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   466篇
  免费   1篇
  国内免费   8篇
安全科学   8篇
废物处理   16篇
环保管理   33篇
综合类   128篇
基础理论   81篇
环境理论   2篇
污染及防治   153篇
评价与监测   27篇
社会与环境   24篇
灾害及防治   3篇
  2023年   7篇
  2022年   4篇
  2021年   19篇
  2020年   10篇
  2019年   6篇
  2018年   17篇
  2017年   17篇
  2016年   21篇
  2015年   15篇
  2014年   20篇
  2013年   34篇
  2012年   31篇
  2011年   36篇
  2010年   12篇
  2009年   22篇
  2008年   17篇
  2007年   31篇
  2006年   28篇
  2005年   19篇
  2004年   18篇
  2003年   25篇
  2002年   8篇
  2001年   11篇
  2000年   3篇
  1999年   1篇
  1998年   5篇
  1997年   2篇
  1995年   5篇
  1994年   4篇
  1993年   2篇
  1992年   1篇
  1990年   4篇
  1988年   1篇
  1984年   1篇
  1981年   1篇
  1979年   2篇
  1977年   1篇
  1975年   1篇
  1974年   2篇
  1967年   2篇
  1965年   1篇
  1962年   1篇
  1961年   2篇
  1957年   2篇
  1956年   2篇
  1954年   1篇
排序方式: 共有475条查询结果,搜索用时 15 毫秒
51.
Conservation and management of marine biodiversity depends on biomonitoring of marine habitats, but current approaches are resource-intensive and require different approaches for different organisms. Environmental DNA (eDNA) extracted from water samples is an efficient and versatile approach to detecting aquatic animals. In the ocean, eDNA composition reflects local fauna at fine spatial scales, but little is known about the effectiveness of eDNA-based monitoring of marine communities at larger scales. We investigated the potential of eDNA to characterize and distinguish marine communities at large spatial scales by comparing vertebrate species composition among marine habitats in Qatar, the Arabian Gulf (also known as the Persian Gulf), based on eDNA metabarcoding of seawater samples. We conducted species accumulation analyses to estimate how much of the vertebrate diversity we detected. We obtained eDNA sequences from a diverse assemblage of marine vertebrates, spanning 191 taxa in 73 families. These included rare and endangered species and covered 36% of the bony fish genera previously recorded in the Gulf. Sites of similar habitat type were also similar in eDNA composition. The species accumulation analyses showed that the number of sample replicates was insufficient for some sampling sites but suggested that a few hundred eDNA samples could potentially capture >90% of the marine vertebrate diversity in the study area. Our results confirm that seawater samples contain habitat-characteristic molecular signatures and that eDNA monitoring can efficiently cover vertebrate diversity at scales relevant to national and regional conservation and management.  相似文献   
52.
As part of the first environmental assessment within Montevideo Harbour, in summer and winter of 1998, sediments samples were collected at eight locations to determine the spatial distribution of anthropogenic pollutants. Muddy sediments with high organic matter content dominate the study area. Heavy metal levels indicated that sediments were highly polluted with Zn (overall mean: 312+/-102 microg g(-1) dry sediment), Pb (85+/-31), Cu (89+/-25), Cr (162+/-62), and Hg (0.63+/-0.3) and moderately with Ni (30+/-2) and Ag (1.2+/-0.4). Depending on location and season, aliphatic hydrocarbons reached from 21 to 120 microg g(-1), while the unresolved complex mixture represented up to 76% of the total aliphatic fraction. Total PAH concentrations ranged from 1.56 to 90.44 microg g(-1); except at one location, petroleum derivatives were identified as main local source. The results pointed out that almost all the harbour area presented some substances that can cause adverse biological effects, especially in the inner region where all metals are above PEL levels. Principal components analysis confirmed that the inner harbour region is most severely affected by the pollutants and it was possible to differentiate three regions according to their environmental quality.  相似文献   
53.
54.
55.
Riverine nutrient loads are among the major causes of eutrophication of the Baltic Sea. This study applied the Soil & Water Assessment Tool (SWAT) in three catchments flowing to the Baltic Sea, namely Vantaanjoki (Finland), Fyrisån (Sweden), and Słupia (Poland), to simulate the effectiveness of nutrient control measures included in the EU’s Water Framework Directive River Basin Management Plans (RBMPs). Moreover, we identified similar, coastal, middle-sized catchments to which conclusions from this study could be applicable. The first modelling scenario based on extrapolation of the existing trends affected the modelled nutrient loads by less than 5%. In the second scenario, measures included in RBMPs showed variable effectiveness, ranging from negligible for Słupia to 28% total P load reduction in Vantaanjoki. Adding spatially targeted measures to RBMPs (third scenario) would considerably improve their effectiveness in all three catchments for both total N and P, suggesting a need to adopt targeting more widely in the Baltic Sea countries.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01393-x) contains supplementary material, which is available to authorized users.  相似文献   
56.
Environmental Science and Pollution Research - Little is known about biosecurity measures and toxic effects during pesticide application in the province of Jujuy, Argentina, particularly concerning...  相似文献   
57.
58.
59.
We describe here a new type of method for isolation of rare cell populations in biological fluids. The method is based on the anthraquinone technology for covalent binding of molecules to a polymer surface. An anthraquinone molecule conjugated via a linker to an electrophilic group (AQ Immobilizer™ reagent, Exiqon A/S) is covalently bound to a polymer surface by UV irradiation. The electrophilic group of this AQ reagent can covalently bind a specific antibody directed against a specific cell marker. Applying a cell sample to the functional surface, the cells having the specific cell marker on the cell surface will bind to the antibody on the functional surface. Using this technique, even extremely small cell populations may be isolated. We succeeded in isolating fetal cells from maternal blood samples in the first trimester for chromosome defects genetic diagnosis. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
60.
This study deals with the German Federal Government’s approach of ensuring public support for its ‘Energiewende’, the swift and complete transition to an energy system based on renewable sources. First, the government’s ‘consensus management’ strategy is described as consisting of four elements: the setup of stakeholder deliberation fora; the funding of organisations dedicated to the public promotion of the energy transition; public campaigns that appeal to people’s commitment and the support of research on energy technologies. The study then traces the need for a strong social mandate of the energy transition back to the scope of the regulatory challenge and the recently growing conflicts around implementation, to institutional constraints of a consensus democracy and to the narrative of ‘Energiewende’ as the ‘grand national task’.  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