全文获取类型
收费全文 | 473篇 |
免费 | 0篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 8篇 |
地球物理 | 47篇 |
地质学 | 282篇 |
海洋学 | 31篇 |
天文学 | 103篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 17篇 |
2019年 | 19篇 |
2018年 | 37篇 |
2017年 | 31篇 |
2016年 | 18篇 |
2015年 | 6篇 |
2014年 | 19篇 |
2013年 | 26篇 |
2012年 | 26篇 |
2011年 | 31篇 |
2010年 | 15篇 |
2009年 | 23篇 |
2008年 | 23篇 |
2007年 | 32篇 |
2006年 | 43篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有473条查询结果,搜索用时 78 毫秒
61.
Lipunov V. M. Vladimirov V. V. Gorbovskoi E. S. Kuznetsov A. S. Zimnukhov D. S. Balanutsa P. V. Kornilov V. G. Tyurina N. V. Gress O. A. Vlasenko D. M. Gabovich A. M. Yurkov V. V. Kuvshinov D. A. Senik V. A. 《Astronomy Reports》2019,63(4):293-309
Astronomy Reports - The concept of a multi-functional astronomical complex as applied to robotic astronomy networks and systems is formulated. The practical realization of this concept in the... 相似文献
62.
Doklady Earth Sciences - Temperature relations of β-factors for 18O/16O fractionations in TiO2 polymorphs have been determined using the density functional theory:... 相似文献
63.
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
64.
Lithology and Mineral Resources - Distribution of carbonate sediments of different composition in the Precambrian section is reviewed. It is shown that calcium carbonates prevailed in the... 相似文献
65.
Razumovskiy A. A. Novikov I. A. Ryazantsev A. V. Rud’ko S. V. Kuznetsov N. B. Yashunskiy Yu. V. 《Doklady Earth Sciences》2020,495(2):867-871
Doklady Earth Sciences - U–Th–Pb (SHRIMP II) isotopic dating of accessory zircons from Vendian (Ediacaran) ash tuffs of the Basa formation section (Asha Group, Southern Ural) was... 相似文献
66.
Doklady Earth Sciences - A new technique for the complete dissolution of cassiterite, which makes it possible to determine the age of this mineral by U–Pb isotope dilution (ID-TIMS), has been... 相似文献
67.
Golionko B. G. Ryazantsev A. V. Degtyarev K. E. Kanygina N. A. Kuznetsov N. B. Sheshukov V. S. Dubensky A. S. Gareev B. I. 《Doklady Earth Sciences》2020,493(2):578-583
Doklady Earth Sciences - The first U–Pb (LA–ICP–MS) isotope dating of detrital zircons from quartzites of two strata of the Maksyutov metamorphic complex (Southern Urals) was... 相似文献
68.
The South Ural meteoroid (February 15, 2013; near the city of Chelyabinsk) is undoubtedly the best documented meteoroid in history. Its passage through the atmosphere has been recorded on videos and photographs, visually by observers, with ground-based infrasound microphones and seismographs, and by satellites in orbit. In this work, the results are presented of an analysis of the transionospheric GPS sounding data collected in the vicinity of the South Ural meteoroid site, which show a weak ionospheric effect. The ionospheric disturbances are found to be asymmetric about the explosion epicenter. The received signals are compared, both in shape and amplitude, with the reported ionospheric effects of ground level explosions with radio diagnostics. It is shown that the confident registration of ionospheric effects as acoustic gravity waves (AGWs) by means of vertical sounding and GPS technologies for ground explosions in the range of 0.26–0.6 kt casts doubt on the existing TNT equivalent estimates (up to 500 kt) for the Chelyabinsk event. The absence of effects in the magnetic field and in the ionosphere far zone at distances of 1500–2000 km from the superbolide explosion epicenter also raises a question about the possibility of an overestimated TNT equivalent. An alternative explanation is to consider the superposition of a cylindrical ballistic wave (due to the hypersonic motion of the meteoroid) with spherical shock waves caused by the multiple time points of fragmentation (multiple explosions) of the superbolide as a resulting source of the AGW impact on ionospheric layers. 相似文献
69.
The data given are the results of many-year studying the distribution of the concentrations of main oil components (hydrocarbons, surfactants, and asphaltene-tarry substances) in the water mass, vertically settling particulate matter, and bottom sediment cores taken from the section Lower Don-The Gulf of Taganrog-Russian sector of the Sea of Azov in summer and autumn periods in 2006–2011. Spatial and seasonal regularities in the distributions of the total concentration of oil components and the values of their ratios in water, as well as the spatial and annual features of their accumulation in bottom sediments have been established. Radiological methods have been used for layer-by-layer dating of bottom sediment cores and determine the thickness of the layer that had formed under the maximal anthropogenic impact on ecosystems. The presence of considerable amounts of hydrocarbons of modern biological origin has been revealed in all components of examined aquatic complexes. 相似文献
70.
E. D. Kuznetsov 《Solar System Research》2011,45(5):433-446
The effect of the radiation pressure and Poynting-Robertson effect on the evolution of the orbits of geosynchronous satellites
is studied, depending on their area to mass ratio. The qualitative changes of the orbital evolution caused by these disturbances
are considered. The reflection coefficient of the satellite’s surface was assumed to be 1.44. In the vicinity of the stable
point with the longitude of 75° the exit from the libration resonance mode was registered when the area to mass ratio value
changed from 5.9 to 6.0 m2/kg; in the vicinity of the unstable point at 345° with the area to mass ratio of 1.4 it occurred at 1.5 m2/kg. Re-entry to Earth occurs at values of the area to mass ratio above 32.2 m2/kg, and hyperbolic exit from the low-Earth orbit occurs at values of the area to mass ratio over 5267 m2/kg. At high values of the area to mass ratio, slopes of initially equatorial orbits can reach 49°. It is shown that due to
the Poynting-Robertson effect the secular decrease in the semimajor axis of orbit in libration resonance region is 3–4 orders
of magnitude less than outside of it. 相似文献