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581.
Jin Yaqiu 《Frontiers of Earth Science》2007,1(3):284-298
This paper briefly presents the research progress of the State Major Basic Research Project 2001CB309400, “Theory and Application
for Retrieval and Fusion of Spatial and Temporal Quantitative Information from Complex Natural Environment”. Based on the
rapid advancement of synthetic aperture radar (SAR) imagery technology, information theory of fully polarimetric scattering
and applications in polarimetric SAR remote sensing are developed. To promote the modeling of passive microwave remote sensing,
the vector (polarized) radiative transfer theory (VRT) of complex natural media such as inhomogeneous, multi-layered and 3-dimensional
VRT is developed. With these theoretical progresses, data validation and retrieval algorithms for some typical events and
characteristic parameters of earth terrain surfaces, atmosphere, and oceans from operational and experimental remote sensing
satellites are studied. Employing remote sensing, radiative transfer simulation, geographic information systems (GIS), land
hydrological process, and data assimilation, the Chinese land data assimilation system (CLDAS) is established. Towards the
future development of China’s microwave meteorological satellites, employing remote sensing data of currently available SSM/I
(special sensor microwave/imager), AMSU (advanced microwave sounding unit), MTI (microwave temperature imager), etc., with
ground-based measurements, several operational algorithms and databases for atmospheric precipitation, water vapor and liquid
water in clouds, and other hydrological/hydrological applications are developed. To advance China’s SAR and InSAR (interferometric
SAR) technologies, the image processing and analysis of ERS (European remote sensing), Radarsat SAR, and Chinese SAR, etc.,
the software platforms are accomplished. Based on the researches of multi-information fusion, some simulations, identification,
and information extractions of the targets from complex background clutter scenes are studied. Some experiments of radio wave
propagation in anomalous atmospheric status are also carried out.
Translated from Advances in Earth Science, 2007, 22(2): 111–125 [译自: 地球科学进展] 相似文献
582.
This article addresses a new reserve estimation method which uses fuzzy modeling algorithms and estimates the reserve parameters
based on spatial variability. The proposed fuzzy modeling approach has three stages: (1) Structure identification and preliminary
clustering, (2) Variogram analysis, and (3) Clustering based rule system. A new clustering index approach and a new spatial
measure function (point semimadogram) are proposed in the paper. The developed methodology uses spatial variability in each
step and takes the fuzzy rules from input-output data. The model has been tested using both simulated and real data sets.
The performance evaluation indicates that the new methodology can be applied in reserve estimation and similar modeling problems 相似文献
583.
584.
585.
准格尔丘陵沟壑区五分地沟流域土地覆盖分析 总被引:1,自引:0,他引:1
以准格尔丘陵沟壑区五分地沟流域为研究区,应用彩红外航片和IKONOS卫星影像,绘制了1987、2002年土地覆盖/植被类型图,并数字化基于地面土地利用调查绘制的1979年土地利用图.利用景观格局指数,评价了研究区土地覆盖/植被空间格局现状及土地覆盖类型动态变化;并以ETM 数据为信息源,绘制了2002年土地覆盖/植被类型图.研究表明:2002年研究区土地覆盖/植被呈现出一个耕地、草地、人工乔木林和人工灌木林以及种植稀疏灌木的草地高度镶嵌的景观格局特征;20年内土地覆盖类型发生了显著的变化,景观异质性增强.基于研究区景观的高度破碎化,绘制小流域精细尺度土地覆盖图,高空间分辨率遥感数据十分必要. 相似文献
586.
以新疆艾比湖地区为研究区,通过对现有荒漠化监测指标体系的归纳分析,界定了复合荒漠化概念.利用遥感影像数据提取研究区各类荒漠化的现状与动态变化信息.研究结果表明:单一主导因子荒漠化类型面积占荒漠化土地总面积的82.29%,复合荒漠化面积占17.71%.2002~2005年,艾比湖湖面面积缩小了322.5073 km2,相应的总体土地荒漠化面积增加了7.18%,复合荒漠化面积增加了133%.土地荒漠化的过程同时也发生了变化,风蚀、复合荒漠化增加而土地盐渍化减少,荒漠化程度加重,复合荒漠化类型增加并向其他土地类型扩展. 相似文献
587.
