全文获取类型
收费全文 | 319篇 |
免费 | 2篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 10篇 |
废物处理 | 19篇 |
环保管理 | 77篇 |
综合类 | 31篇 |
基础理论 | 93篇 |
污染及防治 | 70篇 |
评价与监测 | 12篇 |
社会与环境 | 15篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 10篇 |
2014年 | 4篇 |
2013年 | 31篇 |
2012年 | 16篇 |
2011年 | 26篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 22篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 21篇 |
2001年 | 13篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 1篇 |
1995年 | 6篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1973年 | 3篇 |
1966年 | 1篇 |
排序方式: 共有328条查询结果,搜索用时 171 毫秒
91.
92.
Francis C. Ezeonu 《The Environmentalist》2001,21(4):259-263
Environmental fluctuations and biological variability affect the establishment of baseline data in studying the ecotoxic effects of pollutants. Since substantial fluctuations are recorded for various ecological indices, it becomes problematic to establish whether an observed change in some ecological parameters represents a variation caused by presence of a pollutant, or represents 'natural' fluctuations inherent in the ecosystem.Thus, ability to predict ecotoxic effect lies at the base of the diagnosis. Such diagnosis should employ characteristics that reflect the integrated response of component populations to perturbations and as well provide a comprehensive picture of ecosystem 'status'. Measurements become authentic and acceptable only when compared with normal values of the numerical parameter in question. 相似文献
93.
94.
95.
The fate of aromatic amines in natural systems is important to understand due to the persistence and toxicity of these chemicals. Laboratory experiments were performed to elucidate aniline and benzidine behavior in silty-clay, sandy loam, and sandy soils, and six background matrices (rainwater, 12.5 mM CaCl(2), 25 mM CaCl(2), and each passed through soil columns). The goals of this study were to test the validity of using CaCl(2) as a laboratory simulation for rainwater and to observe how short-term sorption (24 h) of aniline and benzidine changed when these solutions were passed through soil columns. Results indicated that neither CaCl(2) solution exactly predicted the sorption of these chemicals in corresponding rainwater solutions, likely due to varying soil properties that influenced the sorption mechanisms. Statistical analyses revealed that the passage of rainwater or CaCl(2) solutions through soil columns did not significantly affect the sorption of aniline or benzidine. Cation exchange and solubility plots were created to identify the sorption mechanisms taking place in the short-term batch experiments. These plots indicated that cation exchange played a role in the sorption of both aniline and benzidine under all conditions, while solubility plots showed higher correlations for benzidine, a consequence of its lower aqueous solubility. 相似文献
96.
Francis E. Putz 《Conservation biology》2005,19(3):978-979
97.
Methane fluxes from artificial wetlands: A global appraisal 总被引:1,自引:0,他引:1
Methane emissions make an important contribution to the enhanced greenhouse effect, emissions from rice growing being one
of its major anthropogenic sources. The estimation of global fluxes of methane from rice and from coarse fiber production
depends on extrapolating observed data across countries and agroclimatic zones: the estimates are therefore imprecise. We
present a revised estimate of global emissions of 96 Tg CH4/yr, given 1991 rice areas, and 1991 production data for those tropical coarse fibers that also produce methane under anaerobic
conditions. This is higher than many previous studies, which systematically underestimated the fluxes from tropical countries.
As the world's population increases, the demand for rice will rise. This demand can only be satisfied through greater rice
production, either by bringing new areas into rice growing or by using the present area more intensively. Strategies based
on improved water management and fertilizer use will allow increased rice production and yields and reduce the methane flux
per unit or rice production. 相似文献
98.
Francis D. Heliotis Calvin B. DeWitt 《Journal of the American Water Resources Association》1987,23(6):1011-1016
ABSTRACT: Two types of rapid water table responses to rain were observed in a northern Michigan peatland. The first, called the Lisse effect, occurred during rains of high intensity when the infiltrating water acted as a tightly closing lid that forced the water table to rise to the level required to compensate for the pressure increase. The second, called the Wieringermeer effect, was a rapid rise of the water table to the surface due to the conversion of capillary to phreatic water and was always followed by an equally rapid decline after cessation of the rainfall. We simulated these phenomena in the laboratory and estimated the critical parameters that determine their occurrence. The recognition of the importance of the capillary fringe is essential in evaluating the role of wetlands in flood control and in wastewater treatment. 相似文献
99.
Hurricane Katrina‐linked environmental injustice: race,class, and place differentials in attitudes 下载免费PDF全文
Claims of environmental injustice, human neglect, and racism dominated the popular and academic literature after Hurricane Katrina struck the United States in August 2005. A systematic analysis of environmental injustice from the perspective of the survivors remains scanty or nonexistent. This paper presents, therefore, a systematic empirical analysis of the key determinants of Katrina‐induced environmental injustice attitudes among survivors in severely affected parishes (counties) in Louisiana and Mississippi three years into the recovery process. Statistical models based on a random sample of survivors were estimated, with the results revealing significant predictors such as age, children in household under 18, education, homeownership, and race. The results further indicate that African‐Americans were more likely to perceive environmental injustice following Katrina than their white counterparts. Indeed, the investigation reveals that there are substantial racial gaps in measures of environmental injustice. The theoretical, methodological, and applied policy implications of these findings are discussed. 相似文献
100.
Di Li Swati Yewalkar Xiaotao Bi Sheldon Duff Dusko Posarac Heli Wang Layne A. Woodfin Jan-Hendrik Hehemann Sheila C. Potter Francis E. Nano 《Frontiers of Environmental Science & Engineering》2017,11(2):9
The gene for the catalytic domain of thermostable endo-β-1,3-glucanase (laminarinase) LamA was cloned from Thermotoga maritima MSB8 and heterologously expressed in a bioengineered Synechococcus sp. PCC 7002. The mutant strain was cultured in a photobioreactor to assess biomass yield, recombinant laminarinase activity, and CO2 uptake. The maximum enzyme activity was observed at a pH of 8.0 and a temperature of 70°C. At a CO2 concentration of 5%, we obtained a maximum specific growth rate of 0.083 h–1, a biomass productivity of 0.42 g?L–1?d–1, a biomass concentration of 3.697 g?L–1, and a specific enzyme activity of the mutant strain of 4.325 U?mg–1 dry mass. All parameters decreased as CO2 concentration increased from 5% to 10% and further to 15% CO2, except enzyme activity, which increased from 5% to 10% CO2. However, the mutant culture still grew at 15% CO2 concentration, as reflected by the biomass productivity (0.26 g?L–1?d–1), biomass concentration (2.416 g?L–1), and specific enzyme activity (3.247 U?mg–1 dry mass).
相似文献