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电气石表面TiO2微孔空心球簇的制备及光催化活性研究 总被引:10,自引:0,他引:10
用溶胶-凝胶技术在紫铜表面制备含电气石矿物粉末的TiO2复合薄膜,研究薄膜的制备方法、显微结构及其光催化活性.用SEM技术研究电气石-TiO2复合薄膜的微观结构和电气石表面TiO2的显微结构,测量了TiO2空心球直径、TiO2空心球簇大小,同时用电子探针对电气石-TiO2复合薄膜中的TiO2空心球簇表面及球簇周围TiO2膜进行了成分分析;并用电气石/TiO2复合薄膜光催化降解甲基橙水溶液,研究电气石对TiO2薄膜光催化活性的影响.结果发现,紫铜表面上电气石微粒均匀分布在TiO2薄膜中,且在电气石微粒表面可形成TiO2微孔空心球和微孔空心半球构成的微孔空心球簇,空心球和空心半球的平均粒径为2μm;经紫外线照射180min后,与不含电气石的TiO2薄膜相比,含电气石0.5;的TiO2复合薄膜对甲基橙的光催化降解率可提高31.9;,电气石可以明显提高TiO2薄膜的光催化活性. 相似文献
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以紧密堆积的三级配SiC颗粒(粒径为325 μm、212 μm、80 μm,质量比为17∶7∶1)为基础配方,将Owt;、1wt;、2wt;、3wt;和4wt;且粒径为5μm的SiC微粉添加到SiC耐磨材料中,经1600℃保温3h烧制,研究了SiC微粉添加量对SiC耐磨材料结构和性能的影响.结果表明:SiC微粉可促进SiC耐磨材料的烧结致密化,并改善其力学性能,当其添加量为3wt;时,试样的综合性能较优,其体积密度和显气孔率分别为2.63 g/cm3和7.62;,硬度、抗折强度和磨损量分别为2458 HV、183 Mpa和0.26 g/min.SiC耐磨材料烧结性能和力学性能的提高可归因子SiC微粉充填在SiC颗粒间,缩短了扩散传质路径,且较小粒径的SiC微粉具有较大的表面能,烧结时易于晶粒重排,保证了烧结网络的连续性,增大了颗粒间的结合程度. 相似文献
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研究了在复合电铸过程中,当其它工艺参数一定时,复合电铸层的沉积速率及其厚度随时间的变化趋势, 以及复合电铸层表面微观形貌随电沉积时间的变化趋势.测定了复合电铸层的组织成分,并就纳米颗粒在复合电铸层表面和横截面上分布的均匀性进行了评价.结果表明,复合电铸层表面平整,组织均匀致密,其组成主要是镍和所复合的纳米颗粒,纳米颗粒较为均匀地分散在复合电铸层中. 相似文献
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高效晶体硅太阳电池是光伏领域的热门研究之一,提高晶体硅太阳电池的转换效率是光伏研究者的重要研究方向.降低电池背面反射率是提高晶体硅电池转换效率的有效方法之一,实验采用激光掺杂制作选择性发射极,并利用槽式湿法碱抛光技术,去除发射极表面的重掺杂区,降低载流子在电池发射极表面区域的复合,提高载流子的有效寿命达到抛光效果,并最终提升电池转换效率.结果表明:硅片经过抛光处理后,减少了作为复合中心的悬挂键,降低了表面复合速率.发现了高反射率增强了光的反射,反射回电池内部的光被再吸收,提高了光的利用率.这是造成短路电流提升的主要原因.表面掺杂浓度的降低以及表面重掺杂区尺寸的减小将有效抑制载流子在发射极区域的俄歇复合,提高载流子的有效寿命. 相似文献
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为提高莫来石质浇注料耐碱侵蚀性能,以焦宝石骨料、氧化铝微粉、二氧化硅微粉和铝酸钙水泥为主要原料,添加一定数量碳化硅,制备莫来石质耐碱浇注料.通过XRD、XRF及SEM方法对热处理后和碱侵蚀后试样的物相组成、化学组成和微观结构进行表征,重点研究添加剂碳化硅对莫来石质浇注料组成、结构及耐碱侵蚀性能的影响.结果表明:莫来石质浇注料经1 100℃热处理后试样主要矿物为莫来石和鳞石英,随着碳化硅加入量增大,热处理后浇注料试样常温强度略有减小,碳化硅添加剂表面氧化促进了浇注料中莫来石化程度的提高.氧化钾对莫来石质浇注料具有强溶剂效应,高温下易于与浇注料中的氧化铝和二氧化硅形成高温液相,形成连续性的碱侵蚀,低温条件下以钾长石形式存在.引入碳化硅一定程度上阻塞了碱侵蚀过程中高温液相通道,降低了莫来石质浇注料碱侵蚀速度. 相似文献
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以表面缺陷较多的金刚石微粉为实验原料,用混合强酸对其表面进行处理使其羟基和羧基化.然后采用化学沉淀法制备出金刚石/Fe3 O4磁性聚集磨料.用XRD、SEM、EDS、IR、Raman、VSM等检测方法对样品的结构、形貌、元素组成和磁性能进行了表征.结果表明,Fe3+与金刚石表面的含氧基团的络合作用,使金刚石微粉表面被Fe3 O4颗粒包裹,形成不规则类球形金刚石/Fe3 O4磁性聚集体.当金刚石加入量占理论生成总固体量的9.4wt;时,磁性聚集磨料展现较高的磁性能.其饱和磁化强度(Ms=60.8 emu/g)与同等工艺制备的纯Fe3O4样品(Ms=66.3 emu/g)接近. 相似文献
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《Journal of Non》2007,353(30-31):2852-2860
The reactions taking place at high temperature during a mold flux slag crystallization are studied in details by means of high temperature powder diffraction. Two heating ramps were performed in two different temperature ranges, showing the formation and decomposition of various phases during the whole crystallization process. A full isothermal kinetic analysis was carried out for the formation of cuspidine, whose results were compared with non-isothermal data provided by DTA analyses, showing a good agreement between the two techniques. 相似文献
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对碲化镉晶体进行了光学加工,利用两台测量精度为1″的光学比较测角仪和一块平行度优于1″的平行平晶测量了其平行度,并且和光学加工过程中采用激光平面干涉仪测得的氟化钙陪片的平行度进行了比较,分析了这种测量方法的误差来源及大小.结果表明:采用此方法测得的碲化镉晶体的平行度和采用激光平面干涉仪测得的陪片的平行度相差不超过3″;此方法的误差主要来自于光学比较测角仪的测量误差和平行平晶的平行度误差,总误差最大不超过5″,能够满足碲化镉晶体平行度测试的精度要求. 相似文献
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通过合理调配CaF2和CaO的加入量,在1120℃温度下制备出了具有较好光泽度的透明无铅硼釉及较好白度的硼乳浊釉.用单因素法探讨了CaO和CaF2含量对低温无铅硼釉釉面透明度(乳浊度)、光泽度、流动性的影响.结果表明,CaO可以抑制无铅硼釉的分相,降低釉的乳浊度,提高透明度,增加流动性,但含量多时会降低釉的光泽度.CaF2比CaO具有更强的助熔作用,可以使石英充分熔融,但同时由于釉粘度的降低,会析出钙长石和硅灰石晶体,降低釉的透明度. 相似文献
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透明SiO2-Al2O3-CaO-CaF2 微晶玻璃中Tb3+的发光性能研究 总被引:2,自引:1,他引:1
