全文获取类型
收费全文 | 161篇 |
免费 | 10篇 |
国内免费 | 100篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 1篇 |
环保管理 | 35篇 |
综合类 | 116篇 |
基础理论 | 25篇 |
环境理论 | 1篇 |
污染及防治 | 42篇 |
评价与监测 | 2篇 |
社会与环境 | 24篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 15篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 11篇 |
2017年 | 15篇 |
2016年 | 22篇 |
2015年 | 14篇 |
2014年 | 16篇 |
2013年 | 18篇 |
2012年 | 15篇 |
2011年 | 17篇 |
2010年 | 12篇 |
2009年 | 14篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 7篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1972年 | 3篇 |
排序方式: 共有271条查询结果,搜索用时 31 毫秒
91.
农杆菌介导的抗除草剂基因转入两系杂交稻恢复系的研究 总被引:5,自引:0,他引:5
利用农杆菌水稻高效转化系统,成功地将外源BAR基因转入实用性两系要交稻恢复系R187和秀水04,经过除草剂Basta田间涂布试验,其阳性率达到90%以上。对转基因植株同步进行的PCR特异扩增和总DNA Southern检测结果也证实抗Basta的植株中含有BAR基因。讨论了应用转BAR基因的方法提高两系杂交水稻制种纯度的条件。图2表1参3 相似文献
92.
Identification and spatial patterns of coastal water pollution sources based on
GIS and chemometric approach 总被引:1,自引:0,他引:1
Comprehensive and joint applications of GIS and chemometric approach were applied in identification and spatial patterns of coastal water pollution sources with a large data set (5 years (2000-2004), 17 parameters) obtained through coastal water monitoring of Southern Water Control Zone in Hong Kong. According to cluster analysis the pollution degree was significantly different between September-next May (the 1st period) and June-August (the 2nd period). Based on these results, four potential pollution sources, such as organic/eutrophication pollution, natural pollution, mineral/anthropic pollution and fecal pollution were identified by factor analysis/principal component analysis. Then the factor scores of each monitoring site were analyzed using inverse distance weighting method, and the results indicated degree of the influence by various potential pollution sources differed among the monitoring sites. This study indicated that hybrid approach was useful and effective for identification of coastal water pollution source and spatial patterns. 相似文献
93.
Paul Foley 《环境政策》2017,26(5):915-937
To contribute to the literature on transnational sustainability governance hybrids, a new fisheries certification program in Iceland that was originally developed as an alternative to the non-governmental Marine Stewardship Council is examined. While this new program appears on the surface to constitute a purely nationalistic reaction against external non-state authority, the new governance institution is also non-governmental and incorporates international norms and institutions. To explain this new governance hybrid, Robert Cox’s International Political Economy approach to production and power is engaged. This approach theorizes the co-constitution of the social forces of production, state–society complexes and global governance. It is argued that the Icelandic case is not entirely localized or unique; it is part of a broader movement in which social forces of production respond to new market-oriented transnational sustainability governance institutions by developing territorially embedded but transnationally legitimate alternatives. 相似文献
94.
采用过硫酸铵((NH4)2S2O8)-亚硫酸氢钠(NaHSO3)复合引发体系引发丙烯酰胺(AM)单体聚合,合成了一种新型有机-无机杂化絮凝剂聚丙烯酰胺-聚合氯化铝铁(PAM-PAFC)。以产物的特性黏度(η)为依据,逐个探讨了聚合时间、聚合温度、引发剂质量分数和单体质量分数对特性黏度的影响。结果表明,在聚合时间为4 h、聚合温度为50℃、引发剂质量分数为0.5%以及单体质量分数为20%的时候,产物的特性黏度达到最大值513.78 mL·g-1,此条件即为杂化絮凝剂PAM-PAFC的最佳合成条件。电导率分析、红外光谱分析以及差热-热重分析都表明PAM-PAFC链端的-SO42-与带正电荷的羟基铁、羟基铝粒子以离子键的形式相连接。扫描电镜分析表明杂化絮凝剂PAM-PAFC有着明显的空间网状结构。对高岭土-腐殖酸模拟水样的絮凝效果研究表明,达到相同的剩余浊度的条件下,需要投加的杂化絮凝剂PAM-PAFC的量远远低于复配絮凝剂PAM-PAFC。 相似文献
95.
