Pickup lens inspection on the 5th order aberration using shearing interference by grating with curve fitting algorithm

An optical system based on shearing interference using diffraction grating was applied, to carry out the aberration inspection process of the pickup lens of a digital versatile disc (DVD) at high speed. An algorithm was devised that processes points allocated on certain lines on a fringe and fits relations between the distance from basis point to the measurement points, and phase data of the fringe at these points to an equation of higher degree as curve fitting. Aberration was numerically estimated as the size of a certain coefficient. Simulation showed that this algorithm could detect all 5th order aberrations independently. An inspection system developed based on this optical system and algorithm detected aberration as accurately as a conventional interferometer that has been used as the standard, attaining an inspection time of 1/10-1/20. In comparison with the spot method, this system has 5th order aberration detecting ability and 1/3 the inspection time.     

Potentiometric performance of silver ion-selective electrodes based on tridentate Schiff base derivatives.

To examine the directivity for improving the silver ion discrimination ability of a Schiff base, three kinds of tridentate ligands were synthesized and compared with the similar quadridentate ligand as the silver ionophore. Among the Schiff base derivatives tested, 3-(2-pyridylethylimino)-2-butanoneoxime, having one oxime and a pyridine substituent, was found to be the best ionophore for a silver-ion electrode. The electrode based on this derivative exhibited good silver-ion selectivity, -log Kpot(Ag+,K+) = 3.8, comparable to that of a quadridentate Schiff base, N,N'-bis(2'-hydroxyimino-1'-phenylpropyleden)-1,3-propanediamine, reported previously, except for a pseudo Nernstian response (35.6 mV decade(-1)) with a wide silver-ion activity change in the activity change from 5.0 x 10(-7) to 7.9 x 10(-2) mol dm(-3).     

Dependence of NO2 sensitivity on thickness of oxide-sensing electrodes for mixed-potential-type sensor using stabilized zirconia

The effect of thickness of oxide-sensing electrode (SE) on NO₂ sensitivity of the planar sensor based on yttria-stabilized zirconia (YSZ) was examined at high temperatures. The sensitivity of the sensor increased with decreasing thickness of SE, and the highest sensitivity was obtained by using the thinnest layer of Cr₂O₃–SE (2.7 μm) at 700 °C. In the case of NiO–SE, the highest sensitivity was observed for the sensor using the 4-μm-thick SE even at a high temperature of 850 °C. Based on the results of the measurements for the complex impedances, the polarization curves, and the gas-phase NO₂ decomposition catalysis, it was confirmed that the catalytic activity to the gas-phase NO₂ decomposition on the oxide–SE matrix played an important role in determining the NO₂ sensitivity of the present sensors.     

Dual-wavelength-switching operation based on optical bistability in pump-bypassed ytterbium-doped fiber laser

The bistable feature of residual pump in a pump-bypassed Yb-doped fiber laser offers the potential to pump Er/Yb co-doped fiber in a bifurcated cavity for the lasing of the 1537 nm line. The results of our proof-of-concept demonstration show that the oscillations at 1040 nm and 1537 nm are operated in the wavelength-switching mode, and this suggests that the combination of optical bistability in a pump-bypassed fiber laser cavity with a bifurcated cavity could be one simple and efficient method for switchable dual-wavelength operation. PACS 42.55.Wd; 42.65.Pc; 42.79.Ta     

Synthesis of polyesters with pendant oxetane groups by the chemoselective alternating copolymerization of 3‐ethyl‐3‐(glycidyloxymethyl)oxetane with carboxylic anhydride and its photochemical reaction

The synthesis of polyesters with pendant oxetane groups by the chemoselective alternating copolymerization of 3‐ethyl‐3‐(glycidyloxymethyl)oxetane (EGMO) with carboxylic anhydride and the photochemical reaction of the resulting polymer was examined. The alternating copolymerization of EGMO with phthalic anhydride proceeded chemoselectively with quaternary onium salts under appropriate reaction conditions, and the corresponding soluble polymers with pendant oxetane groups with number‐average molecular weights of 4700–7200 were obtained in 72–87% yields. Furthermore, the photochemical reaction of the resulting polymers was examined with certain photoacid generators in the film state upon UV irradiation, and it was found that the photocrosslinking reaction of the pendant oxetane groups proceeded smoothly to give the insoluble polymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1952–1961, 2003     

Cobalt-Catalyzed E-Selective Cross-Dimerization of Terminal Alkynes: A Mechanism Involving Cobalt(0/II) Redox Cycles

A highly E-selective cross-dimerization of terminal alkynes with either terminal silylacetylenes, tert-butylacetylene, or 1-trimethylsilyloxy-1,1-diphenyl-2-propyne in the presence of a dichlorocobalt(II) complex bearing a sterically demanding 2,9-bis(2,4,6-triisopropylphenyl)-1,10-phenanthroline, activated with two equivalents of EtMgBr, gives a variety of (E)-1,3-enynes. A well-characterized diolefin/cobalt(0) complex, with divinyltetramethyldisiloxane, acted as a catalytically active species without any activation, clearly indicating that a cobalt(0) species is involved in the catalytic cycle.     

Responsive microstructures on organic–inorganic hybrid films

Micro-periodic structures exhibiting shape memory have been fabricated on organic–inorganic hybrid films. The microscale structures are obtained by forming wrinkles via buckling of the stiff surface layer. The surface-modified layers are obtained by surface photopolymerization or by oxidation of the hybrid films. The microscale structures are spontaneously formed by the shrinkage of the underlayer via gelation. The surface microstructures on titania- or silica-based films with hydrophilic swellable polymers exhibit a humidity response, i.e., a shape memory effect. This is observed when the surface microstructure disappears and is subsequently recovered with cyclic variation of the surrounding humidity. Micro-rolls are also fabricated by the selective swelling of surface-modified layers.     

Facile One‐Pot Synthesis of [1, 2, 3]Triazolo[1, 5‐a]Pyridines from 2‐Acylpyridines by Copper(II)‐Catalyzed Oxidative NN Bond Formation

An efficient and simple method for the synthesis of various [1, 2, 3]triazolo[1, 5‐a]pyridines has been established. The method involves a copper(II)‐catalyzed oxidative N?N bond formation that uses atmospheric oxygen as the terminal oxidant following hydrazonation in one pot. The use of ethyl acetate as the solvent dramatically promotes the oxidative N?N bond‐formation reaction and enables the application of oxidative cyclization in the efficient one‐pot reaction. A mechanism for the reaction was proposed on the basis of the results of a spectroscopic study.