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   87篇
  免费   0篇
  国内免费   1篇
安全科学   2篇
废物处理   2篇
环保管理   6篇
综合类   27篇
基础理论   35篇
污染及防治   14篇
社会与环境   2篇
  2022年   1篇
  2018年   3篇
  2015年   2篇
  2014年   4篇
  2013年   1篇
  2012年   1篇
  2011年   2篇
  2009年   3篇
  2008年   2篇
  2007年   1篇
  2006年   8篇
  2005年   4篇
  2004年   5篇
  2003年   5篇
  2002年   1篇
  2001年   6篇
  2000年   2篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1978年   2篇
  1977年   1篇
  1974年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
  1965年   2篇
  1963年   2篇
  1962年   2篇
排序方式: 共有88条查询结果,搜索用时 93 毫秒
81.
82.
2-Ethylhexanol has been identified as a volatile organic compound (VOC) that contributes to the deterioration of indoor air quality. Plasticizers are common components of dust and building materials and are shown to be degraded by a variety of bacteria and fungi to produce 2-ethylhexanol and other metabolites. Of these, the 2-ethylhexanol has significant volatility and was observed in appreciable quantities. The degree to which 2-ethylhexanol is observed as a VOC in air samples would be limited by the fact that many of the microorganisms that are capable of producing this compound are also able to oxidize it to 2-ethylhexanoic acid, which is much less volatile. It is argued that an abiotic degradation mechanism of plasticizers that results in the generation of 2-ethylhexanol is unlikely and, if this did occur, other metabolites should have been observed. Thus, the microbial degradation of plasticizers is the most likely source of 2-ethylhexanol in indoor air.  相似文献   
83.
The present report describes two fetuses, one female and one male, with thus far undescribed skeletal malformations. The mother was a gravida 2, para 0. Both pregnancies were terminated in the second trimester because of multiple congenital anomalies diagnosed ultrasonographically resembling a short rib-polydactyly syndrome. Both fetuses were found to have postaxial hexadactyly of the hands and feet, marked bilateral campomelia of the forearm and shank bones, and a Dandy–Walker cyst. In addition, the fourth ventricle was dilated in the first sibling and the second sibling had an inverse intestinal malrotation. A literature search failed to reveal similar observations. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
84.
Coffin-Lowry syndrome is a rare X-linked, semi-dominant mental retardation syndrome resulting from mutations of the ribosomal S6 kinase 2 (RSK2) gene. In the present report, a male patient affected with Coffin-Lowry syndrome is shown to have a nonsense mutation of the RSK2 gene. His unaffected mother does not have this mutation in her lymphocytes. In her third pregnancy prenatal diagnosis by mutation analysis has detected gonadal mosaicism. As this is the second report of germinal mosaicism in Coffin-Lowry syndrome, the finding has important implication for genetic counselling. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
85.
86.
The phytohormone GA(3) in needles from 4-year-old Norway spruce trees was analyzed after treatment with ozone and acid mist in environmental chambers under controlled conditions. GA(3) was extracted with methanol from the lyophilized material. Subsequent purification steps included the use of polyvinylpyrollidone (PVP), cartridge reversed-phase purification, ethylacetate extraction and HPLC. The GA(3) was determined in the methylated form by means of a highly specific and sensitive enzyme immunoassay. Higher GA(3) contents were detected in young needles (year 1987) as compared to older ones (year 1986). However, no statistically significant differences were found in the GA(3) levels between the controls and the needles of trees which were treated with increased levels of ozone and acidic mist.  相似文献   
87.
88.
Today, a variety of different approaches to the recovery of phosphorus from wastewater, sludge, and sludge ash exist. These approaches differ basically by the origin of the used matter (wastewater, sludge liquor, fermented or nonfermented sludge ash) and the process (precipitation, wet-chemical extraction, and thermal treatment). To rate them according to their characteristics, the latter were phrased as hypotheses and subjected to an international expert survey. The survey showed that phosphorus recovery is expected to become an established process over the next 20 years in industrialized countries for economic reasons. A decisive aspect in this regard will be the quality of the produced fertilizer. Simple technologies such as the recovery from sludge liquor seem to be preferred. If sludge is incinerated, phosphorus recycling from ash then becomes more interesting and has to be considered. Phosphorus recovery and source-separating sanitation technologies are more appropriate for industrialized countries than for developing countries. Because the growing awareness of environmental issues will prevent sludge from being used agriculturally in an increasing number of countries in the next decade, the market potential for nutrient recovery technologies will increase in the immediate future.  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