Extraction of copper(II) and nickel(II) by long-chain aliphatic dioximes

In the search for a selective nickel extractant symmetric dialkyl dioximes have been studied in the extraction of copper and nickel ions from ammoniaca     

Ω− produced in K−p reactions at 4.2 GeV/c

Forty $\text{Ω}{}^{\mathrm{?}}$ events have been observed in a large (133 events/βb) experiment at 4.2 GeV/c incident K^? momentum. Thirty nine of the events come from the three-body reaction $\text{K}{}^{\mathrm{?}}\text{p}\text{→Ω}{}^{\mathrm{?}}\text{K}{}^{\mathrm{+}}\text{K}{}^0$. The $\text{Ω}{}^{\mathrm{?}}$ is mainly produced in the forward hemisphere (direction of the incident K^?). The lifetime is measured to be τ = (0.75 _+0.14?0.11 × 10^?10 sec substantially less than the Particle Data Group value of (1.3 _?0.3^+0.2) × 10^?10 sec. The mass is determined to be 1671.7 ± 0.6 MeV, in good agreement with other determinations. The decay asymmetry parameter α (for the decay mode $\text{Ω}{}^{\mathrm{?}}\text{→ Λ}\text{K}{}^{\mathrm{?}}$) is found to be ?0.2 ± 0.4.     

Usage de l'Algèbre de Lie su (n) dans l'Etude des Systèmes Quantiques à n Etats. V. Application aux Systèmes composés

We adapt the use of the Lie algebra su (n) we proposed in former papers to a system made up of two subsystems (respectively, n_A and n_B states). We show how reduced density operators, correlation problems, and overall and reduced evolution equations, may be made precise with this formalism.     

Endor of a dislocation center in a deformed silicon

We present the first ENDOR measurements on dislocations in silicon, which measurements directly show the extended nature of the electron wave function on the dislocation.     

On a Berry-Esseen theorem for compound Poisson processes

The well-known Berry-Esseen theorem concerning the rate of convergence to a stable law for a sum of independent identically distributed (i.i.d.) random variables is adapted to the case of a compound Poisson process, considered in the collective risk theory. As a consequence the rate of convergence of the Edgeworth expansion to the compound Poisson distribution is examined for all positive values of the time variable, in both cases where the moments of the claim distribution converge or diverge. As a by product the results obtained by T. Höglund [1] concerning the sum of a fixed number (n) of i.i.d. random variables are presented in an alternative manner. His theorems concerning the limiting behaviour for n → ∞ can be transformed slightly in order to make them hold for all n. It is explained how the result on the estimation of the rate of convergence in a limit theorem with a stable law fits with the results obtained by K.I. Satyabaldina [2].     

Anionic polymerization of methacrylonitrile—II.: Polymerization with 1,1-diphenyl-n-hexyllithium and sec-butyllithium as initiators

The anionic polymerization of methacrylonitrile has been investigated at ?75° in toluene with 1,1-diphenyl-n-hexyllithium and sec-butyllithium as initiators. With both initiators, initiation was fast and no unreacted initiator was left. The efficiency was much higher for 1,1-diphenyl-n-hexyllithium than for sec-butyllithium probably for steric reasons. With both initiators, a second order dependence on initiator was found. To check that this is not an artifact resulting from measurements in a medium starting to gel at a point which is difficult to detect precisely, kinetic measurements were also carried out with 2-polystyryl-l,l-diphenylethyllithium as an initiator. Second order kinetics were again obtained; the propagation rate constants, taking into account the efficiencies of initiators, were the same within experimental error for all three initiators. Viscosity measurements performed on a methacrylonitrile “capped” 2-polystyryl-l,l-diphenylethyllithium initiator showed the living polymethacrylonitrile chains to be associated.     

Nonisothermal model of asymmetric fluids

Several studies have been devoted to the investigation of the properties of fluid models with asymmetric stress tensors [1–5].In the following we consider the peculiarities of the Grad nonisothermal model [1]. It is shown that for the case of a nonuniform temperature field in a fluid in the general case there is an intersection of the thermal flux with the moment stress flux. Account for the flux intersection leads to change of the moment of momentum and specific entropy equations.In those cases when the physical characteristics of the medium in the flow region may be considered constant, the flux intersection may influence the fluid flow only through the boundary conditions.Thus, for example, the asymmetric moment stresses created by the temperature gradient will drive a fluid layer into motion if one of the layer surfaces is free.