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   9598篇
  免费   396篇
  国内免费   440篇
安全科学   657篇
废物处理   120篇
环保管理   1853篇
综合类   3957篇
基础理论   718篇
环境理论   20篇
污染及防治   647篇
评价与监测   2039篇
社会与环境   300篇
灾害及防治   123篇
  2024年   16篇
  2023年   113篇
  2022年   173篇
  2021年   176篇
  2020年   312篇
  2019年   177篇
  2018年   166篇
  2017年   249篇
  2016年   333篇
  2015年   346篇
  2014年   460篇
  2013年   573篇
  2012年   491篇
  2011年   731篇
  2010年   417篇
  2009年   579篇
  2008年   459篇
  2007年   519篇
  2006年   478篇
  2005年   343篇
  2004年   312篇
  2003年   432篇
  2002年   323篇
  2001年   319篇
  2000年   330篇
  1999年   268篇
  1998年   247篇
  1997年   239篇
  1996年   165篇
  1995年   111篇
  1994年   127篇
  1993年   111篇
  1992年   74篇
  1991年   49篇
  1990年   28篇
  1989年   29篇
  1988年   17篇
  1987年   15篇
  1986年   23篇
  1985年   21篇
  1984年   19篇
  1983年   8篇
  1982年   11篇
  1981年   8篇
  1980年   10篇
  1979年   3篇
  1978年   14篇
  1977年   6篇
  1973年   2篇
  1969年   1篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
841.
无线传感器网络在环境监测中的应用   总被引:5,自引:0,他引:5  
介绍了一种基于无线传感器网络的环境监测系统组成及架构,讨论了系统网络节点、网关的硬件设计,并对基于TinyOS的应用程序组件结构和节点工作流程做了说明。  相似文献   
842.
原子荧光光谱法同时测定环境水体中痕量锡和锌   总被引:2,自引:0,他引:2  
采用原子荧光光谱法同时测定环境水样中痕量锡和锌,优化了试验条件。锡在1.00μg/L~10.0μg/L、锌在20.0μg/L~200μg/L范围内线性良好,方法检出限锡为0.13μg/L,锌为1.76μg/L,锡和锌标准溶液测定的相对标准偏差分别为2.9%和4.0%,环境水样加标回收率锡为96.4%~106%,锌为92.0%~111%。  相似文献   
843.
水质生物毒性在线监测技术研究进展   总被引:5,自引:1,他引:4  
从生物分子、细胞、个体、种群和群落水平,系统介绍了国内外研发的水质毒性在线监测技术,归纳分析了各种技术的特点及应用,并提出了其发展前景与趋势。  相似文献   
844.
Rising populations and incomes throughout the world have boosted meat demand by over 75% in the last 20years, intensifying pressures on production systems and the natural resources to which they are linked. As a growing proportion of global meat production is traded, the environmental impacts of production become increasingly separated from where the meat is consumed. In this paper, we quantify the use of three important resources associated with industrial livestock production and trade—water, land, and nitrogen—using a country-specific model that combines trade, agronomic, biogeochemical, and hydrological data. Our model focuses on pigs and chickens, as these animals are raised predominantly in intensive systems using concentrated, compound feeds. The results describe the geographical patterns of environmental resource use due to meat production, trade, and consumption. We show that US feed, animal, and meat destined for export require almost as much nitrogen and land, and 20% more water, than products destined for domestic consumption. Model results also demonstrate that among various production factors, improvements in crop yields and animal feed conversion efficiencies result in the most significant reductions in environmental harm. By explicitly tracking the externalities of meat production, we hope to bolster suppliers’ accountability and provide better information to meat consumers.
Kirsten OlesonEmail:
  相似文献   
845.
In this study, an interval-fuzzy two-stage chance-constrained integer programming (IFTCIP) method is developed for supporting environmental management under uncertainty. The IFTCIP improves upon the existing interval, fuzzy, and two-stage programming approaches by allowing uncertainties expressed as probability distributions, fuzzy sets, and discrete intervals to be directly incorporated within a general mixed integer linear programming framework. It has advantages in uncertainty reflection, policy investigation, risk assessment, and capacity-expansion analysis in comparison to the other optimization methods. Moreover, it can help examine the risk of violating system constraints and the associated consequences. The developed method is applied to the planning for facility expansion and waste-flow allocation within a municipal solid waste management system. Violations of capacity constraints are allowed under a range of significance levels, which reflects tradeoffs between the system cost and the constraint-violation risk. The results indicate that reasonable solutions for both binary and continuous variables have been generated under different risk levels. They are useful for generating desired decision alternatives with minimized system cost and constraint-violation risk under various environmental, economic, and system-reliability conditions. Generally, willingness to take a higher risk of constraint violation will guarantee a lower system cost; a strong desire to acquire a lower risk will run into a higher system cost.  相似文献   
846.
Mixed-integer linear programs are proposed for siting development and conservation areas in watersheds, addressing economic objectives (development perimeter and proximity) and ecological objectives. Links between watershed hydrology and ecology need not be well defined. Parameters for the linear programs are obtained from linearization of the SWAT hydrologic model.  相似文献   
847.
“十二五”新疆环境监测能力建设之展望   总被引:1,自引:1,他引:0  
依据全疆当前环境监测体系能力建设现状,从监测机构发展和监测网络能力发展的角度上较深刻分析了当前全疆环境监测体系存在的主要问题,提出了“十二五”新疆环境监测能力建设的设想和展望,共同行参考。  相似文献   
848.
介绍了在环境监测分析中精确配制一定浓度标准溶液的快速方法。利用双三角解析法称量标准物质和配制标准溶液,实验过程快速、准确。在环境监测分析应用中取得较好效果,不确定度无显著差异。  相似文献   
849.
回顾分析了淮安市饮用水源地污染事件的应急监测和处置方法,总结了应急监测及处置工作的经验教训和启示,对更好地驾驭今后可能发生的各种复杂的环境事件提供了帮助。  相似文献   
850.
The quantitative assessment of health impacts has been identified as a crucial feature for realising the full potential of health impact assessment (HIA). In settings where demographic and health data are notoriously scarce, but there is a broad range of ascertainable ecological, environmental, epidemiological and socioeconomic information, a diverse toolkit of data collection strategies becomes relevant for the mainly small-area impacts of interest. We present a modular, cross-sectional baseline health survey study design, which has been developed for HIA of industrial development projects in the humid tropics. The modular nature of our toolkit allows our methodology to be readily adapted to the prevailing eco-epidemiological characteristics of a given project setting. Central to our design is a broad set of key performance indicators, covering a multiplicity of health outcomes and determinants at different levels and scales. We present experience and key findings from our modular baseline health survey methodology employed in 14 selected sentinel sites within an iron ore mining project in the Republic of Guinea. We argue that our methodology is a generic example of rapid evidence assembly in difficult-to-reach localities, where improvement of the predictive validity of the assessment and establishment of a benchmark for longitudinal monitoring of project impacts and mitigation efforts is needed.  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