Beamer 中表达式与相应描述的比例

Question

我想稍微修改一下方程的显示。下面是我用来显示两个表达式的比率并使用指针描述项的代码。

我能够显示表达式，但我想知道是否可以将它们用作实分数，就像我们在使用\frac函数时得到的表达式一样。

\tikzstyle{na} = [baseline=-.5ex]


\begin{equation*}
a_i(t,x) =
        \tikz[baseline]{
            \node[fill=blue!20,anchor=base] (t1)
            {$ \tau C_i(t,x,\tau )\partial \tau$};
        } /
        \tikz[baseline]{
            \node[fill=red!20, ellipse,anchor=base] (t2)
            {$C_i(t,x,\tau) \partial \tau$};
        } 
\end{equation*}


\begin{itemize}[<+-| alert@+>]
 \item Coriolis acceleration
        \tikz[na] \node[coordinate] (n1) {};
    \item Transversal acceleration
        \tikz[na]\node [coordinate] (n2) {};
\end{itemize}

% Now it's time to draw some edges between the global nodes. Note that we
% have to apply the 'overlay' style.
\begin{tikzpicture}[overlay]
        \path[->]<1-> (n1) edge [bend right] (t1);
        \path[->]<2-> (n2) edge [bend right] (t2);

\end{tikzpicture}

上述代码的输出如下：

Answer 1

这是一个有效的例子：

\documentclass{beamer}
\usepackage{tikz}
\usetikzlibrary{shapes}
\tikzstyle{na} = [baseline=-.5ex]
\tikzstyle{every picture}=[remember picture]

\begin{document}
\begin{frame}
\begin{equation*}
a_i(t,x) =
        \frac{
        \tikz[baseline]{
            \node[fill=blue!20,anchor=base] (t1)
            {$ \tau C_i(t,x,\tau )\partial \tau$};
        }}{
        \tikz[baseline]{
            \node[fill=red!20, ellipse,anchor=base] (t2)
            {$C_i(t,x,\tau) \partial \tau$};
        }} 
\end{equation*}


\begin{itemize}[<+-| alert@+>]
 \item Coriolis acceleration
        \tikz[na] \node[coordinate] (n1) {};
    \item Transversal acceleration
        \tikz[na]\node [coordinate] (n2) {};
\end{itemize}

% Now it's time to draw some edges between the global nodes. Note that we
% have to apply the 'overlay' style.
\begin{tikzpicture}[overlay]
        \path[->]<1-> (n1) edge [bend left] (t1);
        \path[->]<2-> (n2) edge [bend right] (t2);

\end{tikzpicture}
\end{frame}
\end{document}