全文获取类型
收费全文 | 404篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 22篇 |
环保管理 | 124篇 |
综合类 | 31篇 |
基础理论 | 98篇 |
污染及防治 | 87篇 |
评价与监测 | 27篇 |
社会与环境 | 10篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 5篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 31篇 |
2012年 | 10篇 |
2011年 | 19篇 |
2010年 | 16篇 |
2009年 | 15篇 |
2008年 | 26篇 |
2007年 | 26篇 |
2006年 | 22篇 |
2005年 | 15篇 |
2004年 | 16篇 |
2003年 | 20篇 |
2002年 | 17篇 |
2001年 | 17篇 |
2000年 | 13篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 4篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有420条查询结果,搜索用时 31 毫秒
411.
Representative Landscapes in the Forested Area of Canada 总被引:1,自引:0,他引:1
Canada is a large nation with forested ecosystems that occupy over 60% of the national land base, and knowledge of the patterns
of Canada’s land cover is important to proper environmental management of this vast resource. To this end, a circa 2000 Landsat-derived
land cover map of the forested ecosystems of Canada has created a new window into understanding the composition and configuration
of land cover patterns in forested Canada. Strategies for summarizing such large expanses of land cover are increasingly important,
as land managers work to study and preserve distinctive areas, as well as to identify representative examples of current land-cover
and land-use assemblages. Meanwhile, the development of extremely efficient clustering algorithms has become increasingly
important in the world of computer science, in which billions of pieces of information on the internet are continually sifted
for meaning for a vast variety of applications. One recently developed clustering algorithm quickly groups large numbers of
items of any type in a given data set while simultaneously selecting a representative—or “exemplar”—from each cluster. In
this context, the availability of both advanced data processing methods and a nationally available set of landscape metrics
presents an opportunity to identify sets of representative landscapes to better understand landscape pattern, variation, and
distribution across the forested area of Canada. In this research, we first identify and provide context for a small, interpretable
set of exemplar landscapes that objectively represent land cover in each of Canada’s ten forested ecozones. Then, we demonstrate
how this approach can be used to identify flagship and satellite long-term study areas inside and outside protected areas
in the province of Ontario. These applications aid our understanding of Canada’s forest while augmenting its management toolbox,
and may signal a broad range of applications for this versatile approach. 相似文献
412.
Mark Zappi Kenneth White Huey-Min Hwang Rakesh Bajpai Mohammad Qasim 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1818-1830
ABSTRACT In situ bioremediation is an innovative technique for the remediation of contaminated aquifers that involves the use of microorganisms to remediate soils and groundwaters polluted by hazardous substances. During its application, this process may require the addition of nutrients and/or electron acceptors to stimulate appropriate biological activity. Hydrogen peroxide has been commonly used as an oxygen source because of the limited concentrations of oxygen that can be transferred into the groundwater using above-ground aeration followed by reinjection of the oxygenated groundwater into the aquifer or subsurface air sparging of the aquifer. Because of several potential interactions of H2O2 with various aquifer material constituents, its decomposition may be too rapid, making effective introduction of the H2O2 into targeted treatment zones extremely difficult and costly. Therefore, a bench-scale study was conducted to determine the fate of H2O2 within subsurface aquifer environments. The purpose of this investigation was to identify those aquifer constituents, both biotic and abiotic, that are most active in controlling the fate of H2O2. The decomposition rates of H2O2 were determined using both equilibrated water samples and soil slurries. Results showed H2O2 decomposition to be effected by several commonly found inorganic soil components; however, biologically mediated catalytic reactions were determined to be the most substantial. 相似文献
413.
Hiroshi H. Saito T. Bond Calloway Jr. Daro M. Ferrara Alexander S. Chol Thomas L. White Luther V Glbson Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1242-1253
Abstract After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (<220 °C BP, >1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data. 相似文献
414.
