全文获取类型
收费全文 | 654篇 |
免费 | 3篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 4篇 |
环保管理 | 21篇 |
综合类 | 372篇 |
基础理论 | 121篇 |
污染及防治 | 99篇 |
评价与监测 | 20篇 |
社会与环境 | 17篇 |
灾害及防治 | 5篇 |
出版年
2019年 | 6篇 |
2018年 | 11篇 |
2017年 | 9篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 27篇 |
2012年 | 12篇 |
2011年 | 13篇 |
2010年 | 18篇 |
2009年 | 17篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 8篇 |
1999年 | 23篇 |
1998年 | 11篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1992年 | 6篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1967年 | 6篇 |
1966年 | 8篇 |
1965年 | 7篇 |
1964年 | 9篇 |
1961年 | 10篇 |
1960年 | 6篇 |
1955年 | 7篇 |
1952年 | 6篇 |
1942年 | 6篇 |
1941年 | 8篇 |
1940年 | 9篇 |
1938年 | 6篇 |
1937年 | 12篇 |
1936年 | 10篇 |
1935年 | 9篇 |
1934年 | 11篇 |
1933年 | 7篇 |
1931年 | 7篇 |
1929年 | 8篇 |
1922年 | 6篇 |
1921年 | 7篇 |
1920年 | 5篇 |
排序方式: 共有665条查询结果,搜索用时 109 毫秒
61.
The problems of reproduction of Octopus vulgaris and the seasonal distribution in the sea of planktonic larvae, benthonic juveniles and adults are discussed. The influence of environmental factors on growth is shown by experimental studies in the laboratory, and the difficulties of interpreting field data are emphazised.Dedicated to Professor Dr. Adolf Portmann on his 75th birthday, 27 May, 1972Laboratoire associé au C.N.R.S. 相似文献
62.
63.
64.
The mining industry has been one of the backbones of the socialist countries of Eastern Europe, not only in economic, but also in political, terms. Three years after the beginning of economic reforms, the mining industry in all the Eastern European countries is facing dramatic changes. Most mines are mining ores below acceptable cut-off grades, and there is no hope of finding new, richer deposits. Downstream metallurgical industries will need to replace their former suppliers. In addition, the social contract that had been maintained under the socialist governments is about to be undone and a new form of internal organization must be found. The success of the economic reforms in Eastern Europe depends upon the capacity to develop new industrial relations: the large mining combinates will have to be transformed into competitive capitalist enterprises and the role of the state must be redefined. Prospects for this transformation vary greatly, from metal to metal and from country to country. Finally, restructuring in Eastern Europe will also affect European and world markets, both on the supply and demand sides. The integration of the Eastern European mining industries into the international mining community should be the medium-term goal of all the participants . 相似文献
65.
66.
67.
68.
69.
Goal and Scope
Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis.Methods
At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda.Results and Conclusion
The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor internationally. Time trend studies have been available for lead and cadmium since 1985/86, and for zinc since 1987. The studies show a steady decrease of the heavy metals on a state-wide average and especially in the ‘Odenwald’ and ‘Black Forest’ hills with their formerly highly polluted earthworm habitats. Today, the level of these metals in the earthworms is low with few exceptions. This holds true for other heavy metals as well.Recommendations and Perspectives
The state-wide decreasing very low heavy metal burden of forest observation plots far from known emission sources can be considered a success of air pollution abatement measures. Because of the ongoing atmospheric deposition of heavy metals, regular observation should continue in order to estimate time trends and to recommend the reduction of emissions when precautionary values (part 2) are exceeded. 相似文献70.
Biodegradation studies of selected priority acidic pesticides and diclofenac in different bioreactors 总被引:1,自引:0,他引:1
González S Müller J Petrovic M Barceló D Knepper TP 《Environmental pollution (Barking, Essex : 1987)》2006,144(3):926-932
The biodegradation of selected priority acidic pesticides MCPP, MCPA, 2,4-D, 2,4-DP and bentazone and the acidic pharmaceutical diclofenac was investigated using a membrane bioreactor (MBR) and a fixed-bed bioreactor (FBBR). A pilot plant MBR was fed with raw water spiked with the selected compounds. The experiment was repeated every week during four weeks to enhance the adaptation of microorganisms. In order to further study the biodegradability of these compounds, degradation studies in a FBBR were carried out. All the samples were analysed by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS). The results indicate that in the MBR compounds except for bentazone were eliminated within the first day of the experiment at rates ranging from 44% to 85%. Comparing these results with the degradation rates in the FBBR showed that in the latter only MCPP, MCPA 2,4-D and 2,4-DP were degraded after a much longer adaptation phase of microorganisms. 相似文献