Geochemistry and spatial distribution of OIB and MORB in A’nyemaqen ophiolite zone: Evidence of Majixueshan ancient ridge-centered hotspot 总被引:2,自引:0,他引:2
The mafic volcanic association is made up of OIB, E-MORB and N-MORB in the A'nyemaqen Paleozoic ophiolites. Compared with the same type rocks in the world, the mafic rocks generally display lower Nb/U and Ce/Pb ratios and some have Nb depletion and Pb enrichment. The OIB are LREE-enriched with (La/Yb)N =5―20, N-MORB are LREE-depleted with (La/Yb)N = 0.41―0.5. The OIB are featured by incompatible element enrichment and the N-MORB are obviously depleted with some metasomatic effect, and E-MORB are geochemically intermediated. These rocks are distributed around the Majixueshan OIB and gabbros in a thickness greater than a thousand meters and transitionally change along the ophiolite extension in a west-east direction, showing a symmetric distribution pattern as centered by the Majixueshan OIB, that is, from N-MORB, OIB and E-MORB association in the Dur'ngoi area to OIB in the Majixueshan area and then to N-MORB, OIB and E-MORB assemblage again in the Buqingshan area. By consideration of the rock association, the rock spatial distribution and the thickness of the mafic rocks in the Majixueshan, coupled with the metasomatic relationship between the OIB and MORB sources, it can be argued that the Majixueshan probably corresponds to an ancient hotspot or an ocean island formed by mantle plume on the A'nyemaqeh ocean ridge, that is the ridge-centered hotspot, tectonically similar to the present-day Iceland hotspot. 相似文献
588.
Multi-scale heterogeneity of soil moisture following snow thawing in Haloxylon ammodendron shrubland
Spatial variation of soil moisture after snow thawing in South Gurbantunggut was quantitatively studied using ANOVA and geostatistics at various scales. The results show that the soil moisture heterogeneity varies along with spatial scales. At the shrub individual scale, there is a gradient in soil moisture from shrub-canopied area to canopy margin and to the interspaces between shrubs. At the community scale, soil moisture is highly autocorrelated and the semivariogram is fitted as spherical model, with an 89.6% structural variance and a range of 4.02 m. In addition, Kringing map indicates that the soil moisture distribution pattern after snow thawing is highly consistent with the shrub patch pattern. At the typical inter-dune transect scale, soil moisture presents a pattern of high value at inter-dune depression and low value at dune, and this variation is fitted as Gaussian model with a structural variance of 95.8% and a range of 66.16 m. The range is comparable with the scale of topography zoning, suggesting that the topography pattern controls the pattern of snowmelt at this scale. The evidence indicates that the heterogeneity of soil moisture at various scales is controlled by various land surface processes after snow thawing. For Gurbantunggut Desert, the spatial heterogeneity of snowmelt at various scales is ecologically valuable, because it promotes the utilization efficiency of the snowmelt for the desert vegetation. 相似文献
589.
The mean value concept in mono-linear regression of multi-variables and its application to trace studies in geosciences 总被引:1,自引:1,他引:1
A J T JULL 《中国科学D辑(英文版)》2007,50(12):1828-1834
The "mean value concept" in a mono-linear regression of multi-variables is clarified.Its applications to reconstruction of the past 90-year salinity of the sea surface water in Xisha Islands and to tracing the past 80 ka paleo-geomagnetic events from the Luochuan loess 10Be record are introduced in detail,which show the significance and the potential of the "mean value concept" in geoscience research. 相似文献
590.
Measurements of topsoil magnetic susceptibility are often used for quick assessment of soil contamination of anthropogenic
origin, with heavy metals or other pollutants. However, because of complicated correlations between low-field magnetic susceptibility
(shortened to magnetic susceptibility) of topsoil and soil pollution, the outcome of a field magnetometry survey can not be
related directly to soil pollution. For each case study, the results should be interpreted on their own taking into account
not only the type of pollution but also pedogenic, biogenic and environmental factors. In practice, it is very difficult to
measure and consider all these factors. Here we illustrate the merit of geostatistical methods, which are focused on the spatial
variability of a phenomenon, in the interpretation of soil magnetometry results.
This article presents the analysis of spatial variability of top soil layers magnetic susceptibility-within the Upper Silesia
Industrial Region (USIR)-using semivariance analysis. It also explains how to adjust the sampling density of field magnetometry
measurements to spatial variability of the soil pollution as well as to the spatial scale of the investigated area. For this
purpose, the values of magnetic susceptibility have been measured by using various sampling densities at areas of different
size located within USIR. This enabled to determine the main scales of magnetic susceptibility spatial variability of soils
within USIR using semivariance. A few distinct scales of variability were found from the site scale to a more regional scale.
Variability ranges of 30 km, 12 km, and 5 km refer to the large regional scale, whereas smaller ranges of few hundreds down
to a few tens of meters, can be attributed to the local (site) scale. In addition, the precision of the measuring campaigns,
performed within USIR with different sampling densities, was compared through the analysis of the spatial variability of the
soil magnetic susceptibility signal by using ordinary kriging.
jarek97@yahoo.com, piotr.fabijanczyk@is.pw.edu.pl 相似文献