Anomalous loss in depressed-cladding and W-fibres

Anomolous spikes in the loss spectrum of practical depressed-cladding fibres with a finite cladding and absorbing jacket can be explained in terms of a combination of three effects — the excitation conditions, the absorption behaviour of core and cladding modes, and the slight variation in the fibre diameter along its length.     

An efficient synthesis of oosporein

Fungal metabolite oosporein was prepared in four steps and 24% overall yield starting from 2,5-dimethoxytoluene. It was demonstrated that treatment of phoenicin with pyrrolidine and copper(II) acetate led to oosporein, whereas similar treatment of the isomeric ‘isophoenicin’ produced a benzofuran diquinone. No chromatography was required during any step of the synthesis.     

Generation of spatial solitons using non-linear guided modes

We investigate how two-dimensional spatial optical solitons can be generated in a non-linear Kerr medium using the non-linear guided modes of a weakly-guiding slab waveguide with a linear core and a non-linear cladding as the source of excitation. Symmetric, antisymmetric and asymmetric non-linear modes are considered, from which we determine the parameters of single solitons, oscillating two-soliton bound states, and two repelling solitons, respectively. Both the beam propagation method and inverse scattering transform are used.     

Low-energy manifestations of a new interactions scale: Operator analysis

Zeitschrift für Physik C Particles and Fields - We list all dimension sixSU(3)×SU(2)×U(1) invariant operators which can be used in a phenomenological analysis of deviations from the...     

Palladium and rhodium ureaphosphine complexes: exploring structural and catalytic consequences of anion binding

The addition of a chloride ion to Pd and Rh complexes supported by the ureaphosphine ligand L results in the formation of chelating diphosphine complexes that retain some catalytic activity.     

Superconductivity in quark matter

Superconductivity due to the pairing of relativistic quarks in ultra-dense matter is discussed. Ginzburg-Landau equations are derived, and the possibility of an Abrikosov vortex phase is considered.     

Three-triplet realisations of gauge models and deep-inelastic scattering

We investigate the predictions for very-high-energy inelastic neutrino scattering of three-triplet realisations of the weak-interaction gauge theories based on the groups O(3) and SU(2) × U(1).     

A test of the DWIA at 135 MeV using the 207Pb(p,p′) reaction

Data for the excitation of the strongly collective octupole doublet in ²⁰⁷Pb at E_X = 2.64 MeV is used to test the distorted wave impulse approximation (DWIA) at a proton bombarding energy of 135 MeV. A complex, effective local interaction derived from the nucleon-nucleon phase shifts is used together with the wave functions of Ring and Speth for the low-lying octupole state in ²⁰⁸Pb. The DWIA (including central and spin-orbit terms) is found to be in reasonable agreement with both the magnitude and shape of the observed cross section.     

Neutral weak currents and the proton-neutron mass difference

The logarithmically divergent contributions to the proton-neutron mass difference arising from the exchange of intermediate vector bosons are investigated. Within the framework of Weinberg's model we find a divergent contribution of opposite sign to the electromagnetic divergence which is, however, insufficient to cancel it completely.