下列MATLAB命令中是求矩阵A的<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/f6ca9c0d5f0947baa86708ea8c85432a.png" />-范数的命令的是( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/75a9a2298d884620a7af2395a55756c0.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/c962dc7876c146788335b14ba11be7c7.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/834b2661896f4c4c9dbb287005a486df.png" /> D: 其他都不对

延时环节<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/5c7e2dbac7e649e9ba2da3656a964d45.png" />，其相频特性和幅频特性的变化规律是（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/0831ed5bb7a5495b9632eb9be36d703d.png" /> dB B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/a2358c63853d4f50a2cf9003407f588f.png" /> dB C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/23119fba416f46db820927d5fcd66a7d.png" /> dB D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/67d0e95b64db43bd9c955f6cf62e36a2.png" /> dB

下列不属于弹性力学平面问题的是（ ）。 A: 应力分量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/14e55ab2cde14d22a44bff9ea88507d2.png">，只有应力分量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/c3c1da2ca4e64ad19e0fbc1764ed6bcc.png">存在，且它们都仅为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/7bffc15d98b240c584d659d1aa155670.png">和<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/dbee1ba1e52447b2bb076c7d812d3e5c.png">的函数 B: 应变分量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/ea8a2b953bca4b598b6781db39c5f5bf.png">，只有应变分量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/7877a5c9731d4b54b054875be6f3ea05.png">存在，且它们都仅为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/7bffc15d98b240c584d659d1aa155670.png">和<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/dbee1ba1e52447b2bb076c7d812d3e5c.png">的函数 C: 位移分量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/1e6aeef29fa74143bf306acfc598d7e4.png">，只有位移分量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/0a59276fcf7e48d8bc4d1fb7313cc78d.png">存在，且它们都仅为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/7bffc15d98b240c584d659d1aa155670.png">和<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/dbee1ba1e52447b2bb076c7d812d3e5c.png">的函数 D: 薄板弯曲问题

坐标系{B}相对于坐标系{A}绕Z轴旋转<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/0e7f1303cace4a9fa888211d1b94e3c3.png" />度，坐标系{B}中的矢量<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/06f5b17a51fb43deb2e94fe685b5b511.png" />在{A}中的坐标表示为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/86783ba498314fdfa0c22abffc2891f2.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/ea644ea443b74b54b41c89eff9db781a.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/dddcfd36e178435c8a82f63cc982fd2b.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/1d5f3187c48f447eb117b0005e7ca646.png" />

下列重氮离子进行偶联反应，哪个活性最大？（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/971f9e07d154479180dc4b963ca9f331.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/9bd8814746a84f9c81f49eefa5104a05.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/936cd022f8df4a38abe5e1adaa8e97ad.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/42005484f8fb4b1eac7615c0f6a9d46d.png">