Das Vorkommen von Aconits?ure im Zuckerrohrsaft und Colonialzucker

Ohne Zusammenfassung     

The synthesis of XTT: A new tetrazolium reagent that is bioreducible to a water-soluble formazan

A new tetrazolium salt, XTT, has been synthesized. XTT is reduced by a considerable variety of cell lines to a water-soluble formazan. XTT appears to merit further investigation as a reagent for broader application to cell culture assay systems.     

The oxidation of formic acid at noble metal electrodes Part 4. Platinum + palladium alloys

Formic acid oxidation has been studied on Pt + Pd alloys of known surface composition using cyclic voltammetry. The results are interpreted in terms of a strongly bound (poisoning) intermediate which adsorbs only on the Pt atoms and a direct oxidation path which involves an intermediate occupying a single site and a second intermediate occupying two sites. Steady state oxidation currents on the alloys at potentials in the range of about 0.4 to 0.9 V are larger than expected from a linear combination of the currents on the pure metals. This effect may be due to the modification of metal properties at the junction between two types of metallic atoms.     

Sulphuric—perchloric acid digestion of plant material for the determination of nitrogen,phosphorus, potassium,calcium and magnesium

Modifications of an earlier procedure to improve reliability in routine use are described. Contamination from glass beads and new digestion flasks may be significant. Other possible sources of error are discussed.     

Resolved fine structure of exciton complexes bound to phosphorus impurities in silicon

A Fabry-Pérot interferometer is used to observe resolved fine structure for two of the luminescence lines associated with exciton complexes bound to phosphorus impurities in silicon. The results are interpreted in terms of j-j couplings for the electrons and holes and give support for the recently proposed shell-model. Linewidths are obtained for the four luminescence lines associated with 1-, 4-, 5-, and 6- exciton complexes. The linewidths of the 4-, 5-, and 6- exciton peaks are found to be considerably broader than that of the single bound exciton.