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101.
To reveal the effect of the nigrosine dye, that the addition of the dye lowers the crystallization point (Tc) of molten polyamide resins with substantially no shift in the melting point (Tm), thus suppressing the crystallization enhancement of the crystalline nucleation agents, the characteristics of polyamide 66 (PA‐66) containing nigrosine dye EX (N‐EX) were investigated. Differential scanning calorimetry (DSC) analysis showed that the addition of N‐EX reduced the crystallization rate and Tc of molten PA‐66 with substantially no shift in Tm, and the crystallization enthalpy per unit of weight of PA‐66 was substantially constant. Tc of molten PA‐66 was lowered with an increase in the amount of N‐EX and reached its maximum at 13 wt % N‐EX. Dynamic mechanical analysis showed that the glass‐transition temperature and the secondary glass‐transition temperature increased with an increasing amount of the dye. On the other hand, the DSC and X‐ray diffraction results indicated that no dye molecule was present in the crystal structure of PA‐66. This effect of the nigrosine dye on PA‐66 is in contrast to those of crystalline nucleation agents, plasticizers, and antiplasticizers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3270–3274, 2006 相似文献
102.
Zhaoxia Song Hiroyasu Nishiguchi Wei Liu Hiroshi Yamada Akihide Takami Kumiko Kudo Katsutoshi Nagaoka Yusaku Takita 《Catalysis Letters》2006,111(3-4):169-171
Redox properties of CeO2 and Pt-Rh/CeO2 were studied by temporal analysis of products (TAP) method using alternative pulses of CO and O2. A portion of pulsed CO was oxidized to CO2 and a portion of CO was adsorbed on the surface. Pulsing 18O2 onto the catalyst which has surface species derived from CO, evolved CO2 contained no 18O suggesting that the surface species will be carbonate ions. 相似文献
103.
This paper presents a new maritime lifesaving multiple-effect solar still design where several extended wicks feed seawater to their evaporating areas by capillary force, and the resulting water vapor diffuses and condenses on facing wicks with the condensate flowing through the wicks into storage bags. A theoretical analysis showed that a temperature drop through diffusion layers between evaporating and condensing wicks slowly increases in the main evaporating areas and rapidly near salt depositions whereas the evaporation rate decreases slowly in the main area and rapidly near salt depositions. These changes are caused by increases in salt concentrations and resulting boiling point elevation. With steady-state transfer analysis, the proposed still is predicted to produce about 15 kg m −2d−1 fresh water on a sunny day of 22 MJm−2d−1 solar radiation, showing a potential to be a maritime lifesaving desalinator. 相似文献
104.
This paper presents a simplified method for the chemical synthesis of cholest-4-en-3-one, which is a naturally occurring steroid
and a salient intermediate in steroid chemistry. Pyridinium chlorochromate (PCC) in refluxing benzene has been found to be
an effective and convenient reagent for the oxidation and concomitant isomerization of cholest-5-en-3β-ol (cholesterol) to
cholest-4-en-3-one in high yield. Also described are the carbon-13 nuclear magnetic resonance spectral properties of cholest-4-en-3-one
and of the isolated reaction intermediate cholest-5-en-3-one.
Based on a paper presented at the Symposium on Plant and Fungal Sterols: Biosynthesis Metabolism and function held at the
AOCS Annual Meeting, Baltimore, MD, April 1990. 相似文献
105.
Tsuyoshi Hagio Kazuo Kobayashi Hisayoshi Yoshida Hiroaki Yasunaga Hiroshi Nishikawa 《Journal of the American Ceramic Society》1989,72(8):1482-1484
Pressureless sintering of hexagonal boron nitride (BN) was performed using a powder activated by mechano-chemical treatments. Physical properties of the sintered BN bodies depend on the type of starting powder and the conditions of the treatments. The BN body, which was obtained at 2000°C using an appropriate activated powder, was 99 wt% pure and was excellent in mechanical and physical properties, in spite of its low density (1.64 g/cm3 ). 相似文献
106.
Yoshihiro Hirata Kazuyoshi Sakeda Yumi Matsushita Kinji Shimada Yoshimi Ishihara 《Journal of the American Ceramic Society》1989,72(6):995-1002
Submicrometer SiO2 -Al2 O3 powders with compositions of 46.5 to 76.6 wt% Al2 O3 were prepared by hydrolysis of mixed alkoxides. Phase change, mullite composition, and particle size of powders with heating were analyzed by DTA, XRD, IR, BET, and TEM. As-produced amorphous powders partially transformed to mullite and Al-Si spinel at around 980°C. The compositions of mullite produced at 1400° and 1550°C were richer in Al2 O3 than the compositions of stable mullite solid solutions predicted from the phase diagram of the SiO2 -Al2 O3 system. Particle size decreased with increasing Al2 O3 content. The sintered densities depended upon the amount of SiO2 -rich glassy phase formed during sintering and the green density expressed as a function of particle size. 相似文献
107.
