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   1248篇
  免费   15篇
  国内免费   150篇
安全科学   39篇
废物处理   71篇
环保管理   111篇
综合类   293篇
基础理论   274篇
污染及防治   465篇
评价与监测   83篇
社会与环境   63篇
灾害及防治   14篇
  2023年   5篇
  2022年   46篇
  2021年   16篇
  2020年   10篇
  2019年   20篇
  2018年   80篇
  2017年   30篇
  2016年   46篇
  2015年   47篇
  2014年   48篇
  2013年   104篇
  2012年   49篇
  2011年   84篇
  2010年   74篇
  2009年   66篇
  2008年   76篇
  2007年   95篇
  2006年   69篇
  2005年   39篇
  2004年   76篇
  2003年   52篇
  2002年   35篇
  2001年   98篇
  2000年   43篇
  1999年   19篇
  1998年   10篇
  1997年   12篇
  1996年   12篇
  1995年   10篇
  1994年   8篇
  1993年   6篇
  1992年   2篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1988年   4篇
  1987年   2篇
  1986年   1篇
  1984年   1篇
  1981年   1篇
  1980年   1篇
  1977年   1篇
  1976年   1篇
  1964年   1篇
  1960年   1篇
  1951年   1篇
排序方式: 共有1413条查询结果,搜索用时 140 毫秒
11.
羧甲基壳聚糖及复合絮凝剂对染料废水的脱色研究   总被引:1,自引:0,他引:1  
用羧甲基壳聚糖(CMCTS)复合聚合氯化铝(PAC)对分子量较小的活性染料模拟废水进行脱色处理,结果表明,引入PAC作为助凝剂的脱色效果优于单纯使用CMCTS。处理染料废水的最佳pH为5,CMCTS的投加量为90mg/L,PAC的投加量为2.5mg/L,此优化条件下,染料废水的脱色率可达93.4%,COD去除率达88.5%。  相似文献   
12.
Small- and medium-sized enterprises (SMEs) play an important role in sustainable development not only for their significant contribution to China’s economy, but also for their large share of total discharged pollutants. Therefore, this research takes the enterprises in Suzhou Industrial Park, China as the case study to investigate the environmental management practices of SMEs, and identify drivers and barriers to engaging businesses in environmental management initiatives. It is shown that, as in other countries, SMEs are less active in adopting environmental management initiatives than larger companies. Legislation remains the key driver to engage SMEs in environmental management initiatives. Based on the analysis, policy recommendations are also presented.  相似文献   
13.
高精度管道泄漏监测报警定位系统是基于管理中心平台上集成了次声波泄漏监测定位技术、最新的卫星定位技术和通讯技术为一体的管道泄漏监测系统.通过在孤东采油厂原油外输线的研发应用,能够准确的监测到原油管线泄漏点,为打击盗油行为,提供了有力保障.  相似文献   
14.
根据在海外钻井工程服务项目HSE管理中积累的经验,介绍了国外防翻架的安全标准及其设计、选材、制作和安装要求,为中国油田服务承包商进行轻型车辆防翻架制作提供了参考。  相似文献   
15.
Five aromatic hydrocarbons (benzene, toluene, and three isomeric xylenes) were monitored in indoor and outdoor air of 7 public buildings and 54 private homes, located in Barcelona City metropolitan area and in several rural areas of Catalonia. The sampling was carried out over four periods: spring-summer and winter of 2000, and summer and winter of 2001. Passive ORSA 5 Dra¨ger samplers were used for benzene, toluene, and xylenes (BTX) adsorption. BTX were extracted with carbon disulphide and analysed using ...  相似文献   
16.
利用反渗透工艺对冷轧废水生化处理废水进行处理,获得了较好的脱盐效果。选取进水含盐量、回收率、pH值对系统脱盐率的影响。结果表明:当进水电导率为1 360μs/cm时,系统脱盐率可达94.7%;进水电导率为3 353μs/cm时,系统脱盐率为85.9%。当系统回收率低于77%时,除盐率受其影响较小在90%左右,但是若进一步增加系统回收率,则脱盐效果显著下降。当进水pH值越高脱盐效果越高,但为降低结垢风险,本系统进水pH值控制在7.1左右。  相似文献   
17.
A new type of sponge iron sphere (NSIS) with 1-5 mm diameter, made of concentrated iron powder and possessed high activity and intension, was prepared by mini-pellet sintering integrated with H2 direct reduction. Static state experiment has been carried on to investigate the Cd2+ removal efficiency from wastewater by the NSIS and to explore the Cd2+ removal reaction kinetics. It was suggested that initial pH value and Cd2+ original concentration had significant influence on Cd2+ removal percentage. Cd2+ removal percentage decreased significantly with the increasing of Cd2+original concentration whether the original pH value be adjusted to 3.0 or without adjustment. The results showed that the Cd2+ removal process followed the first order reaction because the reaction order was from 0.803 to 0.996. The apparent reaction rate constant between Cd2+ and NSIS was from 0.0025 to 0.1000 (mg·L?1)1-n·min?1. Compared with SIS reduced by charcoal reduction, NSIS deoxided by hydrogen possessed higher activity, and could remove the same quantity of Cd2+ within a shorter period of time.  相似文献   
18.
19.
The efficiency of aided phytostabilization using organic amendments such as ramial chipped wood (RCW) and composted sewage sludge (CSS) was studied on contaminated techno-soils, on nine experimental plots. The objective was to characterize the role of fulvic (FA) and humic acids (HA) on the mobilization of trace elements, specifically As, Cu, Mo, Pb and Zn. Results showed that the addition of CSS increased the total organic carbon and nitrogen content more than with RCW and as a result, the C/N ratio in the CSS soil was higher than in the RCW and non-amended (NE) soil, reflecting the high decomposition of soil organic matter in the CSS soil compared with the other soils. The RCW and CSS amendments increased the hydrogen index (HI) values and the oxygen index (OI) values compared with the NE soil, especially for the soil treated with CSS which contained more aliphatic than aromatic compounds. The addition of CSS to the techno-soil significantly increased the percentage of C org associated with the HA fractions compared with the RCW and NE soils. The soil amended with CSS showed the highest E 4/E 6 ratio and the lowest E 2/E 3 ratio of FA. Zn and As were more abundant in the FA fraction than in the HA fraction, whereas Pb, Cu and Mo were more associated to HA than to FA in the treated and untreated soils, which may explain the difference in their mobility and availability.  相似文献   
20.
杨波  毕深涛  李方  田晴 《环境工程学报》2014,(10):4273-4279
应用自主研制的强化循环厌氧反应器(SCAR)中试规模处理实际印染废水,研究反应器的启动特性。反应器接种厌氧颗粒污泥后启动运行83 d,形成连续内循环并实现了对印染废水处理的高效稳定运行。在进水COD浓度1 000~3 650 mg/L、系统容积负荷0.7~6.4 kg/(m3·d)条件下,废水COD和色度平均去除率分别达到55%和73%。反应器内较高浓度的NH+4-N保证了系统pH的稳定性,350~600 mg/L的NH+4-N浓度没有对强化循环厌氧反应器产生抑制作用,系统内也没有出现VFA(以乙酸计)积累。启动过程中,厌氧颗粒污泥的粒径增大、沉降性能变好。启动实验完成时,反应器内微生物的脱氢酶活性(以TF计)和辅酶F420浓度分别为3.4973 mg/(g·h)和0.1872μmol/g。  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