ESR in the Pd-Mn system: Some evidences of a bottlenecked relaxation for the Mn2+ ion

ESR experiments on Pd-Mn in the low Mn concentration region (200 ? c ? 5000 at. ppm) are reported. The results are consistent with the hypothesis of a bottlenecked resonance with different g-factors for the Mn²⁺ ions (2.055) and the electrons of Pd (2.25); besides, partial opening of this bottleneck can be achieved. A giant momentum for Mn²⁺ (9.15μ_B) is also confirmed.     

On the mechanism of the thermal naphthalene automerization,a comment

The title reaction is suggested to proceed by a reversible valence isomerization via a laterally bridge benzvalene (2). No analogous behaviour is expected for pyrene.     

Pearson's correlation between three variables; using students’ basic knowledge of geometry for an exercise in mathematical statistics

The well known recurrence formulae for means and standard deviations have been extended to encompass bivariate data. The effectiveness of this technique is enhanced with the aid of a microcomputer.     

High-efficiency volume reflection of an ultrarelativistic proton beam with a bent silicon crystal

The volume reflection phenomenon was detected while investigating 400 GeV proton interactions with bent silicon crystals in the external beam H8 of the CERN Super Proton Synchrotron. Such a process was observed for a wide interval of crystal orientations relative to the beam axis, and its efficiency exceeds 95%, thereby surpassing any previously observed value. These observations suggest new perspectives for the manipulation of high-energy beams, e.g., for collimation and extraction in new-generation hadron colliders, such as the CERN Large Hadron Collider.