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151.
在线衍生化吹扫捕集-气相色谱/质谱分析水中的五氯酚   总被引:1,自引:0,他引:1  
建立了通过乙酸酐衍生化-吹扫捕集-气相色谱/质谱分析水中五氯酚的新方法,探讨了吹扫时间、样品池温度、离子强度以及衍生化试剂的加入量等条件对捕集效果的影响。结果表明:采用吹扫时间25min、样品池温度60℃、离子强度20%氯化钠以及衍生化试剂的量200μl等条件对水中的五氯酚有较好的捕集效果,用于水中五氯酚的测定,结果满意。  相似文献   
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Vietnam, in the ongoing transition to market economies, has to cope with high rural poverty and a dramatic process of forest loss and environment degradation, particularly in the mountainous regions. The government considers rural poverty as the main cause of environment degradation, associated with slash-and-burn cultivation and to an unclear definition of property rights on forest land. In 1993, the government launched a Forest Land Allocation programme aiming to lease forest lands to individual households and, on this basis, to solve food security problems, halt the increasing environment degradation and preserve the remaining forests.To evaluate the results of this land reform policy, two upland pilot communes have been intensively monitored. The environmental and economic impacts of the forest land reform allocation in the two study areas are presented, after providing a background on the Vietnamese situation of mountain zones. On the basis of these findings, it is discussed as to whether the current forest land allocation process may actually promote local development and natural resources conservation, and under what conditions. Deforestation problems must be tackled also with new macroeconomic policies (e.g. credit programmes to support sustainable agriculture practices) and social policy (e.g. reduction of demographic pressure), together with the reform of the State institutions (e.g. State Forest Enterprises) involved in management of the forest areas.  相似文献   
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A batch recycle removal of copper ions from an industrial effluent by means of copper foam cathodes was tested. A constant current of 750 A was applied to the cell in order to perform the reduction. Copper depletion was investigated at different solution flow rates and a removal greater than 98% was obtained with a flow rate of 1000 l/h. The influence of initial metal concentration on copper deposition and current efficiency is also discussed.  相似文献   
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A life cycle assessment (LCA) of a domestic cooker hood was conducted. Cradle-to-grave analysis was performed using the GaBi software with Eco-Indicator 99 (Egalitarian Approach). The most polluting phases were “manufacturing” and “use”, the environmental impact being affected especially by production materials and the electricity consumed during the product’s lifespan. The study also highlighted that the hood’s environmental impact is closely related to the local power grid mix. This aspect was further analyzed by entering the data for operating it both in Italy and in France. Finally, the improvements obtained by replacing the single-phase electrical motor with an inverter-driven three-phase induction one and the halogen lamps with Light Emitting Diode (LED) lamps were assessed with the LCA. These changes entail an improvement of the environmental impact of 36% in Italy and of 24% in France.  相似文献   
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