• 2022-07-23 问题

    长为[tex=0.357x1.0]5vVfAZliYwqMw8JaLE+iEA==[/tex]的均匀弦,两端[tex=1.857x1.0]sQ8UKBTHa4u9aJQTaFsBAg==[/tex]和[tex=1.714x1.0]z+3PraJ7SDoHa3jz672t+w==[/tex]固定,弦中张力为[tex=1.0x1.214]EsoJUyZj/6yD36MxA5tpQA==[/tex],在[tex=1.929x1.0]CE85dl2/W/1pUEtOAO/mFQ==[/tex]点,以横向力[tex=1.0x1.214]hzi2MsSHFnOjpdFGEAvoCA==[/tex]拉弦,达到稳定后放手任其自由振动.写出初始条件,问是否需要衔接条件?

    长为[tex=0.357x1.0]5vVfAZliYwqMw8JaLE+iEA==[/tex]的均匀弦,两端[tex=1.857x1.0]sQ8UKBTHa4u9aJQTaFsBAg==[/tex]和[tex=1.714x1.0]z+3PraJ7SDoHa3jz672t+w==[/tex]固定,弦中张力为[tex=1.0x1.214]EsoJUyZj/6yD36MxA5tpQA==[/tex],在[tex=1.929x1.0]CE85dl2/W/1pUEtOAO/mFQ==[/tex]点,以横向力[tex=1.0x1.214]hzi2MsSHFnOjpdFGEAvoCA==[/tex]拉弦,达到稳定后放手任其自由振动.写出初始条件,问是否需要衔接条件?

  • 2022-06-01 问题

    for i in range(b.max_row): for j in range(b.max_column): print(b.cell(row=i,column=j).value)上面语句运行的结果是:__________。 A: 1 1 1 1 1 1 1 1 1 1 B: 1111111111 C: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D: 出现异常

    for i in range(b.max_row): for j in range(b.max_column): print(b.cell(row=i,column=j).value)上面语句运行的结果是:__________。 A: 1 1 1 1 1 1 1 1 1 1 B: 1111111111 C: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D: 出现异常

  • 2021-04-14 问题

    【单选题】CDMA通信的基站,假定基站A的码片序列是+1 +1 +1 -1 -1 +1 -1 -1,基站发射bit为101时,实际发射的信号是 A. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 B. +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 +1 +1 +1 -1 -1 +1 -1 -1 C. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 D. –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1

    【单选题】CDMA通信的基站,假定基站A的码片序列是+1 +1 +1 -1 -1 +1 -1 -1,基站发射bit为101时,实际发射的信号是 A. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 B. +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 +1 +1 +1 -1 -1 +1 -1 -1 C. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 D. –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1

  • 2022-06-01 问题

    for i in range(1,11): for j in range(1,11): b.cell(row=i,column=j).value=1 #b是一个工作表对象for i in range(1,11): for j in range(1,11): print(b.cell(row=i,column=j).value,end=" ") print()上面程序代码运行的结果是()。 A: 1 B: 1 1 1 1 1 1 1 1 1 1 C: 1111111111 D: 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1

    for i in range(1,11): for j in range(1,11): b.cell(row=i,column=j).value=1 #b是一个工作表对象for i in range(1,11): for j in range(1,11): print(b.cell(row=i,column=j).value,end=" ") print()上面程序代码运行的结果是()。 A: 1 B: 1 1 1 1 1 1 1 1 1 1 C: 1111111111 D: 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1

  • 2022-10-25 问题

    下列哪个码片序列不能用于CDMA通信 A: ( -1 -1 -1 +1 +1 -1 +1 +1 ) B: ( -1 -1 +1 -1 +1 +1 +1 -1 ) C: ( -1 +1 -1 +1 +1 -1 -1 -1 ) D: ( -1 +1 -1 -1 -1 -1 +1 -1 )

    下列哪个码片序列不能用于CDMA通信 A: ( -1 -1 -1 +1 +1 -1 +1 +1 ) B: ( -1 -1 +1 -1 +1 +1 +1 -1 ) C: ( -1 +1 -1 +1 +1 -1 -1 -1 ) D: ( -1 +1 -1 -1 -1 -1 +1 -1 )

  • 2021-04-14 问题

    请仔细观察下面行列式的计算过程,如果四个等号都理解了,请选择A,否则请选择B。 | a 1 1 1 1 | |a+4 a+4 a+4 a+4 a+4| | 1 a 1 1 1 | | 1 a 1 1 1 | | 1 1 a 1 1 |= | 1 1 a 1 1 | | 1 1 1 a 1 | | 1 1 1 a 1 | | 1 1 1 1 a | | 1 1 1 1 a | | 1 1 1 1 1 | | 1 a 1 1 1 | =(a+4) | 1 1 a 1 1 | | 1 1 1 a 1 | | 1 1 1 1 a | | 1 1 1 1 1 | | 0 a–1 0 0 0 | =(a+4) | 0 0 a–1 0 0 | | 0 0 0 a–1 0 | | 0 0 0 0 a–1 | =(a+4)(a–1)^4

