly V. Sankovich Aleksander V. Krylov Pavel V. Balanutsa Vadim V. Chazov Artem S. Kuznetsov Dmitry S. Zimnuhov Victor A. Senik Andrey G. Tlatov Aleksander V. Parkhomenko Denis V. Dormidontov Vadim V. Krushinsky Ivan S. Zalozhnyh Aleksander A. Popov Sergey A. Yazev Nikolai M. Budnev Kirill I. Ivanov Evgeny N. Konstantinov Oleg A. Gress Oleg V. Chvalaev Vladimir V. Yurkov Yury P. Sergienko Irina P. Kudelina 《Experimental Astronomy》2012,33(1):173-196
Presented paper describes the basic principles and features of the implementation of a robotic network of optical telescopes MASTER, designed to study the prompt (simultaneous with gamma radiation) optical emission of gamma-ray bursts and to perform the sky survey to detect unknown objects and transient phenomena. With joint efforts of Sternberg astronomical institute, High altitude astronomical station of the Pulkovo observatory, Ural state university, Irkutsk state university, Blagoveshchensk pedagogical university, the robotic telescopes MASTER?II near Kislovodsk, Yekaterinburg, Irkutsk and Blagoveshchensk were installed and tested. The network spread over the longitudes is greater than 6?h. A further expansion of the network is considered. 相似文献
33.
Prognosis of TiO2 abundance in lunar soil using a non-linear analysis of Clementine and LSCC data 总被引:1,自引:0,他引:1
Viktor V. Korokhin Vadym G. Kaydash Dmitry G. Stankevich 《Planetary and Space Science》2008,56(8):1063-1078
We suggest a technique to determine the chemical and mineral composition of the lunar surface using artificial neural networks (ANNs). We demonstrate this powerful non-linear approach for prognosis of TiO2 abundance using Clementine UV-VIS mosaics and Lunar Soil Characterization Consortium data. The ANN technique allows one to study correlations between spectral characteristics of lunar soils and composition parameters without any restrictions on the character of these correlations. The advantage of this method in comparison with the traditional linear regression method and the Lucey et al. approaches is shown. The results obtained could be useful for the strategy of analyzing lunar data that will be acquired in incoming lunar missions especially in case of the Chandrayaan-1 and Lunar Reconnaissance Orbiter missions. 相似文献
34.
Shchukina Elena V. Agashev Aleksey M. Soloshenko Natalia G. Streletskaya Mariya V. Zedgenizov Dmitry A. 《Mineralogy and Petrology》2019,113(5):593-612
Mineralogy and Petrology - In this paper, new main and trace elements and isotopic data are presented for 14 coarse-grained eclogite xenoliths from the V. Grib kimberlite pipe in the central part... 相似文献
35.
Solar System Research - The article considers the problem of controlling the relative motion of spacecraft (SC) flying in tandem for interferometric imaging. The effect of the geometry of the... 相似文献
36.
Solar System Research - The article discusses the problems of controlling the relative motion of spacecraft (SC) in a tandem flight configuration. Flight configurations of two SC that form the... 相似文献
37.
Philipp R. Heck Christopher Herd Jeffrey N. Grossman Dmitry Badjukov Audrey Bouvier Emma Bullock Hasnaa Chennaoui‐Aoudjehane Vinciane Debaille Tasha L. Dunn Denton S. Ebel Ludovic Ferrire Laurence Garvie Jrme Gattacceca Matthieu Gounelle Richard Herd Trevor Ireland Emmanuel Jacquet Robert J. Macke Tim McCoy Francis M. McCubbin Takashi Mikouchi Knut Metzler Mathieu Roskosz Caroline Smith Meenakshi Wadhwa Linda Welzenbach‐Fries Toru Yada Akira Yamaguchi Ryan A. Zeigler Michael Zolensky 《Meteoritics & planetary science》2019,54(7):1397-1400
38.
