\begin{table}%t3
   %\centering
\par
      \caption{Thermodynamical parameters of the water-rich and water-poor subnebulae.\label{tab3}}
         \begin{tabular}[]{lcc}
	    \hline
            \hline
            \noalign{\smallskip}
             Thermodynamical & Water-rich  & Water-poor \\
	     parameters & subnebula & subnebula \\
           \noalign{\smallskip}
            \hline
           \noalign{\smallskip}
            Mean mol. weight (g/mole) & \hspace{0cm}18 & 3.1 \\
            $\alpha$ & \hspace{0.3cm}$10^{-5}$ & \hspace{0.2cm}$10^{-4}$    \\
            Disk's radius $R_{\rm D}$ ($R_{\rm Ur}$) & 75 & 500  \\
	    Initial disk's mass $M_{\rm D0}$ ($M_{\rm Ur}$) &\multicolumn{2}{c} {0.02}  \\
            $\dot{M}_0$ ($M_{\rm Ur}$/yr) & \multicolumn{2}{c} {$4\times 10^{-5}$}  \\
	    Characteristic time scale (yr) & \hspace{0.1cm}390 & \hspace{0cm}660  \\
                       \hline
         \end{tabular}
   \end{table}