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911.
Tim J. Smyth Peter I. Miller Steve B. Groom Samantha J. Lavender 《Progress in Oceanography》2001,51(2-4)
Satellite derived sea surface temperature (SST) and chlorophyll data are used to characterise the period of upwelling during a cruise on which two Lagrangian drift experiments were conducted off the Iberian Atlantic coast in August 1998. During the cruise there was a prolonged period of equator-ward winds which favour upwelling; three distinct maxima were observed in the meteorological data interspersed with periods of relaxation. The SST and chlorophyll imagery show upwelling to be active with distinct offshore filaments that are cooler and of higher chlorophyll concentration than the surrounding oceanic water; these filaments represent an important cross-shelf transport mechanism. A front detection methodology has been applied to satellite images and suggests that these filaments are distinct, long-lived features, characterised by enhanced primary production. 相似文献
912.
Michael R. Miller David E. Hinton James J. Blair John J. Stegeman 《Marine environmental research》1988,24(1-4)
Monoclonal antibody directed against a major β-naphthoflavone (BNF)-induced form of teleost cytochrome P-450, P-450E (equivalent to P-450c in rat) was used to immunolocalize this enzyme in liver, gill and heart of scup and trout. Liver sections from both species showed P-450E in the cytoplasm of hepatocytes. No regional differences were observed which might indicate zonation of cytochrome P-450E within subpopulations of hepatocytes. Scup exocrine pancreatic cells were only weakly positive. In the gill of both fish, cytochrome P-450E was restricted to the endothelium (pillar cells) of secondary lamellae, where fluorescence appeared as a chain in longitudinal sections through lamellae and as star-shaped clusters in en face views. Sections of ventricular wall in both species revealed P-450E was restricted to endothelium at margins of muscle bands limiting heart ventricular lumen. Localization in the specific cells of these and other organs may be fundamentally important in understanding the role of cytochrome P-450E. 相似文献
913.
M. R. Miller R. M. Stanley P. G. Stansberry S. C. Stamm A. H. Stiller 《Marine environmental research》1996,42(1-4)
The objective of these studies was to characterize hepatic Cyp1A induction by complex carbonaceous pitches both in Japanese medaka exposed via aquarium water and in cultured fish liver cells. Carbonaceous pitches were extracted with DMSO and added to aquaria water of medaka or to cultured medaka or trout liver cells, and CyplA induction was assessed by EROD assay. When medaka were exposed to different carbonaceous pitches, EROD activity was induced to different extents, and increased EROD induction was associated with increasing temperature of hydrogenation. EROD induction in cultured fish liver cells was somewhat less sensitive than that observed in vivo. These studies indicate CyplA induction in medaka can be used to detect compounds, such as polyaromatic hydrocarbons, in complex samples and could be used as a biomarker for the presence of these compounds in the environment. 相似文献
914.
The method of empirical orthogonal function (EOF) or principal component analysis (PCA) was used to investigate the spatial and temporal variability of shoreline data sets from Duck, North Carolina, the Gold Coast, Australia, and the United States Pacific Northwest. In the present work, an attempt is made to relate the individual modes of shoreline variability identified by the EOF analyses to select parameterizations of the nearshore environment. The parameters considered include the wave energy (E), the cross-shore and longshore wave energy fluxes (Fx and Fy), the wave steepness (Ho/Lo), the non-dimensional fall velocity parameter (Ω), the profile parameter (P), the surf-similarity parameter (ζ), and a surfzone Froude number (Fr). Correlation analyses were used to evaluate the linear relationship between each of these parameters and the temporal eigenfunctions, ck(t), associated with individual modes of shoreline change. Typically, strong correlations were observed between longshore uniform modes and the monthly means of several of the nearshore parameters. 相似文献
915.
916.
The present analysis confirms the contention that the majority of Jupiter's decametric radio emissions occur when Io is above the northern magnetic hemisphere of Jupiter. However, a substantial portion of the non-Io-related component of source A was found to occur when Io was above southern magnetic latitudes of Jupiter. 相似文献
917.
