全文获取类型
收费全文 | 1249篇 |
免费 | 25篇 |
国内免费 | 130篇 |
专业分类
安全科学 | 57篇 |
废物处理 | 77篇 |
环保管理 | 123篇 |
综合类 | 258篇 |
基础理论 | 260篇 |
环境理论 | 2篇 |
污染及防治 | 452篇 |
评价与监测 | 94篇 |
社会与环境 | 63篇 |
灾害及防治 | 18篇 |
出版年
2023年 | 13篇 |
2022年 | 58篇 |
2021年 | 37篇 |
2020年 | 20篇 |
2019年 | 33篇 |
2018年 | 39篇 |
2017年 | 47篇 |
2016年 | 60篇 |
2015年 | 51篇 |
2014年 | 82篇 |
2013年 | 111篇 |
2012年 | 85篇 |
2011年 | 116篇 |
2010年 | 75篇 |
2009年 | 57篇 |
2008年 | 73篇 |
2007年 | 92篇 |
2006年 | 82篇 |
2005年 | 35篇 |
2004年 | 36篇 |
2003年 | 33篇 |
2002年 | 37篇 |
2001年 | 22篇 |
2000年 | 17篇 |
1999年 | 18篇 |
1998年 | 6篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有1404条查询结果,搜索用时 31 毫秒
141.
142.
The treatment of chromium-containing leather waste (CCLW), the major solid waste generated at the post-tanning operations of leather processing, has the potential to generate value-added leather chemicals. Various alkali and enzymatic hydrolysis were compared, and calcium oxide was found to be important for effective (but still incomplete) hydrolysis. Three possible reasons are given for the incomplete hydrolysis under alkaline conditions. Data for 19 amino acids are presented for four different treatment products. On the basis of the results, a novel three-step CCLW treatment process is proposed. The gelatin extracted in the first step is chemically modified to produce leather finishing agents. The collagen hydrolysates isolated in the second step are used as proteinic retanning agents by chemical modification. The remaining chrome cake is further hydrolyzed with acids in the third step, and the obtained chromium-containing protein hydrolysates could be used for the preparation of chromium-containing retanning agents for leather industry. The proposed three-step process provides a feasible zero discharge process for the treatment of CCLW. 相似文献
143.
Inertization of pyrite cinders and co-inertization with electric arc furnace flue dusts by pyroconsolidation at solid state 总被引:2,自引:0,他引:2
The viability of a pyroconsolidation process to render pyrite cinders inert and to co-inert pyrite cinders with a hazardous polymetallic residue such as electric arc furnace flue dusts (EAF) containing Pb, Cu, Zn, As, Cr, Ni and Mo were investigated. The effects of pyroconsolidation temperature (800-1200 degrees C), milling pyrite cinders and additions of both CaO and EAF on the resulting microstructure of the pellets were determined. The microstructural changes were then compared with the results of the standard leaching tests. Full inertization of pyrite cinders was achieved after milling to < 100 micron followed by a pelletization and pyroconsolidation process at a temperature of 1200 degrees C. This process also allows co-inertization of pyrite cinders with controlled additions of EAF (up to approximately to 10%). Following pyroconsolidation at 1200 degrees C, the metallic elements were inert components in the four main phases: traces of Cr in hematite; Cr, Cu, Zn and Ni in spinel-phase; traces of Cr and Zn in calcium ferrites; and Pb and traces of Cu, Zn and Ba in K-Ca-Al-Fe glassy silicate. 相似文献
144.
The aim of our study was to establish changes in activity of important in detoxification enzyme-glutathione S-transferase (GST): in alimentary tract, fat body and Malpighian tubules of Spodoptera exigua larvae being under cadmium and zinc exposure through the first as well as the second generation. There was registered enhancement of the enzyme activity in the fat body and the Malpighian tubules caused by zinc as well as its decrease in the Malpighian tubules under cadmium action. Amounts of metals in the alimentary tract were either several times higher than in the diet ingested by larvae or than in the fat body. Metal concentration in the fat body correlated with the level of the enzyme activity (positive correlation for zinc and negative for cadmium). The effect of metal action differentiated dependently on time exposition. 相似文献
145.
146.
147.
148.
Valme Jurado Angel Fernandez-Cortes Soledad Cuezva Leonila Laiz Juan Carlos Cañaveras Sergio Sanchez-Moral Cesareo Saiz-Jimenez 《Die Naturwissenschaften》2009,96(9):1027-1034
The conservation of rock-art paintings in European caves is a matter of increasing interest. This derives from the bacterial
colonisation of Altamira Cave, Spain and the recent fungal outbreak of Lascaux Cave, France—both included in the UNESCO World
Heritage List. Here, we show direct evidence of a fungal colonisation of rock tablets in a testing system exposed in Altamira
Cave. After 2 months, the tablets, previously sterilised, were heavily colonised by fungi and bacteria. Most fungi isolated
were labelled as entomopathogens, while the bacteria were those regularly identified in the cave. Rock colonisation was probably
promoted by the dissolved organic carbon supplied with the dripping and condensation waters and favoured by the displacement
of aerosols towards the interior of the cave, which contributed to the dissemination of microorganisms. The role of arthropods
in the dispersal of spores may also help in understanding fungal colonisation. This study evidences the fragility of rock-art
caves and demonstrates that microorganisms can easily colonise bare rocks and materials introduced into the cavity. 相似文献
149.
150.