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TeO2对氟铝酸盐玻璃性质和结构的影响 总被引:1,自引:0,他引:1
以10MgF2—20CaF2—10SrF2—10BaF2—15YF3—35AlF3氟铝酸盐玻璃为基玻璃引入不同含量的TeO2得到了新的氟碲铝酸盐玻璃.用差热分析方法研究了TeO2对氟铝酸盐玻璃性能的影响,通过拉曼光谱和红外吸收谱来研究玻璃的结构变化.差热分析表明TeO2的增加使玻璃开始析晶温度瓦升高,融化温度%降低,成玻璃能力增加.玻璃结构分析表明氟碲铝酸盐玻璃的结构中存在[FnAl-O—AlFn]、[TeO3]、[TeO2F]和[TeOF2]等多面体,这些多面体由F^-和O^2-离子连接.这种新的氟碲铝酸盐玻璃有着良好的成玻璃能力,在0.75~5.00μm范围内玻璃具有很高的透过率,是一种具有应用前景的新的红外光学玻璃材料. 相似文献
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为研究玄武岩纤维增强聚合物复合材料(Basalt fiber reinforced polymer,BFRP)筋与低碱度硫铝酸盐水泥混凝土的粘结性能,对共90个粘结试件进行中心拉拔试验,研究了筋材表面形貌、混凝土强度等级等因素对粘结性能的影响。试验结果表明:对筋材表面进行喷砂、缠绕纤维和螺纹处理能显著提高粘结性能,深螺纹环氧树脂BFRP筋与65 MPa低碱度硫铝酸盐水泥混凝土的粘结强度高达39.09 MPa,远大于光滑BFRP筋的13.32 MPa。强度等级对BFRP筋-低碱度硫铝酸盐水泥混凝土粘结试件的粘结强度的影响更明显,此外BFRP筋与低碱度硫铝酸盐水泥混凝土粘结性能高于普通硅酸盐混凝土。最后,通过Cosenza-ManfrediRealfonzo(CMR)模型和修正后的Bertero-Popov-Eligehausen(mBPE)模型)对BFRP筋-混凝土粘结试件的粘结滑移(τ-s)曲线进行拟合,发现CMR模型对粘结滑移曲线的上升段拟合效果较好,清晰准确地反映了其粘结-滑移本构关系,为研究BFRP筋增强硫铝酸盐水泥混凝土结构的力学性能提供了关键理论依据。 相似文献
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碱土铝酸盐掺二价铕离子磷光体的研究,应用和发展 总被引:11,自引:0,他引:11
本文综合评述了碱土铝酸盐掺二价铕磷光体的研究和应用前景,系统地回顾了该类磷光体研究开发历程和现状,并对该类磷光体的研究方向和应用前景进行了展望和预测。 相似文献
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本文综合评述了碱土铝酸盐掺二价铕磷光体的研究和应用背景,系统地回顾了该类磷光体研究开发历程和现状,并对该类磷光体的研究方向和应用前景进行了展望和预测 相似文献
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以净浆力学强度及Ca”和[A1O4]^5-离子溶出浓度为耐水性评价指标,研究了微组分石膏对磷铝酸盐水泥(phosphoaluminate cement,PALC)的影响,并通过S电位、XRD和孔结构等技术分析了其耐水性机理。结果表明:在浸水过程中,掺石膏和未掺石膏的磷铝酸盐水泥硬化浆体的力学性能均在不断提高,Ca^2+和[AIO4]^5-的溶出浓度不断减小。相比较而言,掺石膏的磷铝酸盐水泥试样在浸水早期的力学性能和离子溶出浓度较未掺的变化不大,但在长期浸水的过程中,前者力学性能明显高于后者,而Ca^2+和EAIO4]^5-溶出浓度却显著下降,这表明在磷铝酸盐水泥中掺入石膏,对其早期耐水性影响不大,但对长期耐水性的提高是十分有利的。 相似文献
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偶联剂KH和聚合物PVA在硫铝酸盐—MDF水泥中的作用机理 总被引:2,自引:0,他引:2
以硫铝酸盐水泥为基材,采用有机聚合物PVA,并且在MDF水泥中添加偶联剂KH,制备出抗折强度大于170MPa,抗压强度达240MPa的新型MDF水泥。同时,借助于X射线光电子能谱分析(XPS),红外光谱分析(IR)等测试手段研究了偶联剂KH和聚合物PVA的硫铝酸盐-MDF水泥中的作用机理。 相似文献
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Phosphor materials enable the optical frequency conversion to realize the full-color white emission light-emitting diodes (LEDs). So far much effort has been devoted to the design and discovery of novel LED phosphors for solid state lighting. In this review, firstly, we briefly describe several representative families of LED phosphors. Secondly, we propose the design methodology aimed at discovery of new phosphors with focus on the crystal structural considerations. Thirdly, we review the results of our work and other researchers on the recent advances in discovery and structural design of LED phosphors that exemplify the adopted strategies, including (1) design of the novel phosphors from the existed structural models, (2) discovery of novel phosphors from new crystal materials by doping and (3) structural modification of the known phosphors. The importance on the structure-property relations and recently reported methodologies involved in the crystal chemistry analysis for the discovery of LED phosphors, including mineral-inspired structural model design, exploratory crystal growth via single particle diagnostic approach, chemical unit cosubstitution, and so on, have been summarized in this review. We finally discuss the topics of structure-related active investigations and future opportunities for new and improved host materials for the color conversion applied in LEDs. 相似文献
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以马来酸酐(MA)和吲哚啉螺苯并吡喃(SP)为原料,在SrAl2O4∶Eu2+,Dy3+(SAO-ED)发光粉的表面进行复合包覆制备MA-SP-SAO-ED复合发光粉,探讨MA与SP的质量比、MA和SP的加入顺序对复合发光粉性能的影响,并用扫描电镜表征复合发光粉的表面涂层。结果表明,当MA和SP同时加入SAO-ED二氯甲烷溶液中,总加入量为SAO-ED发光粉质量的10%,且MA与SP的质量比为6∶1时,复合发光粉具有较好的耐水、光致发光和光致变色等性能;在SAO-ED发光粉表面包覆了均匀致密涂层。 相似文献
