The non-zero dispersion shifted single-mode fiber, also known as ( ) fiber, is a new type of fiber designed and manufactured to adapt to the WDM transmission system.
【简答题】润扬长江大桥是我国第一座由悬索桥和斜拉桥构成的组合型特大桥梁,其北汊桥为斜拉桥,它是利用一组组钢索,把桥面重力传递到两侧的高塔上.如图,A 1 B 1 、A 2 B 2 、A 3 B 3 、A 4 B 4 是斜拉桥上4条互相平行的钢索,并且A 1 A 2 =A 2 A 3 =A 3 A 4 ,B 1 B 2 =B 2 B 3 =B 3 B 4 ,如果钢索A 2 B 2 =70米,钢索A 4 B 4...