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61.
The relationship between sequence distributions and molecular weight distributions of S-SBR, obtained from styrene and butadiene anionic copolymerization at various conversions with THF/Li~+ as an initiator has been studied by ~(13)C-NMR,GPC. The results showed that the molecular weight distributions of the copolymer couldbe correlated sophisticatedly to the binary sequcne distributions or the monomer unit distributions of the copolymer in a corrected Poisson's distribution from. 相似文献
62.
A new nonlinear optical organic crystal l-tryptophan p-nitrophenol (LTPNP) of dimension 19 mm × 2 mm × 1.5 mm has been grown from an aqueous solution for the first time by slow evaporation technique at ambient temperature. The crystal structure of LTPNP was confirmed by single crystal X-ray diffraction. LTPNP crystallizes in non-centrosymmetric monoclinic system with space group P21. The recorded FTIR spectrum confirms the presence of various functional groups in the grown crystal and confirms the formation of LTPNP. Thermal stability and melting temperature of the LTPNP crystal were identified from TG/DTA analysis. The optical absorption study confirms the suitability of the crystal for device applications. LTPNP exhibits SHG efficiency over 1.7 orders of magnitude higher than that of urea and 4 orders of magnitude higher than that of KDP. 相似文献
63.
V. S. Kushawaha 《光谱学快报》2013,46(10):633-645
An extensive calculation was carried out using the precisely measured value of the Q-band heads and the following molecular constants for the C2π1 2 and the X2σ states, which are responsible for the Green Band System of BaF, were determined. 相似文献
64.
Bound rubber formation was investigated in detail by applying various extraction temperatures (at room temperature, 90°C, and 180°C) and novel treatment methods (ammonia bubbling and sonication). Bound rubbers could be divided into three major components of core shell, primary layer including tightly primary layer and occluded rubber, and secondary layer including connecting filament. Bound rubber content of the core shell was measured by four successive procedures of extraction at room temperature, ammonia bubbling, extraction at 180°C and sonication. Bound rubber content of the tightly primary layer was measured by three successive procedures of extraction at 90°C, ammonia bubbling and sonication. Bound rubber content of the primary layer was measured by two successive procedures of extraction at 90°C and sonication. 相似文献
65.
This note gives necessary and sufficient conditions for exponential stability of semigroups of linear operators in Banach spaces. Generalizations of a well-known result due to Datko, Pazy and Neerven are obtained for the case of semigroups of operators that are not strongly continuous. 相似文献
66.
《Optimization》2012,61(4):293-316
The paper develops sufficient conditions for controllability and necessary conditions in different forms of the maximum principle for extremal solutions of discrete inclusions. The objective function is assumed to be locally lipschitzian only 相似文献
67.
《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2107-2110
Alcohols were oxidized to their corresponding carbonyl compounds with KBrO 3 in the presence of silica chloride and wet SiO 2 , in solution and under solvent free conditions. 相似文献
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A series of novel solution-processable small-molecule host materials: 2DPF-TCz, 2SBF-TCz, 27DPF-TCz, and 27SBF-TCz comprising a fluorene monomer as the rigid core and tri-carbazole as the periphery have been designed and synthesized, and their optical, electrochemical, and thermal properties have been fully characterized. The host materials exhibit high glass-transition temperatures (231–310 °C) and high triplet energy levels (2.61–2.73 eV). High-quality amorphous thin films can be obtained by spin-coating the host materials from solutions. It is found that the HOMO level of the host materials can be tuned by linking the tri-carbazole unit to the 2,7 positions of the fluorine core, resulting in appropriate HOMO energy levels (−5.36 to −5.23 eV) for improved hole-injection in the device. Solution-processed blue and green electrophosphorescent devices bases on the developed host materials exhibit high efficiencies of 21.2 and 34.8 cd A−1, respectively. 相似文献