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1.
Tsutomu Nakanishi Hajime Okamoto Maki Kasahara Kyozaburo Takeda 《Journal of Polymer Science.Polymer Physics》2003,41(22):2829-2849
We theoretically investigated the polymorphy of the stereostructures of a periodic polymer. Using the polymer's internal conformation parameters of bond lengths, bond angles, and internal rotation angles, we extended the mathematical treatment for designing polymer backbones. We considered those periodic polymers whose unit cell consists of one (m = 1), two (m = 2), or three (m = 3) kinds of atoms. Moreover, for these three types of polymers, we supposed two catenation types for the skeleton atoms; one is a “homorotatory” sequence and the other is a “heterorotatory” one. To specify the backbone's stereostructure, we introduced several conformation parameters such as the helical pitch number n, the translation distance d, and the inclination angle of the skeleton plane Θ. By combining these parameters, we can systematically understand the variety and the possible polymorphy in the stereostructure of a periodic polymer backbone. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2829–2849, 2003 相似文献
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Tsutomu Oishi Kensoh Kagawa Minoru Fujimoto 《Journal of polymer science. Part A, Polymer chemistry》1995,33(8):1341-1352
Two types of optically active N-[N′-(α-methylbenzyl)amino/carbonyl-n-alkyl]maleimides (MBAC) were synthesized from maleic anhydride, 6-amino-n-caproic acid (or 12-amino-n-dodecanoic acid), and (R)-(+)-α-methylbenzylamine. Radical homopolymerizations of MBAC were performed in several solvents at 60 and 110°C for 24 h to give optically active polymers. Radical copolymerizations of MBAC were performed with styrene (ST) and methyl methacrylate (MMA) in dioxane at 60°C. The monomer reactivity ratios and the Alfrey-Price Q-e values were determined. Chiroptical properties of the polymers and copolymers were investigated. © 1995 John Wiley & Sons, Inc. 相似文献
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Yoshio Kato Katsuo Komiya Yuuzi Sawada Hiroo Sasaki Tsutomu Hashimoto 《Journal of chromatography. A》1980,190(2)
The purification of enzymes was investigated by high-speed gel filtration on TSK-GEL G3000SWG columns packed with porous silica gel deactivated by chemically bonded hydrophilic compounds. Crude β-galactosidase from bacterial cells and commercial urease were purified ca. 15-fold in a single gel filtration. These enzymes were eluted within an hour from the column and the recoveries of enzymatic activity were almost 100% although the operation was carried out at room temperature (22°). Samples up to 100 mg could be applied to the column without loss of separation efficiency. 相似文献
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The vertical ionization potentials of difluoramine are calculated by perturbation corrections to Koopmans' theorem. The calculation shows that difluoraimine has three overlapping bands between 15 and 16 eV. The calculated results compare well with the experimental values. The photoelectron spectrum of difluoramine is compared with that of OF2 and CH2F2. 相似文献
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Tsutomu Kagiya Masatsugu Izu Masakazu Hatta Takehisa Matsuda Kenichi Fukui 《Journal of polymer science. Part A, Polymer chemistry》1967,5(5):1129-1135
N,N′-Dipropionylethylenediamine was synthesized by the ring-opening addition reaction of 2-ethyl-2-imidazoline with propionic acid at 220°C. By applying this reaction to polymerization, polyamides were synthesized by the ring-opening polyaddition reaction at 220°C. of 1,4-bis(imidazoline-2-yl)butane with adipic acid, succinic acid, sebacic acid, and terephthalic acid. The reaction product of 1,4-bis(imidazoline-2-yl)butane with adipic acid, which was proposed to be nylon 26, was compared with an authentic sample of nylon 26 and shown to possess a very similar infrared spectrum and melting point. 相似文献
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The lattice image of the FeCr σ-phase was observed by high-resolution electron microscopy with the c axis of the tetragonal cell parallel to the incident beam. It was found that bright dots of the observed image correspond to the positions of atoms in the planes of the σ-phase structure. Sequence faults were found in the irregular part of the lattice image. The analysis of the faults shows that an extra plane of width is inserted into the regular structure and one side of the fault is slightly shifted parallel to the fault plane with respect to the other side, which is consistent with the model proposed by Frank and Kasper. A unit cell step of the sequence faults was found and a model of the step was proposed. 相似文献