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991.
以六甲基二硅氮烷为主要表面处理剂,考察了表面处理剂、处理助剂、水的用量等对白炭黑增强效果的影响。结果表明,处理100份白炭黑时,用25份六甲基二硅氮烷,5份二甲基二乙氧基硅烷,5份水,所得白炭黑对加成型液体硅橡胶增强效果较好。  相似文献   
992.
Na_2O-ZnO-CaO-Al_2O_3-SiO_2烧结微晶玻璃的试制刘世权,许淑惠,袁怡松,杨晓晶(西北轻工业学院712081)SinteredNa_2O-ZnO-CaO-Al_2O_3-SiO_2GlassCeramics¥LiuShiquan...  相似文献   
993.
天然肉桂油臭氧化制取苯甲醛   总被引:10,自引:4,他引:10  
利用天然肉桂油中富含的肉桂醛,经过臭氧化反应和还原反应制得了苯甲醛。由该法制得的苯甲醛在国际上可作为天然苯甲醛使用。  相似文献   
994.
用聚丙烯酸酯乳液提高轮胎帘线储存稳定性   总被引:2,自引:0,他引:2  
研究了一种自交联型五元共聚聚丙烯酸酯乳液的单体种类和配比、加料顺序、表面活性剂的种类和用量、引发剂用量等合成工艺因素与乳液稳定性及其增粘和防紫外线、臭氧老化的关系。用这种乳液改性的RFL浸渍液处理锦纶66轮胎帘线,可以显著改善帘线的储存稳定性。  相似文献   
995.
An organic aqueous solution of metal acetylacetonate precursors was subjected to spray pyrolysis in order to fabricate SrAl2O4:Eu (SAO) nanoparticles. Non-agglomerated luminescent SAO nanoparticles, having a spherical shape with a size of 10–30 nm, were achieved in a single step, while only submicrometer-sized SAO particles were obtained from the conventional ultrasonic pyrolysis of the metal nitrates. Without any post-annealing process, the as-prepared SAO nanoparticles were observed to exhibit a strong photoluminescence, which is comparable with that of the submicrometer-sized SAO particles. A mechanism for the formation of the nanoparticles is also discussed.  相似文献   
996.
Effects of microstructural heterogeneity on material-removal mechanisms and damage-formation processes in the abrasive machining of silicon carbide are investigated. It is shown that the process of material removal in a conventional silicon carbide material with equiaxed-grain micro-structure and strong grain boundaries consists of the formation and propagation of transgranular cracks which results in macroscopic chipping. However, in a silicon carbide material, containing 20 vol% yttrium aluminum garnet (YAG) second phase, with elongated-grain micro-structure and weak grain boundaries, intergranular micro-cracks are formed at the interphase boundaries, leading to dislodgment of individual grains. These different mechanisms of material-removal affect the nature of machining-induced damage. While in the conventional silicon carbide material the machining damage consists of transgranular median/radial cracks, in the heterogeneous silicon carbide material, abrasive machining produces interfacial micro-cracks distributed within a thin surface layer. These two distinct types of machining damage result in a different strength response in the two forms of silicon carbide materials. In the case of the conventional silicon carbide, grinding damage results in a dramatic decrease in strength relative to the as-polished specimens. In contrast, the ground heterogeneous silicon carbide specimens show no strength loss at all.  相似文献   
997.
徐靖  张伟业 《中国水泥》2005,(12):58-61
前言 从我国水泥生产技术的发展来看,由于第二代以及不带热端固定床的第三代推动篦式冷却机均存在高温端部容易漏料、篦饭寿命短、篦板结构形式的缺陷使得其冷却效率差、易出现“红河”、二三次风温低、冷却风量偏大、动力消耗大、热回收效率低等一系列不尽人意之处。我院存对同外有关技术的消化吸收和实验研究的基础上,通过不断开发、优化,  相似文献   
998.
张伟光  王慧萍 《云南化工》2007,34(2):15-16,31
植物油的酶法脱胶是一种新的大豆油脱胶方法。利用新型微生物磷脂酶Lecitase Ultra进行大豆油脱胶的研究,探讨了若干操作参数对大豆油脱胶效果的影响,确定了该酶较优的反应条件:反应时间200 min,加酶量25 mg/kg,pH值4.8,温度46~48℃,大豆油含磷量能降到4.7 mg/kg。结果表明,Lecitase Ultra应用于植物油脱胶效果好且稳定,是一种更适宜于工业化应用的酶种。  相似文献   
999.
A spherical TiCl4/MgCl2‐based catalyst was used in the synthesis of in‐reactor polyethylene/polypropylene alloys by polyethylene homopolymerization and subsequent homopolymerization of propylene in the gas phase. Different conditions in the ethylene homopolymerization stage, such as monomer pressure and polymerization temperature, were investigated, and their influences on the structure and properties of in‐reactor alloys were studied. Raising the polymerization temperature is the most effective way of speeding up polymerization and regulating the ethylene content of polyethylene (PE)/polypropylene (PP) alloys, but it will cause a greater increase in the PE‐b‐PP block copolymer fraction (named fraction D) than in the fraction of PP‐block‐PE in which the PP segments have low or medium isotacticity (named fraction A). Although changing ethylene monomer pressure could influence the ethylene content of PE/PP alloys slightly, it is an effective way of regulating the structural distribution. Reducing the monomer pressure will evidently increase fractions A and D. The mechanical properties of the alloys, including impact strength and flexural modulus, can be regulated in a broad range with changes in polymerization conditions. These properties are highly dependent on the amount, distribution, and chain structure of fractions A and D. The impact strength is affected by both fraction A and fraction D in a complicated way, whereas the flexural modulus is mainly determined by the amount of fraction A. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2136–2143, 2006  相似文献   
1000.
A series of well‐defined and property‐controlled polystyrene (PS)‐b‐poly(ethylene oxide) (PEO)‐b‐polystyrene (PS) triblock copolymers were synthesized by atom‐transfer radical polymerization, using 2‐bromo‐propionate‐end‐group PEO 2000 as macroinitiatators. The structure of triblock copolymers was confirmed by 1H‐NMR and GPC. The relationship between some properties and molecular weight of copolymers was studied. It was found that glass‐transition temperature (Tg) of copolymers gradually rose and crystallinity of copolymers regularly dropped when molecular weight of copolymers increased. The copolymers showed to be amphiphilic. Stable emulsions could form in water layer of copolymer–toluene–water system and the emulsifying abilities of copolymers slightly decreased when molecular weight of copolymers increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 727–730, 2006  相似文献   
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