Etude des fragmentations en spectrographie de masse de dithiannes-1,3 substitués en 2 par des groupements insaturés

The mass spectra of the title compounds always show an intense molecular ion. Some fissions involve loss of the ethylenic group, while others are related to cleavage of the dithiane ring, eventually followed by recyclizations involving the ethylenic chain stabilized by the resonance possibilities. If a phenyl group is present in the ethylenic chain, the spectra are modified by the formation of the very stable benzothiopyrylium ion.     

A characterization of Chebyshev-Cramer expansions

It is shown that Chebyshev-Cramér expansions are uniquely determined in a wide class of approximating functions.     

Scattered-wave calculations of photoionization cross-sections and asymmetry parameters for CO,H2O and H2S

Partial photoionization cross-sections and asymmetry parameters are calculated for the valence orbitals of the molecules CO, H₂O, and H₂S and of the atoms O and S using a recently developed extension of the self-cosistent field— Xα—scattered-wave method to continuum states. The convergence of the partial-wave expansions for both initial and final states is studied for electron kinetic energies in the range 2–1000 eV. Since convergence is very slow at high kinetic energies, the interesting region between 2 and 50 eV is emphasized, and comparisons are made with experimental UV photoemission results where such data are available. Overall the method appears to be far more reliable than previous calculations for polyatomic molecules which have used plane-wave or orthogonalized plane-wave final states.     

An analysis of the Einstein-Podolsky-Rosen correlations in terms of events

It is shown that Bell's inequalities can be derived from two general assumptions bearing on events, namely the possibility of their retrodiction and their locality. The meaning of a possible violation of the retrodiction principle is interpreted by making use of the many-worlds formulation of quantum mechanics.     

Energy levels in the nucleus 156Dy through the 159Tb(p, 4nγ)156Dy reaction

Using the ¹⁵⁹Tb(p, 4nγ)¹⁵⁶Dy reaction at E_p = 27 to 51 MeV and standard on-line γ-ray spectroscopy methods, the energies and decay properties of members of various rotational bands in the nucleus ¹⁵⁶Dy have been investigated, i.e. the ground-state band up to 14_g⁺, the β-vibrational band up to 14_β⁺,the γ-vibrational band up to 11_γ⁺,and two other bands, one with odd-spin levels up to 11, the other with even-spin levels up to 10. The results are compared with various calculations in the framework of the collective model, and no satisfactory fit is obtained; possible improvements of the model to remove these discrepancies are suggested.