全文获取类型
收费全文 | 168篇 |
免费 | 28篇 |
国内免费 | 81篇 |
专业分类
安全科学 | 23篇 |
废物处理 | 17篇 |
环保管理 | 17篇 |
综合类 | 153篇 |
基础理论 | 25篇 |
污染及防治 | 39篇 |
评价与监测 | 1篇 |
社会与环境 | 1篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 5篇 |
2015年 | 15篇 |
2014年 | 10篇 |
2013年 | 18篇 |
2012年 | 21篇 |
2011年 | 15篇 |
2010年 | 17篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 14篇 |
2006年 | 22篇 |
2005年 | 18篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1990年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有277条查询结果,搜索用时 31 毫秒
71.
采用不同活性恢复手段研究了短期低温(20d,15℃)储存及常温(25℃)低负荷运行后,CANON-MBBR反应器的活性恢复效果.结果显示,CANON悬浮载体经短期低温储存后,通过先恢复温度后缓慢提高进水负荷的方式可使其TN去除负荷恢复率达到102%.若在温度未恢复的基础上直接将进水负荷提升至原水平运行,CANON悬浮载体生物膜将无法维持正常的EPS含量而易发生脱膜现象,致使TN去除负荷恢复率仅为84%.另外,系统有一定基质浓度的基础上,经过25d常温(25℃)低负荷SBR运行后,通过同样的恢复手段可使TN去除负荷恢复率达到96%.通过微生物菌群分析,确定CANON-MBBR系统中功能微生物优势菌属分别为Nitrosomonas和Candidatus Kuenenia,采取合适的恢复手段使系统进入稳定运行阶段后,两者丰度均可分别达到11%以上及27%以上,且悬浮载体脱膜并未对微生物组成造成明显影响. 相似文献
72.
LNG船舶锚泊安全距离定量计算建模 总被引:1,自引:0,他引:1
为保障液化天然气船舶(LNG船舶)锚泊安全,提出了一种基于船舶漂移运动和船舶碰撞风险的锚泊安全距离计算方法.首先,结合船舶运动数学模型,通过蒙特卡洛模拟LNG船舶走锚漂移运动,得出走锚漂移方向概率密度函数,从而确定船舶走锚漂移横向、纵向距离;同时,结合船舶碰撞概率模型、船舶碰撞损害模型和LNG火灾模型,建立LNG船舶碰撞风险模型,确定满足碰撞概率和风险可接受的安全距离.最后,比较两种模型计算结果,并取其较大值作为LNG船舶锚泊安全距离.结果表明,LNG船锚泊安全距离不仅与环境水域的风、流情况有关,还与附近水域内船舶大小及速度有关.建议交通管理中需结合水域环境特征和水域船舶特点确定LNG船舶的锚泊安全距离. 相似文献
73.
Wiszniowski J Surmacz-Górska J Robert D Weber JV 《Journal of environmental management》2007,85(1):59-68
A pre-denitrification activated sludge system (AS) without internal recycle was used in lab-scale studies of landfill leachate treatment. A bentonite supplement at a ratio of 1:4 (mineral : biomass) was used to ensure high sludge settling levels and to serve as a micro-organisms carrier. The system was operated within different parameters such as hydraulic retention time (HRT), ammonia loading rate (ALR) or external recycle ratio, which was adapted to treat varying leachate concentrations of COD and ammonia, ranging from 1020 to 2680 mgO(2)l(-1) and 400-890 mgNH(4)-Nl(-1) respectively. The nitrification was complete and ammonia oxidation reached 99%; this was obtained while the ALR did not exceed 0.09 g NH(4)(+)-Ng(-1)MLVSS d(-1) and HRT was not lower than 1 day (in the aeration reactor). The performance of denitrification was successfully improved by controlling the external recycle rate, when the BOD(5)/N ratio in the raw leachate was 4.1. Consequently, N-removal of up to 80% was achieved. A 10-fold decrease in the denitrification rate was obtained at a BOD(5)/N ratio of 0.5. The efficiency of COD removal varied significantly from 36% to 84%. The positive effect of bentonite addition was determined and is discussed based on preliminary studies. The experiments were carried out in fill-and-draw activated sludge with bentonite; the biomass ratio was 1:2. The activated sludge with bentonite was fed with a synthetic high ammonia and organic-free medium. 相似文献
74.
Nine New Zealand native white-rot fungi were studied for their ability to grow and survive on different substrates formulated from bark, wheat straw, sawdust, apple pomace and maize products in order to identify their pentachlorophenol (PCP) biodegradation potential and to select a fungal carrier for bioaugmentation of polluted soils. Isolates were also evaluated to mineralize (14)C-PCP in liquid culture and in soil. The American fungus Phanerochaete chrysosporium outgrew the native fungi on the substrates tested, but the high colonisation did not result in superior PCP dechlorination as measured by chloride release. Whilst Trametes versicolor inocula produced on wheat straw and SCS (sawdust-corn meal-starch-mix) gave the highest chloride release, colonization of these two substrates as measured by biological potential was lower compared to the pomace and pomace-sawdust-mix. Neither lignin peroxidase nor manganese peroxidase production were measured for New Zealand white-rot fungi during the experiments. Laccase was the only enzyme detected. In liquid culture, the mineralisation rate was higher for T. versicolor isolates compared to P. chyrysoporium. Very little to no pentachloroanisole (PCA) was captured in the volatile fraction of T. versicolor isolates, whereas 75% of the volatile fraction of P. chrysosporium consisted of PCA. The soil microcosms studies, using contaminated soil from a timber treatment site, clearly showed that the New Zealand T. versicolor isolates mineralized PCP. Degradation of PCP in non-sterile soil was higher in the presence of white-rot fungi than in soil without white-rot fungus. This demonstrates that viable white-rot fungus is necessary for significant PCP degradation and that T. versicolor isolates showed PCP remediation potential. Wheat straw and SCS could be suitable carriers for New Zealand native T. versicolor isolates for bioremediation of PCP polluted soil sites. 相似文献
75.
76.
77.
孙杰 《中国环境管理干部学院学报》2005,15(1):102-104
档案是自然、社会和人类思维活动的真实反映.它作为一种载体,记录着人类的历史、文明、发展和智慧,是衡量一个国家文明程度的标尺,是人类进步的基础,是知识和信息的汇集. 相似文献
78.
颗粒活性炭载体新型生物转盘去除生活污水中COD和NH3-N的研究 总被引:2,自引:0,他引:2
开发一种改进型生物转盘处理生活污水,将盘片改为转笼状,并向其中加入颗粒活性发作为载体,研究该系统对生活污水的处理效果。结果表明:在转盘转速为15rpm和HRT分别为10h、8h、6h、4.5h情况下,进水COD平均浓度约为223mg/L,出水COD平均浓度分别为15.6、17.9、23.4、28.2mg/L,平均去除率为93.0%、91.9%、89.5%、86.6%;进水NH3-N平均浓度约为22mg/L,出水NH3-N平均浓度分别为0.32、1.13、2.30、5.71mg/L,平均去除率为98.5%、94.8%、89.7%、74.6%。 相似文献
79.
80.