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排序方式: 共有193条查询结果,搜索用时 15 毫秒
31.
Kay D Wyer M Crowther J Stapleton C Bradford M McDonald A Greaves J Francis C Watkins J 《Water research》2005,39(16):3967-3981
The Ribble drainage basin is the single UK sentinel study area chosen for examining the implementation of the EU Water Framework Directive (WFD 20/60/EC). The study which has generated the data for this paper was initiated to quantify 'catchment-derived' fluxes of faecal indicators originating from both point and diffuse sources to inform the competent authorities on the potential for, and prioritization of, further options for reducing the faecal indicator loadings to this crucial coastal environment. It represents the first UK drainage basin-scale 'profile' of faecal indicator sources as recommended by WHO [1999. Health Based Monitoring of Recreational Waters: The Feasibility of a New Approach; the "Annapolis Protocol". World Health Organisation Geneva, Switzerland; 2003. Guidelines for Safe Recreational-Water Environments Volume 1: Coastal and Fresh-Waters. World Health Organisation Geneva, Switzerland] and incorporated into current drafts of the revised Bathing Water Directive [Anon, 2004. Council of the European Communities Amended proposal for a Directive of the European Parliament and of the Council concerning the management of bathing water quality. Brussels 23rd June]. This paper focuses on the relationships between land use and faecal indicator organism concentrations in surface waters within this very large drainage basin (1583 km2) containing some extensive urban areas. A geographical information system comprising readily available digital elevation, remotely sensed land cover and digital map data was used to generate the land use variables for subcatchments draining to 41 locations across the study area. Presumptive concentrations of coliforms, Escherichia coli and enterococci (colony forming unit (cfu) 100 ml(-1)) were measured at each location on at least 20 occasions over a 44-day period within the 2002 bathing season. The sampling programme targeted hydrograph events. Hydrometric records were used to allocate results as either base flow or high flow. At each site, geometric mean faecal indicator organism concentrations were significantly elevated at high flow compared to base flow. Stepwise regression modelling produced statistically significant models predicting geometric mean base and high-flow faecal indicator organism concentrations from land use variables (r2: 49.5-68.1%). The dominant predictor variable in each case was the proportion of built-up land in subcatchments, suggesting that this land use type, with associated sewage-related inputs, is a critical source of faecal indicator organisms in this drainage basin. 相似文献
32.
对目前国内外铬鞣废液的回收利用研究及方法进行了综述与比较,铬鞣废液的直接循环使用较回收铬的更易在制革厂实施。 相似文献
33.
Geller Josie; Brown Krista E.; Zaitsoff Shannon L.; Goodrich Shawna; Hastings Frances 《Canadian Metallurgical Quarterly》2003,34(4):406
Given that individuals with eating disorders, are typically ambivalent about changing their eating patterns, what approach is most helpful in working with this challenging group? This research compared the responses of clients with eating disorders and those of care providers to written clinical vignettes. All participants rated collaborative interventions as more acceptable and more likely to produce positive clinical outcomes than directive interventions. In addition, clients who were least ready for change rated directive interventions as less acceptable and less likely to produce adherence than did clients who were more ready. Despite participants' clear preference for collaborative interventions, directive interventions were rated as equally likely to occur. The implications of participant preferences and reasons that these preferences may not be reflected in actual clinical practice are addressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
34.
