## Archive of posts on Feb 3, 2023

### 手纸本

何为

*手纸本*?- Categories: literature
- Tags: from zhihu, literary composition, short story, chinese

### Introducing bra–ket notation to math learners

Bra–ket notation is a good-looking notation! I am sad that it is not generally taught in math courses. Let me introduce it to you.

- Categories: math
- Tags: from zhihu, quantum mechanics