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建立了由钢铝复合轨、绝缘支架、支撑卡爪和支架底座组成的三轨系统的有限元模型,计算了其动力特性,分析了下部桥梁结构振动的影响,为轨道的磨耗磨损研究及集电靴与接触轨的动态受流仿真的进一步研究建立基础。研究得出,三轨系统前十阶的自振频率范围与桥梁结构的自振频率相差较大,两者不会发生共振。 相似文献
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以级联型高压变频器(CAS-HVI)系统拓扑结构及功率单元结构为对象,通过Simulink构建功率单元组、移相变压器系统以及基于载波移相SPWM(CPS-SPWM)调制原理的PWM发生器子系统,形成基于VVVF控制的CAS-HVI仿真平台。利用该平台分别对突加减负载时功率单元的输入电流、母线电压、母线电流、输出电流的变化进行定性分析,并对相间短路极端故障情况下的功率单元状态进行定性分析。该仿真平台不但能提高CAS-HVI系统的开发安全性以及开发效率,有效降低开发成本,同时也展示了仿真的高效性及便利性。 相似文献
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李林 《铁路通信信号工程技术》2010,7(6):76-77
从维护和管理的角度出发,对影响蓄电池寿命的因素进行了分析,对如何提高电池的使用寿命进行了探讨,并根据日常的一些维护经验,对蓄电池的维护提出了建议。 相似文献
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目的防控铁路甲型H1N1流感疫情传播,为规范有序地开展应急接种提供依据。方法按照知情同意、自愿、免费的原则,有计划分步对武汉铁路重点人群实施应急接种。结果共接种12 599人,接种率达89.76%,其中列车员接种9 020人,接种率达到92.79%,占总接种人数的71.59%;AEFI发生率为零,一般性不良反应发生12例,发生率为9.52/万。结论在铁路重点人群中进行甲型H1N1流感疫苗应急接种,安全可行,是防控甲型H1N1流感疫情的有效手段。 相似文献
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文章首先对HXD1型机车辅助开关柜SKS3模块接线脱落的故障类别和故障原因从人、机、料、法、环、测等方面进行了分析,在此基础排除非主要因素,然后通过DOE的方法找出几个影响辅助开关柜SKS3模块接线脱落的重要因子。通过质量改进,标准化生产加工工序,以减少以后生产中SKS3模块接线脱落。 相似文献
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一种基于通行信号链的列车运行控制移动闭塞系统(SCBTC-MAS),可作为一个独立监测系统与现有列车运行控制系统(TBTC或CBTC)并联运行,为列车运行提供一个"双保险"机制。SCBTC-MAS具有精确、实时的轨道占用检测及闭塞控制能力,令列车在信号系统故障、列车定位失效、人为操作错误情况下,仍可有效避免相撞事故的发生。 相似文献
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The High Line is an elevated public park in New York City, transformed from an unused freight rail line. Pedestrians walking through Manhattan’s West Side can walk either on the High Line or on a footpath below. Using Manhattan as a laboratory, this paper offers a combined assessment of noise and particulate matter pollution for its pedestrians. Noise and PM2.5 levels were recorded simultaneously for two cases (i) pedestrians walking on a footpath alongside road traffic and (ii) pedestrians walking on the elevated High Line. Testing took places over three days in autumn 2014. Results were analysed to investigate if pedestrians using the High Line would have a lower pollution exposure to those using the footpath below. Results showed statistically significant differences between the upper and lower levels in exposure to both pollution types. In order to quantify the overall impact, results are expressed through a combined air–noise pollution index. This index indicates that the average reduction in PM2.5 and noise pollution along the High Line compared to the footpath below is approximately 37%. 相似文献
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The emission of particulate matter (PM) and other atmospheric pollutants in port operations and shipping have caused a huge negative impact on the environment. Consequently, how to evaluate the environmental efficiency of ports and put forward corresponding countermeasures on this basis is becoming a more important issue than ever before from the perspectives of the government, academia, and society. We construct three data envelopment analysis (DEA) models to evaluate the environmental efficiency of ports under the circumstances of environmental control, non-environmental control and PM emission through inter-ports cooperation. The innovation of the DEA models constructed in this paper lies in: (1) Setting environmental control parameters to uniformly manipulate the situations of environmental control and non-environmental control, etc.; (2) Allowing non-equal proportional change of input index, expected output and non-expected output index; (3) Setting preference coefficients for ports to admit favorable decisions; (4) Providing a distance formula of expected output for PM emission reallocation. Further, data from 11 major ports in China are collected to compare the expected output under different PM emission standards assuming the situation of environmental control and non-environmental control, port cooperation, and non-cooperative sewage discharge. The empirical results show that: (1) Ports in the eastern China (Shanghai, Ningbo, and Nanjing) have higher port efficiency; (2) Port cooperation can improve the overall expected output but it will lose its edge with the improvement of PM emission standards. (3) Ports follow the same trend of output loss regardless of favorable decisions. In the end, the author makes a summary, puts forward relevant policy suggestions and makes the recommendation for future research. 相似文献