The characteristics of switching of millimeter wave energy are theoretically considered using a simple model of a YBa₂Cu₃O_7-x superconducting film. In the superconducting state, the transmission of electromagnetic wave through a superconducting film is determined by the London penetration depth. While, in the normal conducting state, it is determined by the classical skin depth, which is larger than the London penetration depth. Thus, the superconducting films may be applicable to microwave or millimeter wave switching. If the transition from superconducting to normal conducting state of the film, which is installed in a millimeter wave cavity, is performed at high speed, the energy stored in the cavity may be released to the output circuit as a pulse. The transmission coefficients of the YBa₂Cu₃O_7-x film are calculated and the output powers from a millimeter wave cavity are numerically analyzed. The peak output powers depend on the film thickness as well as on the unloaded quality factor of the cavity.

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Since the discovery of the new high Tc superconductor, various kinds of film growth technique have been reported on fabrication of an oxide superconducting film, especially YBCO and BSCCO above liquid nitrogen temperature. All of the techniques require the so-called post-growth heat treatment or a heating of the substrate during the deposition in order to grow an adequate polycrystal which can realize the superconducting state in the oxide. Such a heating process, however, yields some intermediate products at a boundary layer between the starting materials and the substrate, and the products result in degradation of the superconducting property.
In this paper, the annealing effect on the growth of YBCO or BSCCO oxide superconducting film and the substrate is investigated by using EDX analysis and SEM examination. In order to enhance the annealing effect, relatively thin YBCO and BSCCO films are fabricated with the starting materials pasted on substrates, and used rather than sputtered thin films for the analysis. MgO, Al₂O₃, SrTiO₃, 5% or 8% Y stabilized ZrO₂ (YTZ or YSZ) and so on are chosen as a substrate.
The results show that the heat treatment yields Ba compounds between YBCO and the substrates and Sr and Bi compounds between BSCCO and the substrates. Since the produced boundary layer of the intermediate product is the thinnest, MgO substrate can be recommended for YBCO film, and SrTiO₃ substrate for BSCCO film.

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High-T_c superconducting Y-Ba-Cu-O films were prepared on some ceramic and metal substrates by pyrolisis of 2-etylhexanoates.
Only the films on MgO, yttria-stabilized zirconia (YSZ), Ag substrates showed the superconducting transition above liquid nitrogen temperature.
Transition temperature values (T_c) of films on MgO, YSZ, and Ag substrates were observed at 82K, 85K, and 82K respectively.
The important factors to prepare superconducting films on substrates are the reactivity and the difference of thermal expansion between films and substrates. And that of Y-Ba-Cu-O for MgO, YSZ, and Ag was quite appropriate.
In this process we were using a Ag tape for producting long superconducting tape and currently the flexible tape with J_c=3×10³A/cm² (at 77K) was obtained.

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The experiments were carried out under the needle-plane electrode with small gap, filled with SF₆ or CCl₂F₂ gas. The voltage-time characteristics of the corona onset and breakdown in these gases were measured using μs pulse voltage of varoius wave fronts. Although the corona onset voltage decreased with increasing wave front, the breakdown voltage in some gap conditions reached a maximum value as the wave front increased, and then reduced at longer wave fronts. So, the shape of V-t characteristics was different from that case seen in usual gas such as N₂.
A polarity effect was also seen on the breakdown characteristics. These anomalous breakdown characteristics were discussed joining the results of the corona properties observed with an image intensifier tube.

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The reversible color phase transitions between the blue phase and the red phase caused by annealing have been reported for Langmuir-Blodgett polydiacetylene (LB PDA) films. We have already proposed an application of the LB PDA films to optical devices. In this paper, the reversible color phase transitions are investigated for the LB PDA films, that are pre-annealed before polymerization in order to improve the characteristics of the films. Absorption spectra of the LB PDA films without pre-annealing have main peaks at 640nm, while the spectra of the preannealed films have new main peaks at 704nm. The new peaks at 704nm exhibit stronger reversibility of the color phase transition than the peaks at 640nm. Moreover, X-ray diffraction measurements show that the pre-annealed LB PDA films have extremely ordered layer structures. Pre-annealing is thought to be an important technique for improving characteristics of LB films.

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We report the crystal structures and the superconductivity of the TlSr₂Ca_1-xY_xCu₂O₇ system. In the entire range of x=0-1, we could obtain single phase specimens. Each structure of TlSr₂Ca1-x Y_xCu₂O₇ (x=0-1) was similar to that of TlBa₂CaCu₂O₇ (so-called"1212"structure). With increas- ing x, the a-axis lengthened from 3.785A to 3.815Ä while the c-axis shortened from 12.104A to 11.978A, and the atom positions a little changed: i. e, oxygen atoms were drawn to Y/Ca atoms, however the positions of metal atoms did not change. The normal state conductivity decreases, with increasing x, the temperature dependencies of the resistivities of TlSr₂Ca_1-xY_xCu₂O₇ change from metal-like and not superconducting through metal-like and superconducting, semiconducting and superconducting to semiconducting and not superconducting. When the x values were 0.2, 0.4 and 0.6, they were superconductors with T_c (onset) of about 80K. In case of x=0, the mean Cu-valence is 2.5, and appears to be too large for superconductivity in this system (the mean Cu-valence was calculated assuming the oxygen and the all metal ion sites to be fully occupied). The valence of 2.2-2.4 (x=0.2-0.6) may be good for super conductivity, 2.0 or 2.1 (x=1.0, 0.8) is too small.

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The high temperature thermal cyclic degradation of the resin impregnated enamel insulations shows similar degradation characteristics to thermal degradation. As the maximum temperature in the thermal cycles T_m becomes higher, the degradation progresses faster. The relationship between the reciprocal absolute temperature of T_m and the logarithmus of the life can be expressed by a straight line, if T_m does not lie in the region of glass transition temperature T_g of the enamel or impregnated resin.
The thermal cyclic degradation progresses not due to the thermal degradation, but mainly due to cracks generated by the fatigue owing to repetition of the thermal stress based on the difference of the thermal expansion coefficients of the materials which constitute the resin impregnated enamel insulation.
In the insulation inferior in the thermal cyclic degradation, cracks originated from impregnated resin penetrate easily into the enamel layer. Once the enamel layer is broken through to the conductor, the conductor in the vicinity of the broken point is starting to erode, resulting in acceleration in the degradation.

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