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991.
Simulated multi-scale watershed runoff and sediment production based on GeoWEPP model 总被引:5,自引:2,他引:3
YU Xinxiao ZHANG Xiaoming NIU Lili Prof. Dr. Key Laboratory of Soil Water Conservation Desertification Combating Ministry of Education School of Soil Water Conservation Beijing Forestry University Beijing China Dr. China Institute of Water Resource Hydropower Research Beijing China Dr. ... 《国际泥沙研究》2009,24(4):465-478
The runoff and sediment yield data from the Qiaozidonggou, Qiaozixigou, and Lu'ergou watersheds, in the Loess Plateau of China are used to calibrate and validate the runoff and sediment yield simulated by GeoWEPP model of the WEPP Model at watershed scale. The indices of relative error, R, correlation coefficient, Re, and Nash-Suttcliffe efficiency coefficient Ens are used to evaluate the model fit. The eco-hydrological responses in the Luoyugou and Lu'ergou watersheds are also forecast based on the WEPP Model. Meanwhile, the relation between vegetation pattern changes and sediment yield in the watershed is discussed, and the responses of runoff and sediment yield in the watersheds concerning forest growth stages are studied. The results show that the relative errors of simulated values of runoff and sediment yield are below 30%, the correlation coefficients axe above 0.90, and the Nash-Suttcliffe efficiency coefficients axe above 0.80. The simulation results present satisfactory performance, thus, the model could be used to simulate the runoff and sediment yield in these small watersheds. It is also observed that soil erosion tended to become severe as precipitation increased in the watershed, while soil erosion has a decreasing trend as forest cover increases and vegetation pattern is optimized. When the watershed is fully covered by forest, erosion and sediment yield are minimized. When the forest cover is about 30% and evenly distributed in the watershed, the erosion intensity is lower than if the forest cover is collectively distributed in the watershed. Erosion varies with different forest growth stages in the watershed; it is more serious at the young and near planting stage and is the smallest at the mature forest stage. 相似文献
992.
Yaqiong Dai Jinwei Ren Xuhui Shen Jingfa Zhang Shunying Hong Institute of Earthquake Science China Earthquake Administration Beijing China Institute of Crustal Dynamics Beijing China 《地震学报(英文版)》2009,(3):263-269
Digital elevation model (DEM) can be generated by interferometric synthetic aperture radar (InSAR). In this paper, the interferometric processing and analyses are carried out for Damxung-Yangbajain area in Tibet, using a pair of Europe remote-sensing satellite (ERS)-1/2 tandem SAR images acquired on 6 and 7 April 1996. A portion of the In- SAR-derived DEM is selected and compared with the 1:50 000 DEM to determine the precision of the InSAR-derived DEM. The comparison indicates that the root mean squared er... 相似文献
993.
Jiren Xu Zhixin Zhao Institute of Geology Chinese Academy of Geological Sciences Beijing China 《地震学报(英文版)》2009,(6):651-658
In the present analysis on the relationships among the depth of lithosphere brittle fracture,seismotectonics and geothermal anomalous active in Tibetan plateau were investigated using the seismic dada from ISC and Chinese seismic net and geothermal data.The results suggest that the region of anomalously geothermal activity almost coincides with that of the normal faulting type earthquake.The geothermal anomaly activity region coincides spatially with that of the events deeper than 60 km as well as.The norma... 相似文献
994.
A case study of spatial heterogeneity of soil moisture in the Loess Plateau, western China: A geostatistical approach 总被引:9,自引:2,他引:7
BI Huaxing LI Xiaoyin LIU Xin GUO Mengxia LI Jun Prof. College of Soil Water Conservation Beijing Forestry University Beijing China Key Laboratory of Soil Water Conservation Desertification Combating Ministry of Education China Researcher Ji-xian National Ecological Station of China China Graduate student 《国际泥沙研究》2009,24(1):63-73
Soil moisture distribution shows highly variation both spatially and temporally. This study assesses the spatial heterogeneity of soil moisture on a hill-slope scale in the Loess Plateau in West China by using a geostatistical approach. Soil moisture was measured by time-domain reflectometry (TDR) in 313 samples. Two kinds of sampling scales were used (2 × 2 m and 20 ×20 m) at two soil layers (0-30 cm and 30-60 cm). The general characteristics of soil moisture were analyzed by a classical statistics method, and the spatial heterogeneity of soil moisture was analyzed using a geostatistical approach. The results showed that the spherical model is the best-fit model to simulate soil moisture on the experimental hill-slope. The parameters of this model indicated that the spatial dependence of soil moisture in the selected hill-slope was moderate. Even the 2 × 2 m sampling scale was too coarse to show the detailed spatial variances of soil moisture in this area. The dependent distance increased from 27.4 m to 494.16 m as the sampling scale became coarse (from 2× 2 m to 20 ×20 m). A map of soil moisture was generated by using original soil moisture data and interpolated values determined by the Kriging method. The average soil moisture (area weighted) in the different layers of soil was calculated on the basis of this map (10.94% for the 0-30 cm soil layer, 11.88% for the 30-60 cm soil layer). This average soil moisture is lower than the corresponding average effective soil moisture, which suggests that the soil moisture is not sufficient to support vegetation in this area. 相似文献
995.
