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41.
Weronika Gorczyk Hugh Smithies Fawna Korhonen Heather Howard Raphael Quentin De Gromard 《地学前缘(英文版)》2015,6(1):23-37
The Musgrave Province developed at the nexus of the North,West and South Australian cratons and its Mesoproterozoic evolution incorporates a 100 Ma period of ultra-high temperature(UHT) metamorphism from ca.1220 to ca.1120 Ma.This was accompanied by high-temperature A-type granitic magmatism over an 80 Ma period,sourced in part from mantle-derived components and emplaced as a series of pulsed events that also coincide with peaks in UHT metamorphism.The tectonic setting for this thermal event(the Musgrave Orogeny) is thought to have been intracontinental and the lithospheric architecture of the region is suggested to have had a major influence on the thermal evolution.We use a series of two dimensional,fully coupled thermo-mechanical-petrological numerical models to investigate the plausibility of initiating and prolonging UHT conditions under model setup conditions appropriate to the inferred tectonic setting and lithospheric architecture of the Musgrave Province.The results support the inferred tectonic framework for the Musgrave Orogeny,predicting periods of UHT metamorphism of up to 70 Ma,accompanied by thin crust and extensive magmatism derived from both crustal and mantle sources.The results also appear to be critically dependent upon the specific location of the Musgrave Province,constrained between thicker cratonic masses. 相似文献
42.
Raphael J. Nawrotzki Hannah Brenkert-Smith Lori M. Hunter Patricia A. Champ 《社会与自然资源》2014,27(2):215-225
The number of people living in wildfire-prone wildland–urban interface (WUI) communities is on the rise. However, no prior study has investigated wildfire-induced residential relocation from WUI areas after a major fire event. To provide insight into the association between sociodemographic and sociopsychological characteristics and wildfire-related intention to move, we use data from a survey of WUI residents in Boulder and Larimer counties, Colorado. The data were collected 2 months after the devastating Fourmile Canyon fire destroyed 169 homes and burned more than 6,000 acres of public and private land. Although this study is working with a small migrant sample, logistic regression models demonstrate that survey respondents intending to move in relation to wildfire incidence do not differ sociodemographically from their nonmigrant counterparts. They do, however, show significantly higher levels of risk perception. Investigating destination choices shows a preference for short-distance moves. 相似文献
43.
Alexandre Raphael Cabral Harilaos Tsikos Yasuyuki Muramatsu Tomoko Sekiya 《Chemie der Erde / Geochemistry》2011,71(3):297-301
A reconnaissance bulk geochemical study was carried out on ten samples from the Palaeoproterozoic Hotazel iron formation, South Africa, with emphasis on iodine and bromine abundances. Very low-absolute contents recorded for both halogens, i.e. 0.08–0.26 μg/g for I and 0.35–1.23 μg/g for Br, indicate that they should largely have been lost during burial diagenesis. Bulk I/Br ratios (0.08–0.50), however, show marginal variation across the selected sample set and broadly resemble those that typify recent marine sediments containing organic matter. The possibility emerges that both elements are organic matter-sourced and may thus provide a potential proxy for the role of biological processes during deposition and diagenesis of Precambrian iron formations. 相似文献
44.
Do probabilistic expert elicitations capture scientists’ uncertainty about climate change? 总被引:1,自引:0,他引:1
Antony Millner Raphael Calel David A. Stainforth George MacKerron 《Climatic change》2013,116(2):427-436
Expert elicitation studies have become important barometers of scientific knowledge about future climate change (Morgan and Keith, Environ Sci Technol 29(10), 1995; Reilly et al., Science 293(5529):430–433, 2001; Morgan et al., Climate Change 75(1–2):195–214, 2006; Zickfeld et al., Climatic Change 82(3–4):235–265, 2007, Proc Natl Acad Sci 2010; Kriegler et al., Proc Natl Acad Sci 106(13):5041–5046, 2009). Elicitations incorporate experts’ understanding of known flaws in climate models, thus potentially providing a more comprehensive picture of uncertainty than model-driven methods. The goal of standard elicitation procedures is to determine experts’ subjective probabilities for the values of key climate variables. These methods assume that experts’ knowledge can be captured by subjective probabilities—however, foundational work in decision theory has demonstrated this need not be the case when their information is ambiguous (Ellsberg, Q J Econ 75(4):643–669, 1961). We show that existing elicitation studies may qualitatively understate the extent of experts’ uncertainty about climate change. We designed a choice experiment that allows us to empirically determine whether experts’ knowledge about climate sensitivity (the equilibrium surface warming that results from a doubling of atmospheric CO2 concentration) can be captured by subjective probabilities. Our results show that, even for this much studied and well understood quantity, a non-negligible proportion of climate scientists violate the choice axioms that must be satisfied for subjective probabilities to adequately describe their beliefs. Moreover, the cause of their violation of the axioms is the ambiguity in their knowledge. We expect these results to hold to a greater extent for less understood climate variables, calling into question the veracity of previous elicitations for these quantities. Our experimental design provides an instrument for detecting ambiguity, a valuable new source of information when linking climate science and climate policy which can help policy makers select decision tools appropriate to our true state of knowledge. 相似文献
45.
