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   40篇
  免费   0篇
安全科学   1篇
废物处理   3篇
环保管理   5篇
综合类   6篇
基础理论   6篇
污染及防治   13篇
评价与监测   2篇
社会与环境   4篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   1篇
  2014年   2篇
  2013年   4篇
  2012年   1篇
  2010年   3篇
  2009年   2篇
  2008年   3篇
  2007年   3篇
  2006年   1篇
  2005年   5篇
  2004年   4篇
  2003年   3篇
  2000年   1篇
  1992年   1篇
  1934年   1篇
排序方式: 共有40条查询结果,搜索用时 843 毫秒
21.
Environmental Chemistry Letters - Glyphosate is considered toxicologically harmful and presents potential association with human carcinogenesis and other chronic diseases, including mental and...  相似文献   
22.
The adoption of environmentally sustainable techniques by cooperatives and small companies results in specific difficulties rarely discussed in the literature. This paper describes an action-research carried out by seafood cultivators and university researchers in Guanabara Bay, which resulted in the substitution of the previous technique, based on extraction, by one without negative environmental impacts. The economic results have been satisfactory, so it can be expected that this activity may become more widespread in the region.  相似文献   
23.
The objective of this study was to examine postfire regeneration of tree, shrub, and dwarf shrub species, in relation to levels of damage in four planted pine forests (Pinus pinea, Pinus pinaster) in Andalusia. A prefire vegetation map was used for detailing species composition, vertical structure, and density and another for detailing the extent and intensity of fire damage. Between 3 and 7 years after the fires, an inventory was made of the vegetation in each area, using the step-point method. The information thus obtained was used to determine the amount of cover in the dwarf/shrub and tree layers, the frequency of species in each of the layers, floristic richness, and diversity (Shannon index). The botanical composition of the dwarf and shrub layer was analyzed using TWINSPAN. Variables were poorly correlated with level of fire damage, which suggests that the forests in this study followed the autosuccession model. Because of the artificial origin or seminatural condition, regeneration of the dominant tree species is poor, and it seems unlikely that forests will recover to their prefire state. Therefore action is recommended to restore these ecosystems.  相似文献   
24.
Two sulfonylurea herbicides, chlorsulfuron and metsulfuron-methyl, were studied under laboratory conditions, in order to elucidate the biodegradation pathway operated by Aspergillus niger, a common soil fungus, which is often involved in the degradation of xenobiotics. HPLC-UV was used to study the kinetic of degradation, whereas LC-MS was used to identify the metabolites structure. In order to avoid the chemical degradation induced by a decrease in pH, due to the production of citric acid by the fungus, the experiments were performed in a buffered neutral medium. No significant degradation for both compounds was observed in mineral medium with 0.2% sodium acetate. On the contrary, in a rich medium, after 28 days the degradations, chemical degradation excluded, were about 30% for chlorsulfuron and 33% for metsulfuron-methyl. The main microbial metabolites were obtained via cleavage of the sulfonylurea bridge. In addition the fungus seems to be able to hydroxylate the aromatic ring of chlorsulfuron. In the case of metsulfuron-methyl the only detected metabolite was the triazine derivative, while the aromatic portion was completely degraded. Finally, the demethylation of the methoxy group on the triazine ring, previously observed with a Pseudomonas fluorescens strain, was not observed with A. niger.  相似文献   
25.
Two salt marsh cores were collected from the Venice Lagoon, Italy, and analysed for PCDD/Fs. The samples were undisturbed and had an approximately constant accumulation rate. Radiochemical chronologies were established for the different core sections. The PCDD/F pattern in the surficial layers was very similar to that of atmospheric deposition measured in the same area. However, the pattern changed with increasing depth and was very different in the deeper sections, where the highest PCDD/F concentrations were measured. This layer was dated around the 1950s. Deeper layers have a profile similar to the surficial one. Undisturbed salt marsh cores appear to be a reliable tool for the reconstruction of temporal trends in the atmospheric deposition of persistent organic pollutants. It is proposed that the trends in the core reflect atmospheric deposition that probably results from the sum of two different contributions: emissions of the industrial district of Porto Marghera on the edge of the lagoon and the regional background.  相似文献   
26.
