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   113篇
  免费   13篇
  国内免费   26篇
安全科学   31篇
环保管理   21篇
综合类   44篇
基础理论   18篇
污染及防治   23篇
评价与监测   9篇
社会与环境   3篇
灾害及防治   3篇
  2023年   2篇
  2022年   1篇
  2021年   7篇
  2020年   8篇
  2019年   10篇
  2018年   3篇
  2017年   5篇
  2016年   10篇
  2015年   4篇
  2014年   4篇
  2013年   14篇
  2012年   9篇
  2011年   7篇
  2010年   10篇
  2009年   13篇
  2008年   4篇
  2007年   7篇
  2006年   11篇
  2005年   4篇
  2003年   2篇
  2002年   2篇
  2000年   3篇
  1999年   1篇
  1998年   4篇
  1997年   1篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1985年   1篇
  1982年   1篇
  1980年   1篇
排序方式: 共有152条查询结果,搜索用时 406 毫秒
121.
采用液相还原法制备焙烧高岭土负载纳米铁镍双金属(CK-Fe/Ni)。考察了在不同条件下,如pH、投加量、初始浓度、温度等,对负载型纳米铁镍双金属降解水中偶氮染料直接耐晒黑G的影响及动力学研究。结果表明:在pH=9.49、温度为30℃、负载型纳米铁镍双金属的投加量为1.05 g/L、搅拌速度为60 r/min,经过20 min反应后,负载型纳米铁镍双金属降解水中偶氮染料直接耐晒黑G的去除率达到了99.98%。吸附和电镜表征结果表明,作为载体的焙烧高岭土起着吸附直接耐晒黑G和分散纳米铁镍双金属颗粒的作用导致反应活性提高。降解动力学数据表明,负载型纳米铁镍双金属对直接耐晒黑G的降解过程符合伪一级反应动力学规律,速率常数k随负载型纳米铁镍双金属的投加量的增加而提高,表观活化能为19.72 kJ/mol。最后,利用高岭土负载纳米铁镍双金属对废水处理,结果表明,负载型纳米铁镍双金属在实际废水中对直接耐晒黑G的去除率达到了99.98%。  相似文献   
122.
为了研究2016年二十国集团领导人峰会(G20峰会)期间长三角区域臭氧(O3)变化特征,评估管控措施对O3浓度的影响,利用2016年8月10日至9月20日杭州及周边地区的空气质量监测数据、气象数据以及排放清单数据,分析了O3和NO2浓度及气象条件的时空分布特征,研究了不同管控区域不同保障时期O3浓度的时空变化和O3敏感控制区的改变。结果表明:峰会保障期间对于一次排放污染物和细颗粒物的管控措施效果明显,但核心区的O3质量浓度高于严控区和管控区,分别高出11. 2、9. 2μg/m^3。日间的NOx管控导致O3日变化幅度增高接近50μg/m^3。在峰会保障期间,卫星数据和站点观测结果显示核心区O3由VOCs控制区转为NOx-VOCs协同控制区,整个长三角区域的O3生成对于NOx排放量更为敏感。管控措施越强,核心区的O3生成对于NOx排放越敏感,且O3浓度与NOx浓度的相关性越强。对NOx和VOCs的协同控制降低排放,是关系O3浓度管控的一项重要工作。  相似文献   
123.
G20峰会期间杭州市大气区域输送特征研究   总被引:1,自引:0,他引:1  
利用拉格朗日扩散模型评估G20峰会期间杭州市大气区域输送特征,结果表明,G20峰会开幕期间杭州市的气团来源由西南内陆转为杭州湾和东海地区,且传输速度较快,空气污染得到显著清除。保障期间污染情形下,苏北、安徽、江西等地的气团输送更强,浙北和苏南地区输送减弱。在管控情形下,浙北的PM2.5一次排放潜在贡献降低了15%,减排管控措施有效降低了周边地区一次排放对杭州市的空气污染输送。1981—2016年G20峰会历史同期,浙江省对杭州市的气团贡献年际变化幅度为26%~85%,平均贡献为63%。  相似文献   
124.
This article re‐examines the persistence in natural gas consumption using an alternative methodology. We compare the results of traditional panel unit root tests with those provided by Bahmani‐Oskooee et al., which allow for both sharp and smooth breaks. Our analysis uses data for the G7 countries over the 1965–2016 years. The empirical findings show that while traditional unit root tests with sharp breaks lean towards the non‐stationarity of the series for all the G7 countries, modeling breaks in our unit root testing methodology can assert that natural gas consumption is non‐stationary only for Canada, France, Italy, and USA. These results imply that, for the majority of our sample, energy demand management policies designed to shrink energy consumption will have temporary effects, as energy consumption will return to its trend path.  相似文献   
125.
