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131.
Cristiana Guerranti Stefania Ancora Nicola Bianchi Guido Perra Emiliano Leonida Fanello Simonetta Corsolini Maria Cristina Fossi Silvano Ettore Focardi 《Marine pollution bulletin》2013
Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found. 相似文献
132.
133.
Fast switch from extensional exhumation to thrusting of the Ronda Peridotites (South Spain)
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Gianluca Frasca Frédéric Gueydan Marc Poujol Jean‐Pierre Brun Fleurice Parat Patrick Monié Alexandre Pichat Sophie Mazier 《地学学报》2017,29(2):117-126
The Alboran Domain, situated at the western end of the Mediterranean subduction system, is characterized by the Ronda Peridotites, one of the world's largest exposures of sub‐continental mantle. Using U–Pb (LA‐ICP‐MS) and Ar–Ar dating, we precisely dated two tectonic events associated with the Tertiary exhumation of the Ronda Peridotites. First, shearing along the Crust–Mantle Extensional Shear Zone caused, at ca. 22.5 Ma, mantle exhumation, local partial melting in the deep crust and coeval cooling in the upper crust. Second, the Ronda Peridotites Thrust triggered the final emplacement of the peridotites onto the continental crust at c. 21 Ma, as testified by granitic intrusions in the thrust hangingwall. The tectonic evolution of the western Alboran Domain is therefore characterized by a fast switch from continental lithospheric extension in a backarc setting, with sub‐continental mantle exhumation, to a rift inversion by thrusting driven by shortening of the upper plate. 相似文献
134.
Gianluca Sottili Danilo M. Palladino Mario Gaeta Matteo Masotta 《Bulletin of Volcanology》2012,74(1):163-186
Maar volcanoes represent a common volcano type which is produced by the explosive interaction of magma with external water.
Here, we provide information on a number of maars in the ultrapotassic Sabatini Volcanic District (SVD, Roman Province) as
young as ∼90 ka. The SVD maars are characterised in terms of crater and ejecta ring morphologies, eruptive successions and
magma compositions, in light of the local substrate settings, with the aim of assessing magma–water interaction conditions,
eruption energetics and genetic mechanisms. Feeder magmas spanned the whole SVD differentiation trend from trachybasalts–shoshonites
to phonolites. From the ejected lithic fragments from aquifer rocks, the range of depth of magma–water explosive interaction
is estimated to have been mostly at ∼400–600 m below ground level, with a single occurrence of surficial interaction in palustrine–lacustrine
environment. In particular, the interaction with external water may have triggered the explosive behaviour of poorly differentiated
magmas, whereas it may have acted only as a late controlling factor of the degree of fragmentation and eruption style for
the most differentiated magma batches during low-flux ascent in an incipiently fragmented state. Crater sizes, ejecta volumes
and ballistic data allow a reconstruction of the energy budget of SVD maar-forming eruptions. Erupted tephra volumes from
either monogenetic or polygenetic maars ranged 0.004–0.07 km3 during individual maar-forming eruptions, with corresponding total magma thermal energies of 8 × 1015–4 × 1017 J. Based on energy partitioning and volume balance of erupted magmas and lithic fractions vs. crater holes, we consider the
different contributions of explosive excavation of the substrate vs. subsidence in forming the SVD maar craters. Following
available models based on crater sizes, highly variable fractions (5–50%) of the magma thermal energies would have been required
for crater excavation. It appears that subsidence may have played a major role in some SVD maars characterised by low lithic
contents, whilst substrate excavation became increasingly significant with increasing degrees of aquifer fragmentation. 相似文献
135.
