cwtex with bkai and bsmi fonts

LyX source file
LaTeX source file

\documentclass{extarticle}
\renewcommand{\familydefault}{\rmdefault}
\usepackage[T1]{fontenc}
\usepackage{CJKutf8}
\usepackage[a4paper]{geometry}
\geometry{verbose,tmargin=0.75in,bmargin=0.75in,lmargin=0.75in,rmargin=0.75in}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amssymb}
\usepackage[authoryear]{natbib}
\begin{document}
\begin{CJK}{UTF8}{}%

\section{\CJKencfamily{UTF8}{bkai}

}

\CJKencfamily{UTF8}{bsmi}這是本文

{\Huge{}這是本文(最大字)}{\Huge\par}
\end{CJK}

\end{document}