全文获取类型
收费全文 | 407篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 10篇 |
大气科学 | 53篇 |
地球物理 | 51篇 |
地质学 | 116篇 |
海洋学 | 20篇 |
天文学 | 146篇 |
综合类 | 2篇 |
自然地理 | 20篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 17篇 |
2012年 | 15篇 |
2011年 | 20篇 |
2010年 | 29篇 |
2009年 | 17篇 |
2008年 | 18篇 |
2007年 | 21篇 |
2006年 | 20篇 |
2005年 | 10篇 |
2004年 | 23篇 |
2003年 | 23篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 13篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 9篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1971年 | 2篇 |
1970年 | 5篇 |
1967年 | 4篇 |
1962年 | 2篇 |
1914年 | 2篇 |
1913年 | 2篇 |
1912年 | 4篇 |
排序方式: 共有418条查询结果,搜索用时 31 毫秒
1.
Joel Sanchez-Bermudez Florentin Millour Fabien Baron Roy van Boekel Laurent Bourgès Gilles Duvert Paulo J. V. Garcia Nuno Gomes Karl-Heinz Hofmann Thomas Henning Jacob W. Isbell Bruno Lopez Alexis Matter J-Uwe Pott Dieter Schertl Eric Thiébaut Gerd Weigelt John Young 《Experimental Astronomy》2018,46(3):457-473
During the last two decades, the first generation of beam combiners at the Very Large Telescope Interferometer has proved the importance of optical interferometry for high-angular resolution astrophysical studies in the near- and mid-infrared. With the advent of 4-beam combiners at the VLTI, the u ? v coverage per pointing increases significantly, providing an opportunity to use reconstructed images as powerful scientific tools. Therefore, interferometric imaging is already a key feature of the new generation of VLTI instruments, as well as for other interferometric facilities like CHARA and JWST. It is thus imperative to account for the current image reconstruction capabilities and their expected evolutions in the coming years. Here, we present a general overview of the current situation of optical interferometric image reconstruction with a focus on new wavelength-dependent information, highlighting its main advantages and limitations. As an Appendix we include several cookbooks describing the usage and installation of several state-of-the art image reconstruction packages. To illustrate the current capabilities of the software available to the community, we recovered chromatic images, from simulated MATISSE data, using the MCMC software SQUEEZE. With these images, we aim at showing the importance of selecting good regularization functions and their impact on the reconstruction. 相似文献
2.
3.
4.
Henning Lorenz David G. Gee Evgeny Korago Galina Kovaleva William C. McClelland Jane A. Gilotti Dirk Frei 《地学学报》2013,25(6):496-503
The Novaya Zemlya fold‐and‐thrust‐belt is the northern continuation of the late Palaeozoic Uralide Orogen. Little is known about its deeper structure and the basement history of the adjacent Barents and Kara shelves. Based on geological evidence and detrital zircon analysis of 28 samples from the northeastern and stratigraphically deepest part of the archipelago, we demonstrate that Cambro‐Ordovician turbidite‐dominated deposition was almost exclusively sourced from rocks consolidated during the Timanian orogeny (Timanian basement). A profound change in provenance occurred near the end of the Ordovician. Over 90% of the zircons from Silurian and about 80% from Devonian strata have ages characteristic of the Sveconorwegian Orogen, implying uplift of these rocks in the vicinity of Novaya Zemlya. The presence of Sveconorwegian and Grenvillian rocks in the high Arctic suggests revision of recent reconstructions of the Rodinia supercontinent, its break‐up and subsequent Caledonian orogeny. 相似文献
5.
Thermophysical properties of Almahata Sitta meteorites (asteroid 2008 TC3) for high‐fidelity entry modeling 下载免费PDF全文
Stefan Loehle Peter Jenniskens Hannah Böhrk Thomas Bauer Henning Elsäβer Derek W. Sears Michael E. Zolensky Muawia H. Shaddad 《Meteoritics & planetary science》2017,52(2):197-205
Asteroid 2008 TC3 was characterized in a unique manner prior to impacting Earth's atmosphere, making its October 7, 2008, impact a suitable field test for or validating the application of high‐fidelity re‐entry modeling to asteroid entry. The accurate modeling of the behavior of 2008 TC3 during its entry in Earth's atmosphere requires detailed information about the thermophysical properties of the asteroid's meteoritic materials at temperatures ranging from room temperature up to the point of ablation (T ~ 1400 K). Here, we present measurements of the thermophysical properties up to these temperatures (in a 1 atm. pressure of argon) for two samples of the Almahata Sitta meteorites from asteroid 2008 TC3: a thick flat‐faced ureilite suitably shaped for emissivity measurements and a thin flat‐faced EL6 enstatite chondrite suitable for diffusivity measurements. Heat capacity was determined from the elemental composition and density from a 3‐D laser scan of the sample. We find that the thermal conductivity of the enstatite chondrite material decreases more gradually as a function of temperature than expected, while the emissivity of the ureilitic material decreases at a rate of 9.5 × 10?5 K?1 above 770 K. The entry scenario is the result of the actual flight path being the boundary to the load the meteorite will be affected with when entering. An accurate heat load prediction depends on the thermophysical properties. Finally, based on these data, the breakup can be calculated accurately leading to a risk assessment for ground damage. 相似文献
6.