Juliette Tea-Yass Zli Bruno Digbehi Konan Raphael Yao Boblai Victor Glohi 《Journal of African Earth Sciences》1999,29(4):270
The palynological analysis of the core samples from the interval 1722–1777 m of well IVCO-25, located in the Abidjan margin, has revealed a rich microflora composed of Pteridophyta and Chlorophyta spores combined with Palmaceae and Proteaceae pollen grains. This palynoflora suggests a vegetation developed under a hot and humid tropical climate, suggestive of estuarine conditions. The microplankton, composed of various species of dinocysts, were indicative of a Campanian age for the studied interval. 相似文献
46.
Anthony Boccaletti Jean Schneider Wes Traub Pierre-Olivier Lagage Daphne Stam Raffaele Gratton John Trauger Kerri Cahoy Frans Snik Pierre Baudoz Raphael Galicher Jean-Michel Reess Dimitri Mawet Jean-Charles Augereau Jenny Patience Marc Kuchner Mark Wyatt Eric Pantin Anne-Lise Maire Christophe Vérinaud Samuel Ronayette Didier Dubreuil Michiel Min Michiel Rodenhuis Dino Mesa Russ Belikov Olivier Guyon Motohide Tamura Naoshi Murakami Ingrid Mary Beerer 《Experimental Astronomy》2012,34(2):355-384
SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) is a five-year M-class mission proposed to ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets and circumstellar disks in the visible (450?C900 nm) at a spectral resolution of about 40 using both spectroscopy and polarimetry. By 2020/2022, present and near-term instruments will have found several tens of planets that SPICES will be able to observe and study in detail. Equipped with a 1.5 m telescope, SPICES can preferentially access exoplanets located at several AUs (0.5?C10?AU) from nearby stars (<25 pc) with masses ranging from a few Jupiter masses to Super Earths (??2 Earth radii, ??10 M??) as well as circumstellar disks as faint as a few times the zodiacal light in the Solar System. 相似文献
47.
David Mimoun Mark A. Wieczorek Leon Alkalai W. Bruce Banerdt David Baratoux Jean-Louis Bougeret Sylvain Bouley Baptiste Cecconi Heino Falcke Joachim Flohrer Raphael F. Garcia Robert Grimm Matthias Grott Leonid Gurvits Ralf Jaumann Catherine L. Johnson Martin Knapmeyer Naoki Kobayashi Alexander Konovalenko David Lawrence Mathieu Le Feuvre Philippe Lognonné Clive Neal Jürgen Oberst Nils Olsen Huub R?ttgering Tilman Spohn Susanne Vennerstrom Graham Woan Philippe Zarka 《Experimental Astronomy》2012,33(2-3):529-585
Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of the Moon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded the primary differentiation and evolution of the Moon, it can be continuously monitored from the Earth–Moon L2 Lagrange point, and there is a complete lack of reflected solar illumination from the Earth. Farside Explorer will exploit these properties and make the first radio-astronomy measurements from the most radio-quiet region of near-Earth space, determine the internal structure and thermal evolution of the Moon, from crust to core, and quantify impact hazards in near-Earth space by the measurement of flashes generated by impact events. The Farside Explorer flight system includes two identical solar-powered landers and a science/telecommunications relay satellite to be placed in a halo orbit about the Earth–Moon L2 Lagrange point. One lander would explore the largest and oldest recognized impact basin in the Solar System— the South Pole–Aitken basin—and the other would investigate the primordial highlands crust. Radio astronomy, geophysical, and geochemical instruments would be deployed on the surface, and the relay satellite would continuously monitor the surface for impact events. 相似文献
48.
