• 2021-04-14
    图示为纺织机中的差动轮系,设z1=30, z2=25, z3=z4=24, z5=18, z6=121, n1=48~200r/min, nH=316r/min, 求n6=?http://edu-image.nosdn.127.net/4C1BAD9800F0F83109C2DD944746C87B.png?imageView&thumbnail=890x0&quality=100
  • 268.14~295.29
    本题目来自[网课答案]本页地址:https://www.wkda.cn/ask/ezaxaxjtmajaxoo.html

    内容

    • 0

      设????????z[n],????=0,1,⋯,????−1n=0,1,⋯,N-1为0,????[0,θ]上均匀分布的随机变量且相互独立,则????θ的最大似然估计为: A: (1/N) ∑z[n] B: min????????????min z[n] C: max????????????max z[n] D: (12[max????????????+min????????????]1/2){max z[n]+min z[n]}

    • 1

      判断下列关系模式可以达到的范式级别:1)R(X,Y,Z)F={XY→Z}2)R(X,Y,Z)F={Y→Z,XZ→Y}3)R(X,Y,Z)F={Y→Z,Y→X,X→YZ}4)R(X,Y,Z)F={X→Y,X→Z}

    • 2

      调用下面函数,错误的是( )。def f(x, y = 0, z = 0): pass #空语句,定义空函数体 A: f(z = 3, x = 1, y = 2) B: f(1, x = 1, z = 3) C: f(1, y = 2, z = 3) D: f(1, z = 3)

    • 3

      执行下面代码,错误的是‪‬‬‬‬‬‬‬‬‬def f(x, y = 0, z = 0): pass # 空语句,定义空函数体 A: f(1, x = 1, z = 3) B: f(z = 3, x = 1, y = 2) C: f(1, z = 3) D: f(1, y = 2, z = 3)

    • 4

      选择符号填空(A:"∈", B:"∉")。(1)0 N;(2) 0.6 Z;(3)π R;(4)1/3 Q;(5)0 ∅