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   29篇
  免费   2篇
环保管理   1篇
综合类   15篇
基础理论   9篇
环境理论   1篇
污染及防治   2篇
评价与监测   1篇
社会与环境   2篇
  2021年   1篇
  2018年   1篇
  2016年   1篇
  2015年   2篇
  2013年   1篇
  2012年   1篇
  2011年   3篇
  2007年   1篇
  2006年   2篇
  2005年   1篇
  2003年   1篇
  2002年   1篇
  1966年   1篇
  1957年   1篇
  1935年   2篇
  1932年   3篇
  1931年   2篇
  1930年   1篇
  1929年   2篇
  1927年   1篇
  1926年   1篇
  1924年   1篇
排序方式: 共有31条查询结果,搜索用时 612 毫秒
1.
2.
In this paper, we explore a range of concerns that arise in measuring short-term effects of ozone on health. In particular, we tackle the problem of measuring exposure using alternative daily measures of ozone derived from hourly concentrations. We adopt the exposure paradigm of Chiogna and Bellini (Environmetrics 13:55–69, 2002) extending it to ozone concentrations, and we compare its performances with respect to traditional exposure measures by exploiting model selection. To investigate the stability of model selection, we then apply the idea of bootstrapping the modelling process.  相似文献   
3.
Reductions in global bee populations are threatening the pollination benefits to both the planet and people. Whilst the contribution of bee pollination in promoting sustainable development goals through food security and biodiversity is widely acknowledged, a range of other benefits provided by bees has yet to be fully recognised. We explore the contributions of bees towards achieving the United Nation’s Sustainable Development Goals (SDGs). Our insights suggest that bees potentially contribute towards 15 of the 17 SDGs and a minimum of 30 SDG targets. We identify common themes in which bees play an essential role, and suggest that improved understanding of bee contributions to sustainable development is crucial for ensuring viable bee systems.  相似文献   
4.
5.
6.
7.
Cladophora rupestris is a perennial filamentous macroalga belonging to the Chlorophyta. It is widely distributed on both sides of the northern Atlantic Ocean and penetrates into the brackish Baltic Sea down to ca. 4 psu salinity. In this paper we present evidence for genetic differentiation of a Baltic form of this marine alga. We assessed genetic structure within and among 11 populations ranging along a salinity gradient from the Norwegian coast to the northern Baltic Sea proper. Samples of 328 individuals were studied using starch-gel protein electrophoresis to evaluate genetic variability and interpopulation differentiation based on allozymes. Of 11 loci examined, only one was polymorphic. For this locus, encoding superoxide dismutase (SOD-3), a total of seven alleles were distinguished. We found two genetically differentiated groups of populations of C. rupestris, one Baltic Sea group and one North Sea group, with a distinct border in the southern Kattegat near the entrance to the Baltic Sea. The genetic differentiation for SOD-3, expressed as pairwise FST values between the populations, was generally higher within the Baltic Sea group (0.10-0.43) than within the North Sea group (0.05-0.10); in the latter group also fewer pairs of populations differed significantly. Pairs of populations from different groups had the highest FST values (0.20-0.60). Hierarchical analysis of variance showed that 29.6% of the total variation in the SOD-3 locus was explained by variation between the two groups, while only 4.2% was explained by variation among the populations within the groups. The remaining variation (66.2%) was found within the populations.  相似文献   
8.
The widespread contamination by lead and the acidification of the environment ask for a better understanding of the effects of the interaction between lead and calcium on various aspects of health, including disease defense, in wildlife. Here, we investigated the effects of chronic exposure to sublethal levels of lead, combined with high or low dietary calcium, on health and several components of immunity in male and female zebra finches (Taeniopygia guttata). Thirty individuals of each sex were randomly assigned to three groups: a control group, a group exposed to lead with an additional calcium source (i.e. grit) and a group exposed to lead without access to an extra calcium source. Lead was administered as lead acetate via the drinking water (20 ppm) for 38 consecutive days. Exposure to lead increased significantly the concentrations of lead in kidney and bone in individuals of the experimental groups. Furthermore, the lack of a calcium supplement significantly enhanced the uptake of lead. Lead did not affect health indices such as hematocrit, spleen mass and body mass, nor the adrenal stress response. Cell-mediated immune responsiveness, assessed by a delayed-type hypersensitivity response to phytohaemagglutinin, was also not affected by lead exposure. On the other hand, lead exposure did significantly suppress the secondary humoral immune response towards sheep red blood cells in females, but only when the additional calcium source was not available. This effect was not found in males, suggesting sexual differences in susceptibility of humoral immunity to lead treatment in zebra finches.  相似文献   
9.
Quaternary Ammonium Compounds (QACs) are widely found in disinfectants used in hospitals. Benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) predominate in the disinfecting formulations. These compounds are strong irritants and can play a role in the induction of Occupational Asthma among the professionals of health and cleaning. In order to evaluate the potential health effect of these quaternary ammonium compounds to hospital employers, the development of an analytical method for their quantification in indoor air was developed. DDAC aerosols are trapped by adsorption on XAD-2 resin SKC tube. The air in hospital buildings was sampled using a constant debit Gillian pump at a flow of 1.0 l/min (+/-5%). Ion Chromatography (IC) was chosen for the analysis of DDAC especially for its high sensitivity and specificity. The Limit of Detection (LOD) by IC for DDAC is 0.56 mug/ml. Therefore the LOD of atmospheric DDAC is 28 microg/m(3) with an air volume of 100 l and a desorption volume of 5 ml. All DDAC air samples were lower than the LOD of the analytical method by IC. Under the standard conditions of use of the disinfecting solutions (Surfanios, Ampholysine Plus and Amphospray 41), the insignificant volatility of DDAC would not seem to be able to contaminate the indoor hospital atmosphere during the disinfection process. However, the DDAC can contaminate working atmospheres if it is put in suspension by aerosolisation.  相似文献   
10.
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