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凝胶注模成型制备BaNd2Ti5O14介电陶瓷的电学性能 总被引:2,自引:0,他引:2
讨论了用凝胶注模成型制备BaNd2Ti5O14介电陶瓷的过程。本实验以化学式为BaNd2Ti5O14的介电陶瓷为固相粉末,以丙烯酰胺(MBAM)为凝胶有机单体,用传统球磨的方法制备出了高固相、低粘度的陶瓷浆料(浓悬浮体);采用正交实验设计法,优化出生坯密度最大的配方。分析了凝胶注模成型与干压成型制备的BaNd2Ti5O14介电陶瓷的体积密度、结构均匀性以及电学性能不同的原因。结果表明:凝胶注模成型制备的BaNd2Ti5O14介电陶瓷具有体积密度高、结构均匀的特点。合理使用凝胶注模成型工艺可以提高陶瓷介电常数、降低介质损耗。 相似文献
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以Al2O3/Y2O3为烧结助剂,对凝胶注模SiC陶瓷进行了研究。讨论了埋粉组成和烧结温度对SiC陶瓷的烧成质量损失、线收缩、密度以及相组成的影响。当埋粉组成为SiC/Al2O3/Y2O3,在1950℃氮气氛中烧结1h时,制备了98%理论密度的SiC陶瓷。与传统的干压成型方法相比,凝胶注模成型工艺制备的SiC陶瓷坯体具有更高的烧成质量损失。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969. 相似文献
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A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses. 相似文献
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