27.
28.
This study examines the extent to which human resource (HR) training (content and context) is contingent on business strategy (i.e. classified according to Miles and Snow (1984) typology—‘Designing strategic human resource systems’, Organizational Dynamics, 13 , 36–52) as well as the characteristics of the work process. Sixty‐five Spanish organizations (i.e. 65 senior executives and 65 senior HR officers) participated in the study. Using primarily factorial and cluster analyses, support was found to the assertion that companies adopting a particular type of training strategy/policy have a high degree of internal consistency amongst the training objectives sought. In terms of work processes and training, results indicate that under work processes where the content of work provides for enrichment and for long‐term results, companies tend to adopt training strategies where emphasis is on enhancement of individual specialized skills aimed at improving direct productivity. By contrast, firms who use work processes that are characterized by repetitive and routine tasks, de‐emphasize this type of training content. Results also indicae that limited level of contingencies exist between training policies and business strategy, especially when time dimension is also accounted for. While the theory suggests that organizations that have their HR training fit (contingent) on their business strategy are more effective, the empirical results portrayed in this study shows a more complex picture. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
29.
Climate change influence on POPs distribution and fate: a case study   总被引:2,自引:0,他引:2  
Climate change has the potential of affecting the behaviour and distribution of organic pollutants, including POPs. Direct effects of climate change, like temperature increase, modification of wind and precipitation patterns, sea level rise, snow and ice cover, may be very effective in altering the partitioning of POPs among the environmental compartments. Other consequences of future climate scenarios may imply the alteration of degradation rates, soil properties (and hence land use), air-particle partitioning of chemicals and so forth. A case study is here presented to illustrate the major implications of climate change on the long term at the local scale. A dynamic multimedia model was applied to selected PCB and PCDD/F congeners to simulate the effects of climate change on their distribution and fluxes over the next 50 y in the Venice Lagoon (Italy). Different climate change scenarios were tested, finding noticeable variations in POPs concentration even for minor environmental changes. PCBs and PCDFs environmental concentrations may differ by a factor two in a moderate climate change scenario, compared to a situation with stable climate over the next 50 y. However, model results also suggest that if global warming may have the potential of reducing the environmental levels of these chemicals, it would probably enhance their mobility and hence their potential for long range atmospheric transport.  相似文献   
30.
We propose the wildlife premium mechanism as an innovation to conserve endangered large vertebrates. The performance‐based payment scheme would allow stakeholders in lower‐income countries to generate revenue by recovering and maintaining threatened fauna that can also serve as umbrella species (i.e., species whose protection benefits other species with which they co‐occur). There are 3 possible options for applying the premium: option 1, embed premiums in a carbon payment; option 2, link premiums to a related carbon payment, but as independent and legally separate transactions; option 3, link premiums to noncarbon payments for conserving ecosystem services (PES). Each option presents advantages, such as incentive payments to improve livelihoods of rural poor who reside in or near areas harboring umbrella species, and challenges, such as the establishment of a subnational carbon credit scheme. In Kenya, Peru, and Nepal pilot premium projects are now underway or being finalized that largely follow option 1. The Kasigau (Kenya) project is the first voluntary carbon credit project to win approval from the 2 leading groups sanctioning such protocols and has already sold carbon credits totaling over $1.2 million since June 2011. A portion of the earnings is divided among community landowners and projects that support community members and has added over 350 jobs to the local economy. All 3 projects involve extensive community management because they occur on lands where locals hold the title or have a long‐term lease from the government. The monitoring, reporting, and verification required to make premium payments credible to investors include transparent methods for collecting data on key indices by trained community members and verification of their reporting by a biologist. A wildlife premium readiness fund would enable expansion of pilot programs needed to test options beyond those presented here. Mejora de la Conservación, Servicios del Ecosistema y Calidad de Vida Local Mediante un Mecanismo de Compensación de Vida Silvestre  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