预活化时间对稻壳基活性炭结构和电化学性能的影响

以农业废料稻壳为碳源,氢氧化钠为活化剂,采用干法两步活化法制备活性炭。X射线衍射分析表明该法能有效去除稻壳中的灰分,提高活性炭的孔隙率。扫描电镜结果表明,活性炭具有发达的孔隙结构。以活性炭制备超级电容器的电极,并组装成扣式电容器。采用恒流充放电、循环伏安、交流阻抗等测定超级电容器的电化学性能,并着重探究了预活化时间对活性炭的结构及电化学性能的影响。结果表明,预活化时间为120 min的活性炭的比电容最大,在0.25 A/g电流密度下,可达219F/g,经过1 000次循环后,其电容保持率仍达85.4%。这表明活性炭电极具有较理想的电容特性,且循环性能稳定。     

磷渣对混凝土性能影响的研究

通过研究掺入磷渣后的混凝土拌合物性能、力学性能、热学性能、变形性能和耐久性能,认为磷渣能代替粉煤灰作为混凝土的掺合料。本研究结果为缓解粉煤灰供应压力,充分利用磷渣资源提供一定的参考依据。     

纳米晶等温生长新模型

INTRODUCTION Nanocrystallites with an average grain size of less than 100 nm have attracted considerable scientific interest because of the improvements in a variety of properties resulted from grain-size refinement in the nanometer scale.The investigation of the thermal stability or grain growth behavior is therefore important from the technological point of view as well as for the purpose of scientific study.     

活性炭在防治大气污染方面的应用研究与展望

作为一种优良的吸附剂,活性炭在防治气体污染物方面得到了广泛应用。结合国内外相关研究进展,评述了活性炭的结构性能及在大气污染中的应用。分析表明,大量的微孔可提供充足的活性位,有利于活性炭吸附分子直径较小的气体污染物。同时,阐述了其现状及发展前景,指出利用废弃物制备活性炭意义重大。     

“无机材料工艺学”课程教学改革研究与实践

《无机材料工艺学》为无机非金属材料工程专业的主干课和核心专业课,在无机材料人才培养中处于重要的地位,进行与新的人才培养方案及教学体系相适应的《无机材料工艺学》课程建设是无机非金属材料专业教学改革中的一项重要内容。本文从课程体系、教学内容、教材建设、实验与实践教学、教学方法与手段等方面总结了《无机材料工艺学》课程教学改革研究和实践。     

ZSiO4/Cd(S1-xSex)包裹色料的水热合成

采用水热法成功合成了ZrSiO4/Cd(S1-xSex包裹色料,通过x射线衍射、透射电子显微镜、红外光谱及色度测试研究了合成条件对色料性能的影响.结果表明:当水热反应温度为180℃,保温时间为10h,ZrSiO4/Cd(S1-xSex=2时,色料具有较好的结晶度和色度,粒子细小且均匀,其尺寸分布为20～30nm.     

ZrSiO_4/Cd(S_(1–x)Se_x)包裹色料的水热合成(英文)

采用水热法成功合成了ZrSiO4/Cd(S1–xSex)包裹色料,通过X射线衍射、透射电子显微镜、红外光谱及色度测试研究了合成条件对色料性能的影响。结果表明:当水热反应温度为180℃,保温时间为10h,ZrSiO4/Cd(S1–xSex)=2时,色料具有较好的结晶度和色度,粒子细小且均匀,其尺寸分布为20～30nm。     

Grain growth kinetics of SnO<Subscript>2</Subscript> nanocrystals synthesized by precipitation method

Monodispersed spheroidal SnO₂ nanocrystals with the grain size of 8–30 nm were synthesized by the precipitation method using SnCl₄·5H₂O (stannic chloride hydrate) as raw materials. Differential scanning calorimetry/thermogravimetry (DSC/TG), X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to characterize the structure of SnO₂ nanocrystals. The influences of the calcination temperature and time on the lattice constant, the lattice distortion and the grain size of SnO₂ nanocrystals were discussed based on the XRD results. The grain growth kinetics of SnO₂ nanocrystals during calcination process was simulated with a conventional grain growth model which only took into account of diffusion and with a new isothermal model proposed by our group, which took into account of both diffusion and surface reactions. Using conventional model, the grain growth rate constant of SnO₂ crystals is 1.55×10⁴ nm⁵/min with a pre-exponential factor of 5 and an activation energy of 108.62 kJ/mol. Compared with the convention model, the new isothermal model is more realistic in reflecting the grain growth behavior of SnO₂ nanocrystals during the calcination process. This indicates that the grain growth of SnO₂ nanocrystals is controlled by both diffusion and reaction factors, and the effect of surface reactivity on the grain growth of SnO₂ nanocrystals could not be ignored. A combined activation energy estimated with the new isothermal model is 53.46 kJ/mol.     

纳米A12O3颗粒的制备及其悬浮液的分散稳定

以异丙醇铝为原料，甲苯为溶剂，氨水为pH值调节剂，采用溶胶-凝胶法制备了含有α和θ2种晶型的高纯纳米A12O3颗粒．产物经XRD，TEM以及BET测定和杂质含量分析，研究了不同pH值、分散剂种类及其用量对A12O3悬浮液分散稳定性的影响．研究结果表明：产物的主晶相是θ，次晶相是α；A12O3颗粒粒径为10～20nm，粒子呈球形或类球形，粒子尺寸分布较均匀，比表面积为82．31m^2／g；纯度≥99．95％；配制稳定的A12O3 CMP浆料的合适工艺条件为：在A12O3固含量为6％的浆料中，加入质量分数为10％的H2O2作为氧化剂，体积分数为0．99％的异丙醇胺作为分散剂，同时将浆料的pH值控制在3～4，能得到长时间不沉降的稳定浆料．     

Synthesis of ZnO doped ceria nanoparticles via azeotropic distillation processing

The synthesis of nano-sized ZnO-doped CeO2 of 20 nm in crystal size by a coprecipitation technique was investigated by different scanning calorimetries/thermalgravimetrics（DSC/TG）, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and ultraviolet （UV） absorbance. Azeotropic distillation processing was performed to effectively eliminate the residual water inside the as-prepared precipitate. Doping of ZnO results in the formation of solid solution. The crystal size of the nanoparticles increases with the increase of the doped ZnO amount, the calcination temperature and time. Doped CeO2 nanoparticles show excellent visible-light property and ultraviolet-absorption activity. Doping of ZnO doesn＇t not weaken the UV-shielding property of ceria.