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91.
Emil Riggenbach Dr.phil. 《Aquatic Sciences - Research Across Boundaries》1924,3(1-2):87-116
Ohne Zusammenfassung 相似文献
92.
Stein Rune Karlsen Anne Tolvanen Eero Kubin Jarmo Poikolainen Kjell Arild Høgda Bernt Johansen Fiona S. Danks Paul Aspholm Frans Emil Wielgolaski Olga Makarova 《International Journal of Applied Earth Observation and Geoinformation》2008
Northern Fennoscandia is an ecologically heterogeneous region in the arctic/alpine-boreal transition area. Phenology data on birch from 13 stations and 16-day MODIS-NDVI composite satellite data with 250 m resolution for the period 2000 to 2006 were used to map the growing season. A new combined pixel-specific NDVI threshold and decision rule-based mapping method was developed to determine the onset and end of the growing season. A moderately high correlation was found between NDVI data and birch phenology data. The earliest onset of the growing season is found in the narrow strip of lowland between the mountains and the sea along the coast of northern Norway. The onset follows a clear gradient from lowland to mountain corresponding to the decreasing temperature gradient. In autumn, the yellowing of the vegetation shows a more heterogeneous pattern. The length of the growing season is between 100 and 130 days in 55% of the study area. 相似文献
93.
Vojtěch Letfus Emil M. Apostolov Jan Klimeš Reviewer J. Laštovička 《Studia Geophysica et Geodaetica》1982,26(3):281-294
a auauu m ma ¶rt;a a a amua aama m¶rt;, m n¶rt;m anau umu, u m nu¶rt;um ¶rt;a a nu mau am . m¶rt; nu a¶rt;u amu a ¶rt; mau aauu nu (nu, au, 27 , u uma, au, 29 ) mu 1967–1970
. m¶rt; n¶rt;mam ¶rt;a u, u aaua mam, m n¶rt;nmu a¶rt; m¶rt;am anau umua u am, u m umuu a m mnua. ¶rt;u u mam aaua m ma nuau ¶rt;u n u ma ¶rt;a a. anau um a u mau mu¶rt;a ¶rt; u u -ana¶rt;u anauu. au ¶rt;a u n¶rt;¶rt;uam aau m ¶rt;a u a¶rt;a a a amua a¶rt; n [15]. m, m mu¶rt;a um m m aa m anmauu ¶rt;u a¶rt;u, m a auum u ¶rt; anmau a¶rt;u u mau ¶rt;m (uu m m u), u ma m um a¶rt; m auauu anauu amu nu¶rt;u a¶rt;am ¶rt; ¶rt;a a. 相似文献
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Ohne ZusammenfassungHerrn Professor Dr.O. H. Erdmannsdörffer zur Vollendung des 75. Lebensjahres gewidmet. 相似文献
97.
The paleo-evolution of the Black Sea level during the Lateglacial–Holocene transition is still unclear, which motivates us
to provide new estimates for that period based on the analysis of water budget. Hydrological conditions in the Black Sea catchment
area are reconstructed here using water balance equation, available data, and constraints based on simple theory relating
the runoff ratio with climatic characteristics. In order to estimate the impact of the aridity of climate we consider two
alternative scenarios: (1) climate change under constant in time gradient in precipitation and evaporation over land and sea,
and (2) climate change accounting for changes in the horizontal distribution of precipitation and evaporation. Hydrological
data are compiled from available present-day data and paleo-observations. A number of sensitivity experiments is carried out
revealing that the hydrological conditions in the Black Sea watershed should have evolved towards a very arid climate (similar
to the present-day climate in the Caspian Sea area) in order to initiate a drop of sea level of ∼100 m below the sill depth
of the Bosporus Straits, as speculated in some recent research. Estimates of sea level changes reveal a qualitative agreement
with the coast-line evolution inferred from paleo-observations. The Younger Dryas draw down of the Black Sea starts at about
13.3 to 13 kyr BP, with a maximum low-stand of 104 m at 11.5 kyr BP. In an arid climate scenario the sea level reaches the
outlet at about 8.8 to 7.4 kyr BP. Approximately at that time, Mediterranean sea level was about 10 m higher, making flooding
events of the Black Sea possible. However, the nature and exact timing of the Holocene reconnection depends also on other
(not well known) factors; one of them is the Bosporus sill depth, motivating further research in this field. Estimates of
the water transport through the Bosporus Straits are also provided for the time of Lateglacial–Holocene transition. 相似文献
98.
The delineation of wellhead protection areas (WHPAs) under uncertainty is still a challenge for heterogeneous porous media. For granular media, one option is to combine particle tracking (PT) with the Monte Carlo approach (PT‐MC) to account for geologic uncertainties. Fractured porous media, however, require certain restrictive assumptions under this approach. An alternative for all types of media is the capture probability (CP) approach, which is based on the solution of the standard advection‐dispersion equation in a backward mode, making use of the analogy between forward and backward transport processes. Within this context, we review the current controversy about the correct form of the conceptual model for transport, finding that the advection‐diffusion model, which represents the diffusive interchange between streamtubes with differing velocities, is more physically realistic than the conventional advection‐dispersion model. For mildly to moderately heterogeneous materials, stochastic theories and simulation experiments show that this process converges at the field scale to an effective advection‐dispersion process that can be simulated with conventional transport models using appropriate macrodispersivity values. For highly heterogeneous materials, stochastic theories do not yet exist but there is no reason why the process should not converge naturally as well. Macrodispersivities appear to be formation‐specific. The advection‐dispersion model can be used for capture zone delineation in heterogeneous granular media. For fractured porous systems, hybrid equivalent porous medium and discrete fracture network or CP‐based approaches may have potential. In general, capture zones delineated by PT without MC will always be too small and should not be used as a basis for land‐use decisions. 相似文献
99.
Ocean Dynamics - The interactions between barotropic tides and mesoscale processes were studied using the results of a numerical model in which tidal forcing was turned on and off. The research... 相似文献
100.