The surface fraction of 18O was in all samples more than one order of magnitude greater than the natural background abundance (Fig. 3), thus confirming that the reliable values of D* and k* can be obtained from the same experiment according to
The surface fraction of 18O was in all samples more than one order ofmagnitude greater than the natural background abundance (Fig. 3),thus confirming that the reliable values of D* and k* can be obtainedfrom the same experiment according to