]>

(a)

(b)

Figure 3: Plots of$\mathrm{\hspace{0.17em}\hspace{0.17em}}\delta$(${\text{H}}_2\text{:}$3) versus $\delta$(${\text{H}}_2\text{:}$2) (a) and $\delta$(Se: 3) versus $\delta$(Se: 2) (b).