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   712篇
  免费   5篇
  国内免费   13篇
安全科学   14篇
废物处理   70篇
环保管理   42篇
综合类   102篇
基础理论   145篇
污染及防治   248篇
评价与监测   78篇
社会与环境   29篇
灾害及防治   2篇
  2023年   14篇
  2022年   33篇
  2021年   33篇
  2020年   19篇
  2019年   11篇
  2018年   23篇
  2017年   24篇
  2016年   48篇
  2015年   26篇
  2014年   52篇
  2013年   68篇
  2012年   52篇
  2011年   62篇
  2010年   29篇
  2009年   38篇
  2008年   30篇
  2007年   43篇
  2006年   34篇
  2005年   16篇
  2004年   23篇
  2003年   13篇
  2002年   15篇
  2001年   2篇
  2000年   4篇
  1999年   4篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1992年   1篇
  1991年   1篇
  1988年   2篇
  1986年   2篇
  1983年   1篇
排序方式: 共有730条查询结果,搜索用时 15 毫秒
631.
632.
633.
The objective of this work was to manufacture biodegradable films by two different processes (casting and extrusion), from different combinations of cassava starch and xanthan gum. These films were produced by casting and by extrusion from six different starch-xanthan gum combinations (0, 2, 4, 6, 8 and 10% w/w), containing glycerol as plasticizer (20% w/w) and were also characterized according to their microstructure, optical, mechanical, and barrier properties. Scanning electron microscopy of the starch-xanthan gum extruded films showed reticulated surface and smooth interior, suggesting that xanthan was driven to the surface and gelatinized starch to the interior of the films during extrusion. Films manufactured by casting were entirely homogeneous. In general, casted films presented lower opacity and water vapor permeability and higher stress at break than films manufactured by extrusion. Xanthan gum addition affected mechanical properties of starch films, improving their stress and strain at break, especially for extruded samples, but these properties did not show stability at different RH conditions.  相似文献   
634.
The relationship between media and the construction of environmental policy has been studied acutely in the Global North. However, less attention has been paid to deeper cultural symbols displayed in public policy discussions in the Global South. Through qualitative examination of 100 letters to the editor (LTE) of the Chilean newspaper, El Mercurio, this study examined the imaginaries in the public discussion of the Native Forest Policy in Chile. Although such a discussion was often framed as a technical debate, the letters to El Mercurio were embedded within Catholic imaginaries, condensed into two main sets. The first one constructed forests as endangered due to human action and called for immediate protection, contending that humans shall not destroy God's creation. The second set depicted a degraded forest in need of rational management to satisfy the needs of God's children. This study suggests that, in a mediated public discussion, religion might play an important role in communicating environmental issues. This work contributes to our understanding of environmental imaginaries and discourses in the context of environmental controversies, to the understanding of the functions of the LTE, and to the social construction of forest policy in recent post-autocratic regimes.  相似文献   
635.

Background, aim and scope  

The Pego-Oliva Marsh is the second most important wetland in the Valencian Community (Spain). It is included in the RAMSAR agreement and represents one key point for migratory birds. Emerging contaminants from the human pressure, such as pharmaceuticals, illicit drugs and personal care product, are not included in the list of priority contaminants of the Water Framework Directive yet, and are neither monitored nor controlled. However, pollution of emerging contaminants can threaten the environment and even human health. In order to understand the status of the emerging contamination and recommend future rationalization of countermeasures, the occurrence of illicit drugs was investigated.  相似文献   
636.

Purpose  

Perfluorinated compounds (PFCs) are widely distributed from industrialized to remote locations throughout the world. This study demonstrates the spatial distributions of PFCs in water and sediments from the L’Albufera Natural Park (Valencia, Spain).  相似文献   
637.
Depending on the modifications proposed, chitosan films present different characteristics, for instance correlated to hydrophilicity, chemical and mechanical properties. The aim of this study was to evaluate the influence of glutaraldehyde crosslinking and an alkaline post-treatment with NaOH on the characteristics of chitosan based films. Films were obtained by casting and characterized by thickness, swelling degree, mechanical and thermal properties and chemical structure. The water vapor permeability (WVP) was also evaluated for food packaging application. It was observed that crosslinking and NaOH post-treatment have great influence on the chitosan films characteristics. Crosslinking reduced the swelling degree of films and increased its fragility, whereas NaOH treatment also reduces the swelling degree and changes mechanical properties, acting in the same way as a crosslinker. The WVP analyses showed that the basic treatment could substitute the glutaraldehyde crosslinking for film water stability, without greatly compromising the barrier properties of chitosan based films.  相似文献   
638.

Background, aim, and scope  

Olive oil mill wastewater (OOMW) environmental impacts minimization have been attempted by developing more effective processes, but no chemical or biological treatments were found to be totally effective to mitigate their impact on receiving systems. This work is the first that reports simultaneously the efficiency of three different approaches: biological treatment by two fungal species (Trametes versicolor or Pleurotus sajor caju), enzymatic treatment by laccase, and chemical treatment by photo-Fenton oxidation on phenols removal.  相似文献   
639.
Environmental Science and Pollution Research - In this study, we report the potential of 2D/2D TiO2-GO-ZnFe2O4 photocatalyst obtained using the fluorine-free lyophilization technique for the...  相似文献   
640.
Journal of Material Cycles and Waste Management - This paper reports the development and characterization of new ceramics from hazardous bauxite red mud (50...  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