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991.
The photovoltaic conversion efficiency for near-infrared (NIR) sunlight is improved successfully by dye sensitization of bulk heterojunction polymer solar cells, in which the active layer was prepared by a ternary blend of poly(3-hexylthiophene), a fullerene derivative (1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene), and an NIR dye, silicon phthalocyanine bis(trihexylsilyl oxide). The mechanism of the NIR-dye sensitization is studied by femtosecond transient absorption spectroscopy. 相似文献
992.
Torben R. Christensen Marcin Jackowicz-Korczyński Mika Aurela Patrick Crill Michal Heliasz Mikhail Mastepanov Thomas Friborg 《Ambio》2012,41(3):207-217
This article reports a dataset on 8 years of monitoring carbon fluxes in a subarctic palsa mire based on micrometeorological eddy covariance measurements. The mire is a complex with wet minerotrophic areas and elevated dry palsa as well as intermediate sub-ecosystems. The measurements document primarily the emission originating from the wet parts of the mire dominated by a rather homogenous cover of Eriophorum angustifolium. The CO2/CH4 flux measurements performed during the years 2001–2008 showed that the areas represented in the measurements were a relatively stable sink of carbon with an average annual rate of uptake amounting to on average ?46 g C m?2 y?1 including an equally stable loss through CH4 emissions (18–22 g CH4–C m?2 y?1). This consistent carbon sink combined with substantial CH4 emissions is most likely what is to be expected as the permafrost under palsa mires degrades in response to climate warming. 相似文献
993.
Soedarini B Klaver L Roessink I Widianarko B van Straalen NM van Gestel CA 《Chemosphere》2012,87(4):333-338
Metal pollution e.g. copper, in water bodies occurs worldwide. Although copper is an essential trace metal, at certain levels it is still considered as pollutant. The aim of this study was to investigate the effect of exposure concentration on copper bioaccumulation in marbled crayfish (Procambarus sp.) by determining uptake and elimination kinetics. Crayfish were exposed to sub-lethal copper concentrations (average measured concentrations of 0.031 and 0.38 mg Cu L−1) for 14 d and transferred to copper-free water for another 14 d. At different time points during the uptake and elimination phases copper concentrations were measured in five organs (exoskeleton, gills, muscle, ovaries and hepatopancreas). At 0.031 mg Cu L−1, copper levels in the crayfish organs were not significantly increased compared to the control animals, suggesting effective regulation. Exposure to 0.38 mg Cu L−1 did lead to not significantly increased copper levels in muscles and ovaries, while the gills and exoskeleton, which are in direct contact with the water, showed significantly higher copper concentrations. In these four organs, copper showed fast uptake kinetics with equilibrium reached within 10 d of exposure. Copper accumulation was highest in the hepatopancreas; uptake in this storage organ steadily increased with time and did not reach equilibrium within the 14-d exposure period. Copper accumulation levels in the marbled crayfish found in this study were hepatopancreas > gills > exoskeleton > muscle. 相似文献
994.
995.
Visser A Kroes J T H van Vliet M Blenkinsop S Fowler HJ Broers HP 《Journal of contaminant hydrology》2012,127(1-4):47-64
The Keersop catchment (43km(2)) in the south of The Netherlands has been contaminated by the emissions of four zinc ore smelters. The objective of this study was to assess the effects of future projected climate change on the hydrology and the leaching of heavy metals (i.e. Cd and Zn) in the catchment. The numerical, quasi-2D, unsaturated zone Soil Water Atmosphere Plant model was used with 100-year simulated daily time series of precipitation and potential evapotranspiration. The time series are representative of stationary climates for the periods 1961-1990 ("baseline") and 2071-2100 ("future"). The time series of future climate were obtained by downscaling the results of eight regional climate model (RCM) experiments, driven by the SRES A2 emissions scenario, using change factors for a series of climate statistics and applying them to stochastic weather generator models. The time series are characterized by increased precipitation in winter, less precipitation in summer, and higher air temperatures (between 2°C and 5°C) throughout the year. Future climate scenarios project higher evapotranspiration rates, more irrigation, less drainage, lower discharge rates and lower groundwater levels, due to increased evapotranspiration and a slowing down of the groundwater system. As a result, lower concentrations of Cd and Zn in surface water are projected. The reduced leaching of heavy metals, due to drying of the catchment, showed a positive impact on a limited aspect of surface water quality. 相似文献
996.
Rüdel H Müller J Quack M Klein R 《Environmental science and pollution research international》2012,19(3):772-783
Background and aims
Hexabromocyclododecane (HBCD) is a brominated flame retardant used mainly in polystyrene foam as well as in textile applications. In recent years, measures were taken to reduce HBCD emissions during its production and use. To evaluate the efficacy of these measures, a monitoring project was initiated with fish as bioaccumulation indicators. 相似文献997.
Manaca MN Grimalt JO Gari M Sacarlal J Sunyer J Gonzalez R Dobaño C Menendez C Alonso PL 《Environmental science and pollution research international》2012,19(3):756-762
Introduction
We report on the analysis of 4,4′-dichlorodiphenyltrichloroethane (4,4′-DDT) and its metabolites in thatch and branch samples constituting the wall materials of dwellings from South African subtropical areas. This approach was used to assess the exposure to DDT in the residents of the dwellings after indoor residual spraying (IRS) following recommended sanitation practices against malaria vectors. 相似文献998.
Bacterial community profiles from sediments of the Anacostia River using metabolic and molecular analyses 总被引:1,自引:0,他引:1
Bushaw-Newton KL Ewers EC Velinsky DJ Ashley JT Macavoy SE 《Environmental science and pollution research international》2012,19(4):1271-1279
Background aim and scope
Though the tidal Anacostia River, a highly polluted riverine system, has been well characterized with regard to contaminants, its overall resident bacterial populations have remained largely unknown. Improving the health of this system will rely upon enhanced understanding of the diversity and functions of these communities. Bacterial DNA was extracted from archived (AR, year 2000) and fresh sediments (RE, year 2006) collected from various locations within the Anacostia River. Using a combination of metabolic and molecular techniques, community snapshots of sediment bacterial diversity and activity were produced. 相似文献999.
Simultaneous immobilization of metals and arsenic in acidic polluted soils near a copper smelter in central Chile 总被引:1,自引:0,他引:1
Cárcamo V Bustamante E Trangolao E de la Fuente LM Mench M Neaman A Ginocchio R 《Environmental science and pollution research international》2012,19(4):1131-1143