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排序方式: 共有177条查询结果,搜索用时 31 毫秒
31.
32.
Drift probabilities for Icelandic cod larvae 总被引:1,自引:0,他引:1
33.
Reloca Slide: an ~24 km3 submarine mass‐wasting event in response to over‐steepening and failure of the central Chilean continental slope 下载免费PDF全文
Eduardo Contreras‐Reyes David Vlker Jrg Bialas Eduardo Moscoso Ingo Grevemeyer 《地学学报》2016,28(4):257-264
Reloca Slide is the relict of an ~24‐km3 submarine slope collapse at the base of the convergent continental margin of central Chile. Bathymetric and seismic data show that directly to the north and south of the slide the lower continental slope is steep (~10°), the deformation front is shifted landwards by 10–15 km, and the frontal accretionary prism is uplifted. In contrast, ~80 km to the north the lower continental margin presents a lower slope angle of about 4° and a wide frontal accretionary prism. We propose that high effective basal friction conditions at the base of the accretionary prism favoured basal accretion of sediment and over‐steepening of the continental slope, producing massive submarine mass wasting in the Reloca region. This area also spatially correlates with a zone of low coseismic slip of the 2010 Maule megathrust earthquake, which is consistent with high basal frictional coefficients. 相似文献
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Atmospheric spectroscopy of extrasolar planets is an intricate business. Atmospheric signatures typically require a photometric precision of 1×10?4 in flux over several hours. Such precision demands high instrument stability as well as an understanding of stellar variability and an optimal data reduction and removal of systematic noise. In the context of the EChO mission concept, we here discuss the data reduction and analysis pipeline developed for the EChO end-to-end simulator EChOSim. We present and discuss the step by step procedures required in order to obtain the final exoplanetary spectrum from the EChOSim ‘raw data’ using a simulated observation of the secondary eclipse of the hot-Neptune 55 Cnc e. 相似文献
36.
China's rapid growth and structural change since the reform in the late 1970s have generated many intriguing issues for scholarly research. This paper notices the drastic rise of China in foreign investment, export, and ICT production. Through a comprehensive review of the literature on globalization, industrial restructuring and regional development, this paper holds that the research on China is embedded in China's reform process, as well as theoretical development in economic geography. It highlights the important role of institutions and global-local interactions in industrial and regional development. 相似文献
37.
Crustal thinning beneath the Rwenzori region, Albertine rift, Uganda, from receiver-function analysis 总被引:1,自引:1,他引:0
Ingo Wölbern G. Rümpker A. Schumann A. Muwanga 《International Journal of Earth Sciences》2010,99(7):1545-1557
The Rwenzori mountains in western Uganda, with a maximum elevation of more than 5,000 m, are located within the Albertine
rift valley. We have deployed a temporary seismic network on the Ugandan side of the mountain range to study the seismic velocity
structure of the crust and upper mantle beneath this section of the rift. We present results from a receiver-function study
revealing a simple crustal structure along the eastern rift flank with a more or less uniform crustal thickness of about 30 km.
The complexity of inner-crustal structures increases drastically within the Rwenzori block. We apply different inversion techniques
to obtain reliable results for the thickness of the crust. The observations expose a significantly thinner crust beneath the
Rwenzori range with thickness values ranging from about 20–28 km beneath northern and central parts of the mountains. Our
study therefore indicates the absence of a crustal root beneath the Rwenzori block. Beneath the Lake Edward and Lake George
basins we detect the top of a layer of significantly reduced S-wave velocity at 15 km depth. This low-velocity layer may be
attributed to the presence of partial melt beneath a region of recent volcanic activity. 相似文献
38.
Atmospheric moisture transport from the Atlantic to the Pacific basin plays an important role in regulating North Atlantic salinity and thus the strength of the thermohaline circulation. Potential changes in the strength of this moisture transport are investigated for two different climate-change scenarios: North Atlantic cooling representative of Heinrich events, and increased greenhouse gas (GHG) forcing. The effect of North Atlantic cooling is studied using a coupled regional model with comparatively high resolution that successfully simulates Central American gap winds and other important aspects of the region. Cooler North Atlantic sea surface temperature (SST) in this model leads to a regional decrease of atmospheric moisture but also to an increase in wind speed across Central America via an anomalous pressure gradient. The latter effect dominates, resulting in a 0.13 Sv (1 Sv = 106 m3 s?1) increase in overall moisture transport to the Pacific basin. In fresh water forcing simulations with four different general circulation models, the wind speed effect is also present but not strong enough to completely offset the effect of moisture decrease except in one model. The influence of GHG forcing is studied using simulations from the Intergovernmental Panel on Climate Change archive. In these simulations atmospheric moisture increases globally, resulting in an increase of moisture transport by 0.25 Sv from the Atlantic to Pacific. Thus, in both scenarios, moisture transport changes act to stabilize the thermohaline circulation. The notion that the Andes effectively block moisture transport from the Atlantic to the Pacific basin is not supported by the simulations and atmospheric reanalyses examined here. This indicates that such a blocking effect does not exist or else that higher resolution is needed to adequately represent the steep orography of the Andes. 相似文献
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Summary Quantitative sunglitter radiance modulations at the ocean surface due to internal waves were calculated applying a simple
first order theory. The results have been compared with the image data of internal wave signatures northeast of Nantucket
Shoals off the coast of Massachusetts, U.S.A., taken by the Earth Terrain Camera (ETC) during the Skylab mission. The maximum
magnitudes of sunglitter radiance modulations predicted by the theory are comparable to the satellite image data. The extreme
values of calculated modulations depend only weakly on the wavelength of the internal wave signature. This is consistent with
the analysed ETC data. On the other hand, the shapes of simulated and measured image intensity transects across an internal
wave packet are different. This may possibly be explained by the assumed idealized sinusoidal type of thermocline used in
the calculations. The theory predicts that sunglint signatures of internal waves are advected relative to positions of extreme
slope regions of the thermocline due to currents.
Strahldichtemodulation des Sonnenglitzerns durch interne Wellen
Zusammenfassung Quantitative Strahldichtemodulationen des Sonnenglitzerns an der Meeresoberfl?che durch interne Wellen werden unter Verwendung einer einfachen ersten Ordnungstheorie berechnet. Die Ergebnisse werden mit Bilddaten von internen Wellensignaturen nord?stlich von Nantucket Shoals vor der Küste von Massachusetts, U.S.A., verglichen, die w?hrend der Skylab-Mission von der Erdbeobachtungskamera (ETC) aufgenommen wurden. Die Werte der maximalen Strahldichtemodulation des Sonnenglitzerns, die von der Theorie vorhergesagt werden, sind mit den Satellitenbilddaten vergleichbar. Die Extremwerte der berechneten Modulationen h?ngen nur schwach von der Wellenl?nge der internen Wellensignaturen ab. Dieses stimmt mit den analysierten ETC Daten überein. Auf der anderen Seite sind die Kurvenverl?ufe zwischen den simulierten und gemessenen Bildintensit?tsprofilen entlang eines internen Wellenpaketes unterschiedlich. Dieses kann m?glicherweise durch den angenommenen idealisierten sinusf?rmigen Typ der Thermokline erkl?rt werden, der für die Berechnungen verwendet wurde. Die Theorie macht die Vorhersage, da? Signaturen des Sonnenglitzerns von internen Wellen durch Str?mungen advektiert werden relativ zu den Positionen der extremen Neigungsregionen der Thermokline.相似文献