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71.
72.
一种新型稀土有机电致发光材料:Eu(NO3)3phen 总被引:3,自引:0,他引:3
稀土离子的窄谱带发射能够很好地满足彩色显示的要求,寻找新的具有更高荧光量子效率的稀土有机材料作为发光层,以做出更高发光亮度的有机电致发光器件是非常有意义的。 相似文献
73.
Fan S Sun M Chen Z Luo J Hou Q Peng J Yang H Zhang D Li F Cao Y 《The journal of physical chemistry. B》2007,111(22):6113-6117
The small molecule 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DBT) dye has been synthesized and blended into blue-emitting polyfluorene as a host. The photophysics of the blend films and electroluminescence device performance was compared with that from polyfluorene-co-4,7-di-2-thienyl-2,1,3-benzothiadiazole (PFO-DBT) copolymer of the same molar composition, with DBT incorporated covalently into the polyfluorene backbone. The role of intra- and interpolymer chain interaction and energy transfer in the polymer light-emitting devices are discussed. On the basis of the direct comparison of blend and copolymer from the same molecular composition, we can draw the conclusion that, in conjugated polymers, intrachain energy transfer along the polymer backbone is more efficient than that via interchain interaction and plays a more important role in polymer light-emitting devices. 相似文献
74.
合成了一种新的含异马来二氰基二硫烯(i-mnt)镍(Ⅱ)配阴离子的2-萘亚甲基哌啶([2-NaMePid]+)盐(简记为[2-NaMePid]2[Ni(i-mnt)2]).基于元素分析、摩尔电导测定,以及红外光谱、紫外-可见光谱、X射线单晶衍射分析确定了其组成和结构.结果显示,合成的哌啶盐属于三斜晶系,P-1空间群,分子中的[Ni(imnt)2]2-阴离子通过短程的C…N作用形成一维链;阴、阳离子之间的静电作用,以及N-H…N和C-H…Ni氢键促进分子的堆积和稳定. 相似文献
75.
76.
Benzylation of phenol was successfully achieved in water under room temperature mediated by tetrabutylammonium bromide (TBAB) for only 2 h affording the corresponding benzyl phenyl ether with good to excellent yields. This protocol is very efficient, simple, avoiding catalysts, easy to work-up after reaction, and especially ‘green’. 相似文献
77.
Treatment of cis-1,4-diaryl-2,3-epoxy butane with 2,3-dichloro-5,6-dicyano-1,4-benzo-quinone(DDQ) in trifluoroacetic acid(TFA) gave dibenzocycloheptadienes by pinacol rearrangement and intramolecular oxidative coupling of the aryl groups. Meanwhile, the benzofuran analogues were also formed by the same method. These new lignans have potent CNS inhibitory activities. It has been proven that the method is particularly useful when applied to the substrates in which the ring substituents are electron donating. The structures of these products were identified by the MS, UV, IR, NMR spectra, and elemental and X-ray crystallographic analyses. 相似文献
78.
Baiquan Liu Miao Xu Lei Wang Hong Tao Yueju Su Dongyu Gao Linfeng Lan Jianhua Zou Junbiao Peng 《固体物理学:研究快报》2014,8(8):719-723
A high‐performance hybrid white organic light‐emitting diode (WOLED) based on a simple structure has been developed. The resulting device exhibits a maximum total current efficiency and power efficiency of 35.7 cd/A and 30.6 lm/W, respectively. Even at a high luminance of 1000 cd/m2, a current efficiency of 32.0 cd/A and a power efficiency of 19.4 lm/W are obtained, suggesting that the device exhibits a low efficiency roll‐off. Besides, the device shows excellent color‐stability during a wide range of luminance and a high color rendering index (CRI) of 83 is obtained. Moreover, the origin of the superior properties is explored comprehensively. Such achieved results demonstrate that high efficiency, low efficiency roll‐off, stable color and high CRI can be simultaneously realized in a simplified hybrid WOLEDs. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
79.
Junbiao Zhu Zhijiang Wang Jiejia Zhuang 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1996,24(5):1285-1290
Various mechanisms of electron emission, including the field, field-enhanced thermionic, and explosive electron emissions from pseudospark cathodes, are discussed and compared. The mechanism of the field-induced explosive electron emission due to microstructure on the cathode surface is considered to be more likely the pseudospark superemissive mechanism. A high-mean electric field up to 3-5 MV/cm on the cathode surface in the end of hollow cathode phase is enough to initiate the mechanism. The cathode spot initiation delay time (<10 ns) and explosive emission threshold current (~108 A/cm2 ) prior to the high current conducting phase are given by solving the initial value problem of the one-dimensional heat conduction equation, thus explaining the existing experimental data of the pseudospark cathode superemission. In the case of multigap discharge, the above mechanism occurs on nearly all cathode and interelectrode surfaces. Experimental evidence in single- and multigap pseudospark discharges supports the suggested explanation 相似文献
80.
Naiying Du Renyu Tian Junbiao Peng Mangeng Lu 《Journal of polymer science. Part A, Polymer chemistry》2005,43(2):397-406
A series of novel metaloquinolate [aluminum quinolate (Alq3), zinc quinolate (Znq2), and lithium quinolate (Liq)]‐containing copolymers were prepared. This is the first report of the synthesis of metaloquinolate‐containing polymers by free‐radical copolymerization. The structures of the metaloquinolate monomers and copolymers were characterized by 1H NMR and Fourier transform infrared techniques. The differential scanning calorimetry and thermogravimetric analysis results showed that the copolymers were more thermally stable than the methyl methacrylate homopolymer. The copolymers (<25 wt % Alq3, <20 wt % Znq2, or <15 wt % Liq) could be dissolved in common solvents without crosslinking. The ultraviolet–visible absorption and photoluminescence (PL) emission properties of the copolymers were consistent with the literature data of metaloquinolate complexes. The PL efficiencies of the metaloquinolate‐containing copolymers with 25 wt % Alq3, 20 wt % Znq2, or 15 wt % Liq were 19.89, 13.24, and 11.82%, respectively. The experimental results indicated that these kinds of materials could be used for practical applications in organic light‐emitting diodes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 397–406, 2005 相似文献