全文获取类型
收费全文 | 1072篇 |
免费 | 125篇 |
国内免费 | 700篇 |
专业分类
安全科学 | 68篇 |
废物处理 | 112篇 |
环保管理 | 98篇 |
综合类 | 1090篇 |
基础理论 | 171篇 |
污染及防治 | 326篇 |
评价与监测 | 27篇 |
社会与环境 | 2篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 11篇 |
2022年 | 25篇 |
2021年 | 27篇 |
2020年 | 44篇 |
2019年 | 57篇 |
2018年 | 47篇 |
2017年 | 45篇 |
2016年 | 59篇 |
2015年 | 96篇 |
2014年 | 104篇 |
2013年 | 104篇 |
2012年 | 132篇 |
2011年 | 111篇 |
2010年 | 100篇 |
2009年 | 118篇 |
2008年 | 75篇 |
2007年 | 145篇 |
2006年 | 125篇 |
2005年 | 95篇 |
2004年 | 64篇 |
2003年 | 56篇 |
2002年 | 52篇 |
2001年 | 43篇 |
2000年 | 30篇 |
1999年 | 22篇 |
1998年 | 33篇 |
1997年 | 22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 |
1972年 | 1篇 |
排序方式: 共有1897条查询结果,搜索用时 951 毫秒
251.
252.
253.
Bacterial diversity in activated sludge from a consecutively aerated submerged
membrane bioreactor treating domestic wastewater 总被引:1,自引:0,他引:1
DU Cheng WU Zhenbin XIAO Enrong ZHOU Qiaohong CHENG Shuiping LIANG Wei HE Feng 《环境科学学报(英文版)》2008,20(10):1210-1217
The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?l... 相似文献
254.
Bioaugmentation with genetically engineered microorganisms (GEMs) in a membrane bioreactor (MBR) for enhanced removal of recalcitrant
pollutants was explored. An atrazine-degrading genetically engineered microorganism (GEM) with green fluorescent protein was
inoculated into an MBR and the effects of such a bioaugmentation strategy on atrazine removal were investigated. The results
show that atrazine removal was improved greatly in the bioaugmented MBR compared with a control system. After a start-up period
of 6 days, average 94.7% of atrazine was removed in bioaugmented MBR when atrazine concentration of influent was 14.5 mg/L.
The volumetric removal rates increased linearly followed by atrazine loading increase and the maximum was 65.5 mg/(L·d). No
negative effects were found on COD removal although carbon oxidation activity of bioaugmented sludge was lower than that of
common sludge. After inoculation, adsorption to sludge flocs was favorable for GEM survival. The GEM population size initially
decreased shortly and then was kept constant at about 104–105 CFU/mL. Predation of micro-organisms played an important role in the decay of the GEM population. GEM leakage from MBR was
less than 102 CFU/mL initially and was then undetectable. In contrast, in a conventionally activated sludge bioreactor (CAS), sludge bulking
occurred possibly due to atrazine exposure, resulting in bioaugmentation failure and serious GEM leakage. So MBR was superior
to CAS in atrazine bioaugmentation treatment using GEM. 相似文献
255.
Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH3 in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors. 相似文献
256.
257.
258.
采用重量法用滤筒替代滤膜进行测定水中悬浮物的比对实验,实验结果表明:滤筒测定水中悬浮物比滤膜测定水中悬浮物更具有易恒重、测定误差小、准确度高、快速、简便、成本低等优点,适合水质监测应用。 相似文献
259.
射流曝气MBR处理啤酒废水的试验 总被引:1,自引:0,他引:1
射流曝气提高了系统的氧利用效率及传质效率.通过逐渐提高进水的容积负荷来考察系统的处理效果, 试验表明, 利用射流曝气MBR处理模拟啤酒废水是可行的, 系统对COD、氨氮、浊度平均去除率为95.74%,97.84%,99.5%.由于系统运行期间不排泥, 因此系统对P O43-的去除效果不佳, 平均去除率为42.9%.膜对... 相似文献
260.
近年来,水资源短缺,水源污染严重,国家对水处理末端的资源化利用提出了更高的要求,分盐过程也受到越来越多的关注.纳滤膜表面通常带有电荷,可以选择性地透过不同价态的离子.基于纳滤膜表面电荷特性不同,为很好地实现盐的分离,将制备的带有磺酸基团的氧化石墨烯引入到纳滤膜材料中,采用界面聚合法,制备了SGO改性复合纳滤膜. Zeta电位分析表明所制备的复合纳滤膜表面的电荷比不添加SGO的纳滤膜更负;红外光谱分析中酯基基团特征峰的出现表明磺酸基团参与了聚合反应; SEM结构表面,膜表面出现了明显的图灵结构,在0. 2 MPa压力下,纯水通量可达45. 85 L·(m~2·h)-1,对Na2SO4截留率为98. 23%,对Na Cl截留率为24. 93%,10 h运行可以很好地实现对SO_4~(2-)、Cl~-的有效分离,可实现盐的资源化回收. 相似文献