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301.
Tadao Kanzaki 《Journal of Electron Spectroscopy and Related Phenomena》1990,50(2):309-321
At pH 7.0, lower crystalline iron (II) hydroxide, “green rust II” (the FeII:FeIII mol ratios and the electron diffraction measurements do not indicate the tendency for Zn2+ ion to be incorporated in place of the Fe2+ ion) and Zn-bearing ferrite are formed from aqueous iron (II) hydroxide suspensions containing the zinc (II) ion at a Zn: Fetot. mol ratio of 1.00:2.00. At pH 9.0 and 10.0, higher and lower crystalline iron (II) hydroxides and Zn-bearing ferrite are formed. The ratios of higher to lower crystalline iron (II) hydroxide are approximately constant during oxidation at pH 9.0. The oxidation reactions are divided into two classes according to the Zn: Fetot. mol ratios. At pH 7.0, lower crystalline iron (II) hydroxide is formed at the early stages of oxidation and dissolved iron (II) species are formed during the oxidation at a Zn:Fetot. mol ratio of 0.20:2.80. Iron (II) hydroxide is formed during oxidation and dissolved iron (II) species are formed at an early stage of the oxidation at Zn:Fetot. mol ratios of 0.60:2.40 and higher. At pH 9.0 and 10.0, both higher and lower crystalline iron (II) hydroxides are formed at Zn: Fetot. mol ratios of 0.60:2.40 and higher, and 1.00:2.00, respectively. However, at a Zn:Fetot. mol ratio of 0.20:2.80, iron (II) hydroxide with a large quadrupole splitting value and dissolved iron (II) species with large isomer shifts and quadrupole splitting values are formed before and during oxidation at pH 7.0, and the formation of Zn-bearing ferrite is depressed (-FeO(OH) is formed) at pH 10.0. 相似文献
302.
303.
Noboru Yamazaki Tadao Iguchi Fukuji Higashi 《Journal of polymer science. Part A, Polymer chemistry》1979,17(3):835-841
Selective formation of biscarbamates from diphenyl carbonate (DPC) and diamines and the preparation of polyurethanes from the carbamates and diols under mild conditions were studied. The reaction of DPC and diamines was significantly affected by catalysts, biscarbamates being exclusively prepared in high yields in the presence of 2-hydroxypyridine. The polycondensation reaction of the biscarbamates with diols was facilitated by catalysts such as metal salts; among the catalysts examined magnesium chloride in pyridine gave the best results. Metal chlorides in pyridine also promoted the reaction of DPC with aromatic amines to give the corresponding ureas, and the direct synthesis of polyureas was achieved by the polycondensation of DPC with diamines in the presence of the chloride. 相似文献
304.
305.
Takashi Kamitanaka Tatsuyoshi Hikida Nobuhiro Kishida Tadao Harada 《Tetrahedron letters》2007,48(48):8460-8463
The reactions of the alkenes with supercritical organic compounds under non-catalytic conditions were investigated. The H and CR2OH, CH2COCH3 or CH2CN of supercritical alcohols (CHR2OH), acetone (CH3COCH3) or acetonitrile (CH3CN) added to the CC bonds of alkenes form C-C bonds between the α-carbons of the supercritical organic compounds and the sp2 carbons of the alkenes. 相似文献
306.
Abstract The polymerization of vinyl monomers initiated by dimethylhydroxylamine hydrochloride (DHA)-titanous(III) chloride redox system has been studied in water under a nitrogen atmosphere. In the polymerization of methyl methyacrylate (MMA) initiated by the above system, the rate of polymerization has been found to be proportional to [DHA]0.5 for DHA concentrations of less than 2.06 × 10?3 mole/liter, whereas at higher concentrations the rate tends to fall rapidly. The rate has also been found to be proportional to [Ti(m)] 0.58 and to [MMA] 1.0. The maximum rate of polymerization has been observed at a 1:1 molar ratio of DHA to Ti(III). The polymerization proceeded via a radical mechanism. The overall activation energy was estimated as 5.5 kcal/mole. It has been suggested that the reduction of dimethylhydroxylamine by titanous(III) chloride yields the dimethylamino radical, which initiates vinyl polymerization. An examination of the initiating capacity of the initiator system for the polymerization of some vinyl monomers has also been made. 相似文献
307.
In the preceding papers of this series, we reported the synthesis of liquid-crystalline polyurethanes containing mesomorphic moieties in the main chain and in side chains [1–4]. Liquid crystalline polymers with side groups containing the cholesterol moiety have also been studied [5, 6]. The main focus of attention has centered around the study of phase transitions of acrylic and methacrylic derivatives of cholesterol. This paper describes the synthesis of a new type of liquid-crystalline polyurethane containing the cholesterol moiety in side chains. 相似文献
308.
Koji Nagata Tadao Nakamura Josep Batle Ahmed Farouk 《International Journal of Theoretical Physics》2018,57(10):3098-3103
Based on a particular mathematical structure of a certain function f(x) under our attention, we present a novel quantum algorithm. The algorithm allows one to determine the property of a certain function. In our study, it is f(x) = f(?x). Therefore, there would be a question here, “How fast can we succeed in this?” All we need to do is only the evaluation of a single quantum state \(|\overbrace {0,0,\ldots ,0,1}^{N}\rangle \) (N ≥?2). Only using that with a little amount of information, we can derive the global property f(x) = f(?x). Our quantum algorithm overcomes a classical counterpart by a factor of the order of 2N. 相似文献
309.
Koji Nagata Tadao Nakamura Josep Batle Soliman Abdalla Ahmed Farouk 《International Journal of Theoretical Physics》2018,57(7):2116-2120
In the short contribution, we consider inequalities of confirming genuine multipartite entanglement. We have a better entanglement witness for a particular mixed state to test genuine multipartite entanglement. Our physical situation is that we measure Pauli observables σ x , σ y , and σ z per side. If the reduction factor is greater than 0.4, then we can confirm the measured quantum state is genuine multipartite entangled experimentally. 相似文献
310.
Tadao Shibutani Hisashi Fujihara Naomichi Furukawa Shigeru Oae 《Heteroatom Chemistry》1991,2(5):521-531
Aryl 3- and 4-pyridyl sulfoxides undergo ligand exchange in reactions with aryl Grignard reagents to generate 3- and 4-pyridyl Grignard reagents, which, upon treatment with aldehydes or ketones, give the corresponding addition products in moderate-to-good yields. The mechanism for the exchange reaction was investigated by treating optically active 3- and 4-pyridyl p-tolyl sulfoxides with a phenyl Grignard reagent. Inversion of the configuration of the sulfur atom was the stereochemical result of the reactions. In the reactions of phenyl 2-pyridyl sulfoxide with Grignard reagents, the leaving ability of the 2-pyridyl group competes with that of the phenyl group. Both the experimental and MO calculated enthalpy values for deprotonation of α-, β-, and γ-protons of pyridine in the gas phase [1] are in accordance with the following order of the leaving abilities of aryl and pyridyl Grignard reagents: 4-PyMgBr > 3-PyMgBr » PhMgBr > p-TolMgBr > 2-PyMgBr. 相似文献