Biohorizons as infrazonal biostratigraphic units: An attempt to refine the Jurassic stratigraphy based on ammonites     

M. A. Rogov  D. B. Gulyaev  D. N. Kiselev 《Stratigraphy and Geological Correlation》2012,20(2):211-229

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Phase functions of polarization and brightness and the nature of cometary atmosphere particles     

N.N. Kiselev  G.P. Chernova 《Icarus》1981,48(3):473-481

The dependence of brightness and polarization of cometary on the phase angle is studied. The similarity between the phase curves of comets, minor planets, and the zodiacal cloud is pointed out. The dependence found correspond to dielectric particles with dimensions greater than 1 μm.  相似文献   

Results of astrometric observations of Jupiter’s Galilean satellites at the Pulkovo Observatory from 1986 to 2005     

T. P. Kiseleva  A. A. Kiselev  O. A. Kalinichenko  N. A. Vasilyeva  M. L. Khovricheva 《Solar System Research》2008,42(5):414-433

The results of photographic observations of Jupiter’s Galilean satellites made with the 26-inch refractor at the Pulkovo Observatory from 1986 to 2005 are given. Satellite coordinates with respect to Jupiter and the mutual distances between the satellites have been determined. A scale-trale technique that does not require reference stars for the astrometric reduction of measurements has been used. The effect of the Jupiter phase has been taken into account in the jovicentric coordinates. The observation results have been compared with a modern theory of the Galilean satellites’ motions. Systematic observation errors depending on the observation technique have been studied. The intrinsic observation accuracy in the random quotient is characterized by the values 0.041″ over X and Y. The external accuracy of the relative Galilean satellite coordinates determined by comparing the observations with modern ephemerides turned out to be equal to 0.165″, 0.213″ for the Jovicentric coordinates and 0.134″, 0.170″ for the “satellite-satellite” coordinates. The highest accuracy of the relative satellite coordinates is reached at small distances between the satellites which are less than 100″: the corresponding mean-square errors of one observation are equal in to the external convergence to 0.050″, 0.070″. The results of photographic observations have been compared with the first CCD observations of the Jupiter satellites made in 2004 with the 26-inch refractor.  相似文献   

西天山造山带构造单元划分及古生代洋陆转换过程   总被引：4，自引：2，他引：2       下载免费PDF全文

王宗秀  李春麟  Pak Nikolai  Ivleva Elen  余心起  周高  肖伟峰  韩淑琴  Halilov Zailabidin  Takenov Nurgazy  鄢犀利 《中国地质》2017,44(4):623-641

西天山造山带位于哈萨克斯坦—准噶尔板块与卡拉库姆—塔里木板块的结合部,是由一系列前寒武纪微陆块、古生代洋壳残片及陆缘弧相互拼贴而成的多聚合带、多成矿带,其独特的造山-成矿过程受到了国内外的广泛关注。本文通过构造单元划分与编图,建立了古生代西天山造山带的构造格架,认为古生代西天山造山带的构造演化依次经历了:罗迪尼亚大陆裂解与北天山早古生代多岛洋盆形成阶段(Z-O_2),北天山早古生代多岛洋盆闭合与南天山洋盆开始形成阶段(O_3-S),南、北天山洋晚古生代洋盆形成与发展阶段(D-C_1),南、北天山晚古生代洋盆全面闭合与天山碰撞造山带形成阶段(C1-C_2)和碰撞后板内演化阶段(C_2-P)。  相似文献   

Grid computing for atmospheric composition studies in Bulgaria     

Angelina Todorova  Dimiter Syrakov  Georgi Gadjhev  Georgi Georgiev  Kostadin G. Ganev  Maria Prodanova  Nikolai Miloshev  Valery Spiridonov  Andrej Bogatchev  Kiril Slavov 《Earth Science Informatics》2010,3(4):259-282

Three Grid applications from the SEE-GRID-SCI Environmental VO are developed by the Bulgarian project team: Climate Change Impact on Air Quality (CCIAQ); Multi-scale atmospheric composition modeling (MSACM); Modeling System for Emergency Response to the Release of Harmful Substances in the Atmosphere (MSERRHSA). The three applications concern problems of significant socio-economic significance. They are all dedicated to air pollution studies, but address different goals and so face different problems and requirements. The applications are briefly presented in the paper. Examples of the different applications validations are given. Some application results are shown and commented.  相似文献   

Short-term temporal variability of atmospheric surface pressure and wind speed in the Canadian Arctic     

Nikolai Nawri  Ronald E. Stewart 《Theoretical and Applied Climatology》2009,98(1-2):151-170

In this study, the spatial differences and interannual fluctuations in temporal variability of surface pressure and wind speed on different timescales at 12 locations in the Canadian Arctic are documented. Temporal variability is defined as the mean-squared value of time tendencies smoothed by running means over different intervals. It is shown that variability on timescales of up to 1 month is itself highly variable, both in space and time. Due to the significant impacts from the immediate geographical environment, for surface wind speed, these variations show no spatial pattern on a continental scale, and only a few persistent trends over periods of more than 10 years. Also, spatial and temporal anomalies do not significantly depend on timescale. Contrary to this, spatial and temporal variations in the variability of surface pressure and its changes with time show well-defined regional similarities, as well as a strong spatial and temporal dependence on timescale. As a result, variability of surface pressure on timescales between 1 and 3 days increases from the northeast region of the domain towards the southwest. On longer timescales, this spatial gradient is reversed. The consistent spatial pattern across the study domain suggests that variability of surface pressure is primarily governed by large-scale atmospheric processes, and is to a large extent independent of the exact geographical setting.  相似文献   

