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研究了铬酸酐热分解制备高性能红外反射氧化铬绿颜料,在优化现有铬酸酐热分解工艺的基础上,详细探讨了掺杂制备红外反射氧化铬绿颜料的工艺条件和相关机理。借助UV-vis-NIR、FT-IR、SEM、XRD和CIE-L*a*b*等手段发现:在铬酸酐热分解过程中,不同的热分解温度导致粒径变化,从而影响红外反射率;优化的制备工艺条件(热分解温度1250℃、热分解时间0.5 h)下,氧化铬绿的红外反射率达到90%。在掺杂过程中,V2O5的添加可使氧化铬绿的最高红外反射率达到98%。随着V2O5添加量的增加,红外反射率先增加后减少;当V/Cr摩尔比为0.004时,红外反射率、电导率、介电常数都达到极值,三者呈现一致的规律性变化。初步机理探索表明,氧化铬本征导电类型为空穴导电,掺杂V2O5以后导电类型发生改变,伴随着电阻率的变化,氧化铬吸收和反射光子能力改变,从而影响红外反射性能。 相似文献
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制备了两种与传统陶瓷表面装饰的新技术(喷墨打印装饰技术)配套的新型墨水—黑色与黄色陶瓷表面装饰墨水。它们以陶瓷颜料为基本着色料,用溶胶—凝胶法制备,以连续式喷墨打印墨水的质量标准为参照标准。经测试,所制墨水的电导率、表面张力、粘度等理化性能完全符合喷墨打印墨水的要求,适用喷墨打印陶瓷装饰工艺的需要。研究了pH值、反应温度、硝酸用量、煅烧温度等因素对黄色墨水性能的影响。黑色墨水制成时为红棕色,煅烧后为黑色。黄色墨水的制备与实验条件有关,在一定条件下,黄色墨水制成时颜色与煅烧后颜色均为黄色。 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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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 miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure. 相似文献
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以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。 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