全文获取类型
收费全文 | 304篇 |
免费 | 20篇 |
国内免费 | 83篇 |
专业分类
安全科学 | 28篇 |
废物处理 | 23篇 |
环保管理 | 16篇 |
综合类 | 176篇 |
基础理论 | 64篇 |
污染及防治 | 59篇 |
评价与监测 | 24篇 |
社会与环境 | 12篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 3篇 |
2023年 | 3篇 |
2022年 | 17篇 |
2021年 | 12篇 |
2020年 | 22篇 |
2019年 | 7篇 |
2018年 | 14篇 |
2017年 | 16篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 22篇 |
2012年 | 20篇 |
2011年 | 30篇 |
2010年 | 27篇 |
2009年 | 24篇 |
2008年 | 28篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 15篇 |
2001年 | 17篇 |
2000年 | 10篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有407条查询结果,搜索用时 31 毫秒
181.
试论环境影响评价中的公众参与 总被引:2,自引:0,他引:2
环境影响评价是我国环保领域的基本制度之一,公众参与在环评中的作用是不可替代的.本文从公众参与的发展沿革、法律规定等方面进行了具体阐述,并根据作者在环评工作中的实例总结了有关公众参与的体会和心得. 相似文献
182.
介绍了快速成形技术的工艺过程、应用及几种典型的快速成形工艺 ,并分析了影响其精度和速度的普遍存在的问题及进展 相似文献
183.
184.
Kinetic analysis of photocatalytic oxidation of gas-phase formaldehyde over titanium dioxide 总被引:4,自引:0,他引:4
Degradation of formaldehyde with different initial concentration over titanium dioxide was carried out in a photocatalytic reactor. Photocatalytic rates were well described by the simplified Langmuir-Hinshelwood model. The kinetic analysis shows that the apparent first-order reaction coefficient is lower and half-life of photocatalysis is longer for low concentration than for high concentration formaldehyde. A network formation model of the photocatalytic products was established. Experimental results and analysis demonstrate that carbon dioxide concentration and carbon monoxide concentration in gas phase vary exponentially with the illumination time and may be even higher than gas-phase formaldehyde concentration if there is much pre-adsorbed formaldehyde in adsorption equilibrium on catalysts before illumination. Carbon monoxide is found to be one of the by-products during formaldehyde photooxidation. 相似文献
185.
186.
Due to the low concentration of indoor air contaminants,photocatalytic technology shows low efficiency for indoor air purification.The application of TiO_2 for photocatalytic removal of formaldehyde is limited,because TiO_2 can only absorb ultraviolet(UV) light.Immobilization of TiO_2 nanoparticles on the surface of graphene can improve the visible light photocatalytic activity and the adsorption capacity.In this study,rGO(reduced graphene oxide)/TiO_2 was synthesized through a hydrothermal method using titanium tetrabutoxide and graphene oxide as precursors,and was used for the degradation of low concentration formaldehyde in indoor air under visible light illumination.Characterization of the crystalline structure and morphology of rGO/TiO_2 revealed that most GO was reduced to rGO during the hydrothermal treatment,and anatase TiO_2 nanoparticles(with particle size of 15–30 nm) were dispersed well on the surface of the rGO sheets.rGO/TiO_2 exhibited excellent photocatalytic activity for degradation of formaldehyde in indoor air and this can be attributed to the role of rGO,which can act as the electron sink and transporter for separating photo-generated electron–hole pairs through interfacial charge transfer.Furthermore,rGO could adsorb formaldehyde molecules from air to produce a high concentration of formaldehyde on the surface of rGO/TiO_2.Under visible light irradiation for 240 min,the concentration of formaldehyde could be reduced to 58.5 ppbV.rGO/TiO_2 showed excellent moisture-resistance behavior,and after five cycles,r GO/TiO_2 maintained high photocatalytic activity for the removal of formaldehyde(84.6%).This work suggests that the synthesized rGO/TiO_2 is a promising photocatalyst for indoor formaldehyde removal. 相似文献
187.
188.
THK引气气浮系统的研制与应用 总被引:5,自引:0,他引:5
在引进美国THK系统基础上,通过对THK系统的研究,消化和吸收,已实现THK的国产化生产,目前,国产化水平已达到80%-90%。工业废处理应用表明,THK是一种简单,节能和高效的气浮设备,非常适合在我国推广应用。 相似文献
189.
Silver-loaded MnO_2 nanomaterials(Ag/MnO_2),including Ag/α-MnO_2,Ag/β-MnO_2,Ag/γ-MnO_2and Ag/δ-MnO_2 nanorods,were prepared with hydrothermal and impregnation methods.The bactericidal activities of four types of Ag/MnO_2 nanomaterials against Escherichia coli were investigated and an inactivation mechanism involving Ag~+ and reactive oxygen species(ROS)was also proposed.The bactericidal activities of Ag/MnO_2 depended on the MnO_2 crystal phase.Among these nanomaterials,Ag/β~-MnO_2 showed the highest bactericidal activity.There was a 6-log decrease in E.coli survival number after treatment with Ag/β~-MnO_2 for120 min.The results of 5,5-dimethyl-l-pyrroline-N-oxide spin-trapping measurements by electron spin resonance indicate OH and O_2~- formation with addition of Ag/β-MnO_2,Ag/γ-MnO_2 or Ag/δ-MnO_2.The strongest peak of OH appeared for Ag/β-MnO_2,while no OH or ·O_2~-signal was found over Ag/α-MnO_2.Through analysis of electron spin resonance(ESR) and Ag+elution results,it could be deduced that the toxicity of Ag~+ eluted from Ag/MnO_2 nanomaterials and ROS played the main roles during the bactericidal process.Silver showed the highest dispersion on the surface of β-MnO_2,which promoted ROS formation and the increase of bactericidal activity.Experimental results also indicated that Ag/MnO_2 induced the production of intracellular ROS and disruption of the cell wall and cell membrane. 相似文献
190.
Lian Gan Yuanyan Xiong Fang Dong Yunjiang Yu Lijuan Zhang E. Shunmei Liliu Zhou Xiaoxia Li Guocheng Hu 《环境科学学报(英文版)》2016,28(6):69-75
Grass carp(Ctenopharyngodon idella) is one of the most important species in China.Decabromodiphenyl ethane(DBDPE) is a brominated flame retardant that has been used widely in industry, and has been observed to accumulate in the tissues of fish from South China. Evidence has shown that DBDPE is toxic to aquatic animals, but the molecular response has been unclear. MicroRNAs(miRNAs) are small noncoding and negative regulatory RNAs that are 20–24 nucleotides in length, which are involved in a wide range of biological processes. We took advantage of deep-sequencing techniques to accurately and comprehensively profile the kidney mi RNA expression of grass carp after 8 weeks of oral exposure to DBDPE. After mapping sequencing data to the genome and Expressed Sequence Tags(ESTs) of grass carp, we identified 493 miRNAs in the sequenced grass carp samples, which included 51 new miRNAs. The results indicated that 5 miRNAs were significantly down-regulated and 36 miRNAs were significantly up-regulated(FDR 0.001,1.5-fold change) after DBDPE exposure. Real-time quantitative PCR(RT-q PCR) was performed on 4 miRNAs from the two samples, and the sequencing and RT-q PCR data were consistent. This study provides the first comprehensive identification of grass carp miRNAs, and the first expression analysis of grass carp miRNAs following DBDPE exposure.The results indicated that miRNAs have potential for use as biomarkers. 相似文献