Marilyn N. Raphael 《自然地理学》2013,34(6):516-528
The size and geographical distribution of the zonal eddy sensible heat flux and its divergence in the Northern Hemisphere winter are examined. Special attention is paid to the zonal eddy contribution to the total heat transport and the relationship between the zonal and meridional heat transport. The heat fluxes are calculated using 700mb air temperatures and geostrophic winds spanning the period 1947–1987. The zonal fluxes are much larger than the meridional fluxes, particularly in the regions of strongest flux. The sign and strength of the zonal flux are largely controlled by the direction and strength of the meridional transport. Zonal eddy transfer appears to be as important a source of energy as the meridional eddy transfer, particularly over North America and Siberia. Changes in atmospheric circulation strengths may be interpreted in terms of energy flux divergence to establish links with temperature changes. [Key words: sensible heat flux, zonal heat flux, meridional heat flux, energy flux divergence]. 相似文献
49.
Mapping gamma radiation and its uncertainty from weathering products in a Tasmanian landscape with a proximal sensor and random forest kriging 下载免费PDF全文
The radionuclides of potassium (40 K), uranium (238U) and thorium (232Th) emit from the land surface gamma radiation that is characteristic of the underlying rocks and the distribution of their weathering products in the landscape. We measured the radiation along widely separated transects using a mobile proximal sensor over a 10 000‐ha region of Tasmania. We supplemented the transect data with information from soil and geological maps and dense data from LandSat and SPOT imagery, a digital elevation model and terrain attributes on a grid at 30‐m intervals so as to map the radionuclides. We used a sequence of steps, starting with a spatial bootstrap and random forests to predict emissions across the study area and at sampling points excluded from the bootstrap samples. The predictions at the sampling points were compared with the observed values to obtain residuals, which were then used to krige them at all points on the 30 m grid. We combined the random forest and kriging predictions on the 30‐m grid to obtain our random forest kriging predictions. Repeating the procedure 100 times provided confidence limits on our results and predictions. The resulting maps of the radionuclides accord well with what we know of the soil, lithology and topography of the region from other sources. Alluvial deposits with large amounts of potassium extend from the foot slopes of the Great Western Tiers and along the flood plains of the Meander River, providing evidence of previous widespread weathering and deposition of the material. The fertile Red Ferrosols (roughly equivalent to Ferralic Nitisols in the World reference base (WRB) classification) on the extensive Tertiary basalt plateau emit little gamma radiation as a result of deep weathering and of potassium movement and accumulation down its talus slopes. The maps show the complexity of the region in terms of soil, lithology and terrain, and they show the merits of gamma radiometry for mapping and understanding the distribution of materials in such regions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
50.
Development of a national VNIR soil-spectral library for soil classification and prediction of organic matter concentrations 总被引:4,自引:0,他引:4
SHI Zhou WANG QianLong PENG Jie JI WenJun LIU HuanJun LI Xi Raphael A VISCARRA ROSSEL 《中国科学:地球科学(英文版)》2014,57(7):1671-1680
Soil visible-near infrared diffuse reflectance spectroscopy(vis-NIR DRS)has become an important area of research in the fields of remote and proximal soil sensing.The technique is considered to be particularly useful for acquiring data for soil digital mapping,precision agriculture and soil survey.In this study,1581 soil samples were collected from 14 provinces in China,including Tibet,Xinjiang,Heilongjiang,and Hainan.The samples represent 16 soil groups of the Genetic Soil Classification of China.After air-drying and sieving,the diffuse reflectance spectra of the samples were measured under laboratory conditions in the range between 350 and 2500 nm using a portable vis-NIR spectrometer.All the soil spectra were smoothed using the Savitzky-Golay method with first derivatives before performing multivariate data analyses.The spectra were compressed using principal components analysis and the fuzzy k-means method was used to calculate the optimal soil spectral classification.The scores of the principal component analyses were classified into five clusters that describe the mineral and organic composition of the soils.The results on the classification of the spectra are comparable to the results of other similar research.Spectroscopic predictions of soil organic matter concentrations used a combination of the soil spectral classification with multivariate calibration using partial least squares regression(PLSR).This combination significantly improved the predictions of soil organic matter(R2=0.899;RPD=3.158)compared with using PLSR alone(R2=0.697;RPD=1.817). 相似文献