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121.
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Mui Siang Soh Sonsoles Amor Garcia Santamaria Evan Laurence Williams Marta Pérez‐Morales Henk J. Bolink Alan Sellinger 《Journal of Polymer Science.Polymer Physics》2011,49(7):531-539
A new class of solution processable dendrimers based on cyclic phosphazene (CP) cores have been prepared and used as host materials for blue and green organic light emitting diodes (OLEDs). The dendrimers are prepared in high yield from minimal step reactions, are soluble in common solvents for solution processing, are amorphous, and have excellent thermal properties necessary for application in OLEDs. OLED efficiencies of 10.3 cd/A (4.2 lm/W) and 35.3 cd/A (33.5 lm/W) were achieved using commercially available FIrpic and Ir(mppy)3 as blue and green phosphorescent emitters, respectively. These efficiencies were 2× higher than control devices prepared using poly(N‐vinylcarbazole), the most commonly used host material in solution processed phosphorescent OLEDs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
123.
Xiao‐Hua Ma Li‐Min Fu Yunfeng Zhao Xi‐Cheng Ai Jian‐Ping Zhang Yu Han Zhi‐Xin Guo 《Journal of Polymer Science.Polymer Physics》2011,49(9):649-656
Achiral nonlinear optical (NLO) chromophores 1,3‐diazaazulene derivatives, 2‐(4′‐aminophenyl)‐6‐nitro‐1,3‐diazaazulene (APNA) and 2‐(4′‐N,N‐diphenylaminophenyl)‐6‐nitro‐1,3‐diazaazulene (DPAPNA), were synthesized with high yield. Despite the moderate static first hyperpolarizabilities (β0) for both APNA [(136 ± 5) × 10?30 esu] and DPAPNA [(263 ± 20) × 10?30 esu], only APNA crystal shows a powder efficiency of second harmonic generation (SHG) of 23 times that of urea. It is shown that the APNA crystallization driven cooperatively by the strong H‐bonding network and the dipolar electrostatic interactions falls into the noncentrosymmetric P212121 space group, and that the helical supramolecular assembly is solely responsible for the efficient SHG response. To the contrary, the DPAPNA crystal with centrosymmetric P‐1 space group is packed with antiparalleling dimmers, and is therefore completely SHG‐inactive. 1,3‐Diazaazulene derivatives are suggested to be potent building blocks for SHG‐active chiral crystals, which are advantageous in high thermal stability, excellent near‐infrared transparency and high degree of designing flexibility. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
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The expansion coefficient CD|L| of Coulomb potential 1/r12 of atomic system in hyper‐spherical harmonics is derived and the explicit expression is given. 相似文献
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Significant progress has been made in understanding the nature of the transition state andthe paths for electron transfer, especially the influences of environmental factors and themolecular properties on the electron transfer rate. These classical and semi-classical, aswell as quantum-mechanical theory, have been very successful in rationalizing severalstructure-reactivity relationships and in predicting novel features of reactivity. Thesemodels established some links between the electron tra… 相似文献
128.
H. Ai Y.-L. Song F.-G. Tao 《Acta Crystallographica. Section C, Structural Chemistry》1999,55(1):IUC9800080-IUC9800080
129.
XuHai Yang ZhiGang Li ChuGang Feng Ji Guo HuLi Shi GuoXiang Ai FengLei Wu RongChuan Qiao 《中国科学G辑(英文版)》2009,52(3):333-338
A geostationary (GEO) satellite may serve as a navigation satellite, but there is a problem that maneuvers frequently occur
and the forces are difficult to model. Based on the technique of determining satellite orbits by transfer, a predicted orbit
with high accuracy may be achieved by the method of statistical orbit determination in case of no maneuver force. The predicted
orbit will soon be invalid after the maneuver starts, and it takes a long time to get a valid orbit after the maneuver ends.
In order to improve ephemeris usability, the method of rapid orbit forecasting after maneuvers is studied. First, GEO satellite
movement is analyzed in case of maneuvers based on the observation from the orbit measurement system by transfer. Then when
a GEO satellite is in the free status just after maneuvers, the short arc observation is used to forecast the orbit. It is
assumed that the common system bias and biases of each station are constant, which can be obtained from orbit determination
with long arc observations. In this way, only 6 orbit elements would be solved by the method of statistical orbit determination,
and the ephemeris with high accuracy may be soon obtained. Actual orbit forecasting with short arc observation for SINOSAT-1
satellite shows that, with the tracking network available, the precision of the predicted orbit (RMS of O-C) can reach about
5 m with 15 min arc observation, and about 3 m with 30 min arc observation.
Supported by the National High Technology Research and Development Program of China (Grant No. 2006AA12Z322), the National
Basic Research Program of China (Grant No. 2007CB815503), and the West Light Program of Chinese Academy of Sciences (Grant
No. 2007LH01) 相似文献
130.