Alternative techniques for solving systems of nonlinear equations

In this paper a selection of familiar iterative techniques are compared for their ability to solve the large nonlinear equation systems typically encountered in econometrics. The general convergence theory of methods based on Jacobi and Gauss-Seidel iterations (including a new-comer, Fast Gauss-Seidel) is taken as far as possible. Where extensions are impossible, numerical comparisons are made on some representative econometric models — the winner is Fast Gauss-Seidel. Previous convergence and comparison theorems have concerned only certain specialised equation systems not encountered in econometrics. A shortcoming of econometric theory, in that neither convergence analysis nor evaluation of these techniques has been available to guide the applied economist, is thereby overcome.     

Transverse asymmetry AT' from the quasielastic 3He(e,e') process and the neutron magnetic form factor

We have measured the transverse asymmetry A(T') in 3He(e,e(')) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q2 values from 0.1 to 0.6 (GeV/c)(2). The neutron magnetic form factor G(n)(M) was extracted based on Faddeev calculations for Q2 = 0.1 and 0.2 (GeV/c)(2) with an experimental uncertainty of less than 2%.     

Inhibierung der Autoxydation von Polypropylenoxid durch KOH

Ohne Zusammenfassung     

The dynamic stereochemistry of the allylic ligand in a μ-allylic complex of platinum(II)

¹H NMR studies of an equilibrium mixture of 1,1,1,5,5,5-hexafluoropentane-2,4-dionato-π-allylplatinum(II) [IA] and bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)bis(μ-allyl)diplatinum(II) [IB] show that the μ-allylic ligands of (IB) exhibit temperature dependent tautomeric behaviour, giving rise to a site-exchange between protons on these ligands.     

Quaternary adamantine selenides and tellurides of the form I III IV VI4

The preparation of a range of polycrystalline Selenides and Tellurides of the form I III IV VI₄ was undertaken. Twelve Selenides with quaternary composition were prepared but the eight Tellurides attempted did not grow as quaternaries. Single crystal samples of CuGaSnSe₄ were grown by vapour transport. X-Ray powder photography confirmed that the quaternary Selenides have tetragonal Chalcopyrite structure with a c/a ratio of approximately 2. A systematic variation of unit cell volume and of c/a was found over the entire range of compounds grown.