Determining the minimum sum of the component masses for a binary with a known parallax from observations of a short arc of its apparent motion     

A. A. Kiselev  O. V. Kiyaeva 《Astronomy Letters》2003,29(1):37-40

An inequality that allows the minimum sum of the component masses for a binary, M₀, to be determined was derived from simple geometric considerations. This quantity satisfies the observed orbital motion according to Newton's law with a known parallax. The M₀ value can be calculated if the apparent-motion parameters for the components, including the curvature of the observed short orbital arc, were determined from observations. We estimated M₀ for 14 Pulkovo program stars for which the apparent orbital arc covered with observations was no less than 10°. We compare M₀ with the masses estimated from the mass-luminosity relation. A significant mass excess was found for the star ADS 10329.  相似文献   

Comparing state-of the art near-surface models of a seismic test line from Saudi Arabia     

Ralph Bridle  Nikolai Barsoukov  Mohammad Al-Homaili  Robert Ley  Ameerah Al-Mustafa 《Geophysical Prospecting》2006,54(6):667-680

We present a seismic Test Line, provided by Saudi Aramco for various research teams, to highlight a few major challenges in land data processing due to near‐surface anomalies. We discuss state‐of‐the‐art methods used to compensate for shallow distortions, including single‐layer, multilayer, plus/minus, refraction and tomostatics methods. They are a starting point for the new technologies presented in other papers, all dealing with the same challenging data described here. The difficulties on the Test Line are mostly due to the assumption of vertical raypaths, inherent in classical applications of near‐surface correction statics. Even the most detailed velocity/depth model presents difficulties, due to the compleX‐raypath. There is a need for methods which are based on more complex models andtheories.  相似文献   

Crust and mantle of the Tien Shan from data of the receiver function tomography   总被引：2，自引：0，他引：2  

L. P. Vinnik  I. M. Aleshin  M. K. Kaban  S. G. Kiselev  G. L. Kosarev  S. I. Oreshin  Ch. Reigber 《Izvestiya Physics of the Solid Earth》2006,42(8):639-651

A 3-D velocity model of the Tien Shan crust and upper mantle is constructed through the inversion of the receiver functions of P and S waves together with teleseismic traveltime anomalies at nearly 40 local seismic stations. It is found that in the vast central region, where no strong earthquakes have been known over the past century, the S wave velocity at depths of 10–35 km is lower than in adjacent regions by up to 10%. These data are evidence for mechanical weakness of the crust preventing the accumulation of elastic energy. Apparently, the lower velocity and the weakness of the crust are due to the presence of water. The weakness of the crust is one of the possible reasons for the strain localization responsible for the formation of the present Tien Shan but can also be due in part to the young orogenesis. The crustal thickness is largest (about 60 km) in the Tarim-Tien Shan junction zone. The crust-mantle boundary in this region descends by a jump as a result of an increase in the lower crust thickness. This is probably due to the underthrusting of the Tien Shan by the Tarim lithosphere. This causes the mechanically weak lower crust of the Tarim to delaminate and accumulate in nearly the same way as an accretionary prism during the subduction of oceanic lithosphere. In the upper mantle, the analysis has revealed a low velocity anomaly, apparently related to basaltic outflows of the Upper Cretaceous-Early Paleogene. The Cenozoic Bachu uplift in the northern Tarim depression is also associated with the low velocity anomaly. The Naryn depression is characterized by a high velocity in the upper mantle and can be interpreted as a fragment of an ancient platform.  相似文献   

Metals in the river waters of Primorye     

V. M. Shulkin  N. N. Bogdanov  V. I. Kiselev 《Geochemistry International》2007,45(1):70-79

New data are presented on the contents of Fe, Mn, Zn, Cu, Pb, Cd, and Ni in dissolved and particulate modes of occurrence in unpolluted or anthropogenically contaminated major rivers of Primorye. The background contents of dissolved metals are as follows: 0.1–0.5 μg/l for Zn and Ni, 0.3–0.7 μg/l for Cu, 0.01–0.04 μg/l for Pb and Cd, and 2–20 μg/l for Fe and Mn. Common anthropogenic loading (communal wastewaters) notably increases the dissolved Fe and Mn concentrations Industrial wastes lead to a local increase in the contents of dissolved metals in river waters by one to three orders of magnitude. The effect of hydrological regime is expressed most clearly in the areas of anthropogenic impact. The metal contents in the particulate matter are controlled mainly by its granulometric composition. Original Russian Text ? V.M. Shulkin, N.N. Bogdanov, V.I. Kiselev, 2007, published in Geokhimiya, 2007, No. 1, pp. 79–88.  相似文献