Quantal master equation valid for any time scale

A new memoryless expression for the equation of motion for the reduced density matrix is derived. It is equivalent to that proposed by Tokuyama and Mori, but has a more convenient form for the application of the perturbational expansion method. The master equation derived from this form of equation in the first Born approximation is applied to two examples, the Brownian motion of a quantal oscillator and that of a spin. In both examples the master equation is rewritten into the coherent-state representation. A comparison is made with the stochastic theory of the spectral line shape given by Kubo, and it is shown that this theory of the line shape can be incorporated into the framework of the present theory.     

Syntheses of azo dyes containing 4,5-diphenylimidazole and their evaluation as analytical reagents

Eight azo dyes containing the 4,5-diphenylimidazole group have been synthesized, and their potential for determinations of metals has been studied spectrophotometrically. Of these reagents, the pyridylazo and quinolylazo derivatives are suitable as chromogenic reagents, the best being 2-(quinolylazo)-4,5-diphenylimidazole (QAI), which reacts with several metal ions. The copper and mercury complexes of QAI show molar absorptivities of the order of 80 000 l mol^?1 cm^?1.     

On finsler spaces with kropina metric

The curvature tensors and other important tensors of a Finsler space with Kropina metric are studied. We find conditions for such a space to be affinely connected in Berwald's sense.     

Studies on fungal metabolites—XXXI: Anthraquinonoid colouring matters of Penicillium islandicum sopp and some other fungi (−)luteoskyrin, (−)rubroskyrin, (+)rugulosin and their related compounds

The structures of (+)rugulosin, (?)luteoskyrin and (?)rubroskyrin have been reexamined by NMR and new structures 18, 19 and 20 proposed respectively. Their absolute structures were established on the basis of the X-ray analysis of (+)dibromodehydrotetrahydrorugulosin (27). The minor analogous metabolites, (?)4a-oxyluteoskyrin (31) of P. islandicum and (+)4a-oxyrugulosin (32) of P. brunneum, have been formulated. On oxidation of (?)luteoskyrin and (+)rugulosin with pertrifluoroacetic acid (?)4a,4a′-dioxyluteoskyrin (33) and (+>4a,4a′-dioxyrugulosin (34) were formed, while with MnO₂ (+)4a,4a′-dehydrorugulosin (35) was obtained. The structures of lumiluteoskyrin (37), and deoxylumiluteoskyrin (38), photooxidation products of luteoskyrin and deoxyluteoskyrin, respectively, have been elucidated.     

Photochromism of single crystals composed of dioxazolylethene and dithiazolylethene

Although dioxazolylethene 1a did not show any photocoloration in the single crystalline phase, 1a displayed photochromism in the mixed crystal containing both 1a and dithiazolylethene 2a ; the mixed crystal changed color from colorless to red, orange, and yellow upon irradiation with light of appropriate wavelengths.     

Ir-catalyzed almost perfect enantioselective synthesis of helical polyaryls based on an axially-chiral sequence

Ir-catalyzed enantioselective [2 + 2 + 2] cycloaddition of tetraynes or an octayne with monoalkynes proceeded to give helically-chiral quinquearyl and noviaryl compounds, which respectively have four and eight consecutive axial chiralities, in an almost enantiomerically pure form.     

Electrothermal atomic absorption spectrometric determination of ng g-1 levels of cadmium in bone after dithizone extractions

After removal of lipid and acid digestion of bone samples, cadmium is separated from the matrix by two extractions with dithizone in carbon tetrachloride. The first extraction at pH 3–3.5 removes cadmium from the matrix; the second extraction, at pH 8.5 in the presence of 2-hydroxyethylethylenediaminetriacetic acid, is needed to prevent suppression of the cadmium signal by zinc. Cadmium is finally measured in the back-extract into 0.24 M hydrochloric acid. Less than 10 ng g^-1 cadmium in fresh bone can be determined within a relative standard deviation of 10%.