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   163篇
  免费   7篇
  国内免费   50篇
安全科学   3篇
废物处理   11篇
环保管理   14篇
综合类   98篇
基础理论   46篇
污染及防治   40篇
评价与监测   8篇
  2023年   5篇
  2022年   5篇
  2021年   6篇
  2020年   9篇
  2019年   6篇
  2018年   8篇
  2017年   6篇
  2016年   6篇
  2015年   8篇
  2014年   11篇
  2013年   21篇
  2012年   8篇
  2011年   12篇
  2010年   7篇
  2009年   7篇
  2008年   14篇
  2007年   19篇
  2006年   7篇
  2005年   6篇
  2004年   5篇
  2003年   6篇
  2002年   8篇
  2001年   1篇
  2000年   4篇
  1999年   7篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1994年   1篇
  1993年   2篇
  1991年   2篇
  1990年   3篇
  1989年   3篇
  1984年   1篇
  1981年   1篇
排序方式: 共有220条查询结果,搜索用时 12 毫秒
101.
New approaches to characterizing urban air particles in central London   总被引:2,自引:0,他引:2  
1 IntroductionOnaninternationalscale,thenatureofurbanairpollutionhaschangedsignificantlyoverthelast50years.Inthe1950sand1960s,themostimportantenvironmentalhealthissuesstemmedfromtheoccurrenceofurbansmogs,anatmosphericcocktailcharacterizedbyhighconcen…  相似文献   
102.
成都电厂电子束烟气脱硫示范工程处理该厂200MW机组锅炉的30万Nm^2/h烟气。其脱硫率及脱硝率均超过80%及10%设计值,处理过程为干法,无废水废渣,副产品硫铵可用作化肥,过程对烟气SO2浓度及烟气量的变化有较好的适应性和负荷跟踪性。  相似文献   
103.
Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state 13C nuclear magnetic resonance spectroscopy (13C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants.  相似文献   
104.
Ru(Ⅲ) was employed as catalyst for aniline oxidation by permanganate at environmentally relevant pH for the first time. Ru(Ⅲ) could significantly improve the oxidation rate of aniline by 5-24 times with its concentration increasing from 2.5 to 15 μmol/L. The reaction of Ru(Ⅲ) catalyzed permanganate oxidation of aniline was first-order with respect to aniline, permanganate and Ru(Ⅲ), respectively. Thus the oxidation kinetics can be described by a third-order rate law. Aniline degradation by Ru(Ⅲ) catalyzed permanganate oxidation was markedly influenced by pH, and the second-order rate constant (ktapp) decreased from 643.20 to 2.67 (mol/L)^-1 sec^-1 with increasing pH from 4.0 to 9.0, which was possibly due to the decrease of permanganate oxidation potential with increasing pH. In both the uncatalytic and catalytic permanganate oxidation, six byproducts of aniline were identified in UPLC-MS/MS analysis. Ru(Ⅲ), as an electron shuttle, was oxidized by permanganate to Ru(Ⅵ) and Ru(Ⅶ), which acted the co-oxidants for decomposition of aniline. Although Ru(Ⅲ) could catalyze permanganate oxidation of aniline effectively, dosing homogeneous Ru(Ⅲ) into water would lead to a second pollution. Therefore, efforts would be made to investigate the catalytic performance of supported Ru(Ⅲ) toward permanganate oxidation in our future study.  相似文献   
105.
Various studies have been conducted in the past on the fresh waters related to the various aspects of limnology, physico-chemistry, primary productivity, plankton etc. in relation to environmental conditions and ecology, flora and fauna of River Ganga. In the present investigation some recent approach have been made to study the various parts of fishes like gill structures, scales for age determination, length and weight of fish for growth assessments etc. The SEM study of scales in relation to pollution and environmental conditions is a recent approach. At this stage, in the present study the scales of two most common fishes found in the study stretch were involved to create a base line.  相似文献   
106.
