[en] A simple, sensitive and selective determination method of oxalate has been investigated based on the fluorescence enhancement of Eu³⁺ -TTA, complex due to the formation of Eu³⁺ -TTA-oxalate ternary complex. An emission peak of Eu³⁺ -TTA, which is increased linearly with addition of oxalate, occurs at 610 nm in aqueous solution with excitation at 306 nm. The linear range of the calibration curve is 1 x10^-6 -8 x 10^-6 M and the detection limit is 1 x 10^-6 M. The effects of foreign ions were studied. The present method was applied to determine oxalate of two synthetic samples

[en] This paper is unique in that the electroluminescence (EL) display device is fabricated on a curved surface using the pad-printing method. The precision of the pad-printing process is explored to verify whether it can be used for micro patterning. The minimum pattern size and pattern distortion, which is caused by use of the pad, were tested and simulated. The minimal pattern was found to be 35 µm wide and 2.4 µm thick. Pattern distortion when pad-printing on a flat surface, caused by the deformation of the silicon pad, was less than 5 µm. Numerical analysis shows how to estimate pattern distortion when pad-printing on a curved surface. The proposed EL display device consists of five layers, namely a bottom electrode, dielectric layer, phosphor, transparent electrode and a bus electrode. The ink of each layer was reformulated with solvents and the pad-printing conditions were controlled. A PEN film was used first in order to realize the pad-printing process condition of each layer. Finally, the EL display device was printed onto a dish with a radius of curvature of 80 mm. The luminance was 180 cd m⁻²