全文获取类型
收费全文 | 589篇 |
免费 | 4篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 10篇 |
环保管理 | 32篇 |
综合类 | 317篇 |
基础理论 | 98篇 |
污染及防治 | 100篇 |
评价与监测 | 22篇 |
社会与环境 | 14篇 |
灾害及防治 | 2篇 |
出版年
2018年 | 5篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2013年 | 20篇 |
2012年 | 10篇 |
2011年 | 22篇 |
2010年 | 16篇 |
2009年 | 15篇 |
2008年 | 22篇 |
2007年 | 19篇 |
2006年 | 7篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 16篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 12篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1975年 | 5篇 |
1973年 | 6篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1970年 | 8篇 |
1967年 | 9篇 |
1966年 | 8篇 |
1965年 | 11篇 |
1963年 | 14篇 |
1962年 | 11篇 |
1961年 | 12篇 |
1960年 | 10篇 |
1959年 | 13篇 |
1958年 | 9篇 |
1957年 | 7篇 |
1956年 | 9篇 |
1955年 | 7篇 |
1954年 | 5篇 |
1953年 | 6篇 |
1952年 | 6篇 |
1930年 | 4篇 |
1928年 | 4篇 |
1926年 | 6篇 |
1914年 | 6篇 |
1913年 | 10篇 |
排序方式: 共有598条查询结果,搜索用时 491 毫秒
191.
192.
Werner Kuhn 《Die Naturwissenschaften》1963,50(6):171-177
193.
The Science of Nature - 相似文献
194.
195.
196.
197.
198.
199.
Bernd Hanisch Bettina Abbas Werner Kratz Gerrit Schüürmann 《Environmental Sciences Europe》2004,16(4):223-238
Goal
In the Brandenburg State Office for the Environment an approach to assess the potential risk of drug residues in aquatic ecosystems has been developed based on an investigation of the consumption amounts in 1999 to identify or to exclude a potential environmental risk of important human drugs and further to define priority substances for monitoring programs in Brandenburg in the future.Method
This assessment approach tested with 60 drug agents is based on an exposure estimation considering the main path for the entry human—waste water—sewage plant—surface water, on a substance specific analysis of effects and on an analysis of the environmental fate as compartment distribution, bioaccumulation and persistence.Results
In Brandenburg surface waters the drug agent concentration for eight of the considered substances is supposed to be greater than 1 μg/l and for at least 13 of the considered substanoes the PNEC in aquatic ecosystems is assumed to be lower than 1 μg/l. A potential risk for the environment can be seen for the antibiotics Ciprofloxacin-HCl and Clarithromycin, the disinfectants Benzalkonium Chloride, Cocospropylendiaminguaniacetat, Glucoprotamine, Laurylpropylenediamine and Polyvidone-iodine, the sexual hormon Ethinylestradiol, the antidiabetic Metformin-HCl, the antiepileptic Carbamazepine and the lipid regulator Clofibrinic acid on the basis of effects because their PEC:PNEC-relation is about 1 or higher. For further 19 drug agents an environmental risk is to be assumed because of their environmental behaviour without support by ecotoxicological data at present.Conclusion
Although there is only a small base of valid ecotoxicological data, this risk assessment shows that adverse effects in the aquatic environment by some drug agents cannot be excluded. However, it should be noted that this first assessment gives only a crude orientation. Appropriate test data are necessary to refine the assessment in future. 相似文献200.
Werner von Bloh Christine Bounama Klaus EisenackBrigitte Knopf Oliver Walkenhorst 《Ecological modelling》2008
To determine the influence of the biosphere on weathering we use a dynamic model of the global carbon cycle. It takes into account the most important processes for the long-term evolution of the Earth. The model is solved under a slowly changing environment of increasing solar luminosity and volcanic activity and continental area. By comparing the model results for the global average temperature with data derived from δ18O values from cherts it is possible to quantify the biogenic enhancement factor of weathering. For this purpose a newly developed inverse viability method is applied, which allows for calculating the range of possible biogenic enhancement factors consistent with the data. We find that in the Precambrian the weathering was 5.4 times lower than in the Phanerozoic era. This supports the hypothesis that the Cambrian explosion was caused by a positive feedback between the spread of biosphere, increased silicate weathering, and a consequent cooling of the climate. 相似文献