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991.
生命周期评价及天然气基车用替代燃料的选择 总被引:1,自引:0,他引:1
介绍了生命周期评价方法在车用替代燃料选择方面的研究,通过实地考察我国天然气制甲醇联产二甲醚工艺,结合车辆技术,对天然气基代用燃料,包括压缩天然气、甲醇汽油、二甲醚的生命周期能量消耗和温室气体排放进行了评估,并与石油基燃料进行了比较,同时对燃料制备工艺与车辆技术进步所造成的影响进行了讨论。 相似文献
992.
993.
Yiming He Jackeline RiosMashrur Chowdhury Pierluigi PisuParth Bhavsar 《Transportation Research Part D: Transport and Environment》2012,17(3):201-207
In this paper, a forward power-train plug-in hybrid electric vehicle model with an energy management system and a cycle optimization algorithm is evaluated for energy efficiency. Using wirelessly communicated predictive traffic data for vehicles in a roadway network, as envisioned in intelligent transportation systems, traffic prediction cycles are optimized using a cycle optimization strategy. This resulted in a 56-86% fuel efficiency improvements for conventional vehicles. When combined with the plug-in hybrid electric vehicle power management system, about 115% energy efficiency improvements were achieved. Further improvements in the overall energy efficiency of the network were achieved with increased penetration rates of the intelligent transportation assisted enabled plug-in hybrid electric vehicles. 相似文献
994.
Philippe Koubbi Guy Duhamel Jean-Henri Hecq Cristina Beans Christophe Loots Patrice Pruvost Eric Tavernier Marino Vacchi Carole Vallet 《Journal of Marine Systems》2009,78(4):547
Since the article published by Loeb et al. [Loeb, V.J., Kellermann, A., Koubbi, P., North, A.W., White, M., 1993. Antarctic larval fish assemblages: a review. Bull. Mar. Sci. 53(2), 416–449.] about Antarctic ichthyoplankton, many surveys were carried out in different sectors of the Southern Ocean focusing on different aspects of the ecology of fish larvae. Some of these researches were conducted in the Subantarctic Kerguelen Islands and others on the continental shelf off Terre Adélie and Georges V land. Oceanographic and geographic features influence fish larvae ecology such as island mass effects, gyres, canyons. Antarctic fishes show also temporal segregation of spawning which induces temporal succession of early stage larvae. This avoids competition and probably the predation on early stages for species having few recruits. In that case, we have to understand how these larvae can deal with the match–mismatch with their preys and how they find sufficient food to survive. But our knowledge on Antarctic fish larvae is still insufficient as we do not know larvae for quite a lot of species and because of the difficulty to sample during winter. 相似文献
995.
应力和干湿循环共同作用下硫酸根在混凝土中传输试验研究 总被引:1,自引:0,他引:1
对混凝土试件施加应力后,按一定周期将其在硫酸钠溶液中浸泡,再风干形成干湿循环作用。采用钻芯、分层切片、研磨提取水泥石粉末样本进行化学分析,测定不同深度处混凝土的硫酸根离子含量;研究在于湿循环作用下,混凝土受到的拉应力、压应力对硫酸根离子在混凝土内传输的影响规律。结果表明:拉应力对硫酸根离子由外部侵蚀溶液向混凝土内的传输具有加速效果,且随拉应力水平的增加而增大;压应力对硫酸根离子在混凝土内的传输具有一定的抑制作用,但与压应力水平没有确切的相关性。 相似文献
996.
未来我国的汽车检测领域应当朝向标准化、一体化、智能化与制度化方向发展,以可持续发展观为指导,在加速发展检测技术的同时实现对汽车检测技术的提高。文章针对我国当前检测技术的发展现状进行有效分析,并列举了几种对汽车部件检测的具体方法。 相似文献
997.
随着我国人工智能时代的来临,为汽车行业的经营与发展,提供了有利的契机。传感器作为汽车的重要组成部分,不仅能够为驾驶员提供舒适的操作性能,还可以对路况信息及运行状态,进行实时准确的监测。极大程度提高了汽车驾驶过程中的安全系数。而将人工智能技术应用到汽车传感器中,使各种传感器的使用,发生了质的变化。也为我国汽车行业的发展,起到了较大的推动作用。文章利用汽车传感器的工作原理及主要特点,结合人工智能时代下汽车传感器的现状,浅谈一下智能汽车传感器的未来发展趋势。 相似文献
998.
As market price, shipping freight rates should in theory be stationary, but most empirical tests have found them to be non-stationary. To examine the causes of this theoretical–empirical inconsistency, we investigate the sensitivities of the stationarity of shipping freight rates from two perspectives: sample length and sample window. Longer samples are found not sufficient to make them stationary. Instead, sample windows separated by structural breaks are tested as stationary. Moreover, freight rates are found to have entered into a new phase since the 2008 financial crisis. This study contributes to the literature on the stationarity of shipping freight rates by providing an explanation for the theoretical–empirical inconsistency. 相似文献
999.
The present work compares, on a fundamental basis, the performance and emissions of a diesel-engined large van running on eight legislated driving cycles, namely the European NEDC, the U.S. FTP-75, HFET, US06, LA-92 and NYCC, the Japanese JC08 and the Worldwide WLTC 3-2. It aims to identify differences and similarities between various influential driving cycles valid in the world, and correlate important cycle metrics with vehicle exhaust emissions. The results derive from a computational code based on an engine mapping approach, with experimentally derived correction coefficients applied to account for transient discrepancies; the code is coupled to a comprehensive vehicle model. Soot as well as nitrogen monoxide are the examined pollutants. Only the driving cycle schedule is under investigation in this work, and not the whole test procedure, in order to identify vehicle speed (transient) effects of the individual cycles only. The recently developed WLTC 3-2 is the cycle with a very broad and at the same time dense coverage of the vehicle’s/engine’s operating activity, being thus particularly representative of ‘average’ real-world driving. Even broader is the distribution of the US06, whereas particularly thin and narrow that of the modal NEDC. It is also revealed that the more transient cycles, e.g. the NYCC or the US06, are also the ones with the highest amount of engine-out pollutant emissions and energy consumption. Relative positive acceleration and stops per km are found to correlate very well with energy and fuel consumption and all emitted pollutants. 相似文献
1000.
文章建立了增压柴油机米勒循环结合EGR(废气再循环)的热力学模型,利用模型分析了柴油机设计参数对其性能的影响,为米勒循环结合EGR的增压柴油机参数设计提供了理论依据。研究表明,要使WP7柴油机的热效率和平均有效压力同时提高,增压系统效率需大于0.7。同时,以柴油机转速为1 500 r/min外特性工况点的NO_X排放下降50%、最高爆发压力不超过原机为约束条件,对WP7柴油机参数进行了优化设计。优化结果表明,该方法将有效压缩比从18降低到15.5,再结合12%的EGR率,可以在保持柴油机经济性、动力性与原机基本一致的前提下,将NO_X排放下降50%以上。 相似文献