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461.
In the presence of AgClO4, chloro(η5-cyclopentadienyl)(triphenylphosphine)palladium(II) was treated with triphenylphosphonium benzoylmethylid 相似文献
462.
463.
Naoki Oguri Akira Onishi Sigeki Uchino Keiji Nakahashi Nakamichi Yamasaki Xigao Jin 《Journal of separation science》1993,16(10):597-600
High speed hydrothermal decomposition of some chemically inert condensation polymers in alkaline solutions under near-critical pressures and temperatures has been investigated by on-line Curie-point heating–high resolution GC-MS. The technique also involves simultaneous methylation with tetramethylammonium hydroxide in a 1 mm i.d. × 20 mm sealed glass capillary. The relative standard deviation for the peak intensity (mol %) resulting from ten replicate measurements of poly(butylene terephthalate) is approximately 3%. This method requires a small amount of sample (ca. 0.1 mg) and provides simple chromatograms, greater structural information, good reproducibility, and rapid reaction (0.5–15 min) without chemical treatment. A brief overview of applications to the characterization of some condensation polymers such as aromatic polyester, polycarbonate, and aliphatic and aromatic polyamide is also described. 相似文献
464.
Robert J. Limhardt K. L. Carleton J. P. Rowland M. J. Daniels D. M. Farmer I. Ehrenthal K. E. Miner J. T. Johansen J. Maurukas G. T. McCollough T. W. Esders S. Y. Lynn I. E. Modrovich K. Oyama S. Nishimura Y. Nonaka T. Hashimoto K. Kihara A. Sakimae H. Onishi H. Schutt L. I. Stekolnikov B. A. Sevastyanov G. G. Shilov A. A. Belousov N. D. Mamonov 《Applied biochemistry and biotechnology》1986,12(1):67-76
465.
466.
Ground states of theX Y-model on infinite one-dimensional lattice, specified by the Hamiltonian $$---J\left[ {\sum {\left\{ {(1 + \gamma )\sigma _x^{(j)} \sigma _x^{(j)} + (1 - \gamma )\sigma _y^{(j)} \sigma _y^{(j + 1)} } \right\} + 2\lambda \sum {\sigma _z^{(j)} } } } \right]$$ with real parametersJ≠0,γ andλ, are all determined. The model has a unique ground state for |λ|≧1, as well as forγ=0, |λ|<1; it has two pure ground states (with a broken symmetry relative to the 180° rotation of all spins around thez-axis) for |λ|<1,γ≠0, except for the known Ising case ofλ=0, |λ|=1, for which there are two additional irreducible representations (soliton sectors) with infinitely many vectors giving rise to ground states. The ergodic property of ground states under the time evolution is proved for the uniqueness region of parameters, while it is shown to fail (even if the pure ground states are considered) in the case of non-uniqueness region of parameters. 相似文献
467.
Shuzi Hayase Yasunobu Onishi Shuichi Suzuki Moriyasu Wada 《Journal of polymer science. Part A, Polymer chemistry》1983,21(2):467-477
The activity of an aluminum complex/polysilanol polymerization catalyst was examined in order to confirm the dependence of catalytic activation on silanol chain length. Tris (acetylacetonato)–aluminum/silanol increased when silanols with an intramolecular hydrogen bond such as the trimer of diphenylsilanediol, polydiphenyl(4-vinylphenyl)silanol, and polymeric silanol of silicone were used. However, when tris(ethylacetoacetato)aluminum or tris(salicylaldehydato)aluminum was used, the product obtained from the reaction of a part of the aluminum complex with the polysilanols had to be considered in any explanation of the catalytic activation. The active catalyst with such aluminum complexes was obtained when the silanols that had intramolecular hydrogen bonds and gave the appropriate ratio of the reaction between the aluminum complex and silanol were used. 相似文献
468.
469.
The annulation method based on 2H-cyclohepta[b]furan-2-ones was applied for the synthesis of 2-alkylazulenes; 2-R-azulene (R = Et, i-Pr, n-Pr, i-Bu). Tropolone p-toluenesulfonate was used as a starting compound. By the two step synthesis, 1-carboxylic-3-cyanoazulene derivatives were obtained. Treatment of 1-carboxylic-3-cyanoazulene derivatives with aq H2SO4 resulted in decarboxylation and elimination of cyano group to give 2-alkylazulenes in good yields. 相似文献
470.
Procedures are given for the determination of traces of tin with dithiol (4-methyl-1,2-dimer-captobenzene) by visual color comparison and absorptiometric measurement, with special reference to silicate rocks, meteorites, and sulfides. The sensitivity is 1 p.p.m. Sn with 0.5 g of sample. Tin is separated by distillation of the bromide. Provision is made for the presence of selenium. 相似文献