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   112篇
  免费   3篇
废物处理   5篇
环保管理   13篇
综合类   20篇
基础理论   16篇
环境理论   1篇
污染及防治   47篇
评价与监测   7篇
社会与环境   5篇
灾害及防治   1篇
  2023年   1篇
  2022年   3篇
  2021年   1篇
  2020年   3篇
  2019年   5篇
  2018年   5篇
  2017年   4篇
  2016年   7篇
  2015年   11篇
  2014年   6篇
  2013年   2篇
  2012年   7篇
  2011年   4篇
  2010年   4篇
  2009年   7篇
  2008年   13篇
  2007年   6篇
  2006年   7篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2002年   1篇
  2001年   2篇
  2000年   1篇
  1995年   2篇
  1991年   3篇
  1967年   1篇
  1959年   1篇
  1957年   1篇
  1955年   1篇
  1929年   1篇
排序方式: 共有115条查询结果,搜索用时 15 毫秒
21.
22.
As natural resource management agencies and conservation organizations seek guidance on responding to climate change, myriad potential actions and strategies have been proposed for increasing the long-term viability of some attributes of natural systems. Managers need practical tools for selecting among these actions and strategies to develop a tailored management approach for specific targets at a given location. We developed and present one such tool, the participatory Adaptation for Conservation Targets (ACT) framework, which considers the effects of climate change in the development of management actions for particular species, ecosystems and ecological functions. Our framework is based on the premise that effective adaptation of management to climate change can rely on local knowledge of an ecosystem and does not necessarily require detailed projections of climate change or its effects. We illustrate the ACT framework by applying it to an ecological function in the Greater Yellowstone Ecosystem (Montana, Wyoming, and Idaho, USA)-water flows in the upper Yellowstone River. We suggest that the ACT framework is a practical tool for initiating adaptation planning, and for generating and communicating specific management interventions given an increasingly altered, yet uncertain, climate.  相似文献   
23.
24.
25.
Hulvey KB  Zavaleta ES 《Ecology》2012,93(2):378-388
The effects of declining plant biodiversity on ecosystem processes are well studied, with most investigations examining the role of species richness declines rather than declines of species abundance. Using grassland mesocosms, we examined how the abundance of a native, resident species, Hemizonia congesta (hayfield tarweed), affected exotic Centaurea solstitialis (yellow starthistle) invasion. We found that progressive H. congesta abundance declines had threshold effects on invasion resistance, with initial declines resulting in minor increases in invasion and subsequent declines leading to accelerating increases in invader performance. Reduced invasion resistance was explained by increased resource availability as H. congesta declined. We also found evidence that resident abundance might indirectly affect invasion by mediating invader impact on resident competitors; C. solstitialis disproportionately reduced H. congesta biomass in low-abundance rather than high-abundance populations. H. congesta's direct and indirect effects on invasion resistance illustrate that an individual species' declining abundance can have accelerating, deleterious effects on ecosystem functions of conservation value.  相似文献   
26.
27.
Journal of Polymers and the Environment - The search for a straightforward technology for post-consumer poly(ethylene terephthalate) (PC-PET) degradation is essential to develop a circular economy....  相似文献   
28.
Important reactive minerals are commonly created during in situ groundwater remediation activities; for example, iron sulfides formed during enhanced reduction approaches can abiotically degrade many chlorinated solvents. However, cost-effective tools to evaluate these treatment processes in field applications are limited and the collection of samples to evaluate in situ mineral formation is costly due to drilling requirements. The new passive Min-Trap sampler is a simple and cost-effective tool that can directly measure the formation of reactive minerals in situ without the need for additional drilling or soil core collection. The methods presented here describe how Min-Traps deployed in conventional monitoring wells can measure reactive minerals and how these minerals can be identified through commercially available analytical methods. Several examples are presented that show how Min-Traps can be used to characterize the rate and spatial variability of reactive mineral precipitation and these data may support operation and optimization decisions.  相似文献   
29.
Das Stabilit?tsverhalten von H+-, NH 4 + -und PO 4 3− -Ionen in Niederschlagsproben wurde unter verschiedenen Lagerungs-und Transportbedingungen untersucht. Ursachen für Ver?nderungen sind sowohlmikrobiologische als auchphysikalisch-chemische Prozesse. Die Unterdrückung mikrobieller Aktivit?ten gelingt im Rahmen vonDepositionsme?netzen mit konventioneller na?chemischer Analytik am besten durch Zusatz von Silberchloridpulver und gleichzeitiger Kühlung bei +4°C. Konzentrationsmessungen von unbehandelten Niederschlagsproben mit l?ngeren Expositions-und Transportzeiten müssen kritisch betrachtet werden.  相似文献   
30.
Concern regarding the impacts of continued nitrogen and sulfur deposition on ecosystem health has prompted the development of critical acid load assessments for forest soils. A critical acid load is a quantitative estimate of exposure to one or more pollutants at or above which harmful acidification-related effects on sensitive elements of the environment occur. A pollutant load in excess of a critical acid load is termed exceedance. This study combined a simple mass balance equation with national-scale databases to estimate critical acid load and exceedance for forest soils at a 1-km(2) spatial resolution across the conterminous US. This study estimated that about 15% of US forest soils are in exceedance of their critical acid load by more than 250eqha(-1)yr(-1), including much of New England and West Virginia. Very few areas of exceedance were predicted in the western US.  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