全文获取类型
收费全文 | 432篇 |
免费 | 16篇 |
国内免费 | 21篇 |
专业分类
测绘学 | 12篇 |
大气科学 | 25篇 |
地球物理 | 132篇 |
地质学 | 155篇 |
海洋学 | 25篇 |
天文学 | 89篇 |
综合类 | 10篇 |
自然地理 | 21篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 31篇 |
2017年 | 22篇 |
2016年 | 22篇 |
2015年 | 32篇 |
2014年 | 24篇 |
2013年 | 36篇 |
2012年 | 30篇 |
2011年 | 35篇 |
2010年 | 25篇 |
2009年 | 22篇 |
2008年 | 23篇 |
2007年 | 29篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 14篇 |
2003年 | 5篇 |
2002年 | 16篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有469条查询结果,搜索用时 31 毫秒
291.
Sergey M. Kudryavtsev 《Celestial Mechanics and Dynamical Astronomy》2008,101(4):337-348
The aim of this study is to obtain high-accurate harmonic developments of the tide-generating potential (TGP) of Mercury,
Venus and Mars. The planets’ TGP values have been first calculated on the base of DE/LE-406 numerical planetary/lunar ephemerides
over a long period of time and then processed by a new spectral analysis method. According to this method the development
is directly made to Poisson series where both amplitudes and arguments of the series’ terms are high-degree polynomials of
time. A new harmonic development of Mars TGP is made over the time period 1900 AD–2100 AD and includes 767 second-order Poisson
series’ terms of minimum amplitude equal to 10−7 m2 s−2. Analogous series composing both Mercury and Venus TGP harmonic models are built over the time period 1000 AD–3000 AD and
include 1,061 and 693 terms, respectively. A modification of the standard HW95 format for representation of the terrestrial
planets’ TGP is proposed. The number of terms in the planets’ TGP models transformed to the modified HW95 format is 650 for
Mercury, 422 for Venus, and 480 for Mars. The quality of the new developments of the terrestrial planets’ TGP is better than
that of the similar developments obtained earlier.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
292.
293.
294.
A New Tool for Inundation Modeling: Community Modeling Interface for Tsunamis (ComMIT) 总被引:2,自引:0,他引:2
V. V. Titov C. W. Moore D. J. M. Greenslade C. Pattiaratchi R. Badal C. E. Synolakis U. Kânoğlu 《Pure and Applied Geophysics》2011,168(11):2121-2131
Almost 5 years after the 26 December 2004 Indian Ocean tragedy, the 10 August 2009 Andaman tsunami demonstrated that accurate
forecasting is possible using the tsunami community modeling tool Community Model Interface for Tsunamis (ComMIT). ComMIT
is designed for ease of use, and allows dissemination of results to the community while addressing concerns associated with
proprietary issues of bathymetry and topography. It uses initial conditions from a precomputed propagation database, has an
easy-to-interpret graphical interface, and requires only portable hardware. ComMIT was initially developed for Indian Ocean
countries with support from the United Nations Educational, Scientific, and Cultural Organization (UNESCO), the United States
Agency for International Development (USAID), and the National Oceanic and Atmospheric Administration (NOAA). To date, more
than 60 scientists from 17 countries in the Indian Ocean have been trained and are using it in operational inundation mapping. 相似文献
295.
On 15 July 2009, a Mw 7.8 earthquake occurred off the New Zealand coast, which by serendipitous coincidence occurred while
the International Tsunami Symposium was in session in Novosibirsk, Russia. The earthquake generated a tsunami that propagated
across the Tasman Sea and was detected in New Zealand, Australia and as far away as the US West coast. Small boats close to
the epicenter were placed in jeopardy, but no significant damage was observed despite a measured run-up height of 2.3 m in
one of the Sounds in close proximity to the source (Wilson in GNS Science Report 46:62 2009). Peak-to-trough tsunami heights of 55 cm were measured at Southport, Tasmania and a height of 1 m was measured in Jackson
Bay, New Zealand. The International Tsunami Symposium provided an ideal venue for illustration of the value of immediate real-time
assessment and provided an opportunity to further validate the real time forecasting capabilities with the scientific community
in attendance. A number of agencies with responsibility for tsunami forecast and/or warning, such as the NOAA Center for Tsunami
Research, the Pacific Tsunami Warning Center, GNS Science in New Zealand, the Australian Bureau of Meteorology and the European
Commission Joint Research Centre were all represented at the meeting and were able to demonstrate the use of state of the
art numerical models to assess the tsunami potential and provide warning as appropriate. 相似文献
296.
