Topological ergodic decompositions and applications to products of powers of a minimal transformation

For a minimal distal flow (X, T) and a positive integern, let be the largest distal factor of ordern. The existence of a denseG _δ subset ω ofX is shown, such that forx ∈ ω the orbit closure of (x,x,...,x) ∈ X ⁿ⁺¹ under τ =T ×T ² ... ×T ⁿ⁺¹ is π-saturated. In fact, an analogous statement for a general minimal flow is proved in terms of its PI-tower. On the way we get some topological “ergodic” decomposition theorems.     

IsoscalarE2 transition strengths in 10≦A≦48 nuclei

Electric quadrupole transition strengths for the 2 ₁ ⁺ ,T=1→0 ₁ ⁺ ,T=1γ-decay branches are summarized for 10≦A≦42 nuclei. In¹⁰B the corresponding branch has been remeasured by use of the⁹Be(p, γ)¹⁰B resonance reaction atE _p =320 keV; an upper limit of 0.6% is found. The variation of theE2 strengths within each individualT=1 isobaric multiplet reveals the particleor hole-character of the levels involved. The isoscalar 2 ₁ ⁺ →0 ₁ ⁺ transition strengths in 10≦A≦48 nuclei vary between 2 and 20 Weißkopf units showing drastic shell effects. Results for the ratio of neutron and proton matrix elements deduced from analogγ-decay studies and from inelastic pion scattering are compared.     

Relative weak mixing is generic

A classical result of Halmos asserts that among measure preserving transformations the weak mixing property is generic. We extend Halmos' result to the collection of ergolic extensions of a fixed, but arbitrary,aperiodic transformation T_0. We then use a result of Ornstein and Weiss to extend this relative theorem to the general(countable) amenable group.     

Water-activity and double-layer effects on the Fe(II)/Fe(Hg) reaction

The title subject is studied by electrode-kinetic measurements in acetate buffered potassium chloride and magnesium sulphate solutions of varied concentration at 25°C, using literature data for activity and double-layer properties. The results indicate that the Fe(II)/Fe(Hg) reaction occurs by an essentially symmetric (α near 1/2) ferrous-ion transfer (n=2), that this transfer is second order in water-activity dependence, and that it exhibits a smaller than classically expected double-layer effect. No specific interaction appears for any of the ions of the supporting salts. An e.c. reaction scheme is proposed for the Fe(Hg)/Fe(II) electrode in non-complexing aqueous solution.