[{"title":"( 3 个子文件 41.71MB ) 信号与系统.zip","children":[{"title":"信号与系统(第三版)(上册).pdf <span style='color:#111;'> 14.58MB </span>","children":null,"spread":false},{"title":"信号与系统(第三版)(下册).pdf <span style='color:#111;'> 12.12MB </span>","children":null,"spread":false},{"title":"信号与系统(第二版)(完整版本).pdf <span style='color:#111;'> 17.76MB </span>","children":null,"spread":false}],"spread":true}]