• 2022-07-25
    下列结构中同时存在p–π 共轭和π-π共轭的是( )。
    A:
    B:
    C:
    D:
  • D

    举一反三

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    • 0

      下列化合物中,能发生酰化反应的是( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/517de8a8f42942cf82859d6d49f675cf.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/6c8d89865ee24be78747d6fd25cd2d71.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/2483bc407db748cc96889b6112cbfb5c.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/cb06682ded43441d80d66a15e803c3b8.png" />

    • 1

      自然指数衰减函数e-at的拉氏变换为( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/8737eea8f9ab4b57956966b78c81457a.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/e2e3d66540944a6abef22331e994afd3.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/d1f05087cb5641e59f6be5245adf2af2.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/333ade86887d4e3aa44332086c758e09.png" />

    • 2

      某时刻进程的资源使用情况如下表所示,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/21691db0015943d6b7e82451ed230996.png" />此时的安全序列是( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/54b17f5e49fa4900a7ca6f50aedc8af4.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/a5ce7b0da26e4b608ebb5332681915bb.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/7c94f93470f44814a1e8ee30e9af9f76.png" /> D: 不存在

    • 3

      在pH=10的氨缓冲溶液中,用EDTA滴定Zn2+到计量点时,以下关系正确的是( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/852002b099fd4027b25bdb1888420153.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/8479def4b7d84391ac16a08271fc834f.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/fca6acf6d6b64cb2ba4f603e56ff3d7d.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/7dc96d321d5e4fd799be3062f25a3930.png" />

    • 4

      可以研究催化剂的物相结构的表征技术有( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/4b0222481c464b22951f8ab3ef826c65.png"/> B: 程序升温脱附(TPD) C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/541eea97faef4823a2e605fa89bf5732.png"/> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202109/848d3b1db944457da2462fb6381e3779.png"/>