Simona Scollo Antonella Boselli Mauro Coltelli Giuseppe Leto Gianluca Pisani Nicola Spinelli Xuan Wang 《Bulletin of Volcanology》2012,74(10):2383-2395
In this paper, we use data obtained from LiDAR measurements during an ash emission event on 15 November 2010 at Mt. Etna, in Italy, in order to evaluate the spatial distribution of volcanic ash in the atmosphere. A scanning LiDAR system, located at 7?km distance from the summit craters, was directed toward the volcanic vents and moved in azimuth and elevation to analyse different volcanic plume sections. During the measurements, ash emission from the North East Crater and high degassing from the Bocca Nuova Crater were clearly visible. From our analysis we were able to: (1) evaluate the region affected by the volcanic plume presence; (2) distinguish volcanic plumes containing spherical aerosols from those having non-spherical ones; and (3) estimate the frequency of volcanic ash emissions. Moreover, the spatial distribution of ash mass concentration was evaluated with an uncertainty of about 50?%. We found that, even during ash emission episodes characterised by low intensity like the 15 November 2010 event, the region in proximity of the summit craters should be avoided by air traffic operations, the ash concentration being greater than 4?×?10?3?g/m3. The use of a scanning permanent LiDAR station may usefully monitor the volcanic activity and help to drastically reduce the risks to aviation operations during the frequent Etna eruptions. 相似文献
136.
Gaetano Zonno Roberto Basili Fabrizio Meroni Gemma Musacchio P. Martin Mai Gianluca Valensise 《Bulletin of Earthquake Engineering》2012,10(4):1075-1107
We present a strategy for obtaining fault-based maximum observable shaking (MOS) maps, which represent an innovative concept for assessing deterministic seismic ground motion at a regional scale. Our approach uses the fault sources supplied for Italy by the Database of Individual Seismogenic Sources, and particularly by its composite seismogenic sources (CSS), a spatially continuous simplified 3-D representation of a fault system. For each CSS, we consider the associated Typical Fault, i.e., the portion of the corresponding CSS that can generate the maximum credible earthquake. We then compute the high-frequency (1–50?Hz) ground shaking for a rupture model derived from its associated maximum credible earthquake. As the Typical Fault floats within its CSS to occupy all possible positions of the rupture, the high-frequency shaking is updated in the area surrounding the fault, and the maximum from that scenario is extracted and displayed on a map. The final high-frequency MOS map of Italy is then obtained by merging 8,859 individual scenario-simulations, from which the ground shaking parameters have been extracted. To explore the internal consistency of our calculations and validate the results of the procedure we compare our results (1) with predictions based on the Next Generation Attenuation ground-motion equations for an earthquake of Mw 7.1, (2) with the predictions of the official Italian seismic hazard map, and (3) with macroseismic intensities included in the DBMI04 Italian database. We then examine the uncertainties and analyse the variability of ground motion for different fault geometries and slip distributions. 相似文献
137.
S. Bianchi A. Corral F. Panessa X. Barcons G. Matt L. Bassani F. J. Carrera E. Jiménez-Bailón 《Monthly notices of the Royal Astronomical Society》2008,385(1):195-199
We report on simultaneous optical and X-ray observations of the Seyfert galaxy, NGC 3147. The XMM–Newton spectrum shows that the source is unabsorbed in the X-rays ( N H < 5 × 1020 cm−2 ) . On the other hand, no broad lines are present in the optical spectrum. The origin of this optical/X-rays misclassification (with respect to the Unification Model) cannot be attributed to variability, since the observations in the two bands are simultaneous. Moreover, a Compton-thick nature of the object can be rejected on the basis of the low-equivalent width of the iron Kα line (≃130 eV) and the large ratio between the 2–10 keV and the [O iii ] fluxes. It seems therefore inescapable to conclude that NGC 3147 intrinsically lacks the Broad-Line Region, making it the first 'true' type 2 Seyfert galaxy. 相似文献
138.
