全文获取类型
收费全文 | 80篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
大气科学 | 10篇 |
地球物理 | 23篇 |
地质学 | 30篇 |
海洋学 | 3篇 |
天文学 | 13篇 |
综合类 | 2篇 |
自然地理 | 3篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1996年 | 1篇 |
排序方式: 共有84条查询结果,搜索用时 15 毫秒
51.
The interannual variability of the European winter air temperature is partially caused by anomalous atmospheric circulation
and the associated advection of air masses, mainly linked to the North Atlantic Oscillation (NAO). However, a considerable
part of the temperature variability is not linearly described by atmospheric circulation anomalies. Here, a long control simulation
with a coupled atmosphere-ocean climate model is analyzed, with the goal of decomposing the European temperature (ET) anomalies
in a part linked to the anomalous atmospheric circulation and a residual. The amount of interannual variability of each contribution
is roughly 50%, although at subdecadal (overdecadal) time scales the variability of the residuals is dominant. These residuals
are found to be linked to temperature anomalies of the same sign in the whole North Atlantic and Greenland, in contrast to
the well-known temperature zonal seesaw associated with the NAO. The association between the residuals and other processes
in the North Atlantic has been also analyzed. The thermohaline circulation, closely connected in the model to the intensity
of the Gulf Stream, lags the evolution of the temperature residuals by several years and thus is not able to control their
evolution. The variability of the oceanic convection in the Northern North Atlantic, on the other hand, correlates with the
temperature residual at lags close to zero. It is hypothesized that oceanic convection produces a sea-surface temperature
fingerprint that leads to the ET residuals. The implications of these results for multi-year predictability and for empirical
climate reconstructions are discussed. 相似文献
52.
Janet M. Hergt L. Paul Bédard Stefanie M. Brueckner Klaus Peter Jochum Kathryn L. Linge Paul J. Sylvester Michael Wiedenbeck Jon D. Woodhead 《Geostandards and Geoanalytical Research》2008,32(4):397-398
In 2005 the Geostandards and Geoanalytical Research editorial team, in the true spirit of scientific endeavour, embarked on an experiment of our own. We decided to trial a new kind of review, somewhat different from those more typically observed in journals, and one that would provide readers with a summary of analytical developments across a broad range of topics appropriate to the Earth sciences. The first contribution of this kind appeared in 2005, and reported on developments in 2003 (Hergt et al. 2005). The second, this time a biennial review, was published in 2006 and reported on highlights of the 2004 and 2005 literature (Hergt et al. 2006). Based on reprint requests, positive remarks at conferences and strong citations we consider the experiment a resounding success and proudly present here the third in this series. This comprises six individual review sections that cover the main analytical technologies and topical application fields in geoanalysis and geochemistry, including geological and environmental reference materials, ICP‐thermal and secondary ionisation‐mass spectrometry, as well as neutron activation analysis, X‐ray fluorescence and atomic absorption spectrometry. 相似文献
53.
Schulze Stefanie S. Fischer Erica C. Hamideh Sara Mahmoud Hussam 《Natural Hazards》2020,104(1):901-925
Natural Hazards - Wildfire impacts on communities have become more pronounced in recent years as the intensity and frequency of wildfires have increased in densely populated areas of the... 相似文献
54.
An 11 m long sediment core ftorn Lama Lake, Northern Siberia, has been subjected to intense sedimentological, geochemical and rock magnetic analyses. According to a palynologic investigation the recovered sediments cover the whole Holocene and the late Pleistocene reaching back to about 17 ka. IRM acquisition experiments, hysteresis loop and back field as well as thermomagnetic measurements revealed magnetite in the pseudo-single domain range as the only remanence carrier. Sharp rock magnetic boundaries occur at 20 and 745 cm sub-bottom depth that are clearly linked to shifts in the median grain size of the magnetite. These boundaries are close to the present boundaries that bracket an anoxic zone between the subrecent and a late Pleistocene oxic section of the sediments. Within the anoxic section, magnetites are characterized by significantly larger median grain sizes but within a very narrow grain size range. The shift from fine grained magnetite within the oxic sediments to coarse grained magnetite is interpreted as the result of dissolution of the finest magnetite grains within the anoxic sediments. A significant shift of the Ti/Fe-ratio of the bulk sediment at a sub-bottom depth of 735 cm does not correspond to thermomagnetic properties, i.e. Curie-temperatures do not follow the variable Ti-content of the sediment. 相似文献
55.
