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

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">

Matlab命令A=magic(3)创建一个3阶魔方矩阵，求A的特征值的绝对值的最小值用（ ）. A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/d605a0a8e560440081a209fc0da04637.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/e36ed713fb2e481ab69ecd158317c17e.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/6cd6fb595e6d45fd962a01d8b6ac10f5.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/64c2c88e6099475dbacd7e6d12841129.png" />

JK触发器的特性方程是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/9dfa6d2bcd9d459ca40130783da2454a.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/1b99630eead9460aa41cd8b7e0a19594.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202102/5868e29bb93b4f9eb7adc83586f47786.png" />