博客迁移后的第一篇博文

test markdown

puts("Hello World!");

test mathjax

$$e^{ix}=\cos(x)+i\sin(x)$$ $$H=-\sum_{i=1}^N (\sigma_{i}^x \sigma_{i+1}^x+g \sigma_{i}^z)$$ $$f(n) = \begin{cases} \frac{n}{2}, & \text{if } n\text{ is even} \\ 3n+1, & \text{if } n\text{ is odd} \end{cases}$$ $$\lim _{ x\rightarrow \infty }{ \sum _{ k=1 }^{ x }{ \frac { \sin { k } +\cos { k } }{ k } } }$$ $$\begin{aligned} a_1+a_2 & = a_3 \\ b_1 & = b_2+b_3 \end{aligned}$$ $$a\bmod b,a\pmod b$$