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201.
在1996年8月5日——1997年5月15日对Hale-Bopp彗星进行了照相观测,多次观测到Hale-Bopp彗星彗核的小规模分裂,喷流,壳层结构及彗发的膨胀现象。 相似文献
202.
203.
Modern hot spring geochemistry at the Tanlu fault and Jiaoliao block in eastern China 总被引:1,自引:0,他引:1
Zhiguan Shangguan Jikui Du Wei Zang Jihua Wang Lingchang Kong Songsheng Gao 《中国科学D辑(英文版)》1998,41(1):87-94
The δD, δ18O values of the hot springs are always more negative than those of the local cold springs. The main cause for the ocrurrence
is physically isotope fractionation during the deep circulating process of the groundwater. The relational expression between
the δD, δ18O values and the maximum circulating depths of the groundwaters is given. The gases escaped from the geothermal fluid are
mostly crust-derived gases in the studied area. The compressive structure of the Tanlu fault could extend to the deep crust,
and basically stop the ascent of deep-seated gases towards the surface.
Project supported by the National Natural Science Foundation of China (Grant No. 49373165) 相似文献
204.
华北板块东缘晚古生代火山活动及其大地构造含义 总被引:4,自引:0,他引:4
在华北板块东缘,从皖北,鲁西到冀中,辽东,分布着一条长达千余km的晚古生代北北东向火山活动带,已发现的火山岩主要为正常火山碎屑岩和沉积火山碎屑岩,岩石化学分析表明为钙碱系列中(酸)性火山岩,在华北晚古生代煤系中记录了这种强烈的火山活动,包含有丰富的火山碎屑以及由火山灰堆积蚀变而成的煤矸层(tonstein)。作者认为,在晚古生代,华北板块东缘可能存在一火山弧链,即华北板块东缘为一主支大陆边缘。 相似文献
205.
The studies on the structure and physical properties of the Earth‘s interior done by Chinese geophysicists from 1999 to 2002 were reviewed in this paper. It includes several research areas: the structure of the Earth‘s interiors using seismic tomography, anisotropy of the upper mantle in China and its adjacent areas, quality factor Qβ for S waves, subduction zone, mantle discontinuities, physical properties of Earth‘s materials and others. The review concerns mainly the contents, the methods and the results of the studies. It can be seen that new progress in the study on the structure and physical properties of the Earth‘s interior has been made in the last 4 years in China. It is shown on three aspects: advancement made on some preexistent areas; pioneering on some new fields and new methods adopted. 相似文献
206.
Based on a layered Theological model of the lithosphere, the velocity and stress distributions in the lithosphere under horizontal drag underneath were calculated using viscoelastic finite element method of plain strain with finite deformation. In the simulation, different conditions of drag and blocking were assumed to study their influences on the stress distribution and the coupling between different layers. Blocking depth has little influence on the stress level in the whole area and the coupling between different layers, but influences the stress state in the area around the blocking. The area covered by the high stress anomaly becomes larger when the blocking depth becomes deeper, but the magnitude of the value of the maximum shear stress decreases. The greater the viscosity differences between different layers of the lithosphere, the greater the possibility of decoupling between them. Under the drag of normal mantle convection (the convection velocity is about 20 cm · a?1), a lithosphere with a Theological structure similar to that of North China could not have decoupling between different layers, while could have stress distribution with magnitude of several MPa to tens of MPa and could have anomalous areas with stress accumulation if the geological structure is complicated. 相似文献
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208.
本文基于日本东京湾、伊势湾和浜名湖的调查资料,详细地比较了这3个海湾海水中的溶存甲烷浓度、饱和度。表层海水中,溶存甲烷浓度以供名湖最高,达95nmol/dm3,伊势湾和东京湾相近,分别为41nmol/dm3和37nmol/dm3;其表层测定浓度是其平衡浓度的13~78倍,并分别计算了这3个海湾中甲烷的海气交换通量;用平均值外推法得出全球海洋环境中总的甲烷海气交换通量为6.3Tg/a。 相似文献
209.
210.
Zang Jiaye 《海洋学报(英文版)》1995,(4)
The distribution of methane in the Tokyo-wanZangJiaye(ReceivedAugust8,1995;acceptedSeptember2,1995)Abstract:Elevenstationswer... 相似文献