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A 750 nm-thick PZT-PMN/PZT composite film was prepared by sequential multiple spin-coatings. First, a 375 nm-thick sol-gel Pb(Zr0.56Ti0.44)O3(PZT) layer was prepared on a Ti/Pt/Ti bottom electrode and then a 375 nm-thick Pb(Zr0.56Ti0.44)0.80(Mg1/3Nb2/3)0.20O3(PZT-PMN) layer was prepared on the PZT layer. The structural, compositional and piezoelectric properties of the composite film were investigated by using X-ray diffraction, scanning electron microscopy, cross-sectional transmission electron microscopy and secondary ion mass spectrometry and by measuring the piezoelectric charge constant d31, the piezoelectric voltage constant g31 and the relative permittivity ϵ. The composite film retains the tetragonal perovskite structure with columnar grains. The lattice of the PZT-PMN layer smoothly connects to that of the PZT layer without forming any interfacial structure. However, the atomic composition, mainly in Mg and Nb, differs between PZT-PMN and PZT layers. The composite film has a higher piezoelectric charge constant d31 as compared with the PZT-PMN and PZT single films. The value of d31 is independent of the sequence of the PZT-PMN and PZT layers.

Abstract: We conducted x-ray crystal truncation rod (CTR) measurements using synchro-tron radiation to analyze the As atom distribution in InP to the order of 1 ML. The InP samples which were only exposed to AsH3(+PH3) and capped by InP were investigated to study the effect of the purge sequence. The purge sequence is unavoidable to grow heteroepitaxial layers by OMVPE and is considered to affect largely the structure of the interface. From the results of the measurement and the computer simulation, the distribution of P and As atoms of the order of 1 ML was discussed as functions of the exposing time. It was shown that the number of As atoms contained in the samples saturated when the AsH3-exposure time is longer than 10 s. Comparing the profiles of AsH3-exposed samples with that of (AsH3 + PH3)-exposed samples, it was found that the As distribution in the buffer layer was suppressed in (AsH3 + PH3)-exposed samples. In order to obtain the sharp interfaces, the AsH3-exposure time must be shorter than 0.5 s.

The phase separation of a mesogen-nonmesogen mixture was studied with particular emphasis on the effects of boundary conditions imposed at container walls such as rubbed polyvinylalcohol (PVA) film, obliquely evaporated SiO film, free surface, etc. Microscopic observations revealed that the equilibrium shapes of a nematic or isotropic liquid formed on a substrate in the temperature range of isotropic-nematic coexistence vanes greatly depending on the nature of the substrate. Typically the contact angle of a nematic liquid formed at the isotropic-substrate interface is 0° on a rubbed PVA film and at the free surface, and is nearly 180° on an Sio film. The connection between the substrate induced ordering and the contact angle is discussed.

Pyrroloquinoline quinone (PQQ) inhibited the chemiluminescence (CL) from mouse peritoneal cells initiated by zymosan, carrageenin and N-formyl-methionyl-leucyl-phenylalanine and CL generated by the xanthine-xanthine oxidase reaction and the lipid peroxidation in the rat brain homogenate. The inhibitory activity of PQQ was more potent than that of idebenone, alpha-tocopherol and ascorbic acid in all the three assay systems. In the xanthine-xanthine oxidase reaction, PQQ had no effect on the formation of uric acid at the concentration of CL inhibition. These results suggest that PQQ might have a radical scavenger-like activity. Structure-activity relationship of PQQ and its six related compounds showed that the 7- and 9-carboxyl groups of PQQ as well as the orthoquinone structure are responsible for the radical scavenger-like activity. In addition, the -NH group in the pyrrole ring of PQQ seemed to be essential for the antilipid peroxidative activity in the rat brain homogenate. When administered i.p., PQQ inhibited the development of 0.1% carrageenin-induced paw edema in rats. These results suggest that PQQ might have therapeutic effects on various diseases, of which development or exacerbation has been known to be associated with radical oxygens.

A novel hydrophilic gold compound, tetrakis((trishydroxymethyl)phosphine)gold(I) chloride 1, has been investigated for its antitumor properties. In vitro studies demonstrate that 1 is active against HCT-15, AGS, PC-3, and LNCaP tumor cells. Cell cycle analysis of the HCT-15 cells by flow cytometry revealed elongation of the G1 phase of the cell cycle leading to growth inhibition. Administration of 1 to Balb/C mice inoculated with syngenic meth/A cells demonstrated statistically significant dose-dependent survival time.

To clarify the relationship between dislocation slip and hydrogen for elucidation of hydrogen embrittlement mechanism, the effect of hydrogen on dislocation slip was examined by comparing changes in the stress-strain curve and stress relaxation behavior with/without hydrogen charging. Tempered martensitic steel with the tensile stress of 1480 MPa was used. Hydrogen charging was conducted by the electrolysis charging. Tensile tests were conducted for hydrogen-charged specimens containing hydrogen from 0 to 5.6 mass ppm at strain rates from 1.83x10-5 to 1.83x10-2 s[?]1. In the stress-strain curve, the elastic modulus did not change, but the upper and lower yield points increased through charged hydrogen. The tensile strength increased and the work hardening rate did not change through charged hydrogen. The yield points and tensile strengths increased with increasing the amount of hydrogen. It suggests that hydrogen suppressed dislocation slip, that is, hydrogen caused hardening. Stress relaxation tests were conducted for hydrogen-charged specimens containing hydrogen from 0 to 4.7 mass ppm. Even though the amount of hydrogen increased, the amount of stress relaxation remained constant. Therefore, hydrogen probably did not promote the increase in dislocation density. These results reveal that hydrogen causes not softening but hardening.