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   660篇
  免费   27篇
  国内免费   257篇
安全科学   45篇
废物处理   51篇
环保管理   47篇
综合类   344篇
基础理论   142篇
污染及防治   232篇
评价与监测   28篇
社会与环境   26篇
灾害及防治   29篇
  2023年   11篇
  2022年   35篇
  2021年   27篇
  2020年   22篇
  2019年   20篇
  2018年   24篇
  2017年   26篇
  2016年   27篇
  2015年   46篇
  2014年   58篇
  2013年   70篇
  2012年   52篇
  2011年   66篇
  2010年   44篇
  2009年   32篇
  2008年   38篇
  2007年   52篇
  2006年   35篇
  2005年   25篇
  2004年   17篇
  2003年   23篇
  2002年   19篇
  2001年   17篇
  2000年   21篇
  1999年   27篇
  1998年   17篇
  1997年   16篇
  1996年   15篇
  1995年   9篇
  1994年   10篇
  1993年   9篇
  1992年   10篇
  1991年   7篇
  1990年   7篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1982年   2篇
  1981年   1篇
排序方式: 共有944条查询结果,搜索用时 578 毫秒
561.
A new process of flue gas desulfurization in circulating fluidized bed with flue gas bypass ducts is presented. k? Model, Discrete Phase Model and Finite-Rate Chemistry Model are proposed to simulate the desulfurization process characteristics in circulating fluidized bed reactor. The proposed model is validated by the comparison of experimental data and simulation results. The results show that the desulfurization reactor with bypass ducts is superior to the reactor without bypass ducts. The reactor with bypass ducts has higher desulfurization efficiencies and lower flow resistances than the reactor without bypass ducts, and it is more suitable for flue gas flow variation. Desulfurization reaction rate is controlled by absorption reaction on sorbent particles surface. When water content and Ca/S ratio increase, desulfurization efficiency of the reactor with bypass ducts increases. When SO2 concentration increases, desulfurization efficiency decreases.  相似文献   
562.
The production and application of organophosphate esters (OPEs) have dramatically increased in recent years due to their use as a replacement for brominated flame retardants. In this study, 13 OPEs (Σ13OPEs) were analyzed in indoor air samples from kitchens and living rooms in 14 residential homes in Beijing, China. The concentrations of Σ13OPEs in kitchen air samples (mean: 13 ng/m3) were significantly (p < 0.05) higher than in living room air samples (5.0 ng/m3). In addition, paired window surface organic film samples were collected and analyzed to investigate film-air partitioning, exhibiting a mean concentration of Σ13OPEs of 4100 ng/m2. The congener profiles showed that tris(2-chloroisopropyl) phosphate (TCPP) was the predominant compound in both window film samples (48%) and the corresponding indoor air sample (56%). The estimated daily intakes (EDI) of OPEs via indoor air inhalation were 2.8 and 1.4 ng/kg/day for infants and adults, respectively, both of which are below the reference dose values (RfDs). Overall, these findings indicate that OPEs in the indoor air environment of residential homes in Beijing are not likely to pose a health risk to the general population.  相似文献   
563.
随着我国城市化建设规模和数量不断增加和扩大,工业固体废物产生量正逐年增加,如何解决工业固体废物是现阶段城市发展中极其重要的问题。工业固体废物需要占据大量的土地资源,长时间的存放会对该区域造成严重的污染。本文主要对工业固体废物综合利用情况进行深入分析,阐述工作思路和目标,并提出针对性的解决措施,从而提高工业固体废物综合利用率,促进城市经济的可持续发展。  相似文献   
564.
565.
Evaluation system can encourage and guide entrepreneurs, and impel them to perform well in environment management. An evaluation method based on advantage structure is established. It is used to analyze entrepreneur environment management behavior in China. Entrepreneur environment management behavior evaluation index system is constructed based on empirical research. Evaluation method of entrepreneurs is put forward, from the point of objective programming-theory to alert entrepreneurs concerned to think much of it, which means to take minimized objective function as comprehensive evaluation result and identify disadvantage structure pattern. Application research shows that overall behavior of Chinese entrepreneurs environmental management are good, specially, environment strategic behavior are best, environmental management behavior are second, cultural behavior ranks last. Application results show the efficiency and feasibility of this method.  相似文献   
566.
通辽市环境保护监测站从2011年开始降水12项监测。本文根据2011年全年降水监测数据分析通辽市空气环境质量状况及存在的问题,探讨空气环境质量与土壤和水质环境质量的综合效应。  相似文献   
567.
自然灾害造成的损失与应急管理的有效性和及时性成反比,而应急管理的有效性和及时性与当前国家的自然灾害领域研究水平以及国家的灾害应急管理体制分不开。对此,本文在简要归纳自然灾害的概念、特点与危害的基础上,阐述了自然灾害应急管理的重要意义。然后,从宏观及微观两个层面对自然灾害应急管理研究成果予以评述,并指出现有研究中存在的不足,进而从社会系统、生态系统和经济系统三个方面展望了自然灾害应急管理未来研究的重点和方向,这对于完善我国自然灾害应急管理研究体系,提升我国自然灾害应急管理水平具有重要的意义。  相似文献   
568.
对华北、西北和南方等地的30余所变电站产生的生活污水的处理及排放情况进行了调研,汇总分析了我国目前变电站主要的污水处理方法、排放方式及其存在的主要问题,并针对各地区的特点提出了相应的解决方案。  相似文献   
569.
杨萍  刘伟东  侯威 《灾害学》2011,26(1):60-64
利用北京地区20个气象观测站1978-2007年逐日平均温度资料,分析了近30年北京地区极端温度事件的变化趋势以及年代际空间演变特征。研究结果显示,北京观象台近30年的两次迁站对研究极端温度事件并无太大影响;近10年夏季显著的热岛效应,是城区极端高温事件发生频次明显高于其他地区的重要原因;尽管北京地区冬季平均温度的空间分布形态变化甚微,并始终存在着明显的热岛效应,但城区极端低温事件的发生频次有可能发生了与热岛效应无关的突变过程。  相似文献   
570.
The dismantling of printed circuit board assemblies (PCBAs) and the recovery of their useful materials can lead to serious environmental impacts mainly due to their complicated physical structure and the variety of toxic elements contained in their material composition. So far, less attention has been paid to their responsible recycling compared to that of bare printed circuit boards. Combined with other materials recovery process, proper dismantling of PCBAs is beneficial to conserve scarce resources, reuse the components, and eliminate or safely dispose of hazardous materials. In analyzing the generation, resources potential and hazardous risk of scrap PCBAs, technologies used for the dismantling of waste PCBAs have been widely investigated and reviewed from the aspects of both industrial application and laboratory-scale studies. In addition, the feasibility of PCBA dismantling has been discussed, the determinants of which, including the heating conditions and mechanical properties have been identified. Moreover, this paper evaluates the environmental consequences caused by the dismantling of PCBAs.  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