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   165篇
  免费   0篇
  国内免费   8篇
安全科学   6篇
废物处理   3篇
环保管理   23篇
综合类   35篇
基础理论   33篇
污染及防治   38篇
评价与监测   19篇
社会与环境   9篇
灾害及防治   7篇
  2023年   1篇
  2022年   3篇
  2021年   4篇
  2018年   7篇
  2017年   2篇
  2016年   8篇
  2015年   3篇
  2014年   6篇
  2013年   5篇
  2012年   9篇
  2011年   16篇
  2010年   9篇
  2009年   6篇
  2008年   12篇
  2007年   8篇
  2006年   9篇
  2005年   6篇
  2004年   9篇
  2003年   11篇
  2002年   7篇
  2001年   2篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1992年   2篇
  1991年   2篇
  1989年   1篇
  1987年   2篇
  1986年   1篇
  1983年   1篇
  1982年   2篇
  1979年   2篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
  1960年   1篇
排序方式: 共有173条查询结果,搜索用时 15 毫秒
101.
Environmental Science and Pollution Research - The organochlorine pollution by chlordecone, an insecticide spread in the past in banana plantations, is now recognized as a major ecological,...  相似文献   
102.
Microbial communities in sewage sludge and green waste co-composting were investigated using culture-dependent methods and community level physiological profiles (CLPP) with Biolog Microplate. Different microbial groups characterized each stage of composting. Bacterial densities were high from beginning to end of composting, whereas actinomycete densities increased only after bio-oxidation phase i.e. after 40 days. Fungal populations become particularly high during the last stage of decomposition. Cluster analyses of metabolic profiles revealed a similar separation between two groups of composts at 67 days for bacteria and fungi. Principal component analysis (PCA) applied to bacterial and fungal CLPP data showed a chronological distribution of composts with two phases. The first one (before 67 days), where the composts were characterized by the rapid decomposition of non-humic biodegradable organic matter, was significantly correlated to the decrease of C, C/N, organic matter (OM), fulvic acid (FA), respiration, cellulase, protease, phenoloxidase, alkaline and acid phosphatases activities. The second phase corresponding to the formation of polycondensed humic-like substances was significantly correlated to humic acid (HA) content, pH and HA/FA. The influent substrates selected on both factorial maps showed that microbial communities could adapt their metabolic capacities to the particular environment. The first phase seems to be focused on easily degradable substrate utilization whereas the maturation phase appears as multiple metabolisms, which induce the release of metabolites and their polymerization leading to humification processes.  相似文献   
103.
要使发展具有可持续性,我们必须规划一种经济模式,把所有的工作永远都维持在这颗行星环境的限制之内.商业能够为这个共同的事业所做出的最重要贡献就是革新--不是只为了新奇的革新,或者仅在商业领域的革新.如果我们要夺取胜利,技术、消费者行为、社会关系和政策框架的革新必须联合进行.  相似文献   
104.
105.
We investigated the ontogeny of responses to scent marks in immature terrestrial salamanders (Salamandra lanzai) that inhabit the southwest Alps. In this species, sexual maturity is usually reached at about 8 years, and adults exhibit territoriality. One should expect territoriality to take place largely before the acquisition of sexual maturity if sexual competition is not the main force driving territoriality. However, both the difficulties for inexperienced animals to find a suitable territory and size-related competition may delay the acquisition of territoriality in juveniles. We performed choice tests with juveniles belonging to two age groups (1±1 years old versus 4±1 years old). Each focal animal was offered, in random order, the choice between two shelters, one without scent and the other containing one of the following scents: own, same-aged animal, a juvenile belonging to the other age group, or adult female. We also performed choice tests with adult females for which the scents of two juveniles belonging to a different age group were successively offered in a random order. Older juveniles were strongly attracted toward their own shelter and mostly avoided the shelters that contained the scent of juveniles of about the same age and of adult females. Adult females avoided the scents of older juveniles but not younger juveniles. These results therefore suggest that older juveniles use territorial marking. Conversely, young juveniles behaved randomly with respect to their own scents and to those of a same-aged juvenile, and they were significantly attracted towards the odor of an older animal, especially adult females. Both older juveniles and adult females displayed a random behavior toward the scents of young juveniles. Our results suggest that young juveniles do not defend territories but use spaces occupied by older individuals.Communicated by A. Mathis  相似文献   
106.
Regional Environmental Change - To address sustainability challenges of agro-ecosystems located in Mediterranean urban regions, this paper focuses on the multidisciplinary subject of urban...  相似文献   
107.
108.
109.
The relationship between exposure to the World Trade Center (WTC) attacks, increased substance use, functional impairment and mental health service use, controlling for depression and post-traumatic stress disorder, was assessed through an in-school survey of directly exposed students (N = 1040) attending the five middle and five high schools nearest the WTC. The survey was conducted 18 months after the attacks. Students with one WTC exposure risk factor had a five-fold increase in substance use, while those with three or more exposure risks had a nearly 19-fold increase. Increased substance use was associated with impaired school work, school behaviour and grades. Students reporting increased substance use were nearly twice as likely to want help but were no more likely than asymptomatic students to receive services. Adolescents reporting increased substance use, without co-morbidity, were less likely to receive psychological services than others. Attention to the needs of substance-using adolescents exposed to disaster is needed.  相似文献   
110.
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