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991.
The vacuum residual from Iranian Light crude oil are separated into a series of 16 narrow fractions according to the molecular weight by the supercritical fluid extraction and fractional (SFEF) technology. The chemical element and the UV spectrum of each fraction are analyzed. The effects of several factors on the interfacial tension are investigated, which are the fraction concentration in oil phase, the ratio of oil component, the salts dissolved in the water phase and the pH value. The interfacial tension decreases rapidly as the concentration of the residual fraction in the oil increases, showing a higher interfacial activity of the fraction. The interfacial tension changes, as the amount of absorption or the state of the fractions in the interface changes resulting from different ratios of oil, different kinds or concentrations of salts in water, and different pH values. It is concluded that the intrfacial tension changes regularly, corresponding to the regular molecular parameters of the vacuum residual fractions.  相似文献   
992.
Poly(ethylene terephthalate) (PET)/silica nanocomposites were successfully prepared by in situ polymerization. Silica nanoparticles were uniformly dispersed in the process of polymerization. By means of hot‐stage polarization microscope and DSC, the influence of nanosilica on the crystallization of PET/silica nanocomposites has been clarified. The results show that nanosilica does not behave as a nucleating agent in PET but postpones the appearance of crystallite. This phenomenon is very favor to improve spinnability. The investigation on melt spinning of PET/silica nanocomposites also shows that it is advantageous to spinning with descending the spinning temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2564–2568, 2007  相似文献   
993.
A novel glass–ceramic material was developed from the melt of a TiO2-containing iron-making slag with additional waste glass. The high percentage (∼20 wt% TiO2) of this network-modifying oxide has promoted a crystallization of the parent glass, resulting in a fine-grained, homogeneous polycrystalline material with high mechanical properties ( E =120 GPa, flexural strength=∼180 MPa, and Vickers hardness=7 GPa) after a heat treatment at 1100°C for 2 h. The room temperature and elevated temperature fracture toughness were also studied. The main crystalline phases of the glass–ceramic material were of the pyroxene series until heat-treatment temperature reached 1000°C, at which titanium-rich perovskite and armalcolite crystals became the dominant phases. The end material is high-strength, aesthetically acceptable (metallic gray or opaque brown colored), and suitable for structural and architectural applications.  相似文献   
994.
用于测定钢液低氧含量的双层固体电解质研究   总被引:1,自引:0,他引:1  
采用“毛坯浆料法”在ZrO2(9%摩尔含量MgO)管状固体电解质基体表面制备了厚度为1-4μm的ZrO2(10%摩尔含量Y2O3)固体电解质涂层,并分别对此在本实验室和美国LeedsandNorthrup公司进行了钢液低氧含量测试,结果表明:涂层没有破坏基体的抗热震性:氧浓差电池电动势的重现性偏差由原来的±2mV;电动势的绝对值提高10mV左右;而比日本Toray公司的同类产品提高35mV,这说明  相似文献   
995.
文章通过阐述设计管理模式的运用及其目标,分析了设计管理与品牌价值之间的相互关系,从提升产品质量,提升品牌的功能价值和附加价值几方面进行了系统研究。提出在当前卷烟品牌竞争形势下,应当将设计管理模式有效地运用到企业的产品设计和品牌战略之中,充分肯定了设计管理作为创新型管理手段在建立卷烟品牌价值方面具有的重要意义。  相似文献   
996.
电致伸缩是指在外电场作用下电介质所产生的与场强二次方成正比的应变。近年来对聚氨酯电致伸缩性能的研究发现,聚氨酯弹性体综合了压电聚合物与传统的锆钛酸铅(PZT)压电陶瓷片的优点,具有很好的应用前景,本文简单介绍了聚氨酯的电致伸缩效应。  相似文献   
997.
Y2O3改性的MgO—ZrO2共析陶瓷   总被引:2,自引:0,他引:2  
共析MgO-ZrO2陶瓷添加Y2O3可以获得高温热稳定性和较佳的力学性能,添加2%Y2O3时断裂韧性为7.6MPa.m^1/2,弯曲强度为618MPa,用透射电子显微镜详细研究和讨论了上述材料的时效显微组织和韧化的原因。  相似文献   
998.
Organic–inorganic hybrid materials and mem branes were prepared through coating on Teflon plate or dip‐coating on microporous alumina substrates with the solution of glycidylmethacrylate (GMA) and γ‐methacryloxypropyl trimethoxy silane (γ‐MPS) copolymer, followed by ring‐opening of the GMA moiety with trimethylamine hydrochloric and sol–gel reaction of the γ‐MPS moiety. Composition of the GMA and γ‐MPS copolymer was varied by changing the feed ratio of GMA to γ‐MPS during the copolymerization. So the thermal stability, hydrophilicity, electrical properties, etc. of the hybrid materials and membranes were varied. Results showed that as the γ‐MPS amount increased in the copolymer, Td (the temperature on thermogram at 5% weight loss) value of the hybrid materials and water contact angle of the hybrid membrane generally increased, while the anion exchange capacity, water uptake (WR) and pure water flux decreased. The charge transition point of the hybrid membranes deduced from their streaming potential behavior decreased from pH > 12 to pH = 7–8 as the γ‐MPS amount increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3580–3589, 2006  相似文献   
999.
以邻氨基苯甲酸为起始原料,经重氮化、芳基化、取代和脱水等步骤合成药物中间体4′-甲基-2-腈基联苯.通过正交实验得到芳基化反应较佳条件为:10mol/L氢氧化钠15mL,甲苯30mL,反应温度5℃,反应时间5h,产物4′-甲基-2-联苯羧酸的产率为59.4%. 考察了脱水剂种类,脱水反应较佳的实验条件为氯化亚砜15mL,4′-甲基-2-联苯酰胺2.6g,反应8h,产物4′-甲基-2-腈基联苯的产率为67.7%.  相似文献   
1000.
Temperature measurements have been performed in the process of electron‐beam curing of EB‐I and EB‐II epoxy resin systems. The influence of initiator content, resin type, and dose rate on the temperature of the systems was studied. Transverse and longitudinal temperatures of samples in the glass vessel were also analyzed. The nature of temperature curves varied with the different epoxy resin systems in the steel mold, but did not change with different contents of the initiator. At the same time, the heat had no effect on the gel fraction of epoxy resin systems. The temperature curve was greatly affected by the dose rate, and its peak value, peak width, and plateau value also increased with it. The transverse temperature of EB‐II glass vessel samples increased as the radiation dose increased and, in the same sample, the temperature reduced as the distance between the radiation center and the test point increased. The longitudinal temperature of EB‐I and EB‐II resin systems in a glass vessel decreased as the radiation depth increased. As the radiation dose increased, the temperature of the EB‐I resin system increased simultaneously, while that of the EB‐II resin system initially increased and then kept constant when the dose reached a certain value. The temperatures of these two resin systems decreased rapidly when the radiation process stopped. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2217–2222, 2004  相似文献   
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