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   368篇
  免费   2篇
  国内免费   6篇
安全科学   12篇
废物处理   30篇
环保管理   35篇
综合类   43篇
基础理论   74篇
环境理论   3篇
污染及防治   132篇
评价与监测   25篇
社会与环境   20篇
灾害及防治   2篇
  2023年   5篇
  2022年   18篇
  2021年   16篇
  2020年   3篇
  2019年   10篇
  2018年   16篇
  2017年   19篇
  2016年   18篇
  2015年   7篇
  2014年   23篇
  2013年   33篇
  2012年   23篇
  2011年   35篇
  2010年   18篇
  2009年   12篇
  2008年   20篇
  2007年   19篇
  2006年   17篇
  2005年   11篇
  2004年   7篇
  2003年   10篇
  2002年   8篇
  2001年   1篇
  2000年   2篇
  1999年   4篇
  1998年   2篇
  1997年   1篇
  1996年   4篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1986年   1篇
  1981年   1篇
  1958年   1篇
  1956年   1篇
排序方式: 共有376条查询结果,搜索用时 0 毫秒
371.
While a small set of economic activities generates most of the direct environmental burdens, the complexity of connections within an economic system requires consideration of the effects caused by the interdependences between its different agents. To date, however, the input–output (I–O) subsystems literature has been limited to uncovering the intersectoral linkages of direct and indirect environmental impacts within an economy and the connections between sectors and private consumption have thus not attracted much attention. This paper proposes an I–O subsystems model that endogenously incorporates not only production sectors but also household consumption to capture the entire channel of environmental impacts. The empirical application focuses on carbon dioxide equivalent (CO2-eq.) emissions and water use associated with production sectors and households defined in the I–O table for a Spanish region, Extremadura. The results highlight the key role of the effects induced by private consumption on the environmental burdens of services.  相似文献   
372.
Exposure measurements of concentrations that are non-detectable or near the detection limit (DL) are common in environmental research. Proper statistical treatment of non-detects is critical to avoid bias and unnecessary loss of information. In the present work, we present an overview of possible statistical strategies for handling non-detectable values, including deletion, simple substitution, distributional methods, and distribution-based imputation. Simple substitution methods (e.g., substituting 0, DL/2, DL/ radical2, or DL for the non-detects) are the most commonly applied, even though the EPA Guidance for Data Quality Assessment discouraged their use when the percentage of non-detects is >15%. Distribution-based multiple imputation methods, also known as robust or "fill-in" procedures, may produce dependable results even when 50-70% of the observations are non-detects and can be performed using commonly available statistical software. Any statistical analysis can be conducted on the imputed datasets. Results properly reflect the presence of non-detectable values and produce valid statistical inference. We describe the use of distribution-based multiple imputation in a recent investigation conducted on subjects from the Seveso population exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in which 55.6% of plasma TCDD measurements were non-detects. We suggest that distribution-based multiple imputation be the preferred method to analyze environmental data when substantial proportions of observations are non-detects.  相似文献   
373.
The ability of Pseudomonas aeruginosa ATCC 27853 to grow and synthesize polyhydroxyalkanoates (PHAs) using Tween 20 as the sole carbon source was investigated. Tween 20 could support cell growth and PHA production. The polymer produced from Tween 20 was compared with those produced from its major free fatty acids components: lauric (C12), myristic (C14), and palmitic (C16) acids. Gas-chromatographic analysis of methanolyzed samples and 13C-Nuclear Magnetic Resonance (NMR) showed that the PHAs obtained are composed of even carbon atoms 3-hydroxyalkanoates ranging from C6 to C14, with C8 and C10 as the predominant components. The nature of the carbon sources used had little influence on the composition, but was found to be important in determining the average molecular weight, shorter chain fatty acids yielding higher molecular weight products. Fast Atom Bombardment-Mass Spectrometry (FAB-MS) of partially pyrolyzed samples, coupled to statistical analysis, showed that these PHAs are random copolymers.  相似文献   
374.
Decision makers interested in promoting sustainable development must simultaneously consider the environmental, economic and social implications of any action. This article proposes the Framework for Integrated Sustainability Assessment (FISA), a methodological framework for conducting a sustainability impact assessment of any investment project. Based on a Multiregional Input–Output (MRIO) framework, FISA links the extended MRIO results with social risk data from the Social Hotspots Database (SHDB) in order to integrate the social with the environmental and economic pillars. Resulting impacts are simultaneously considered and reported by means of FISA charts, making it possible to assess the different impacts within the three sustainability pillars across countries involved in the whole supply chain of investment projects. This methodological framework can be applied not only to compare the sustainability impacts of two alternative projects, but also to derive specific recommendations aimed at minimizing the harmful social, environmental and economic effects along the whole project supply chain.  相似文献   
375.
Environmental Science and Pollution Research - A biocomposite system was developed and tested for the removal of the azo dye Reactive Red (RR195) from wastewater. The biocomposite was synthesized...  相似文献   
376.
International regulation of the emission of acidic sulphur and nitrogen oxides from commercial shipping has focused on the risks to human health, with little attention paid to the consequences for the marine environment. The introduction of stricter regulations in northern Europe has led to substantial investment in scrubbers that absorb the sulphur oxides in a counterflow of seawater. This paper examines the consequences of smokestack and scrubber release of acidic oxides in the Baltic Sea according to a range of scenarios for the coming decades. While shipping is projected to become a major source of strong acid deposition to the Baltic Sea by 2050, the long-term effect on the pH and alkalinity is projected to be significantly smaller than estimated from previous scoping studies. A significant contribution to this difference is the efficient export of surface water acidification to the North Sea on a timescale of 15–20 years.  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