A rail road freight car truck has a truck bolster and a pair of side frames, the truck bolster being mounted transversely relative to the side frames. A saloon has a transparent front extending upwardly from the forward section with sides extending upwardly from the rearward sections and a roof coupling the front and sides at an elevated location. The method promotes the transmission rate and the anti-interference ability and advances the spectrum efficiency. The detector also includes an amplifier. The one or more oxide layers can have compressive stress, the one or more nitride layers can have tensile stress, and the oxide and nitride layers could collectively have compressive stress.