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   290篇
  免费   0篇
  国内免费   1篇
安全科学   3篇
废物处理   7篇
环保管理   15篇
综合类   192篇
基础理论   23篇
污染及防治   34篇
评价与监测   4篇
社会与环境   13篇
  2022年   5篇
  2018年   9篇
  2015年   4篇
  2013年   7篇
  2012年   4篇
  2011年   3篇
  2010年   6篇
  2009年   7篇
  2008年   5篇
  2007年   5篇
  2006年   5篇
  2005年   4篇
  2004年   3篇
  2003年   4篇
  2002年   4篇
  2000年   4篇
  1999年   7篇
  1998年   7篇
  1994年   3篇
  1992年   5篇
  1985年   3篇
  1983年   3篇
  1982年   3篇
  1967年   3篇
  1963年   5篇
  1962年   8篇
  1961年   4篇
  1960年   6篇
  1959年   3篇
  1958年   9篇
  1957年   12篇
  1956年   13篇
  1955年   17篇
  1954年   6篇
  1953年   6篇
  1952年   4篇
  1950年   5篇
  1941年   2篇
  1939年   4篇
  1938年   4篇
  1937年   3篇
  1935年   5篇
  1933年   2篇
  1931年   3篇
  1930年   5篇
  1929年   3篇
  1924年   2篇
  1922年   2篇
  1920年   2篇
  1913年   3篇
排序方式: 共有291条查询结果,搜索用时 93 毫秒
191.
192.
193.
194.
195.
ABSTRACT

Northern coastal regions are facing multiple challenges from accelerating global environmental and socioeconomic changes, such as ecosystem degradation, climate change, intensified resource extraction, land use change and declining populations. Based on interviews with 13 farmers, fishers and aquaculture employees from coastal Nordland, northern Norway, this study demonstrates how the local stakeholders’ perceptions of change and experiences of vulnerability are closely linked to their livelihood values and worldviews. What the informants consider a sustainable and meaningful way of coastal living does not coincide with national goals for sustainable, natural resource dependent development of the region. The article demonstrates the importance of attending to local values if policymakers and managers are to ensure successful local mobilisation, reduce vulnerability to ongoing and future processes of change, and ensure legitimacy and consistency in development goals of coastal zone management. Insights from this study are useful for local and regional decision makers with responsibility for natural resource policies and development efforts.  相似文献   
196.
This paper attempts to replicate a safety climate model originally tested in Australia to assess its applicability in a different context: namely, across production workers in 22 medium-sized metal processing organizations in Austria. The model postulates that safety knowledge and safety motivation mediate the relation between safety climate on the one hand and safety compliance and participation on the other. Self-report data from 1075 employees were analyzed using structural equation modeling (SEM). The results of the replication study largely confirmed the original safety climate model. However, in addition to indirect effects, direct links between safety climate and actual safety behavior were found.  相似文献   
197.
198.
199.
200.
13C/12C stable carbon isotope fractionation was used to assess biodegradation in contaminated aquifers with toluene as a model compound. Different strains of anaerobic bacteria (Thauera aromatica, Geobacter metallireducens, and the sulfate-reducing strain TRM1) showed consistent 13C/12C carbon isotope fractionation with fractionation factors between C = 1.0017 and 1.0018. In contrast, three cultures of aerobic organisms, using different mono- and dioxygenase enzyme systems to initiate toluene degradation, showed variable isotope fractionation factors of C = 1.0027 (Pseudomonasputida strain mt-2), C = 1.0011 (Ralstonia picketii), andC = 1.0004 (Pseudomonas putida strain F1). The great variability of isotope fractionation between different aerobic bacterial strains suggests that interpretation of isotope data in oxic habitats can only be qualitative. A soil column was run as a model system for contaminated aquifers with toluene as the carbon source and sulfate as the electron acceptor and samples were taken at different ports along the column. Microbial toluene degradation was calculated based on the 13C/12C isotope fractionation factors of the batch culture experiments together with the observed 13C/12C isotope shifts of the residual toluene fractions. The calculated percentage of biodegradation, B, correlated well with the decreasing toluene concentrations at the sampling ports and indicated the increasing extent of biodegradation along the column. The theoretical toluene concentrations as calculated based on the isotope values matched the measured concentrations at the different sampling ports indicating that the Rayleigh equation can be used to calculate biodegradation in quasi closed systems based on measured isotope shifts. A similar attempt was performed to assess toluene degradation in a contaminated, anoxic aquifer. A transect of groundwater wells was monitored along the main direction of the groundwater flow and revealed decreasing concentrations accompanied with an increase in the 13C/12C stable carbon isotope ratio of the residual toluene. Calculation of the extent of biodegradation based on the isotope values and laboratory derived isotope fractionation factors showed that the residual toluene was degraded to more than 99% by microbial activity. Calculation of the theoretical residual toluene concentrations based on the measured isotope values described the strongly decreasing concentrations along the plume. Other aromatic hydrocarbons like benzene and naphthalene which were analysed in the same course also showed decreasing concentrations along the groundwater flow path accompanied by increasing 13C values indicating biodegradation.  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