Post-disaster reconstruction (PDR) poses specific and complex challenges that government agencies have to deal with. Existing crisis management and communication models as well as literature on social media adoption by public organisations tend to focus on the critical stage, neglecting the issues that arise when the social, physical and cultural environments affected by a disaster have to be rebuilt. Conversely, this paper presents some preliminary findings on the Government to Citizen (G2C) communications and social media usage in PDR settings. The PDR process that followed the earthquakes in Emilia-Romagna (Northern Italy) in 2012 was used as a case study. Data derived from field notes and multiple-choice questionnaires revealed that government agencies provided information mainly about housing and infrastructure and financing and that they addressed this information to all citizens, although information was sometimes targeted specifically to business people, homeowners and members of community-based groups. Government officers gave preference to face-to-face contacts, Web portals and printed material. Social media were used predominantly as additional means of communication of PDR-related information, thus underrating their potential for community engagement and G2C bidirectional communication. In the discussions, findings are integrated into and validated against literature and communication theories.  相似文献   
126.
电-Fenton法降解青霉素的动力学研究   总被引:1,自引:0,他引:1  
黄昱  李小明  杨麒  曾光明  张振 《环境化学》2007,26(5):618-621
采用电-Fenton法处理青霉素钠(Penicillin G sodium, PGN)模拟废水,当T=20℃,pH=3时,投加0.5g·l-1 FeSO4和0.2ml·l-1 H2O2,在0.6A电流下降解青霉素钠废水(100 mg·l-1), 20min后青霉素钠去除率为79%,40min后去除率为95%.拟合实验数据得到青霉素钠降解反应的速率方程式为:-d[PGN]/dt=2.35×106 exp(-32869.4/RT )[Fe2 ]0.53[H2O2]0.8[PGN]1.14反应速率常数和反应级数表明,初始阶段降解反应进行非常迅速,且H2O2浓度比Fe2 浓度对电-Fenton降解反应的影响重要.  相似文献   
127.
该文设计了一种基于3G的无线视频监控系统.论述了系统的基本组成及相关工作原理.重点对系统应用的关键技术进行了详细分析.该系统具有压缩比高、布线灵活、经济高效的特点.系统能实现复杂环境下的视频监控.  相似文献   
128.
Ahmad MK  Mahmood R 《Chemosphere》2012,87(7):750-756
Potassium bromate (KBrO3) is a widely used food additive, a water disinfection by-product and a known nephrotoxic agent. The effect of KBrO3 on rat blood, especially on the anti-oxidant defense system, was studied in this work. Animals were given a single oral dose of KBrO3 (100 mg/kg body weight) and sacrificed 12, 24, 48, 96 and 168 h after this treatment. Blood was collected from the animals and separated into plasma and erythrocytes. KBrO3 administration resulted in increased lipid peroxidation, protein oxidation, hydrogen peroxide levels and decreased the reduced glutathione content indicating the induction of oxidative stress in blood. Methemoglobin levels and methemoglobin reductase activity were significantly increased while the total anti-oxidant power was greatly reduced upon KBrO3 treatment. Nitric oxide levels were enhanced while vitamin C concentration decreased in KBrO3 treated animals. The activities of major anti-oxidant enzymes were also altered upon KBrO3 treatment. The maximum changes in all these parameters were 48 h after the administration of KBrO3 and then recovery took place. These results show for the first time that KBrO3 induces oxidative stress in blood and impairs the anti-oxidant defense system. Thus impairment in the anti-oxidant power and alterations in the activities of major anti-oxidant enzymes may play an important role in mediating the toxic effects of KBrO3 in the rat blood. The study of such biochemical events in blood will help elucidate the molecular mechanism of action of KBrO3 and also for devising methods to overcome its toxic effects.  相似文献   
129.
Gölcük Nature Park (GNP) is an area protected by law in Turkey. It is an important nature park with rich flora, fauna, geomorphologic forms, landscape features, and recreational potential in the region. However, GNP does not have a recreation management plan. The purpose of this study was to determine the actual natural, cultural, and visual resources of GNP, determine the most suitable recreational sites with multiple factors, evaluate the demands and tendencies of visitors, and suggest recreational activities and facilities for the most suitable sites of GNP. However, it was also conceived as leading to a recreational plan and design of GNP in the future and identifying the entire appropriate and current data of GNP with the creation of various maps. This study used multifactor analysis to determine the most suitable recreation sites of GNP. Used recreation factors were established including degree of slope, proximity to water resources, accessibility, elevation, vegetation, soil, climate, aspect, current cultural facilities, visual values, and some limiting factors in accordance with the characteristics of GNP. Weighting and suitability values of factors were determined by 30 local expert surveys. All obtained data were evaluated and integrated in the Geographical Information Systems base. Obtained maps were overlapped. Thus, recreational suitability zones map were created manually. However, the demands and behaviours from visitor surveys in GNP were focused on the most suitable recreation sites of the park. Finally, 10% of GNP was identified as the most suitable sites for recreational use. Various recreational facilities and activities (including picnicking, sports facilities and playgrounds, camping sites, walking paths, food and local outlets, etc.) were recommended for nine of the most suitable areas on the proposed recreational map.  相似文献   
130.
研究了在HAC-NaAC介质中,痕量铬(VI)催化过氧化氢氧化罗丹明6G的褪色反应及其动力学条件,建立了催化荧光测定痕量铬(VI)的新方法。催化反应在沸水浴中进行15min,为假零级反应。方法的检出限为2.1×10-9g/mL,线性范围为0.2~2.5μg/25mL。将该法用于环境水样中痕量铬(VI)的测定,结果良好。  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