全文获取类型
收费全文 | 194篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 3篇 |
大气科学 | 4篇 |
地球物理 | 95篇 |
地质学 | 40篇 |
海洋学 | 10篇 |
天文学 | 28篇 |
自然地理 | 17篇 |
出版年
2022年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 14篇 |
2009年 | 22篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 12篇 |
2005年 | 17篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1953年 | 1篇 |
1936年 | 1篇 |
1913年 | 2篇 |
排序方式: 共有197条查询结果,搜索用时 15 毫秒
41.
Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network,
vol. 34, no. 7, July 2009 (on the Internet at ). Edited by scientists at the Smithsonian, this bulletin includes reports provided by a worldwide network of correspondents.
The reports contain the names and contact information for all sources. Please note that these reports are preliminary and
subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism,
seismic unrest, monitoring data, and field observations. 相似文献
42.
Edward Venzke Sally Kuhn Sennert Richard Wunderman Catie Carter 《Bulletin of Volcanology》2010,72(6):769-770
Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network,
vol. 35, no. 2, February 2010 (on the Internet at ). Edited by scientists at the Smithsonian, this bulletin includes reports provided by a worldwide network of correspondents.
The reports contain the names and contact information for all sources. Please note that these reports are preliminary and
subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism,
seismic unrest, monitoring data, and field observations. 相似文献
43.
Eduard Bauerfeind Eva-Maria Nöthig Agnieszka Beszczynska Kirsten Fahl Lars Kaleschke Kathrin Kreker Michael Klages Thomas Soltwedel Christiane Lorenzen Jan Wegner 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(9):1471-1487
Since 2000 long-term measurements of vertical particle flux have been performed with moored sediment traps at the long-term observatory HAUSGARTEN in the eastern Fram Strait (79°N/4°E). The study area, which is seasonally covered with ice, is located in the confluence zone of the northward flowing warm saline Atlantic water with cold, low salinity water masses of Arctic origin. Current projections suggest that this area is particularly vulnerable to global warming. Total matter fluxes and components thereof (carbonate, particulate organic carbon and nitrogen, biogenic silica, biomarkers) revealed a bimodal seasonal pattern showing elevated sedimentation rates during May/June and August/September. Annual total matter flux (dry weight, DW) at ~300 m depth varied between 13 and 32 g m?2 a?1 during 2000 and 2005. Of this total flux 6–13% was due to CaCO3, 4–21% to refractory particulate organic carbon (POC), and 3–8% to biogenic particulate silica (bPSi). The annual flux of all biogenic components together was almost constant during the period studied (8.5–8.8 g m?2 a?1), although this varied from 27% to 67% of the total annual flux. The fraction was lowest in a year characterized by the longest duration of ice coverage (91 and 70 days for the calendar year and summer season, May–September, respectively). Biomarker analyses revealed that organic matter originating from marine sources was present in excess of terrigenious material in the sedimented matter throughout most of the study period. Fluxes of recognizable phyto- and protozooplankton cells amounted up to 60×106 m?2 d?1. Diatoms and coccolithophorids were the most abundant organisms. Diatoms, mainly pennate species, dominated during the first years of the investigation. A shift in the composition occurred during the last year when numbers of diatoms declined considerably, leading to a dominance of coccolithoporids. This was also reflected in a decrease in the sedimentation of bPSi. The sedimentation of biogenic matter, however, did not differ from the amount observed during the previous years. Among the larger organisms, pteropods at times contributed significantly to both the total matter and CaCO3, fluxes. 相似文献
44.
Cumulative and differential cumulative seismic strain release of shallow earthquakes during 1964 through 1972 show significant time-delayed correlation for many of the rises and/or sinks of tectonic plate boundaries for the Atlantic, Indian and Pacific oceans. For the Pacific, time delays are almost exclusively from areas of higher to areas of lower strain release, and could imply viscous stress relaxation along or near the lithosphere—asthenosphere boundary. Seismically determined slip rates for many of the subduction zones during 1964–1972 are lower than those of the preceding part of the century by a factor of 5. The significant correlation between many rises and sinks suggests worldwide interaction and coupling of plate motion. 相似文献
45.
46.
Eduard?P.?KontarEmail author Michele?Piana Anna?Maria?Massone A.?Gordon?Emslie John?C.?Brown 《Solar physics》2004,225(2):293-309
Hard X-ray spectra in solar flares provide knowledge of the electron spectrum that results from acceleration and propagation in the solar atmosphere. However, the inference of the electron spectra from solar X-ray spectra is an ill-posed inverse problem. Here, we develop and apply an enhanced regularization algorithm for this process making use of physical constraints on the form of the electron spectrum. The algorithm incorporates various features not heretofore employed in the solar flare context: Generalized Singular Value Decomposition (GSVD) to deal with different orders of constraints; rectangular form of the cross-section matrix to extend the solution energy range; regularization with various forms of the smoothing operator; and preconditioning of the problem. We show by simulations that this technique yields electron spectra with considerably more information and higher quality than previous algorithms. 相似文献
47.
48.
Davorka Herak Marijan Herak Eduard Prelogovi Snjeana Markui
eljko Markulin 《Tectonophysics》2005,398(3-4):167-180
We present analyses of one of the strongest earthquake sequences ever recorded within the Adriatic microplate, which occurred near the Jabuka island in the very centre of the Adriatic Sea. The mainshock (29 March 2003, 17:42, ML=5.5) was preceded by over 150 foreshocks, and followed by many aftershocks, over 4600 of which were recorded on the closest station HVAR (about 90 km to the east). As the epicentre was in the open sea and due to the absence of nearby stations, we were able to confidently locate only 597 events. Hypocentral locations were computed by a grid-search algorithm after seven iterations of refining hypocentres and adjusting station corrections. Epicentres lie in a well-defined area of about 300 km2, just to the W and NW of the Jabuka island. The vertical cross-sections reveal that hypocentres dip to the NE, closely matching faults from the Jabuka-Andrija fault system, as identified on the available reflection profiles in the area. The fault-plane solution of the main shock based on the first-motion polarity readings agrees well with the CMT solutions and indicates faulting caused by a S–N directed tectonic pressure, on a reverse, dip-slip fault. This is in very good agreement with the seismotectonic framework of the area. These earthquakes are important as they identify the Jabuka-Andrija fault system as an active one, which can significantly influence seismic hazard on the islands in the central Adriatic archipelago and on the Croatian coast between Zadar and Split. Along with several other sequences which occurred in the last two decades, they force us to change our notion of Adria as nearly aseismic, compact and rigid block. In fact, it turns out that recent seismicity of the Central Adriatic Sea is comparable to the seismicity of several well known earthquake-prone areas in the circum-Adriatic region. 相似文献
49.
Edward Venzke 《Bulletin of Volcanology》2006,68(4):401-403
Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, vol. 30, no. 5, May 2005 (on the Internet at http://www.volcano.si.edu/). Edited by scientists at the Smithsonian, this
bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information
for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail.
The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations. 相似文献
50.
Edward Venzke 《Bulletin of Volcanology》2006,69(2):233-235
Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, vol. 31, no. 1, January 2006 (on the Internet at ). Edited by scientists at the Smithsonian, this bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations. 相似文献