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   246篇
  免费   0篇
  国内免费   1篇
安全科学   16篇
废物处理   7篇
环保管理   13篇
综合类   16篇
基础理论   30篇
污染及防治   128篇
评价与监测   8篇
社会与环境   27篇
灾害及防治   2篇
  2022年   4篇
  2021年   3篇
  2020年   1篇
  2019年   5篇
  2018年   1篇
  2017年   4篇
  2016年   7篇
  2015年   16篇
  2014年   7篇
  2013年   14篇
  2012年   12篇
  2011年   12篇
  2010年   6篇
  2009年   12篇
  2008年   13篇
  2007年   11篇
  2006年   17篇
  2005年   18篇
  2004年   10篇
  2003年   5篇
  2002年   6篇
  2001年   7篇
  2000年   2篇
  1999年   2篇
  1998年   5篇
  1997年   4篇
  1996年   3篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1992年   2篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1982年   3篇
  1981年   6篇
  1980年   1篇
  1979年   2篇
  1977年   5篇
  1976年   3篇
  1956年   1篇
排序方式: 共有247条查询结果,搜索用时 46 毫秒
91.
We present a multi-model ensemble study for the Baltic Sea, and investigate the combined impact of changing climate, external nutrient supply, and fisheries on the marine ecosystem. The applied regional climate system model contains state-of-the-art component models for the atmosphere, sea ice, ocean, land surface, terrestrial and marine biogeochemistry, and marine food-web. Time-dependent scenario simulations for the period 1960–2100 are performed and uncertainties of future projections are estimated. In addition, reconstructions since 1850 are carried out to evaluate the models sensitivity to external stressors on long time scales. Information from scenario simulations are used to support decision-makers and stakeholders and to raise awareness of climate change, environmental problems, and possible abatement strategies among the general public using geovisualization. It is concluded that the study results are relevant for the Baltic Sea Action Plan of the Helsinki Commission.  相似文献   
92.
The Swedish System for Quality Assessment of Agricultural Soils   总被引:2,自引:0,他引:2  
Soil quality assessment is based on the concept of soilfunctions. The performances of three soil functions, cropproduction, biological decomposition and matter exchange withthe atmosphere and groundwater, are used as quality criteria.Soil properties that can be used as indicators for the degreeof functional performance were identified. Each soil propertyselected was graded into five classes – from best (class 1) toworst (class 5). Grading was based biological on boundaryconditions as well as on statistical distribution. The systemoutlined can be used to interpret the quality state ofagricultural soils, provides for a relative comparison betweensoils, and may be helpful in an environmental monitoringprogram to assess trends in data.  相似文献   
93.
This article analyzes how electronic waste (e-waste) gets represented in television news stories. The main objective is to present a perspective on how a “low-frequency” emergency (i.e. a lengthy and ongoing state of environmental emergency) is presented as a newsworthy issue. Drawing on literature on televised “distant suffering,” the article engages in a multimodal text analysis of four news stories about e-waste. The findings show how on-location reports from e-waste dumping sites make use of sublime imagery in the visual representations; how e-waste dumping sites are presented as strange spaces, with no clear and comprehensible history; and finally, that the representations suggest an ambivalence and uncertainty when it comes to agency (who is responsible and what can be done?). The article ends with a discussion of the implications of this mode of representation and its effectiveness in eliciting an appropriate response to the harms caused by e-waste.  相似文献   
94.
Severe environmental problems documented in the Baltic Sea in the 1960s led to the 1974 creation of the Helsinki Convention for the Protection of the Marine Environment of the Baltic Sea Area. We introduce this special issue by briefly summarizing successes and failures of Baltic environmental management in the following 40 years. The loads of many polluting substances have been greatly reduced, but legacy pollution slows recovery. Top predator populations have recovered, and human exposure to potential toxins has been reduced. The cod stock has partially recovered. Nutrient loads are decreasing, but deep-water anoxia and cyanobacterial blooms remain extensive, and climate change threatens the advances made. Ecosystem-based management is the agreed principle, but in practice the various environmental problems are still handled separately, since we still lack both basic ecological knowledge and appropriate governance structures for managing them together, in a true ecosystem approach.  相似文献   
95.
