全文获取类型
收费全文 | 524篇 |
免费 | 111篇 |
国内免费 | 376篇 |
专业分类
安全科学 | 51篇 |
废物处理 | 153篇 |
环保管理 | 42篇 |
综合类 | 524篇 |
基础理论 | 90篇 |
污染及防治 | 140篇 |
评价与监测 | 3篇 |
社会与环境 | 7篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 10篇 |
2022年 | 23篇 |
2021年 | 38篇 |
2020年 | 36篇 |
2019年 | 31篇 |
2018年 | 41篇 |
2017年 | 36篇 |
2016年 | 44篇 |
2015年 | 55篇 |
2014年 | 66篇 |
2013年 | 65篇 |
2012年 | 68篇 |
2011年 | 41篇 |
2010年 | 29篇 |
2009年 | 38篇 |
2008年 | 28篇 |
2007年 | 40篇 |
2006年 | 47篇 |
2005年 | 43篇 |
2004年 | 33篇 |
2003年 | 27篇 |
2002年 | 25篇 |
2001年 | 24篇 |
2000年 | 18篇 |
1999年 | 23篇 |
1998年 | 20篇 |
1997年 | 7篇 |
1996年 | 13篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有1011条查询结果,搜索用时 93 毫秒
991.
Eiko Obuchi Masaki Suyama Katsuyuki Nakano 《Journal of Material Cycles and Waste Management》2001,3(2):88-92
The catalytic decomposition of mixed plastics consisting of polypropylene (PP) and polyethylene terephthalate (PET) has been
investigated over titania/silica catalysts at 698 K. The yield of oil produced was about 70%, and the large amounts of C18+ hydrocarbons this contained was from the aromatics in PET. Gas was also produced, including C3–C5 hydrocarbons. The carbon-number fractions in the oil was influenced by the PET/(PP + PET) ratios and the catalyst weight.
The titania/silica catalysts could be used repeatedly, and after they had been fouled, could be regenerated. From the Fourier
Transform Infrared (FT–IR) spectroscopic data of adsorbed pyridine on the catalyst surface, most of the acid sites of the
titania/silica catalysts were found to be Lewis sites where the hydride abstracted from PP pyrolysates react with PET pyrolysates
to form oil and gas.
Received: July 19, 2000 / Accepted: October 20, 2000 相似文献
992.
多相光催化水处理技术发展过程中反应器研究的现状及发展趋势 总被引:30,自引:3,他引:27
根据多相光催化反应器的发展历史 ,将多相光催化反应器分为传统的反应器、以机理研究为目的的反应器和以实用化研究为目的的反应器 ,着重介绍了以实用化研究为目的的多相光催化反应器近年来在国内外的研制及应用情况 .阐明了新型多相光催化反应器的研究与设计是光催化氧化法实用化过程中需要解决的关键问题之一 ,论述了目前存在的问题以及今后的发展方向. 相似文献
993.
994.
995.
稀土金属铈对湿式氧化催化剂性能的影响 总被引:15,自引:2,他引:13
采用浸渍沉淀法制备具有相同cu负载量的CuO/7-Al2O3,CuO—CeO2/7-Al2O3和CuO-nO-CeO2/7-Al2O3催化剂,用H酸配水的催化湿式氧化评价催化剂的性能.结果表明,稀土元素Ce作为活性成分,不仅可以显著加快初期的反应速率,而且也增加了第二阶段的反应速率;还能提高反应中间产物小分子羧酸的降解速度和反应终了的pH值,从而减少金属铜的溶出;掺杂Ce使催化剂的晶体大小和孔隙分布更为均匀,孔径增大,有利于催化剂整体性能的改善. 相似文献
996.
A series of Co-Mn mixed oxide catalyst supported on a cordierite monolith was facilely synthesized by ultrasonic impregnation. Its catalytic performance was evaluated in the combustion of toluene, ethyl acetate and its mixture. It was observed that with incorporating Mn into Co3O4, the formation of solid solution with spinel structure could significantly improve the catalytic activity of pure phase Co3O4. And the monolithic Co0.67Mn0.33... 相似文献
997.
Torben Nielsen Anders Feilberg Mona-Lise Binderup 《Environmental science and pollution research international》1999,6(3):133-137
The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen.
In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in
1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for
buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was
caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced
many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH,
while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to
be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator,
was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with
a depletion of benzo(a)pyrene. 相似文献
998.
999.
泡沫镍载二氧化钛光催化降解磺基水杨酸 总被引:12,自引:0,他引:12
为了探索有机物在固定后光催化剂上的降解行为,将TiO2(锐钛型)粉末固定在多孔泡沫镍上,以一只6W主波长为365nm的紫外线杀菌灯为光源,研究了磺基水杨酸(Ssal)在TiO2-Ni体系上的光催化降解。结果表明,Ssal的降解动力学可采用Langmuir-Hinshelwood(L-H)方程来描述。通过测定降解反应的半衰期和测定初始速率的方法确定了L-H方程的参数,两种方法的结果相吻合。还研究了Ssal的光催化降解反应速率与Ph值和温度的关系。结果表明,当Ph值为7.5左右时,Ssal的光催化降解最为有利;当温度从20℃升至50℃时,Ssal的光催化降解加快。通过考察不同Ph值时Ssal在TiO2-Ni体系上的吸附能力探讨了反应初始速率与Ph值的关系 相似文献
1000.