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111.
The behavior of hydrogen in glow-discharge (GD) μc-Si:H has been characterized by 1H NMR. The 1H spectra consist of two components with different linewidths. The linewidth (FWHM) of the narrow component is about 0.5 kHz at ν0 = 90 MHz, being much narrower than has been observed in GD a-Si:H deposited under a conventional low RF-power condition. It has been demonstrated that the 0.5-kHz FWHM component originates from the hydrogens in motional narrowing state, and such fast-moving hydrogens are incorporated both in μc-Si:H and high-power deposited a-Si:H. 相似文献
112.
113.
Shinichi Yano Kenji Tadano Koichiro Aoki Naokazu Koizumi 《Journal of Polymer Science.Polymer Physics》1974,12(9):1875-1887
Dielectric properties of poly(vinylidene fluoride) have been studied in the frequency range 20 Hz to 1 MHz and between 100 and 220°C, during heating and cooling. The dielectric constant and loss change abruptly at the temperature Tm corresponding to the melting point. At lower frequencies, two types of ionic conductin are observed. One appears below Tm and is attributed to interfacial polarization. The other occurs above Tm and is related to electrode polarization. These results suggest that a crystalline polymer is a heterogeneous medium for ionic transport, while the melt is a homogeneous medium. From these results, the nature of ac ionic conduction in crystalline polymers is discussed. At high frequency, the α relaxation is observed below Tm. It is due to the molecular motion in the crystalline region and disappears at Tm. 相似文献
114.
115.
116.
Summary We give the fibre structure to the two complementary distributions, one being holomonic and the other being in general non-holomonic,
by assigning the structure preserving transformations of the coordinates and of the frames. By the conversion from such fibred
spaces we derive the spaces of non-linear connections as their image, in which we point out that the usual conditions imposed
on Ckji and the covariant differentiation of gji in the metric spaces of non-linear connections can be interpreted respectively as the parallel and isometric conditions imposed
on the fibre of the corresponding fibred Riemannian spaces.
To Enrico Bompiani on his scientific Jubilee. 相似文献
117.
Summary We start from a tensor field Q of type (1, 1) defined in a2n-dimensional manifold M which satisfies Q
2=0 and has rank n. The tensor field Q defines an almost tangent structure in M. We then introduce another tensor field P of
the same type and having properties similar to those of Q. We then define and study the tensors H=PQ, V=QP, J=P−Q, K=P+Q,
L=PQ−QP, (J, K, L) defining an almost quaternion structure of the second kind on M. We study the differential geometry on
almost tangent manifolds in terms of these tensors.
To ProfessorBeniamino Segre on his seventieth birthday
Entrata in Redazione il 7 giugno 1973. 相似文献
118.
Dynamic mechanical and dielectric properties of various kinds of polystyrene, including bulk-polymerized, monodisperse, isotactic, and thermally degraded samples, have been measured below the glass temperature to 4°K. Five relaxation processes are found, designated β, γ, γ′, δ, and ε in order of descending temperature. The β peak (350°K at 10 kHz) is attributed to the local oscillation mode of backbone chains and the γ′ peak (180°K at 10 kHz) to rotation of phenyl groups. The δ peak (100°K at 10 kHz) is observed only in dielectric properties of the bulk-polymerized sample and is assigned to weak polar bonds, such as oxygen bonds in the chain. The δ peak (55°K at 10 kHz) which is prominent in dynamic mechanical properties is interpreted in terms of lattice defects due to a syndiotactic diad inserted between isotactic sequences in a chain or vice versa. The ε peak (ca. 25°K at 10 kHz) is first reported in the present work, but the mechanism involved is not yet clear. 相似文献
119.
Shigeru Yabumoto Kiyoshi Ishii Masakiyo Kawamori Koichiro Arita Hiroshi Yano 《Journal of polymer science. Part A, Polymer chemistry》1969,7(7):1683-1696
The properties of the acrylonitrile–styrene copolymer prepared in the presence of zinc chloride were investigated in comparison with those of a copolymer having the same overall composition and prepared by the ordinary radical procedure. The characteristics of the polymer prepared with ZnCl2 were as follows: (1) less coloration by alkali treatment, (2) less coloration by thermal treatment and (3) higher glass transition temperature. These features may be attributed principally to the structure of the copolymer, which has more unlike bonds and less long sequences as described in the first article of this series. The effects of residual salt in the copolymer on the properties were also investigated. 相似文献
120.
Kazuhiro Taguchi Shoichiro Yano Kazuhisa Hiratani Norihiko Minoura 《Journal of Polymer Science.Polymer Physics》1993,31(3):339-345
The permeability of oxygen through horizontally oriented multibilayer films of polyion complexes prepared from quaternary ammonium-type surfactants [CH3(CH2)n-1]2N+(CH3)2Br?(n = 14, 16, 18), and poly(p-styrenesulfonate) or poly[2-(acrylamido)-2-methyl-1-propanesulfonate], was measured in water using an oxygen electrode. The permeability depended mainly on the phase of the multibilayers. Thus, it increased abruptly (about 10-fold) near each phase transition temperature because of the fluidity enhancement of the multibilayer. Inverted hexagonal type nonbilayer films prepared from the polyion complexes and cholesterol had greater permeability (2–20-fold) than the multibilayer films in both phases. The large permeability of the nonbilayer films was attributed to the lack of a barrier such as the bilayer and lower crystallinity of the films. It was associated neither with an increase in thermal movement of the lipid surfactant molecules nor with an increase in the water content of the films by the addition of cholesterol. © 1993 John Wiley & Sons, Inc. 相似文献