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通过钕-铝系列色料合成实验,分析不同配比及不同矿化剂等对色料呈色效果的影响,确定最佳工艺方法。对实验结果进行XRD及色度分析,确定其主晶相为钕酸铝,试样的明度均在70以上,色彩鲜艳亮丽。 相似文献
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《Journal of the European Ceramic Society》2022,42(13):5820-5830
Cerium oxide doped with oxides of rare earth elements is a multifunctional material, a wide range of uses which is associated with its unique physicochemical properties. Phase diagrams of multicomponent systems are the physicochemical basis for the creation of new materials with improved characteristics.In this work, phase equilibria in ternary CeO2–La2O3–Dy2O3 and binary La2O3–Dy2O3 systems in the whole concentration range were studied. No new phases have been identified in these systems. An isothermal section of the phase diagram of the CeO2–La2O3–Dy2O3 system at a temperature of 1500 °С is constructed. No new phases have been detected in the system. It was found that in the studied ternary system solid solutions are formed on the basis of (F) modification of CeO2 with structure of fluorite type, monoclinic (B), cubic (C) and hexagonal (A) modifications of Ln2O3.In the La2O3–Dy2O3 binary system (1500–1100 °С) three types of solid solutions are formed: based on hexagonal modification A-La2O3, monoclinic modification B-Dy2O3 and cubic modification C-Dy2O3 separated by two-phase fields (A+B) and (B+C), respectively. The boundaries of the regions of homogeneity of solid solutions based on A-La2O3 are determined by compositions containing 35–40, 20–25, 15–20 mol% Dy2O3 at 1500, 1250, 1100 °C, respectively. From the obtained data it follows that the solubility of Dy2O3 in the hexagonal modification of lanthanum oxide is 39 mol% at 1500 °C, 23 mol. % at 1250 °C and 16 mol% at 1100 °C. The limits of existence of solid solutions based on monoclinic B-modification are determined by compositions containing 30–35, 65–60 (1250 °С), 35–40, 55–60 (1100 °С) 40–45, 70–75 (1500 °C) mol% Dy2O3.In the studied system, with a decrease in temperature from 1500° to 1100°C, there is a decrease in the solubility of La2O3 in the crystal lattice of cubic solid solutions of C-type from 16 to 10 mol%. 相似文献
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F. -T. Liou C. Y. Yang K. Hakim S. N. Levine 《Journal of Applied Electrochemistry》1983,13(3):377-382
Single crystal In2O3 shows promise as a photoanode for the decomposition of water. Because of various difficulties in the preparation of the single crystal material, two simple techniques were developed for the preparation of polycrystalline In2O3 anodes. One method involves the thermal decomposition of the nitrate while the other utilizes the chemical vapour deposition technique. Voltammograms and photoresponse spectra of these anodes are compared to the single crystal material. Among other observations, it is noted that the quantum efficiencies of the thermally decomposed films are comparable to the single crystal material. It is also shown that the on-set potential can be shifted to more negative values by forming the mixed oxide In2O3/Y2O3. 相似文献
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掌握Fe2+/H2O2体系O2的生成路径,可为避免H2O2无效分解,开发经济高效的Fe2+/H2O2体系利用技术指明方向。采用添加自由基捕获剂的方法,探究Fe2+/H2O2体系内各种自由基对O2生成速率的影响,进而确定O2的生成路径。结果表明:Fe2+/H2O2体系内不会产生大量O2-·,O2-·不是生成O2的主要反应物质;O2-·被全部捕获后,体系中仍产生大量O2-·,但此时无O2生成,证明生成O2的反应由·OH和HO2·两种自由基直接参与。分析认为反应·OH+HO2·-H2O+O2是体系内O2生成的主要路径。控制Fe2+/H2O2体系定向生成·OH,抑制HO2·的产生,是提高Fe2+/H2O2体系中H2O2利用率的有效手段。 相似文献
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以Al2O3, Fe2O3和Na2CO3为原料,对Na2O-Al2O3-Fe2O3系烧结过程中的反应行为进行了详细研究. 基于溶出率与时间、温度的关系,证明Na2O×Al2O3和Na2O×Fe2O3的生成反应动力学都服从Zhuralev-Lesokin-Tempelman模型,表观活化能分别为186.59和80.92 kJ/mol,表明Na2O×Fe2O3比Na2O×Al2O3在动力学上更易形成;Al2O3易与Na2O×Fe2O3反应形成Na2O×Al2O3和Fe2O3,在1273 K烧结30 min,所得熟料Al2O3溶出率达98.51%;Fe2O3对Na2O×Al2O3的形成有双重作用,在1273 K下可加速Na2O×Al2O3的形成,超过1323 K,促使Na2O×Al2O3分解成Na2O和b-Al2O3,且随着温度升高或时间延长,分解程度增高,从而导致熟料中Al2O3溶出率显著降低. 相似文献
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Activated hydrogen peroxide produces very reactive OH-radicals which destroy hazardous contaminants in water. The principles and different methods of activation are described. Results from laboratory studies show the numerous applications of this new technology. A successful scaleup of laboratory tests to an industrial level is discussed. Finally, a cost estimate for treating different types of water with hydrogen peroxide is presented. 相似文献
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Fong-Chang Sheu Cheng-Tsung Hong Wen-Long Hwang Cheng-Jec Shih Jung-Chung Wu Chuin-Tih Yeh 《Catalysis Letters》1992,14(3-4):297-304
A series of alumina aluminum borate (AAB) with various Al/B molar ratios were prepared by the coprecipitation method. The supported rhenium oxide catalysts with various contents of Re2O7 were also prepared by the impregnation method with perrhenic acid. The catalytic activity and stability of Re2O7/AAB catalysts for the reaction of propylene metathesis were tested in a fixed-bed microreactor. It was found that Re2O7/AAB is more active, stable and regenerable than Re2O7/Al2O3 for propylene metathesis. The optimum Al/B molar ratio was found to be in the range of 4–10. 相似文献
