全文获取类型
| 收费全文 | 433篇 |
| 免费 | 70篇 |
| 国内免费 | 98篇 |
专业分类
| 测绘学 | 15篇 |
| 大气科学 | 105篇 |
| 地球物理 | 95篇 |
| 地质学 | 231篇 |
| 海洋学 | 33篇 |
| 天文学 | 44篇 |
| 综合类 | 34篇 |
| 自然地理 | 44篇 |
出版年
| 2023年 | 8篇 |
| 2022年 | 18篇 |
| 2021年 | 16篇 |
| 2020年 | 17篇 |
| 2019年 | 13篇 |
| 2018年 | 19篇 |
| 2017年 | 21篇 |
| 2016年 | 16篇 |
| 2015年 | 12篇 |
| 2014年 | 15篇 |
| 2013年 | 20篇 |
| 2012年 | 20篇 |
| 2011年 | 21篇 |
| 2010年 | 16篇 |
| 2009年 | 20篇 |
| 2008年 | 23篇 |
| 2007年 | 15篇 |
| 2006年 | 13篇 |
| 2005年 | 20篇 |
| 2004年 | 15篇 |
| 2003年 | 10篇 |
| 2002年 | 18篇 |
| 2001年 | 14篇 |
| 2000年 | 23篇 |
| 1999年 | 24篇 |
| 1998年 | 27篇 |
| 1997年 | 24篇 |
| 1996年 | 19篇 |
| 1995年 | 16篇 |
| 1994年 | 20篇 |
| 1993年 | 8篇 |
| 1992年 | 9篇 |
| 1991年 | 9篇 |
| 1990年 | 6篇 |
| 1989年 | 6篇 |
| 1988年 | 5篇 |
| 1987年 | 3篇 |
| 1986年 | 2篇 |
| 1985年 | 6篇 |
| 1984年 | 3篇 |
| 1983年 | 1篇 |
| 1982年 | 3篇 |
| 1978年 | 1篇 |
| 1971年 | 1篇 |
| 1938年 | 1篇 |
| 1936年 | 4篇 |
排序方式： 共有601条查询结果，搜索用时 15 毫秒
61.
62.
63.
65.
Natural Hazards - Tsunamis occur not only in marine settings but also in lacustrine environments. Most of the lacustrine tsunamis are caused by seismically- or aseismically-triggered mass... 相似文献
66.
67.
68.
A comparison has been made between the predictions of the theory for radial variations of both Alfvénic fluctuations and solar wind proton temperatures proposed by Tu (1987, 1988) and the statistical results of hourly averaged plasma and magnetic field data observed by Helios 1 and 2 from launch through 1980 for different solar wind speed regimes. The comparison shows that for speed ranges between 500–800 km s-1, the radial variation of the proton temperature between 0.3 and 1 AU can be explained by heating from the cascade energy determined by the radial variation of the total variance of magnetic field vector. The explanation of the radial variations of both temperature and the total variance of magnetic fields for speed ranges less than 400 km s -1 is less clear.This project was supported by National Natural Science Foundation of China for Tu's part of the work. 相似文献
69.
通过对龙永煤田童子岩组煤系顶部鲕状带"鲕粒"赋存规律及其矿物学特征、宏观特征、围岩特征的野外研究及镜下观察,分析了"鲕粒"的成因及其岩相意义,为龙永煤田童子岩组顶部地层提供了对比依据. 相似文献
70.
Release of heavy metals during weathering of the Lower Cambrian Black Shales in western Hunan,China 总被引：8，自引：0，他引：8
Bo?PengEmail author Zhaoliang?Song Xiangling?Tu Meilian?Xiao Fucheng?Wu Huanzhe?Lv 《Environmental Geology》2004,45(8):1137-1147
Weathering of heavy metal enriched black shales may be one of the most important sources of environmental contamination in areas where black shales are distributed. Heavy metal release during weathering of the Lower Cambrian Black Shales (LCBS) in western Hunan, China, was investigated using traditional geochemical methods and the ICP-MS analytical technique. Concentrations of 16 heavy metals, 8 trace elements and P were measured for samples from selected weathering profiles at the Taiping vanadium ore mine (TP), the Matian phosphorous ore mine (MT), and Taojiang stone-coal mine (TJ). The results show that the bedrock at these three profiles is enriched with Sc, V, Cr, Co, Ni, Cu, Zn, Pb, Th, U, Mo, Cd, Sb, Tl, and P. Based on mass-balance calculation, the percentages of heavy metals released (in % loss) relative to immobile element Nb were estimated. The results show significant rates of release during weathering of: V, Cr, Co, Ni, Cu, Zn, U, Mo, Cd, Sn, Sb, and Tl for the TP profile; Sc, Cr, Mn, Co, Ni, Cu, Zn, Pb, Th, Cd, and Sn for the MT profile; and Sc, Mn, Co, Ni, Zn, Th, Cd, Sn, and Tl for the TJ profile. Among these heavy metals, Co, Ni, Zn, Cd, and Sn show very similar features of release from each of the three weathering profiles. The heavy metals released during weathering may affect the environment (especially topsoil and surface waters) and are possibly related to an observed high incidence of endemic diseases in the area. 相似文献