全文获取类型
收费全文 | 1082篇 |
免费 | 16篇 |
国内免费 | 21篇 |
专业分类
安全科学 | 34篇 |
废物处理 | 39篇 |
环保管理 | 238篇 |
综合类 | 131篇 |
基础理论 | 208篇 |
环境理论 | 2篇 |
污染及防治 | 364篇 |
评价与监测 | 66篇 |
社会与环境 | 33篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 8篇 |
2022年 | 14篇 |
2021年 | 20篇 |
2020年 | 5篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2017年 | 27篇 |
2016年 | 28篇 |
2015年 | 20篇 |
2014年 | 31篇 |
2013年 | 177篇 |
2012年 | 45篇 |
2011年 | 45篇 |
2010年 | 48篇 |
2009年 | 59篇 |
2008年 | 46篇 |
2007年 | 56篇 |
2006年 | 69篇 |
2005年 | 38篇 |
2004年 | 31篇 |
2003年 | 32篇 |
2002年 | 35篇 |
2001年 | 6篇 |
2000年 | 15篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 16篇 |
1996年 | 6篇 |
1995年 | 13篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1972年 | 7篇 |
1967年 | 4篇 |
排序方式: 共有1119条查询结果,搜索用时 15 毫秒
891.
Two aluminum water treatment residuals (Al-WTRs) from water treatment plants in Manatee County, FL and Punta Gorda, FL were evaluated as potential permeable reactive barrier (PRB) media to reduce groundwater phosphorus (P) losses. Short-term (<24 h) P sorption kinetics and long-term P sorption capacity were determined using batch equilibration studies. Phosphorus desorption was characterized following P loadings of 10, 20, 30, 40 and >70 g kg−1. Sorption and desorption studies were conducted on the <2.0 mm material and three size fractions within the <2.0 mm material. The effect of dissolved organic carbon (DOC) on P retention was determined by reacting Al-WTRs with P-spiked groundwater samples of varying initial DOC concentrations. Phosphorus sorption kinetics were rapid for all size fractions of both Al-WTRs (>98% P sorption effectiveness at shaking times ?2 h). The effect of DOC was minimal at <150 mg DOC L−1, but modest reductions (<22%) in P sorption effectiveness occurred at 587 mg DOC L−1. The P sorption capacities of the Manatee and Punta Gorda Al-WTRs (<2.0 mm) are ∼44 g kg−1 and >75 g kg−1, respectively, and the lifespan of an Al-WTR PRB is likely many decades. Desorption was minimal (<2% of the P sorbed) for cumulative P loadings <40 g kg-l, but increased (<9% of the P sorbed) at cumulative P loads >70 g kg−1. The <2.0 mm Manatee and Punta Gorda Al-WTRs are regarded as ideal PRB media for P remediation. 相似文献
892.
St George T Vlahos P Harner T Helm P Wilford B 《Environmental pollution (Barking, Essex : 1987)》2011,159(2):481-486
Improving methods for assessing the spatial and temporal resolution of organic compound concentrations in marine environments is important to the sustainable management of our coastal systems. Here we evaluate the use of ethylene vinyl acetate (EVA) as a candidate polymer for thin-film passive sampling in waters of marine environments. Log KEVA−W partition coefficients correlate well (r2 = 0.87) with Log KOW values for selected pesticides and polychlorinated biphenyls (PCBs) where Log KEVA−W = 1.04 Log KOW + 0.22. EVA is a suitable polymer for passive sampling due to both its high affinity for organic compounds and its ease of coating at sub-micron film thicknesses on various substrates. Twelve-day field deployments were effective in detecting target compounds with good precision making EVA a potential multi-media fugacity meter. 相似文献
893.
Evaluating Links Between Forest Harvest and Stream Temperature Threshold Exceedances: The Value of Spatial and Temporal Data
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jeremiah D. Groom Sherri L. Johnson Joshua D. Seeds George G. Ice 《Journal of the American Water Resources Association》2017,53(4):761-773
We present the results of a replicated before‐after‐control‐impact study on 33 streams to test the effectiveness of riparian rules for private and State forests at meeting temperature criteria in streams in western Oregon. Many states have established regulatory temperature thresholds, referred to as numeric criteria, to protect cold‐water fishes such as salmon and trout. We examined across‐year and within‐year patterns of exceedance at control and treatment stream temperature probes. Determining whether an exceedance at the downstream end of a harvest was unambiguously related to harvest proved surprisingly difficult. The likelihood of a site exceeding its numeric criterion appeared related, in part, to the site's preharvest temperature range. Four control reaches as well as three preharvest treatment reaches exceeded their numeric criteria, necessitating additional analysis to evaluate timber harvest impacts. Nine percent of sites (3 of 33) both exceeded their numeric criteria and exhibited a potential harvest effect (16.7% of private sites [3 of 18], 0% of State sites [0 of 15]). After harvest, exceedances were typically observed in only the first of the two post‐harvest years. These findings highlight the importance of including temporal and spatial controls in temperature assessments of numeric criteria when the assessment's purpose is to determine whether exceedances are related to human activities. 相似文献
894.
