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51.
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One-dimensional GdVO4:Ln3+ (Ln=Eu, Dy, Sm) nanofibers have been prepared by a combination method of sol-gel process and electrospinning technology. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL), quantum efficiency (QE), and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples. The XRD, FT-IR, and TG-DTA results show that GdVO4:Ln3+ nanofibers samples crystallize at 700 °C. SEM images indicate that the as prepared precursor fibers are smooth. After being calcined at 700 °C for 4 h, the fibers still maintain their fiberlike morphology with rough surface. TEM image further manifests that the GdVO4:Ln3+ nanofibers consist of nanoparticles. Under ultraviolet excitation and low-voltage electron beam excitation, GdVO4:Ln3+ phosphors showed their strong characteristic emission due to an efficient energy transfer from vanadate groups to dopants. The optimum doping concentration of Ln3+ in the GdVO4 nanofibers also has been investigated. 相似文献
53.
On the basis of optimized structures of two kinds thiophene oligomers, we investigated the configuration and conformation dependent optical and electronic properties of α or β substituted oligothiophene (PT) and oligo(thienylenevinylene) (PTV) isomers, respectively, at the TD‐DFT/6‐31+G(d,p)//PBE0/6‐31G(d) level. The corresponding properties of polymers were predicted by extrapolation method. The broad absorption regions for polythiophene and/or poly(thienylenevinylene) can be ascribed to the coexistence of various conformational and/or configurational isomers with similar energies and each corresponding excited state possessing different absorption spectrum and overlapping each other. Furthermore, the reorganization energies for electron (λe) and hole (λh) of α or β substituted PTV and PT indicate them to be potential ambipolar charge transport materials under the proper operating conditions. Therefore, these results are important because they can provide a rational way for the design of multifunctional materials with broad absorption and ambipolar charge transport properties for solar cells devices. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
54.
A series of novel spindle-like terphenyl-type chromophores, based on 2,5-diphenyl-1,4-distyrylbenzene π-conjugating bridge, N,N-dimethyl and triphenyl amino donors, and Tricyanovinyldihydrofuran(TCF), 1,3,3-trimethyl-5-dicyanovinyl-1-cyclohexene (TDC) acceptors, have been synthesized successfully for the first time. And the non-linear optical properties were evaluated by using the finite-field (FF) method. The results show that, the first-order hyperpolarizability of the chromophores increase with the increase of the withdraw ability of the substituent group on the π-conjugating bridge. 相似文献
55.
以利用静电纺丝技术制备的TiO2纳米纤维为模板和反应物,原位水热合成了具有异质结构的SrTiO3/TiO2复合纳米纤维.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能量散射光谱(EDS)、高分辨透射电子显微镜( HRTEM)和X射线光电子能谱(XPS)等测试手段对样品的结构和形貌进行了表征.用罗丹明B(RB)模... 相似文献
56.
采用密度泛函理论和含时密度泛函理论方法计算了2个吩噻嗪类染料及其吸附到TiO2上后分子的基态和激发态光物理性质与热力学参数.结果表明,电子给体的改变虽未明显改变染料的光谱性质(垂直跃迁能和振子强度),但可以改变分子的前线轨道能级,进而影响染料分子的激子结合能Eb及激发态电子注入到半导体TiO2中的驱动力△Gint的大小... 相似文献
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TAN HuaQiao CHEN WeiLin LIU Ding YAN AiXue & WANG EnBo Key Laboratory of Polyoxometalate Science of Ministry of Education Northeast Normal University Changchun China 《中国科学B辑(英文版)》2011,(9)
Two new compounds with microporous Co3[MnMo9O32].15H2O(1) and Cu3[MnMo9O32].15H2O(2) have been synthesized,and characterized by IR,element analysis,TG and single-crystal X-ray analysis.The structure analyses reveal that compounds 1 and 2 are isostructural.In crystal,the Waugh-type polyoxoanions [MnMo9O32]6-are connected by Co2+ or Cu2+ cations to a 3D open-framework,which possesses channels along the [1 2 2] direction of approximately 8.27 × 11.97 .The photocatalytic performances of compounds 1 and 2 for p... 相似文献
59.
Non-aggregated spherical polystyrene (PS) particles were coated with GdPO4:Tb3+/Ce3+ phosphor layers by a conventional hydrothermal synthesis using poly(vinylpyrrolidone) (PVP) as an additive without further
annealing treatment. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy
(TEM), photoluminescence (PL), as well as luminescence decay experiments were used to characterise the resulting core-shell
structured PS@GdPO4:Tb3+/Ce3+ samples. The results of XRD indicated that the PS particles were successfully coated with the GdPO4:Tb3+/Ce3+ phosphor layers, which could be further verified by the images of FESEM. Under ultraviolet excitation, the PS@GdPO4:Tb3+/Ce3+ phosphors show Tb3+ characteristic emission, i.e. 5D4-7FJ (J = {6, 5, 4, 3}) emission lines with green emission 5D4-7F5 (543 nm) as the most prominent group. The core-shell phosphors so obtained have potential applications in field emission
display (FED) and plasma display panels (PDP). 相似文献
60.
In this work, gold nanoparticles (AuNPs) were attached to the surface of alumina particles by an in situ immobilizing method. This modified colloidal deposition method allowed the immobilization of AuNPs with a much greater loading amount compared to the conventional one. 相似文献