Astigmatic coherence sensor for digital imaging

We present a novel sensor that measures the entire spatial coherence function within an aperture by use of a variable astigmatic lens. This sensor permits digital capture and processing of partially coherent fields. We demonstrate the sensor by sampling and computing the coherent modes of a three-dimensional incoherent source.     

Titrimetric determination of sulfate in mineral waters

The interaction of [PdCl₄]^2-_aqwith ethylene-bis(thioglycolic) acid (EBTGA) and β-ethylthioethylene(thioglycolic) acid (β-ETETGA), has been interpreted and evaluated quantitatively. The successive constants of palladium(II) with EBTGA and/or β-ETETGA in acid medium have been determined spectrophotometrically.     

Event-by-event fluctuations of the Kaon-to-Pion ratio in central Pb+Pb collisions at 158 GeV per nucleon

We present the first measurement of fluctuations from event to event in the production of strange particles in collisions of heavy nuclei. The ratio of charged kaons to charged pions is determined for individual central Pb+Pb collisions. After accounting for the fluctuations due to detector resolution and finite number statistics we derive an upper limit on genuine nonstatistical fluctuations, which could be related to a first- or second-order QCD phase transition. Such fluctuations are shown to be very small.     

Higher order speciation effects on plutonium L(3) X-ray absorption near edge spectra

Pu L(3) X-ray near edge absorption spectra for Pu(0-VII) are reported for more than 60 chalcogenides, chlorides, hydrates, hydroxides, nitrates, carbonates, oxy-hydroxides, and other compounds both as solids and in solution, and substituted in zirconolite, perovskite, and borosilicate glass. This large database extends the known correlations between the energy and shape of these spectra from the usual association of the XANES with valence and site symmetry to higher order chemical effects. Because of the large number of compounds of these different types, a number of novel and unexpected behaviors are observed, such as effects resulting from the medium and disorder that can be as large as those from valence.     

Electronic and photophysical properties of a novel phenol bound dinuclear ruthenium complex: evidence for a luminescent mixed valence state

A novel dinuclear ruthenium(II) complex bridged by dianionic bridge 3-(2-phenol)-5-(pyridin-2-yl)-1,2,4-triazole in which the ruthenium metal atoms are bound through N,N coordination to the pyridine and triazole and O,N coordination to the triazole and phenolate is described. The electrochemical, spectroscopic and photophysical behaviour of the dimer is compared with its associated N,N- and O,N-coordinated mononuclear complexes. The mixed valence complex was prepared electrochemically and a weak inter-valence charge transfer transition is observed which from Hush theory provides an electronic coupling matrix element of 666 cm(-1), suggesting the complex is weakly coupled and valence trapped. In its native state the dinuclear compound is essentially non-emissive but upon the oxidation of the O,N moiety luminescence from the complex is reversibly switched on at 0.3 V and reversibly switched off by application of 1.3 or 0 V. To our knowledge this is the first report of a luminescent mixed valence ruthenium complex.