通过对1.0 mol;Tb2O3掺杂45SiO2-20Al2O3-10CaO-25CaF2玻璃进行热处理制备出透明微晶玻璃,经XRD分析微晶玻璃内析出了大小约为27 nm 的CaF2颗粒.并分别在紫外和X射线激发下研究了Tb3+在基质玻璃和透明微晶玻璃中的发光行为.结果表明:微晶玻璃中CaF2纳米晶颗粒的析出有利于提高Tb3+的发光性能,紫外激发时,Tb3+的545 nm特征发光强度增强了4倍;而X射线激发时,Tb3+的545 nm特征发光强度增加了3.5倍. 相似文献
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Crystallography Reports - The influence of additive coloring on the electrical conductivity of CaF2 crystals of special purity grade, used in photolithography optics, has been studied for the first... 相似文献
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Fluorine erodes continuous casters and pollutes the environment. In order to reduce the damage caused by fluorine, it is necessary and urgent to carry out research on fluoride-free mold fluxes. There has been little research done on the heat transfer performance of fluoride-free mold fluxes either domestically or abroad. The present work adopted TiO2 to take the place of fluorine in mold fluxes and studies its heat transfer performance. Heat flux simulation equipment was developed and the heat flux density of titanium-bearing mold fluxes containing TiO2 was measured; in addition, a solid slag film was obtained. The crystallization behavior and the change of activation energy for crystallization of the slag film was analyzed. Our results show that when the TiO2 content is increased, the heat flux density of fluoride-free mold fluxes decreases, the crystallization activation energy of mold fluxes is diminished and the crystallization ratio of mold fluxes increases, and the mineral phase of the slag film turns from akermanite into perovskite. When the basicity is increased, the heat flux of fluoride-free mold fluxes is reduced, the crystallization ratio of mold fluxes increases and the mineral phase of the slag film turns from unitary akermanite into the coexistence of two phases of akermanite and perovskite. Furthermore, the capability of fluoride-free and titanium-bearing mold fluxes to control heat transfer is better, so it can be expected to replace industrial slag containing fluorine completely. 相似文献
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Crystallography Reports - The electron diffraction investigation of two-component phases in the systems MF2–RF3 (CaF2–ErF3, SrF2–LaF3) and components of the systems CaF2, SrF2,... 相似文献
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B. A. Marinkovic Z. V. Zakula T. Sreckovic M. Tomasevic M. M. Ristic 《Crystal Research and Technology》1999,34(7):881-889
Tribophysical (mechanical) activation is used as a method for modification of physico-chemical properties of dispersed systems such as polycrystalline mixture of ZnO and Cr2O3 powders, obtained by conventional ceramic powder processing wet technique. Conventional mixtures were tribophysically activated by grinding in a vibro-mill with a continual regime in air. Conventional mixture and tribophysically activated mixtures, with activation times of 40 and 80 minutes, were thermally treated in non-isothermal and isothermal conditions. Solid-state reactions in non-isothermal conditions were examined by X-ray diffraction, differential thermal analysis and dilatometric measurements. The influences of tribophysical activation on solid-state reaction between ZnO and Cr2O3, during thermal treatment in isothermal conditions were investigated by X-ray diffraction line broadening theory. As a Fourier method for the pure physical line profile analysis a double-Voigt method is used. Mechanism of mass transport during solid-state reaction in ZnO-Cr2O3 system is proposed. 相似文献