全文获取类型
收费全文 | 954篇 |
免费 | 52篇 |
国内免费 | 364篇 |
专业分类
安全科学 | 58篇 |
废物处理 | 55篇 |
环保管理 | 89篇 |
综合类 | 520篇 |
基础理论 | 197篇 |
污染及防治 | 307篇 |
评价与监测 | 28篇 |
社会与环境 | 34篇 |
灾害及防治 | 82篇 |
出版年
2023年 | 16篇 |
2022年 | 53篇 |
2021年 | 41篇 |
2020年 | 30篇 |
2019年 | 27篇 |
2018年 | 45篇 |
2017年 | 47篇 |
2016年 | 45篇 |
2015年 | 71篇 |
2014年 | 82篇 |
2013年 | 98篇 |
2012年 | 95篇 |
2011年 | 96篇 |
2010年 | 69篇 |
2009年 | 61篇 |
2008年 | 66篇 |
2007年 | 58篇 |
2006年 | 40篇 |
2005年 | 38篇 |
2004年 | 21篇 |
2003年 | 25篇 |
2002年 | 26篇 |
2001年 | 26篇 |
2000年 | 23篇 |
1999年 | 26篇 |
1998年 | 22篇 |
1997年 | 20篇 |
1996年 | 22篇 |
1995年 | 22篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
排序方式: 共有1370条查询结果,搜索用时 234 毫秒
981.
Qidong Wang Jiashou Liu Shengyu Zhang Yuxi Lian Huaiyu Ding Xue Du Zhongjie Li Sena S. De Silva 《Ambio》2016,45(3):361-373
Results of a survey of 156 Chinese mitten crab (Eriocheir sinensis) grow-out farms around Hongze Lake
(118.48–118.72°E; 33.36–33.38°N) are reported. Area farmed has remained relatively
unchanged but production (59 932 t in 2012)
increased steadily over the last 7 years, indicative of the viability and
sustainability of the farming system that has gradually replaced intensive Chinese
major carp polyculture around Hongze Lake. Results showed that production range was
135–2400 kg ha−1 cycle−1
(mean 1144 ± 34). Crab yields correlated linearly to stocking density and conformed
to a normal distribution curve, with 66.7 % of farms yielding
900 kg ha−1 cycle−1 or more.
Yield was negatively correlated to pond size and capture size (p < 0.01), and farms with macrophyte coverage rate
lower than 30 % of water surface were significantly (p < 0.05) lower than those exceeding 30 %.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0722-0) contains supplementary material, which is available to authorized users. 相似文献982.
983.
An Du Genaro A. Gelves Donghun Koo Uttandaraman Sundararaj Richard Cairncross 《Journal of Polymers and the Environment》2013,21(1):8-15
Polylactide–montmorillonite composites were fabricated by melt-blending followed by compression molding, and water permeability of the composites was studied by both experiments and theoretical models. The water permeation in composites decreases with increasing concentration of montmorillonite. Specifically, at a concentration of 10 wt% of montmorillonite, the water permeation is 34 % less than in the neat polymer. Transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) results show that most of the montmorillonite particles are well-dispersed and randomly exfoliated in the polymer matrix. A fit of theoretical models to the permeation data estimates that montmorillonite platelets are mostly exfoliated in the polymer matrix and oriented randomly, which matches with results from WAXS and TEM. 相似文献
984.
Suitability analysis for greenway planning was developed in the Western culture. When applying a suitability analysis to a
very different sociocultural context such as China, it is necessary to identify what hinders or promotes it. Through an example
of Chongming Island, this article demonstrates how to apply a suitability analysis for greenway planning in China. Furthermore,
it argues that obstacles including a lack of data, peculiarity of capability scores within land use and a neglect of scientific
group involvement are encountered in the process of applying suitability methods in Chongming or China. Early and sustained
attention to such impediments could improve the success of suitability assessment in China. These research results are helpful
for the planning and implementation of Chongming greenways. 相似文献
985.
986.
A new strategy of heavy crude oil removal from contaminated soils was studied. The hexane-acetone solvent mixture was used to investigate the ability of solvent extraction technique for cleaning up soils under various extraction conditions. The mixtures of hexane and acetone (25 vol%) were demonstrated to be the most effective in removing petroleum hydrocarbons from contaminated soils and approx 90% of saturates, naphthene aromatics, polar aromatics, and 60% of nC7-asphaltenes were removed. Kinetic experiments demonstrated that the equilibrium was reached in 5 min and the majority of the oil pollutants were removed within 0.5 min. The effect of the ratio between solvent and soil on the extraction efficiency was also studied and results showed that the efficiency would increase following the higher solvent soil ratio. Then the multistage continuous extraction was considered to enhance the removal efficiency of oil pollutants. Three stages crosscurrent and countercurrent solvent extraction with the solvent soil ratio 6:1 removed 97% oil contaminants from soil. Clearly the results showed that the mixed-solvent of hexane and acetone (25 vol%) with character of low-toxic, acceptable cost and high efficiency was promising in solvent extraction to remove heavy oil fractions as well as petroleum hydrocarbons from contaminated soils. 相似文献
987.
988.
塔式太阳能热电站正常运行时会引发光污染问题。本文分析了塔式太阳能热电站产生光污染的原因以及光污染对人和生态环境产生的危害。在塔式太阳能电站选址、组件设计、安全防护以及配套设施方面,分别提出了有效的光污染防治措施,对于塔式太阳能热电站光污染的防治,提供了一定的理论指导。 相似文献
989.
山东新汶矿业集团翟镇煤矿通过不断引进、消化和吸收国内外先进生产技术,走科技创新之路,这个昔日饱受顶板破碎干扰、生产条件复杂的大型矿井在短短几年的时间内实现了采掘机械化、辅助自动化、控制智能化,先后有136项科技项目首开国内先河,其中32项达到了国际先进水平。为推动“科技兴矿”战略的实施,翟镇煤矿采取了一系列有效措施: 相似文献
990.
Spatial distribution of arsenic in the intertidal sediments of River Scheldt, Belgium 总被引:1,自引:0,他引:1
A study was carried out to assess the spatial distribution of arsenic in the intertidal sediments of the River Scheldt in Belgium. Sediment samples were collected from different locations along the River Scheldt up to 100 cm depth and analysed for the major physicochemical properties. The study reveals that the arsenic contents in the sediment samples vary in a wide range, from 2.3 to 140.2 mg kg(-1) dry weight. Moreover, the arsenic concentrations are generally below the background concentrations and remediation thresholds of arsenic in Flanders, Belgium. The occurrence of arsenic is found closely related to some physicochemical properties of the sediments. Arsenic has a strong positive correlation with organic matter and clay contents. On the contrary, a negative correlation exists between arsenic, sand and pH. It is recommended to develop and use organic matter control practices for lowering further accumulation of arsenic within the sediments. 相似文献