A source apportionment study was carried out to estimate the contribution of motor vehicles to ambient particulate matter (PM) in selected urban areas in the USA. Measurements were performed at seven locations during the period September 7, 2000 through March 9, 2001. Measurements included integrated PM2.5 and PM10 concentrations and polycyclic aromatic hydrocarbons (PAHs). Ambient PM2.5 and PM10 were apportioned to their local sources using the chemical mass balance (CMB) receptor model and compared with results obtained using scanning electron microscopy (SEM). Results indicate that PM2.5 components were mainly from combustion sources, including motor vehicles, and secondary species (nitrates and sulfates). PM10 consisted mainly of geological material, in addition to emissions from combustion sources. The fractional contributions of motor vehicles to ambient PM were estimated to be in the range from 20 to 76% and from 35 to 92% for PM2.5 and PM10, respectively.  相似文献   
107.
• 4-chlorophenol biodegradation could be enhanced in Fe2O3 coupled anaerobic system. • Metabolic activity and electron transport could be improved by Fe2O3 nanoparticles. • Functional microbial communities could be enriched in coupled anaerobic system. • Possible synergistic mechanism involved in enhanced dechlorination was proposed. Fe2O3 nanoparticles have been reported to enhance the dechlorination performance of anaerobic systems, but the underlying mechanism has not been clarified. This study evaluated the technical feasibility, system stability, microbial biodiversity and the underlying mechanism involved in a Fe2O3 nanoparticle-coupled anaerobic system treating 4-chlorophenol (4-CP) wastewater. The results demonstrated that the 4-CP and total organic carbon (TOC) removal efficiencies in the Fe2O3-coupled up-flow anaerobic sludge blanket (UASB) were always higher than 97% and 90% during long-term operation, verifying the long-term stability of the Fe2O3-coupled UASB. The 4-CP and TOC removal efficiencies in the coupled UASB increased by 42.9±0.4% and 27.5±0.7% compared to the control UASB system. Adding Fe2O3 nanoparticles promoted the enrichment of species involved in dechlorination, fermentation, electron transfer and acetoclastic methanogenesis, and significantly enhanced the extracellular electron transfer ability, electron transport activity and conductivity of anaerobic sludge, leading to enhanced 4-CP biodegradation performance. A possible synergistic mechanism involved in enhanced anaerobic 4-CP biodegradation by Fe2O3 nanoparticles was proposed.  相似文献   
108.
电子束法是一种能够同时脱硫、脱硝的烟气处理方法,具有脱硫、脱硝率高,副产品能够有效综合利用,不产生二次污染的特点,是一种先进的烟气处理技术。  相似文献   
109.
常温ANAMMOX工艺运行性能及功能菌研究   总被引:3,自引:0,他引:3       下载免费PDF全文
通过改变进水基质浓度,对以火山岩为填料的常温上向流厌氧氨氧化生物滤池在不同基质浓度下的脱氮性能进行了研究.借助显微镜、电镜(SEM)观察对滤池内的微生物形态进行了分析,利用变性凝胶电泳(DGGE)和克隆测序等微生物方法,对ANAMMOX种属进行了鉴定.试验结果表明,常温条件下,厌氧氨氧化滤池在高、低不同基质下都能够保持较高的脱氮效果,其中TN去除负荷最高能够达到2.99kgN/(m3×d),NH4+-N和NO2--N最高去除率分别能够达到99.4%和98.8%;显微镜、电镜观察显示:滤池下部的微生物种类更丰富,ANAMMOX菌在滤池的中部和上部的比例更高;16SrRNA克隆测序鉴定结果表明:滤池中的ANAMMOX菌为Candidatus Kuenenia stuttgartiensis,其对温度和基质浓度都有着较宽的适应性.  相似文献   
110.
对不同Al/SO2-4比及碱化度条件下PACl与SO42-的反应过程进行研究,分析了体系中总铝浓度及形态分布变化规律,测定了各沉淀/结晶产物的组成,并对其形貌进行了扫描电镜观察.实验结果表明:碱化度对PACl/SO42-反应体系有较大影响,随着碱化度(B值)的增加,沉淀/结晶的析出速率加快,结果析出物中OH含量逐渐增加,而SO42-/Al比率从0.45~0.30逐渐降低.各聚合铝水解形态与SO42-反应速率上存在明显差异,从而为其混凝优势形态的分离纯化创造了条件.  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