As the concept of sustainability broadens to include social aspects, sustainability organisations must embrace strategies that allow them to more effectively address community issues and procedural concerns. Biosphere reserves (BRs) and model forests (MFs) advocate strongly for community engagement to achieve place-based sustainability; in practice, however, these organisations have had variable success in effectively engaging community residents and addressing their needs and interests. In this paper, we offer a framework for place-based governance for sustainability that is used to compare strategies used in BRs and MFs operating in the Maritime Provinces of Canada with the operations of Vibrant Communities, an anti-poverty organisation that operates locally in Saint John, New Brunswick. We draw attention to three imperatives: comprehensive understanding, community empowerment, and community-based outcomes, and five procedural drivers: local leadership, strong networks, diverse community engagement, learning together, and information sharing. Based on our results, we provide greater clarity on processes that address the imperatives and mobilise the drivers of effective place-based governance for sustainability. Our results suggest that there is a need for theory and practice to advance beyond current understandings of sustainability governance to enhance the capacity of organisations seeking to implement community-based sustainability strategies. 相似文献
895.
George F. Antonious Eric T. Turley Mutari Abubakari John C. Snyder 《Journal of environmental science and health. Part. B》2017,52(4):251-255
The persistence and fate of chlorpyrifos and its two metabolites, chlorpyrifos-oxon and the 3, 5, 6-trichloro-2-pyridinol (TCP) break-down product were investigated on kale and collard leaves under field conditions. A simultaneous extraction and quantification procedure was developed for chrorpyrifos and its two main metabolites. Residues of chlorpyrifos, chlorpyrifos oxon, and TCP were determined using a gas chromatograph (GC) equipped with an electron capture detector (GC/ECD). Chlorpyrifos metabolites were detectable up to 23 days following application. Residues were confirmed using a GC equipped with a mass selective detector (GC/MSD) in total ion mode. Initial residues of chlorpyrifos were greater on collard (14.5 µg g?1) than kale (8.2 µg g?1) corresponding to half-lives (T1/2) values of 7.4 and 2.2 days, respectively. TCP, the hydrolysis product, was more persistent on collards with an estimated T1/2 of 6.5 days compared to kale (T1/2 of 1.9 days). 相似文献
896.
Consensus-based multi-stakeholder forms of environmental governance involving government, private and civil society actors, have become popular for advancing sustainability, but have been criticized for failing to achieve procedural justice objectives including recognition, participation and strengthening capabilities. Yet, how such models have functioned within non-governmental organizations dedicated to advancing sustainability has been underexplored. This paper assesses the procedural elements of consensus-based multi-stakeholder models used within Canadian biosphere reserves and model forests, two organizations working to address environment and sustainability issues. We draw on strategic documents and semi-structured interviews from five organizations in Canada to analyze their governance structures and processes against a framework for procedural justice. We find the organizational structure reproduces elitism and professionalism associated with stakeholder models more generally and reproduces challenges associated with recognition, participation and building capabilities found in other stakeholder approaches. Meeting broader sustainability challenges requires organizations to address procedural justice issues in addition to their traditional environmental concerns. 相似文献
897.
898.
899.
George Arnold Sc.D. E. Edgerley Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(4):235-237
The air basin between the Mississippi River and the bluff in Illinois is of particular interest for this report. The autumnal temperature profiles were measured by a wiresonde. Each day through September and October had an inversion at dawn and/or dusk. During the entire three months, inversions 5° or more occurred at dawn 64% of the mornings, those 10° or more occurred 45% of the mornings; and those 15° occurred 23% of the mornings. Under intense inversions, the topography holds cool air in the basin like water in a saucer, and currents within this 200-ft air layer comprise a quasi-closed circulation system. A frequent pattern of air circulation involves a northwestward surface drift in the basin, with a southwest wind aloft and an updraft over St. Louis. This forms a horizontal semi-vortex along the river, concentrating the heavier particulates near East St. Louis and Granite City. Multiple evidence showed this pattern to exist one morning among four. Business interests would use the basin for industrial expansion, but air resource planners prefer to keep new air pollution sources out of this low land. 相似文献
900.
George A. Jutze Richard J. Lewis 《Journal of the Air & Waste Management Association (1995)》2013,63(7):323-326
This paper describes a quality control technique used by the central headquarters operation of the Continuous Air Monitoring Program in an ejjort to insure valid data production from instruments located at remote sampling stations. The procedure consists of preparation of 0.10 to 2.00 ppm mixtures of SO2 or NO2 in duplicate Mylar bags, each encased in a corrugated paper box. These mixtures are analyzed during make-up to insure duplication. One box is shipped to the field station where it is analyzed on-site. The control mixture is analyzed in the central lab at the same time. Correlation between measurements indicates the usefulness of this dynamic calibration check. The techniques used are described and results of the program are presented. 相似文献