带子图的图题空间

Question

我无法对齐垂直空间。间隙太大。我想使用 \vspace{-1ex} 代码，但我做不到。

\begin{figure}[h]
    \centering
    \begin{subfigure}[b]{0.45\textwidth}
        \includegraphics[width=\textwidth]{Figures/Chapter I/Added/2c.png}
        \caption{}
        \label{fig:1.6b}
    \end{subfigure}
    ~ %add desired spacing between images, e. g. ~, \quad, \qquad, \hfill etc. 
      %(or a blank line to force the subfigure onto a new line)
    \begin{subfigure}[b]{0.45\textwidth}
        \includegraphics[width=\textwidth]{Figures/Chapter I/Added/2d.png}
        \caption{}
        \label{fig:1.6c}
    \end{subfigure}
    \caption{(a), (b) [\cite{13}]}\label{fig:1.6}
\end{figure}

https://ibb.co/w0r12qt

Answer 1

\documentclass{article}

\usepackage[]{subcaption}
\usepackage[demo]{graphicx}


\begin{document}
    
    
    \begin{figure}[h]
        \centering
        \begin{subfigure}[b]{0.45\textwidth}
            \includegraphics[width=\textwidth]{Figures/Chapter I/Added/2c.png}
            \caption{}
            \label{fig:1.6b}
        \end{subfigure}
        ~ %add desired spacing between images, e. g. ~, \quad, \qquad, \hfill etc. 
        %(or a blank line to force the subfigure onto a new line)
        \begin{subfigure}[b]{0.45\textwidth}
            \includegraphics[width=\textwidth]{Figures/Chapter I/Added/2d.png}
            \caption{}
            \label{fig:1.6c}
        \end{subfigure}
            \vspace{-2\baselineskip}
        \caption{(a), (b) [\cite{13}]}\label{fig:1.6}
    \end{figure}
\end{document}

或者——你可以尝试以下

\documentclass{article}

\usepackage[labelformat=empty,skip=1em]{subcaption}
\usepackage[demo]{graphicx}


\begin{document}
    
    
    \begin{figure}[h]
        \centering
        \begin{subfigure}[b]{0.45\textwidth}
            \includegraphics[width=\textwidth]{Figures/Chapter I/Added/2c.png}
            \caption{}
            \label{fig:1.6b}
        \end{subfigure}
        ~ %add desired spacing between images, e. g. ~, \quad, \qquad, \hfill etc. 
        %(or a blank line to force the subfigure onto a new line)
        \begin{subfigure}[b]{0.45\textwidth}
            \includegraphics[width=\textwidth]{Figures/Chapter I/Added/2d.png}
            \caption{}
            \label{fig:1.6c}
        \end{subfigure}
                \vspace{-2\baselineskip}
        \caption{(a), (b) [\cite{13}]}\label{fig:1.6}
    \end{figure}
\end{document}