\node[terminal={below}{$v_{\mathrm{I}}(t)$}] (a) at (0,0) {}; \node[terminal={below left}{$\frac{\mathrm{d}i(t)}{\mathrm{d}t}$}] (b) at (3,0) {}; \node[terminal={below}{$i(t)$}] (c) at (6,0) {}; \node[terminal={below}{$\frac{\mathrm{d}v_{\mathrm{O}}(t)}{\mathrm{d}t}$}] (d) at (9,0) {}; \node[terminal={below}{$v_{\mathrm{O}}(t)$}] (e) at (12,0) {}; \draw[amark=$\nicefrac{1}{L}$] (a) to (b); \draw[amark=$s^{-1}$] (b) to (c); \draw[amark=$\nicefrac{1}{C}$] (c) to (d); \draw[amark=$s^{-1}$] (d) to (e); \draw[amark=$-\nicefrac{1}{L}$] (e) to[bend right=30] (b); \draw[amark=$-\nicefrac{R}{L}$] (c) to[bend left=45] (b);