全文获取类型
收费全文 | 152篇 |
免费 | 2篇 |
专业分类
废物处理 | 5篇 |
环保管理 | 4篇 |
综合类 | 65篇 |
基础理论 | 39篇 |
污染及防治 | 29篇 |
评价与监测 | 3篇 |
社会与环境 | 8篇 |
灾害及防治 | 1篇 |
出版年
2020年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2008年 | 4篇 |
2007年 | 9篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1985年 | 4篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1973年 | 2篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1961年 | 2篇 |
1960年 | 4篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1955年 | 1篇 |
1954年 | 1篇 |
1952年 | 1篇 |
1951年 | 1篇 |
1950年 | 1篇 |
1934年 | 1篇 |
1933年 | 1篇 |
1931年 | 2篇 |
1927年 | 2篇 |
1925年 | 1篇 |
1924年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 156 毫秒
11.
Of the waste generated from electricity distribution networks, wooden posts treated with chromated copper arsenate (CCA) and ceramic insulators make up the majority of the materials for which no effective recycling scheme has been developed. This study aims to recycle and reuse this waste as reinforcement elements in polymer composites and hybrid composites, promoting an ecologically and economically viable alternative for the disposal of this waste. The CCA wooden posts were cut, crushed and recycled via acid leaching using 0.2 and 0.4 N H2SO4 in triplicate at 70 °C and then washed and dried. The ceramic insulators were fragmented in a hydraulic press and separated by particle size using a vibrating sieve. The composites were mixed in a twin-screw extruder and injected into the test specimens, which were subjected to physical, mechanical, thermal and morphological characterization. The results indicate that the acid treatment most effective for removing heavy metals in the wood utilizes 0.4 N H2SO4. However, the composites made from wood treated with 0.2 N H2SO4 exhibited the highest mechanical properties of the composites, whereas the use of a ceramic insulator produces composites with better thermal stability and impact strength. This study is part of the research and development project of ANEEL (Agência Nacional de Energia Elétrica) and funded by CPFL (Companhia Paulista de Força e Luz). 相似文献
12.
13.
The uptake and accumulation of the traffic-related platinum group elements (PGE) Pt, Pd and Rh by the aquatic fauna was investigated. Zebra mussels, eels and barbels were maintained in water containing either road dust or ground catalytic converter material. Following the exposure, samples of fish liver and kidney, as well as the soft tissues of the mussels, were analysed. Our results revealed that all three catalytic noble metals were accumulated by aquatic organisms. The highest bioavailability was found for Pd, followed by Pt and Rh. The concentration factor of Pd forDreissena polymorpha was 5 times higher compared with Pd and only 6 times lower than the essential element Cu. With regard to the increasing emission of Pd the level of this metal has to be monitored very carefully in the environment. 相似文献
14.
15.
16.
17.
18.
19.
Katrin Palitzsch Sabine Göllner Kristina Lupa Jörg Matschullat Corinna Messal Kirsten Pleßow Mandy Schipek Ivonne Schnabel Christian Weller Frank Zimmermann 《Environmental Sciences Europe》2005,17(4):231-241
The trend of rising ozone concentrations in forest ecosystems and the phytotoxicity of ozone demand a realistic risk assessment according to an internationally accepted and flux-based quality standard. Ozone fluxes within the canopy are influenced by chemical gas-phase reactions with nitrogen oxide and biogenic hydrocarbons and by surface deposition processes. Therefore, a differentiation of the ozone flux within the canopy is needed between stomatal uptake and other transport pathways. The Eddy Covariance technique is the method of choice for the determination of trace gas fluxes relevant for ozone chemistry. This method is also used for stomatal conductance measurements based on evapotranspiration fluxes and for emission measurements of biogenic hydrocarbons by PTR-MS. Although considerably research efforts were directed to canopy measurements in recent years, the underlying processes are not fully understood yet. Thus, major differences occur in the ratios of stomatal ozone uptake, non-stomatal deposition and gas-phase chemistry between different studies. Furthermore, the vertical concentration gradients within the canopy measured at several forest sites are rather inconsistent and the existing deposition models do rarely account for chemical transformation and detoxification processes. Only a simultaneous measurement of all photochemically relevant trace gases, plant physiological parameters at different sites and forest species over entire vegetation periods, and model parameterization according to the measurement results from the experimental sites will contribute to the clarification of the canopy processes and will ensure realistic risk assessments. 相似文献
20.
Dr. Roland Zimmermann Urs Lauper Anja Streicher Renate Huch Albert Hugh 《黑龙江环境通报》1995,15(12):1121-1124
In a series of 2961 consecutive cases with second-trimester biochemical triple screening for Down's syndrome and neural tube defect (NTD), ten (0.3 per cent) showed an apparent increased risk for both conditions. Three cases had chromosomal abnormalities, namely trisomy 16 confined to the placenta. Since placental trisomy 16 as well as cases with increased alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) are associated with (intrauterine growth retardation (IUGR), oligohydramnios, and fetal demise, at least some cases with this atypical biochemical profile could be explained by this chromosomal abnormality. From our results we recommend that in cases with increased risk for both Down's syndrome and NTD, fetal karyotyping should preferably be done on a placental biopsy, especially when ultrasound in the absence of anomalies demonstrates early IUGR. 相似文献