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381.
Fuji Funabiki Tetsuji Yano Shuichi Shibata Masayuki Yamane 《Solid State Ionics》2003,160(3-4):281-288
The Ag2O–TiO2–SiO2 glasses were prepared by Ag+/Na+ ion-exchange method from Na2O–TiO2–SiO2 glasses at 380–450 °C below their glass transition temperatures (Tg), and their electrical conductivities were investigated as functions of TiO2 content and the ion-exchange ratio (Ag/(Ag+Na)). In a series of glasses 20R2O·xTiO2·(80−x)SiO2 with x=10, 20, 30 and 40 in mol%, the electrical conductivities at 200 °C of the fully ion-exchanged glasses of R=Ag were in the order of 10−5 or 10−4 S cm−1 and were 1 or 2 orders of magnitude higher than those of the initial glasses of R=Na. The glass of x=30 exhibited the highest increase of conductivity from 3.8×10−7 to 1.3×10−4 S cm−1 at 200 °C by Ag+/Na+ ion exchange among them. When the ion-exchange ratio was changed in 20R2O·30TiO2·50SiO2 system, the electrical conductivity at 200 °C exhibited a minimum value of 7.6×10−8 S cm−1 around Ag/(Ag+Na)=0.3 and increased steeply in the region of Ag/(Ag+Na)=0.5–1.0. When the ion-exchange temperature was changed from 450 to 400 °C, the conductivity of the ion-exchanged glass of x=30 decreased. The infrared spectroscopy measurement revealed that the ion-exchange temperature of 450 °C induced a structural change in the glass of x=30. The Tg of the fully ion-exchanged glass of x=30 was 498 °C. It was suggested that the incorporated silver ions changed the average coordination number of titanium ions to form higher ion-conducting pathway and resulted in high conductivity in the titanosilicate glasses. 相似文献
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Hideshi Nakamura Houming Wu Yasushi Ohizumi Yoshimasa Hirata 《Tetrahedron letters》1984,25(28):2989-2992
Agelasine-A, -B, -C and -D, novel bicyclic diterpenoids having inhibitory effects on enzymic reactions of Na,K-ATPase, have been isolated from the orange colored Okinawan sea sponge sp. and the structures have been determined on the basis of their spectral data and chemical conversions. 相似文献
386.
S. Shibata K. Miyajima H. Yoshikawa T. Yano M. Yamane 《Journal of Sol-Gel Science and Technology》2000,19(1-3):665-669
The formation of cellular patterns, known as Bénard cell, was investigated in organic-inorganic hybrid films under various conditions. The cells were observed in undoped-hybrid films, and its origin was attributed to the convection of TiO2 nanoparticles formed in the aging process of the sol. These cells showed the particular properties such as the difference between the center and its surrounding: the center showed a lower refractive index than that of the surrounding, a valley at the center with mountain-like surroundings, and a hydrophobic center and hydrophilic surrounding. How the cell patterns were formed depended on the conditions such as the atmospheric humidity and the gravity. It should be also noted that the cells on a silica glass substrate remained after 1000°C heating. 相似文献
387.
Young Sook Yun Yukari Takeda Haruhiko Fukaya Hiroyuki Fuchino Nobuo Kawahara Shigeru Takahashi Yuji Takahashi Hideshi Inoue 《Tetrahedron letters》2018,59(29):2813-2815
A new highly oxidized ent-norabietane diterpenoid named lathyrisol A (1) was isolated from roots of Euphorbia lathyris L. The structure and absolute configuration of 1 were elucidated on the basis of data obtained by HRESIMS, NMR, and the Cu-Kα radiation X-ray diffraction analysis. This compound is the first example of naturally occurring norabietane diterpenoid with an exocyclic olefin at the C-4 position. 相似文献
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