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   226篇
  免费   1篇
  国内免费   1篇
安全科学   8篇
废物处理   9篇
环保管理   31篇
综合类   109篇
基础理论   30篇
污染及防治   33篇
评价与监测   3篇
社会与环境   4篇
灾害及防治   1篇
  2019年   4篇
  2017年   2篇
  2016年   4篇
  2015年   2篇
  2014年   3篇
  2013年   15篇
  2012年   8篇
  2011年   3篇
  2010年   5篇
  2009年   6篇
  2008年   8篇
  2007年   11篇
  2006年   5篇
  2005年   6篇
  2003年   2篇
  2002年   10篇
  2001年   2篇
  2000年   8篇
  1999年   4篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1987年   4篇
  1986年   2篇
  1985年   2篇
  1970年   2篇
  1969年   2篇
  1966年   2篇
  1964年   2篇
  1960年   2篇
  1959年   8篇
  1958年   7篇
  1957年   3篇
  1956年   5篇
  1955年   3篇
  1954年   4篇
  1950年   2篇
  1938年   3篇
  1935年   2篇
  1934年   4篇
  1933年   3篇
  1932年   5篇
  1931年   2篇
  1922年   1篇
  1920年   1篇
  1919年   1篇
  1917年   2篇
  1916年   3篇
  1915年   1篇
  1914年   1篇
排序方式: 共有228条查询结果,搜索用时 343 毫秒
181.
We investigate farmers’ intentions to apply biodiversity conservation practices from a psychological perspective, using an adapted version of the theory of planned behaviour (TPB), including group norms and putting emphasis on moral norms and self-identity. The study is based on a quantitative survey (n = 99) in Belgium, analysed using confirmatory factor analyses and path analysis. Results suggest that the impact of attitudes, social norms and perceived behavioural control on intentions is almost fully mediated through moral norms and self-identity. To have a sustained impact, change actions should strive to embed biodiversity conservation into the social norms and into the good farmer identity of the farming community. While acknowledging the explanatory nature of this study, the findings could suggest another view on how to induce behavioural change.  相似文献   
182.
Patterns of Area Sensitivity in Grassland-Nesting Birds   总被引:3,自引:0,他引:3  
Abstract: Between 1995 and 1997, we studied breeding birds in fragments of native tallgrass prairie in southwestern Missouri to determine the effect of habitat fragmentation on grassland bird populations. Data on density and nesting success collected in 13 prairie fragments of various sizes revealed three levels of area sensitivity. The most area-sensitive species, Greater Prairie-Chicken ( Tympanuchus cupido ), was absent from small prairie fragments. An intermediate form of area sensitivity was apparent in only one species, Henslow's Sparrow ( Ammodramus henslowii ), which occurred in lower densities in small than in large prairie fragments. Based on census (i.e., distributional) data, only those two species were area-sensitive (i.e., negatively affected by habitat fragmentation) in southwestern Missouri. A species can be sensitive not only on a distributional level, however, but also by having lower nesting success in small than in large prairie fragments. The Dickcissel ( Spiza americana ) was the only species that was area-sensitive on such a demographic level. These data indicate that we cannot rely solely on census data to describe the sensitivity of grassland-nesting species to habitat fragmentation, but that we also need to investigate demographic data (e.g., nesting success). Whereas it has previously been shown that density measures of forest-nesting birds do not reliably reflect nesting success in habitat fragments of various sizes, ours is the first study that describes this pattern for grassland-nesting species.  相似文献   
183.
There has been much recent interest in the concept of rewilding as a tool for nature conservation, but also confusion over the idea, which has limited its utility. We developed a unifying definition and 10 guiding principles for rewilding through a survey of 59 rewilding experts, a summary of key organizations’ rewilding visions, and workshops involving over 100 participants from around the world. The guiding principles convey that rewilding exits on a continuum of scale, connectivity, and level of human influence and aims to restore ecosystem structure and functions to achieve a self-sustaining autonomous nature. These principles clarify the concept of rewilding and improve its effectiveness as a tool to achieve global conservation targets, including those of the UN Decade on Ecosystem Restoration and post-2020 Global Biodiversity Framework. Finally, we suggest differences in rewilding perspectives lie largely in the extent to which it is seen as achievable and in specific interventions. An understanding of the context of rewilding projects is the key to success, and careful site-specific interpretations will help achieve the aims of rewilding.  相似文献   
184.
185.
186.
A short survey of application areas and selection criteria for the different remote-sensing methods is presented. Microwave sensing is still regarded as one of the more progressive methods and its problem of angular resolution and the principle of synthetic-aperture radar are discussed. Experimental results of microwave probing are presented with examples from agriculture, meteorology, and hydrology.  相似文献   
187.
188.
189.
190.
The sensitivity of the early life stage (ELS) toxicity test for two compounds with different modes of action was determined, and related to other toxicity tests with the same compounds. The zebrafish. Danio rerio, was used as a test organism, and the two model compounds were 1,2,3-trichlorobenzene (123TCB), a non-polar narcotic, and parathion, an acetylcholinesterase (AChE) inhibitor. Hatching and survival after 28 days were significantly reduced in the highest 123TCB treatment (263 microg/l), but not in any of the parathion treatments. Growth of the larvae was negatively affected at parathion concentrations above 20 microg/l, while AChE was only significantly inhibited at the highest concentration, 93 microg/l. No effects on growth were found in the 123TCB treatments. In comparison with acute and chronic studies with both compounds, the ELS test turned out to be less sensitive than chronic studies and more sensitive than acute studies. The difference in sensitivity between the tests systems seems however, to depend on the mode of action of the compound.  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