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阐述了当今柴油机降低NOx和PM排放的各种后处理技术.介绍了同时降低NOx和PM的DPNR技术、SCRTR技术及低温等离子体技术,分析了这些技术的主要原理.简要介绍了德国EMITEC公司的PM-METALITTM颗粒捕集器及德尔福的DEC/LNX技术.指出了同时降低NOx和PM的后处理技术将成为未来研究的热点. 相似文献
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全球新能源技术发展:以技术垄断与技术扩散为视角 总被引:1,自引:0,他引:1
概述了全球新能源技术发展格局,以技术垄断和技术扩散为视角分析了新能源技术垄断与技术扩散的形成机理与关系,介绍了发达国家新能源技术垄断与技术扩散的模式,并指出未来我国新能源技术发展的两条路径. 相似文献
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在煤矿开采和设计时,需要获取大量的位置数据.随着测绘技术的发展,一些新的测绘技术被应用于煤矿领域,极大地方便了煤矿生产和设计.通过分析现有的测绘新技术,主要有激光测距仪测绘技术、全站仪测绘技术、GPS测绘技术、GIS测绘技术、遥感技术和RS测绘技术,探讨了这些技术在煤矿生产中的应用. 相似文献
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以新一代燃烧技术的发展、演变及特征为出发点,从燃料改质技术、缸内净化技术和后处理技术3方面归纳了柴油机清洁排放控制技术研究的发展。重点分析了各种技术的特点以及对发动机排放的作用和影响,最后讨论了发动机清洁排放控制技术的未来发展趋势。 相似文献
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随着航空发动机技术的发展和对适航安全性认识的深入,国外适航规章愈加完善,我国的适航研究显得更加迫切。本文分析了FAA25部361条款的四个版本,并分析了历次修订的原因及背景,可为发动机扭矩适航工作人员提供借鉴。 相似文献
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《Power Engineering Review, IEEE》1992,12(3):11-14
The characteristics of a power system that have become of increased importance because of interconnection are discussed. They are: very small damping of disturbances; the need for more voltage support; much more complexity in design, operation, control, protection, and analysis; and much more pervasive and numerous controls. Some new problems introduced by interconnection are examined. They are: the appearance of spontaneous tie-line power oscillations under certain line loading conditions; the appearance of voltage instability with resulting voltage collapse; and widespread blackouts 相似文献
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This paper describes work on a program directed toward assessing the prospects for development of more efficient heat-exchange equipment. Improved equipment leads to more efficient thermal systems and more effective waste-heat recovery. Heat-transfer enhancement is a vital part of this development effort.Sources of information on heat-transfer enhancement are briefly reviewed. Applications are discussed, with emphasis on those techniques which have made the transition from the laboratory to full-scale industrial equipment. Typical reports of the benefits of enhancement are cited. Factors affecting commercial development and use are also discussed. 相似文献
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The flow and heat-transfer characteristics of the free convection micropolar flow are described. It is found that decreasing rates of heat-transfer can be achieved by making the Newtonian solvent more and more micropolar. The micropolar characteristics are determined by the two non-dimensional parameters R (an index to microstructure character) and A (an index to substructure character). The effect of R is more pronounced on the flow and temperature fields while that of A is relatively less. 相似文献
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高层建筑作为现今城市发展中土地集约利用的一种有效解决方案,越来越普遍为城市规划部门所鼓励,越来越多被地产开发商所采用。高层建筑中燃气供应的安全性与可靠性也越来越受到业界的重视。主要探讨了高层建筑燃气管道设计及设计过程中的问题。 相似文献
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为了使电网的短路电流计算和开关开断能力校核能有一个科学合理的依据,降低对开关设备的遮断能力要求在分析IEC 909标准、ANSI标准及暂态稳定计算短路电流方法的基础上,提出了以暂态电抗Xd忆作为电机参数进行短路电流工程计算方法,并以PSCAD/EMTDC搭建IEEE 9的动态仿真模型,以动态仿真结果为基准,给出了2个标准的精确度,把提出的短路电流计算方法与根据IEC 909标准、ANSI标准及机电暂态仿真计算的结果进行了比较分析,结果显示基于暂态电抗Xd忆短路电流计算方法具有较好的精确性,且可以明显降低电网短路电流评估计算值。 相似文献
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Application of high‐resolution NVD differencing schemes to the FTn finite volume method for radiative heat transfer 下载免费PDF全文
In this work, the STEP scheme and several schemes based on the normalized variable diagram (NVD), such as MINMOD, GAMMA, CLAM, NOTABLE, MUSCL, CUBISTA, SMART, WACEB, and VANOS schemes, are evaluated for solving the radiative transfer equation. Two‐dimensional and three‐dimensional rectangular enclosures containing transparent, emitting–absorbing, emitting–absorbing–scattering, or nonhomogeneous participating media are investigated using the modified FTn finite volume method. Although the NVD schemes are much more accurate than the STEP scheme, but they have more time‐consuming and require more iterations. Moreover, most of them often necessitate underrelaxation to ensure convergence. Results show that the MINMOD and GAMMA schemes are still much less accurate than other NVD schemes, but they converge the fastest of the NVD schemes, and do not require underrelaxation. Although the VANOS, WACEB, and SMART schemes give more accurate solutions, they are not competitive with other NVD schemes. However, the CLAM, NOTABLE, and CUBISTA schemes are relatively fast and accurate. 相似文献