为提高MBR的去除性能并延缓膜污染,采用复合型悬浮生物膜强化膜生物反应器(hybrid suspended biofilm enhanced membrane bioreactor, HSBE-MBR)处理生物制药废水,考察了填料添加方式对HSBE-MBR中典型污染物的去除特征、运行稳定性及膜污染特征的影响,并分析了膜污染机理。结果表明:缺氧区和好氧区添加填料时(工况1),TCOD、${{\rm{NH}}_4^ + }$ -N和TN平均去除率分别为91.61%、97.08%和79.40%;缺氧区、好氧区及膜区添加填料时(工况2),TCOD、${{\rm{NH}}_4^ + }$ -N和TN平均去除率分别为91.09%、97.24%和83.66%。在上述2种工况下,HSBE-MBR对TCOD、${{\rm{NH}}_4^ +} $ -N和TN均具有良好的去除性能,且运行稳定性良好,工况2中TN去除率提高了4.26%。在工况1下,膜运行时间为0.02~8.17 d;在工况2下,膜运行时间为0.26~138 d。2种工况下的膜污染机理均以滤饼层污染为主,滤饼层阻力占比分别为94.7%和90.1%;膜区添加填料能够减缓膜表面滤饼层的形成,使滤饼层阻力降低8.07%;同时,混合液中溶解性微生物代谢产物(soluble microbial products, SMP)、松散结合EPS (loosely bound-EPS, LB-EPS)和紧密结合EPS (tightly bound-EPS, TB-EPS)浓度分别由(63.70±12.95)、(13.97±2.03)和(153.82±12.64) mg·g−1(工况1)降低为(31.77±3.17)、(9.11±0.40)和(78.12±18.92) mg·g−1(工况2)。粒度分布测定结果表明,膜区添加填料后,污泥平均粒径从31.35 μm(工况1)增大至34.71 μm(工况2)。根据污染物去除特征及膜污染特征,确定最优添加方式为在缺氧区、好氧区和膜区添加填料。上述研究结果可为提高MBR运行稳定性并改善膜污染提供参考。 相似文献
96.
Evaluation of factors influencing soluble microbial product in submerged MBR through hybrid ASM model 总被引:1,自引:0,他引:1
Fangyue Li Joachim Behrendt Knut Wichmann Ralf Otterpohl 《Frontiers of Environmental Science & Engineering in China》2009,3(2):226-235
In this study, a mathematical model was established to predict the formation of the soluble microbial product (SMP) in a submerged
membrane bioreactor. The developed model was calibrated under the reference condition. Simulation results were in good agreement
with the measured results under the reference condition. The calibrated model was then used in the scenario studies to evaluate
the effect of three chosen operating parameters: hydraulic retention time (HRT), dissolved oxygen concentration, and sludge
retention time (SRT). Simulation results revealed that the SMP dominated the soluble organic substances in the supernatant.
The scenario studies also revealed that the HRT can be decreased to 1 h without deteriorating the effluent quality; dissolved
oxygen concentration in the reactor can be kept at 2–3 mg/L to maintain the effluent quality, reduce the content of SMP, and
minimize operating costs; the optimal SRT can be controlled to 10–15 d to achieve complete nitrification process, less membrane
fouling potential, and acceptable organic removal efficiency. 相似文献
97.
XU Wenju LI Yuanyou WU Qingyang WANG Shuqi ZHENG Huaiping LIU Wenhua 《环境科学学报(英文版)》2009,21(6):854-857
The effects of phenanthrene (Phe) on hepatosomatic index (HSI) and hepatic enzymatic activities in hybrid tilapia (Oreochromis
niloticus O. aureus ) were investigated via the static freshwater exposure at dosage of 50, 100, and 400 g/L for 4–14 d.
