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101.
The Spiro compound N3P3(OCH2CF3)4(NH)2Si(CH3)2 formed by reaction of 1,1-diamino-3,3,5,5-tetrakis(2,2,2-trifluoroethoxy)cyclotriphosphazene N3P3(OCH2CF3)4(NH2)2 and dimethyldichlorosilane Cl2Si(CH3)2 is a yellow or orange coloured oil soluble in organic solvents, vapourized at 160°C without decomposition, and not hydrolysed appreciably in boiling water. Linear compounds are formed by reaction of N3P3(OCH2CF3)4(NH2)2 with diphenyldichlorosilane or phenyltrichlorosilane owing to hindrance of the phenyl radical. These compounds are amorphous or tacky solids, soluble in organic solvents and stable to water. 相似文献
102.
Retardation of volatile aldehyde formation in the exhaust of frying oil by heating under low oxygen atmospheres 总被引:2,自引:0,他引:2
Mariko?Fujisaki Yasushi?Endo Kenshiro?FujimotoEmail author 《Journal of the American Oil Chemists' Society》2002,79(9):909-914
Volatile aldehydes were generated in the exhaust of high-oleic safflower oil during heating at 180°C by spraying water into
atmospheres with four levels of oxygen concentrations (2, 4, 10, and 20%). These aldehydes were quantitatively analyzed by
HPLC after the conversion to 2,4-dinitrophenyl hydrazones. Ten alkanals (C2 through C10), eight 2-alkenals (C3 through C10) and three 2,4-alkadienals (C7, C9, and C10) were found. These aldehyde levels were found to be positively correlated with both the heating time and the atmospheric
oxygen concentration. The total amounts of aldehydes were the lowest in the oil heated in an atmosphere with 2% O2, and corresponded to 1/10 of those in the atmosphere with 20% O2. Acrolein was not found in oils heated in the atmosphere with 2% oxygen. These results suggest that frying in atmospheres
with low oxygen levels can effectively decrease the generation of volatile aldehydes in the exhaust. 相似文献
103.
X.D. Yang T. Saito Y. Nakamura Y. Kondo N. Ohtake 《Diamond and Related Materials》2004,13(11-12):1984
Diamond-like carbon (DLC) films are metastable amorphous carbon materials with superior tribological characteristics. In order to improve wear resistance of micro-extrusion dies with numerous imperceptible holes, DLC films were deposited on the inner wall surface of model dies with holes of 2 and 0.9 mm in diameter, and 20 mm in depth by using pulse plasma CVD method. This paper will discuss how argon gas, deposition pressure and time affect the characteristics of films deposited on the inner wall surface of dies. This micro-coating method can be applied widely for inner wall surface treatment of components with thin holes. 相似文献
104.
The diffusion of a reactive disperse dye with a vinylsulfonyl group accompanied by simultaneous reaction with the amino end groups in nylon 6 was examined by the method of cylindrical film roll at 70°C and pH 2.2–8.0. The experimental diffusion profiles of the active and fixed species of the dye in nylon 6 were confirmed to be described by the diffusion equation accompanied by the chemical reaction with substrate taking the limited amount of the end groups into account, where the active species of dye were assumed to react only with the free base of amino end groups. The completion of the reaction with the amino end groups was observed in the first layer from the surface at pH 6.0–8.0. The value of diffusion coefficient was constant (8.0 × 10?10 cm2/s) at all the pH's. The product of the second-order rate constant, k2, of reaction of the dye and the dissociation constant, Ka, of the amino end groups was constant (k2Ka = 4.0 × 10?9 s?1) at pH 2.2–8.0. The k2 values of the reaction with various substrates for vinylsulfonyl and monochlorotriazinyl-reactive dyes were compared and the practical dyeing conditions were discussed. 相似文献
105.
Yujiro Watanabe Yusuke Moriyoshi Yasushi Suetsugu Toshiyuki Ikoma Takeshi Kasama Tadashi Hashimoto Hirohisa Yamada Junzo Tanaka 《Journal of the American Ceramic Society》2004,87(7):1395-1397
Type-A zeolite evenly covered with hydroxyapatite thin layers was prepared using hydrothermal treatment at 120°C for 8 h under autogenous pressure. The hydroxyapatite needlelike nanocrystals, 100–200 nm in diameter and 30 nm in thickness, were grown under the reaction between discharged Ca2+ ions from type-A zeolite and PO4 3− ions in (NH4 )3 PO4 solution. The preferential orientations of the c -axis of hydroxyapatite crystals perpendicular to a zeolite surface were observed using transmission electron microscopy. The crystal structure of type-A zeolite was not destroyed under the reaction, but the surface morphology was changed only with complete covering of scaly hydroxyapatite particles. 相似文献
106.
