DCLn.直接藕合逻辑线路dcabbr.直流(=direct current)abbr.哥伦比亚特区(=District of Columbia)dc dc converter直流一直流变换器DC cancellation直流消除DC plus AC bias交流重叠偏置DC-modulation直流调制dc noise margin直流噪声容限DC ground fault直流接地DC power switch直流开关电源DC quick switch直流快速开关DC motor design电机设计DC high voltage直流高压