假设面心立方晶体的晶胞参数为a，则（111）面的原子密度为（ ）。
A:
B:
C:
D:
A:
B:
C:
D:
举一反三
- 已知串联支路为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/65b91bc067d14873a38d0c4675b53329.png"/> ， ，则其传递函数为（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/8bc361d7b437451dac5c0c42c3213311.png"/> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/7db9751653e24eba9f152b6937c8c256.png"/> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/a4b7ab7e122b40068ce6b78635486bae.png"/> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/a6b34e5a8a764d5c9b78c725d7b77ed4.png"/>
- 已知<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/43114282e941476ba93775909fb3f237.png"/>，用拉氏变换法求解微分方程<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/0db291610cb64fa8ad46ae0bd15476b0.png"/> 的结果为（ ） A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/29ff68f02bdd438bb2e16c2a6e1ec18b.png"/> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/0010c1593c9145a4b928548ab38cf426.png"/> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/1f562f2536584121b53c30e4db08df88.png"/> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/f593399cb630435192baa8b3e871b533.png"/>
- 已知系统和初始条件<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/15eb73651c0a4ae094e6de902b6c21ca.png" />求初始状态激励的响应 ( )。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/d016acd038b04b699e76c2354357c3d2.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/7a10be8f1ce74599a610fd0b9b9eb195.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/4621f442538946fdb897b89a1461e1e1.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/61b797beffc74a99b91e1934af1372fb.png" />
- 已知下列传递函数<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/52a69b746f6d4543a289093c286ea763.png" />则是其能控规范形实现的为（）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/5cbf894bf07b4884bd0e9a8339005832.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/063b93d5e1794cc7b2e0854e9c8d16e1.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/b02c120bde7746a68c1d324058f99bec.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/48b05a371844434b84dfa6dbae612c74.png" />
- 下面哪个图形是分流阀的图形符号： A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/4a427ac6ca3a451d88b23ac3bd534502.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/bef6c57a0c1c4d6bbfc50082f7edfe14.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/750259c8aa1c4efdb338873df39ffe24.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/5d511af88d8349f1bcf5e8ae6d7b1d09.png" />