Ein neuer,ergiebiger Zugang zu Dihydroactinodiolid und α-substituierten Furanderivaten

Dihydroactinodiolid 1 is formed in high yields by oxidation of the alcohols 2 and 3 and the ether 4 . Furthermore, the oxidation of the epoxy-alcohols 13 and 14 gives rise to the formation of furancompounds ( 15 and 16 , respectively).     

Optically induced transverse voltages in thin metal films

Results of experiments on laser induced voltages in metal films are summarized. The voltages are found to occur along certain directions in the plane of slant-angle vapour deposited films. A thermo-electric model based on periodic variations in the microscopic film structure, is described. The magnitude of the effect is proportional to the absorbed power/length between the contact points. Application of the films in the wavelength range 0.33–10.6μm is described and compared to more conventional detectors. A recent application, using the effect as a tool to profile non-uniformities in thin films, is also discussed.     

A domain structure in 3HeB

For the Ginzburg-Landau equations for ³He we derive a solution, which suggests the existence of a three-dimensional domain structure in the B-phase.     

Accurate determination of traces of sodium and potassium in rocks by ion exchange followed by atomic absorption spectroscopy

Sodium and potassium (5–1000 p.p.m.) in rocks such as peridotites and dunites can be determined accurately by ion-exchange separation followed by atomic absorption spectrophotometry. The samples are decomposed in sulphuric, hydrochloric and hydrofluoric acid mixtures, and after removal of hydrofluoric acid the cations are absorbed on a 90-ml column of AG50W-X8 cation-exchange resin. Vanadium and other anion-forming elements are eluted with 0.01 M nitric acid containing hydrogen peroxide. Then the alkali metals are eluted with 0.50 M nitric acid, while Mg, Mn, Ca, Ti, Al, Fe and other multivalent elements are retained by the column. The eluate fractions containing the respective alkali metals are measured directly by atomic absorption spectrophotometry against standards in 0.50 M nitric acid. Relevant elution curves, results for synthetic mixtures and for three international rock standards are presented and discussed.