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亲水基团PEG分子量对漆酚基乳化剂性能的影响 总被引:1,自引:1,他引:0
以漆酚(U)、环氧氯丙烷(ECH)、聚乙二醇(PEG)为原料制备一系列漆酚基乳化剂(UE).用IR、^1H-NMR对UE的结构进行表征,用吊片法测定UE水溶液的表面张力,并研究了UE的溶解性、乳化性、起泡高度等性能.结果表明:UE仍然保留了漆酚分子的不饱和长侧链;所制得的UE均溶于水且都能较好地降低水溶液的表面张力,随着亲水基团PEG分子量的增大,UE降低表面张力的能力降低;PEG分子量对UE的起泡能力影响不大,但对UE乳化自油的能力影响较大,当PEG的分子量为1.0×10^3时,所制得的UE10的乳化能力最强. 相似文献
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《文物保护研究》2012,57(1):28-36
ABSTRACTA pre-restoration diagnosis revealed a high amount of pyrite in the wood of the Lyon Saint-Georges 4 shipwreck (end of the second century). The occurrence of this phase is supposed to result from the microbiologically influenced corrosion of the iron fasteners. So, all the nails and metallic elements were removed from the remains before treatment and the wreck was consolidated by polyethylene glycol impregnation coupled to a specific desalination process. Treated and non-treated samples extracted from the wreck were studied in order to identify the iron/sulfur-containing compounds present in the wood before and after treatment and figure out its effect. Sample analyses relied on an original approach combining magnetic characterization methods and more common elemental and structural analysis methods. The results showed that the treatment was effective in removing soluble salts. However, a large amount of unstable iron sulfides remained inside the wood. 相似文献
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Tornado码二部图构造是一个非常重要的问题。基于PEG算法构造LDPC码二部图时显现的各种优点,本文提出了一种改进的PEG构图算法。仿真结果表明,改进的算法比原PEG算法有更快的执行速度,并且基于此算法构造的Tornado码也比原始的Tornado码有更好的性能。 相似文献
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彭勇宜 《湖南城市学院学报》2002,19(3):45-47
人工诱导鱼类细胞融合是细胞工程中的一项重要技术 .鱼类细胞是一种比较理想的融合材料 .概述了鱼类细胞融合研究的发展和主要成果 ,鱼类细胞融合技术主要包括病毒法、PEG法、电融合法、激光微束法 .同时指出了鱼类细胞融合中的值得继续探讨的问题 相似文献
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花生种子经人工老化处理后活力明显下降,用25%PEG处理可提高种子活力,从扫描电镜观察看到,高活力种子胚根表皮细胞完整,老化处理后,表皮细胞呈疏松突起,严重的成块状脱落,皮层裸露,出现畸形很尖,能谱分析表明,高活力种子胚根尖细胞内含有多种元素,其含量的百分比顺序为:K>Ca>Si>P>S>Al>Cl。根尖含Ca最多,越往上部逐渐减少;K的含量却相反,根尖最低,越往上部越高,人工处理的种子Ca含量明显下降,老化10天以上的种子,胚根尖细胞的Ca完全消失,K的含量也随老化时间的增加而减少,PEG渗调处理能明显增加Ca的含量,减少细胞劣变的损伤,防止表皮细胞的脱落,因而提高种子活力。 相似文献
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双水相萃取法分离生活污水中重金属离子和机理研究 总被引:1,自引:0,他引:1
研究了生活污水中铅(Ⅱ)、铁(Ⅲ)、铬(Ⅲ)、锰(Ⅱ)等金属离子在聚乙二醇(PEG) -Na2SO4-邻苯二酚紫(PV)体系中的萃取行为.探讨了萃取酸度、萃取剂用量、硫酸铵浓度对金属离子萃取率的影响.实验结果表明,通过控制一定的条件,可以实现铬(Ⅲ)、铅(Ⅱ)与部分混合金属离子之间的萃取分离. 相似文献
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You-hong Fang Chun-xiao Chen Bing-ling Zhang 《Journal of Zhejiang University. Science. B》2009,10(1):46-51
Background: Capsule endoscopy is a novel non-invasive method for visualization of the entire small bowel. The diagnostic yield of capsule endoscopy depends on the quality of visualization of the small bowel mucosa and its complete passage through the small bowel. To date, there is no standardized protocol for bowel preparation before capsule endoscopy. The addition ofsimethicone in the bowel preparation for the purpose of reducing air bubbles in the intestinal lumen had only been studied by a few investigators. Methods: Sixty-four participants were randomly divided into two groups to receive a bowel preparation of polyethylene glycol (PEG) solution (Group 1) and both PEG solution and simethicone (Group 2). The PEG solution and sime-thicone were taken the night before and 20 min prior to capsule endoscopy, respectively. Frames taken in the small intestine were examined and scored for luminal bubbles by two professional capsule endoscopists. Gastric emptying time and small bowel transit time were also recorded. Results: Simethicone significantly reduced luminal bubbles both in the proximal and distal small intes-tines. The mean time proportions with slight bubbles in the proximal and distal intestines in Group 2 were 97.1% and 99.0%, respectively, compared with 67.2% (P<0.001) and 68.8% (P<0.001) in Group 1. Simethicone had no effect on mean gastric emptying time, 32.08 min in Group 2 compared with 30.88 min in Group 1 (P=0.868), but it did increase mean small intestinal transit time from 227.28 to 281.84 min (P=0.003). Conclusion: Bowel preparation with both PEG and simethicone significantly reduced bubbles in the intestinal lumen and improved the visualization of the small bowel by capsule endoscopy without any side effects observed. 相似文献
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本文研究了PEG-2000水溶液在硫酸铵存在下,分成液-液两相的条件和偶氮氯膦-PN及Pd(Ⅱ)配合物在该体系两相间的分配行为,实现了Pd(Ⅱ)的定量萃取分离.在此基础上建立了Pd(Ⅱ)-CPA-PN-PEG-2000非有机溶剂液-液萃取分光光度法测定微量钯的新方法. 相似文献