$$\begin{aligned}

&\text { Table } 1 \text { The $L_{1}$ error and convergence order for Problem 1 }\\

&\begin{array}{llcccccc}

\hline & \multicolumn{2}{c} {\text { Sen's scheme }[30]} & \multicolumn{2}{c} {\text { Present scheme }} & \multicolumn{2}{c} {\text { Karra's scheme }[12]} \\

\cline { 3 - 4 } \cline { 5 - 6 } \cline { 7 - 8 } \alpha & Cell \quad number & h_{1 / 8} & h_{1 / 16} & h_{1 / 8} & h_{1 / 16} & h_{1 / 64} & h_{1 / 128} \\

\hline

& $9 \times 9$ & 1.71(-03) & & 1.72(-03) & & 1.88(-02) & \\

0 & $10 \times 10$ & 1.23(-03) & 3.13 & 1.24(-03) & 3.11 & 1.16(-02) & 4.59 \\

& $14 \times 14$ & 4.08(-04) & 3.28 & 4.31(-04) & 3.14 & 2.44(-03) & 4.63 \\

\hline & $14 \times 14$ & 1.10(-01) & & 1.23(-01) & & 2.29(-01) & \\

$10 / 3$ & $19 \times 19$ & 3.97(-02) & 3.33 & 4.03(-02) & 3.66 & 8.24(-02) & 3.35 \\

& $27 \times 27$ & 1.19(-02) & 3.43 & 1.07(-02) & 3.77 & 2.12(-02) & 3.86 \\

\hline & $14 \times 14$ & $\operatorname{div}$ & & 9.09(-01) & & 6.67(-01) & \\

& $19 \times 19$ & $\operatorname{div}$ & $-$ & 3.33(-01) & 3.29 & 3.20(-01) & 2.41 \\

10 & $27 \times 27$ & 1.43(-01) & $-$ & 1.00(-01) & 3.42 & 1.26(-01) & 2.65 \\

& $33 \times 33$ & 6.34(-02) & 4.05 & 4.94(-02) & 3.51 & 4.98(-02) & 4.67 \\

\hline

\end{array}

\end{aligned}$$

这是用Mathpix 生成的让后我改了一下  报错了。。