\ifthenelse{\equal{IJMPB}{\TschStyle}}{% 
%
\begin{table}[htbp] 
\tbl{Volume percent versus mass percent:
     The volume concentration $x_v$ and
     the mass concentration $x_m$ 
     of the gaseous components 
     of an idealized Earth's atmosphere}
{
\begin{tabular}{@{}lcccc@{}} \Hline 
\\[-1.8ex] 
Gas            & Formula                     & $x_v$             & $\varrho\,(298\,{\rm K})$ & $x_m$              \\
               &                             & $[{\rm Vol}\,\%]$ & $[{\rm kg}/{\rm m}^3]$    & $[{\rm Mass}\,\%]$ \\[0.8ex] 
\hline                                                                                                            \\[-1.8ex] 
Nitrogen       & ${\rm N}_2$                 & $\phantom{}78.09$ & 1.1449                    & $\phantom{}75.52$  \\
Oxygen         & ${\rm O}_2$                 & $\phantom{}20.94$ & 1.3080                    & $\phantom{}23.14$  \\
Argon          & ${\rm Ar}$                  & $\phantom{0}0.93$ & 1.6328                    & $\phantom{0}1.28$  \\
Carbon dioxide & ${\rm CO}_2$                & $\phantom{0}0.04$ & 1.7989                    & $\phantom{0}0.06$  \\[0.8ex]
\hline                                                                                                            \\[-1.8ex] 
\end{tabular}
}
\label{table:PB004}
\end{table}
%
}{}
\ifthenelse{\equal{arXivOrTeX4ht}{\TschStyles}}{% 
%
\begin{table}[htbp] 
{
\begin{center}
\vspace{0.5cm}
\begin{tabular}{|l|c|c|c|c|} 
\hline 
Gas            & Formula                     & $x_v$             & $\varrho\,(298\,{\rm K})$ & $x_m$              \\
               &                             & $[{\rm Vol}\,\%]$ & $[{\rm kg}/{\rm m}^3]$    & $[{\rm Mass}\,\%]$ \\ 
\hline                                                                                                             
Nitrogen       & ${\rm N}_2$                 & $\phantom{}78.09$ & 1.1449                    & $\phantom{}75.52$  \\
Oxygen         & ${\rm O}_2$                 & $\phantom{}20.94$ & 1.3080                    & $\phantom{}23.14$  \\
Argon          & ${\rm Ar}$                  & $\phantom{0}0.93$ & 1.6328                    & $\phantom{0}1.28$  \\
Carbon dioxide & ${\rm CO}_2$                & $\phantom{0}0.04$ & 1.7989                    & $\phantom{0}0.06$  \\
\hline                                                                                                             
\end{tabular}
\end{center}
}
\caption{Volume percent versus mass percent:
         The volume concentration $x_v$ and
         the mass concentration $x_m$ 
         of the gaseous components 
         of an idealized Earth's atmosphere}
\label{table:PB004}
%
\vspace{0.5cm}
%
\end{table}
%
}{}
