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181.
Silvia Kloster Frank Dentener Johann Feichter Frank Raes Ulrike Lohmann Erich Roeckner Irene Fischer-Bruns 《Climate Dynamics》2010,34(7-8):1177-1194
We use the global atmospheric GCM aerosol model ECHAM5-HAM to asses possible impacts of future air pollution mitigation strategies on climate. Air quality control strategies focus on the reduction of aerosol emissions. Here we investigate the extreme case of a maximum feasible end-of-pipe abatement of aerosols in the near term future (2030) in combination with increasing greenhouse gas (GHG) concentrations. The temperature response of increasing GHG concentrations and reduced aerosol emissions leads to a global annual mean equilibrium temperature response of 2.18 K. When aerosols are maximally abated only in the Industry and Powerplant sector, while other sectors stay with currently enforced regulations, the temperature response is 1.89 K. A maximum feasible abatement applied in the Domestic and Transport sector, while other sectors remain with the current legislation, leads to a temperature response of 1.39 K. Increasing GHG concentrations alone lead to a temperature response of 1.20 K. We also simulate 2–5% increases in global mean precipitation among all scenarios considered, and the hydrological sensitivity is found to be significantly higher for aerosols than for GHGs. Our study, thus highlights the huge potential impact of future air pollution mitigation strategies on climate and supports the need for urgent GHG emission reductions. GHG and aerosol forcings are not independent as both affect and are influenced by changes in the hydrological cycle. However, within the given range of changes in aerosol emissions and GHG concentrations considered in this study, the climate response towards increasing GHG concentrations and decreasing aerosols emissions is additive. 相似文献
182.
Raspini Federico Bardi Federica Bianchini Silvia Ciampalini Andrea Del Ventisette Chiara Farina Paolo Ferrigno Federica Solari Lorenzo Casagli Nicola 《Natural Hazards》2017,86(1):327-351
Natural Hazards - Landslides are common phenomena that occur worldwide and are a main cause of loss of life and damage to property. The hazards associated with landslides are a challenging concern... 相似文献
183.
Silvia Albarracín Javier Alcántara-Carrió Andrés Barranco María José Sánchez García Ángela Fontán Bouzas Jorge Rey Salgado 《Geo-Marine Letters》2013,33(2-3):217-223
The focus of this study is the analysis of coastal sand barriers and associated coastal lagoons on the inner continental shelf of the Gulf of Valencia (western Mediterranean), based on two W–E seismic profiles recorded seaward of the Albufera de Valencia coastal lagoon. Seismic facies identified include a number of coastal sand barriers with landward lagoons draped by contemporary continental shelf deposits. The barrier systems have been grouped into two sedimentary systems tracts, the older one corresponding to a prograding/aggrading highstand systems tract involving at least four paleo-coastal sand barrier/lagoon systems, followed landward by a transgressive systems tract comprising three such systems. All the systems have been allocated a Tyrrhenian age, the formation of individual barrier systems having been associated with successive sea-level stillstands, and their present-day position being explained by the very high regional subsidence rate. In summary, this study demonstrates that the Quaternary stratigraphic record of the Gulf of Valencia inner continental shelf is composed of littoral sand facies, in particular coastal sand barrier and lagoon deposits. These findings are in agreement with corresponding observations on other continental shelves of the western Mediterranean, showing that the formation of coastal sand barriers was a characteristic feature of this region during the Quaternary. 相似文献
184.
Araucaria antarctica Césari et al. is an illegitimate name because it is a later homonym of Araucaria antarctica Gee (fossil Araucariaceae). Hence, a new specific epithet, fibrosa, is proposed to accommodate the species described more recently. 相似文献
185.
A comparison of selected global disaster risk assessment results 总被引:1,自引:0,他引:1
We compare country risk rankings derived from two recently published global disaster risk analyses. One set of country rankings
is based on the Disaster Risk Index (DRI) developed by the United Nations Environment Program (UNEP) Division of Early Warning
and Assessment Global Resource Information Database project under a contract to the United Nations Development Program (UNDP).
The other is based on an index of disaster mortality risk developed by the Global Natural Disaster Risk Hotspots project implemented
by Columbia University, the World Bank and associated partners. We convert data from these sources into two comparable indexes
of disaster mortality risk and rank countries according to the resulting values for a set of natural hazards common to both
studies. The country rankings are moderately correlated, ranging from .41 to .56 for individual hazards to .31 for multi-hazard
mortality risks. We identify the top 25 countries according to the mortality risk values we recomputed from each study’s results
to show the degree to which countries are highly ranked in common. The numbers of countries common to both lists for individual
hazards range from 7 to 16 out of 25. The correspondence among the top 25 ranked countries is lowest for earthquakes and floods.
Only 6 out of 25 countries are common to both lists in the multi-hazard case. We suggest that while the convergence in the
results for some hazards is encouraging, more work is needed to improve data and methods, particularly with respect to assessing
the role of vulnerability in the creation of risk and the calculation of multi-hazard risks.
The views expressed are the authors’ and do not necessarily reflect those of SM2 Consulting Multi-Hazards and Risk Holistic
Solutions or the United Nations Development Program. 相似文献
186.
