焊缝坡口钝边

The results show that laser-arc welding can achieve full penetration by single-path butt jointing through appropriate parameters; Y shape groove with 8 mm truncated edge can enhance the penetration ability of laser-arc hybrid welding. Low welding speed is good for penetration, however the limitation still exists for hick plates joint. Gap is significant factor of penetration when work pieces is large thickness. The hardness of thick plates joint shows that there is big difference in mold of vertical thermal cycle using laser-arc hybrid welding.

结果表明：通过激光功率等焊接规范匹配，激光-电弧复合焊接能实现20 mm厚板的全熔透单道对接；钝边为8 mm的Y形坡口有助于提高厚板激光-电弧复合焊缝熔透能力；降低焊接速度有利于提高熔深能力；工件厚度较大时，装配间隙对焊缝熔深能力的影响较为显著；接头硬度表明厚板激光复合焊焊缝纵向热循环模式存在较大差异。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。