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A. H. Moinuddin Ahmed Lesley S. Dent Glasser 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1989,45(4):303-309
The compound 2BaO.Al2O3.5H2O has been synthesised and studied by infra-red, X-ray and thermal analytical techniques. The compound of approximate formula 2BaO.Al2O3.H2O forms as a dehydration product. The results are interpreted in terms of the known structure. 相似文献
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Desheng Feng Ming Li Sze Long Yee Yang Jiang Mao Chen Yi Peng Xiaodong Ma 《Journal of the American Ceramic Society》2021,104(9):4843-4853
V2O5-Fe2O3 and V2O5-TiO2 systems represent two important chemical systems with various applications, including energy, catalysts, and high-performance materials. In the present study, high-temperature phase equilibrium experiments were conducted at the temperature range of 670–1000°C in air. Electron probe X-ray micro-analyzer (EPMA) was used to analyze the microstructure and composition of the phases presented in quenched samples. Systematic experiments demonstrated that V2O5-containing systems should not be quenched by water-based quenching media. Phase diagrams in both systems were constructed, and the eutectic and peritectic points of the systems were confirmed and compared with previous studies. The present study improved the previous results and could be used as the base for thermodynamic modelings and further applications of the two systems. 相似文献
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Separation of phases was investigated in the hexagonal (rhombohedral) systems Al2O3−Cr2O3 and Al2O3−Cr2O3−Fe2O3. The binary system shows a miscibility gap with a Tc of 950°C; the miscibility gap for the ternary system was determined for a constant Cr2O3 content of 16.6 mol%. Dark field transmission electron microscopy of solid solutions annealed within the miscibility gap showed dark and light lamellas ∼50 to 200 Å thick. X-ray diffraction results for the solid solutions in the ternary system indicated that, in the early stages of annealing, broadening occurred only on (hkl) reflections where l≠0. There was no major change in the X-ray diffraction patterns of the annealed solid solutions in the binary system. Electron diffraction results indicated, however, that phase separation in both systems proceeded in the [001] direction. Solid solutions in the binary system separated very slowly; the separation could be enhanced hydrothermally. The mechanism of the separation of phases in both systems is spinodal and proceeds as follows: solid solution→intermediate modulated phase→equilibrium phases. 相似文献
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The purpose of this research is to evaluate the bactericidal capacity of different Advanced Oxidation Treatments (AOTs) based on ozone: ozone, ozone/hydrogen peroxide and ozone/titanium dioxide on a wild strain of Clostridium perfringens, a fecal bacterial indicator in drinking water. The dose of ozone consumed ranges from 0.6 mg L?1 min?1 to 5.13 mg L?1 min?1 depending on the process and on the sample. In the treatments combined with O3, H2O2 dose utilized is 0.04 mM and TiO2 dose, 1 g L?1. In order to evaluate the influence of natural organic matter and suspension solids over the disinfection rate, treatments are performed with two types of water – natural water from Ebro River (Zaragoza, Spain) and NaCl solution 0.9%. To achieve 4 log units of inactivation, 3.6 mg O3 L?1 is necessary in O3 treatment, 4.25 mg O3 L?1 in O3/TiO2 system and 2.7 mg O3 L?1 in O3/H2O2 after processing the natural water. In NaCl solution, to get the same inactivation, 0.42 mg O3 L?1 is necessary in O3 treatment, 1.15 mg O3 L?1 in O3/TiO2 system and 0.06 mg O3 L?1 in O3/H2O2 process. Even though the three treatments studied have a high bactericidal activity due to the number of surviving bacteria decreases to non-detectable levels, O3/H2O2 is the most effective system for eliminating C. perfringens cells in a lower contact time, followed by O3 and finally O3/TiO2 system. 相似文献
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The coefficient of linear expansion, glass-transition temperature, temperature at the orset of deformation (strain point), density. Young modulus, microhardness, crystallizability, and contact angle are studied as a function of the composition in RO–Y2O3–Al2O3–SiO2 (R=Ca and/or Mg) glass systems. The composition ranges for glasses (with strain point >900°C and coefficient of linear expansion of (32–45)×10–7°C–1) that can be used for soldering silicon-nitride ceramics were established.Translated from Steklo i Keramika, No. 12, pp. 5–7, December, 1996 相似文献