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;

已知某系统的数学模型为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/36eb028cda9447468911e236a321722e.png" />，那么系统的沖激响应<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/2a6ea359e85c408fbece93c2e81f6076.png" />为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/2c5c40b2c9f84205812addf9df60664b.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/d1350a891d364096858a5f83a7415ece.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/e1352972cbd24aacb663ce6ef7fc95fc.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/1c91057ec86848a1b761ccb26b3ed883.png" />

求序列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/5131160157fe4bc7bd53878104ffd1cd.png" />的DTFT为（ ） A: 不存在 B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/e521d6f23d234b38b3ad34622a74b1b2.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/fbec0bedcb3c47a8825ec337b818764f.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/5fc107dac73e4c00afcf8f1701f80a47.png" />

下列表达正确的热力学方程有（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/4e8abe7a4904459cb6994188d5d122af.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/434c7862e21a4543b52489df5d34f858.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/081b9e9ece6a4bc49c1950b4e28cf479.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/91785cd2f0d04bddb91adb687ce55f2a.png" />

已知信号<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/dd73dc4df2f24b0780af6a97fdf8a562.png" />的奈奎斯特角频率为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/a43212a9536a46ac8a20c6dc7d78906d.png" />，则信号<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/1821f6e23ad74b4ca7d8fb212ee4dada.png" />的奈奎斯特角频率为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/9eb48130d0e24c1c8234e1de4c730c0f.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/db0c7b373ae04e0599630a5086233c04.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/353ea3d067db4076977d456717aa82d2.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/6d550ebc083244648d78d5b2c334dfce.png" />