Elie Verleyen Dominic A. Hodgson Koen Sabbe Holger Cremer Steven D. Emslie John Gibson Brenda Hall Satoshi Imura Sakae Kudoh Gareth J. Marshall Andrew McMinn Martin Melles Louise Newman Donna Roberts Steve J. Roberts Shiv M. Singh Mieke Sterken Ines Tavernier Sergey Verkulich Evelien Van de Vyver Wim Van Nieuwenhuyze Bernd Wagner Wim Vyverman 《Earth》2011,104(4):199-212
We review the post-glacial climate variability along the East Antarctic coastline using terrestrial and shallow marine geological records and compare these reconstructions with data from elsewhere. Nearly all East Antarctic records show a near-synchronous Early Holocene climate optimum (11.5–9 ka BP), coinciding with the deglaciation of currently ice-free regions and the optimum recorded in Antarctic ice and marine sediment cores. Shallow marine and coastal terrestrial climate anomalies appear to be out of phase after the Early Holocene warm period, and show complex regional patterns, but an overall trend of cooling in the terrestrial records. A Mid to Late Holocene warm period is present in many East Antarctic lake and shallow coastal marine records. Although there are some differences in the regional timing of this warm period, it typically occurs somewhere between 4.7 and 1 ka BP, which overlaps with a similar optimum found in Antarctic Peninsula terrestrial records. The differences in the timing of these sometimes abrupt warm events in different records and regions points to a number of mechanisms that we have yet to identify. Nearly all records show a neoglacial cooling from 2 ka BP onwards. There is no evidence along the East Antarctic coastline for an equivalent to the Northern Hemisphere Medieval Warm Period and there is only weak circumstantial evidence in a few places for a cool event crudely equivalent in time to the Northern Hemisphere's Little Ice Age. There is a need for well-dated, high resolution climate records in coastal East Antarctica and particularly in Terre Adélie, Dronning Maud Land and Enderby Land to fully understand the regional climate anomalies, the disparity between marine and terrestrial records, and to determine the significance of the heterogeneous temperature trends being measured in the Antarctic today. 相似文献
297.
298.
Riphean basins of the central and western Siberian Platform 总被引:1,自引:0,他引:1
Sergey V. FrolovGrigorii G. Akhmanov Elena V. KozlovaOleg V. Krylov Ksenia A. SitarYuriy I. Galushkin 《Marine and Petroleum Geology》2011,28(4):906-920
The Siberian Platform is unique by its volume of Meso-Neoproterozoic sedimentary deposits. For about one billion years (∼1650-650 Ma) several sedimentary basins were developed here, resulting in the formation of several kilometers thickness of sedimentary cover. The Riphean (Mesoproterozoic-Lower Neoproterozoic) rocks are exposed mainly along platform peripheries. The most complete sections are represented by several megacycles. Each megacycle contains terrigenous series at the base and carbonate formations in the upper part. Several isolated and anisochronous basins were created during the Riphean on the territory of East Siberia. Some of them were intracratonic, others were developed on passive margins. Neoproterozoic orogeny along the platform boundaries resulted in re-organization of the Siberian basins, with extensive faulting, uplifting and erosion of the territories.In eastern Siberia, Riphean series contain large hydrocarbon accumulations. The reservoirs were formed mainly due to fracturing and leaching of carbonate strata (e.g. vugular carbonates of the pre-Vendian weathering crust). The Upper Proterozoic deposits are overlain by thick clayey-carbonate and saliferous-carbonate series of the Upper Vendian and Cambrian, isolating them from the upper sedimentary cover. The Riphean basins contained thick, organic rich, clayey and clayey carbonate. In some of them a hydrocarbon generation maximum took place at the end of the Riphean. The pre-Vendian erosion has removed a significant volume of Riphean sediments. During this time a majority of already formed hydrocarbon accumulations have been lost or degraded. Remaining Riphean series have generated hydrocarbons during the Paleozoic.Despite its complex history, the Riphean is still considered highly prospective, with source rocks developing at multiple levels and reservoirs occurring in both carbonate and clastic rocks. Discoveries of new oil-and-gas fields in East Siberia are likely, but will depend on integration of detailed seismic data and a large volume of core data for the correct prognosis of Riphean reservoir distribution. 相似文献
299.
An assessment of Arctic Ocean freshwater content changes from the 1990s to the 2006-2008 period 总被引:2,自引:0,他引:2
Benjamin Rabe Michael KarcherUrsula Schauer John M. TooleRichard A. Krishfield Sergey PisarevFrank Kauker Rüdiger GerdesTakashi Kikuchi 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(2):173-185
Unprecedented summer-season sampling of the Arctic Ocean during the period 2006-2008 makes possible a quasi-synoptic estimate of liquid freshwater (LFW) inventories in the Arctic Ocean basins. In comparison to observations from 1992 to 1999, LFW content relative to a salinity of 35 in the layer from the surface to the 34 isohaline increased by 8400±2000 km3 in the Arctic Ocean (water depth greater than 500 m). This is close to the annual export of freshwater (liquid and solid) from the Arctic Ocean reported in the literature.Observations and a model simulation show regional variations in LFW were both due to changes in the depth of the lower halocline, often forced by regional wind-induced Ekman pumping, and a mean freshening of the water column above this depth, associated with an increased net sea ice melt and advection of increased amounts of river water from the Siberian shelves. Over the whole Arctic Ocean, changes in the observed mean salinity above the 34 isohaline dominated estimated changes in LFW content; the contribution to LFW change by bounding isohaline depth changes was less than a quarter of the salinity contribution, and non-linear effects due to both factors were negligible. 相似文献
300.
O. A. Titov 《Astronomy Reports》2011,55(1):91-95
It is shown that geodetic VLBI observations can be used to estimate the external acceleration of the barycenter of the solar
system. This relies on the fact that, in special relativity, the acceleration of the motion of a coordinate origin relative
to reference points leads to a drift in the secular aberration, manifest as systematic proper motions of the reference points
in the direction of the acceleration vector. The VLBI time-delay equation is modified such that the acceleration vector appears
in explicit form. Formulas for a new form of the fundamental VLBI equation and its partial derivative with respect to the
acceleration are presented. 相似文献