A railway monitoring system firstly includes an optical fiber. A first part of the fiber is attachable to one of a pair of tracks of a rail, and a characteristic of the first part of the fiber is variable in correspondence to variance of a characteristic of said one track where the first part of fib.....
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The utility model provides a caution board including a rating plate, a luminous caution device, an acoustic caution device and a caution control unit. The utility model has the advantages that the caution board with an audible-visual device has a simple structure, and is easy to identify and availab.....
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The invention provides a side emitting light emitting diode light source within the lens. Its role is to change the light emitting diode chip emitting direction, most of the light from the side of the light emitting diode chip along the central vertical axis of the very small angle inward gathered a.....
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Disclosed is an extendible emergency bump guard post arranged underground comprising a base with open top, a post placed in the base not in use and in vertical place in use and a protecting hood movably connected with one end of the base, wherein when the post is located in the vertical or horizonta.....
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一种用于三轴试验的自动和连续地测定土样受压时体积改变的装置，包括一个具有柔韧橡胶膜壁的容器１３，土样１０装在所述容器内。在样品上加上一个载荷排出样品中空气和水分。在样品受压过程中，通过将水泵进或泵出内腔１９０来测量受压样品的体积改变量。
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