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91.
Takaaki Tsurumi Young-Bae Kil Kouhei Nagatoh Hirofumi Kakemoto Satoshi Wada Sadayuki Takahashi 《Journal of the American Ceramic Society》2002,85(8):1993-1996
The material coefficients of "soft" and "hard" lead zirconate titanate (PZT) ceramics were determined as complex values by the nonlinear least-squares-fitting of immittance data measured for length-extensional bar resonators. The piezoelectric d -constant should be a complex value to obtain a best fitting between observed and calculated results. Because the elastic, dielectric, and piezoelectric losses determined in this process were not "intrinsic" losses, a calculation process to evaluate the "intrinsic" losses was proposed. It was confirmed that the intrinsic losses were smaller than the corresponding extrinsic losses. The intrinsic piezoelectric loss existed in both soft and hard PZTs; ∼50% of the loss of piezoelectric d -constant was derived from the elastic and dielectric losses. The most notable difference between the soft and hard PZTs was observed in their elastic losses. 相似文献
92.
The matrix concept was used to characterize the chromatographic rules in the elution of molecular species of triglyceride.
To prove the hypothesis experimentally, cacao butter, palm oil, linseed oil, olive oil, rapeseed oil and triglyceride of “Ogonori”
(Gracilaria verrucosa) were examined. A matrix model was suggested to help determine the individual molecular species of naturally occurring triglycerides. 相似文献
93.
Studies are reported of the effect of an essential fatty acid (EFA) deficiency on synthesis of triglycerides (TG) and phospholipids
(PL) and secretion of these compounds by livers of male Sprague-Dawley rats. Animals were fed a semipurified diet containing
corn oil or hydrogenated coconut oil (HCO) as the sole source of fat or no fat from weaning to 20 weeks of age. Liver function
of the animals in each group was compared by an isolated liver perfusion technique with perfusates containing erythrocytes
and linoleate, and in vivo experiments via tail vein injection of palmitate-3H. Perfusion experiments showed that an EFA deficiency reduced the ability of the liver to secrete TG and PL. Accumulation
of TG in the liver and its diminished secretion into the blood of EFA deficient animals were demonstrated by in vivo experiments
with palmitate-3H. The rate of conversion of linoleate to arachidonate and synthesis of PL was greater in livers of EFA deficient rats than
in the control, corn oil fed animals. The results suggest a relationship of EFA metabolism to lipid transport.
One of five papers to be published from the Symposium “Lipid Transport” presented at the AOCS Meeting, New Orleans, April
1970. 相似文献
94.
J. Kurashige N. Matsuzaki H. Takahashi 《Journal of the American Oil Chemists' Society》1993,70(9):849-852
The bioreactor system to interesterify edible oils and fats at an ultra-micro aqueous phase of 100 ppm and less was investigated.
The adsorption of lecithin, together with lipase onto a carrier, was effective for conducting the interesterifying reaction
efficiently for oils and fats in micro aqueous phase.
To improve the handling properties of palm oil at rather low temperature, palm oil was blended with canola or soybean oil,
and then these blended oils were modified by enzymatic selective interesterification in a solvent-free, ultra-micro aqueous
bioreactor system with an immobilized lipase that had 1,3-positional specificity. The effects of enzymatic interesterification
were confirmed by triglyceride determination, by solid fat content profiles and by cloud point profiles, which were also compared
to products of chemical interesterification. The improvement in the fluidity of blended oils with canola oil by the enzymatic
reaction was bigger than with soybean oil, and chemical interesterification had no effects on the fluidity of blended oils. 相似文献
95.
Masaru Takahashi Noriyuki Inoue Tatsuya Takeguchi Shinji Iwamoto Masashi Inoue Tsunenori Watanabe 《Journal of the American Ceramic Society》2006,89(7):2158-2166
The reaction of mixtures of aluminum isopropoxide and gallium acetylacetonate in 1,4-butanediol or 1,5-pentanediol at high temperatures (glycothermal reaction) directly gave the γ-Ga2 O3 –Al2 O3 solid solutions, which had high catalytic activities for selective reduction of NO using methane as the reducing agent. However, the reaction with a higher Al/(Ga+Al) charged ratio yielded the glycol derivative of boehmite as a by-product and the catalytic activity of the solid solution decreased. Therefore, synthesis of the solid solution using various glycols was examined and it was found that solid solutions with high Al contents without contamination of the glycol derivative of boehmite were obtained by using 1,6-hexanediol as a reaction medium. The solid solution exhibited a higher NO conversion than that synthesized in other glycols. 相似文献
96.
