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J. Williams 《Journal of Atmospheric Chemistry》2005,50(1):101-102
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In a commentary paper, Bamber et al. (Nat Clim Change 3:424–427, 2016) respond to our recent assessment (De Vries and Van de Wal Clim Change 1–14, 2015) of their expert judgment based study on projections of future sea level rise due to the melting of the large ice sheets (Bamber and Aspinall Nat Clim Chang 3:424–427, 2013). In this response we comment on their remarks. 相似文献
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Summary The CH4 emission rates from Chinese rice fields have been measured in five typical areas representing all of the five major rice culture regions in People's Republic of China (P.R. China). Four types of diurnal variations (afternoon peak, night peak, afternoon-night double peaks and random pattern) of CH4 emission rates have been found. The first pattern was normally found in clear weather, the second and the third types were only found occasionally in particular place, while the fourth were found in cloudy or rainy weather. Due to the irregular pattern of the methane production observed in the morning-afternoon comparison experiment, the transport pathway influenced by certain factors, may be the major factor governing the diurnal variation of CH4 emission. Seasonal variation patterns of CH4 emission differ slightly with different field locations, where climate system, cropping system and other factors are different. Two and three emission peaks were generally found during single and early rice vegetation periods, with the peak magnitude and time of appearance differing to small degree in individual sites. A decreasing trend of seasonal variation was always observed in late rice season. A combination of seasonal change of transport efficiency and that of CH4 production rate in the paddy soil explains well the CH4 emission. The role of rice plant in transporting CH4 varied over a large range in different rice growing stages. The reasons for internnual changes of CH4 flux are not yet clear.Great spatial variation of the CH4 emission has been found, which can be attributed to the differences in soil type and soil properties, local climate condition, rice species, fertilizer and water treatment. Experiments showed that while the application of some mineral fertilizers will reduce the CH4 emission and CH4 production in the soil, the application of organic manure will enhance CH4 emission and CH4 production in the soil. Any measures which can get off easily decomposed carbon from organic manure may reduce C supply for CH4 production, and hence reduce CH4 emission. Fermented sludges from biogas generators and farmyard-stored manure seem to be promising. In some parts of China, separate application of the organic and mineral manure instead of mixed application could be another option. Frequent Scientific drainage and ridge cultivation, which are often used water management techniques in Chinese rice agriculture, have been proved in the experiments to be a very efficient mitigation measures to reduce CH4 emission from rice fields.By summarizing the present available data, China's rice fields contribute about 13.3 Tg yr–1 (11.4–15.2) CH4 to the atmosphere. The total methane emission from global rice fields can be estimated 33–60 Tg yr–1, much less than the estimates made before.If we extrapolate the measured data in China with a consideration of measured data in other Asian country, the total global emission of CH4 from rice fields are estimated to be about 35–60 Tg yr–1
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在众多相关文献中,P2P信任管理模型设计更多考虑效率,抵抗恶意攻击性等方面,而"公平性"作为影响网络整体性能提高的重要因素却没有得到重视.将影响公平性的行为分类,着重考虑"非恶意行为"所造成的"隐性不公平",最后通过仿真验证了信任管理模型可以在实现负载均衡的同时达到降低无效下载次数的目的. 相似文献