發送短信 : Characteristics of pantograph-catenary arc under low air pressure and strong airflow

 __   _    __   __  __    __    ______    _____   
| || | ||  \ \\/ // \ \\ / //  /_   _//  / ____|| 
| '--' ||   \ ` //   \ \/ //    -| ||-  / //---`' 
| .--. ||    | ||     \  //     _| ||_  \ \\___   
|_|| |_||    |_||      \//     /_____//  \_____|| 
`-`  `-`     `-`'       `      `-----`    `----`