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介绍了一种PH1575型GPS接收机专用集成电路,它是一种双极性硅单片集成电路,具有集成度高、功耗低、相位噪声优良的优点,适用于要求成本低、集成度高、电池供电的便携式GPS接收机。 相似文献
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In recent years, renewable energy can be seen as one of the important prospect of today's research, as it is likely to enlighten the lives of millions of people by fulfilling demand of electricity in their daily life. The present work focuses on the development of optimal hybrid energy system sizing model based on comparative analysis of particle swarm optimization, genetic algorithm and Homer software for energy index ratio of 1. The model also incorporates renewable fraction, emissions of carbon di oxide from diesel generator, net present cost and cost of energy. The system is developed to supply the demand of 7 un-electrified villages of Dhauladevi block of Almora district in Uttarakhand, India with the help of the available resources of solar, hydro, biomass and biogas energy along with the addition of diesel generator, for meeting out the energy deficit. From the optimization results, minimum cost of energy and maximum renewable fraction are obtained as 5.77 Rs/kWh and 92.6% respectively. 相似文献
96.
为解决供水工程中的过剩水头问题,常在有压输水管道中配置合适的消能装置,转叶孔板螺旋流消能是一种新型的内消能方式,通过转叶孔板螺旋流消能装置的水力特性试验,可知影响转叶孔板螺旋流消能效率的主要影响因素有雷诺数Re、转叶孔板开口角度和孔板之间的相互扭转角度,还有试验装置结构的设置。根据试验数据计算分析各个影响因素对消能效率的影响。结果表明,转叶孔板螺旋流消能效率与转叶孔板之间的扭转角成正比,与雷诺数成正比,与转叶板的开口角度成反比。试验装置在进口段和出口段设置管径突变均对消能有利,该装置比与其消能原理类似的孔板消能装置更实用,且消能效率更高,对下游建筑物设施起到良好的保护作用,可推广应用。 相似文献
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T.V. Santosh R.K. SarafA.K. Ghosh H.S. Kushwaha 《International Journal of Pressure Vessels and Piping》2006
This paper presents the implementation concepts of a step length selection rule in a modified Hasofer-Lind and Rackwitz-Fiessler (HL–RF) method in order to improve its performance. Several step length selection rules in the context of structural reliability were studied and implemented in order to make the modified HL–RF method more robust and efficient. It has been demonstrated that a variant of Goldstein's rule, which is popularly known as the Armijo rule, is one of the most efficient step length selection rules. It is observed in this study that a proper step length selection rule will not only make the algorithm more robust but also improves the other parameters such as efficiency, capacity, etc. An iterative procedure, which enables systematic implementation into a computer program has been given. Several case studies have been taken from the literature to demonstrate and validate the proposed algorithm. A general-purpose software has been developed to solve a variety of structural reliability problems including those, which are complex and non-linear. In addition, non-normal distributions, such as lognormal, extreme value distributions, etc., are incorporated in this software. 相似文献
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In recent years the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. For example, in the power generation field, as thermal power generation occupied 60% of the power generation demand, considerable improvement of the thermal efficiency is required. This paper describes the pressure drop characteristics of finned tube banks used for heat exchangers in thermal power generation that were clarified by testing serrated finned tube banks with different fin heights for improved heat transfer and conventional spiral finned tube banks with different fin heights, and an equation to predict pressure drop which is necessary for the heat exchanger design is proposed. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(3): 179–193, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20112 相似文献
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