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431.
Anne Marie Treguier Claire Gourcuff Pascale Lherminier Herle Mercier Bernard Barnier Gurvan Madec Jean-Marc Molines Thierry Penduff Lars Czeschel Claus Böning 《Ocean Dynamics》2006,56(5-6):568-580
Numerical models are used to estimate the meridional overturning and transports along the paths of two hydrographic cruises,
carried out in 1997 and 2002 from Greenland to Portugal. We have examined the influence of the different paths of the two
cruises and found that it could explain 0.4 to 2 Sv of difference in overturning (the precise value is model-dependent). Models
show a decrease in the overturning circulation between 1997 and 2002, with different amplitudes. The CLIPPER ATL6 model reproduces
well the observed weakening of the overturning in density coordinates between the cruises; in the model, the change is due
to the combination of interannual and high-frequency forcing and internal variability associated with eddies and meanders.
Examination of the -coordinate overturning reveals model–data discrepancies: the vertical structure in the models does not change as much as
the observed one. The East Greenland current variability is mainly wind-forced in the ATL6 model, while fluctuations due to
eddies and instabilities explain a large part of the North Atlantic Current variability. The time-residual transport of dense
water and heat due to eddy correlations between currents and properties is small across this section, which is normal to the
direction of the main current. 相似文献
432.
Kyra Marie Reynolds 《GeoJournal》2017,82(4):701-719
In the last few decades, a growing number of theorists have suggested that the natural environment can be a platform for promoting cooperation between former adversaries and can perhaps contribute to peacebuilding. However, environmental cooperation has not lived up to these claims. In many cases, such cooperation has largely been ineffective and/or inequitable. Therefore, there is a growing awareness that we cannot be overly optimistic at the first signs of ‘cooperation’. It is argued that this reality results from the great complexity inherent in cooperative interactions. This paper explores the nature of such cooperation in two Israeli–Palestinian case studies. The Israeli–Palestinian conflict is one of the longest-running protracted conflicts in the modern era and is currently characterised by a political stalemate. However, there is also a willingness by some at the local level to cooperate. Therefore Israel/Palestine provides an ideal case study. The findings of the paper illuminate the complex nature of environmental cooperation and reveal that even with the presence of good intentions, cooperation at the subnational level is impacted by the broader socio-political structures and contexts within which it is embedded. In these case studies, this is negatively affecting both the nature and scale of the processes and outcomes. Ultimately, these factors are making such interactions limited, unstable and/or prone to collapse. The paper concludes that only by conducting in-depth multi-tiered and context-specific analyses of cooperative processes and subsequently finding ways to overcome the identified barriers can we move towards more successful environmental cooperation. 相似文献
433.
Marie Grace Pamela G. Faylona Claire E. Lazareth Anne‐Marie Smah Sandrine Caquineau Hugues Boucher Wilfredo P. Ronquillo 《Geoarchaeology》2011,26(6):888-901
Tridacnidae shells, a valuable archive of past environments, are common in the Balobok Rockshelter archaeological site on Sanga‐Sanga Island in the south Philippines. This site was occupied during the mid‐Holocene (ca. 5000–8800 14C yr B.P.), a period of Neolithic cultural expansion in the Philippines. This paper focuses on the preservation of two shell specimens, Hippopus hippopus and Tridacna maxima, unearthed from two mid‐Holocene layers within the rockshelter. The shells' mineralogy and microstructure (prismatic and crossed‐lamellar) were studied using micro‐Fourier transform infrared spectroscopy and scanning electron microscopy to determine if the samples were suitable as paleoenvironmental records. Both shells are still aragonitic but aragonite crystals of both microstructure types are partly dissolved. This dissolution, characteristic of meteoric water alteration, precludes their utility in paleoenvironmental geochemical studies. Nevertheless, these shells are abundant in archaeological sites in the region and may be better preserved in other depositional contexts; more studies on Philippine Tridacnidae shell diagenesis are needed. © 2011 Wiley Periodicals, Inc. 相似文献
434.