news high-speed rail bogie shock absorber block tri(dimethylaminopropyl)amine cas 33329-35-0 high-frequency vibration attenuation system high-speed iron bogie shock absorber block tri(dimethylaminopropyl)amine cas 33329-35-0 high-frequen... 03/2072High-speed rail bogie shock absorber block tri(dimethylaminopropyl)amine CAS 33329-35-0 high-frequency vibration attenuation system