全文获取类型
收费全文 | 787篇 |
免费 | 99篇 |
国内免费 | 377篇 |
专业分类
安全科学 | 102篇 |
废物处理 | 46篇 |
环保管理 | 143篇 |
综合类 | 633篇 |
基础理论 | 151篇 |
环境理论 | 1篇 |
污染及防治 | 120篇 |
评价与监测 | 24篇 |
社会与环境 | 31篇 |
灾害及防治 | 12篇 |
出版年
2024年 | 4篇 |
2023年 | 10篇 |
2022年 | 26篇 |
2021年 | 33篇 |
2020年 | 36篇 |
2019年 | 42篇 |
2018年 | 50篇 |
2017年 | 56篇 |
2016年 | 65篇 |
2015年 | 59篇 |
2014年 | 82篇 |
2013年 | 89篇 |
2012年 | 90篇 |
2011年 | 82篇 |
2010年 | 68篇 |
2009年 | 62篇 |
2008年 | 50篇 |
2007年 | 51篇 |
2006年 | 64篇 |
2005年 | 43篇 |
2004年 | 25篇 |
2003年 | 35篇 |
2002年 | 18篇 |
2001年 | 19篇 |
2000年 | 17篇 |
1999年 | 17篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1996年 | 13篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有1263条查询结果,搜索用时 849 毫秒
381.
Carmen Difiglio Dolf Gielen 《Mitigation and Adaptation Strategies for Global Change》2007,12(3):387-405
If hydrogen (H2) is to significantly reduce greenhouse gas emissions and oil use, it needs to displace conventional transport fuels and be
produced in ways that do not generate significant greenhouse gas emissions. This paper analyses alternative ways H2 can be produced, transported and used to achieve these goals. Several H2 scenarios are developed and compared to each other. In addition, other technology options to achieve these goals are analyzed.
A full fuel cycle analysis is used to compare the energy use and carbon (C) emissions of different fuel and vehicle strategies.
Fuel and vehicle costs are presented as well as cost-effectiveness estimates. Lowest hydrogen fuel costs are achieved using
fossil fuels with carbon capture and storage. The fuel supply cost for a H2 fuel cell car would be close to those for an advanced gasoline car, once a large-scale supply system has been established.
Biomass, wind, nuclear and solar sources are estimated to be considerably more expensive. However fuel cells cost much more
than combustion engines. When vehicle costs are considered, climate policy incentives are probably insufficient to achieve
a switch to H2. The carbon dioxide (CO2) mitigation cost would amount to several hundred US$ per ton of CO2. Energy security goals and the eventual need to stabilize greenhouse gas concentrations could be sufficient. Nonetheless,
substantial development of related technologies, such as C capture and storage will be needed. Significant H2 use will also require substantial market intervention during a transition period when there are too few vehicles to motivate
widely available H2 refueling.
相似文献
Dolf GielenEmail: |
382.
383.
对两个城市的小型垃圾转运站现状进行了分析,并对其渗滤液产生量及渗滤液性质进行了监测。结果表明:小型垃圾转运站转运量小、分布密集;深圳垃圾转运站产生的混合污水并入城市污水管网,常州的小型垃圾转运站,产生的渗滤液及冲洗废水50%直接排入了河道;转运站排放的混合污水,除汞外,其他指标远超GB 8978-1996《污水综合排放标准》及CJ 3082-1999《污水排入城市下水道水质标准》,小型垃圾转运站排放的污染物中,以COD负荷最高,其次是BOD5。大量的有机物排入城市污水厂,对污水厂的正常运行造成冲击,如果直接排入水体,更加速了水体的污染,因此,常州市城市排水系统优化改造及垃圾转运站的截污、治理势在必行。 相似文献
384.
湖南某地采铀试验工程废水处理工艺设计 总被引:1,自引:0,他引:1
通过分析湖南境内某铀矿原地爆破浸出、地表堆浸采铀试验工程工艺流程以及该工程产生的废水源强及性质,介绍了BaCl2-Ca(OH)2中和沉淀法对该股废水处理的可行性及达到的效果。 相似文献
385.
Potassium-modified ceria-zirconia catalyst was synthesized by wetness impregnation method.The ageing treatment was performed in static air at 800°C for 20 hr to evaluate the thermal stability of the catalyst.The catalysts were characterized by X-ray diffraction,BET surface area,oxygen storage capacity,NOx-temperature programmed desorption and soot-temperature programmed oxidation measurements.By introduction of potassium,the maximum soot oxidation rate temperature(Tm) of the ceria-zirconia based catalyst de... 相似文献
386.
387.
388.
PAC强化“水解酸化+CAST”工艺处理混合化工废水的研究 总被引:1,自引:0,他引:1
采用粉末活性炭(PAC)强化"水解酸化+CAST"工艺对混合化工废水进行研究。试验结果表明:PAC强化"水解酸化+CAST"工艺对进水中COD、难降解COD、BOD5、NH3-N和TP等参数的去除率分别达到了82.8%、52.8%、95.8%、88.8%和94.2%,实际出水水质有了很明显提高。PAC与活性污泥法耦合处理废水,PAC在产生吸附作用的同时,具有与生物协同的降解作用。通过改变PAC的投加方式和投加量试验,出于经济方面考虑,在保证出水水质指标达标的前提下,确定2~3天为一个比较合理的PAC投加周期。 相似文献
389.
Yamei Dong Zhenjia Zhang Yongwei Jin Jian Lu Xuehang Cheng Jun Li Yan-yan Deng Ya-nan Feng Dongning Chen 《环境科学学报(英文版)》2012,24(6):999-1005
A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater (ethanol fuel production) treatment has been designed. The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane (WPU) gel carrier were evaluated after acclimation. In the acclimation period, nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction (PCR) was also carried out to investigate the change in ammonium-oxidizing bacteria. The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/(L-pellet. hr) and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation. A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15% (V/V). Under the conditions of 75 mg/L influent ammonia, hydraulic retention time (HRT) of 3.7--5.6 hr, and dissolved oxygen (DO) of 4 mg/L, the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90%. While the highest ammonia removal rate, 162 mg-N/(L-pellet.hr), was observed when the HRT was 1.3 hr. 相似文献
390.
本菲尔溶液在工业脱除二氧化碳中已获得较广泛的应用,但存在吸收速率差、再生负荷高等缺点。开发新型复合溶液成为目前研究热点。采用搅拌实验装置,研究不同配比的碳酸钾-TETA复合溶液对烟道气中二氧化碳的吸收和解吸性能,揭示了吸收速率、吸收容量与酸碱度、时间之间的内在联系,并对CO2从复合溶液中初始逸出温度、溶液再生温度、溶液再生率、再生前后溶液pH下降率进行了细致记录分析。实验结果表明:碳酸钾-TETA复合溶液配比为0.6∶0.4时吸收效果最佳,吸收量约为0.914mol/L;同时再生温度最低,为106℃;再生率最高,为96.7%。与相同配比的碳酸钾-MEA(一乙醇胺)、碳酸钾-DEA(二乙醇胺)、碳酸钾-DETA(二乙烯三胺)复合溶液相比具有一定再生优势。实验结果还表明碳酸钾-TETA复合体系之间存在正交互作用。 相似文献