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11.
Hydrophobic, methyl-terminated self-assembled monolayer (SAM) surfaces can be used to reduce friction. Among methyl-terminated SAMs, the frictional properties of alkanethiol SAMs and silane SAMs have been well-studied. In this research, we investigated friction of methyl-terminated n-hexatriacontane (C36) SAM and compared its friction properties with the alkanethiol and silane SAMs. Alkane SAM does not have an anchoring group. The alkane molecules stand on the surface by physical adsorption, which leads to a higher surface mobility of alkane molecules. We found that C36 SAM has a higher coefficient of friction than that of octadecyltrichlorosilane (OTS) silane. When an atomic force microscope (AFM) tip was swiped across the alkane SAM with a loading force, we found that the alkane SAM can withstand the tip loading pressure up to 0.48 GPa. Between 0.48 and 0.49Ga, the AFM tip partially penetrated the SAM. When the tip moved away, the deformed SAM healed and maintained the structural integrity. When the loading pressure was higher than 0.49 GPa, the alkane SAM was shaved into small pieces by the tip. In addition, we found that the molecular tilting of C36 molecules interacted with the tribological properties of the alkane SAM surface. On one hand, a higher loading force can push the rod-like alkane molecules to a higher tilting angle; on the other hand, a higher molecular tilting leads to a lower friction surface. 相似文献
12.
Yue Shen Xiaohui Tang Yuwei Xu Haichao Liu Shitong Zhang Bing Yang Yuguang Ma 《中国化学快报》1990,30(11):1947-1950
Cyanophenyl as ancillary acceptor to modify donor-acceptor compound,plays an effective role in shifting the emission color to deep red and maintaining the luminescent efficiency. 相似文献
13.
In this paper, using the idea of Bartnik [B2] on quasi-spherical metrics we continue our study on the boundary behaviors of compact manifolds with nonnegative scalar curvature and nonempty boundary. Unlike the previous work [ST] of the authors and the work of Liu-Yau [LY], we only assume each boundary component has nonnegative curvature which is not identically zero. We also study the case that the boundary is embedded in the quotient of the infinity of the Euclidean space over a finite group. The regularity of the black hole boundary condition of quasi-spherical metrics is also discussed.Research partially supported by NSF of China, Projects 10001001 and 10231010.Research partially supported by Earmarked Grant of Hong Kong #CUHK4032/02P. 相似文献
14.
Gang?ChengEmail author Yi?Zhao Jingying?Hou Yu?Duan Yuguang?Ma Shiyong?Liu 《Optical and Quantum Electronics》2004,36(14):1193-1203
In view of their potential applications in flat panel displays, organic light-emitting devices have attracted much attention in the past decade. A challenging target in this field is to realize full color display applications. One of the approaches proposed for these is combining white emission with color filters, where efficient and pure white emission (especially at high brightness) is necessary. In this paper, three kinds of white organic light-emitting devices with different structures and materials are fabricated and their characteristics are discussed. 相似文献
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16.
Hu D Shen F Liu H Lu P Lv Y Liu D Ma Y 《Chemical communications (Cambridge, England)》2012,48(24):3015-3017
An electrical and optical energy gaps separation strategy is put forward for the design of organic wide bandgap semiconductors. This new principle could achieve optimization of wide bandgap (both high singlet and triplet energies) and favorable carrier injection energy levels simultaneously. 相似文献
17.
18.
Teng Fei Gang Cheng Dehua Hu Ping Lu Yuguang Ma 《Journal of polymer science. Part A, Polymer chemistry》2009,47(18):4784-4792
We have synthesized a novel wide band gap polymer P36HCTPSi derived from 3,6‐carbazole and tetraphenylsilane by palladium‐catalyzed Suzuki coupling reaction. The resultant polymer shows a high glass transition temperature (217 °C) and good thermal stability. The conjugation length of P36HCTPSi is effectively confined because of the δ‐Si interrupted polymer backbone. The polymer exhibits a violet emission with a peak at 392 nm in solution, and the band gap estimated from the onset of its absorption is 3.26 eV. The high energy emission and wide band gap of P36HCTPSi make it appropriate host for green and blue emission phosphorescent materials. Efficient energy transfers from P36HCTPSi to both fac‐tris[2‐(2‐pyridyl‐kN)‐5‐methylphenyl]iridium(III) (green emission) and bis[(4,6‐difluorophenyl)pyridinato‐N,C2]‐(picolinato)iridium(III) (blue emission) were observed in photoluminescence (PL) spectra. Highly efficient phosphorescent polymer light‐emitting devices were realized by using P36HCTPSi as the host for iridium complexes, the maximum luminous efficiencies for green and blue devices were 27.6 and 3.4 cd/A, respectively. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4784–4792, 2009 相似文献
19.
Yali Fu Jingchang Zhang Zhong Huang Xiuyu Wang Yuguang Lv Weiliang Cao 《Journal of photochemistry and photobiology. A, Chemistry》2008,197(2-3):329-334
Four ternary complexes of Tb(III) were synthesized by introducing the first ligand (L1) (N-phenylanthranilic acid (N-HPA), α-furoic acid (FURA)) and the second ligand (L2) (1,10-phenanthroline (Phen), 2,2′-dipyridyl (Bipy)), respectively. These complexes were characterized by elemental analysis, infrared spectra, XRD, UV spectra and fluorescence spectra. The effect of L1 and L2 on the fluorescence properties of terbium complexes was discussed. It showed that all the complexes exhibited ligand-sensitized green emission. The fluorescent intensity increased in the sequence of Tb(FURA)3Bipy < Tb(N-PA)3Phen < Tb(FURA)3Phen < Tb(N-PA)3Bipy. It indicated that L1 affected fluorescence properties of the complexes differently when the corresponding L2 altered. Meanwhile, the influence of L2 on the luminescence properties of the complexes also depends on L1. The results showed that L1 and L2 affected each other and worked together as a whole. The matching of L1, L2 and Tb3+ ion is very important to the luminescence properties of Tb(III) ternary complexes. 相似文献
20.
Xu Yuguang Cheng Kefan Liu Tianhua Zhu Hongfeng 《International Journal of Theoretical Physics》2021,60(11-12):4196-4209
International Journal of Theoretical Physics - How to apply E-payment based on quantum cryptography to our daily life is a significant problem. Inspired by the semi-quantum protocols, we present a... 相似文献