We give a systematic discussion of the anomalous scattering of Bogoliubov excitations at sharp N–S and S–N boundaries as well as quasi-particle tunneling in N–S–N and S–N–S geometries. The relation between the transmission resonances (E > Δ) and the bound states (E < Δ) in N–S–N and S–N–S geometries is explicitly exhibited. We also work out the extra thermal resistance due to scattering by a normal layer imbedded in a superconductor and by a superconducting layer imbedded in a normal metal, with results different from that obtained by Shikin.

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DANIEL COZAK, FRANFOIS GAUVIN, and JACQUES DEMERS. Can. J. Chem. 64, 71 (1986). The paramagnetic 'H nmr spectra for manganocene (I) and 1 ,I '-dimethylmanganocene (2), and the I3C nrnr spectra for 1,l '-diethylmanganocene (3) have been recorded in toluene solvent over a -90 to 90°C temperature range. 1 shows a low field and a high field ring proton resonance in its spectrum near -59°C. At higher temperatures the low field resonance is prevalent and becomes gradually averaged due to a fast spin exchange process that dominates the spectrum at 90°C. For the ring substituted derivatives 2 and 3, resonances due to only one paramagnetic species were detected in the low temperature range. Above ambient temperature a new spectrum due to rapid spin exchange averaging is observed for these complexes. Results are readily interpreted in terms of ground state molecular cross-over exchanges between the 2~2 , , Chem. 64, 71 (1986). Nous avons enregistrC les spectres de larmn 'H du manganockne (I), du dimCthyl-1,l' manganockne (2) ainsi que les spectres de rksonance du 13C pour le diCthyl-1 , 1 ' manganocene 1 differentes temperatures entre -90 et 90°C. Le spectre du composC 1, dCterminC i -59"C, prCsente deux resonances paramagnCtiques dues,aux protons annulaires. La rCsonance se trouvant a champs faible domine les spectres dCterminCs i plus hautes temperatures. A 90°C, ce signal est dO a un spectre moyen cause par un Cchange rapide entre plusieurs Ctats paramagnktiques de la molCcule. Les spectres des composCs 2 et 3, dCterminCs B basse tempCrature, prCsentent un seul Ctat paramagnktique. Aux tempkratures superieures i celles de la pikce, un nouveau spectre, dO aussi i un Cchange rapide entre plusieurs Ctats paramagnCtiques, remplace graduellement le premier. Les rCsultats expCrimentaux sont interprCtCs en fonction de la dynamique des Ctats Clectroniques fondamentaux *E~,, 6~I g et 2~I g connus pour ces molCcules.