油滴釉的仿制实验

本文以宋代油滴釉的化学组成参考依据,采用不同原料进行油釉的仿制实验。实验证明,油滴釉的形成首先取决于釉料的化学组成,然而,施釉厚度和烧成制度等更是决定油滴斑效果的重要因素。     

黄色油滴釉的研制

通过调整石英、苏州土、烧滑石、方解石、钾长石、牛骨灰、Fe2O3、TiO2等原料的含量制备出黄色油滴釉;并采用L9(34)正交试验法对黄色油滴釉配方进行了进一步的优化;研究了配方组成以及烧成制度对黄色油滴釉形成的影响。结果表明:钾长石、骨灰、Fe2O和TiO2均对黄色油滴釉有较明显的影响。TiO,是影响油滴呈现黄色效果的主要因素;钾长石则能降低釉的熔融温度和黏度;Fe2O。是釉面产生油滴的关键;而骨灰则有助于釉面产生分相效果,促使油滴的析出;油滴釉最佳烧成温度为1250°C,最佳高火保温时间为40min。     

仿宋代油滴釉的研制

本文从实验出发,对禹县地区挖掘出的宋代油滴釉残片进行了研究、分析。对油滴釉使用的原料,坯、釉配方和油滴的形成及影响油滴显现的诸因素做了系统的总结。从而,开辟了传统名贵釉色——油滴釉利用现代窑炉烧制的新路子。实验结果表明,利用现代快速窑炉(隔焰推板窑)同样可以烧制油滴釉制品。油滴的发色(银灰色或棕红色)与MnO的引入有关。油滴天目釉,在我国古称“滴珠釉”,     

赤泥基低温红油滴釉的研究

为降低制备成本,有效利用工业废弃物,以赤泥作为氧化铁主要来源,在1120℃左右烧成,制备出了较为理想的低温红油滴釉。探讨了釉组成中ZnO、B2 O3、CaO、MgO、Fe2 O3、Al2 O3等氧化物含量对釉面光泽度、油滴形成的影响。研究发现,低温油滴釉的形成主要基于釉的分相;B2 O3、ZnO的引入不仅可促使釉分相,并能降低釉的熔融温度增加基础相的透明度,从而得到光泽度良好的低温油滴釉;调整CaO、Al2 O3等的含量可以控制分相的产生及分相的结构;Fe2 O3会富集在油滴状的微相中;ZnO、MgO对油滴釉的颜色有较大影响,增加ZnO的含量则油滴釉由黑色变为棕红色,增加MgO的含量则油滴釉由棕色变为黑色。研究了釉层厚度对油滴形成的影响,釉层厚度为1~1.5 mm时形成的油滴效果最好。     

油滴釉制作工艺的研究

在研制氧化气氛烧制油滴黑釉器的基础上 ,探讨了影响油滴釉形成的工艺因素。通过一系列试验 ,进一步验证了油滴釉在结晶过程中主要发生了液液分相 ;釉料的化学组成是油滴晶斑形成的先决条件 ;釉层厚度、烧成制度等是决定釉面效果的重要因素 ;油滴晶斑的呈色不仅与烧成气氛有关 ,还与着色氧化物的引入有关。     

隧道窑烧成铁系结晶釉的研制

通过对隧道窑烧成砂金石釉、油滴天目釉的研制，为在宜兴地区批量生产铁系结晶釉产品提供了依据。文中对试制过程中出现的一些情况作了简要的分析，有利于对铁系结晶釉产品的进一步研究。     

仿南宋油滴釉的研制

油滴釉是我国南宋时期发明的珍贵釉种之一，且有独特的装饰效果和极高的艺术价值。只要配方合理，工艺控制得当，采用普通制瓷原料对其仿制是可行的，并且取得了令人满意的结果。     

低温快烧自微晶乳浊釉的研究

采用ＳＥＭ、ＥＤＸ、ＸＲＤ等手段,了ＫＮａＯ－ＭｇＯ－Ａｌ２Ｏ－Ｂ２Ｏ３－ＳｉＯ２系全熔块乳浊釉的形成规律,指出釉层中均匀分布的大量ＭｇＳｉＯ３微晶是釉面乳浊的原因。组成中Ｂ２Ｏ３含量愈高,釉熔体的析晶倾向愈大。少量Ａｌ２Ｏ３则可以降低釉熔体高温粘度,抑制析晶,改善釉面面白我泽度。在釉烧过程中,析晶继续进行,Ｂ２Ｏ３含量的增加使基质釉玻璃的成熟温度降低。设计合理组成有快烧工艺,可得到釉面综合质量良     

窑变釉工艺品的开发研究

本文是在秉承建窑兔毫、油滴釉制作烧成的基础上,拓展研究窑变色釉的烧成工艺,并尝试开发现代工艺品制作。让古代窑变釉呈现出新的艺术魅力,并为进一步推进市场寻求商机。     

珠光堆釉的研制

使在一次性低温烧成制度下，釉表高度玻化的生釉保持施釉时高堆立半球状，并使其堆釉群体闪灼出柔和清亮的光泽，即珍珠光泽，务必使使釉堆在形成珍珠般堆釉的烧成过程中具有相当大的表面张力和坯釉共熔结构等具备一定的高温粘度，以达到熔融而不塌釉、流釉，且似半球状堆釉紧扣胎体，宛如无数大小珍珠争相闪耀。     

