首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   56篇
  免费   0篇
安全科学   4篇
废物处理   1篇
环保管理   5篇
综合类   2篇
基础理论   26篇
污染及防治   15篇
评价与监测   1篇
灾害及防治   2篇
  2023年   1篇
  2020年   2篇
  2019年   1篇
  2018年   3篇
  2017年   1篇
  2016年   2篇
  2015年   2篇
  2013年   7篇
  2012年   3篇
  2011年   4篇
  2010年   2篇
  2009年   7篇
  2008年   2篇
  2007年   2篇
  2006年   2篇
  2005年   4篇
  2004年   4篇
  2003年   1篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1994年   2篇
  1990年   1篇
排序方式: 共有56条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
Service quality in a construction technology laboratory can result in an improvement in construction companies’ competitiveness. This research aims to evaluate the service quality provided by a construction technology laboratory, specifically in the segment of performing testing through the rupturing of concrete samples. For this research, a survey was conducted using a structured questionnaire that was created based on a literature review regarding the surveying of laboratory customers at a university in the south of Brazil. Our research was both exploratory and quantitative, and the data were analyzed by applying multivariate data analysis. The conclusions of this study show that the dimensions of quality services are: communication, reliability, responsiveness, credibility, and tangibility. These five dimensions together provide a high explained variance standard of 79.75%. Having a suitable number of attendants available to serve customers and presenting agility in the construction laboratory is one of the managerial research contributions. Moreover, through information availability, this research generates greater traceability that can be used both by customers and by institutional management. Constantly and thoroughly monitoring the customer service cycle is another relevant factor that can improve the quality of the services provided.  相似文献   
46.
Surrogate species are used in standard toxicity tests for the environmental risk assessment of chemicals. Test results are then extrapolated to the situation in the field, which is often associated with a large degree of uncertainty. Since a vulnerable species in the field is not only characterised by its intrinsic sensitivity to a stressor but also by its potential for exposure and its population resilience, the identification of focal species based on these three components of vulnerability is needed for a more ecologically relevant risk assessment. This study listed European fish species that are susceptible to pesticide exposure in the field and thus achieved the first step towards identifying focal species for the risk assessment of pesticides for fish in Europe. A step-wise filtering approach was applied to list freshwater fish species that are native to Europe and widespread in the European Union, which inhabit streams, ditches or ponds in agricultural landscapes and therefore, are at an elevated risk of being exposed to pesticides. Out of the 579 fish species occurring in European freshwater, 27 species met the filtering criteria. The resulting list was verified based on monitoring studies that were conducted in agricultural landscapes over the past 20 years. Focal fish species that can be used for a more ecologically relevant environmental risk assessment of pesticides in Europe can be identified from the produced list of species by further assessing their ecological (life history and dispersal characteristics) and intrinsic sensitivities.  相似文献   
47.
The determination of arsenic compounds in algae collected on the Catalan coast (Western Mediterranean) is reported. Ten algae species and the seagrass Posidonia oceanica were analyzed. Total arsenic in the samples was determined by microwave digestion and inductively coupled plasma mass spectrometry (ICPMS). Arsenic speciation in water extracts of samples was analyzed by liquid chromatography with both anionic and cationic exchange with ICPMS detection (LC-ICPMS). The total arsenic content of the algae samples ranged from 2.96 to 39.0mg As kg(-1). The following compounds were detected: arsenite (As(III)), arsenate (As(V)), methylarsonate (MA), dimethylarsinate (DMA), sulfonate sugar (SO3-sug), sulfate sugar (SO4-sug), phosphate sugar (PO4-sug), arsenobetaine (AB), arsenocholine (AC), trimethylarsine oxide (TMAO) and glycerol sugar (Gly-sug). The main arsenic species found were arsenosugars. Significant percentages of arsenobetaine (0.54 mg As kg(-1), 28% of the extractable arsenic and 0.39 mg As kg(-1), 18% of the extractable arsenic) were found in Ulva rigida and Enteromorpha compressa. These results are discussed in relation to the presence of epiphytes.  相似文献   
48.
Abstract: We used experimental nests baited with California Quail (  Callipepla californica ) eggs or clay eggs to examine relative risks of nest predation in an agricultural landscape and in two large forest preserves in a south-temperate rainforest in Chile. The most common predators, as identified by marks on clay eggs, were a caracara (   Milvago chimango ), a blackbird ( Curaeus curaeus ), and rodents. Nest losses from predation were similar in large and small forest patches and lower in patches than in extensive forest. In general, predation risk was higher (and nest survival therefore lower) on forest edges than in forest interior, in short-grass pasture than in tall-grass pasture, in narrow corridors than in wide corridors, and on visible nests than on concealed nests. High predation risks in pasture habitat tended to increase the risk of nest predation in adjacent forest edges. For open-cup nesters, the risk of nest predation was relatively high in the present agricultural landscape, indicating that much of the available wooded habitat (  forest edges, narrow corridors) offers poor nesting habitat, although it may be suitable for foraging and traveling. The numerous bird-plant mutualisms in this landscape may be at risk if nesting success of the principal mutualists is consistently low.  相似文献   
49.
The substance class of inert organic-chemical stressors (IOCS) describes organic-chemical (macro-) molecules, which demonstrate a high level of persistence upon entry in the ecosystem, and whose degradation is limited. These synthetically produced organic-chemical macromolecules, which are often derived from the polymerization of different monomers, are, in the form of plastics, indispensable in the everyday world. They enter the environmental compartments and cause great damage due to primary (industry, cosmetic, washing of textile), and secondary (degradation) entry. If these particles get into aquatic systems, this has fatal consequences for the ecosystem such as the death of marine animals, or bioaccumulation. Wastewater treatment plants are reaching their limits and require innovative ideas for the sustainable removal of microplastic. This article examines a new approach to the removal of polymers from aquatic systems (lab scale) by using sol–gel induced agglomeration reactions to form larger particle agglomerates. These enlarged agglomerates can be separated much more easily from the wastewater, since they float on the water surface. Separation systems, e.g. sand trap can easily be used. A further advantage is that the agglomeration can be carried out completely independently of the type, size, and amount of the trace substance concentration as well as of the external influences (pH value, temperature, pressure). Thus, this new type of particle separation can not only be used in sewage treatment plants, but can also be transferred to decentralized systems (e.g. implementation in industrial processes).

Graphical Abstract

  相似文献   
50.
Social learning is a process suited to developing understanding and concerted action to tackle complex resource dilemmas, such as freshwater management. Research has begun to recognise that in practice social learning encounters a variety of institutional challenges from the shared habits and routines of stakeholders (organised by rules, norms and strategies) that are embedded in organisational structures and norms of professional behaviour. These institutional habits and routines influence the degree of willingness to engage with stakeholders, and expectations of behaviours in social learning processes. Considering this, there has been a call to understand how institutions influence social learning and emergent outcomes. We addresses this by presenting a heuristic for implementing social learning cognisant of institutional context to answer three questions: (i) How institutional influences impact implementation of social learning design; (ii) how implementation of social learning design modifies institutions influencing social learning; and (iii) how these changes in design and institutions together shape social learning outcomes? To answer these questions a freshwater planning exercise was designed, implemented and evaluated as a social learning process with community groups in two New Zealand catchments. Incorporating participatory reflection enabled the project team to modify social learning design to manage institutional influences hindering progress toward outcomes. Findings emphasise that social learning is underpinned by participants’ changing assumptions about what constitutes the institution of learning itself—from instruction to a dynamic, collective and emergent process. Reflecting on these assumptions also challenged participants’ expectations about their own and others’ behaviours and roles in freshwater planning.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号