\begin{displaymath}
\left\{
\begin{array}{l}
\frac{\mathrm{d}S}{\mathrm{d}t}=-(kI+k_{0}Q)S\\ \\
\frac{\mathrm{d}I}{\mathrm{d}t}=(kI+k_{0}Q)S-(\alpha+h_{1}+\delta_{1})I\\ \\
\frac{\mathrm{d}Q}{\mathrm{d}t}=\alpha I-(h_{2}+\delta_{3})Q\\ \\
\frac{\mathrm{d}R}{\mathrm{d}t}=h_{1}I+h_{2}Q
\end{array}
\right.
代码如上,输出的感觉就是等式左边挤成一团。。。特别难看。。。求大神改进下,能不能让等式左边占两行?
在每个前面都加上\displaystyle 可能会好些, 这是最简单的方法了
对比图
\begin{displaymath}
\left\{
\begin{array}{l}
\frac{\displaystyle\mathrm{d}S}{\displaystyle\mathrm{d}t}=-(kI+k_{0}Q)S\\ \\
\frac{\displaystyle\mathrm{d}I}{\displaystyle\mathrm{d}t}=(kI+k_{0}Q)S-(\alpha+h_{1}+\delta_{1})I\\ \\
\frac{\displaystyle\mathrm{d}Q}{\displaystyle\mathrm{d}t}=\alpha I-(h_{2}+\delta_{3})Q\\ \\
\frac{\displaystyle\mathrm{d}R}{\displaystyle\mathrm{d}t}=h_{1}I+h_{2}Q
\end{array}
\right\}
\end{displaymath}