Yasuro Ikuma Eriko Shimada Nobuko Okamura 《Journal of the American Ceramic Society》2005,88(2):419-423
An extensive X-ray study of CeO2 –Nd2 O3 solid solutions was performed, and the densities of solid solutions containing various concentrations of NdO1.5 were measured using several techniques. Solid solutions containing 0–80 mol% NdO1.5 were synthesized by coprecipitation from Ce(NO3 )3 and Nd(NO3 )3 aqueous solutions, and the coprecipitated samples were sintered at 1400°C. A fluorite structure was observed for CeO2 –NdO1.5 solid solutions with 0–40 mol% NdO1.5 , which changed to a rare earth C-type structure at 45–75 mol% NdO1.5 . The change in the lattice parameters of CeO2 –NdO1.5 solid solutions, when plotted with respect to the NdO1.5 concentration, showed that the lattice parameters followed Vegard's law in both the fluorite and rare earth C-type regions. The maximum solubility limit for NdO1.5 in CeO2 solid solution was approximately 75 mol%. The relationship between the density and the Nd concentration indicated that the defect structure followed the anion vacancy model over the entire range (0–70 mol% NdO1.5 ) of solid solution. 相似文献
108.
Toshihiro Nagao Yuji Shimada Yoshie Yamauchi-Sato Takaya Yamamoto Masaaki Kasai Kentaro Tsutsumi Akio Sugihara Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2002,79(3):303-308
A commercial product of CLA contains almost equal amounts of cis-9,trans-11 (c9,t11)-CLA and trans-10,cis-12 (t10,c12)-CLA. We attempted to enrich the two isomers by a two-step selective esterification using Candida rugosa lipase that acted on c9,t11-CLA more strongly than on t10,c12-CLA. An FFA mixture containing CLA isomers was esterified with an equimolar amount of lauryl alcohol in a mixture of 20%
water and the lipase. When the esterification of total FA reached 50%, two isomers were fractionated in a good yield: t10,c12-CLA was enriched in FFA, and c9,t11-CLA was recovered in lauryl esters. The FFA were esterified again to enrich t10,c12-CLA. At 27.3% esterification of total FA, the t10,c12-CLA content in FFA increased to 64.8 wt% with 89.3% recovery: The ratio of the content of t10,c12-CLA to that of two isomers was 95.9%. Lauryl esters obtained by the single esterification were employed for enrichment
of c9,t11-CLA. After the esters were hydrolyzed, the resulting FFA were esterified again with lauryl alcohol. At 62.0% esterification
of total FA, the c9,t11-CLA content in lauryl esters increased to 73.3 wt% with 79.4% recovery: The ratio of the content of c9,t11-CLA to that of two isomers was 95.6%. In a 600-g-scale purification, molecular distillation was effective in separating
the reaction mixture into lauryl alcohol, FFA, and lauryl ester fractions. 相似文献
109.
Keiji Mimura Susumu Yukawa Yoshio Mori Kazuya Okada Masatoshi Mune Osamu Nishikawa Akira Hibino Miyahiko Sonobe Tetuya Goto Hiroshi Nomoto 《Lipids》1991,26(12):1102-1107
We investigated the effect of platelet-activating factor (PAF) and of the PAF specific antagonist CV-6209 on plasma lipid
metabolism, and particularly on post-heparin plasma lipolytic activity in male Wistar rats. Lipoprotein lipase (LPL) activity
was enhanced by intravenous injection of PAF before intravenous injection of heparin when the PAF dose was low (0.2 μg/kg).
PAF activated hepatic triacylglycerol lipase (HTGL) activity dose-dependently. Plasma triacylglycerols (TG) significantly
decreased with the activation of LPL and/or HTGL. Plasma total cholesterol (TC) and phospholipid (PL) levels decreased at
a low dose of PAF (0.2 μg/kg), but increased when higher doses were used. The PAF antagonist CV-6209 partially reversed the
PAF induced effects on HTGL, TC and PL.
Based on a paper presented at the Third International Conference on Platelet-Activating Factor and Structurally Related Alkyl
Ether Lipids, Tokyo, Japan, May 1989. 相似文献
110.
Isao Mochida Kenjiro Iwamoto Tsutomu Tahara Yozo Korai Hiroshi Fujitsu Kenjiro Takeshita 《Fuel》1982,61(7):603-609
Reactivities of several coals of different ranks have been examined in degrading extractions with aromatic solvents under apparently non-hydrogenative reaction conditions. Pyrene and A240 pitch liquefied the fusible coals in high yields and the slightly-fusible coals in moderate yields, indicating the importance of fusibility in such liquefaction processes. A240-LS pitch is a powerful solvent for slightly-fusible coals. Considerable amounts of pyridine- or THF-soluble fractions were produced especially with A240-LS pitch. A240 pitch is a better solvent than pyrene for some slightly-fusible coals. However, the extent of depolymerization of liquefied coal, pyridine- or THF-solubility, was definitely inferior. Yields of such fractions are higher for lower-rank coals. The mechanism of coal liquefaction under apparently non-hydrogenative conditions is discussed with emphasis on the stabilization of thermal fragments derived from the coal. 相似文献