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   757篇
  免费   81篇
  国内免费   642篇
安全科学   110篇
废物处理   12篇
环保管理   41篇
综合类   874篇
基础理论   327篇
污染及防治   58篇
评价与监测   11篇
社会与环境   12篇
灾害及防治   35篇
  2024年   10篇
  2023年   25篇
  2022年   38篇
  2021年   33篇
  2020年   34篇
  2019年   24篇
  2018年   27篇
  2017年   20篇
  2016年   22篇
  2015年   47篇
  2014年   122篇
  2013年   50篇
  2012年   59篇
  2011年   32篇
  2010年   28篇
  2009年   103篇
  2008年   113篇
  2007年   58篇
  2006年   30篇
  2005年   44篇
  2004年   20篇
  2003年   26篇
  2002年   11篇
  2001年   26篇
  2000年   9篇
  1999年   40篇
  1998年   56篇
  1997年   46篇
  1996年   64篇
  1995年   71篇
  1994年   52篇
  1993年   36篇
  1992年   19篇
  1991年   52篇
  1990年   1篇
  1989年   30篇
  1988年   1篇
  1987年   1篇
排序方式: 共有1480条查询结果,搜索用时 421 毫秒
51.
ProgresintheresearchonaquaticenvironmentalnonpointsourcepolutioninChinaBaoQuansheng,MaoXianqiang,WangHuadongInstituteofEnviro...  相似文献   
52.
EffectsoflowpHonzooplanktoninsomesuburbanwaterbodiesofChongqingCityZhuangDehui(InstituteofHydrobiology,ChineseAcademyofScienc...  相似文献   
53.
通过测定液体与废白土粉末之间的接触角及液体与蜡之间的液液界面张力,对水基表面活性剂乳液的溶剂及配方进行了优选,得到最佳的水基面活性剂乳液的组成为:质量分数0.2%的十二烷基苯磺酸钠+体积分数为2.5%的乙醇+体积分数为25%的混合烃(正己烷+苯,等体积)+体积分数为72.5%的水。实验证明,用该水基表面活性剂乳液处理废白土,蜡的回收率可达80%,同时不破坏白土的颗粒结构。  相似文献   
54.
Climatic change and urbanization effect in China during the last 39 years were investigated. It is found that a warming of about 0.23℃ for the annual temperature has been noticed from 1951 to 1989. The warmings of about 0.78 ℃ in winter and 0.34 3℃ in spring have been shown. It is also presented that a cooling of about -0.27℃ in summer has been indicated. The bigger cities are warmer than smaller cities in China. The dried trends in the annual precipitation during the last 39 years were presented. The precipitation decreased obviously in summer all over China. The bigger cities were drier than smaller cities.  相似文献   
55.
Two strains of bacteria were isolated from nitrile polluted soils, and identified as Corynebacterium boffmanii and Arthrobacter flavescens. Acetonitrile, propionitrile, butyronitrile and acrylonitrile were degraded by these bacteria to yield corresponding amides, carboxylic acids and ammonia. The nitrile-degrading abilities of these strains were investigated. The removal rates for the nitrile were nearly 100%, after these bacteria were grown in medium containing 10000 ppm of aceto-, propio-, or butyronitrile at 28 ℃ for 24h. When the reaction mkture consisting of 5000 ppm of above mentioned nitriles or acrylonitrile and 20g (dry cell) /L resting cells of the two strains in 0.06mol/L phosphate buffer (pH7.5) was incubated separately at 25 ℃ with moderate shaking for 15 or 45 min, the nitrile could be degraded completely. The optimum growth conditions for C.hoffmanii and A.flavescens were studied as well.  相似文献   
56.
plane decaying leaves have been found capable of removing chromium and nickel ions from aqueous solutions. The removal efficiency depends upon the pH conditions, ions components and concentrations, and concentrations of leaves in media. The maximum removal for unique Cr6+ is about 7.5-8.0g/kg leaves at pH 4. 0, for unique Ni2+ about 2. 6g/kg at the region of PH5. 0-5.5. Under the described conditions nickel increases chromium uptake by plane decaying leaves from solution.  相似文献   
57.
PurificationandreclamationofwastewaterbyanintegratedbiologicalpondsystemWuZhenbin;XiaYicheng;ZhangYongyuan;DengJiaqi;ChenXita...  相似文献   
58.
Theresearchofbelow-cloudscavengingofrainwaterinGuilinCityBaiYuhua;YaoRongkui;LiXin;TangXiaoyan(TheDepartmentofTechnicalPhysie...  相似文献   
59.
The fluxes of heavy metals and magnetite, a fly-ash component, from coal burning, to sediments of the Kunming Lake in Beijing have increased measurably over the last fifty years. Ages were introduced to the sediment strata through Pb-210 geochronologies. Even with a doubling of coal usage by the year 2000, the anthropogenic metal fluxes will still be less than those recorded in metropolitan Tokyo and U.S. lakes.  相似文献   
60.
Dunaliella tertiolecta has an ability to biodegrade dimethyl phthalate(DMP) was found in this study, and the average of the biodegradation rates were 11.3 mg/(L·d) and 30.5 mg/(L·d), and the average of the phthalic acid (PA) production rates were 1.5 mg/(L·d) and 3.6 mg/(L·d), for initial 100 mg/L and 300 mg/L DMP, respectively. The larger amount of accumulation by D. tertiolecta under higher DMP concentration may be responsible for the increase of biodegradation rate, and one of products of DMP biodegradation by D. tertiolecta may be PA. By fitting the process of DMP biodegradation by D. tertiolecta with a kinetic equation newly suggested, the standard deviations between calculated and observed values were 2.5 mg/L and 5.7 mg/L, respectively.  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