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The increase in refractoriness referred to here is usually termed freezing. The study was undertaken to overcome the tendency of pyrometric cones to set or freeze when subjected to prolonged heat treatment when the temperature is more or less fluctuating. The work includes a study of the freezing tendency of some natural clays, of several pottery bodies, and of pyrometric cones. A body was developed that does not freeze under the treatment that produces the phenomenon in the other materials tested but the cause is not established. 相似文献
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介绍煤化工装置空分氧泵变频器的电气控制原理,分析氧泵变频器因系统晃电而导致跳停的原因,通过对变频器增加直流支撑装置,确保空分氧泵变频器稳定运行。 相似文献
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本文介绍了日本在煤气化联合循环发电、煤加氢热解,煤加氢液化和水煤浆等煤转化技术方面是最新进展及中度厂部分试验结果,同时也介绍了日本最近提出的煤气化联合燃料电池新转化工艺的方案。 相似文献
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《Journal of aerosol science》1999,30(3):279-288
A technique based on fluorescence scattering by microdroplets has been shown to be capable of measuring instantaneous rates of photochemical reactions in microdroplets. The technique has been applied to study trans -to-cis photoisomerization of thioindigo dye in single solution droplets suspended in an electrodynamic balance. Through an analysis it is shown that the concentration distributions of isomers remain uniform in a droplet under the experimental conditions; thus, the scattered fluorescence intensity from the droplet is proportional to the concentration of solely fluorescent trans isomer molecules. The steady-state scattered fluorescence intensity versus incident laser power data have been used to interpret the kinetics of the reaction. The results show that the rate constants can be determined from the scattered fluorescence intensity versus time data. The technique is particularly suitable when only one species fluoresces in the photo-reactive wavelength range while other species present in a droplet do not. 相似文献
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介绍了美国近年来在水泥应用方面的研究动态。其基本方针是从材料科学,尤其是脆性材料理论出发,通过改变水泥基材料的组成和改进成型方法,使硬化水泥石的结构趋于合理,从而大幅度提高水泥的各种性能,最终达到部分取代陶瓷、金属、塑料和木材等其它材料的目的。这种新型的水泥材料被称为ACBM(Advanced Cement Based Materials)。美国已建立了ACBM研究中心,并出版了名为“Cementing The Future”的专门刊物来介绍这方面的科技新信息。 相似文献
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描述了江苏省塑料行业的概貌,介绍了江苏省塑料行业各领域(如热塑性塑料、热固性塑料、降解塑料、成型加工、塑料制品、塑料助剂等)取得的技术成果、研究进展和生产装置水平。 相似文献
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Iva Filkova 《Drying Technology》2013,31(4):627-634
Research and development of drying processes and equipmect has a long tradition in Czechoslovakia (1). There are at least 10 top reoearch centers where drying of varicus materials has been studied. Remarkable attention to drying theory and application is also paid at Czechoslovak universities which yields numerous theses dealing with various aspects of the drying process. The total of 52 M.Sc. theses oriented to drying and/or dryers had been published in the last decade. Moreover, 22 Ph.D. theses were carried out in the same period. This represents an important source of theoretical and experimental results. However all theses had been mitten in the Czech or Slovak language, and therefore their wide international application is rather limited. They are summari-zed in the following list. 相似文献
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Iva Filkova 《Drying Technology》1985,3(4):627-634
Research and development of drying processes and equipmect has a long tradition in Czechoslovakia (1). There are at least 10 top reoearch centers where drying of varicus materials has been studied. Remarkable attention to drying theory and application is also paid at Czechoslovak universities which yields numerous theses dealing with various aspects of the drying process. The total of 52 M.Sc. theses oriented to drying and/or dryers had been published in the last decade. Moreover, 22 Ph.D. theses were carried out in the same period. This represents an important source of theoretical and experimental results. However all theses had been mitten in the Czech or Slovak language, and therefore their wide international application is rather limited. They are summari-zed in the following list. 相似文献
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Abstract Moisture distribution in spheres of potato (Solanum tuberosum) and yam (Dioscorea japonica) tubers during microwave drying was investigated. Moisture variation at various locations within the samples was experimentally determined for different drying times. A numerical simulation model was developed based on a modified form of Lambert's law for microwave penetration in spheres and on moisture transfer in both liquid and vapor phases. This model was used to study various factors influencing moisture distribution. Moisture profile during microwave drying was strongly influenced by non-uniform microwave energy distribution within the foods. The core moisture contents were lower than other parts of potato and yam spheres of the various sizes tested in this study (2.6 cm to 6.0 cm diameter). The sphere radius to microwave penetration ratio (2αro) was an important parameter affecting the moisture profile in spherical foods. For 2αro of less than 2.0, the moisture content in the center of potato and yam spheres was markedly lower than the rest of the food, but for 2αro between 2.5 and 4, moisture contents at the center and close to the surface were lower than the average moisture content. 相似文献
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