N =2500, n = 400.x = 3000 kg; sx = 300;1 -二-95%, Z :./2 = 1.96(1( )
N =2500, n = 400.x = 3000 kg; sx = 300;1 -二-95%, Z :./2 = 1.96(1( )
发布时间:2025-07-08 08:13:10
N =2500, n = 400.x = 3000 kg; sx = 300;1 -二-95%, Z :./2 = 1.96(1( )