Naga Manohar Velpuri Gabriel B. Senay Matthew Schauer C. Amanda Garcia Ramesh K. Singh MacKenzie Friedrichs Stefanie Kagone Jonathan Haynes Terrence Conlon 《水文研究》2020,34(8):1697-1713
Upper Klamath Lake (UKL) is the source of the Klamath River that flows through southern Oregon and northern California. The UKL Basin provides water for 81,000+ ha (200,000+ acres) of irrigation on the U.S. Bureau of Reclamation Klamath Project located downstream of the UKL Basin. Irrigated agriculture also occurs along the tributaries to UKL. During 2013–2016, water rights calls resulted in various levels of curtailment of irrigation diversions from the tributaries to UKL. However, information on the extent of curtailment, how much irrigation water was saved, and its impact on the UKL is unknown. In this study, we combined Landsat-based actual evapotranspiration (ETa) data obtained from the Operational Simplified Surface Energy Balance model with gridded precipitation and U.S. Geological Survey station discharge data to evaluate the hydrologic impact of the curtailment program. Analysis was performed for 2004, 2006, 2008–2010 (base years), and 2013–2016 (target years) over irrigated areas above UKL. Our results indicate that the savings from the curtailment program over the June to September time period were highest during 2013 and declined in each of the following years. The total on-field water savings was approximately 60 hm3 in 2013 and 2014, 44 hm3 in 2015, and 32 hm3 in 2016 (1 hm3 = 10,000 m3 or 810.7 ac-ft). The instream water flow changes or extra water available were 92, 68, 45, and 26 hm3, respectively, for 2013, 2014, 2015, and 2016. Highest water savings came from pasture and wetlands. Alfalfa showed the most decline in water use among grain crops. The resulting extra water available from the curtailment contributed to a maximum of 19% of the lake inflows and 50% of the lake volume. The Landsat-based ETa and other remote sensing datasets used in this study can be used to monitor crop water use at the irrigation district scale and to quantify water savings as a result of land-water management changes. 相似文献
56.
Pavel E. Tarasov Boris P. Ilyashuk Christian Leipe Stefanie Müller Birgit Plessen Philipp Hoelzmann Svetlana S. Kostrova Elena V. Bezrukova Hanno Meyer 《Boreas: An International Journal of Quaternary Research》2019,48(2):488-506
This study presents a multi‐proxy record from Lake Kotokel in the Baikal region at decadal‐to‐multidecadal resolution and provides a reconstruction of terrestrial and aquatic environments in the area during a 2000‐year interval of globally harsh climate often referred to as the Last Glacial Maximum (LGM). The studied lake is situated near the eastern shoreline of Lake Baikal, in a climatically sensitive zone that hosts boreal taiga and cold deciduous forests, cold steppe associations typical for northern Mongolia, and mountain tundra vegetation. The results provide a detailed picture of the period in focus, indicating (i) a driest phase (c. 24.0–23.4 cal. ka BP) with low precipitation, high summer evaporation, and low lake levels, (ii) a transitional interval of unstable conditions (c. 23.4–22.6 cal. ka BP), and (iii) a phase (c. 22.6–22.0 cal. ka BP) of relatively high precipitation (and moisture availability) and relatively high lake levels. One hotly debated issue in late Quaternary research is regional summer thermal conditions during the LGM. Our chironomid‐based reconstruction suggests at least 3.5 °C higher than present summer temperatures between c. 22.6 and 22.0 cal. ka BP, which are well in line with warmer and wetter conditions in the North Atlantic region inferred from Greenland ice‐cores. Overall, it appears that environments in central Eurasia during the LGM were affected by much colder than present winter temperatures and higher than present summer temperatures, although the effects of temperature oscillations were strongly influenced by changes in humidity. 相似文献
57.
