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   69篇
  免费   5篇
  国内免费   9篇
环保管理   1篇
综合类   12篇
基础理论   65篇
污染及防治   4篇
社会与环境   1篇
  2020年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   1篇
  2012年   3篇
  2011年   4篇
  2010年   3篇
  2009年   5篇
  2008年   9篇
  2007年   9篇
  2006年   9篇
  2005年   7篇
  2004年   7篇
  2003年   4篇
  2002年   1篇
  2000年   1篇
  1999年   3篇
  1996年   1篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
排序方式: 共有83条查询结果,搜索用时 5 毫秒
81.
The aim of this study was to assess the potential for coexistence between rural people (living adjacent to a protected area) and predators (from the same area) ranging onto communal land. Ninety members of local communities bordering Manyeleti Game Reserve, which is contiguous with Kruger National Park, South Africa were interviewed. Respondents expressed diverging attitudes toward predators, which were more favorable among participants with higher education. Negative views were particularly due to fear of human and livestock losses, especially to lions, Panthera leo. Lions were thought to be the most abundant predator both within and outside the reserve. Lions were also the best known predator and were most often held responsible for killing livestock. Despite these livestock losses and a lack of conservation education, most participants voiced favorable opinions about large carnivore conservation, as predators were considered an integral part of the respondents’ natural heritage. Thanks to this cultural tolerance and also because of a largely accepted management policy regarding predator control, large carnivores and people can coexist in the vicinity of Kruger National Park.  相似文献   
82.
利用寡毛纲蠕虫-水丝蚓(Limnodrilus sp.)的捕食实现污泥量的削减,并针对曝气强度对蠕虫捕食污泥过程的影响,考察了不同的曝气强度所引起的蠕虫活性、泥水性质和污泥减量效能等的变化.结果表明:蠕虫对曝气强度的耐受能力有限,其受损程度与曝气强度和时间正相关,低强度的间歇曝气下蠕虫受损数量较低,为总数的1.7%.蠕虫的组织乳酸脱氢酶活力在2.8~9.5m3/(m2·h)的曝气强度下明显升高,表现了较高的物质代谢和能量消耗水平.较低的曝气强度下污泥上清液中硝酸盐氮的累积较轻.蠕虫对污泥的捕食能够抑制低曝气强度下溶氧缺乏所引起的污泥容积指数(SVI)增加,改善污泥的沉降性.在2.8m3/(m2·h)的间歇曝气下,污泥减量效率比连续曝气的污泥减量效率更稳定.  相似文献   
83.
Summary. Geckos consumed immature Bactrocera carambolae males readily, but their consumption was reduced significantly when offered sexually mature males. They showed a similar aversion for sexually mature males previously fed with methyl eugenol. When male flies at different ages were offered to starved geckos, geckos’ consumption showed an age-related anti-feeding effect, which was concomitant with the production trend of 6-oxo-1-nonanol, a major endogenous component synthesized in the male rectal gland. The production of 6-oxo-1-nonanol was also age-related and corresponded with sexual maturity as reported previously. Topical application of the authentic chemical of 6-oxo-1-nonanol onto the thorax of female fruit flies, at the amount normally detected in the rectal gland of a sexually mature male, had the same deterrent effect against geckos.  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