Feb 19, 2015 · It's an abbreviation of quod erat demonstrandum, which is the Latin translation of a Greek phrase meaning "which had to be proven". To the ancient Greeks, a proof wasn't …

量子电动力学（QED，Quantum Electrodynamics） 是描述电磁相互作用的理论，可以说是目前为止最为精确的理论了。 在量子力学提出之后（主要标志为1926年薛定谔提出薛定谔方程）， …

(also written QED and QED) is an initialism of the Latin phrase quod erat demonstrandum, meaning "what was to be demonstrated", or, less formally, "thus it has been demonstrated".

知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见解，找到自己的解答」为品牌使命。知乎凭借认真、专业 …

众所周知 Q.E.D. 是quite easily done的缩写 挥挥洒洒地终结证明，不经意间注记quite easily done，大佬的高考，往往就是这么朴实无华，且枯燥 而阅卷老师只会在佩服之余，点下满分 …

May 31, 2019 · QED is short for the Latin phrase quod erat demonstrandum and means, loosely, "that which was to be shown". As noted in the comments, it's a summary way of saying that …

Apr 21, 2017 · 0 I had always used QED (quod erat demonstrandum) at the end of a proof until I was introduced to using Halmos' symbol. Since it was a 4-sided symbol, my mind has always …

原文如下 西江月・证明 即得易见平凡，仿照上例显然。留作习题答案略，读者自证不难。 反之亦然同理，推论自然成立。略去过程Q.E.D.，由上可知证毕。 显示全部

量子电动力学（QED）存在缺陷吗？ QED被认为是物理学中最成功的理论，其理论预测与实验数据高度符合。 既然如此，为什么一些电磁现象至今也没有好的理论解释？ 比如石墨烯的超导 …

这导致电子在吸收光子被加速的同时也会出现发射光子被减速的过程，那么这个时候，我们将预期电子既不会加速e 也不会被减速，能量转移量为零，即 \Delta E_ {QED}=0 。 天啊，这怎么回 …