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101.
BassamFAIBassam 《中国地质大学学报(英文版)》2003,14(1):52-58
Landsat TM digital spectral data of Lancang-Jinghong area (Yunnan Province) has been used for the purpose of geological interpretation. To meet this object, different image processing tech-niques including selected band color composites, principal component analysis and IHS decorrelation stretching are used to improve the discrimination of different lithologicai and structural features in the area. It was found that IHS decorrelation stretching images obtained from the transformation of false color composite 741 (in red, green and blue) provided the best results based on the original data. By combining the characteristics of images produced by different approaches and other canonically trans-formed images with available geological data and surface observations, the geological interpretation could be done with satisfactory degree of accuracy. 相似文献
102.
BassamFAIBassam 《中国地质大学学报(英文版)》2003,14(3):283-292
Gengma region, Sanjiang district is known to have some large-scale gold deposits. GIS predictive model for hydroghermal gold potential was carried out in this region using weights of evidence modeling technique. Datasets used include large-scale hydroghermal gold deposit records, geological, geophysical and remote sensing imagery. Based on the geological and mineral characteristics of areas with known gold occurrences in Sanjiang, several geological features were thought to be indicative of areas with potential for the occurrence of hydroghtermal gold deposits. Indicative features were extracted from geoexploration datasets for use as input in the predictive model. The features include host rock lithology, geologic structures, wallrock alteration and associated (volcanic-plutonic) igneous rocks. To determine which of the indicative geological features are important spatial predictors of area with potential for gold deposits, spatial analysis was done through the modeling method. The input maps were buffered and the optimum distance of spatial association for each geological feature was determined by calculating the contrast and studentized contrast. Five feature maps were converted to binary predictor patterns and used as evidential layers for predictive modeling. The binary patterns were integrated in two combinations, each of which consists of four patterns in order to avoid over prediction due to the effect of duplicate features in the two structural evidences. The two produced potential maps define almost similar favorable zones. Areas of intersections between these zones in the two potential maps placed the highest predictive favorable zones in the region. 相似文献
103.
Adsorption of dimethoate and 2,4-D on Jordan Valley soils and their environmental impacts 总被引:1,自引:0,他引:1
M. Al Kuisi 《Environmental Geology》2002,42(6):666-671
The adsorption process of dimethoate and 2,4-dichloro-phenoxy acetic acid (2,4-D) on Jordan Valley soils from aqueous solution at 25 °C has been studied. The adsorption isotherms may be classified as L-type of the Giles classification. The Kads values (Freundlich equation) vary between 1.01 (JV5) and 10.36 (JV7) for dimethoate insecticide and between 4.41 (JV5) and 14.87 (JV7) for 2,4-D herbicide, depending on the soil type. The adsorption of 2,4-D herbicide on soils in the study area is about threefold higher than that of dimethoate insecticide. The adsorption process of dimethoate and 2,4-D pesticides seem to be primarily controlled by the organic matter content of the soils and the clay content (most especially montmorillonite). 相似文献
104.
Sedimentologic study of carbonated sediments of the Rmah-I member (Coniacian–Santonian) of Jabal Abtar, central southern Palmyrides (Central Syria), uncovers phosphatic levels, associated with marine vertebrate remains, that give evidence of an early episode of the Senonian phosphatogenesis in the Palmyrides. Sedimentary sequence analysis reveals a gradual marine transgression during the Senonian. Phosphatic sedimentation occurred in a shallow neritic marine environment almost connected with the open sea. Condensed sedimentation could have contributed to the phosphatogenesis. To cite this article: A.K. Al Maleh, N. Bardet, C. R. Geoscience 335 (2003). 相似文献
105.
Schreider Al. A. Schreider A. A. Sazhneva A. E. Kluev M. S. Brehovskih A. L. 《Oceanology》2019,59(1):133-142
Oceanology - A new map of the axes of linear magnetic anomalies for eastern regions of the Eurasian Basin has been compiled. Based on the results of Russian geomagnetic surveys, paleoanomaly C25... 相似文献
106.
