Two-particle transfer reactions: A four-body treatment I

A method is proposed through which interaction between transferred nucleons can be introduced to all orders. The transition amplitude for the two-nucleon transfer reaction is thus obtained showing the relevant two-particle transition amplitude that describes the interaction between the transferred nucleons.In the presence of two-body bound state in the transferred pair the total cross section is split into two parts one describing the transfer of a bound system of two nucleons, the other part corresponds to corrections due to the continuum.General remarks about the application of these ideas to heavy-ion scattering are made.     

Hyperfine magnetic fields in Fe−Co alloys and their tempera ture dependences

We obtained⁵⁷Fe hyperfine field parameters from Fe₁−x-Co _x alloys (0≤x≤0.6) from 77 K to 900 K. We first discuss the origin of the low temperature hyperfine fields in terms of the 3d and 4s electrons at⁵⁷Fe atoms. The⁵⁷Fe hyperfine magnetic field (hmf) of Fe-Co alloys depends more weakly on temperature than the hmf of pure Fe. This temperature dependence occurs because the alignment of the magnetic moments at both the Fe atoms and at the Co atoms depend on temperature in the same way as the bulk magnetization of Fe-Co alloys.     

Semiclassical derivation of a local optical potential for heavy-ion elastic scattering

A semiclassical method to determine the contribution to the optical potential in the elastic channel due to the coupling to other processes taking place in heavy-ion collisions is developed. An application is made to the case of Coulomb excitation. The lowest-order term of our potential is shown to be identical to the potential derived by Baltz et al.     

Optimization of effective processing parameters of hybrid anti-corrosion Si/Zr sol–gel coatings doped with cerium salt for aluminum alloy 6061

Journal of Sol-Gel Science and Technology - In this study, the Taguchi method was used to design of experiment to obtain optimum conditions for hybrid Si–Zr sol–gel coating doped with...     

Beyond Chemoselectivity: Catalytic Site‐Selective Aldolization of Diketones and Exploitation for Enantioselective Alzheimer's Drug Candidate Synthesis

Site selectivity, differentiating instances of the same functional group type on one substrate, represents a forward‐looking theme within chemistry: reduced dependence on protection/deprotection protocols for increased overall yield and step‐efficiency. Despite these potential benefits and the expanded tactical advantages afforded to synthetic design, site selectivity remains elusive and especially so for ketone‐based substrates. Herein, site‐selective intermolecular mono‐aldolization has been demonstrated for an array of prochiral 4‐keto‐substituted cyclohexanones with concomitant regio‐, diastereo‐, and enantiocontrol. Importantly, the aldol products allow rapid access to molecularly complex ketolactones or keto‐1,3‐diols, respectively containing three and four stereogenic centers. The reaction conditions are of immediate practical value and general enough to be applicable to other reaction types. These findings are applied in the first enantioselective, formal, synthesis of a leading Alzheimer's research drug, a γ‐secretase modulator (GSM), in the highest known yield.     

The Somigliana ring dislocation

A basic elasticity solution applicable to an important class of internal stress problems related, for example, to fiber-matrix composites and spalling of cylindrical coatings is obtained. The basic problem that has been solved is that of the singular stress-displacement field resulting from the introduction of a Somigliana ring dislocation in an isotropic linear elastic solid. The Burgers vector of this dislocation has two components, one being normal to the plane of the circular ring dislocation (Volterra type) and the other being in the radial direction of the ring dislocation everywhere (Somigliana type). The analytical solution, in terms of complete elliptic integrals of the first, second and third kinds, is obtained using the Love stress function and Fourier transform. The results are verified numerically and by examining various limiting cases, including the straight edge dislocation as the radius of the dislocation loop tends to infinity, the orthogonal pair of dipoles as the radius tends to zero, and the Lamé solution of a cylindrical bar and a cylindrical hole in an infinite medium as the axial location of the dislocation tends to minus infinity. The resulting analytical solution is considered as a step towards evaluating both the extended stress field around and interactions among various three-dimensional defects such as cylindrical cracks, fiber-tips and fiber-matrix debonding.