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排序方式: 共有277条查询结果,搜索用时 15 毫秒
201.
Yoshinori Kamiya Takuji Hirose Keishin Mizoguchi Katsuhiko Terada 《Journal of Polymer Science.Polymer Physics》1988,26(7):1409-1424
Dilation of poly(vinyl benzoate) and poly(vinyl butyral) accompanying sorption of carbon dioxide is measured with a cathetometer under pressures up to 50 atm at 25°C. Sorption isotherms for carbon dioxide in these polymers were also determined gravimetrically. Each dilation isotherm plotted versus pressure, as well as the sorption isotherm, showed an inflection point corresponding to the glass transition of the polymer-gas system. The dilation isotherms changed their form at that point from concave to convex to the pressure axis or to a straight line. Dilation and sorption isotherms exhibited time-dependent hysteresis below the inflection point but not above the point. Partial molar volumes of carbon dioxide in polymers, which were determined from dilation and sorption data above the point, were found to be independent of concentration and larger than those below the point. The latter volumes depended on concentration. Based upon the extended dual-mode sorption concept, which takes account of plasticization of polymer by sorbed gas, a dilation model was developed. Dilation data were described well by the model. 相似文献
202.
Yoshinori Kamiya Keishin Mizoguchi Takuji Hirose Yasutoshi Naito 《Journal of Polymer Science.Polymer Physics》1989,27(4):879-892
Sorption and dilation in the system poly(ethyl methacrylate) (PEMA) and carbon dioxide are reported for pressures up to 50 atm over the temperature range 15–85°C. The sorption isotherms were obtained gravimetrically. The dilation accompanying sorption was measured directly with a cathetometer. At low temperatures the sorption and dilation isotherms were concave toward the pressure axis in the low-pressure region and turned to convex with increasing pressure. As the experimental temperature approached and exceeded the glass transition temperature of 61°C, both isotherms became convex or linear over the whole range of pressure. Partial molar volumes of CO2 in PEMA were obtained from sorption and dilation data, which were described well by the extended dual-mode sorption and dilation models developed recently. The temperature dependence of the dual-mode parameters and the isothermal glass transition are discussed. 相似文献
203.
Yoshinori Kamiya Takuji Hirose Yasutoshi Naito Keishin Mizoguchi 《Journal of Polymer Science.Polymer Physics》1988,26(1):159-177
Dilation of polysulfone (PSUL) and crystalline poly(ethylene terephthalate) (PET) films accompanying sorption of carbon dioxide is measured by a cathetometer under high pressure up to 50 atm over the temperature range of 35–65°C. Sorptive dilation isotherms of PSUL are concave and convex to the pressure and concentration axes, respectively, and both isotherms exhibit hysteresis. Each dilation isotherm plotted versus pressure and concentration for the CO2-PET system shows an inflection point, i.e., a glass transition point, at which the isotherm changes from a nonlinear curve to a straight line. Dilation isotherms of PET below the glass transition point are similar to those of the CO2-PSUL system, whereas the isotherms above the glass transition point are linear and exhibit no hysteresis. Partial molar volumes of CO2 in these polymers are determined from data of sorptive dilation. On the basis of the extended dual-mode sorption model and the current data, primitive equations for gas-sorptive dilation of glassy polymers are proposed. 相似文献
204.
The transport properties of vacuum evaporated selenium doped with small quantities of atoms (Li, Ga, In, Cl, etc.), and compounds (LiCl, GaF3, In2O3, etc.) are examined using time-of-flight technique. When doped with certain compounds (for example, GeO2), electrons and holes show comlex transport behavior different from the compensation effect due to co-doping of the component atoms (Ge, O). This suggests that these compounds are taken into selenium in the “molecular form”. 相似文献
205.
Magnetic form factor of the ordered Fe3Pt alloy was measured by means of the polarized neutron diffraction technique. From the form factor analysis, localized moments of Fe and Pt are determined as μFe = 2.03 ± 0.02 μB, μPt = 0.36 ± 0.08 μB at room temperature respectively. The fractional population of T2g levels for Fe atoms is also determined as 0.52 ± 0.02. 相似文献
206.
207.
Katsuhiko Terada Keishin Mizoguchi Takuji Hirose 《Journal of Polymer Science.Polymer Physics》1992,30(6):539-548
Permeation of eight gases (He, Ne, Ar, Kr, O2, N2, CO2, and CH4) in three isomeric poly(vinyl methylbenzoates) was measured by the time-lag method, and the effects of the shape of side groups on gas transport in the polymers were investigated. The p-methylphenyl side group of poly(vinyl p-methylbenzoate), which increases both interchain and intrachain distances, caused an increase in gas diffusivity. The diffusivity and density data were consistent with free volume theory. Two other isomeric polymers, poly(vinyl o-methylbenzoate) and poly(vinyl m-methylbenzoate), had lower gas diffusivities than poly(vinyl p-methylbenzoate) and poly(vinyl benzoate). The o-methyl and m-methyl groups on the phenyl ring were found to hinder gas diffusion, i.e., decrease the free volume. In contrast, the solubility of the gases in all these polymers was similar because of their similar chemical structures. The effects of hydroxyl groups also were investigated by the use of poly(vinyl m-methylbenzoate) containing a small number of vinyl alcohol units. The decrease in gas diffusivity was attributed to the decrease of free volume due to hydrogen bonding, but the change of gas solubility was still negligible. 相似文献
208.
Tatsuya Shono Yoshihiro Matsumura Jue Hayashi Mikiko Mizoguchi 《Tetrahedron letters》1980,21(19):1867-1870
The electrochemical oxidation of alcohols was accomplished by using a double mediatory system in which both alkyl methyl sulfide and bromide act in concert as mediators. 相似文献
209.
Katsuhiro Mizoguchi Tamotsu Kamiya Eishun Tsuchida Isao Shinohara 《Journal of polymer science. Part A, Polymer chemistry》1979,17(3):649-658
The electric properties of polymer composites with highly conductive 7,7,8,8-tetracyanoquinodimethan (TCNQ) salts such as quinolinium–TCNQ complex salt (), acridinium–TCNQ complex salt (), and N-methylacridinium–TCNQ complex salt () were studied. Polyacrylonitrile (PAN), poly(N-vinylcarbazole) (PVK), and poly(4-vinylpyridine), (P4VP), etc., were chosen as matrix polymers. The resistivity (ρ) of the was 0.37 Ω cm at the content of 20 wt % in the film. When the content of was increased up to 40 wt%, a phase separation of the needle crystals was observed and the ρ value increased. When was dispersed into PAN or PVK, the separation was also observed and the samples showed low conductivity. The uniform films were obtained in the and systems, but the values of ρ were high because of the degradation of the TCNQ salts. Uniform films with the naked eye were obtained in the and systems, and the values of Ω were 0.37, 1.05, and 3.40 Ω cm, respectively. was stable even when dispersed into P4VP. The properties of the composites were influenced by the combination of the TCNQ salts and the polymers. The uniformity and the stability of the composites were necessary to obtain the high conductive composites. 相似文献
210.
Takayama K Koseki K Torikai K Tokuchi A Nakamura E Arakida Y Shimosaki Y Wake M Kouno T Horioka K Igarashi S Iwashita T Kawasaki A Kishiro J Sakuda M Sato H Shiho M Shirakata M Sueno T Toyama T Watanabe M Yamane I 《Physical review letters》2005,94(14):144801
A single rf bunch in the KEK proton synchrotron was accelerated with an induction acceleration method from the injection energy of 500 MeV to 5 GeV. 相似文献