QIAN FuYe ZHAO BiRu QIAN Wei ZHAO Jian HE ShiGen ZHANG HongKui LI ShiYu LI ShaoKun YAN GuLiang WANG ChengMin SUN ZhenKai ZHANG DongNing LU Jun ZHANG Ping YANG GuoJun SUN JiaLin GUO ChunSheng TANG YuXiong XU JianMing XIA KunTao JU Hang YIN BangHong LI Ming YANG DongSheng QI WeiLuo HE TaiMing GUAN HuaPing & ZHAO YuLin Institute of Geophysics China Earthquake Administration Beijing China Tianjin Hi-tech Development Co. Ltd Tianjin ... 《中国科学D辑(英文版)》2009,(10)
We deployed four geo-electric monitoring stations in Sichuan and Yunnan provinces from 2004, using the new generation of equipment (PS-100) and technologies to capture the HRT wave earthquake precursor. Before the Wenchuan Ms8.0 earthquake, we recorded the HRT wave precursor at the only operating station in Hongge (HG, Δ=465 km) and found that significant impending signal had been recorded at the station in the early morning ( 0―5 am) of 12th of May, 2008. The precursor for this earthquake is consistent wit... 相似文献
996.
997.
Effect of Phosphatization on Element Concentration of Cobalt-Rich Ferromanganese Crusts 总被引:4,自引:1,他引:3
E. H. De CARLO 《《地质学报》英文版》2005,79(3):349-355
1 Introduction Co-rich ferromanganese crusts occurring on submarine guyots have received much attention from scientists since the beginning of the 1980’s because they are enriched in Co, Mn, Pt, and rare earth elements (REEs), and have large potential mineral resources, occurring as they do on topographic highs relative to polymetallic nodules in the C-C (Clarion-Clipperton) zone (Halbach et al., 1982, 1989; Hein et al., 1992, 1999; Usui and Someya, 1997; Yamazaki and Sharma, 1998, 2000… 相似文献
998.
Origins of High H_2S-bearing Natural Gas in China 总被引:2,自引:0,他引:2
ZHU Guangyou ZHANG Shuichang LIANG Yingbo DAI Jinxing LI Jian Research Institute of Petroleum Exploration Development China National Petroleum Corporation Beijing 《《地质学报》英文版》2005,79(5):697-708
Natural gas containing hydrogen sulphide (H2S) has been found in several petroliferous basins in China, such as the Sichuan Basin, Bohai Bay Basin, Ordos Basin, Tarim Basin, etc. Natural gas with higher HES contents (HES 〉5 % mol.) is mostly distributed in both the gas reservoirs of Dukouhe, Luojiazhai, Puguang and Tieshanpo, which belong to the Triassic Feixianguan Formation in the northeastern Sichuan Basin and those of the Kongdian-Shahejie formations in the northeastern Jinxian Sag of the Jizhong Depression, Bohai Bay Basin. In the Sichuan Basin, the HES contents of natural gas average over 9% and some can be 17 %, while those of the Bohai Bay Basin range from 40 % to 92 %, being then one of the gas reservoirs with the highest H2S contents in the world. Based on detailed observation and sample analysis results of a total 5000 m of core from over 70 wells in the above-mentioned two basins, especially sulfur isotopic analysis of gypsum, brimstone, pyrite and natural gas, also with integrated study of the geochemical characteristics of hydrocarbons, it is thought that the natural gas with high HES contents resulted from thermochemical sulfate reduction (TSR) reactions. Among them, the natural gas in the Feixianguan Formation resulted from TSR reactions participated by hydrocarbon gas, while that in the Zhaolanzhuang of the Jinxian Sag being the product of TSR participated by crude oil. During the consumption process of hydrocarbons due to TSR, the heavy hydrocarbons were apt to react with sulfate, which accordingly resulted in the dry coefficient of natural gas increasing and the carbon isotopes becoming heavier. 相似文献
999.
贵州独山下泥盆统丹林组陆相地层中的U形潜穴 总被引:2,自引:0,他引:2
具蹼状构造的垂直 U形潜穴 Diplocraterion广泛产出于全球寒武纪—古近纪的滨浅海相中 ,被认为是 Seilacher(196 4 ,196 7)的 Skolithos遗迹相的主要分子 ,也见于中—新生代的河湖相中 ,被视为高能环境的重要分子。Diplocraterion在古生代陆相地层中的发现仍是首次。产于贵州独山丹林组陆相地层具有水平层理的黑色泥岩中的 Diplocraterion dushanensis ichnosp.nov.其近于平行的 U形栖管由许多的节管组成 ,节管和蹼状构造可能系造迹生物的居住潜穴阶段性地随沉积物的增厚而向上移动的过程中所形成 ,其造迹生物主要生活于泛滥平原相对平静贫氧的水体环境中。 相似文献
1000.
Uranium Series Chronology of the Late Pleistocene Basalt from the Longgang Volcanoes, Jilin Province
YU Fusheng HAN Song MA Zhibang XIE Ruijie Institute of High Energy Physics Chinese Academy of Sciences Beijing Key Laboratory for Hydrocarbon Accumulation Mechanism Ministry of Education University of Petroleum Beijing Institute of Geology Geophysics Chinese Academy of Sciences Beijing 《《地质学报》英文版》2005,79(2):211-214
1 IntroductionThe Longgang volcanic cluster located in the middle partof Longgang Mountain is one of the active volcanoes innortheast China, potentially hazardous of explosion in thefuture (Fan et al., 2002). Within an area of 1700 km2, thereare about 160 volcanic cones, craters and maars (Ou, 1984).Among these volcanoes, the Jinlongdingzi and Dayizishanvolcanoes which are well studied have experiencedrepetitious eruptions (Wang and Jin, 1999). Detailedresearch on their eruption cycles is … 相似文献