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201.
202.
Kazuo Yamaura Kohsei Hirata Satoko Tamura Shuji Matsuzawa 《Journal of Polymer Science.Polymer Physics》1985,23(8):1703-1712
The dilute-solution behavior of poly(vinyl alcohol) (PVAVTFA), derived from vinyl trifluoroacetate, in water-dimethylsulfoxide (DMSO) mixtures was investigated. With solvent mixtures ranging from 10 to 20 vol % DMSO, the relation between the reduced viscosity ηsp/C and the polymer concentration C was linear for polymer concentrations above 0.2 g/dL, whereas in solutions in mixed solvents of other compositions the dependence was linear for polymer concentrations above 0.1 g/dL. The relation between the intrinsic viscosity [η] obtained for aqueous solutions of PVAVTFA and the molecular weight M estimated from viscosity measurements in solutions of poly(vinyl acetate) (PVAVTFA), obtained by acetylation of PVAVTFA, was given by [η] = 7.34 × 10?4 M0.63. The value of [η] was greatest for the solvent mixture with 10 vol % DMSO and smallest for about 50 vol % DMSO, and Huggins constants k were smallest and greatest for these two cases, respectively. The turbidity of the solutions of low-molecular-weight PVAVTFA, was higher than that of high-molecular-weight PVAVTFA up to 30 vol % DMSO, and the reverse relation held for 40-70 vol % DMSO. 相似文献
203.
204.
Yoshiaki Hamada Masamichi Tsuboi Takahiro Matsuzawa Kaoru Yamanouchi Kozo Kuchitsu Yoshihiro Koga Shigeo Kondo 《Journal of Molecular Spectroscopy》1984,105(2):453-464
Infrared absorption spectrum of allylimine in the gas phase was measured for the first time. The spectrum consisted of two rotational isomers, cis and trans, around the CC bond. The relative population of the trans form was 70–80%, and the rest was for the cis form at room temperature. This intermediate molecule was produced by the thermal decomposition of diallylamine and by the isomerization of propargylamine. The vibrational assignments were made with the help of an ab initio MO calculation. The half-life in the absorption cell was about 20 min. 相似文献
205.
Weak Weyl representations of the canonical commutation relation (CCR) with one degree of freedom are considered in relation
to the theory of time operator in quantum mechanics. It is proven that there exists a general structure through which a weak
Weyl representation can be constructed from a given weak Weyl representation. As a corollary, it is shown that a Weyl representation
of the CCR can be constructed from a weak Weyl representation which satisfies some additional property. Some examples are
given.
The work is supported by the Grant-in-Aid No.17340032 for Scientific Research from Japan Society for the Promotion of Science
(JSPS). 相似文献
206.
Yuji Matsuzawa 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2010,86(2):131-141
Although obesity is a major background of life style-related diseases such as diabetes mellitus, lipid disorder, hypertension and cardiovascular disease, the extent of whole body fat accumulation does not necessarily the determinant for the occurrence of these diseases. We developed the method for body fat analysis using CT scan and established the concept of visceral fat obesity, in other word metabolic syndrome in which intra-abdominal visceral fat accumulation has an important role in the development of diabetes, lipid disorder, hypertension and atherosclerosis. In order to clarify the mechanism that visceral fat accumulation causes metabolic and cardiovascular diseases, we have analyzed gene expression profile in subcutaneous adipose tissue and visceral adipose tissue. From the analysis, we found that adipose tissue, especially visceral adipose tissue expressed abundantly the genes encoding bioactive substances such as cytokines, growth factors and complements. In addition to known bioactive substances, we found a novel collagen-like protein which we named adiponectin. Adiponectin is present in plasma at a very high concentration and is inversely associated with visceral fat accumulation. Adiponectin has anti-diabetic, anti-hypertensive and anti-atherogenic properties and recent studies revealed that this protein has an anti-inflammatory and anti-oncogenic function. Therefore hypoadiponectinemia induced by visceral fat accumulation should become a strong risk factor for metabolic and cardiovascular diseases and also some kinds of cancers.In this review article, I would like to discuss the mechanism of life style-related diseases by focusing on the dysregulation of adiponectin related to obesity, especially visceral obesity. 相似文献
207.
Hideyuki Higashimura Kiyoshi Fujisawa Yoshihiko Moro‐oka Shuhei Namekawa Masaaki Kubota Akinobu Shiga Hiroshi Uyama Shiro Kobayashi 《Macromolecular rapid communications》2000,21(16):1121-1124
New heat‐reversibly crystalline poly‐(alkylated phenylene oxide)s are described. the oxidative polymerization of 2,5‐dimethylphenol catalyzed by (1,4,7‐triisopropyl‐1,4,7‐triazacyclononane) copper dichloride produced poly(2,5‐dimethyl‐1,4‐phenylene oxide), which showed heat‐reversible crystallinity with a high melting point at ca. 300°C, although the isomeric polymer, poly(2,6‐dimethyl‐1,4‐phenylene oxide), never recrystallizes once melted. The polymerization of 2,5‐diethylphenol and 2,5‐dipropylphenol gave the polymers consisting of 1,4‐phenylene oxide units; the latter polymer possessed heat‐reversible crystallinity, however, the former one did not. 相似文献