Michael White Marilyn Gambone Haw Yen Prasad Daggupati Katrin Bieger Debjani Deb Jeff Arnold 《Journal of the American Water Resources Association》2016,52(1):269-274
The Soil and Water Assessment Tool (SWAT) is widely used in the United States (U.S.) to simulate hydrology and water quality simulation. Process‐based models like SWAT require a great deal of data to accurately represent the natural world, including topography, land use, soils, weather, and management. With the exception of management, all these data are available nationally from multiple sources. To date, credible SWAT studies in the U.S. have assembled suitable management data (operation scheduling, fertilization application rates, and plant growth parameterization). In this research, we develop a national management database for SWAT using existing U.S. Department of Agriculture data sources. These data are compatible with existing SWAT interfaces and are relatively easy to use. Although management data from local sources is preferred, these data are not always available. This work is intended to fill this void with more reasonable management data than the existing defaults. This national database covers all major cultivated crops and should facilitate improved SWAT applications in the U.S. These data were tested in two case studies and found to produce satisfactory SWAT predictions. The database developed in this research is freely available on the web. 相似文献
415.
Brett A. Bryan John Kandulu Daniel A. Deere Monique White Jacqueline Frizenschaf Neville D. Crossman 《Journal of environmental management》2009,90(10):3122-3134
Water-borne pathogens such as Cryptosporidium pose a significant human health risk and catchments provide the first critical pollution ‘barrier’ in mitigating risk in drinking water supply. In this paper we apply an adaptive management framework to mitigating Cryptosporidium risk in source water using a case study of the Myponga catchment in South Australia. Firstly, we evaluated the effectiveness of past water quality management programs in relation to the adoption of practices by landholders using a socio-economic survey of land use and management in the catchment. The impact of past management on the mitigation of Cryptosporidium risk in source water was also evaluated based on analysis of water quality monitoring data. Quantitative risk assessment was used in planning the next round of management in the adaptive cycle. Specifically, a pathogen budget model was used to identify the major remaining sources of Cryptosporidium in the catchment and estimate the mitigation impact of 30 alternative catchment management scenarios. Survey results show that earlier programs have resulted in the comprehensive adoption of best management practices by dairy farmers including exclusion of stock from watercourses and effluent management from 2000 to 2007. Whilst median Cryptosporidium concentrations in source water have decreased since 2004 they remain above target levels and put pressure on other barriers to mitigate risk, particularly the treatment plant. Non-dairy calves were identified as the major remaining source of Cryptosporidium in the Myponga catchment. The restriction of watercourse access of non-dairy calves could achieve a further reduction in Cryptosporidium export to the Myponga reservoir of around 90% from current levels. The adaptive management framework applied in this study was useful in guiding learning from past management, and in analysing, planning and refocussing the next round of catchment management strategies to achieve water quality targets. 相似文献
416.
White SH Duivenvoorden LJ Fabbro LD Eaglesham GK 《Environmental pollution (Barking, Essex : 1987)》2007,147(1):158-167
Cylindrospermopsis raciborskii is a cyanobacterium responsible for the production of the toxin, cylindrospermopsin (CYN). Tadpoles of the cane toad Bufo marinus were exposed to freeze-thawed whole cell extracts or live cultures of C. raciborskii containing maximum CYN concentrations of 400 microg L-1 or 232 microg L-1, respectively. Exposure to live culture treatment solutions resulted in up to 66% mortality of B. marinus, whereas tadpoles exposed to whole cell extracts containing similar toxin concentrations survived. Decreases in relative growth rates and time spent for swimming were recorded from tadpoles during both types of exposure regimes. Bioconcentration of CYN was not evident following exposure to whole cell extracts containing extracellular toxin. In contrast exposure to live cultures, which contained cell-bound toxin, resulted in maximum average tissue concentrations of 895 microg free-CYN kg-1 fresh weight. This is the first investigation of C. raciborskii exposure effects and toxin bioaccumulation in the developmental stages of an amphibian. 相似文献
417.