Astrid Lyså Eiliv Larsen Jan‐Pieter Buylaert Ola Fredin Maria A. Jensen Denis Kuznetsov Andrew S. Murray Dmitry A. Subetto Aurelien van Welden 《Boreas: An International Journal of Quaternary Research》2014,43(4):759-779
The Late Pleistocene stratigraphy from the Severnaya Dvina‐Vychegda region of northwestern Russia is revised based on investigations of new localities, revisiting earlier localities, introduction of about 110 new OSL dates and burial depth corrections of earlier published OSL dates, in addition to six new radiocarbon dates. Most of the OSL samples studied here are from fluvial and subaquaeous sediments, which we found to be well bleached. Six chronostratigraphical units and their sedimentary environment are described, with the oldest unit consisting of pre‐Eemian glacial beds. For the first time, Early Weichselian sediments are documented from the region and a fluvial environment with some vegetation and permafrost conditions is suggested to have persisted from the end of the Eemian until at least about 92 ka ago. The period in which a Middle Weichselian White Sea Lake could have existed is constrained to 67?62 ka, but as the lake level never reached the thresholds of the drainage basin, the lake probably existed only for a short interval within this time‐span. Blocking and reversal of fluvial drainage started again around 21?20 ka ago when the Fennoscandian Ice Sheet advanced into the area, reaching its maximum 17?15 ka ago. At that time, an ice‐dammed lake reached its maximum water level, which was around 135 m above present sea level. Drainage of the lake started shortly after 15 ka ago, and the lake was emptied within 700 years. Severe periglacial conditions, with permafrost and aeolian activity, prevailed in the area until about 10.7 ka. 相似文献
39.
John Inge Svendsen Lars Martin B. Frseth Richard Gyllencreutz Haflidi Haflidason Mona Henriksen Morten N. Hovland
ystein S. Lohne Jan Mangerud Dmitry Nazarov Carl Regnll Joerg M. Schaefer 《Boreas: An International Journal of Quaternary Research》2019,48(2):407-431
Our knowledge about the glaciation history in the Russian Arctic has to a large extent been based on geomorphological mapping supplemented by studies of short stratigraphical sequences found in exposed sections. Here we present new geochronological data from the Polar Ural Mountains along with a high‐resolution sediment record from Bolshoye Shchuchye, the largest and deepest lake in the mountain range. Seismic profiles show that the lake contains a 160‐m‐thick sequence of unconsolidated lacustrine sediments. A well‐dated 24‐m‐long core from the southern end of the lake spans the last 24 cal. ka. From downward extrapolation of sedimentation rates we estimate that sedimentation started about 50–60 ka ago, most likely just after a large glacier had eroded older sediments from the basin. Terrestrial cosmogenic nuclide (TCN) exposure dating (10Be) of boulders and Optically Stimulated Luminescence (OSL) dating of sediments indicate that this part of the Ural Mountains was last covered by a coherent ice‐field complex during Marine Isotope Stage (MIS) 4. A regrowth of the glaciers took place during a late stage of MIS 3, but the central valleys remained ice free until the present. The presence of small‐ and medium‐sized glaciers during MIS 2 is reflected by a sequence of glacial varves and a high sedimentation rate in the lake basin and likewise from 10Be dating of glacial boulders. The maximum extent of the mountain glaciers during MIS 2 was attained prior to 24 cal. ka BP. Some small present‐day glaciers, which are now disappearing completely due to climate warming, were only slightly larger during the Last Glacial Maximum (LGM) as compared to AD 1953. A marked decrease in sedimentation rate around 18–17 cal. ka BP indicates that the glaciers then became smaller and probably disappeared altogether around 15–14 cal. ka BP. 相似文献
40.
Anne Claude Naki Akçar Susan Ivy-Ochs Fritz Schlunegger Philippe Rentzel Christine Pümpin Dmitry Tikhomirov Peter W. Kubik Christof Vockenhuber Andreas Dehnert Meinert Rahn Christian Schlüchter 《Swiss Journal of Geoscience》2017,110(3):793-809
The Quaternary stratigraphy of the Alpine Foreland consists of distinct terrace levels, which have been assigned to four morphostratigraphic units: Höhere (Higher) Deckenschotter, Tiefere (Lower) Deckenschotter, Hochterrasse (High Terrace) and Niederterrasse (Lower Terrace). Here, we focus on the terrace gravels at Hohle Gasse, SSE of Pratteln near Basel, which are mapped as Tiefere Deckenschotter. Petrographic and morphometric data established from clasts allowed to infer the transport mechanisms and sources of the gravels. Sedimentological analyses indicate that the gravels were transported by a braided river and deposited in a distal glaciofluvial setting. In addition, it can be shown that the majority of the clasts display multiple reworking and only a minority maintained a distinct glaciofluvial shape. Cosmogenic multi-isotope dating using 10Be and 36Cl allowed direct dating of the sediments at the study site. A depth-profile age of \(2 70_{ - 1 90}^{ + 8 30}\) ka for 10Be was achieved for the deposits at Hohle Gasse. Unfortunately, no age could be modelled from the 36Cl concentrations as the blank correction was too high. Furthermore, this age proves that the studied terrace level should be assigned to the morphostratigraphic unit Hochterrasse. 相似文献