Stefanie MONNINGER Eberhard FREY Ross ELGIN Helmut TISCHLINGER Julian SARTORI Petra SCHNEIDER 《地球学报》2010,31(Z1):52-52
Preservation of wing membranes in pterosaurs is only reported from a few localities in the world, namely from the Karatau Hills, Kazakhstan (Upper Jurassic), from the Solnhofen Lithographic Limestone, Germany (Upper Jurassic), the Daohugou Beds of China (Upper Jurassic or Lower Cretaceous) and the Crato and Santana Formations, Chapada do Araraipe, NE Brazil (Lower Cretaceous). 相似文献
58.
Michael A. DiSanti Geronimo L. Villanueva Stefanie N. Milam Boncho P. Bonev Michael J. Mumma William M. Anderson 《Icarus》2009,203(2):589-598
Volatile organic emissions were detected post-perihelion in the long-period Comet C/2006 M4 (SWAN) in October and November 2006. Our study combines target-of-opportunity infrared observations using the Cryogenic Echelle Spectrometer (CSHELL) at the NASA-IRTF 3-m telescope, and millimeter wavelength observations using the Arizona Radio Observatory (ARO) 12-m telescope. Five parent volatiles were measured with CSHELL (H2O, CO, CH3OH, CH4, and C2H6), and two additional species (HCN and CS) were measured with the ARO 12-m. These revealed highly depleted CO and somewhat enriched CH3OH compared with abundances observed in the dominant group of long-period (Oort cloud) comets in our sample and similar to those observed recently in Comet 8P/Tuttle. This may indicate highly efficient H-atom addition to CO at very low temperature (∼10-20 K) on the surfaces of interstellar (pre-cometary) grains. Comet C/2006 M4 had nearly “normal” C2H6 and CH4, suggesting a processing history similar to that experienced by the dominant group. When compared with estimated water production at the time of the millimeter observations, HCN was slightly depleted compared with the normal abundance in comets based on IR observations but was consistent with the majority of values from the millimeter. The ratio CS/HCN in C/2006 M4 was within the range measured in ten comets at millimeter wavelengths. The higher apparent H-atom conversion efficiency compared with most comets may indicate that the icy grains incorporated into C/2006 M4 were exposed to higher H-atom densities, or alternatively to similar densities but for a longer period of time. 相似文献
59.
Holger Class Anozie Ebigbo Rainer Helmig Helge K. Dahle Jan M. Nordbotten Michael A. Celia Pascal Audigane Melanie Darcis Jonathan Ennis-King Yaqing Fan Bernd Flemisch Sarah E. Gasda Min Jin Stefanie Krug Diane Labregere Ali Naderi Beni Rajesh J. Pawar Adil Sbai Sunil G. Thomas Laurent Trenty Lingli Wei 《Computational Geosciences》2009,13(4):409-434
60.
Stefanie Hufnagl-Eichiner Steven A. WolfLaurie E. Drinkwater 《Global Environmental Change》2011,21(2):530-539
Analysis and enhancement of “coupling” of social-ecological systems (SES) has emerged as a leading theme in sustainability studies. However, as an analytical concept that can support empirical research, coupling has not been adequately developed. This study synthesizes concepts from environmental sociology and ecological sciences to derive three criteria to assess adaptive coupling of an SES: prevention orientation, spatial targeting and temporal targeting. We apply our criteria to the case of nitrogen pollution from agriculture in the Mississippi River Basin (MRB) and resulting hypoxia in the Gulf of Mexico. We analyzed the federal agricultural research and development portfolio to assess the character of investments in knowledge creation and how patterns of investment have changed over time. While superficial assessment of the data suggests that public spending on nitrogen relevant research constitutes a substantive response to the problem of Gulf hypoxia, disaggregating the data highlights an ineffectual response. Specifically, we find that spatial and temporal targeting of investment of socioeconomic resources in the MRB is poorly aligned with the nature of ecological risks confronting the region. In addition to this policy relevant result, our study highlights the importance of geographically referenced data and attention to relevant scales of analysis. Further, the paper demonstrates opportunities to advance concepts and empirical understanding of social-ecological coupling through interdisciplinary research on interfaces that mediate interactions in SES, for example publicly funded research aimed at agricultural practice and environmental conservation in the MRB. 相似文献