96.
"21世纪的食物",是一项包括整个农业食物链的跨学科研究计划,于1997~2004年在瑞典实施.该研究所面临的挑战是为整个食物链中存在的不可持续的活动提出环境分析工具和解决方案.这需要科学家和食物链利益相关人紧密合作.本文提出了一整套以可持续食物生产为特征的目标方案.综合和系统分析是用来分析拟定变化的可持续性的主要工具.在本文中我们对"21世纪的食物"的概念进行概述,同时着重说明一些结论.例如,我们发现:就环境影响和产品质量而言,总体上来说,有机农业及其产品并不比常规的产品和方法优越.项目所采用的一些管理经验非常独特,这也是项目成功完成的重要原因,所以本文中我们对此也进行了总结.  相似文献   
97.
Andersson B 《Ambio》2001,30(8):503-513
The four largest Swedish lakes, V?nern, V?ttern, Hj?lmaren, and M?laren, were surveyed by means of aerial IR-color photography in the 1970s. Along small slope gradients in all lakes the emergent communities extended to a width of hundreds of meters, while the extent on steeper slopes was a few meters. Because of the fractionate shape, L. M?laren has a very long shoreline, which promotes vegetation growth in the transition zone between land and water. Sheltered conditions are numerous and water lilies and other floating leaved and freely floating plants are abundant. Emergent as well as submerged macrophytes grow vigorously in the northernmost part of the oligotrophic lake V?ttern. In L. V?nern exposed shores pre-dominate, but sheltered bays and archipelagos are overgrown with reeds. In the shallow lake Hj?lmaren monospecific stands of Phragmites australis are dominant. Recurrent surveys of L. M?laren and L. V?nern in the 1990s showed changes that could be connected to the watertable fluctuations, which have been stabilized since the first investigation. Reeds and water lilies expanded in sheltered parts of the lakes, while the distribution of reed stands growing at their deep limit decreased.  相似文献   
98.
2-Hydroxybiphenyl and 2-(2,4-dichlorophenoxy)-4,5,6-trichlorophenol and their methyl ethers were perchlorinated with four different reagents of various strengths. It was shown that perchlorination is not a reliable method in the analysis of these compounds. Pure octachlorodibenzofuran and nonachlorohydroxybiphenyl were, however, synthesized by the perchlorination procedure.  相似文献   
99.
Optically stimulated luminescence (OSL) has been used for estimation of the accumulated doses in quartz inclusions obtained from two fired bricks, extracted in July 2004 from a building located in the forested surroundings of the recreational area Novie Bobovichi, the Bryansk Region, Russia. The area was significantly contaminated by Chernobyl fallout with initial (137)Cs ground deposition level of approximately 1.1 MBq m(-2). The accumulated OSL doses in sections of the bricks varied from 141 to 207 mGy, of which between 76 and 146 mGy are attributable to Chernobyl fallout. Using the OSL depth-dose profiles obtained from the exposed bricks and the results from a gamma-ray-survey of the area, the Chernobyl-related cumulative gamma-ray dose for a point detector located in free air at a height of 1m above the ground in the study area was estimated to be ca. 240 mGy for the time period starting on 27 April 1986 and ending on 31 July 2004. This result is in good agreement with the result of deterministic modelling of the cumulative gamma-ray dose in free air above undisturbed ground from the Chernobyl source in the Bryansk Region. Over the same time period, the external Chernobyl-related dose via forest pathway for the most exposed individuals (e.g., forest workers) is estimated to be approximately 39 mSv. Prognosis for the external exposure from 1986 to 2056 is presented and compared with the predictions given by other investigators of the region.  相似文献   
100.
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