\ifthenelse{\equal{IJMPB}{\TschStyle}}{% 
%   
\begin{table}[htbp] 
\tbl{Mass densities of gases at normal atmospheric pressure 
     (101.325 ${\rm kPa}$) and standard temperature ($298\,{\rm K}$)}
{
\begin{tabular}{@{}lccc@{}} \Hline 
\\[-1.8ex] 
Gas              & Formula      & mass density\,$\varrho$  & Source                     \\
                 &              & $[{\rm kg}/{m}^3]$       &                            \\[0.8ex] 
\hline                                                                                  \\[-1.8ex] 
Nitrogen         & ${\rm N}_2$  & $ 1.1449 $               & Ref.~\refcite{Lide2002}    \\
Oxygen           & ${\rm O}_2$  & $ 1.3080 $               & Ref.~\refcite{Lide2002}    \\
Argon            & ${\rm Ar}$   & $ 1.6328 $               & Ref.~\refcite{Lide2002}    \\
Carbon Dioxide   & ${\rm CO}_2$ & $ 1.7989 $               & Ref.~\refcite{Lide2002}    \\[0.8ex] 
\hline                                                                                  \\[-1.8ex] 
\end{tabular}
}
\label{table:PB003}
\end{table}
% 
}{}
\ifthenelse{\equal{arXivOrTeX4ht}{\TschStyles}}{% 
%   
\begin{table}[htbp] 
{
\begin{center}
\vspace*{0.5cm}
\begin{tabular}{|l|c|c|c|}
\hline 
Gas              & Formula      & mass density\,$\varrho$  & Source                     \\
                 &              & $[{\rm kg}/{m}^3]$       &                            \\ 
\hline                                                                                   
Nitrogen         & ${\rm N}_2$  & $ 1.1449 $               & Ref.~\cite{Lide2002}       \\
Oxygen           & ${\rm O}_2$  & $ 1.3080 $               & Ref.~\cite{Lide2002}       \\
Argon            & ${\rm Ar}$   & $ 1.6328 $               & Ref.~\cite{Lide2002}       \\
Carbon Dioxide   & ${\rm CO}_2$ & $ 1.7989 $               & Ref.~\cite{Lide2002}       \\ 
\hline                                                                                   
\end{tabular}
\end{center}
}
\caption{Mass densities of gases at normal atmospheric pressure 
         (101.325 ${\rm kPa}$) and standard temperature ($298\,{\rm K}$)}
\label{table:PB003}
%
\vspace*{0.5cm}
%
\end{table}
% 
}{} 