全文获取类型
收费全文 | 519篇 |
免费 | 5篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 10篇 |
废物处理 | 14篇 |
环保管理 | 42篇 |
综合类 | 167篇 |
基础理论 | 102篇 |
环境理论 | 1篇 |
污染及防治 | 161篇 |
评价与监测 | 12篇 |
社会与环境 | 20篇 |
灾害及防治 | 1篇 |
出版年
2022年 | 5篇 |
2021年 | 9篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 20篇 |
2012年 | 25篇 |
2011年 | 27篇 |
2010年 | 17篇 |
2009年 | 22篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 5篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1986年 | 6篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1974年 | 12篇 |
1973年 | 11篇 |
1963年 | 5篇 |
1962年 | 3篇 |
1961年 | 3篇 |
1959年 | 3篇 |
1958年 | 5篇 |
1957年 | 6篇 |
1955年 | 3篇 |
1915年 | 3篇 |
排序方式: 共有530条查询结果,搜索用时 15 毫秒
71.
Petroleum products are complex mixtures of hydrocarbons. They are important as constituents of fuels and lubricants, and as key raw materials for the chemicals industry. Since there is a potential for accidental releases to the aquatic environment, bioaccumulation of higher hydrocarbons is of concern. Here, the bioconcentration behaviour of two representative hydrocarbons, the dodecane isomers n-dodecane and 2,2,4,6,6-pentamethylheptane (PMH), was investigated in fathead minnows at concentrations in water below their maximum aqueous solubility. The concentration of n-dodecane in fish did not exceed our method limit of detection of 60 μg/kg. In contrast, PMH could be quantified in fish. No significant increase in the ratio of PMH concentrations in fish to water could be detected indicating that an exposure time of 4–10 days is sufficient to approach steady-state. For n-dodecane the upper limit of the bioconcentration factor (BCF) is estimated by dividing the method limit of detection by the exposure concentration and a value of 240 l/kg is derived. For PMH the bioconcentration factor, estimated as the average fish/water concentration ratio during the steady-state part of the experiment, ranges between 880 and 3500 l/kg. The BCFs of both compounds are small compared to their hydrophobicity. Given that both linear and branched hydrocarbons are known to be biotransformed by fish, it appears that efficient metabolism of the test compounds in fathead minnows prevents bioaccumulation. 相似文献
72.
Adenosine triphosphate (ATP) content and carbon dioxide (CO2) production in soil vary considerably, depending on soil type, water content, light, stirring of soil, storage conditions, date of sampling, and chemicals added. In most soils, the biomass calculated on the basis of ATP-content was in line with that calculated on the basis of CO2-production. 相似文献
73.
74.
75.
76.
77.
Sources of metals in New York City wastewater 总被引:1,自引:0,他引:1
L A Klein M Lang N Nash S L Kirschner 《Journal - Water Pollution Control Federation》1974,46(12):2653-2662
78.
79.
80.