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71.
H.‐C. Su F.‐C. Fang T.‐Y. Hwu H.‐H. Hsieh H.‐F. Chen G.‐H. Lee S.‐M. Peng K.‐T. Wong C.‐C. Wu 《Advanced functional materials》2007,17(6):1019-1027
Highly efficient orange and green emission from single‐layered solid‐state light‐emitting electrochemical cells based on cationic transition‐metal complexes [Ir(ppy)2sb]PF6 and [Ir(dFppy)2sb]PF6 (where ppy is 2‐phenylpyridine, dFppy is 2‐(2,4‐difluorophenyl)pyridine, and sb is 4,5‐diaza‐9,9′‐spirobifluorene) is reported. Photoluminescence measurements show highly retained quantum yields for [Ir(ppy)2sb]PF6 and [Ir(dFppy)2 sb]PF6 in neat films (compared with quantum yields of these complexes dispersed in m‐bis(N‐carbazolyl)benzene films). The spiroconfigured sb ligands effectively enhance the steric hindrance of the complexes and reduce the self‐quenching effect. The devices that use single‐layered neat films of [Ir(ppy)2sb]PF6 and [Ir(dFppy)2sb]PF6 achieve high peak external quantum efficiencies and power efficiencies of 7.1 % and 22.6 lm W–1) at 2.5 V, and 7.1 % and 26.2 lm W–1 at 2.8 V, respectively. These efficiencies are among the highest reported for solid‐state light‐emitting electrochemical cells, and indicate that cationic transition‐metal complexes containing ligands with good steric hindrance are excellent candidates for highly efficient solid‐state electrochemical cells. 相似文献
72.
A. Vahid Shahidi I. Shih T. Araki C. H. Champness 《Journal of Electronic Materials》1985,14(3):297-310
Structural investigation on monocrystalline CuInSe2 samples has been made. From the single crystal results, the space group of CuInSe2 was confirmed to be Iˉ42d and the crystal solidification direction was investigated. Compositional uniformity of the ingots
was established by EPMA and it was found that the indium concentration was greater than that for copper. Systematic annealing
experiments were carried out in vacuum at different temperatures (as low as 160° C) and for different times. Large variation
in resistivity was observed after the annealing treatment. P-type samples were found to convert to n-type after the heat-treatments. 相似文献
73.
A novel finger‐sensing nanocomposite with remarkable and reversible piezoresistivity is successfully fabricated by dispersing homogeneously conductive graphite nanosheets (GNs) in a silicone rubber (SR) matrix. Because of the high aspect ratio of the graphite nanosheets, the nanocomposite displays a very low percolation threshold. The SR/GN nanocomposite with a volume fraction of conductive nanosheets closest to that for the percolation threshold presents a sharp positive‐pressure coefficient effect of the resistivity under very low pressure, namely, in the finger‐pressure range (0.3–0.7 MPa), whereby the abrupt transition could be attributed to compressive‐stress‐induced deformation of the conducting network. The super‐sensitive piezoresistive behavior of the nanocomposite is accounted for by an extension of the tunneling conduction theory which provides a good approximation to the piezoresistive effect. 相似文献
74.
研究了某种环氧树脂阻尼灌封胶在热氧老化的作用下分子结构、硬度、断面形貌以及动态力学性能随时间的变化.傅立叶红外光谱图表明,所制备的样品环氧基团反应比较完全,热氧老化后试样表面由仲胺和环氧基团形成的酯键发生了部分断裂和氧化;邵氏硬度的增加、瓦向高温区移动则表明在老化过程中复杂的固化反应仍然继续进行;最大损耗因子(tanδmax)波动较小表明试样老化后分子结构几乎保持不变;SEM图片显示试样的冲击断裂由老化前的韧性转变为老化后的脆性断裂. 相似文献
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77.
介绍煤炭码头带式输送机联锁控制系统设计的一种方法,详细阐述了整个系统的工艺流程、启动方式以及控制原理等。这种方法可以实现带式输送机远程中控室控制,也可进行就地带式输送机机侧控制。 相似文献
78.
Preparation and Properties of Rare Earth Modified Carbon Black/Natural Rubber Composites 总被引:2,自引:2,他引:0
Lin Yaling Xiao Kongqing Zhang Anqiang Wang Lianshi 《中国稀土学报(英文版)》2005,23(6):720-720
The oxides Eu, Ho, Er and Dy were used to prepare the hydroxides of rare earth modified carbon black. Then natural rubber latex (NRL) was added into the reactor. The system reacted at 85 ℃ with stirring for 1 h to prepare powdered HAF-Ln(OH)3/NR composites. The effects of the kind and content of Ln on the particle size distribution of P [ NR/HAF-Ln (OH)3 ] and mechanical properties of its vulcanizate were studied respectively. It is found that rare earth can help to get the powder of the composite, the product particle with a diameter less than 0.9mm will be get when the composites containing the compound of Ho, Er and Dy with dosage of 1.0, 1.0, O. 5 percent, respectively. The adding of Ln can improve the tensile strength and tear strength of the vulcanizate effectively, what's more, Er and Dy can decrease the permanent set of vulcanizate significantly. The SEM studies shows that P[ NR/HAF-Dy (OH)3 ] vulcanizate shows superior mechanical properties that depend primarily on the absence of free carbon black, the fine dispersion of carbon black in the rubber matrix and better polymer-filler interaction. 相似文献
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