A carbon supported Pd（Pd/C） catalyst used as the anodic catalyst in the direct formic acid fuel cells（DFAFC） was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate（EDTA） a...A carbon supported Pd（Pd/C） catalyst used as the anodic catalyst in the direct formic acid fuel cells（DFAFC） was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate（EDTA） as stabilizer and complexing agent. This method is very simple. The average size of the Pd particles in the Pd/C catalyst prepared with the improved complex reduction method is as small as about 2.1 nm and the Pd particles in the Pd/C catalyst possess an excellent uniformity. The Pd/C catalyst shows a high electrocatalytic activity and stability for the formic acid oxidation.展开更多
Vascular plants possess an enzyme system that detoxifies cyanide by converting it to the amino acid asparagine. Hybrid willows （Salix matsudana Koidz×Salix alba L.） were exposed to cyanide to determine whether ...Vascular plants possess an enzyme system that detoxifies cyanide by converting it to the amino acid asparagine. Hybrid willows （Salix matsudana Koidz×Salix alba L.） were exposed to cyanide to determine whether willows can transport and metabolize this compound. Pre-rooted trees were grown in different environmental compartments, spiked or irrigated with potassium cyanide at 24.0±0.5℃. Cyanide in compartments, in air and in tissues of plants was analyzed spectrophotometrically. Results from this study indicated that large amounts of applied cyanide was removed from the systems during the presence of willows. Growing compartments of plants have a strong influence on the removal rates of cyanide. Little or no initial cyanide was detected in plant materials. Volatilization of cyanide was not occurring. Mass balance studies showed that applied cyanide was significantly metabolized during transport through willows cuttings. However, there was a clear difference between the metabolism rates of cyanide by willows exposed to different environmental compartments. The highest cyanide metabolism rate was found at the treatment with willows growing in hydroponic solution with a metabolism rate of 2.44 mgCN/（kg, d）, followed by willows growing in sand with a value of 1.02 mgCN/（kg·d）. The lowest metabolism rate had the willows growing in soils（0.43 mgCN/（kg·d）. In conclusion, transport and metabolism of cyanide in plants is likely and phytoremediation of cyanide is a feasible option for cleaning soils and water contaminated with cyanide.展开更多
基金Supported by the "863" Program of Science and Technology Ministry of China(Nos.2006AA05Z137, 2007AA05Z143 and 2007AA05Z159)National Natural Science Foundation of China(Nos.20433060, 20473038, 20573057 and 20703043)the Natural Science Foundation of Jiangsu Province, China(No.BK2006224).
文摘A carbon supported Pd（Pd/C） catalyst used as the anodic catalyst in the direct formic acid fuel cells（DFAFC） was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate（EDTA） as stabilizer and complexing agent. This method is very simple. The average size of the Pd particles in the Pd/C catalyst prepared with the improved complex reduction method is as small as about 2.1 nm and the Pd particles in the Pd/C catalyst possess an excellent uniformity. The Pd/C catalyst shows a high electrocatalytic activity and stability for the formic acid oxidation.
文摘Vascular plants possess an enzyme system that detoxifies cyanide by converting it to the amino acid asparagine. Hybrid willows （Salix matsudana Koidz×Salix alba L.） were exposed to cyanide to determine whether willows can transport and metabolize this compound. Pre-rooted trees were grown in different environmental compartments, spiked or irrigated with potassium cyanide at 24.0±0.5℃. Cyanide in compartments, in air and in tissues of plants was analyzed spectrophotometrically. Results from this study indicated that large amounts of applied cyanide was removed from the systems during the presence of willows. Growing compartments of plants have a strong influence on the removal rates of cyanide. Little or no initial cyanide was detected in plant materials. Volatilization of cyanide was not occurring. Mass balance studies showed that applied cyanide was significantly metabolized during transport through willows cuttings. However, there was a clear difference between the metabolism rates of cyanide by willows exposed to different environmental compartments. The highest cyanide metabolism rate was found at the treatment with willows growing in hydroponic solution with a metabolism rate of 2.44 mgCN/（kg, d）, followed by willows growing in sand with a value of 1.02 mgCN/（kg·d）. The lowest metabolism rate had the willows growing in soils（0.43 mgCN/（kg·d）. In conclusion, transport and metabolism of cyanide in plants is likely and phytoremediation of cyanide is a feasible option for cleaning soils and water contaminated with cyanide.