Guo Congcong Bai Xiaoyun Abdullah Al Mamun Sikder Mohammad Nurul Azim Xu Henglong 《Ocean Science Journal》2019,54(1):87-95
Ocean Science Journal - Biological trait analysis (BTA) of protozoan communities has been used a useful bioindicator of environmental quality status in marine ecosystems. To determine the optimal... 相似文献
107.
Soloviev An. A. Soloviev Al. A. Gvishiani A. D. Nikolov B. P. Nikolova Yu. I. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(9):1363-1373
Izvestiya, Atmospheric and Oceanic Physics - Zones of higher seismic hazard occupy about 20% of Russia’s territory, and 5% are characterized by extremely high hazard. These latter are, in... 相似文献
108.
Impacts of Anthropogenic Land Use Changes on Nutrient Concentrations in Surface Waterbodies: A Review 总被引:1,自引:0,他引:1 下载免费PDF全文
Increased population leads to land use (LU) changes from natural to urban and agricultural LU. These disturbances not only decrease the natural treatment potential but they also worsen surface water quality (SWQ). The aim of this review is to assess studies about impacts of anthropogenic LU changes on levels of nutrient concentrations in surface waterbodies, highlighting the important parameters needed for an integrated simulation. The results reported in the literature are not always fully consistent. These contradictory results can sometimes be explained by field measurements under different climatic conditions, different features of landscapes, air deposition rates on ground surfaces, and groundwater flow interactions with surface water. Integrated modelling has been suggested to overcome these inconsistencies. Physical‐based and empirical models are the most popular approaches for LU‐SWQ studies. Generally, anthropogenic LU such as agricultural and urban areas usually enhances nutrient concentrations much more than natural lands such as forest and barren. Developing sustainable metropolitan areas instead of rural areas, establishing high‐standard wastewater treatment plants, and practicing efficient fertiliser application would ameliorate the poor nutrient conditions in SWQ. Riparian vegetation, grassed swales, and construction of artificial wetlands as buffer zones are the most promising natural water quality control measures. 相似文献
109.
Abdullah H. A. Dehwah Samir Al‐Mashharawi Kim Choon Ng Thomas M. Missimer 《Ground water》2017,55(3):316-326
An investigation of a sea water reverse osmosis desalination facility located in western Saudi Arabia has shown that aquifer treatment of the raw sea water provides a high degree of removal of natural organic matter (NOM) that causes membrane biofouling. The aquifer is a carbonate system that has a good hydraulic connection to the sea and 14 wells are used to induce sea water movement 400 to 450 m from the sea to the wells. During aquifer transport virtually all of the algae, over 90% of the bacteria, over 90% of the biopolymer fraction of NOM, and high percentages of the humic substance, building blocks, and some of the low molecular weight fractions of NOM are removed. Between 44 and over 90% of the transparent exopolymer particles (TEP) are removed with a corresponding significant reduction in concentration of the colloidal fraction of TEP. The removal rate for TEP appears to be greater in carbonate aquifers compared to siliciclastic systems. Although the production wells range in age from 4 months to 14 years, no significant difference in the degree of water treatment provided by the aquifer was found. 相似文献
110.
The seismicity of the northeastern part of the Indian Ocean in connection with the general structural peculiarities of the
main tectonic structures of the bottom is presented. The three main ranges of higher seismic activity at the depths of 0–17,
20–27, and 32–35 km divided by aseismic layers are revealed. The seismic activity at depths of more than 35 km is almost not
detected both for the ocean and for the Indian peninsula. The nature of the distribution of the seismicity as such in the
lithosphere is discussed. Using the results of anomalous au]gravitational field transformations, the prolongation of the East
Indian Ridge structure is revealed to 19 degrees north, while the relationship of the Afanasy Nikitin Rise and the 85th Degree
Ridge is not reflected at the tranforms. In the Cocos Basin, the mutually perpendicular disturbance zones of northeastern
and northwestern strike, as well as the point of their crossing, where the maximal number of earthquake foci are concentrated,
are distinguished. A conclusion concerning the substantial disturbance of the strength properties of the lithosphere in this
zone as a consequence of the geodynamical processes, which are accompanied by fracture tectonics, is reached. 相似文献