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51.
Sang Eok Jang 《Journal of luminescence》2011,131(12):2788-2791
High efficiency single layer blue phosphorescent organic light-emitting diodes (PHOLEDs) without any charge transport layer were developed. A mixed host of spirobifluorene based phosphine oxide (SPPO13) and 1, 1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) was used as the host in the emitting layer. A high maximum external quantum efficiency of 15.8% and a quantum efficiency of 8.6% at 1000 cd/m2 were achieved in the single-layer blue PHOLEDs without any charge transport layer. The maximum power efficiency and power efficiency at 1000 cd/m2 were 31.4 and 16.9 lm/W, respectively. 相似文献
52.
Luminescence efficiency of self-activated CaWO4 under 147 nm vacuum ultraviolet (VUV) radiation excitation is about 90% of that of BaMgAl10O17:Eu2+ (BAM), the commercial blue plasma display panel (PDP) phosphor. However, the color purity and the particle size of the former needs substantial modification before it can be considered for application in PDP. CaWO4:Tm exhibits Tm3+ emission peaks in the blue region due to energy transfer from WO4 to Tm3+ ions but the overall emission intensity under 147 nm excitation is reduced when compared to that of CaWO4. 相似文献
53.
A blue-white emitting Sr2CeO4 phosphor was synthesized via a simple sol-gel poly vinyl alcohol (PVA)-complexing process using strontium nitrate and cerium nitrate as raw materials. The samples were characterized by TG/DTA, XRD, FTIR, SEM and photoluminescence spectroscopy. The X-ray diffraction study confirms the structure of the system to be orthorhombic. The emission spectra when excited at 267 nm peaks at ∼470 nm. The emission band is assigned to the energy transfer between the molecular orbital of the ligand and charge transfer state of the Ce4+ ion. The Commission International de l'Eclairage (CIE) co-ordinates for the Sr2CeO4 sample were also calculated. 相似文献
54.
Guangming Chen Jingjun Pan Busing Han Haike Yan 《Journal of Dispersion Science and Technology》2013,34(4):1179-1187
ABSTRACT Adsorption of Methylene Blue ( MB) on Na-, Fe- and Al-montmorillonite suspensions at 298.15 K were studied. The effect of different exchangeable cation on the adsorption amount of MB was determined. The results show that methylene blue cations( MB+ ) replace Na? more easily than they do Fe3+ and Al3 + The adsorption isotherms on the three montraorillonites were all of Langmuir type, except that the isouHerm of MB on Na-montmorillonite presents nonmonotonic curve at low surface coverage. The specific surface areas in suspension were calculated by( MB 3 + )method, and Na? is more effective to determine the specific surface area by MB method in suspension than Fe3 + and A3 + The discrepancy of the specific surface area measured by MB and BET method was discussed. 相似文献
55.
Kazunari Ozasa Shigeyuki Nemoto Mizuo Maeda Masahiko Hara 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):89
We have found that the photoluminescence (PL) intensity of CdSe/ZnS nanocrystals placed on a thin film of insulator (GaAsOx/GaAs) depends on excitation wavelength through the interference effects of the excitation light. By employing the multi-reflection/interference calculation, the insulator thickness of the underlying non-uniform patterns can be evaluated by the simple observation of CdSe/ZnS PL with a couple of excitation wavelengths. Moreover, the differences observed for the temporal evolution of CdSe/ZnS PL (blue shifts and degradation) among the excitation wavelengths suggest that the photo-induced changes of chemical composition and surface ligands are responsible for blue shifts and degradation, respectively. 相似文献
56.
本文研究了用新生MnO2作吸剂,对水中直接耐晒蓝(B2RL)染料进行脱色的特性,探讨了影响吸附的因素,并给出适宜的吸附条件,在本试验条件下可使B2RL脱色主达95%。 相似文献
57.
石墨炉原子吸收光谱法间接测量尿样中氨基多糖含量 总被引:2,自引:0,他引:2
本文采用阿利新蓝(AlcianBlue)与尿样中氨基多糖(以下称GAG)在pH=5.8的醋酸钠溶液中,发生沉淀反应生成GAG铜复合物。离心分离沉淀物,以石墨炉原子吸收光谱测定沉淀物中铜含量,间接计算GAG含量。本文对尿样加入染液浓度,沉淀反应平衡时间;沉淀物的洗涤剂、洗涤次数等进行了探讨,确定了最佳实验条件,实测了60例健康人尿中GAG含量,与文献报导值一致。 相似文献
58.
