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   953篇
  免费   40篇
  国内免费   352篇
安全科学   51篇
废物处理   69篇
环保管理   97篇
综合类   487篇
基础理论   140篇
污染及防治   366篇
评价与监测   48篇
社会与环境   50篇
灾害及防治   37篇
  2023年   18篇
  2022年   45篇
  2021年   36篇
  2020年   30篇
  2019年   33篇
  2018年   46篇
  2017年   45篇
  2016年   56篇
  2015年   51篇
  2014年   59篇
  2013年   94篇
  2012年   67篇
  2011年   86篇
  2010年   68篇
  2009年   57篇
  2008年   56篇
  2007年   63篇
  2006年   47篇
  2005年   45篇
  2004年   29篇
  2003年   32篇
  2002年   31篇
  2001年   21篇
  2000年   38篇
  1999年   24篇
  1998年   27篇
  1997年   26篇
  1996年   25篇
  1995年   13篇
  1994年   15篇
  1993年   6篇
  1992年   12篇
  1991年   11篇
  1990年   15篇
  1989年   4篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
排序方式: 共有1345条查询结果,搜索用时 14 毫秒
601.
To create Safe Community is considered a new methodology to promote Harmonious Society in China. Safe Community (SC) is centralized by “injury prevention” which is a concept involved from occupational safety and health in process industry. In this paper, it first examined the definition and elements of SC. Then, it introduced a Safe Community program in Honey Lake of Futian District of Shenzhen in detail to depict the actual procedure to create a desired Safe Community in China. In this application, Occupational Safety and Health Council in Hong Kong played an important role to instruct the design and execution of SC principle and suggest ways to crystallize a culture of safety within a Chinese community. From the SC program in Honey Lake of Futian District of Shenzhen, China has found out a new way to promote injury prevention in a community. Also, using these experiences from this program, more SC could be constructed that is beneficial to the safety and health of Chinese people.  相似文献   
602.
以回用为目标的污水深度处理组合工艺及其发展   总被引:9,自引:0,他引:9  
邓耀杰  李平  朱凡  罗丹 《环境工程》2005,23(3):10-14
通过对现有各种污水回用深度处理工艺进行归纳整理,概要介绍了国内外城市污水回用深度处理传统工艺及其发展状况,重点阐述了膜分离技术与污水深度处理工艺的集成与组合在污水回用中的应用,指出了污水回用工艺的优化组合与集成对缓解淡水资源短缺、实施水资源的可持续利用具有深远的战略意义。  相似文献   
603.
微生物絮凝剂产生菌的絮凝性能   总被引:7,自引:0,他引:7  
张旭  徐恒  邓宇  袁媛  张辉  胡国全 《化工环保》2005,25(2):152-155
从废水处理厂和土壤中分离产絮凝剂的菌株,其中一株产絮凝剂的细菌W7—1对高岭土的絮凝活性达94%,初步鉴定该菌为Klebiella sp.,W7—1对产絮凝剂的培养条件要求简单,产絮凝剂的最佳碳源和氮源为蔗糖和牛肉膏,pH在5~10的范围内都适应絮凝剂的产生,但pH为8.0时絮凝活性最高。絮凝剂的添加量为10mL/L、絮凝体系pH为7~10时絮凝活性好,提纯后的絮凝剂产量高于其它絮凝剂近10倍,分析表明,絮凝剂成分为多糖,且有很好的热稳定性,加热至100℃、30min后絮凝活性不变。  相似文献   
604.
絮凝剂XN98处理油田聚合物驱含油污水   总被引:12,自引:5,他引:7  
通过筛选复配得到絮凝剂XN98,该絮凝剂由五种成分组成,其中以无机絮凝剂为主,含有少量有机絮凝剂。该絮凝剂处理油田聚合物驱含油污水效果良好,絮凝剂用量为50 mg/L时,处理后水质可以达到中、高渗透层含聚污水处理指标。絮凝剂XN98处理聚合物驱污水的药剂成本约为0.2元/t,约为PAC(聚铝)的三分之一。  相似文献   
605.
高峰矿提升机用钢丝绳无损检测方法的研究   总被引:1,自引:0,他引:1  
介绍了利用漏磁场原理检测钢丝绳断丝 ,磁桥回路测量钢丝绳磨损信号 ,并实现在一个传感器中对上述多种缺陷的综合检测。在信号处理方面 ,结合不同信号特征 ,设计了相应的电路和处理软件 ,实现了缺陷的定量检测  相似文献   
606.
The roots of Populus euphratica, a plant that grows in the lower reaches of the Tarim River, Northwest China, exhibit a significant level of hydraulic redistribution; however, quantitative assessments of the water-sharing process and its ecological effects are limited. This study was designed to obtain such data using an assessment model based on field observation parameters, including soil water content (soil water potential), root distribution, and stable isotope δ18O values of soil and plant samples during the entire growing season. The results showed that hydraulic redistribution in P. euphratica can be detected in 0–120 cm soil layers, with the amount of hydraulically redistributed water (HRW) in the soil found at different depths as follows: 60–80?>?40–60?>?20–40?>?0–20?>?80–100?>?100–120 cm. The variations in HRW in soil layers can be partly attributed to the vertical distribution of roots. The denser roots found at greater depths positively influenced the amount of redistributed water in lower soil layers. During the growing season, the amount of HRW reached a daily average of 0.27 mm, which allowed increased transpiration and provided an adequate water supply to herbs. Based on the stable isotope (δ18O) data, the amount of HRW provided by the roots of P. euphratica could meet 22–41 % of its water demand.  相似文献   
607.
In this study, the longitudinal distribution of heavy metals (including As, Cd, Cr, Cu, Ni, Pb, and Zn) from sediment of a 70-km long canyon reservoir in Yunnan Province was investigated and their potential ecological risks were assessed. The results indicated that the concentration of all the detected metals in the sediments that was sampled near the dam was much higher than that sampled from upstream far from the dam. The geoaccumulation index (I geo) and contamination factors (CF) suggested that Cd was the most important contamination factor, followed by As and Zn, while the concentration of Cr, Cu, Ni, and Pb was at uncontaminated levels. Cd posed a high potential ecological risk in the sediment. Furthermore, potential ecological risk is significantly correlated with the distance from the dam.  相似文献   
608.
Abstract

Population, resources and environment constitute the basis for economic and social advances. Their coordinative development is the key factor for the continuous, stable and harmonious development of economy and society. China is a developing country which needs to mobilize the whole society to coordinate among population, resources and environment and to keep publicity and research in pace so as to deepen people's understanding and improve the methods of achieving this coordination.  相似文献   
609.
Abstract

Population, resources, environment and socio-economic development are four major issues of increasing world attention today and are also four major factors constraining China's development tomorrow. Through an analysis of the international situation and an assessment of China's actual conditions, this article proposes a basic framework and conception of promoting the sustainability of China's population, resources, environment and socio-economic development.  相似文献   
610.
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