体心立方结构金属晶体的的密排面为（ ）， 密排面晶面间距为（ ）。 A: （110） B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/b9f806bad3874ceca9c758a3b0107652.png"> C: （111） D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/80eebcaaf36e4af084acf1e4d07e1acf.png"> E: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/dc64bdb4cb04403097873133316c57a8.png"> F: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/1b1c162777d04e51bd02eb8f92094b84.png">

在圆柱壳轴对称弯曲问题的基本方程中，有三个方程式自动满足的，我们只需要求解三个平衡方程，它们是： A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/3c3eb06997f449be89a76e35f8073f1f.png"> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/7c87e3a7dc5445688a702fe5364a8635.png"> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/c6739033a3da46ce92e809ea34907621.png"> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/55a259aaa0b842c99f0d9c3b9176cae3.png">

已知f(t)↔F(w)，则下列说法正确的是（） A: tf(t)↔wF(w) B: F(t)↔f(w) C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/e987a05c70d3455bad2fbdef6ce1fc1d.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/92f68075a5ff43708660199e4eed9415.png" />

逻辑函数F(A,B,C)=AB+BC+AC的卡诺图为（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/7a8254757f8a4fc6ab82fa93a8e86ebf.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/229cbcade3654fb99c66a7c102ec046f.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/1c851f1288be499c92d2a7b40607bd1a.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201809/3b385269839a45df9645db71096c2e81.png" />

下图关于纯度对比 9 调图， 7 、８、９对比表述为（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/c32fd0952fa5446b8bdeaf1c18602ecd.png