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991.
根据国际上最近确定的全球N2 O各释放源及其释放量估算值 ,推算了全球N2 O年释放总量及各类源的相对贡献率。得出全球N2 O年释放总量约 1 4 .7TgN2 O -N ,其中自然源和人为源分别占 57%和 4 3 %。年释放总量中N的生物地球化学过程约贡献92 %、非生物作用过程仅贡献 8% ;与土壤有关的释放源约贡献 70 %、农业土壤贡献2 0 %。控制土壤尤其是农业土壤和热带森林土壤的N2 O释放量是控制全球大气N2 O浓度上升的关键 相似文献
992.
绿色机动车—燃料电池汽车 总被引:2,自引:0,他引:2
简要叙述了燃料电池汽车的技术特点,主要有:能量转化效率高,CO2排放量比内燃机汽车低,基本不产生有毒气体,不要充电。在此基础上较详细地介绍了世界各国的燃料电池汽车研究现状,并针对上海市机动车污染严重的现状,提出了发展燃料电池汽车及其相关产业的建议。 相似文献
993.
994.
Tuhkanen Sami Lehtilä Antti Savolainen Ilkka 《Mitigation and Adaptation Strategies for Global Change》1999,4(2):91-112
The reduction of carbon dioxide (CO2) emissions may be quite expensive and it is necessary to consider reduction measures for other anthropogenic greenhouse gases, such as methane (CH4) and nitrous oxide (N2O) as well. Their contribution to the total GHG emission from Finland is about 15–20%. In Finland most of the CH4 emissions are due to waste management, agriculture and burning processes. N2O emissions originate from burning processes, agriculture, industry and atmospheric deposition of nitrogen. The cost-effective reduction of the Finnish GHG emissions has been studied with the EFOM-ENV model, which is a quasi-dynamic linear energy system optimisation model. The target function to be minimised is the total discounted cost for the modelled system. In this study the model has been expanded to cover all well-known anthropogenic CO2, CH4 and N2O sources and reduction measures. The results indicate it is economic to reduce the emissions of CO2, CH4 and N2O in Finland. It is profitable to exploit the economic reduction potential of CH4 and N2O, because then the abatement of CO2 emissions does not need to be as extensive as when the reduction is aimed only at CO2 emissions. The inclusion of CH4 and N2O decreases the annual reduction costs about 20% in the year 2010. 相似文献
995.
《环境科学学报(英文版)》2023,35(3):277-289
Black carbon (BC) has importance regarding aerosol composition, radiative balance, and human exposure. This study adopted a backward-trajectory approach to quantify the origins of BC from anthropogenic emissions () and open biomass burning () transported to Xishuangbanna in 2017. Haze months, between haze and clean months, and clean months in Xishuangbanna were defined according to daily PM2.5 concentrations of >75, 35–75, and <35 µg/m3, respectively. Results showed that the transport efficiency density (TED) of BC transported to Xishuangbanna was controlled by the prevailing winds in different seasons. The yearly contributions to the effective emission intensity of and transported to Xishuangbanna were 52% and 48%, respectively. However, when haze occurred in Xishuangbanna, the average and contributions were 23% and 77%, respectively. This suggests that open biomass burning (BB) becomes the dominant source in haze months. Myanmar, India, and Laos were the dominant source regions of BC transported to Xishuangbanna during haze months, accounting for 59%, 18%, and 13% of the total, respectively. Furthermore, India was identified as the most important source regions of transported to Xishuangbanna in haze months, accounting for 14%. The two countries making the greatest contributions to transported to Xishuangbanna were Myanmar and Laos in haze months, accounting for 55% and 13%, respectively. BC emissions from Xishuangbanna had minimal effects on the results of the present study. It is suggested that open BB in Myanmar and Laos, and anthropogenic emissions in India were responsible for poor air quality in Xishuangbanna. 相似文献
996.
机动车排放模式的比较 总被引:1,自引:0,他引:1
介绍了当前使用频率比较高的几种用于道路交通和机动车辆排放计算和评估的模式,并对其进行了分类比较。 相似文献
997.
998.
石墨炉原子吸收光谱法测定海水中的三丁基锡 总被引:4,自引:0,他引:4
本文采用石墨炉原子吸收光谱法(GFAAS)测定海水甲苯抽提液中的三丁基锡。文中考察了14种基体改进剂对灵敏度的影响,选出了能显著提高测定灵敏度的Ca-Cr基体改进剂,以0.5/0.1mg/ml的浓度比例对8个实样进行了测定,其相对标准偏差(RSD)为3%,其特征浓度为7pg,回收率在88% ̄104%之间,成功地应用于近海沉积物对三丁基锡吸附规律的研究。 相似文献
999.
1000.
The depletion of fossil fuel reserves and increasing demands for diesel are considered to be important triggers for many of the initiatives that have been taken to search for possible sources for the production of biodiesel from materials available within the country. It is possible to produce biodiesel from waste/used cooking oils (WCO) that is comparable in quality to that of fresh vegetable oil. Not only does reuse of WCO, which can otherwise harm human health, reduce the burden on the government of treating oily wastewater, disposing of the waste, and maintaining public sewers, it also significantly lowers the production cost of biodiesel. In the process of frying, oil undergoes many reactions, leading to the formation of a number of undesirable compounds, such as polymers, free fatty acids, and many other chemicals. This poses challenges in the transesterification of WCO. This article covers different techniques in the production of biodiesel from WCO. It also compares combustion, emissions, and engine performance characteristics of biodiesel from WCO as well as factors affecting biodiesel production from WCO and its economic feasibility. 相似文献