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Nicole?WellbrockEmail author Winfried?Riek Barbara?Wolff 《European Journal of Forest Research》2005,124(4):261-271
Based on the results of the atmospheric deposition classification of the year 1989, a methodical approach should be introduced,
which—based on the modelled total deposition rates—enables us to characterise the input situation of forest monitoring plots
and to delimit load areas in Germany. In 1989, the deposition situation in nearly 1,800 forest monitoring sites (BZE/extensive
Soil Condition Inventory) in Germany could be explained by four factors (or three, excluding sea salt impact) with the help
of a factor analysis. The factor values were grouped into six deposition types with typical compounds and regional patterns.
The classified input rates of the soil inventory plots adequately represent the stress situation and deposition changes in
Germany. The application of the statistical approach on the level of Brandenburg clarifies the special local input situation.
Due to the special combination of deposed elements, the sources of emissions can be characterised as well. When the soil inventory
is repeated, a project planned for 2006, this approach can be used in order to determine homogenous areas for stratified data
evaluation. 相似文献
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混氢改善汽油机低怠速性能研究 总被引:1,自引:0,他引:1
在一台加装了电控氢气喷射系统的四缸汽油机上,试验研究了混氢对发动机低怠速性能的影响。在怠速转速不变、维持进气混合气处于当量比的条件下,在0~6%的范围内逐渐增加氢气在总进气中的体积分数,测试了发动机转速分别为800、700、600 r/min时的低怠速性能。试验结果表明,纯汽油机怠速为800 r/min时,发动机稳定运行的燃料能量流量Ef为30.8 MJ/h,而当混氢分数增加至6.0%、怠速转速降至600 r/min时,Ef降低至18.6 MJ/h;随进气混氢体积分数的提高,发动机低怠速时的燃烧持续期缩短,HC、CO及NOx排放量降低,循环变动也减小。可见,进气掺氢可有效改善发动机的低怠速性能。 相似文献
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P. Merino J.M. Estavillo L.A. Graciolli M. Pinto M. Lacuesta A. Muñoz-Rueda C. Gonzalez-Murua 《Soil Use and Management》2002,18(2):135-141
Abstract. Nitrous oxide (N2 O) is involved in both ozone destruction and global warming. In agricultural soils it is produced by nitrification and denitrification mainly after fertilization. Nitrification inhibitors have been proposed as one of the management tools for the reduction of the potential hazards of fertilizer-derived N2 O. Addition of nitrification inhibitors to fertilizers maintains soil N in ammonium form, thereby gaseous N losses by nitrification and denitrification are less likely to occur and there is increased N utilization by the sward. We present a study aimed to evaluate the effectiveness of the nitrification inhibitor dicyandiamide (DCD) and of the slurry additive Actilith F2 on N2 O emissions following application of calcium ammonium nitrate or cattle slurry to a mixed clover/ryegrass sward in the Basque Country. The results indicate that large differences in N2 O emission occur depending on fertilizer type and the presence or absence of a nitrification inhibitor. There is considerable scope for immediate reduction of emissions by applying DCD with calcium ammonium nitrate or cattle slurry. DCD, applied at 25 kg ha–1 , reduced the amount of N lost as N2 O by 60% and 42% when applied with cattle slurry and calcium ammonium nitrate, respectively. Actilith F2 did not reduce N2 O emissions and it produced a long lasting mineralization of previously immobilized added N. 相似文献
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针对汽车冷起动排放的问题,论述了提高催化转化器入口温度和控制空燃比,它们能够缩短暖机时间,减少排放物,并且该论文还提出了提高入口温度的方法。 相似文献
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Guillermo E. Defossé Gabriel Loguercio Facundo J. Oddi Julio C. Molina P. Daniel Kraus 《Forest Ecology and Management》2011,261(12):2243-2254
Wildland fire is a natural force that has shaped most vegetation types of the world. However, its inappropriate management during the last century has led to more frequent and catastrophic fires. Wildland fires are also recognized as one of the sources of CO2 and other greenhouse gases (GHG) that influence global climate change. As one of the techniques used to reduce the risk of destructive wildfires, prescribed burning has the potential of mitigating carbon emissions, and effectively contributes to the efforts proposed as part of the Clean Development Mechanism within the Kyoto protocol. In order to apply this concept to a real case, a simulation study was conducted in pine afforestation in the Andean region of Patagonia, Argentina, with the objective of evaluating the potential of prescribed burning for reducing GHG emissions. The scenario was established for a ten year period, in which simulated prescribed burning was compared to the traditional management scheme, which included the probability of annual average of wildfire occurrence based on available wildfire statistics. The two contrasting scenarios were: (1) managed afforestation, affected by the annual average rate of wildfires occurred in the same type of afforestation in the region, without prescribed burning, and (2) same as (1) but with the application of simulated prescribed burning. In order to estimate carbon stocks, and CO2 removals and emissions, we followed the guidelines given for GHG inventories on the Agriculture, Forestry and Other Land Uses (AFOLU) sector of the International Panel on Climate Change (IPCC), while the terminology used was the established by IPCC (2003). Data of afforested area, thinnings, and biomass growth were taken from previous surveys in the study area. Downed dead wood and litter (forest fuel load, FFL) was estimated adjusting equations fitted to those fuels, based on field data. Results show that comparing the two scenarios, prescribed burning reduced CO2 emissions by 44% compared to the situation without prescribed burning. The prescribed burning scenario represented about 12% of the total emissions (prescribed burning plus wildfires). Furthermore, avoided wildfires by simulated prescribed burning allowed an additional 78% GHG emissions mitigation due to extra biomass growth. Simulated prescribed burning in commercial afforestation of Patagonia appears to be an effective management practice not only to prevent wildfires, but also an efficient tool to mitigate GHG emissions. However, more studies in different scenarios would be needed to generalize these benefits to other ecosystems. 相似文献
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通过大量试验,选择了Span80和OP4/Span80复配的乳化剂作为乙醇-柴油的助溶剂,配制成了均匀稳定的乙醇-柴油微乳液,并对乙醇-柴油微乳液的稳定性、密度、粘度、低热值和十六烷值等和发动机燃烧过程有密切联系的参数进行了研究,同时在YZ485D柴油机上和柴油作了排放对比试验。试验结果表明:和柴油相比,乙醇-柴油微乳液的NOx和碳烟排放有明显的降低,但是CO和THC(总碳氢)排放升高。 相似文献
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