Compared with the control group, HSI was significantly decreased (P < 0.05) at 400 g/L at day 14. Increased enzymatic activities (P
< 0.05) were observed for catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) at either 100 or 400 g/L at
day 8 and 14, as well as for CAT at 50 g/L at day 14, except for GPx at 400 g/L at day 8. Ethoxyresorufin O-deethylase (EROD)
activity was significantly increased (P < 0.05) at all dosage at day 4 as well as at 50 g/L at day 8, but significantly decreased at either
100 or 400 g/L at day 14 (P < 0.05). Glutathione-S-transferase (GST) activity was not a ected. The results suggest that CAT, GPx,
SOD and EROD, as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of
polycyclic aromatic hydrocarbons (PAHs) such as Phe. 相似文献
98.
99.
生物膜复合系统脱氮除磷的特征及微生物群落结构分析 总被引:2,自引:0,他引:2
试验研究了序批式生物膜复合系统在不同有机负荷下氮磷等营养物质的去除特性.结果表明,复合系统在COD负荷为0.35kg.kg-1.d-1(以MLSS计)时能够很好解决脱氮除磷的泥龄矛盾,TP、TN、NH4+-N去除率分别能达到96%、89%和96%,高于对照组的SBR工艺.复合系统中,悬浮污泥对硝化起主要作用,悬浮态污泥和生物膜的硝化平均贡献比为1.66;附着态生物膜对反硝化和除磷起主要作用,生物膜和悬浮态污泥的反硝化贡献比为2.19,释磷贡献比为3.5,摄磷贡献比为3.76.利用PCR-DGGE技术发现,复合系统中存在丰富的脱氮功能菌和除磷功能菌,且悬浮态与附着态微生物的相似性仅为73%,区别较大,说明两者存在一定的分工协作,与反应器的处理特性相一致. 相似文献
100.
《International Journal of Sustainable Engineering》2013,6(2):121-132
Today, energy occupies a pivotal position around which all socio-economic activities revolve. No energy means no life, and supply of energy in a cheap, plentiful, long-sustainable and environmentally safe form is a boon for everyone. In the light of rising cost of oil and fears of its exhaustion coupled with increased pollution, the governments worldwide are deliberating and making huge strides to promote renewable energy sources such as wind. Integration of wind machines with the diesel plants is pursued widely to reduce dependence on fossil-fuel-produced energy and to reduce the release of carbon gases that cause global climate change. The literature indicates that commercial/residential buildings in the Kingdom of Saudi Arabia (KSA) consume an estimated 10–40% of the total electric energy generated. The aim of this study is to analyse wind-speed data of Dhahran (East-Coast, KSA) to assess the economic feasibility of utilising autonomous hybrid wind–diesel power systems to meet the electrical load of 100 typical residential buildings (with annual electrical energy demand of 3512 MWh). The monthly average wind speeds range from 3.3 to 5.6 m/s. The hybrid systems simulated consist of different combinations of 600 kW commercial wind machines supplemented with diesel generators. The National Renewable Energy Laboratory's hybrid optimisation model for electric renewables software was employed to perform the techno-economic analysis. The simulation results indicate that for a hybrid system comprising 600 kW wind capacity together with a 1.0 MW diesel system (two 500 kW units), the wind penetration (at 50 m hub-height, with 0% annual capacity shortage) is 26%. The cost of generating energy (COE, $/kWh) from this hybrid wind–diesel system was found to be 0.070 $/kWh (assuming diesel fuel price of 0.1 $/l). The study exhibits that for a given hybrid configuration, the number of operational hours of diesel generator sets (gensets) decreases with an increase in the wind-farm capacity. Concurrently, emphasis has also been placed on wind penetration, un-met load, effect of hub-height on energy production and COE, excess electricity generation, percentage fuel savings and reduction in carbon emissions (relative to diesel-only situation) of different hybrid systems, cost breakdown of wind–diesel systems, COE of different hybrid systems, etc. 相似文献