全文获取类型
收费全文 | 2302篇 |
免费 | 201篇 |
国内免费 | 322篇 |
专业分类
安全科学 | 326篇 |
废物处理 | 147篇 |
环保管理 | 474篇 |
综合类 | 1182篇 |
基础理论 | 253篇 |
环境理论 | 4篇 |
污染及防治 | 212篇 |
评价与监测 | 73篇 |
社会与环境 | 134篇 |
灾害及防治 | 20篇 |
出版年
2024年 | 2篇 |
2023年 | 28篇 |
2022年 | 30篇 |
2021年 | 51篇 |
2020年 | 75篇 |
2019年 | 72篇 |
2018年 | 48篇 |
2017年 | 78篇 |
2016年 | 96篇 |
2015年 | 82篇 |
2014年 | 97篇 |
2013年 | 187篇 |
2012年 | 197篇 |
2011年 | 195篇 |
2010年 | 130篇 |
2009年 | 161篇 |
2008年 | 98篇 |
2007年 | 144篇 |
2006年 | 130篇 |
2005年 | 110篇 |
2004年 | 103篇 |
2003年 | 111篇 |
2002年 | 114篇 |
2001年 | 80篇 |
2000年 | 77篇 |
1999年 | 62篇 |
1998年 | 52篇 |
1997年 | 65篇 |
1996年 | 40篇 |
1995年 | 34篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有2825条查询结果,搜索用时 281 毫秒
991.
This study attempts to use plentiful available high oil content (67% of Nahar seed kernel) non-edible feedstock as a source for powering diesel engine. Various performance and emission characteristics of prepared Nahar oil–diesel blends (5%, 10%, 20%, 30%, and 40%) are analyzed in a single cylinder direct injection diesel engine at different load spectrum, in order to judge the optimum blend, which can be efficiently used in a diesel engine. 10% blending of Nahar oil with diesel fuel has shown a reduction in hydrocarbon and carbon monoxide emission by 8.64% and 8.34%, respectively. With the increase in blend concentration, the nitrogen oxide emission decreased considerably and smoke emission increased slightly. Further pressure crank angle and heat release rate analysis of 10% blending of Nahar oil with diesel confirms its smooth combustion inside the engine combustion chamber. 相似文献
992.
Taiping Xie Longjun Xu Chenglun Liu Zhiming Bi 《International Journal of Green Energy》2018,15(10):545-549
Fuel ethanol was produced using rice straw with the simultaneous saccharification and fermentation (SSF) method. The influence of cellulose liquefaction pretreatment and Fe2+ quantity on ethanol productivity was investigated in detail. At the same time, the optimized conditions including fermentation temperature, Fe2+ amount, yeast inoculation quantity, and the inoculated cellulose enzyme dosage in the SSF process were systematically investigated by analyzing fuel ethanol yield. The result indicated that fuel ethanol yield was 0.319 g per gram rice straw by SSF approach when appropriate amount of Fe2+ was added into the reaction system. The optimal technology parameters were: fermenting temperature of 36°C, Fe2+ amount of 4 mg · g?1, inoculating proportion of 20%, cellulose enzyme of 20 IU · g?1, and Pachysolen tannophilu/saecharomyces cerevisiae of 1:2 ratio. The ethanol yield under the best conditions was larger than that of the control group. We hope that this research can facilitate to achieve large-scale comprehensive utilization for rice straw. 相似文献
993.
This paper examines local government and non‐governmental organisation (NGO) engagement in disaster response in the wake of the M/T Solar 1 oil spill in Guimaras, Western Visayas, Philippines, on 11 August 2006. It assesses the response activities of these two entities as well as the institutional factors that affected their interaction on the ground. Local government and NGO engagement was shaped by multi‐layered, overlapping, and oftentimes contending government‐designed response frameworks. Within these frameworks, government actors played the role of primary implementer and provider of relief, allowing them to determine who could be involved and the extent of their involvement. The absence of formal roles for NGOs in these frameworks not only undermines their ability to work in a setting where such institutional set‐ups are operational but also it reaffirms their ‘outsider’ status. This study of the Guimaras oil spill illustrates the complexity and the institutional difficulties inherent in disaster response and coordination in the Philippines. 相似文献
994.
995.
996.
高效物化法处理炼油废水 总被引:6,自引:0,他引:6
采用斜板式隔油沉淀与两级混凝气浮组成的工艺处理炼油废水。隔油池中设置斜板提高了油与悬浮物的去除率,同时也提高了油的回收量。循环式刮油刮泥机可及时刮除浮油与沉泥。混凝使胶粒与乳化油粒脱稳、聚集,易被气浮法去除。两级气浮串联使气浮系统的去除效率高并运行稳定。 相似文献
997.
998.
稠油及超稠油污水具有黏度大、油水密度差小、乳化严重、水温高、水质水量变化大、成分复杂等特点,该废水的B/C小于0.3,属于难生物降解污水.通过试验表明,采用预处理工艺先除油、除悬浮物,再进行生物处理工艺去除可生化降解COD,最后经过深度处理工艺去除残余的难生化降解COD,可保证处理后水质全面达标. 相似文献
999.
1000.