The foundation of automatic block and cab signal is track circuit.
自动闭塞和机车信号的基础是轨道电路.
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Study on Simulation of Train Fleeting Operationwith Automatic Block System.
运行调整系统若干技术难点问题的研究.
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Automatic block signals and other means of communication enable railroads to operate safely.
自动停车信号及其它通信方式使铁路得以安全运行.
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