全文获取类型
收费全文 | 299篇 |
免费 | 31篇 |
国内免费 | 106篇 |
专业分类
安全科学 | 43篇 |
废物处理 | 20篇 |
环保管理 | 30篇 |
综合类 | 227篇 |
基础理论 | 42篇 |
污染及防治 | 65篇 |
评价与监测 | 4篇 |
社会与环境 | 2篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 13篇 |
2021年 | 11篇 |
2020年 | 19篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 13篇 |
2016年 | 8篇 |
2015年 | 17篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 29篇 |
2011年 | 20篇 |
2010年 | 21篇 |
2009年 | 15篇 |
2008年 | 19篇 |
2007年 | 20篇 |
2006年 | 32篇 |
2005年 | 24篇 |
2004年 | 15篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有436条查询结果,搜索用时 328 毫秒
1.
亲水性多孔载体在流化床中的生物膜形成过程分析 总被引:2,自引:0,他引:2
采用实验制备的一种新型亲水性多孔聚合物作为流化床反应器中生物膜附着生长的载体,实现流态化水力条件下的生物挂膜过程.在3个结构尺寸相同的流化床反应器中考察了接种污泥浓度、进水有机负荷及载体粒径对亲水性多孔载体生物挂膜量的影响,试验结果表明,接种污泥浓度为30 g VSS/L、进水TOC值为350 mg/L、载体粒径为5~8 mm时载体表面的附着生物量最大,反应器运行12 d的载体附着生物量达到4.45 g VSS/L,膜结构稳定,表现出较活性污泥法更高的活性.在进水TOC、氨氮浓度分别为350 ms/L、50 mg/L,HRT为6 h的情况下,两者的去除率分别达到了97.1%和64.3%,表明载体上的生物膜对污水中TOC及氨氮的去除表现出高效率.挂膜后载体表面上的微生物以丝状菌为主,孔壁上的微生物以球菌和杆菌为主要生物相,证明载体内外表面皆适宜微生物的生长,并且形成合理的生物相分布. 相似文献
2.
An assessment of the pollution status of River Illo, located within River Owo catchments area in Ota, Ogun State, Nigeria,
was carried out. The River’s response to deoxygenation due to BOD loading from an abattoir and its dissolved oxygen (DO) level
was predicted using the modified Streeter-Phelps model. The average concentrations of measured parameters at the sampling
stations include: 2.24 mg/l of DO, 312.85 mg/l of BOD, 782.86 mg/l of chemical oxygen demand, and 620.76 g/l of total solids.
The DO model for River Illo showed a positive correlation between measured and calculated DO, while the dissolved oxygen curve
gave a double spoon shape of two major segments with distinct zones of degradation, decomposition, and recovery. The self-purification
factor (f) for both segments ranged between 0.8 and 1.1 depicting River Illo as a slow moving or sluggish river. The above results
revealed slow reaeration of the water body while full recovery from pollution was difficult. The treatment of River Illo before
usage is very essential to ensure public health safety of users from waterborne diseases. 相似文献
3.
The performance of Ce-OMS-2 catalysts was improved by tuning the fill percentage in the hydrothermal synthesis process to increase the oxygen vacancy density. The Ce-OMS-2 samples were prepared with different fill percentages by means of a hydrothermal approach (i.e. 80%, 70%, 50% and 30%). Ce-OMS-2 with 80% fill percentage (Ce-OMS-2-80%) showed ozone conversion of 97%, and a lifetime experiment carried out for more than 20?days showed that the activity of the catalyst still remained satisfactorily high (91%). For Ce-OMS-2-80%, Mn ions in the framework as well as K ions in the tunnel sites were replaced by Ce4+, while for the others only Mn ions were replaced. O2-TPD and H2-TPR measurements proved that the Ce-OMS-2-80% catalyst possessed the greatest number of mobile surface oxygen species. XPS and XAFS showed that increasing the fill percentage can reduce the AOS of Mn and augment the amount of oxygen vacancies. The active sites, which accelerate the elimination of O3, can be enriched by increasing the oxygen vacancies. These findings indicate that increasing ozone removal can be achieved by tuning the fill percentage in the hydrothermal synthesis process. 相似文献
4.
5.
用微生物传感器快速法和稀释接种法对地表水和污水处理厂出水中的生化需氧量(BOD)进行了测定,用数理统计的方法对两种方法测定的结果进行了比较。 相似文献
6.
生物膜反应器处理洗涤污水的试验 总被引:1,自引:0,他引:1
介绍了采用生物膜反应器处理洗涤污水的试验研究方法,研究了COD、LAS和NH3-N的去除效果。试验结果表明:整个系统出水稳定,水质良好(COD〈38.7mg/L、NH3-N〈1.1mg/L、LAS〈0.9mg/L,且无色无味、无SS),符合国家建设部生活杂用水回用水质标准,且具有较强的抗冲击负荷能力。在生物膜反应器中,微生物对污染物的去除起主要作用,而中空纤维膜对维持系统的稳定出水起重要作用。 相似文献
7.
D. J. H. Brock 《黑龙江环境通报》1994,14(13):1243-1252
A number of different models of CF carrier screening have now been tested in pilot trials. Apart from opportunistic and cascade testing (which are strictly speaking not true forms of screening), the major programmes have been directed either to young adults in primary care or to pregnant women in antenatal clinics. Only in the latter form of screening has sufficient data been collected to allow conclusions to be reached on the optimum mode of delivery. It seems very probable that when CF carrier screening passes into routine service, it will be the antenatal couple model that is used. 相似文献
8.
9.
水中化学耗氧量的快速测定法 总被引:3,自引:0,他引:3
利用烘箱法测定水中的化学耗氧量是国内外在微量分析测定方法上较为先进的分析,优点是仪器、设备简便、操作简单、分析快速、节省大量化学试剂,可以大批量地进行试验.实验中不加入硫酸汞试剂,避免或减少了汞污染.方法的空白值较好,提高了实验的精密度和准确度,是一种易推广的方法 相似文献
10.