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991.
将高温煤沥青和浸渍剂沥青在不同压力下炭化,在2500℃下对所得沥青炭进行石墨化处理;测试了所得沥青炭的体积密度、开孔率;利用扫描电子显微镜(SEM)观察了所得沥青炭的显微结构;利用XRD检测了不同炭化压力所得沥青炭石墨化处理后的石墨化度。结果表明:随着炭化压力的增大.沥青炭的体积密度增大而开孔率减小;随着炭化压力的增大沥青炭显微结构有从流线型向镶嵌型和域型转变的趋势:流线型结构沥青炭石墨化度较高;沥青中QI组分也会影响沥青炭的显微结构。  相似文献   
992.
许小云  刘瑾  樊建明 《应用化工》2005,34(6):325-328
综述了二水硫酸钙结晶过程的最新研究进展,从各个角度介绍了外部条件对硫酸钙结晶的影响,以达到对二水硫酸钙结晶的各种技术有一种比较客观综合的理解和认识,对未来二水硫酸钙结晶过程的研究方向作了探讨。  相似文献   
993.
Several novel and some previously known, mostly sugar-based, surfactants have been synthesized and some of their surface properties have been characterized and compared with those of commercial nonylphenol ethoxylates. The surfactant solubility in water, ethanol, and dodecane was studied. The properties of these compounds as emulsification agents in systems composed of the surfactant with water/isopropyl myristate, water/rapeseed oil, and water/dodecane are presented. The aqueous solubility of the surfactants follows the general trend expected from their hydrophilic-lipophilic balance according to Griffin (HLBG), but it is also clear that the nature of the headgroup and the structure of the nonpolar part affect the solubility in a manner not aptured in the standard HLBG concept. An ester or amine group as the connecting unit between the hydrophile and the hydrophobe produces a more water-soluble surfactant than the corresponding amide derivative. Some effective emulsifiers were found. For instance, the surfactants with a dehydroabietic nonpolar group appear to be promosing emulsifiers. Most sugar-based surfactants were able to form macroemulsions of up to around 2 wt/vol% of oil. The stability of many of these amulsions was very high, extending for months.  相似文献   
994.
The papers deals with formation of vortex structures during combustion of a fuel gas–air mixture injected vertically down through a hole in a flat plate. It has been established that the shape, position, and number of vortex cells are determined by the flow rate and composition of the fuel mixture. It is shown that as the flow rate increases from the minimum critical value for which a vortex structure arises, the number of vortex cells decreases from five or six to one. A further increase in the gas flow rate leads to transition to turbulence of the combustion product flow. The presence of a vortex structure increases the critical Reynolds number at which the flow becomes turbulent. Reverse transition to the structure with an increased number of vortex cells occurs with a delay in the gas flow rate (gas discharge hysteresis). Variation in flow rate is accompanied by bifurcation of the number of vortex cells.  相似文献   
995.
Polymeric materials are being developed with renewable resources to promote industrial progress with environmentally friendly technologies. For this reason, polyurethane samples were prepared with 4,4′‐diphenylmethane diisocyanate (NCO/OH = 1), eucalyptus tar pitch (biopitch), castor oil as a polyol, and dibutyltin dilaurate as a catalyst. These materials were reinforced with different contents of short sisal fibers (0, 2.5, 5.0, 7.5, and 10.0%) and were prepared by resin‐transfer molding. The composites were characterized by IR absorption spectroscopy, thermal analysis (thermogravimetry and differential scanning calorimetry), impact resistance, scanning electron microscopy, and water absorption resistance. These materials showed hydrophobic characteristics, despite the addition of sisal fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3797–3802, 2003  相似文献   
996.
可伸缩铰支管接头简介   总被引:1,自引:0,他引:1  
本文指出了埋入地下的刚性管接头连接的管道易出现的问题及为解决这些问题而发明的可伸缩铰支管接头的特点及结构。  相似文献   
997.
介绍和评述了诊断含能材料热分解和推进剂燃烧波结构的方法、仪器和研究进展,以及含能材料和推进剂热分解和燃烧波结构的研究结果,探讨了燃烧机理研究方法的发展方向。提出需要不断完善和更新推进剂燃烧的诊断方法,以获得更为全面的接近真实条件下推进剂燃烧的有效信息。附参考文献14篇。  相似文献   
998.
黄原胶的结构、性能与应用   总被引:18,自引:0,他引:18  
简要介绍了黄原胶的结构、性能;综述了它在化学工业及食品工业中的应用;重点论述了黄原胶作为悬浮剂、乳化剂、稳定剂、增稠剂等在日用化学工业中的应用,具有优良的悬浮性、乳化性、流变性、热稳定性及酸、碱稳定性;最后指出了我国在黄原胶应用方面的不足及以后的发展方向。  相似文献   
999.
在共沉淀法合成磁流体的基础上,用悬浮缩聚法制备了磁性漆酚缩甲醛微球,并用X射线粉末衍射、透射电镜和热重分析等对微球进行结构表征。实验结果表明,Fe3O4磁流体的粒径为纳米量级,纳米Fe3O4粒子能够提高复合物的热性能。该微球粒径约1mm,是核壳结构,具有良好的耐溶剂性和耐热性。  相似文献   
1000.
The Ouroboros Model offers a novel cognitive architecture with an algorithmic backbone of iterative and self-referential processing. All memory content is organized into meaningful pieces of data, i.e.,chunks and schemata, which are laid down as a kind of snapshots of all activations at a relevant point in time. This entails a grainy structure of memory content. Whereas a core process of "consumption" analysis can naturally be defined taking advantage of this parcellation, it necessitates interpolation for fine nuances, especially for the representation of intermediate values during transients. It is argued that, in the vertebrate brain, essential interpolation functionality is provided by the cerebellum. Findings concerning movement control and perception as well as the involvement of the cerebellum in more abstract, cognitive, tasks can be interpreted as reflecting a function of the cerebellum as a co-processor, i.e., a general-purpose interpolator. The cerebellum is thus boosting representations in cerebral cortex areas, which are reciprocally connected with cerebellar cortex areas. In this paper, it is sketched how the new "interpolator hypothesis" can explain manifold observations, effectively subsuming previous theories of the function of the cerebellum. Directly relating to the BICA challenge, a general-purpose interpolator is postulated as an efficient device providing fine-grained resolution for the representation of diverse content, potentially useful in any cognitive architecture.  相似文献   
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