Secondary fragments description

In this paper we have shown that a direct quantitative relationship can be established between the RuC+/Ru+ and Ru2C+/Ru2 ion ratios in SIMS and the surface carbon formed by the ethylene/ Ru(001) interaction at 323 K. We have also shown that a direct relationship can be established between emitted hydrocarbon-containing secondary ions in SIMS and the small amounts of hydrocarbon species formed by the ethylene/Ru(001) interaction. The results are furthermore consistent with an ejection mechanism involving intact emission and simple fragmentation of the parent hydrocarbon species. Finally, the results of this study provide a relatively detailed description of the behavior of the rather small amounts of hydrocarbon species produced by the ethylene/ Ru(001) interaction, thus illustrating the potential of SIMS for investigating surface reactions. 

Early evidence for motion in the interior of proteins or their fragments came from infrared vibrational spectroscopy.36 It is usually assumed in interpreting such data that a harmonic potential and the resulting normal-mode description of the motions is adequate (see Chapt. IV.F).200-201 Although it is now known that this approximation is not generally applicable to the atomic motions in proteins (see above), the normal mode description is nevertheless useful for understanding certain aspects of the dynamics. It is most likely to be correct for the mainchain atoms of tightly bonded secondary structural elements, like a-helices and /3-sheets. 

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