您要查找的是不是：
- polarity directional relay 极化方向继电器
- Recently, a new protection technique is developed based on the time graded overcurrent directional relay [1]. 最近，一种新的保护技术是发展的基础上，时间梯度过压继电器方向继电器[1]。
- This paper has explained the manufacture principle of Al-flux-cored welding wire, and studied the technical characteristics of Aluminium alloy welding with straight polarity direct current TIG method. 阐述了药芯铝焊丝的制造原理,研究了TIG直流正接焊接铝合金的工艺特点。
- reversed polarity direct current 反接直流
- induction disc type directional relay 感应圆盘式定向继电器
- The two systems of government are polar opposites. 这两种政体正好相反。
- induction type power directional relay 感应式功率定向继电器
- electronic valve type power directional relay 电子管功率定向继电器,电子管式功率定向继电器
- voltage drop compensation directional relay 压降补偿式定向继电器
- induction-type power directional relay 感应式功率定向继电器
- electronic valve-type power directional relay 电子管式功率定向继电器
- induction disc-type directional relay 感应圆盘式定向继电器
- Most insect do not live in polar region. 大多数的昆虫不在极地地区生存。
- voltage and power directional relay 电压和功率定向继电器
- Protection for these isolated systems has been a relatively simple task, which is carried out using over current directional relays with selectivity. 采用具有选择性的过电流方向继电器,对这种相互分隔直流系统的保护相对就简单。
- three-phase power directional relay 三相功率方向继电器
- Are there any animals in the polar circles? 南极圈和北极圈内有动物存在吗？
- ON THE TEST OF DIRECT RELAY OF PROGRAMMES FROM CCTV 直接转播中央电视台节目的试验研究
- Located or found in one of the Polar Regions. 环极的，围绕极地的位于或发现于一个极地区域中的