Fingerprinting Chamaesiphon populations as an approach to assess the quality of running waters
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Cyanobacterial communities are highly diverse in freshwaters and respond rapidly to changing environments. Previous studies have highlighted variations in the structure and composition of epilithic cyanobacterial communities in response to eutrophication in watercourses. In the present study, changes in benthic cyanobacterial communities from Guadalix River (Spain) biofilms were examined using temperature‐gradient gel electrophoresis (TGGE) in conjunction with microscopic examination of field‐fixed samples, focusing on populations of one of the dominant cyanobacteria: Chamaesiphon. Environmental characteristics were determined in order to characterize the trophic status of the sampling sites. The presence of cyanobacteria in the river was determined from complex TGGE patterns, band extraction, and subsequent sequencing of 16S rDNA gene fragments. The microscopic observations revealed that the unicellular genus Chamaesiphon and the filamentous genus Phormidium were dominant in the studied locations. Within the 2 genera, 4 Chamaesiphon populations were identified (Chamaesiphon fuscus, Chamaesiphon starmachii, Chamaesiphon subglobosus, and Chamaesiphon polymorphus) and Phormidium was represented at the sampling sites by the Phormidium autumnale morphotype. TGGE banding patterns differed among samplings sites as a function of water quality. The genetic analysis revealed 4 phylotypes within the genus Chamaesiphon and 1 phylotype within the classic P. autumnale clade. Chamaesiphon phylotypes were not equally distributed in all the sampling locations. Some phylotypes were related to low nutrient concentrations, while others were associated with eutrophic conditions. Our results support the use of fingerprints of Chamaesiphon populations obtained by TGGE to examine changes in water quality. 相似文献
35.
36.
An ecological perspective on a river’s rights: a recipe for more effective water quality governance?
Susanne Wuijts Jappe Beekman Bas van der Wal Cathy Suykens Peter P. J. Driessen Helena F. M. W. Van Rijswick 《国际水》2019,44(6-7):647-666
ABSTRACTIn several countries, the transfer of legal rights to rivers is being discussed as an approach for more effective water resources management. But what could this transfer mean in terms of a healthy river? We address this question by identifying the ecological requirements for naturally functioning rivers and then explore the demands which these requirements impose on society, the current policy responses to these requirements and whether the transfer of rights to the river could facilitate the preservation of healthy freshwater ecosystems. 相似文献
37.
本文对EPBD以及相关标准进行了简要介绍,并着重介绍标准EN15232。 相似文献
38.
Fernando Hernndez Sobrino Carlos Rodríguez Monroy 《Renewable & Sustainable Energy Reviews》2009,13(9):2675-2681
For more than a decade we have lived in a period where the so-called “sustainability” is crucial and is motivated primarily by the social awareness of achieving a balance between human development and the conservation of the environment. This philosophy has a direct and inevitable impact on business and politics. Governments have long since been developing standards and encouraging various diverse initiatives whose aim is to defend the environment.In recent times, the global debate on the environment has been centred on CO2 emissions. This gas is the major cause of the “greenhouse effect” and people are more concerned with the idea that the emissions of this gas should be minimized. As a result of this concern, the Kyoto Protocol was enacted and subscribed to by many countries, setting the maximum gas emissions for them.Fossil fuels are a major source of CO2 emissions. In 2003 the European Union (EU) directive 2003/30/EC [2003/30/EC Directive of the European Parliament and the Council—8th may 2003. On the promotion of the use of biofuels or other renewable fuels for transport] was developed with the aim of promoting the use of biofuels as a substitute for diesel or petrol among European Union countries as well as to contribute to fulfilling the commitments on climate change, security of supply in environmentally friendly conditions and the promotion of renewable energy sources.In order to achieve these goals, the directive forces all EU members to ensure that at least 5.75% of all petrol and diesel fuels sold for transport purposes are biofuels before December 31 of 2010. European Union countries have social and economic characteristics unique to themselves. The energy dependence from foreign sources, the features of the agricultural sector or the degree of industrialization varies greatly from one country to another. In this context, it is questionable whether the obligation imposed by this directive applies to achieve uniform and/or identical goals in each of the countries involved and whether the actions of the various governments are also aligned with these goals. 相似文献
39.
目的为解决线图形的圆弧矢量化中存在的不足,提高圆弧识别的精度.方法在基于动态步长跟踪直线算法的基础上,采用Bresenham的圆扫描算法生成跟踪路径,跟踪过程中如果发生偏离则动态调整圆弧参数继续跟踪,遵循"以特征指导跟踪"的思路.结果对GREC会议上给出的合成图片的测试结果优于现有算法,对测试的工程图纸的效果也优于当前的算法,识别精度有所提高,在交点处的识别效果较好.结论该算法能一次性整体识别出工程图纸中的圆弧或圆,抗干扰性较好. 相似文献
40.