Benford’s Law gives the expected frequencies of the digits in tabulated data and asserts that the lower digits (1, 2, and
3) are expected to occur more frequently than the higher digits. This study tested whether the law applied to two large earth
science data sets. The first test analyzed streamflow statistics and the finding was a close conformity to Benford’s Law.
The second test analyzed the sizes of lakes and wetlands, and the finding was that the data did not conform to Benford’s Law.
Further analysis showed that the lake and wetland data followed a power law. The expected digit frequencies for data following
a power law were derived, and the lake data had a close fit to these expected digit frequencies.
The use of Benford’s Law could serve as a quality check for streamflow data subsets, perhaps related to time or geographical
area. Also, with the importance of lakes as essential components of the water cycle, either Benford’s Law or the expected
digit frequencies of data following a power law could be used as an authenticity and validity check on future databases dealing
with water bodies. We give several applications and avenues for future research, including an assessment of whether the digit
frequencies of data could be used to derive the power law exponent, and whether the digit frequencies could be used to verify
the range over which a power law applies. Our results indicate that data related to water bodies should conform to Benford’s
Law and that nonconformity could be indicators of (a) an incomplete data set, (b) the sample not being representative of the
population, (c) excessive rounding of the data, (d) data errors, inconsistencies, or anomalies, and/or (e) conformity to a
power law with a large exponent. 相似文献
918.
E. N. Kadygrov A. V. Koldaev E. A. Miller V. V. Sokolov M. N. Khaikin 《Russian Meteorology and Hydrology》2007,32(2):110-118
Results of the study of the urban heat island over Nizhni Novgorod on the basis of data from mobile and stationary microwave temperature profilers are presented. The stationary temperature profiler MTP-5 was installed in the city center. The profiler provides continuous temperature measurements in the altitude range from 0 to 600 m with accuracy 0.5°C and with the cycle of measurement 5 min. The mobile version of the MTP-5 instrument (MMTP-5) provides measurements at 17 points including 11 inside the city and 6 in the suburb. Measurements were taken under anticyclone conditions mostly at night and in the morning on August 6 and 7, September 1, and October 16–18, 2004. 相似文献
919.
J. Hansen M. Sato R. Ruedy P. Kharecha A. Lacis R. Miller L. Nazarenko K. Lo G. A. Schmidt G. Russell I. Aleinov S. Bauer E. Baum B. Cairns V. Canuto M. Chandler Y. Cheng A. Cohen A. Del Genio G. Faluvegi E. Fleming A. Friend T. Hall C. Jackman J. Jonas M. Kelley N. Y. Kiang D. Koch G. Labow J. Lerner S. Menon T. Novakov V. Oinas Ja. Perlwitz Ju. Perlwitz D. Rind A. Romanou R. Schmunk D. Shindell P. Stone S. Sun D. Streets N. Tausnev D. Thresher N. Unger M. Yao S. Zhang 《Climate Dynamics》2007,29(7-8):661-696
We carry out climate simulations for 1880–2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble
of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together.
We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among
model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all
forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are
notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations
of future climate change. By using a fixed well-documented model and accurately defining the 1880–2003 forcings, we aim to
provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested.
Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea
ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in
the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
920.
Predictive vegetation modeling is defined as predicting the distribution of vegetation across a landscape based upon its relationship with environmental factors. These models generally ignore or attempt to remove spatial dependence in the data. When explicitly included in the model, spatial dependence can increase model accuracy. We develop presence/absence models for 11 vegetation alliances in the Mojave Desert with classification trees and generalized linear models, and use geostatistical interpolation to calculate spatial dependence terms used in the models. Results were mixed across models and methods, but in general, the spatial dependence terms more consistently increased model accuracy for widespread alliances. GLMs had higher accuracy in general. 相似文献