    请仔细观察下面行列式的计算过程,如果四个等号都理解了,请选择A,否则请选择B。 | a 1 1 1 1 | |a+4 a+4 a+4 a+4 a+4| | 1 a 1 1 1 | | 1 a 1 1 1 | | 1 1 a 1 1 |= | 1 1 a 1 1 | | 1 1 1 a 1 | | 1 1 1 a 1 | | 1 1 1 1 a | | 1 1 1 1 a | | 1 1 1 1 1 | | 1 a 1 1 1 | =(a+4) | 1 1 a 1 1 | | 1 1 1 a 1 | | 1 1 1 1 a | | 1 1 1 1 1 | | 0 a–1 0 0 0 | =(a+4) | 0 0 a–1 0 0 | | 0 0 0 a–1 0 | | 0 0 0 0 a–1 | =(a+4)(a–1)^4

  • 2021-04-14 问题

    共有4个站进行码分多址通信。4个站的码片序列为:a:(-1 -1 -1 +1 +1 -1 +1 +1) b:(-1 -1 +1 -1 +1 +1 +1 -1) c:(-1 +1 -1 +1 +1 +1 -1 -1) d:(-1 +1 -1 -1 -1 -1 +1 -1) 现收到这样的码片序列:(-1 +1 -3 +1 -1 -3 +1 +1),则( )发送1。

    共有4个站进行码分多址通信。4个站的码片序列为:a:(-1 -1 -1 +1 +1 -1 +1 +1) b:(-1 -1 +1 -1 +1 +1 +1 -1) c:(-1 +1 -1 +1 +1 +1 -1 -1) d:(-1 +1 -1 -1 -1 -1 +1 -1) 现收到这样的码片序列:(-1 +1 -3 +1 -1 -3 +1 +1),则( )发送1。

  • 2022-06-09 问题

    共有四个站进行CDMA通信,现收到这样的码片序列(-3 +1 -1 -1 +1 +1 +1 -3),则下列站点发送了数据1的是( ) A: (-1 -1 -1 +1 +1 -1 +1 +1) B: (-1 -1 +1 -1 +1 +1 +1 -1) C: (-1 +1 -1 +1 +1 +1 -1 -1) D: (-1 +1 -1 -1 -1 -1 +1 -1)

    共有四个站进行CDMA通信,现收到这样的码片序列(-3 +1 -1 -1 +1 +1 +1 -3),则下列站点发送了数据1的是( ) A: (-1 -1 -1 +1 +1 -1 +1 +1) B: (-1 -1 +1 -1 +1 +1 +1 -1) C: (-1 +1 -1 +1 +1 +1 -1 -1) D: (-1 +1 -1 -1 -1 -1 +1 -1)

  • 2022-06-09 问题

    共有四个站进行码分多址CDMA通信。四个站的码片序列为:A(-1 -1 -1 +1 +1 -1 +1 +1) , B(-1 -1 +1 -1 +1 +1 +1 -1) , C(-1 +1 -1 +1 +1 +1 -1 -1), D(-1 +1 -1 -1 -1 -1 +1 -1) , 现在收到这样的码片序列:(-1 -1 +1 +1 +3 +3 -1 -1 )

    共有四个站进行码分多址CDMA通信。四个站的码片序列为:A(-1 -1 -1 +1 +1 -1 +1 +1) , B(-1 -1 +1 -1 +1 +1 +1 -1) , C(-1 +1 -1 +1 +1 +1 -1 -1), D(-1 +1 -1 -1 -1 -1 +1 -1) , 现在收到这样的码片序列:(-1 -1 +1 +1 +3 +3 -1 -1 )

  • 2021-04-14 问题

    A、B、C三个站点采用CDMA技术进行通信,A、B要向C发送数据,设A的码片序列为+1,-1,-1,+1,+1,+1,+1,-1。则B可以选用的码片序列为: -1,+1,-1,+1,-1,+1,+1,+1|-1,+1,-1,+1,-1,+1,-1,+1|-1,+1,-1,-1,-1,+1,+1,+1|-1,-1,-1,+1,-1,+1,+1,+1

    A、B、C三个站点采用CDMA技术进行通信,A、B要向C发送数据,设A的码片序列为+1,-1,-1,+1,+1,+1,+1,-1。则B可以选用的码片序列为: -1,+1,-1,+1,-1,+1,+1,+1|-1,+1,-1,+1,-1,+1,-1,+1|-1,+1,-1,-1,-1,+1,+1,+1|-1,-1,-1,+1,-1,+1,+1,+1

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