Permittivity, dielectric loss tangent, radial coupling coefficient, and radial frequency constant have been measured as a function of composition for pressure-sintered Li,rNa,-,NbO, in the range 0.015~xS0.15. An anomaly in each of these properties when plotted as a function of composition is associated with a structural transition between 2 ferroelectric phases; this transition lies near room temperature for compositions where x ~0 . 1 2 . Compositions near this phase boundary exhibit room-temperature properties which are of interest for highfrequency filter applications.

Benzylamine oxidase from pig plasma has been studied by a variety of chemical and physical techniques. 1. Analytical ultracentrifugation, gel electrophoresis and isoelectric-focusing studies suggest that the enzyme is composed of two subunits with closely similar primary structures. 2. E.s.r. and n.m.r. measurements show that the enzyme contains two well-separated (greater than 0.6 nm) Cu2+ ions at chemically distinct sites. Each Cu2+ ion is coordinated by two water molecules, one 'axial' and the other 'equatorial'. Both water molecules undergo fast exchange (10(5)--10(8) s-1) with solvent and are deprotonated in the pH range 8--9, but only the equatorial water molecule is displaced by the inhibitors N3- and CN-. 3. Kinetic and e.s.r. measurements show that azide and cyanide compete against O2 binding and also make the two Cu2+ sites identical. It is concluded that Cu2+ must participate in the re-oxidation of reduced enzyme by molecular O2.

Pressure-sintered Li x Na i _ x Nb0 3 in the range 0.015 ~ x ~ 0.15 exhibits electromechanical properties amenable to high-frequency device applications with radial-frequency constants fR(r) between 1.75 and 1.95 kHzm, coupling coefficients up to 0.4, and permittivities between 100 and 200. The temperature and time dependencies of fR are shown to be strongly related to composition, where for x = 0.12, the temperature coefficient between -40 and 80°C is -2X 1O-4°C -i and the ageing coefficient is -2.5X 10-3 per decade. The results are discussed in relation to composition and with respect to anomalies at phase transitions in (Li,Na)Nb0 3 .

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The pH dependences of fluorescence intensities and flash photolysis transients are reported for I-hydroxynaphthalene-2-sulphonate and I-hydroxynaphthalene-4-sulphonate in aqueous solution.From the fluorescence and phosphorescence spectra and pK(So) values of 9.58 (2-sulphonate) and S.27 (4-sulphonate), pK(S1) values of 0.4 and -0.1 respectively, and pK(T1) values of 7.9 and 7.2, are estimated. The pK(T1) estimates agree moderately well with the direct (but approximate) values 7.5 and 7.1 from the flash photolysis transient intensities, and the pK(S1) estimates are shown to be acceptably consistent with pK(S1) -IOgroT/T' determinations from the fluorescence intensities, T and 7' being the lifetimes of the naphthol and naphtholate forms respectively. Though both forms of the 2-sulphonate fluoresce, thus resembling 2-naphthol rather than 1-naphthol, the fluorescence intensity of the naphthol form behaves anomalously in remaining constant throughout the pH range 1-8, even when that of the naphtholate form is changing markedly. This and other peculiarities of I-hydroxynaphthalene-2-sulphonate suggest the presence of a n internally hydrogen-bonded form which fluoresces because it avoids the quenching attributable to hydrogen bonding to the solvent.An increase in the fluorsscence intensity of the naphthol forms at higher acid concentrations is shown to be caused by the added anions, which presumably interfere with the solvent quenching mechanism. The perchlorate ion has a particularly large enhancing effect, similar to that of alcohols.