氧化铁析晶过程及烧成制度的探讨

通过理论分析与动态观察等试验方法研究了铁结晶釉中氧化铁的析晶过程，确定了“阶梯式”升温的烧成工艺制度，为铁系结晶釉的生产提供了一定的理论基础。     

乙炔电还原制备乙烯的反应机理

选择钯电还原乙炔制备乙烯并通过气相色谱法对产品进行表征,利用第一性原理计算方法探讨乙炔在催化剂Pd (111)表面的吸附情况,采用循环伏安法研究钯电极在硫酸溶液中还原乙炔的电极过程,测定电极的稳态极化曲线并根据极化曲线推算Tafel斜率,重点结合表观传递系数及反应级数对拟定的乙炔电还原制备乙烯的反应机理进行验证。实验结果表明:乙炔分子在Pd (111)面上呈平行桥键构型时最稳定;钯电极在硫酸溶液中可将乙炔电还原为乙烯;得出了反应最可能的速率控制步骤。     

Chlorine reduction on platinum and ruthenium: the effect of oxide coverage

The rate and mechanism of the electroreduction of chlorine on electrochemically oxidised Pt and Ru electrodes has been investigated relative to the state of oxide formation. Current/potential curves for the reduction process in 1 M HCl solution saturated with Cl₂ have been obtained for electrode surfaces in various states of preoxidation with the use of the rotating disc electrode technique (RDE). In the case of chlorine reduction on platinum, the results indicate that adsorption of chlorine molecules with a subsequent rate determining electrochemical adsorption step is the dominant mechanism. The exchange current density seems to decrease linearly with the logarithm of the amount of surface oxide.Chlorine reduction on ruthenium is best described by a Heyrovsky-Volmer mechanism with the first charge transfer reaction as the rate determining step. The Krishtalik mechanism incorporating adsorbed OCl⁺ intermediates is also able to describe the reaction successfully. The reaction order is constant for all oxide coverages while the exchange current density apparently moves through a maximum at intermediate oxide coverages (∼100 mC cm⁻²).The results show that the electrocatalysis of the cathodic reduction of chlorine is very sensitive to the state of the oxide film on the surface.     

The effect of reaction conditions on the urethane prepolymer formation

Summary In the two step synthesis of urethane copolymers, most statements from the literature assume that all of the diisocyanate will be used up in the formation of the isocyanate-endcapped polyol. However, a computerized simulation indicated the formation of three kinds of product.Synthetic experiments were conducted to study the first step of this reaction. It was found that not all of the intermediates reacted in the first step of the synthesis. Some diisocyanate remained unreacted and a polyol dimer was formed. Two different polyols were used in this study. When a polyol has primary hydroxyl groups on each end, more unreacted diisocyanate was present at the completion of the reaction than when the polyol has a primary and a secondary hydroxy end. The investigation of the solvent effect revealed that the solvent used had little effect on the prepolymer formation. The study of the temperature effect showed that more unreacted diisocyanate was obtained at the higher temperature for the 4,4-diphenylmethane diisocyanate/polytetramethylene glycol reaction.     

Preparation and properties of high molar mass nylon-4,6: a new development in nylon polymers

The preparation, in a two-step process, of poly(tetramethylene adipamide) (nylon-4.6) has been studied. The first step involves precondensation of tetramethylene-diammonium adipate (nylon-4,6 salt) with water as solvent. A kinetic model is postulated that describes the prepolymerization by a second order amidation reaction with formation of pyrrolidine end-groups as a side reaction. In the second step, prepolymer powder is subjected to solid state polycondensation to achieve a sufficiently high molar mass. High molar mass nylon-4,6 (Stanyl¹) exhibits a very high melting temperature (about 290°C) and high crystallinity, which makes it an attractive material for applications at high temperature where dimensional stability is a strict demand, such as applications in industrial yarns and engineering plastics.     

Kinetic investigation of the carbothermal reduction of an Iranian clay

The kinetics of the carbothermal reduction of clay under argon atmosphere has been investigated by the X-ray diffraction method. The clay-carbon (excess) mixture was formed into 2 cm diameter disks of different thicknesses. Experimental data evidences the significant effect of sample thickness on the reaction rate at 1400 °C. Decreasing thickness promotes mullite dissociation and formation of SiC and alumina powders. Mathematical modeling of the reaction system showed the gas diffusion in the Knudsen regime through the pellet to be the rate controlling step. Diffusivity of CO and reacted core tortuosity factor have been calculated.     

Liquid-Phase Low-Temperature and Low-Pressure Methanol Synthesis Catalyzed by a Raney Copper-Alkoxide System

Current CuZnO methanol synthesis technology may be improved by development of a catalyst allowing a “once through” methanol synthesis step. A Raney copper/alkoxide catalyst has been reported in the patent literature operating at 50 bar and 120 °C. We report here the effect of temperature, pressure, Raney copper concentration and CH₃OK concentration by orthogonal array design on this catalyst system. A synergistic effect on catalyst activity and methanol formation has been observed between CH₃OK and Raney copper.     

Solution of final stages of polyethylene terephthalate reactors using orthogonal collocation technique

The formation of polyethylene terephthalate (PET) has been modeled to have reactions with monofunctional compounds, redistribution, and cyclization reactions in addition to the usual polycondensation step. In the final stages, the overall polymerization is mass-transfer controlled and solution of the reactor performance equations have been determined through the orthogonal collocation technique. This technique is found to be considerably more efficient for PET reactors compared to the finite difference method; the use of ten collocation points gives results which are close to the exact solution.     

Alcohol Interaction with Zirconia Powders

The mechanism by which alcohol washing of ceramic powders produces "soft" agglomerates has been investigated by studying the interaction of ethanol with hydrous ZrO₂ powders using Fourier transform infrared (FTIR) spectroscopy. Unambiguous evidence of ethoxide formation has been found, which apparently prevents bond formation between adjacent particles and thus the formation of "hard" agglomerates.     

腈纶生产中聚合流程的探讨

以聚合流程为主,宏观地对腈纶NaSCN为溶剂的“一步法”与“二步法”生产进行比较,并对“一步法”可进行的改进之处作了探讨。