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991.
MxC60 (M= K、Cs、Rb) 具有的超导性启发人们对C60n- 和C70n- 展开了深入研究。本文综述了富勒烯离子C60n±、C70n±、C76n±、C78n±及C80n±的结构畸变和光谱研究进展,介绍了国内外近十几年来众多研究小组的有关工作,从实验检测到理论计算, 从结构探讨到谱学性质研究, 并结合作者在此方面的理论研究成果,进一步探索富勒烯离子Jahn-Teller 畸变的特点和产生原因以及其电子光谱的规律性。 相似文献
992.
J-T Teng 《The Journal of the Operational Research Society》2008,59(10):1429-1430
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Jeremy J. Intemann Jared F. Mike Min Cai Charles A. Barnes Teng Xiao Robert A. Roggers Joseph Shinar Ruth Shinar Malika Jeffries‐EL 《Journal of polymer science. Part A, Polymer chemistry》2013,51(4):916-923
A series of vinylene‐linked copolymers based on electron‐deficient benzobisthiazole and electron‐rich fluorene moieties were synthesized via Horner–Wadsworth–Emmons polymerization. Three different polymers P1 , P2 , and P3 , were prepared bearing octyl, 3,7‐dimethyloctyl, and 2‐(2‐ethoxy)ethoxyethyl side chains, respectively. The polymers all possessed moderate molecular weights, good solubility in aprotic organic solvents, and high fluorescence quantum efficiencies in dilute solutions. P2 , which bore branched 3,7‐dimethyloctyl side chains, exhibited better solubility than the other polymers, but also exhibited the lowest thermal decomposition temperature of all polymers. Overall, the impact of the side chains on the polymers optical properties in solution was negligible as all three polymers gave similar absorption and emission spectra in both solution and film. Guest‐host light‐emitting diodes using dilute blends of the polymers in a poly(N‐vinylcarbazole) host gave blue‐green emission with P2 exhibiting the highest luminous efficiency, 0.61 Cd/A at ~500 nm. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
994.
Huai‐Long Teng He Huang Prof. Dr. Chun‐Jiang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(40):12614-12618
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Sie Tiong Ha Lay Khoon Ong Siew Ling Lee Hong Cheu Lin Yip Foo Win Siew Teng Ong 《中国化学快报》2010,21(6):637-640
<正>A homologous series of Schiff base esters,4-chlorobenzylidene-4'-n-alkanoyloxyanilines,containing even number of carbons at the end groups of the molecules(C_(n-1)H_(2n-1)COO-,n=4,6,8,10,12,14,16) were synthesized.The mesomorphic properties were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).It was found that the end groups of the molecules had an effect on the mesomorphic properties.n-Butanoyloxy was found non-mesogenic,whilst n-hexanoyloxy exhibited monotropic smectic phase.The higher members in this homologous series were enantiotropic smectogens. 相似文献
996.
Two-dimensional (2-D) metal-organic polymer [Zn3(μ2-4,4′-bipy)2(μ2-be)2(be)2(μ2-N3)2]n 1 (4,4′-bipy = 4,4′-bipyridine, be = benzoate, N3? = azide anion) has been synthesized by low-hot reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV–visible spectra. The 2-D structure is built from the linkage of secondary building units of trinuclear [Zn3(μ2-4,4′-bipy)2(μ2-be)2(be)2(μ2-N3)2] clusters by a mixed connector of 4,4′-bipyridine, benzoate and azide. The third-order non-linear optical (NLO) properties of the 1 were also investigated with modulus of the hyperpolarizability (γ) 8.51 × 10?30 esu for 1 in a 3.17 × 10?4 mol dm?3 DMF solution. 相似文献
997.
In this paper, general nonautonomous discrete-time single-species Kolmogorov model with delays is studied. Some sufficient conditions on the boundedness, persistence, permanence and global attractivity of solutions are established. As application, the discrete time nonautonomous delayed Allee-effect model is discussed. The sufficient conditions on the permanence and global attractivity are obtained. 相似文献
998.
Teng Chi Paul Somers Daniel A. Wilcox Ashley J. Schuman Vasudevan Iyer Ran Le Jamie Gengler Manuel Ferdinandus Carl Liebig Liang Pan Xianfan Xu Bryan W. Boudouris 《Journal of Polymer Science.Polymer Physics》2019,57(21):1462-1475
Printing of high‐resolution three‐dimensional nanostructures utilizing two‐photon polymerization has gained significant attention recently. In particular, isopropyl thioxanthone (ITX) has been implemented as a photoinitiator due to its capability of initiating and depleting polymerization on demand, but new photoinitiating materials are still needed in order to reduce the power requirements for the high‐throughput creation of 3D structures. To address this point, a suite of new thioxanthone‐based photoinitiators were synthesized and characterized. Then two‐photon polymerization was performed using the most promising photoinitiating molecule. Importantly, one of the initiators, 2,7‐bis[(4‐(dimethylamino)phenyl ethynyl)‐9H‐thioxanthen‐9‐one] (BDAPT), showed a fivefold improvement in the writing threshold over the commonly used ITX molecule. To elucidate the fundamental mechanism, the excitation and inhibition behavior of the BDAPT molecule were evaluated using density functional theory (DFT) calculations, low‐temperature phosphorescence spectroscopy, ultra‐fast transient absorption spectroscopy, and the two‐photon Z‐scan spectroscopic technique. The improved polymerization threshold of this new photoinitiator presents a clear pathway for the modification of photoinitiators in 3D nanoprinting. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1462–1475 相似文献
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