Diodes are electronic devices which rectify alternatingcurrent to direct current.
二极管是将交流电整流成直流电的电子装置。
2
The disadvantage is that reverse electrodialysis produces directcurrent, whereas the world runs mostly on alternating current.
不足处是反向电渗析产生的是直流电，而世界上主要使用交流电。
3
The system generates a directcurrent, so using it to power DC devices locally is more efficient than switching to the alternating current needed to feed it back to the grid.