Snow carrots after the Chelyabinsk event and model implications for highly porous solar system objects 下载免费PDF全文
Robert Luther Natalia Artemieva Marina Ivanova Cyril Lorenz Kai Wünnemann 《Meteoritics & planetary science》2017,52(5):979-999
After the catastrophic disruption of the Chelyabinsk meteoroid, small fragments formed funnels in the snow layer covering the ground. We constrain the pre‐impact characteristics of the fragments by simulating their atmospheric descent with the atmospheric entry model. Fragments resulting from catastrophic breakup may lose about 90% of their initial mass due to ablation and reach the snow vertically with a free‐fall velocity in the range of 30–90 m s?1. The fall time of the fragments is much longer than their cooling time, and, as a consequence, fragments have the same temperature as the lower atmosphere, i.e., of about ?20 °C. Then, we use the shock physics code iSALE to model the penetration of fragments into fluffy snow, the formation of a funnel and a zone of denser snow lining its walls. We examine the influence of several material parameters of snow and present our best‐fit model by comparing funnel depth and funnel wall characteristics with observations. In addition, we suggest a viscous flow approximation to estimate funnel depth dependence on the meteorite mass. We discuss temperature gradient metamorphism as a possible mechanism which allows to fill the funnels with denser snow and to form the observed “snow carrots.” This natural experiment also helps us to calibrate the iSALE code for simulating impacts into highly porous matter in the solar system including tracks in the aerogel catchers of the Stardust mission and possible impact craters on the 67P/Churyumov‐Gerasimenko comet observed recently by the Rosetta mission. 相似文献
7.
Nicolas Van Nieuwenhove Henning A. Bauch Frédérique Eynaud Evguenia Kandiano Elsa Cortijo Jean-Louis Turon 《Quaternary Science Reviews》2011,30(7-8):934-946
The Last Interglacial (Marine Isotopic Stage or MIS 5e) surface ocean heat flux from the Rockall Basin (NE Atlantic) towards the Arctic Ocean was reconstructed by analysing dinoflagellate cyst (dinocyst) assemblages in four sediment cores. Together with records of stable isotopes and ice-rafted detritus, the assemblage data reflect the northward retreat of ice(berg)-laden waters and the gradual development towards interglacial conditions at the transition from the Saalian deglaciation (Termination II) into MIS 5e. At the Rockall Basin, this onset of the Last Interglacial is soon followed by the appearance of the thermophilic dinocyst species Spiniferites mirabilis, with relative abundances higher than those observed at present in the area. North of the Iceland-Scotland Ridge, however, S. mirabilis only appears in significant numbers during late MIS 5e, between ~118 and 116.5 ka. Hence, fully marine Last Interglacial conditions with most intense Atlantic surface water influence occurred during late MIS 5e in the Nordic seas, and consequently also farther north in the Arctic Ocean, and at times when northern hemisphere summer insolation was already significantly decreased. The stratigraphic position of this Late Interglacial optimum is supported by planktic foraminifers and contrasts with the timing of the early Holocene climatic optimum in this area. We interpret the delayed northward expansion of Atlantic waters towards the polar latitudes as a result of the Saalian ice sheet deglaciation and its specific impact on the subsequent water mass evolution in this region. 相似文献
8.
Henning A. Bauch Evguenia S. Kandiano Jan Helmke Nils Andersen Antoni Rosell-Mele Helmut Erlenkeuser 《Quaternary Science Reviews》2011,30(15-16):1813-1818
New multiproxy marine data of the Eemian interglacial (MIS5e) from the Norwegian Sea manifest a cold event with near-glacial surface ocean summer temperatures (3–4 °C). This mid-Eemian cooling divided the otherwise relatively warm interglacial climate and was associated with widespread expansions of winter sea-ice and polar water masses due to changes in atmospheric circulation and ocean stability. While the data also verify a late rather than early last interglacial warm peak, which is in general disharmony with northern hemisphere insolation maximum and the regional climatic progression of the early Holocene, the cold event itself was likely instrumental for delaying the last interglacial climate development in the Polar North when compared with regions farther south. Such a ‘climatic decoupling’ of the Polar region may bear profound implications for the employment of Eemian conditions to help evaluate the present and future state of the Arctic cryosphere during a warming interglacial. 相似文献
9.
10.
Charles L. Henning 《International Journal of Earth Sciences》1912,3(1):35-50
Ohne Zusammenfassung 相似文献