Sources, fate, and toxic hazards of oxygenated polycyclic aromatic hydrocarbons (PAHs) at PAH-contaminated sites 总被引:4,自引:0,他引:4
Lundstedt S White PA Lemieux CL Lynes KD Lambert IB Oberg L Haglund P Tysklind M 《Ambio》2007,36(6):475-485
In this paper we show that oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are important cocontaminants that should be taken into account during risk assessment and remediation of sites with high levels of PAHs. The presented data, which have been collected both from our own research and the published literature, demonstrate that oxy-PAHs are abundant but neglected contaminants at these sites. The oxy-PAHs show relatively high persistency and because they are formed through transformation of PAHs, their concentrations in the environment may even increase as the sites are remediated by methods that promote PAH degradation. Furthermore, we show that oxy-PAHs are toxic to both humans and the environment, although the toxicity seems to be manifested through other effects than those known to be important for polycyclic aromatic compounds in general, that is, mutagenicity and carcinogenicity. Finally, we present data that support the hypothesis that oxy-PAHs are more mobile in the environment than PAHs, due to their polarity, and thus have a higher tendency to spread from contaminated sites via surface water and groundwater. We believe that oxy-PAHs should be included in monitoring programs at PAH-contaminated sites, even if a number of other toxicologically relevant compounds that may also be present, such as nitro-PAHs and azaarenes, are not monitored. This is because oxy-PAH levels are difficult to predict from the PAH levels, because their environmental behavior differs substantially from that of PAHs, and oxy-PAHs may be formed as PAHs are degraded. 相似文献
418.
Chemicals present in domestic wastewater can adsorb to solid phase materials during sewage treatment. If biosolids (or sewage sludge) are applied to land, these chemicals can be transferred to soil. Under some circumstances they can also be transferred to surface waters during storm events either in solution or attached to sediment. In this paper we describe the utility of the SWAT 2000 model to estimate diffuse-source surface water exposure to "down-the-drain" chemicals. The model was applied hypothetically to predict the behaviour of linear alkylbenzene sulphonate (LAS), an anionic surfactant commonly used in household detergents, in a small catchment in Bedfordshire, UK, where it has previously been successfully validated for stream flow, sediments and pesticides. LAS transfers were estimated for two scenarios: (1) realistic and (2) reasonable worst case, based on assumptions on sludge application rates and the concentration of LAS in sludge. In addition, the sensitivity of the model output to the proportion of the catchment to which sludge is applied was established. Soil wetness and the total quantity of biosolids applied were the biggest determinants of chemical transport from the catchment. The potential of SWAT as a higher-tier tool in environmental risk assessments is discussed. 相似文献
419.
Two plant species, Cucurbita pepo and Cucurbita maxima, and two earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to soil and compost with equivalent p,p'-DDE contamination. Pollutant bioconcentration was equal in plant roots in both media, but translocation was higher in C. pepo. Bioaccumulation by E. fetida was approximately 6- and 3-fold higher than that by L. terrestris in the soil and compost, respectively. For all species, p,p'-DDE uptake was significantly greater from soil than from compost; 7- to 8-fold higher for plant roots and 3- to 7-fold higher for worms. Abiotic desorption from soil was approximately twice that from the compost. When all the data are normalized for organic-carbon content of the media, the contaminant is more tightly bound by soil than compost. Although the risk associated with p,p'-DDE is higher in soil than compost, important mechanistic differences exist in contaminant binding to organic carbon in the two media. 相似文献
420.
Aleah Bowie Wen Zhou Jingzhi Tan Philip White Tara Stoinski Yanjie Su Brian Hare 《Conservation biology》2022,36(4):e13922
Forests are essential common-pool resources. Understanding children's and adolescents’ motivations for conservation is critical to improving conservation education. In 2 experiments, we investigated 1086 school-aged children and adolescents (6–16 years old) from the United States, China, and the Democratic Republic of Congo. Testing participants in groups, we assessed their motivation for conservation based on collective-risk common-pool goods games in which they were threatened with losing their endowment unless the group donation exceeded a threshold needed to maintain the forest. Extrinsic motivations, rather than intrinsic, tended to lead to successful cooperation to maintain a forest. Certainty of losing individual payoffs significantly boosted successful cooperative conservation efforts across cultures (success rates were 90.63% and 74.19% in the 2 risk-extrinsic conditions, and 43.75% in the control condition). In U.S. participants, 2 extrinsic incentives, priming discussions of the value of forests and delay of payoffs as punishment, also increased success of cooperative conservation (success rates were 97.22% and 76.92% in the 2 extrinsic-incentive conditions, and 29.19% and 30.77% in the 2 control conditions). Conservation simulations, like those we used, may allow educators to encourage forest protection by leading groups to experience successful cooperation and the extrinsic incentives needed to motivate forest conservation. 相似文献