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782.
供电牵引网运行方式多种多样,在常规的单线、复线供电方式中,传统的电抗法、电流比法在实际应用中均能满足要求。对于全并联直接供电牵引网短路故障,采用两相对称分量法,分析电路特征,得到短路阻抗表达式。根据阻抗表达式绘出电抗距离曲线图,证明全并联直接供电牵引网短路时,故障点仍然可以采用电抗查表法进行定位。 相似文献
783.
Sloshing phenomenon in the liquid cargo carriers has caught the attention of researchers as the interaction between the sloshing
waves and structure is one of the key point and difficulty in the study of sloshing. In this paper, we captured the free surface
with a volume of fluid (VOF) method and then calculated the motions and responses of the structure by adopting the Reynolds-averaged
Navier-Stokes (RANS) equations for the whole fluid domain. With the use of user defined functions (UDF) in Fluent, the interaction
between fluid and structure was then simulated. As a reasonable simplification, the authors studied the response of a single
cantilever in a tank under sloshing loads; Further study should pay more attention to the mechanisms of interaction between
sloshing waves and elastic structures. 相似文献
784.
SiC颗粒增强铝基复合材料的宏观力学行为与其微观损伤机理密切相关,随温度的升高,材料力学性能明显下降,SiCD/A356复合材料表现出不同的细观损伤机理.文中对真空双搅拌方法制备的质量分数为20%的SiC颗粒增强铝基复合材料在室温和高温下的细观损伤机制进行了研究,在试样断口上,通过扫描电镜观察到了不同的裂纹萌生和扩展机制,根据不同温度下表现出的不同失效方法,归纳出了复合材料细观损伤的温度效应曲线.研究表明,在室温下复合材料的裂纹萌生以基体撕裂和颗粒断裂为主,高温下其裂纹萌生机制以颗粒脱离和基体撕裂为主. 相似文献
785.
根据钢和混凝土的应力应变关系,提出该组合梁考虑钢与混凝土界面相对滑移的力学性能分析方法,并由此编制计算分析程序,求解竖向集中荷载作用下组合梁的承载力、荷载-挠度曲线以及钢与混凝土的相对滑移分布,并通过与试验对比,表明按该文分析方法得出的结论与试验吻合较好。 相似文献
786.
787.
介绍了一种被动雷达系统测向处理机的设计,阐述了该侧向处理机的总体设计思想、系统组成和工作流程,对设计中的关键技术和实现方法进行了深入的研究,系统采用了DSP和FPGA硬件结构[1],具有集成度高可靠性好的特点,该测向处理机的工程应用可对雷达系统设备稳定、技术指标提升起到重要作用。 相似文献
788.
Since the Taiwan High Speed Rail operations, Taiwan's transportation market entered into a new era. Because of its competitive service of speed, convenience, environmental concerns and comfort, the High Speed Rail has not only made significant changes but has played a significant role in Taiwan's transportation. However, Taiwan now is an aging society. Due to the physical constraints among the elderly, demands to redesign the traffic system and maintain transportation safety are essential considerations. In the current market, Taiwan's transportation construction is facing fewer barriers; however, it must still improve, especially considering the health of the elderly. Thus, this study investigates elderly passengers' demands and further examined the relationships among service quality, corporate image, customer satisfaction, and behavioral intention. According to empirical analytical results based on structural equation modeling (N = 341), satisfaction directly affected travel behaviors, while service quality and corporate image played indirect roles. In addition, service quality plays a significant role on the effect of satisfaction. This study provides empirical evidence to indicate the quality of the accessible environment affects not only the effectiveness and efficiency of service quality, but also, the corporate image. The results provide valuable references for critically managing the elderly's usage of the high speed rail transportation service. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
789.
Abstract Malaysia is one of the few countries in the world that provides a fuel subsidy to consumers. Due to the recent economic crisis, the Malaysian Government decided to revise its fuel subsidization policy from a fixed price subsidy to a floating price subsidy dependent on global oil demand. Recognizing that the change in fuel subsidization policy can have an impact on travel behavior, this article investigates the short-term impact of the policy change on private and public transportation in the Klang Valley region of Malaysia. Spectral analyses are performed to investigate if the policy change has an impact on private vehicle travel demand, measured in terms of road traffic, and short-term travel demand elasticity with respect to fuel price is estimated. To measure the impact on the public transportation system, the demand cross-elasticity values of rail transit and buses are also estimated. It was found that traffic flow reduces with an increase in fuel price, although elasticity and cross-elasticity values obtained are low. The article finds that there is a potential mode shift from private vehicles to rail transit with increasing fuel price. It is demonstrated that reducing fuel price subsidy can be an effective travel demand management strategy to alleviate congestion. 相似文献
790.