全文获取类型
收费全文 | 2931篇 |
免费 | 187篇 |
国内免费 | 11篇 |
专业分类
测绘学 | 220篇 |
大气科学 | 210篇 |
地球物理 | 847篇 |
地质学 | 1053篇 |
海洋学 | 139篇 |
天文学 | 480篇 |
综合类 | 34篇 |
自然地理 | 146篇 |
出版年
2024年 | 5篇 |
2023年 | 14篇 |
2022年 | 25篇 |
2021年 | 51篇 |
2020年 | 64篇 |
2019年 | 55篇 |
2018年 | 180篇 |
2017年 | 145篇 |
2016年 | 230篇 |
2015年 | 198篇 |
2014年 | 212篇 |
2013年 | 239篇 |
2012年 | 191篇 |
2011年 | 181篇 |
2010年 | 156篇 |
2009年 | 152篇 |
2008年 | 119篇 |
2007年 | 98篇 |
2006年 | 96篇 |
2005年 | 57篇 |
2004年 | 69篇 |
2003年 | 51篇 |
2002年 | 49篇 |
2001年 | 48篇 |
2000年 | 37篇 |
1999年 | 23篇 |
1998年 | 54篇 |
1997年 | 30篇 |
1996年 | 24篇 |
1995年 | 26篇 |
1994年 | 24篇 |
1993年 | 14篇 |
1992年 | 19篇 |
1991年 | 16篇 |
1990年 | 22篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 14篇 |
1984年 | 5篇 |
1983年 | 11篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1973年 | 6篇 |
1972年 | 9篇 |
1971年 | 5篇 |
排序方式: 共有3129条查询结果,搜索用时 656 毫秒
91.
A. Nadgórska-Socha M. Kandziora-Ciupa R. Ciepał G. Barczyk 《International Journal of Environmental Science and Technology》2016,13(7):1741-1752
The accumulation efficiency of selected trace elements in the leaves of Melandrium album and Robinia pseudoacacia grown on heavy metal contaminated sites in comparison with a non-contaminated one was evaluated. The study was undertaken to calculate air pollution tolerance index and to determine the contents of selected metabolites: glutathione, non-protein thiols, ascorbic acid, chlorophyll and the activity of antioxidant enzymes: guaiacol peroxidase and superoxide dismutase. Such estimations can be useful in better understanding of plants defense strategies and potential to grow in contaminated environments. The results in the most contaminated site revealed higher contents of metals in M. album leaves, especially Zn, Cd and Pb (3.4, 6 and 2.3 times higher, respectively) in comparison with the R. pseudoacacia. Better accumulation capacity found in M. album was shown by metal accumulation index values. The plants could be used as indicators of Zn, Cd (both species) and Pb (M. album) in the soil. Glutathione content (in both species) and peroxidase activity (in M. album), general markers of heavy metals contamination, were increased in contaminated sites. In most cases in contaminated areas R. pseudoacacia had decreased ascorbic acid and chlorophyll levels. Opposite tendency was recorded in M. album leaves, where similar or higher contents of the above-mentioned metabolites were found. In our study, M. album and R. pseudoacacia proved to be sensitive species with the air pollution tolerance index lower than 11 and can be recommended as bioindicators. 相似文献
92.
93.
94.
95.
96.
97.
98.
Grajales-Nishimura José Manuel Ramos-Arias Mario Alfredo Solari Luigi Murillo-Muñetón Gustavo Centeno-García Elena Schaaf Peter Torres-Vargas Ricardo 《International Journal of Earth Sciences》2018,107(3):1005-1031
International Journal of Earth Sciences - The Juchatengo complex (JC) suite is located between the Proterozoic Oaxacan complex to the north and the Xolapa complex to the south, and was amalgamated... 相似文献
99.
Ćwiek Mateusz Matusiak-Małek Magdalena Puziewicz Jacek Ntaflos Theodoros 《International Journal of Earth Sciences》2018,107(5):1731-1753
International Journal of Earth Sciences - The Oligocene/Miocene basanite from Pilchowice (Sudetes Mts., SW Poland) carries numerous small xenoliths of mantle peridotite, mostly harzburgite. The... 相似文献
100.
Słodczyk Elżbieta Pietranik Anna Glynn Sarah Wiedenbeck Michael Breitkreuz Christoph Dhuime Bruno 《International Journal of Earth Sciences》2018,107(6):2065-2081
International Journal of Earth Sciences - The Polish Lowlands, located southwest of the Teisseyre–Tornquist Zone, within Trans-European Suture Zone, were affected by bimodal, but dominantly... 相似文献