Performing comprehensive laboratory test programs to estimate rockfill strength for rockfill dam projects is a lengthy and
onerous task because of the large sample-size. Accordingly, it has become a common practice to carry out limited experimental
investigation, and extrapolate the results to the expected conditions in actual embankments. A number of investigators have
established a function of the type τ = ασβ, where τ and σ are the shear and normal stresses, respectively, and the constants α and β, which result from a fitting procedure,
have no physical meaning. Results of laboratory tests on a variety of rockfills have shown that in addition to effective confining
stresses the relative density, uniformity coefficient, maximum particle size and particle-breaking load influence rockfill
strength. Thus these parameters must be included in any function for computing rockfill strength. Other parameters, whose
influence is understood partially, are not included here. Given the non linear-multidimensional nature of the problem, in
this paper a neuronal procedure is developed. This approach takes into account the influence of each of the parameters mentioned
before. The network used in this article was defined after comparing the results obtained with a variety of algorithms. After
several attempts, the Cascade Correlation Network (CCN) was found to yield most accurate strength predictions. 相似文献
187.
Luca Piciullo Stefano Luigi Gariano Massimo Melillo Maria Teresa Brunetti Silvia Peruccacci Fausto Guzzetti Michele Calvello 《Landslides》2017,14(3):995-1008
A process chain for the definition and the performance assessment of an operational regional warning model for rainfall-induced landslides, based on rainfall thresholds, is proposed and tested in a landslide-prone area in the Campania region, southern Italy. A database of 96 shallow landslides triggered by rainfall in the period 2003–2010 and rainfall data gathered from 58 rain gauges are used. First, a set of rainfall threshold equations are defined applying a well-known frequentist method to all the reconstructed rainfall conditions responsible for the documented landslides in the area of analysis. Several thresholds at different exceedance probabilities (percentiles) are evaluated, and nine different percentile combinations are selected for the activation of three warning levels. Subsequently, for each combination, the issuing of warning levels is computed by comparing, over time, the measured rainfall with the pre-defined warning level thresholds. Finally, the optimal percentile combination to be employed in the regional early warning system, i.e. the one providing the best model performance in terms of success and error indicators, is selected employing the “event, duration matrix, performance” (EDuMaP) method. 相似文献
188.
Nine of the cataloguedHii regions in the southern hemisphere have been selected for correlation with neutral hydrogen observed at the 21 cm line.The radiotelescope used for theHi line observations was the 30 m Carnegie telescope of the Instituto Argentino de Radioastronomía and the 56 channel, 10 KHz bandwidth receiver.The observational results are analyzed for eachHii region. They are compared with previous optical and radio results.For three of the nine observed regions it has been possible to find neutral hydrogen in absorption with similar velocities. In three cases absorption has been found but no component at theHii region velocity is seen. Finally in three cases, it has not been possible to find any absorption at all.Member of the Carrera del Investigador Científico del Cosejo Nacional de Investigaciones Científicas y Técnicas. 相似文献
189.
The 1976 Friuli seismic sequence is known for itscomplexity, with several unusually large aftershocksoccurring in the epicentral area. The source region, where the northeastern part of the Alpine chain meetsthe northern Dinaric chain, is characterized by a complexcompressional tectonic regime. Previous studies have not clearly identified which of the two main tectonic systems was activated, in part due to the limited precision of derived earthquake parameters, such as hypocentral coordinates and focal mechanisms. We review the locations for the 10 largest events of the sequence, including theSeptember 16, 1977 and April 18, 1979 earthquakes andwe compute their centroid moment tensors. Source parameters are calculated using intermediate period surfacewaves and the modification of the Harvard centroid-moment tensoralgorithm proposed by Arvidsson and Ekström (1998). A summary of all available geological, geodetic and seismological data show that most of the earthquakes may be associated with the Periadriatic overthrust and other related thrust faults. Based on their locations and focal mechanisms only two ofthe early aftershocks (May 7, 1976 and May 9, 1976) appear instead to have occurred on Dinaric structures. 相似文献
190.
Bhabagrahi Sahoo Muthiah Perumal Tommaso Moramarco Silvia Barbetta Soumyaranjan Sahoo 《水文科学杂志》2020,65(3):335-347
ABSTRACTStream gauge-based information is the foundation for many hydrological applications in a river basin including the aquatic-habitat conservation. A simple two-parameter model for routing streamflow depth (alternatively, stream–stage) hydrographs and estimating corresponding discharge hydrographs in river channels is proposed using the multilinear approach, based on Nash-type discrete-cascade model. The applicability of this model is investigated by extending its framework to the realm of compound cross-section trapezoidal channels for both in-bank and overbank flows by using 20 flood events of the Tiber River in the Umbria region of Central Italy, and subsequently comparing the simulated results with the corresponding simulations of the HEC-RAS (Hydrologic Engineering Center – River Analysis System) hydrodynamic model and observed flow depth hydrographs. The field application, comparative study, and uncertainty and sensitivity analysis of the results demonstrate that the proposed multilinear discrete Nash-cascade stage-hydrograph (MDNS) routing model has the potential for routing floods in real-world rivers and canal irrigation systems, especially in operational mode. 相似文献