全文获取类型
收费全文 | 1102篇 |
免费 | 123篇 |
国内免费 | 858篇 |
专业分类
安全科学 | 68篇 |
废物处理 | 115篇 |
环保管理 | 97篇 |
综合类 | 1119篇 |
基础理论 | 171篇 |
污染及防治 | 483篇 |
评价与监测 | 25篇 |
社会与环境 | 2篇 |
灾害及防治 | 3篇 |
出版年
2024年 | 5篇 |
2023年 | 30篇 |
2022年 | 46篇 |
2021年 | 46篇 |
2020年 | 59篇 |
2019年 | 77篇 |
2018年 | 58篇 |
2017年 | 63篇 |
2016年 | 85篇 |
2015年 | 108篇 |
2014年 | 110篇 |
2013年 | 106篇 |
2012年 | 134篇 |
2011年 | 110篇 |
2010年 | 99篇 |
2009年 | 121篇 |
2008年 | 81篇 |
2007年 | 146篇 |
2006年 | 128篇 |
2005年 | 93篇 |
2004年 | 63篇 |
2003年 | 55篇 |
2002年 | 52篇 |
2001年 | 44篇 |
2000年 | 30篇 |
1999年 | 24篇 |
1998年 | 33篇 |
1997年 | 23篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 18篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有2083条查询结果,搜索用时 15 毫秒
161.
The environmental impact of nanotechnology has caused a great concern. Many in vitro studies showed that many types of nanoparticles were cytotoxic. However, whether these nanoparticles caused cell membrane damage was not well studied. F2-isoprostanes are specific products of arachidonic acid peroxidation by nonenzymatic reactive oxygen species and are considered as reliable biomarkers of oxidative stress and lipid peroxidation. In this article, we investigated the cytotoxicity of different nanoparticles and the degree of cellular membrane damage by using F2-isoprostanes as biomarkers after exposure to nanoparticles. The human lung epithelial cell line A549 was exposed to four silica and metal oxide nanoparticles: SiO2 (15 nm), CeO2 (20 nm), Fe2O3 (30 nm), and ZnO (70 nm). The levels of F2-isoprostanes were determined by using high-performance liquid chromatography/mass spectrometry. The F2-isoprostanes’ peak was identified by retention time and molecular ion m/z at 353. Oasis HLB cartridge was used to extract F2-isoprostanes from cell medium. The results showed that SiO2, CeO2, and ZnO nanoparticles increased F2-isoprostanes levels significantly in A549 cells. Fe2O3 nanoparticle also increased F2-isoprostanes level, but was not significant. This implied that SiO2, CeO2, ZnO, and Fe2O3 nanoparticles can cause cell membrane damage due to the lipid peroxidation. To the best of our knowledge, this is the first report on the investigation of effects of cellular exposure to metal oxide and silica nanoparticles on the cellular F2-isoprostanes levels. 相似文献
162.
冯欣 《环境保护与循环经济》2021,41(2):34-36
农村污水治理是改善农村人居环境的重要内容之一,介绍了3种适用于农村水质敏感地区的污水处理技术:间歇曝气活性污泥法、生态处理技术、膜生物法,并对3种污水处理技术的优缺点进行了比较分析. 相似文献
163.
164.
对失去大部分活性的微生物膜进行再培养,以研究膜再利用的可能性。试验结果初部表明:在1/2MS培养基中加入一定量的植物激素,不仅可以使膜的电位值(I0)显著升高,且活性强,稳定性好,可使膜重复利用。 相似文献
165.
研究了以三辛胺(TOA)为流动载体的乳状液膜法提取对H酸的最优膜配方及工艺条件,并以实际工业废水进行验证。考察了膜相表面活性剂浓度、载体浓度、外水相pH值、乳水比、内水相浓度对水中COD值去除的影响。通过正交试验,结果表明:以质量分数为3%的聚胺型表面活性剂,体积分数为4%的TOA,质量分数10%的内水相NaOH溶液,油内比Roi为2∶1的乳状液膜体系,处理初始浓度为50 000 mg/L H酸废水,在pH值为3,乳水比Rew为1∶5的传质条件下,对含H酸废水的COD去除率可达90%以上。 相似文献
166.
167.
Liquid water management is still a critical issue in the improvement of proton exchange membrane fuel cell (PEMFC) performance. In this work, for the first time, the liquid water behavior and transport inside the cathode of a PEMFC with a stirred tank reactor (STR) design, rather than the conventional PEMFC flow channel design, are numerically studied. The dynamic contact angle (DCA) is applied to multiple wall boundaries in the numerical model through a user-defined-function (UDF) code, i.e., STR-DCA model. Another numerical model with the static contact angle (SCA) and same operating conditions, i.e., STR-SCA model, is also developed for comparison. The volume of fluid (VOF) method is employed in the simulation to track the gas-liquid interface. The results show that the liquid water distribution and transport are significantly different between these two models, indicating the remarkable effects of DCA on the simulation results. It is also verified the capability of STR-PEMFC to reduce the liquid water flooding, showing the potential of this channel-less type fuel cell in the further development. 相似文献
168.
Francisco M. Baena-Moreno Mónica Rodríguez-Galán Fernando Vega Luis F. Vilches Benito Navarrete 《International Journal of Green Energy》2019,16(5):401-412
Biomethane production through biogas upgrading is a promising renewable energy for some industries which could be part of the equilibrium needed with fossil fuels consumption to achieve a sustainable society. This paper presents a comprehensive list of biogas upgrading technologies focused on carbon dioxide removal as well as recent advances reported by researcher with wide expertise in this topic. Additionally, an extensive costs–performance comparison among the technologies studied is discussed. Among the different alternatives, chemical scrubbing stood out to achieve high biomethane purities while cryogenic technologies proved to be effective against methane losses. Regarding the different costs, water scrubbing and membrane separation seem to be the most affordable techniques. 相似文献
169.
A novel method was developed to suppress membrane fouling in submerged membrane bioreactors. The method is based on the dielectrophoretic (DEP) motion of particles in an inhomogeneous electrical field. Using a real sample of biomass as feed, the fouling-suppression performance using DEP with different electrical field intensities (60–160 V) and different frequencies (50–1000 Hz) was investigated. The fouling-suppression performance was found to relate closely with the intensity and frequency of the electrical field. A stronger electrical field was found to better recover the filtrate flux. This is because of a stronger DEP force acting on the biomass particles close to the membrane's surface. Above an intensity and frequency value of 130 V and 1 kHz, respectively the permeate flux was reduced due to an electrothermal effect. 相似文献
170.
采用液膜萃取—酸析沉降—络合萃取组合工艺对有机磷阻燃剂生产废水进行预处理.最佳工艺条件为:液膜萃取时,液膜油相(表面活性剂与煤油的混合液)与内水相(H2SO4溶液)的体积比2∶1、乳化液膜与废水的体积比1∶8、废水pH 13.0,硫酸体积分数10%、煤油中表面活性剂质量浓度30 g/L、液膜萃取时间 15 min;酸析沉降时,废水pH l.0,酸析沉降时间30 min;络合萃取时,络合萃取剂(烷基叔胺N235与煤油的混合液)中烷基叔胺N235体积分数30%,络合萃取剂与废水的体积比1∶4,废水pH l.0,络合萃取时间30 min.在此最佳处理条件下,废水COD总去除率可达93%,吡啶去除率达99.9%以上,总磷去除率可达97%,BOD5/COD提高至0.32,有利于后续生化处理. 相似文献