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111.
A rapid approach to estimate the rockfall energies and distances at the base of rock cliffs 总被引:1,自引:0,他引:1
Federica Ferrari Klaus Thoeni Anna Giacomini Cedric Lambert 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2016,10(3):179-199
This paper presents a new methodology for estimating the expected energies and first impact distances at the base of a rock cliff, subject to the geometry and properties of the cliff and the representative block being known. The method is based on a sensitivity analysis, conducted by means of kinematic simulations and carried out for a large range of input parameters and their combinations, taking into account the uncertainty associated with their estimate. The proposed approach is validated by comparing predictions to experimental data and shows great potential for a quick qualitative hazard assessment. 相似文献
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Linda J. Spilker Stuart H. Pilorz John C. Pearl Shawn M. Brooks Scott G. Edgington F. Michael Flasar Cedric Leyrat 《Planetary and Space Science》2006,54(12):1167-1176
In late 2004 and 2005 the Cassini composite infrared spectrometer (CIRS) obtained spatially resolved thermal infrared radial scans of Saturn's main rings (A, B and C, and Cassini Division) that show ring temperatures decreasing with increasing solar phase angle, α, on both the lit and unlit faces of the ring plane. These temperature differences suggest that Saturn's main rings include a population of ring particles that spin slowly, with a spin period greater than 3.6 h, given their low thermal inertia. The A ring shows the smallest temperature variation with α, and this variation decreases with distance from the planet. This suggests an increasing number of smaller, and/or more rapidly rotating ring particles with more uniform temperatures, resulting perhaps from stirring by the density waves in the outer A ring and/or self-gravity wakes.The temperatures of the A and B rings are correlated with their optical depth, τ, when viewed from the lit face, and anti-correlated when viewed from the unlit face. On the unlit face of the B ring, not only do the lowest temperatures correlate with the largest τ, these temperatures are also the same at both low and high α, suggesting that little sunlight is penetrating these regions.The temperature differential from the lit to the unlit side of the rings is a strong, nearly linear, function of optical depth. This is consistent with the expectation that little sunlight penetrates to the dark side of the densest rings, but also suggests that little vertical mixing of ring particles is taking place in the A and B rings. 相似文献
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Seong-Hoon Cho Dayton M. Lambert Seung Gyu Kim Roland K. Roberts William M. Park 《Journal of Geographical Systems》2011,13(4):393-414
This research uses a sequence of hedonic spatial regressions for a metropolitan housing market in the Southeastern United
States to explore a new procedure that establishes the relationship between the value attributable to open space and distance
from housing locations (a “distance-decay function”) within a given community. A distance-decay function allows identification
of the range of distance over which open space affects housing values and the estimation of a proxy for the value added to
nearby houses resulting from hypothetical open space preservation. Ex post analyses of the open-space regression coefficients suggest marginal implicit price functions for three types of open space
that decay as open space area increases with respect to house location. After controlling for other factors in the spatial
hedonic model, simple distance-decay functional relationships were established between the implicit prices of developed open
space, forest-land open space, and agriculture-wetland open space and the buffer radius of the open-space areas surrounding
a given housing location. The proposed method may be useful for identifying the range over which preferences for different
types of open space are exhibited. 相似文献
120.
The use of the possibility theory to investigate the epistemic uncertainties within scenario-based earthquake risk assessments 总被引:1,自引:0,他引:1
This paper presents a methodology to represent and propagate epistemic uncertainties within a scenario-based earthquake risk
model. Unlike randomness, epistemic uncertainty stems from incomplete, vague or imprecise information. This source of uncertainties
still requires the development of adequate tools in seismic risk analysis. We propose to use the possibility theory to represent
three types of epistemic uncertainties, namely imprecision, model uncertainty and vagueness due to qualitative information.
For illustration, an earthquake risk assessment for the city of Lourdes (Southern France) using this approach is presented.
Once adequately represented, uncertainties are propagated and they result in a family of probabilistic damage curves. The
latter is synthesized, using the concept of fuzzy random variables, by means of indicators bounding the true probability to
exceed a given damage grade. The gap between the pair of probabilistic indicators reflects the imprecise character of uncertainty
related to the model, thus picturing the extent of what is ignored and can be used in risk management. 相似文献