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901.
902.
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
903.
Kiyoaki Kobayashi Takasuke Matsuo Hiroshi Suga Slimane Khairoun Alain Tressaud 《Solid State Communications》1985,53(8):719-722
Heat capacity of ammonium hexafluorovanadate (NH4)3 [VF6] has been measured with a miniaturized adiabatic calorimeter from 20 to 300 K. A phase transition was found at 280.44 ± 0.05 K with the associated entropy change Δtrs S = 24.9 ± 0.5 JK?1 mol?1. The entropy transition is accounted for by the orientational order-disorder changes of hexafluorovanadate ion and ammonium ion occupying respective octahedral sites, as in the cases of (NH4)3AlF6 and (NH4)3FeF6 crystals. Changes in infrared spectra relative to v3 vibrational mode of [VF6]3? ion can be explained by an orientational disorder of the anions in the high-temperature phase (HTP). The dependence of cubic root of the unit-cell volume of a family of ammonium cryolites on their transition temperatures is discussed in relation to the nature of interactions which induce the phase transition. 相似文献
904.
Hiroshi Tamura 《Communications in Mathematical Physics》1985,98(3):355-367
A new type of regularized determinant for the ratio of two Dirac operators is presented. Some of its properties with application to the chiral anomaly are given. 相似文献
905.
Kazuhide Saigo Kazuo Tateishi Hiroshi Adachi 《Journal of polymer science. Part A, Polymer chemistry》1988,26(8):2085-2097
The radical polymerizations of diallylsilanes such as diallyldimethylsilane ( 1 ) and diallylmethylphenylsilane ( 2 ) have been conducted. Both poly(diallyldimethylsilane) ( 3 ) and poly(diallylmethylphenylsilane) ( 4 ) are soluble in benzene, methyl ethyl keton (MEK), and chloroform, slightly soluble in acetone, and insoluble in methanol and ethanol. No insoluble fraction of either polymer was obtained. Very little evidence of vinyl protons in the 1H-NMR spectra can indicate that both polymerizations predominantly proceed with intramolecular cyclization. In order to study the ring size of cyclic structure in the repeating unit of the polymers, a model compound, allyl(2-chloropropyl)dimethylsilane ( 5 ), was synthesized and cyclized with Bu3SnH in the presence of azobisisobutyronitrile (AIBN) in benzene, under similar condition of those for the cyclopolymerizations. The product was analyzed with GC–MS which showed that the five-membered ring compound, 1,1,3,4-tetramethylsilacyclopentane, was not formed. From the result of the cyclization of the model compound, it can be suggested that the polymerizations undergo with only h–t intramolecular cyclization to form a six-membered ring in the repeated unit. The 13C-NMR spectra of 3 and 4 were measured to study the ring size and the configuration of the cyclic structures. The two peaks at ?1.6 and ?3.4 ppm of the spectrum of 3 show that there are two kinds of methyl carbons in the repeating unit. From consideration of the model reaction and the number of the peaks of the NMR spectrum, it can be considered that the polymer main chain is assembled with the six-membered ring in cis-form, and the two signals are assigned to equatorial and axial methyl carbons, respectively. The two peaks at -1.5 and -5.1 ppm of the 13C-NMR spectrum of 4 can be assigned similarly. The radical cyclopolymerizations of triallylsilanes such as methyltriallylsilane ( 6 ) and phenyltriallylsilane ( 7 ) were conducted. The 1H-NMR spectra of poly(methyltriallylsilane) ( 8 ) and poly(phenyltriallylsilane) ( 9 ) show broad peak around 5 ppm for vinyl protons and around 2 ppm for alkyl protons. Comparisons of the relative intensities of the peaks indicate that both polymerizations undergo with single ring closure to form a polymer with monocyclic structure moiety, cyclosilahexane, and an allyl group in a repeating unit of 8 and 9 . 相似文献
906.
Ola Claesson Masaaki Ogasawara Hiroshi Yoshida Anders Lund 《Chemical physics letters》1983,94(4):408-410
Crystalline 1.8-octanediol has been γ-irradiated and its optical absorption spectrum has been measured at 4.2 K. The spectrum consists of three partially resolved peaks with maxima at 740, 590, and 490 nm. The peaks cannot be separated by photobleaching or annealing. It is suggested that they arise from transitions inherent in each localized electron. 相似文献
907.
Kang-Sin Choi Tatsuo Kobayashi Ryosuke Maruyama Masaki Murata Yuichiro Nakai Hiroshi Ohki Manabu Sakai 《The European Physical Journal C - Particles and Fields》2010,67(1-2):273-282
We study 10D super Yang–Mills theory with the gauge groups E 6, E 7 and E 8. We consider the torus/orbifold compactification with magnetic fluxes and Wilson lines. They lead to 4D interesting models with three families of quarks and leptons, whose profiles in extra dimensions are quasi-localized because of magnetic fluxes. 相似文献
908.
Hiroshi Matsuda 《Proceedings of the American Mathematical Society》2006,134(12):3697-3702
We study a relationship between arc presentations of links in and Legendrian links in with the standard tight contact structure. We determine the arc indices of torus knots.
909.
For a given map
defined on the field
of p-adic numbers satisfying
for some integer r, a Markov process on
induced by the map ϕ is constructed in (Kaneko and Zhao (1994) Forum Math. J. 16, 69). This approach can still be our choice in constructing a Markov process on finite algebraic extension of
. We will give an answer to the question as to how Markov process driven by set of maps will be addressed. Especially, we will focus on case the maps are given by the elements of Galois group of the extension. 相似文献
910.
Two new sesquiterpenes, 1S*, 4R*, 5S*, 6R*, 7S*, 10S*-1(5), 6(7)-diepoxy-4-guaiol (1) and 1S*, 4S*, 5S*, 10R*-4,10-guaianediol (2) have been isolated from the ethyl acetate soluble portion of the soft coral Sinularia sp., and their stereostructure were determined by spectroscopic methods and by X-ray single crystal analysis. Both compounds showed antioxidant and cytotoxic activities. 相似文献