全文获取类型
收费全文 | 12306篇 |
免费 | 46篇 |
国内免费 | 336篇 |
专业分类
安全科学 | 134篇 |
废物处理 | 977篇 |
环保管理 | 1524篇 |
综合类 | 1567篇 |
基础理论 | 3558篇 |
环境理论 | 2篇 |
污染及防治 | 2685篇 |
评价与监测 | 1207篇 |
社会与环境 | 997篇 |
灾害及防治 | 37篇 |
出版年
2023年 | 21篇 |
2022年 | 66篇 |
2021年 | 61篇 |
2020年 | 23篇 |
2019年 | 66篇 |
2018年 | 1533篇 |
2017年 | 1427篇 |
2016年 | 1279篇 |
2015年 | 202篇 |
2014年 | 123篇 |
2013年 | 237篇 |
2012年 | 612篇 |
2011年 | 1507篇 |
2010年 | 812篇 |
2009年 | 752篇 |
2008年 | 1039篇 |
2007年 | 1393篇 |
2006年 | 175篇 |
2005年 | 159篇 |
2004年 | 160篇 |
2003年 | 185篇 |
2002年 | 222篇 |
2001年 | 95篇 |
2000年 | 75篇 |
1999年 | 48篇 |
1998年 | 47篇 |
1997年 | 41篇 |
1996年 | 32篇 |
1995年 | 28篇 |
1994年 | 33篇 |
1993年 | 26篇 |
1992年 | 14篇 |
1991年 | 24篇 |
1990年 | 11篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 18篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1978年 | 6篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
101.
102.
Many Superfund/hazardous chemical sites include waterbodies whose sediments contain hazardous chemicals. With the need to assess, rank, and remediate contaminated sediments at such sites, as well as in other waterways, regulators seek a simple, quantitative assessment approach that feeds easily into a decision‐making scheme. Numeric, co‐occurrence‐based “sediment quality guidelines” have emerged with the appearance of administrative simplicity. However, the very foundation of the co‐occurrence approach, based on the total concentrations of a chemical(s) in sediment, is technically invalid; its application relies on additional technically invalid presumptions. Use of technically invalid evaluation approaches renders any assessment of the significance of sediment contamination unreliable. This article reviews the technical roots and assumptions of the co‐occurrence‐based SQGs, the fundamental flaws in the rationale behind their development and application, and their misapplication for sediment quality evaluation. It also reviews concepts and approaches for the more reliable evaluation, ranking, and cleanup assessment of contaminated sediments at Superfund sites and elsewhere. © 2005 Wiley Periodicals, Inc. 相似文献
103.
A disturbing trend among governmental agencies is the remediation of so‐called “nonhazardous” contaminated sediments/soils by deposition in minimum‐design Subtitle D municipal solid waste (MSW) landfills or landfills with equivalent design. This is done despite the fact that, in terms of protection of public health and environmental quality, the designation “nonhazardous” is misleading at best, and the fact that minimum‐design Subtitle D landfills as being allowed will not ensure protection of groundwater quality for as long as the buried wastes remain a threat. Although acknowledged in the regulatory documentation and exposed in the writings of a few in the scientific/engineering community, the environmental and public health issues that will inevitably be faced at minimum‐design Subtitle D landfills are underplayed, and even misrepresented, to the public. Discussion of relevant issues, as well as remarkable omissions, characterized the October 2004 United States Army Corps of Engineers (US ACE)/United States Environmental Protection Agency (US EPA)/Sediment Management Work Group (SMWG) conference,” Addressing Uncertainty and Managing Risk at Contaminated Sediment Sites.” This article addresses many of those neglected issues. © 2005 Wiley Periodicals, Inc. 相似文献
104.
The shadow price of substitutable sulfur in the US electric power plant: a distance function approach 总被引:1,自引:0,他引:1
Lee M 《Journal of environmental management》2005,77(2):104-110
Given restrictions on sulfur dioxide emissions, a feasible long-run response could involve either an investment in improving boiler fuel-efficiency or a shift to a production process that is effective in removing sulfur dioxide. To allow for the possibility of substitution between sulfur and productive capital, we measure the shadow price of sulfur dioxide as the opportunity cost of lowering sulfur emissions in terms of forgone capital. The input distance function is estimated with data from 51 coal-fired US power units operating between 1977 and 1986. The indirect Morishima elasticities of substitution indicate that the substitutability of capital for sulfur is relatively high. The overall weighted average estimate of the shadow price of sulfur is -0.076 dollars per pound in constant 1976 dollars. 相似文献
105.
Lee Benda Marwan A. Hassan Michael Church Christine L. May 《Journal of the American Water Resources Association》2005,41(4):835-851
Headwater streams comprise 60 to 80 percent of the cumulative length of river networks. In hilly to mountainous terrain, they reflect a mix of hillslope and channel processes because of their close proximity to sediment source areas. Their morphology is an assemblage of residual soils, landslide deposits, wood, boulders, thin patches of poorly sorted alluvium, and stretches of bedrock. Longitudinal profiles of these channels are strongly influenced by steps created by sediment deposits, large wood, and boulders. Due to the combination of small drainage area, stepped shallow gradient, large roughness elements, and cohesive sediments, headwater streams typically transport little sediment or coarse wood debris by fluvial processes. Consequently, headwaters act as sediment reservoirs for periods spanning decades to centuries. The accumulated sediment and wood may be episodically evacuated by debris flows, debris floods, or gully erosion and transported to larger channels. In mountain environments, these processes deliver significant amounts of materials that form riverine habitats in larger channels. In managed steepland forests, accelerated rates of landslides and debris flows resulting from the harvest of headwater forests have the potential to seriously impact the morphology of headwater streams and downstream resources. 相似文献
106.
107.
Biochar physicochemical parameters as a result of feedstock material and pyrolysis temperature: predictable for the fate of biochar in soil? 总被引:1,自引:0,他引:1
108.
Nguyen Kim Nga Huynh Dang Chinh Phi Thi Thuy Hong Tran Quang Huy 《Journal of Polymers and the Environment》2017,25(2):146-155
This study aimed at finding effective strategies for high-performance removal of reactive blue 19 (RB19) dye from aqueous solution. Chitosan (CS) films had been prepared by using solvent casting with mild drying for this purpose. The CS films were characterized by X-ray diffraction, field-emission scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The performance of RB19 removal using CS were evaluated by varying contact time, solution pH, initial dye concentration, and adsorbent dosage. Adsorption isotherms, kinetics, and desorption were investigated by batch experiments. Results showed that CS films exhibited the optimal adsorption performance for RB19 removal and high maximum adsorption capacities of RB19, which were 799 and 822.4 mg g?1 at 20 and 40 °C, respectively. Adsorption kinetic data were well described by the pseudo-second-order kinetic model. FTIR analyses further indicated that interactions between RB19 and the CS film occurred during adsorption. The CS films also exhibited satisfactory desorption of RB19 at about 80 % after 30 min of desorption at pH 11. Our study demonstrated that the CS films can be easily prepared and applied for effective removal of RB19 in treatment of wastewater. 相似文献
109.
Christian Mougin Agnès Bouchez Laurence Denaix Isabelle Lamy François Laurent Fabrice Martin-Laurent Michel Mench 《Environmental science and pollution research international》2016,23(4):2974-2976
The fifth meeting of INRA’s national network of ecotoxicologists took place on 25 to 27 November 2014 in Biarritz, France. The main aim of the meeting was to bring together ecotoxicologists from INRA and associated partners, providing them ample opportunity to share and discuss their latest scientific results as well as the national policy of research in ecotoxicology and to precise perspectives for the network. 相似文献
110.