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311.
A novel oligothiophene derivative containing the triphenylamine moiety with high glass transition temperature (Tg; 135 °C), 5,5′‐{bis[4‐di(4‐thiophenyl)amino]phenyl}‐2,2′‐bithiophene (TTPA‐dimer) was synthesized by the dimerization of tris[4‐(2‐thienyl)phenyl]amine (TTPA) with a palladium catalysis. Some types of electroluminescent (EL) devices that use the amorphous material for a hole‐ and an electron‐transporting with an emitting layer were fabricated. These devices emitted a bright green‐yellowish light (λemi; around 510 nm) with a small full width at half maximum (FWHM) rather than that of Alq3. The single layer EL device showed a maximum luminance of 221 cd/m2 at 8 V (0.06 lm/W at 100 cd/m2). On the other hand, the double layer (TTPA‐dimer/Alq3) EL device that used Alq3 as the electron transport material was increased up to 10830 cd/m2 at 12 V (0.89 lm/W at 300 cd/m2) and with a lower turn‐on voltage (3.2 V at 0.1 cd/m2) than other types of EL devices. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
312.
Qingde Zhang Yisheng Tan Caihong Yang Yizhuo Han Jun Shamoto Noritatsu Tsubaki 《天然气化学杂志》2007,16(3):322-325
The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40(40%)/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modification of H3PW12O40(40%)/SiO2 gave the most promising result of 20% dimethyl ether conversion and 34.8% dimethoxymethane selectivity. Dimethoxymethane could be synthe- sized via methoxy groups decomposed from dimethyl ether through the synergistic effect between the acid sites and the redox sites of Cs modified H3PW12O40(40%)/SiO2. 相似文献
313.
报道了一种单颗粒微电极制备新方法, 并研究了LaNi4.7Al0.3球形单颗粒微电极的电化学行为. 相似文献
314.
315.
Metz AW Ireland JR Zheng JG Lobo RP Yang Y Ni J Stern CL Dravid VP Bontemps N Kannewurf CR Poeppelmeier KR Marks TJ 《Journal of the American Chemical Society》2004,126(27):8477-8492
A series of low-melting, thermally stable cadmium metal-organic chemical vapor deposition (MOCVD) precursors have been synthesized, structurally and spectroscopically characterized, and implemented in growth of highly conductive and transparent CdO thin films. One member of the series, bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)(N,N-diethyl-N',N'-dimethyl-ethylenediamine)cadmium(II), Cd(hfa)(2)()(N,N-DE-N',N'-DMEDA), represents a particularly significant improvement over previously available Cd precursors, owing to the low melting point and robust thermal stability. High-quality CdO films were grown by MOCVD on glass and single-crystal MgO(100) between 300 and 412 degrees C. Film growth parameters and substrate surface have large effects on microstructure and electron carrier transport properties. Enhanced mobilities observed for highly biaxially textured films grown on MgO(100) vs glass are attributed, on the basis of DC charge transport and microstructure analysis, to a reduction in neutral impurity scattering and/or to a more densely packed grain microstructure. Although single-grained films grown on MgO(100) exhibit greater mobilities than analogues with discrete approximately 100 nm grains and similar texture, this effect is attributed, on the basis of charge transport and Hall effect measurements as well as optical reflectivity analysis, to differences in carrier concentration rather than to reduced grain boundary scattering. Unprecedented conductivities and mobilities as high as 11,000 S/cm and 307 cm(2)/V.s, respectively, are obtained for epitaxial single-grained films (X-ray diffraction parameters: fwhm(omega) = 0.30 degrees, fwhm(phi) = 0.27 degrees ) grown in situ on MgO(100) at a relatively low temperature (400 degrees C). 相似文献
316.
TheBeckInannrearrangement,theacid-mediatedisomerizationofoximestoamides,wasfirstdiscoveredinl886l.Asoneoftheoldestandmostfamiliartransformationsinorganicchemistry,ithasbeenwidelystudiedandagreatvarietyofmethodstoconductthistfansformationhavebeenreported'.However,mostofthesemethodswerecarriedoutbyusingalargeamountofsolventswithlongreactiontime.Whatismore,thepriorpreparationofthecorrespondingketoximesisusuallyrequired,whichmakestheseprocessesinconvenientandlessattractive.Bytakingadvantageofboth… 相似文献
317.
流动注射化学发光抑制法测定维生素E 总被引:4,自引:0,他引:4
实验发现,H2SO4-KMnO4-甲醛在丙酮存在下发光信号大大增强,据此建立了H2SO4-KMnO4-甲醛-丙酮新体系。同时发现维生素E(VE)对H2SO4-KMnO4-甲醛-丙酮化学发光体系有强烈的抑制作用,建立了维生素E的流动注射化学发光抑制法的新体系。化学发光信号的降低值与VE的浓度在1.0×10-5~1.0×10-3mol/L的范围内呈良好的线性关系,方法的检出限为3.0×10-6mol/L。对1.0×10-4mol/L的VE进行11次平行测定,其相对标准偏差为1.5%。该法已用于VE片剂中VE的测定。 相似文献
318.
马来酸酐与聚烯烃接枝产物的表征 总被引:21,自引:1,他引:21
综述了马来酸酐与聚烯烃接枝产物的多种表征手段,重点分析了纯化处理,化学滴定以及红外分析方法的表征原理,应用和改进方法。 相似文献
319.
An enantioselective total synthesis of hamacanthin B (1) is described. This synthesis is based on the asymmetric synthesis of (S)-2-azido-(indol-3-yl)ethylamine 7, which is coupled with the 3-indolyl-alpha-oxoacetyl chloride 8 and subsequently used in a successful intramolecular Staudinger-aza Wittig cyclization to form the central dihydropyrazinone ring. The stereochemistry of naturally isolated hamacanthin B is revealed as the (S)-configuration. 相似文献
320.
By the use of differential scanning calorimetry (DSC), a new method to measure the wax content of crude oil has been developed. In this paper, the wax content of a crude oil is proposed and proved to be the Q (total thermal effect of wax precipitation in sample) ratio of the crude oil and its corresponding wax obtained by using standard acetone method, i.e. Qoil/Qwax. For the 14 studied crude oils with the wax content ranging from 1 to 27 wt.%, the wax contents determined by the presented method are in good agreement with those determined by standard acetone method, with an absolute average deviation of only 0.82 wt.%. This method has an advantage over reported DSC methods in which the exact dissolution or precipitation enthalpy of wax is a must. It is also found that the wax contents determined by either of the two methods show good linear relationship with the total thermal effect Qoil, with the correlation coefficients over 0.96. According to the empirical correlations, the wax content of a crude oil can be easily determined by using the DSC total thermal effect Qoil. In addition and more significantly, the new method can be applied to improve the accuracy in determining the amount of precipitated wax in a waxy crude oil at different temperatures. 相似文献