highly significantp < .0001
The content of each individual element, except Fe, showed highly significant differences between the inner structure and the surface (results from Wilcoxon‐test: p < .0001*, for p ‐values see Table A1 ).
The content of each individual element, except Fe, showed highly significant differences between the inner structure and the surface (results from Wilcoxon‐test: p < .0001*, for p ‐values see Table A1 ).