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   445篇
  免费   1篇
  国内免费   2篇
安全科学   69篇
废物处理   15篇
环保管理   9篇
综合类   50篇
基础理论   49篇
污染及防治   175篇
评价与监测   50篇
社会与环境   30篇
灾害及防治   1篇
  2023年   5篇
  2022年   4篇
  2021年   9篇
  2020年   6篇
  2019年   19篇
  2018年   22篇
  2017年   25篇
  2016年   31篇
  2015年   8篇
  2014年   23篇
  2013年   64篇
  2012年   29篇
  2011年   22篇
  2010年   12篇
  2009年   6篇
  2008年   18篇
  2007年   18篇
  2006年   11篇
  2005年   13篇
  2004年   21篇
  2003年   17篇
  2002年   9篇
  2001年   5篇
  2000年   7篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1993年   1篇
  1992年   2篇
  1991年   2篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1984年   2篇
  1982年   1篇
  1979年   2篇
  1968年   1篇
  1967年   1篇
  1965年   3篇
  1964年   1篇
  1963年   3篇
  1962年   4篇
  1961年   2篇
  1960年   3篇
  1959年   1篇
  1958年   1篇
  1931年   1篇
排序方式: 共有448条查询结果,搜索用时 31 毫秒
441.
In this paper, we review the phenomenon of nectar resorption, focusing on its physiological and ecological meaning. Nectar resorption is a phenomenon that has long been known but was rarely reported until the1990s. It has more recently been demonstrated in several species by various direct and indirect methodologies. It has generally been demonstrated in senescent flowers as a phenomenon separate in time from, and independent of, nectar secretion. The significance of this type of resorption is generally recognized as a resource-recovery strategy, recycling at least some materials invested in nectar production. Nevertheless, nectar resorption can occur concomitantly with nectar secretion. Nectar production is therefore best considered as a unified process comprising nectar secretion and resorption. The modulation of these two opposite phases allows nectar concentration to be maintained in a range suitable for pollinators (nectar homeostasis). The mechanism of nectar resorption at the cell level has received little attention, and its molecular basis can only be hypothesized on the basis of recent studies concerning sugar sensing.  相似文献   
442.
The objective of the study was to investigate the presence and the activity of quantum dots nanoparticles in colored wastewaters. The special interest is devoted to the investigation of their role in the typical treatment of water or wastewater, studying their influence on the effectiveness of applied treatments methods. The standard chemical processes for water treatment and disinfection (direct UV photolysis and direct ozonation) were applied for the degradation of colored organic pollutant, reactive azo dye, in the presence/absence of CdSe/ZnS core-shells quantum dots. The obtained results indicated that investigated nanoparticles inhibit the overall efficiency of applied processes, especially in the case of direct UV photolysis, although catalytic effect might be expected in part due to the semiconductor nature of quantum dots. Such results lead to a conclusion that CdSe/ZnS nanoparticles behave as additional pollutants in the system. They should be removed from the system prior the treatment, because their presence could decrease the efficiency, i.e., prolong the time of treatment and correspondingly increase the costs of the treatment process.  相似文献   
443.
Journal of Polymers and the Environment - In the study, polylactide-based (PLA) composites modified with natural particles (wood, bamboo, and cork) and with different levels of infilling (100%,...  相似文献   
444.
Environmental Geochemistry and Health - The authors present the results of chemical and mineralogical analyses of urban dusts collected in the spring seasons of 2015 and 2016 in three different...  相似文献   
445.
Environmental Geochemistry and Health - Leachate from landfills is a product of complex biological and physicochemical processes occurring during waste storage. In the present study, the toxicity...  相似文献   
446.
Environmental Science and Pollution Research - The studies presented in this work show that solid tannery waste-like shavings can be used as high-protein materials for fertilizer production...  相似文献   
447.
Environmental Science and Pollution Research - Escherichia coli bacteria are an essential indicator in evaluations of environmental pollution, which is why they must be correctly identified. This...  相似文献   
448.
Environmental Science and Pollution Research - In this study, we report the potential of 2D/2D TiO2-GO-ZnFe2O4 photocatalyst obtained using the fluorine-free lyophilization technique for the...  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