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[en] The difficulties to recovery very small particles by conventional flotation need the development of all methods likely to give the best results. And this owing to the actual tendency which consists in including in the stocks of valorized ores, those with mineral particles finely scattered needing a very advanced grinding. Among these methods (va cum flotation, ionic flotation, column flotation, etc...), the electro flotation, which uses the electrolysis of pulp for it's airing seems to have a great interest but in fortunately its still on a laboratory scale. The passage to the industrial scale needs the putting in a conspicuous position of all possibilities of the method. However the studies have shown that the method should particularly be effective in recovering of several minerals finely ground. In this article, we have confirmed the fact in the case of galene. We have furthermore showed that the rate of recuperation increases with the decreasing of the size of the particles. The recovering is maximal for the particles under μm. This phenomen is different from the one observed in conventional flotation. We have given the reasons of this difference in this article.
[en] A summary is presented of the complex WKB theory for one-particle transfer reaction and it is shown how this theory gives a satisfactory description of these reactions close to the Coulomb barrier for the collision of 32S on 64Ni and 208Pb targets. (author). 14 refs., 4 figs., 2 tabs
[en] In this short review, we describe the integrability properties of the Calogero-type perturbations of one- and two-center Coulomb problems and of the Stark-Coulomb problem. We present the explicit expressions of their constants of motion and show that these systems admit partial separation of variables.
[en] The halo structure is expected to influence the reaction mechanisms in nuclear collisions. The aim of the experiment discussed in the present paper is to compare the fusion excitation functions for the systems 6He+64Zn and 4He+64Zn, in order to investigate the effects of the 6He two-neutron halo structure on the fusion reaction mechanism at energies around the Coulomb barrier. In particular, new fusion cross-sections for the 4He+64Zn systems at sub-barrier energies were measured to cover the same energy region of our previous measurements for 6He+64Zn. The fusion cross-section was measured by using an activation technique. We have observed an enhancement of the fusion cross-section in the reaction induced by 6He when compared to the one induced by 4He on the same 64Zn target.
[en] The spectral properties of Dirac operators with singular potentials that are constructed by means of a cut-off procedure are investigated. The invariance of the essential spectrum is proved, norm resolvent convergence of the cut-off operators is established and spectral gap formulas are proved
[en] Diagrammatic theory for Periodic Anderson Model has been developed, supposing the Coulomb repulsion of f — localized electrons as a main parameter of the theory. f -Electrons are strongly correlated and c -conduction electrons are uncorrelated. Correlation function for f - and mass operator for c -electrons are determined. The Dyson equation for c - and Dyson-type equation for f -electrons are formulated for their propagators. The skeleton diagrams are defined for correlation function and thermodynamic functional. The stationary property of renormalized thermodynamic potential with respect to, the variation of the mass operator is established. The result is appropriate both for the normal and for the superconducting states of the system.