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   93篇
  免费   0篇
  国内免费   1篇
安全科学   4篇
废物处理   2篇
环保管理   3篇
综合类   51篇
基础理论   13篇
污染及防治   15篇
评价与监测   2篇
社会与环境   4篇
  2023年   1篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   3篇
  2017年   2篇
  2016年   5篇
  2015年   12篇
  2014年   4篇
  2013年   10篇
  2012年   4篇
  2011年   2篇
  2010年   2篇
  2009年   2篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   1篇
  2004年   5篇
  2003年   2篇
  2002年   3篇
  2001年   1篇
  1999年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1989年   2篇
  1985年   1篇
  1977年   1篇
  1975年   1篇
  1966年   1篇
  1961年   2篇
  1954年   1篇
  1953年   1篇
  1952年   1篇
排序方式: 共有94条查询结果,搜索用时 15 毫秒
61.
62.
The public perception of climate change is characterized by heterogeneity, even polarization. Deliberative discussion is regarded by some as key to overcoming polarization and engaging various publics with the complex issue of climate change. In this context, online engagement with news stories is seen as a space for a new “deliberative democratic potential” to emerge. This article examines aspects of deliberation in user comment threads in response to articles on climate change taken from the Guardian. “Deliberation” is understood through the concepts “reciprocity”, “topicality”, and “argumentation”. We demonstrate how corpus analysis can be used to examine the ways in which online debates around climate change may create or deny opportunities for multiple voices and deliberation. Results show that whilst some aspects of online discourse discourage alternative viewpoints and demonstrate “incivility”, user comments also show potential for engaging in dialog, and for high levels of interaction.  相似文献   
63.
64.
65.
66.
In vitro effects of Pb2+, the pyrethroid insecticides cypermethrin, fenvalerate and the syner‐gist piperonyl butoxide on sodium‐potassium‐activated adenosine triphosphatase (Na,K‐ATPase) from dog kidney were determined. Pb2+ with an estimated IC50 value of 5.2 μM was found to be a potent inhibitor of Na,K‐ATPase activity, whereas Na,K‐ATPase was less sensitive to the pyrethroids tested and piperonyl butoxide. Investigation with circular dichroism (CD) spec‐troscopy showed that inhibition occurs through conformational changes of the α‐subunit of the enzyme. The kinetic characteristics of inhibition of Na,K‐ATPase with varying substrate (ATP) concentrations as well as with varying Na+ concentrations exhibited a competitive type of inhibition with Pb2+ in the μM range. With Pb2+ alone in the enzyme assay no conformational changes of the protein could be observed which confirmed the assumption that Pb2+ can bind to the Na+ binding site of the α‐subunit. Uncompetitive type of inhibition occurred with varied K+ concentrations demonstrating that this cation binding site is not affected directly by Pb2+.

Complete reversal of Pb2+ by DTT confirms that a possible target for interaction of this heavy metal ion with Na, K‐ATPase are specific SH groups.

Synergistic effects could only be determined with higher Pb2+ concentrations of 3, 5 and 7 μM plus piperonyl butoxide while all other combinations with this heavy metal plus organic substances where of the additive type. With CD spectroscopy also only additive effects were observed. These results demonstrate that higher concentrations of piperonyl butoxide favor the binding of Pb2+ to the Na+ binding site by conformational changes of the protein.  相似文献   
67.
Paysandisia archon was accidentally introduced into Europe where it damages endemic and ornamental palms, also threatening the date palm from North Africa. Little was known about sex pheromones in the Castniidae day-flying moth before a recent paper that concluded on the absence of female sex pheromone in P. archon. A putative identification of a short-range male pheromone, present on fore- and hindwings, was reported. In this paper, we describe the original structure of the male androconia located on the tarsi of the mid-legs. The extracts of mid-legs were analysed by GC/MS and the chemical structure of the male androconia component was identified as E2,Z13-18:OH. After extraction in solvent, biological activity of the extracts was assessed by EAG. The chemistry and the morphology of the androconia reinforce the current classification of the Castniidae in the Cossoid/Sesioid assemblage and provide new information on the chemical ecology in day-flying Lepidoptera and suit the recent paper describing the courtship behaviour  相似文献   
68.
In order to ensure equality of occupational health care among employees of small and medium-sized enterprises (SMEs) and of larger companies, amendments in the regulations of the numerous German accident insurance funds had to be made to provide for full availability of services, as requested by German and European law. According to these amendments, sectors formerly exempted due to small size and due to lack of an adequate number of qualified personnel, had to be covered by occupational health care. In order to reach this target group new strategies of care delivery had to be developed, making use of pre-existing infrastructure and networks.

In Germany, district trade association (Kreishandwerkerschaften) have proved to be very effective for introducing occupational safety and health care into SMEs by either hiring external multidisciplinary services or by establishing a common service to be used by all associated crafts establishments. In a study conducted by the Federal Office for Health and Safety at Work in 1996 (Boldt, Gille, &Grahl, 1997), 7 district trade association were looked at in detail for their strategies. The results were discussed and supplemented in a 2-day workshop.  相似文献   
69.
The degree of association between industrial odours and reported annoyance was investigated by means of field studies in four German cities, namely Duisburg (n = 400), Brühl (n = 539), Dortmund (n = 400) and Rodenkirchen (n = 200). The degree of odour exposure was assessed by estimating the frequency of odours by means of systematic field observations, whereas annoyance was assessed by personal interviews using standardized questionnaires. Both studies revealed highly significant associations between odour exposure and degree of annoyance. Odour annoyance was correlated with personal factors: age was negatively related to annoyance, whereas dissatisfaction with health exhibited positive associations with annoyance. Coping strategies were also associated with odour annoyance: high scores in problem-oriented coping strategies increased annoyance, whereas high scores in avoidance coping reduced annoyance. Coping strategies based upon the reduction of emotional stress were not associated with annoyance. Since none of the interaction terms of the full regression model proved significant, no true moderators were identified. In order to check for aquiescence bias, people who were interviewed personally were compared with those who could not be approached directly and who were therefore contacted by mail. Despite some significant differences in terms of gender, education, occupation, problem-oriented coping and avoidance coping, both groups did not differ in terms of annoyance.  相似文献   
70.
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