A direct extractive method has been developed for preparation of pure Semi-Methylthymol Blue (SMTB) from a synthetic mixture containing ca. 30% of SMTB in presence of Thymol Blue (TB, ca. 45%), Methylthymol Blue (MTB, ca. 10%) and other components such as acetic acid and iminodiacetic acid (IDA). The method is based on the dependence of the extraction coefficients of the individual components on the pH of an aqueous phase in equilibrium with butanol phase. The separation of TB from the mixture is best at pH 9.5–10.5 and the separation of SMTB is best at pH 2.9–4.5. At pH 10.2 the ratio of the extraction coefficient of TB to that of SMTB is 213 and to that of MTB is 776. At pH 2.9 the ratio of the extraction coefficient of SMTB to that of MTB is ca. 20 and at pH 4.5 is ca. 100, but the absolute values of the extraction coefficient for SMTB are only 3.4 at pH 4.5 and ca. 10 at pH 2.9. This means the quantitative transfer of SMTB to the butanol phase is much easier at pH 2.9. Then a more complete separation of SMTB from the mixture with MTB can be achieved by stripping of the latter into a pH 4.5 aqueous medium. The method for obtaining of anhydrous SMTB is also given. About 70% of the original amount SMTB present can be obtained as the dry product (containing over 99% SMTB). 相似文献
59.
Franck Charmantray Nadia Touisni Laurence Hecquet Thierry Noguer Christine Mousty 《Electroanalysis》2015,27(6):1341-1344
This paper describes the development of an amperometric biosensor based on galactose oxidase (GAOx) immobilization within a laponite clay film deposited on Carbon Screen‐Printed Electrodes modified by electrodeposited Prussian Blue and coated with poly‐(O‐phenylenediamine) (PPD/PB/CSPEs). Amperometric performances of GAOx@laponite/PPD/PB/CSPEs bioelectrodes were determined using several GAOx substrates. Using these modified electrodes the reduction of enzymatically generated hydrogen peroxide was performed at ?0.2 V vs. Ag‐AgCl. In an initial attempt, E.Coli transketolase activity on its immobilized form was followed using a bienzymatic GAOx‐TK biosensor. 相似文献
60.
Yu-Qiao GUAN Gang CHEN Juan SONG Cheng-Xin WANG Yan QIAN Qin ZHANG Ling-Ling DENG Zeng-Qin FENG Wen-Juan SHANG You-Tian TAO Shu-Fen CHEN Lian-Hui WANG Wei HUANG 《物理化学学报》2017,33(4):816-822
We synthesized a series of novel spiro[fluorene-9, 9'-xanthene] (SFX)-based host materials via a one-step palladium-catalyzed cross-coupling reaction. These materials have high triple energy levels and high yield, and thus can be used as hosts for blue phosphors. Blue phosphorescent organic light-emitting devices (PHOLEDs) with a bis (3, 5-difluoro-2-(2-pyridyl) phenyl-(2-carboxypyri-dyl) iridium (Ⅲ) (FIrpic) emission were fabricated. Furthermore, we applied cohosts composed of one of the new synthesized materials and the hole transport material di-[4-(N, N-ditolyl-amino)-phenyl]cyclohexane (TAPC) to the blue PHOLEDs to successfully acquire efficient blue emissions. The SFX-based material provided efficient energy transfer while TAPC improved the mobility of the cohost as well as reduced the working voltage. Maximum current efficiencies of 22.56 and 25.93 cd·A-1 and the maximum brightnesses of 6421 and 6196 cd·m-2 were obtained for the PHOLEDs with TAPC: 2-(9-phenyl-fluoren-9-yl) spiro[fluorene-9, 9'-xanthene] (PF-SFX) and TAPC: 2-(9-(4-(octyloxy)-phenyl)-9H-fluoren-9-yl) spiro[fluorene-9, 9'-xanthene] (C8OPF-SFX) cohosts, respectively. The experimental results obtained for the four SFX-based host materials were enough to declare that SFX is an effective main unit that can be used to build efficient host materials for blue phosphors containing only C, H, and O basic elements. 相似文献