The quantum 2-sphere as a complex quantum manifold

We describe the quantum sphere of Podles for c = 0 by means of a stereographic projection which is analogous to that which exibits the classical sphere as a complex manifold. We show that the algebra of functions and the differential calculus on the sphere are covariant under the coaction of fractional transformations with SU _q(2) coefficients as well as under the action of SU _q(2) vector fields. Going to the classical limit we obtain the Poisson sphere. Finally, we study the invariant integration of functions on the sphere and find its relation with the translationally invariant integration on the complex quantum plane.     

Washboard effect of the moving vortex lattice in high-T c superconductors: numerical simulation

Using a simple model of the moving vortex lattice, the washboard effect in the mixed state of high-T _c superconductors, which is due to the interference between the intrinsic oscillation of the vortex lattice and the applied ac driving current, is investigated by numerical simulation. The obtained numerical results are in good agreement with recent experimental measurements on Y BCO crystal [Phys. Rev. Lett. 74, 3684 (1995)]. We also study the case when the ac driving current consists of two frequencies, and observe that the corresponding washboard effect is related not only to the two basic frequencies of the ac current but also to their combination terms.     

Light-particle emission in the reactions of 16O with Ti

Inclusive energy spectra and angular distributions for heavy ions $\text{(Z ≧ 3)}$ produced in the reactions of 227 MeV and 310 MeV ¹⁶O with Ti were measured. Also measured at the projectile energy of 310 MeV were energy and angular correlations between light charged particles (Z ≦ 2) and heavy ions. From comparisons with statistical model calculations upper limits to the complete fusion cross sections of 647 mb and 265 mb were derived for projectile energies of 227 MeV and 310 MeV, respectively. At 310 MeV the cross section of incomplete fusion processes was estimated to be over 505 mb. Emission of fast, high-energy α-particles and protons was observed to be a characteristic feature of quasi-elastic, deep-inelastic and fusion-like reactions. Average multiplicities of fast light particles in coincidence with heavy ions at +20° and +40° were estimated to be of the order of 1. The prompt emission of light appears to be the principal mechanism which limits complete fusion. A second component of α-particles observed in coincidence with deep-inelastic projectile-like fragments and having an energy comparable to Coulomb energies of particles emitted from target-like and projectile-like fragments appears as an excess yield in the direction of the recoiling target-like fragments. This component cannot be accounted for in terms of sequential emission processes and may result from a mechanism other than the one which leads to fast particle emission.     

A fully automated procedure for the determination of sodium hypochlorite and hydrogen peroxide, based on the use of a porous catalytic silver electrode

A new approach to the automated determination of sodium hypochlorite and hydrogen peroxide is described, based on the use of a porous catalytic silver electrode. The principle of both methods involves the quantitative liberation of oxygen, which is measured coulometrically by the electrode. The procedures are suitable for the continuous monitoring of the contents of bleaching baths.