答案1
这就是你要找的人吗?
\documentclass[12pt,a4paper]{article}
\usepackage[left=.45in,right=.45in,top=.6in,bottom=.6in,headheight=14.5pt]{geometry}
\usepackage{multirow}
\begin{document}
\centering
\begin{tabular}{|c|c|c|c|}
\hline
\multicolumn{4}{|c|}{Minimization with respect to}\\ \hline
\multirow{ 2}{*}{Model}& \multicolumn{3}{c|}{Fields}\\ \cline{2-4}
&$u$&$n$&$\bar{n}$\\ \hline
Local & & & \\ \hline
Non Local & & & \\ \hline
Micro & & & \\ \hline
\end{tabular}
\end{document}
最后三列宽度相等
\documentclass[12pt,a4paper]{article}
\usepackage[left=.45in,right=.45in,top=.6in,bottom=.6in,headheight=14.5pt]{geometry}
\usepackage{multirow}
\usepackage{array}
\newcolumntype{C}[1]{>{\centering\arraybackslash}m{#1}}
\begin{document}
\centering
\begin{tabular}{|c|C{2cm}|C{2cm}|C{2cm}|}
\hline
\multicolumn{4}{|c|}{Minimization with respect to}\\ \hline
\multirow{ 2}{*}{Model}& \multicolumn{3}{c|}{Fields}\\ \cline{2-4}
&$u$&$n$&$\bar{n}$\\ \hline
Local & & & \\ \hline
Non Local & & & \\ \hline
Micro & & & \\ \hline
\end{tabular}
\end{document}