\begin{table}%t1
\caption{\label{alpha_rs}Values of model parameters as~$r_0$ varies. }
%\centering
\par
\begin{tabular}{rrrrrrr}
\hline\hline
$r_0$ &~$r_1$ &~$r_2$ &~$r_3$ &~$r_4$ &$R$(cm) &~$R_\omega$ \\
\hline
0.20  & 0.25 & 0.40 & 0.25 & 0.35 &~$5.6\times 10^{10}$ &~$6.49\times 10^4$\\
0.64  & 0.70 & 0.80 & 0.70 & 0.80 &~$6.96\times 10^{10}$ &~$10^5$ \\
0.775 & 0.80 & 0.85 & 0.80 & 0.85 &~$8.0\times 10^{10}$ &~$1.32\times 10^5$\\
\hline
\end{tabular}
\end{table}