Maria A. Brovelli Marco Minghini Gianluca Giori Michele Beretta 《Transactions in GIS》2012,16(2):125-142
In the State Archive of Como, Northern Italy, about 15,000 historical maps belonging to different national cadastral productions are preserved. The Web C.A.R.T.E. project was started to enhance the accessibility of this valuable cartographic heritage using FOSS (Free and Open Source Software) technologies. The system, which implements specific web geoservices for cataloguing and visualization, should assist the State Archive of Como in the digital management of its cartographic resources and related information. After the high‐resolution digitization step, maps undergo a georeferencing operation. A special statistical procedure for choosing the best mathematical model was developed, verifying also strengths and weaknesses of georeferencing with a common free and Open Source GIS. Next, metadata consistent with current Italian standards were added to the georeferenced maps using an ad hoc localized version of GeoNetwork Opensource (recently provided as the official Italian version of the software). A dedicated WebGIS system was built for publishing the georeferenced cadastral maps. This system is capable of navigating large raster data in a georeferenced framework and easily retrieving their metadata. The WebGIS system for the State Archive of Como is an important contribution for the preservation of the original historical paper maps and also a great modernization and simplification of the end user's access to this archive. 相似文献
139.
Hydrogeochemical study in the Main Ethiopian Rift: new insights to the source and enrichment mechanism of fluoride 总被引:2,自引:0,他引:2
Tewodros Rango Gianluca Bianchini Luigi Beccaluva Tenalem Ayenew Nicolò Colombani 《Environmental Geology》2009,58(1):109-118
The central Main Ethiopian Rift suffers a severe water quality problem, characterized by an anomalously high fluoride (F)
content that causes an endemic fluorosis disease. The current study, conducted in the Ziway–Shala lakes basin, indicates that
the F content exceeds the permissible limit for drinking prescribed by the World Health Organization (WHO; 1.5 mg/l) in many
important wells (up to 20 mg/l), with even more extreme F concentration in hot springs and alkaline lakes (up to 97 and 384 mg/l
respectively). The groundwater and surface water from the highlands, typically characterized by low total dissolved solids
(TDS) and Ca (Mg)–HCO3 hydrochemical facies, do not show high F content. The subsequent interaction of these waters with the various rocks of the
rift valley induces a general increase of the TDS, and a variation of the chemical signature towards Na–HCO3 compositions, with a parallel enrichment of F. The interacting matrixes are mainly rhyolites consisting of volcanic glass
and only rare F-bearing accessory minerals (such as alkali amphibole). Comparing the abundance and the composition of the
glassy groundmass with other mineral phases, it appears that the former stores most of the total F budget. This glassy material
is extremely reactive, and its weathering products (i.e. fluvio/volcano-lacustrine sediments) further concentrate the fluoride.
The interaction of these “weathered/reworked” volcanic products with water and carbon dioxide at high pH causes the release
of fluoride into the interacting water. This mainly occurs by a process of base-exchange softening with the neo-formed clay
minerals (i.e. Ca–Mg uptake by the aquifer matrix, with release of Na into the groundwater). This is plausibly the main enrichment
mechanism that explains the high F content of the local groundwater, as evidenced by positive correlation between F, pH, and
Na, and inverse correlation between F and Ca (Mg). Saturation indices (SI) have been calculated (using PHREEQC-2) for the
different water groups, highlighting that the studied waters are undersaturated in fluorite. In these conditions, fluoride
cannot precipitate as CaF2, and so mobilizes freely without forming other complexes. These results have important implications for the development of
new exploitation strategies and accurate planning of new drilling sites.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
140.
Alessio Rovere Stefano Bellati Valeriano Parravicini Marco Firpo Carla Morri Carlo Nike Bianchi 《Estuaries and Coasts》2009,32(2):333-339
The existence of linkages between ecological and geomorphological processes and the influence of human activities both on
the biota and on geomorphology is well known for terrestrial environments, while it has been seldom reported for submerged
ones. A survey in the Noli-Bergeggi area (NW Mediterranean Sea) has been carried out to test the hypothesis that the harvesting
of Lithophaga lithophaga has an impact not only on the hammered rock, but also on the sediments at the cliff foot. Size and roundness of pebbles have
been measured at different stations and statistical analyses have been used to test the differences between impact and control
situations. Results show a dependence of the roundness of pebbles on the date mussel harvesting, indicating a decrease both
of the roundness index and of its variability at the cliff foot in impacted sites. Conclusions stress the biogeomorphological
nature of this activity, not limited to the present location. 相似文献