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101.
W. Dennis Pocklington 《Journal of the American Oil Chemists' Society》1992,69(8):789-793
The development, by collaborative study, of a standardized method for the determination of tetrachloroethylene in olive oils
is described. The results of the study, which was carried out in 1989 under the direction of the International Olive Oil Council
(IOOC), are presented and show that tetrachloroethylene can be readily determined, to an acceptable degree of precision, by
gas-liquid chromatography with electron capture detection. A limited number of results obtained for the determination of trichloroethylene
and chloroform by the same method indicate that a similar precision could be obtained with the method when determining these
solvents also. 相似文献
102.
采用种子乳液聚合法合成了聚氨酯一聚丙烯酸乙(丁)酯[PU/PE(B)A]复合乳液。并研究了不同组成对复合乳液性质、相客性、阻尼性能及拉伸性能的影响。耐水性及稳定性测试表明,随PE(B)A含量的增加,涂膜的耐水性变好,而乳液的稳定性变差。动态力学性能测试(DMS)表明,合成的PU/PE(B)A复合乳液为半相容体系,其相容性随PE(B)A含量的增加而增强。DMS和拉伸试验表明PU/PEA/P(B)A(质量比50/25/25)复合乳液具有优良的阻尼性能、抗拉强度和断裂伸长率,可用作宽温域阻尼涂料。 相似文献
103.
Riccardo Carli Raymond Le Van Mao Claudia L. Blanchi Vittorio Ragaini 《Catalysis Letters》1993,21(3-4):265-274
Gallium species which were incorporated initially in the oxide form, were all in the (+3) oxidation state in the hybrid catalyst and exhibited two types of hydrogen chemisorption sites, shw and shs. The stronger sorption sites shs which predominated at higher gallium dispersion, corresponded probably to the most effective surface configuration for gallium in the aromatization ofn-butane. 相似文献
104.
Two kinds of novel chelating adsorbents have been synthesized to separate boron from aqueous solutions. One is the boron-specific chelating resin, synthesized by the functionalization of macroporous poly (glycidyl methacrylate-co- trimethylolpropane trimethacrylate), with N-methylglucamine. The other is the organic-inorganic hybrid mesoporous SBA-15 with polyol functional groups, prepared by a two-step post-grafting method. The resin can adsorb boron in almost all pH range, and its maximum uptake capacity reaches 1.15 mmol/g. The present study of the polyol-functionalized SBA-15 shows that the post-grafting is successful and the resulting adsorbent has the uptake capacity of 0.63 mmol/g. 相似文献
105.
将壳聚糖/钙盐复合膜浸泡在磷酸二氢钾溶液中制备了壳聚糖/磷钙杂化膜.用电子扫描电镜观察杂化膜和膜内磷钙微粒的形貌,研究了杂化膜的力学性能、溶胀率、吸光度及热稳定性.结果表明,杂化膜内磷钙晶体为柱状和层状结构,磷钙被包裹在杂化膜内,并与壳聚糖膜形成紧密的连续结构.随着膜中磷钙的质量分数从2.1%增加到8.0%,膜的溶胀率从102%增加到144%,其在200~800 nm波长范围的吸光度也逐渐增加.当磷钙的质量分数为7.0%时,杂化膜的力学性能最佳,其拉伸强度为54.42 MPa、弹性模量为4045.72 MPa、断裂伸长率为4.85%.杂化膜的热分解温度为299℃,高于壳聚糖膜的分解温度290℃.这种具有层状磷钙结构的杂化膜具有良好的生物相容性,可作为一种潜在的支架材料. 相似文献
106.
107.
聚酰亚胺/二氧化硅杂化膜的制备与介电性能的研究 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了BTDA-ODA聚酰亚胺/SiO2杂化膜,利用红外分光光度计(FTIR)、热重分析仪(TGA)和透射电镜(TEM)研究了杂化膜的微观结构和热性能,并对杂化膜的介电常数(e)和介电损耗(tand)随SiO2粒子含量和电场频率的变化进行了分析和讨论。结果表明:杂化膜的介电常数和介电损耗随SiO2粒子含量的增加而增大,随电场频率的升高而逐渐降低,用考虑到粒子的形状因素和两相间相互作用的EMT模型可以预测聚酰亚胺/SiO2杂化膜的介电常数。 相似文献
108.
109.
Rana M. Tubaileh Antonio Garrido-Fernández M. Victoria Ruiz-Méndez Manuel León-Camacho Enrique Graciani-Constante 《Journal of the American Oil Chemists' Society》2002,79(1):101-104
Changes in the contents of waxes and fatty alcohols during deodorization/physical refining of bleached olive oil were studied.
Experiments were carried out with 1.85% acidity oil, which was physically refined in a discontinuous deodorizer of 250-kg
maximum capacity using nitrogen as stripping gas instead of steam. The variables studied were load and temperature of oil
in the deodorizer as well as N2 flow. Analyses of waxes and alcohols were carried out at different operation times. The maximum content of wax was always
observed when the oil reached the deodorization temperature. The variation in the wax content depended on temperature and
N2 flow. Wax decomposition started and continued during the operating time, and a progressive decrease, which was pronounced
between 3 and 4 h, was observed. Small changes in waxes were observed between 4 and 5 h. Total content of fatty alcohols diminished
throughout the operating time, and changes did not depend on the variables studied. 相似文献
110.
L. Di Giovacchino M. Solinas M. Miccoli 《Journal of the American Oil Chemists' Society》1994,71(11):1189-1194
Research has been carried out to ascertai the effects of different processing systems on olive oil quality. Tests were performed
in industrial oil mills that were equipped with both pressure and centrifugation systems. Results show that oils extracted
from good-quality olives do not differ in free fatty acids, peroxide value, ultraviolet absorption and organoleptic properties.
Polyphenols ando-diphenols contents and induction times are higher in oils obtained from good-quality olives by the pressure system because
it does not require addition of water to the olive paste. The centrifugation system requires the addition of warm water to
the olive paste and helps to obtain oils with a lower content of natural antioxidants. Oils obtained from poorquality or from
ripe olives in continuous centrifugal plants are lower in free fatty acids than those obtained by the pressure system.
Dr. Mario Solinas is deceased—May 23, 1993. 相似文献