• 2021-04-14
    上图中阀2为( ),主要作用是防止油液回流,以保护液压泵安全。https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/9af153c05da643eba08f1927dea52ba0.jpg
  • 普通单向阀

    举一反三

    内容

    • 0

      线性谐振子的第一激发态的波函数为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/aab7a58985f443ed91a9f4036d4b56dd.png" />,其位置几率分布最大处为 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/44c963c6379540a099bfd79da6501b42.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/dff9139c15174797b8b68ef230d1ee90.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/ad088197932f430db9416ebf9d5b47fa.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/17949074010c4d44ad48b416055aaa86.png" />

    • 1

      在定温边界条件下,稳态、无内热源、导热系数为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/bf35cea9e03449f0b64673e21dbdde56.png" />、内外径分别为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/3323de11627a4f51bc7b1fff540dcfef.png" />和<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/675dd37c97db44a7a723838858eab505.png" />、长度为l的单层圆筒壁的导热热阻为()。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/892cb3300ea148d994377392a697acb0.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7003425fa14a44d5aadbb9040240edca.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/040ff55c3a244877a0b06faf6042f47a.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/b5d2a5ed4d644ae6b2dab35d2ed8f3e5.png" />

    • 2

      如图示并联管路,已知各支路的沿程阻力系数之比为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/6e209020d20f4543823ce6516ae8ca06.png" />,管长之比为<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/50814fe028094040bc955d8e1542b6d2.png" />,且<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/40b4c6a9565b483590c5c7d607e7ed66.png" />,则两支管的流量之比<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/1055534bfce6426a94682ba086a5b17e.png" />=()。<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/77815369f5cd41f3a2e68b9524b454c5.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/0cd231eebe45465f941a0f614743e6d2.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7555afa5223e40bf89ca575cf7b52754.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/1b06cd474b844644a6d97ad87d208e94.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/d0b2bca045414236a7d1c9925a9264f2.png" />

    • 3

      如图所示,离心机通风机借集流器从大气中吸入空气。若插入盛水容器的玻璃管中的水上升高度为h,则通风机流量<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/b90be52d519d4880a560e59df52dd29c.png" />=()。<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/dca2260bbd5c4051b28bbb87ae1d6de9.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7b4225635cfe41e28af202418785be8d.png" border="0" vspace="0" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/05404534275442c597194a44ee9f46f7.png" border="0" vspace="0" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/5509cc1799e54c64a7a11a7f37417710.png" border="0" vspace="0" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/307ded8ddb2c486d935b6bc79faa7688.png" border="0" vspace="0" />

    • 4

      电路如图所示。则u01、u0与 uI的运算关系分别为( )、( )。 <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/418adfb996644706aef30b7d2841ccb9.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/ffe4934c2b0748428937c24c7ff16c3b.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/1da45f59ab0845f7be8cdc1f80a78caa.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/ca685a45d5764329b8551eb6eaeb6a58.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/d3f91ade92954e7fbd65a917b04cc13b.png" />