Satoru Sano Noriko Saito Shin-ichi Matsuda Naoki Ohashi Hajime Haneda You Arita Minoru Takemoto 《Journal of the American Ceramic Society》2006,89(2):568-574
Forsterite (Mg2 SiO4 ) ceramics were prepared using Mg(OH)2 and SiO2 as precursors, and the effect of powder characteristics of Mg(OH)2 on calcination and sintering was investigated. The use of highly dispersed Mg(OH)2 powder (HD powder) resulted in a lower calcination temperature. Forsterite powder of high homogeneity and small particle size prepared from the HD powder enabled synthesis of high-density forsterite ceramics by ordinary sintering without applying external pressure. Moreover, transparent forsterite ceramics were successfully synthesized through addition of excess Mg to the precursors to compensate for Mg evaporated during the sintering process. Subsequent dielectric measurements revealed that the transparent forsterite ceramics had a very low dielectric loss (tan δ<10−4 ). 相似文献
107.
Interfacial tension between demixed solutions of polystyrene + methylcyclohexane has been measured near the critical temperature as a function of temperature using polystyrenes with molecular weights 9000 ~ 1.26 × 106. The critical exponent for the interfacial tension was determined to be about 1.30 for the lower molecular weight systems. However, for higher molecular weights the exponent could not be obtained because the system departed from critical behaviour. Magnitudes of the interfacial tension were proportional to about N?0.44, where N is the polymerization index. Experimental results were compared with the recently-proposed theories and found to be in qualitative agreement. The tricritical theory of polymer solutions was also compared with the experimental results. 相似文献
108.
Yasushi Endo Riichiro Usuki Takashi Kaneda 《Journal of the American Oil Chemists' Society》1985,62(9):1387-1390
To understand the mechanism of the antioxidant effect of chlorophyll on the autoxidation of oils in the dark, antioxidant
activities of several derivatives of chlorophyll were compared. Antioxidant activities were observed in chlorophyll derivatives
such as protopor-phyrin methyl ester and its magnesium chelated compound. Porphyrin seems to be an essential chemical structure
for the antioxidant activity of chlorophyll. Chlorophyll did not decompose the hydroperoxides, but reduced free radicals such
as 1,1-diphenyl-2-picrylhydrazyl. Electron spin resonance spectrum of the π-cation radical was recorded during the oxidation
of chlorophyll in methyl linoleate solution. These observations suggest that chlorophyll may act as a hydrogen donor to break
the chain reaction. 相似文献
109.
Yasushi Murakami Taki Matsumoto Kiyochika Yahikozawa Yoshio Takasu 《Catalysis Today》1995,23(4):383-389
The sol-gel process for the hydrolysis and polycondensation of tin tetra-n-butoxide in butanol was followed by viscosity measurements. The precipitation of tin-containing ultrafine particles was observed without any variation in the solution viscosity in the absence of diethylene glycols, while the viscosity increase was made without any precipitation by the addition of diethylene glycol. The induction period and the rate of the viscosity increase after the induction period was independent of the diethylene glycol content but depended upon the water content. The Monte Carlo simulation data were consistent with data for the viscosity experiment. The simulation was based on a kinetic model of the slow hydrolysis of tin tetra-n-butoxide, the reverse reaction of hydrolysis, and the polycondensation of the hydroxy derivatives. 相似文献
110.
Yuen May Choo Ah Ngan Ma Hawari Yahaya Y. Yamauchi M. Bounoshita M. Saito 《Journal of the American Oil Chemists' Society》1996,73(4):523-525
Successful separation of triglycerides, diglycerides, free fatty acids, carotenes, tocopherol, and tocotrienols from crude
palm oil has been achieved by supercritical fluid chromatography (SFC) with a combination of a C18 and a silica gel column.
The separation was carried out by the programmed extraction elution method. Free fatty acids were separated into five components
by gas-liquid chromatography; tocopherol and tocotrienols were also separated into four components by SFC analysis, and the
pure fractionated carotenes were obtained by preparative SFC. Thus, by using supercritical fluid chromatography, crude palm
oil components can be separated and fractionated, based on differences in their functional groups. 相似文献