latex双栏

1. \newlength{\halfpagewidth}

   \setlength{\halfpagewidth}{\linewidth}

   \divide\halfpagewidth by 2

   \newcommand{\leftsep}{%

   \noindent\raisebox{4mm}[0ex][0ex]{%

   \makebox[\halfpagewidth]{\hrulefill}\hbox{\vrule height 3pt}}%

   \vspace*{-2mm}%

   }

   \newcommand{\rightsep}{%

   \noindent\hspace*{\halfpagewidth}%

   \rlap{\raisebox{-3pt}[0ex][0ex]{\hbox{\vrule height 3pt}}}%

   \makebox[\halfpagewidth]{\hrulefill}%

   }

   \begin{multicols}{2}

   Bla bla...

   \end{multicols}

   %

   \leftsep

   \begin{equation*}

   \label{eqn:planar:Hz02}

   \begin{cases}

   \delta A + \kappa B = 0 \\

   (\kappa\sin\kappa d-\gamma\cos\kappa d)A+(\kappa\cos\kappa d+\gamma\sin\kappa d)B=0

   \end{cases}

   \end{equation*}

   \rightsep

   %

   \begin{multicols}{2}

   Bla bla...

   \end{multicols