發送短信

數:

提供者:

CAPTCHA:

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

Please enter what you see:

發送短信 : Delay SIR model with nonlinear incident rate and varying total population