How can I place a one-column-abstract in a two-column document?
This should make the trick. Important Note: This is a copy-paste from: I've just tested it
\documentclass[twocolumn]{article}
...
\begin{document}
... % \author, etc
\twocolumn[
\begin{@twocolumnfalse}
\maketitle
\begin{abstract}
...
\end{abstract}
\end{@twocolumnfalse}
]
If you use the multicol
package then you can easily mix different column format
\documentclass{article}
\usepackage{multicol}
\usepackage{lipsum}% for dummy text
\begin{document}
\begin{abstract}
\lipsum[1]
\end{abstract}
\begin{multicols}{2}
\lipsum[2]
\end{multicols}
\end{document}
The \twocolumn-command takes an optional argument, which will be printed in one-column-mode.