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C. H. Lin Bi-Shiou Chiou J. D. Lin 《Journal of Materials Science: Materials in Electronics》2002,13(12):705-711
Factors affecting the cathodoluminescent (CL) efficiency of phosphors include: morphology, size, stoichiometry, composition, and surface of the phosphors. In the design of phosphors for low-voltage operations, processes such as surface etching are used to enhance phosphor efficiency. In this study, zinc-activated ZnO phosphors were subjected to three processes: acid etching, ball milling, and/or ultrasonic vibration, and the effect of each process on the CL efficiency studied. It is found that the brightness of phosphors increases 40% after ultrasonic vibration followed by etching twice with 0.005 M HNO3. 相似文献
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蓄光型自发光材料及制品发展概况 总被引:2,自引:0,他引:2
论述了蓄光型自发光材料及制品的发展概况,对第一代和第二代蓄光型自发光材料的发展、典型代表材料及其特点、应用做了详细介绍,同时对蓄光型自发光材料的发展前景进行详细分析。 相似文献
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白光LEDs(White Light-Emitting Diodes, WLEDs)作为一种新型的固体照明光源, 相对于已有光源(白炽灯、荧光灯等)具有发光效率高、响应速度快、寿命长等优势, 在照明和显示领域有着广阔的应用前景。目前获取WLEDs最常用的方法是蓝光LED芯片激发YAG : Ce 3+黄光荧光粉以及紫外-近紫外芯片激发三基色荧光粉(RGB混合荧光粉), 相比于以上两种方式, 单基质WLEDs荧光粉由于能克服传统RGB荧光粉颜色再吸收及配比调控的问题, 获得较高的流明效率及较高色彩还原性而受到越来越多的关注。目前关于单基质白光荧光的研究已有大量文献报道, 涉及多种材料体系, 按照发光原理的不同, 可以将其地简单分为单离子激发体系、多离子激发体系以及不依赖于稀土离子发光的其他体系等。本文综述了单基质WLEDs荧光粉的研究进展, 指出了其发展中存在的问题, 并对未来发展趋势作了展望。 相似文献
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Yong Zhu Mingtao Zheng Jianghua Zeng Yong Xiao Yingliang Liu 《Materials Chemistry and Physics》2009,113(2-3):721-726
SrAl2O4:Eu2+,Dy3+ phosphors are chemically unstable against water. An encapsulation on the phosphors by direct reactions between triethyl phosphate and strontium aluminate was reported in this paper. Powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDS), thermogravimetric (TG) analysis, water resistance measurements, and photoluminescence (PL) spectrophotometry were used to characterize the phosphors before and after encapsulation. Experimental results showed that products of encapsulation reactions under an appropriate condition were in shape of nano-films on the phosphors. These thin films could effectively enhance both water resistance and photoluminescence of the phosphors. 相似文献
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Red phosphors are the traditional material used to improve the color rendering index (CRI) of white light emitting diode (WLEDs). In this paper, red quantum dots (QDs) were fabricated and coated on the blue LED chip to replace the red phosphors. By comparing the thermal performances of the CRI for the two WLEDs, we found that WLEDs with the encapsulation of yellow phosphors and red QDs exhibited higher CRI and lower sensitivity to temperature than those with the encapsulation of yellow and red phosphors. The CRI of WLEDs with yellow phosphors and red QDs was 90.9, and its range ability was only 0.3 when the environment temperature changed from 25 °C to 100 °C, while the CRI of WLEDs with yellow and red phosphors was as low as 81.8, and the change of CRI was 2.2 during the same temperature variation. 相似文献
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介绍了一种彩色PDP用蓝色荧光粉体的纳米化工艺,通过此方法,可以制备出比传统的PDP蓝色荧光粉体发光效率更高的纳米级蓝色荧光粉体,同时有效的降低了制备过程的烧结温度。制备的蓝色荧光粉体完全适用于PDP显示设备中。另外,纳米化的小颗粒也为进一步的表面包覆以防止衰减奠定了基础。 相似文献
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采用有机发光二极管(OLEDs)的有机半导体照明(有机照明)是绿色环保、健康安全的新型面光源,有望在固态照明领域得到广泛的应用。有机照明的发展是随着有机发光材料的不断进步而进步的。有机发光材料从最初的荧光材料发展到磷光材料以及最近提出的热活化延迟荧光材料,其性能在不断地提升。基于这些材料的白光OLEDs的性能也在不断提升。最早的白光器件基于荧光小分子材料,但是由于只能利用单线态激子发光,效率很低。随后磷光材料的引入使得白光器件的效率大幅度提升,但是由于蓝色磷光材料本身的稳定性问题,全磷光白光器件的寿命较短。为了结合荧光和磷光的优点,人们提出了荧光/磷光杂化的白光器件,这是目前最有前景的一类白光器件结构。目前针对有机照明的研究,已从早期只关注效率突破阶段,进入到综合提高效率和寿命阶段。从荧光白光、磷光白光以及荧光/磷光混合白光3个方面对有机照明的研究状况、发展趋势进行了介绍。 相似文献