• 2022-06-19
    已知信号的最高频率分量为 Hz,若抽样频率,则抽样后信号的频谱一定混叠。( )
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    • 0

      试求序列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/cb5683e4401b464bb94af075183c06d2.png" />的双边z变换及其收敛域( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/07475602a8b04ef18fe697ba033d87cc.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/9d0ea6592c7d45a28bb6dac86e53ca52.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/d594b5541bf8465d9eca5af4a3b38545.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/ddd3f7717f134d54a0e27eef90e3b930.png" />

    • 1

      下列化合物存在顺反异构的是( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/f14204f643814b84bf651ec9404a27d2.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/2960cc15743342ba8415b73975674596.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/f4313a484dbc4c14867fee1d1d3845d8.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/b848dd83a35c43d4acca3b558de80d36.png" />

    • 2

      下列结构具有对称面的是( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/67f372abc1e54070b6805d653dfb19a0.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/0e819dd6086b43dc821e450310bf3bdd.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/47aae3d232074cdfa8615b322c5fceb9.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/960811b669074305a30d03f0ab617e88.png" />

    • 3

      下列分布函数性质的叙述中错误的是( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/aa7be662728549808e1e31a941f40586.png" />是右连续函数,即<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/3d2dd341bbb34bc49c6c16a0648e73a0.png" />; B: 对任意一个实数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/6af90c1b0d1a4a2e9f52db02fba49eb3.png" />,都有<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/76a52406d5984c29b26b56770cd45589.png" />. C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/700eb5d94c754071b3fabc46105a97e5.png" />,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/15b2abeddbab4e798304b38ed7d0a073.png" />; D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/25cc87b8d99c4475861371e994a4a857.png" />是<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/b62c2e7b67af45a28d3b1d079dd4ffd0.png" />单调非减函数;

    • 4

      梅森公式的正确表达形式为( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/32780db6b4c34c3597992c3b7abf0732.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/5cc2dc9acb204d79a246fd1b76b4a91b.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/bf8a7fc9338f4d19b481d8b3334c37f6.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/0ffb1fb6223642fe8d12dd5e1e663af5.png" />