In order to examine the conduction behaviour in the sintered oxides of MoO3-doped Bi2O3, the electrical conductivity in air and the EMF of oxygen gas concentration cell were measured with respect to the phase relation determined by X-ray diffraction.The tetragonal single phase oxide containing 22 mol% MoO3 was found to be a high oxide ion conductor, the conductivity of which was comparable to those of stabilized zirconias. The partial electronic conduction in this phase was negligibly small at relatively high oxygen pressure. The oxide ion conduction was considered to be attributable to an appreciable amount of oxygen vacancies present in the crystal. In the monoclinic compound 3Bi2O3·2MoO3, the oxide ion conduction was also observed. Although the conductivity of this phase was somewhat lower than that of the tetragonal phase, the activation energy for conduction (53·5 kJ mol–1) was much lower than the values for usual oxide ion conductors. 相似文献
97.
Viscoelastic properties of poly(isoprene-b-styrene) in dioctylphthalate under steady shear flow were measured near the order—disorder transition temperature. In ordered states, first normal stress difference N1 is proportional to shear rate
at low
region, but becomes proportional to
at the high
region, similar to the N1 behaviour of polymer blends undergoing shear-induced homogenization. Because the existence of microdomains was confirmed at the high
region by the flow birefringence method, it is concluded that the above N1 behaviour is not caused by shear-induced homogenization, but is probably caused by the shear-induced alignment of the microdomain structure. 相似文献
98.
The influence of age and cholesterol on polyunsaturated fatty acids (PUFa) levels was studied in young and old male Sprague-Dawley
rats. Animals were fed a fat-free diet supplemented with 10% (by wt) safflower oil with or without 1% cholesterol for 8 wk.
As a result of cholesterol feeding, proportions of linoleic acid (18∶2n−6) and dihomo-γ-linolenic acid (30∶3n−6) were increased
and and that of arachidonic acid (20∶4n−6) was decreased in the liver and platelet phospholipids in 64-wk-old rats, suggesting
inhibitory effects of cholesterol on 20∶4n−6 synthesis from 18∶2n−6. The prominent age-dependent effect on the levels of PUFA
was a retention of C−22 n−3 PUFA, accompanied by decreased C−22 n−6 PUFA and increased 20∶3n−6 in the liver and platelet phospholipids.
Ratio of 20∶3n−6/20∶4n−6 increased in 64-wk-old rats regardless of dietary cholesterol, suggesting depressed Δ5-desaturase
with age. In aorta phospholipids, 20∶3n−6 content and 20∶3n−6/20∶4n−6 ratio increased with cholesterol supplementation, but
not with age. These results suggest that changes of PUFA composition of platelet phospholipids with age are closely linked
with changes in liver phospholipids. The 20∶4n−6 content in both platelet and aorta phospholipids is kept constant, despite
other n−6 and n−3 PUFA being affected by age. 相似文献
99.
The selective detection of acetylene in gases extracted from isolation oils has been studied to develop an electrochemical
sensor for the diagnostic monitoring of the condition of in-service electrical instruments. Effects of coexisting gases (CH4, C2H6, C2H4, H2 and CO) on the oxidation current of C2H2 were tested using gas-permeable gold-coated and platinum-black electrodes as the sensor. The gold-coated electrode showed
good behaviour for the selective current detection of acetylene under potentiostatic conditions (−0.1 V/Pt-black reference
electrode) in 10m H2SO4 electrolyte solution. 相似文献
100.
Hiroki Takeshita Yuan-Ji Gao Tomoyuki Natsui Erick Rodriguez Masamitsu Miya Katsuhiko Takenaka Tomoo Shiomi 《Polymer》2007,48(26):7660-7671
The microphase separation structure in the molten state and the structure formation in crystallization from such ordered melt were investigated for the blends of polystyrene–polyethylene block copolymers (SE) with polystyrene homopolymer (PS) and polyethylene homopolymer (PE) and for the blends consisting of two kinds of SE with different copolymer compositions from each other, using synchrotron small-angle X-ray scattering techniques (SAXS). The copolymer compositions of SE block copolymers employed were 0.34, 0.58 and 0.73 wt. fraction of PE, and their melt morphologies were cylindrical, lamellar and lamellar, respectively. Macrophase separation or the morphology change in the melt occurred depending on the molecular weight and the blend composition, as reported so far. In crystallization from such macrophase-separated and microphase-separated melts, the melt morphology was completely kept for all the blends. Crystallization behavior was also investigated for the blends. The crystallization within the spherical and cylindrical domains surrounded by glassy PS was not observed for SE/PS blends. In the crystallization from the macrophase-separated melt, two exothermal peaks were observed in the DSC measurements, while a single peak was observed for other blends. For the blends with PS, the degree of crystallinity was depressed and the apparent activation energy of crystallization was high, compared to those for the corresponding neat SE. For SE/PE and SE/SE blends, those were changed depending on the blend composition. 相似文献