293 resultados para 332.236


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We fabricated organic photovoltaic cells by using hexadecafluorophthalocyaninatocopper (F16CuPc) as electron acceptor material and para-sexiphenyl (p-6P) as electron donor material. F16CuPc has wide absorption spectrum from 550 nm to 850 nm, which covers the maximum of solar photo flux. The measurement of their external quantum efficiency (EQE) demonstrated that the photocurrent comes from the excitons created in F16CuPc, which were separated into free electrons and holes at heterojunction interface of p-6P and F16CuPc. Moreover, F(16)FuPc with excellent air-stability improved the environmental stability of photovoltaic cells, and the unencapsulated cells exhibited the shelf lifetime of exceeding a week.

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有机发光二极管(Organic Light-Emitting Diodes,OLEDs)以其制备工艺简单、成本低、发光颜色可在可见光区内任意调节以及易于大面积制作和柔韧弯曲等优点,被认为是未来重要的显示技术之一,在未来照明光源领域也显示了诱人的应用前景.一般认为,如果OLED的发光效率超过100 lm/W,就有可能取代一般照明.本文综述了实现白光OLED的方法及其最新进展,并对白光OLED存在的问题及其发展趋势进行了讨论.

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Surface morphology of polystyrene (PS) films on different substrates by spin-coating before and after annealing was observed using atomic force microscopy (AFM). The effects of polymer molecular weight, substrates, solvents, and annealing conditions on the morphology of the films were investigated. Before annealing, the grain height decreases, and simultaneously the grain diameter increases with molecular weight (M-w) within the measured molecular weight. After annealing. the situation is opposite, i.e., the grain height increases while the grain diameter decreases with M-w. Furthermore, after annealing the smaller surface roughness (Ra) was obtained. It was also found that film surface roughness (Ra) depends on the vapor pressure and dipole moment of different used solvents as well as the substrates. The experimental results show that when the used solvents have similar dipole moment but different vapor pressure, the Ra of PS film decreased with the decreasing vapor pressure of solvents whether on silicon or on mica. And when the used solvents have close vapor pressure but different dipole moment, the Ra decreased with the increasing of solvent dipole moments on both substrates.

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Dip-pen nanolithography (DPN) has been developed to pattern monolayer film of various molecules on suitable substrate through the controlled movement of ink-coated atomic force microscopy (AFM) tip, which makes DPN a potentially powerful tool for making the functional nanoscale devices. In this paper, the direct patterning of rhodamine 6G on mica by dip-pen nanolithography was demonstrated. R6G features patterned on the mica was successfully achieved with different tip movement which can be programmed by Nanoscript(TM) language. From the AFM image of R6G patterns, we know that R6G molecule is flatly binding to the mica surface through electrostatic interaction, thus stable R6G nanostructures could be formed on mica. The influence of translation speed and contact time on DPN was discussed. The method can be extended to direct patterning of many other organic molecules, and should open many opportunities for miniaturized optical device and site-specific biological staining.

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The fast analysis of ranitidine is of clinical importance in understanding its efficiency and a patient's treatment history. In this paper, a novel determination method for ranitidine based on capillary electrophoresis-electrochemiluminescence detection is described. The conditions affecting separation and detection were investigated in detail. End-column detection of ranitidine in 5 mM Ru(bpy)(3)(2+) solution at applied voltage of 1.20 V was performed. Favorable ECL intensity with higher column efficiency was achieved by electrokinetic injection for 10 s at 10 kV. The R.S.D. values of ECL intensity and migration time were 6.38 and 1.84% for 10(-4) M and 6.01 and 0.60% for 10(-5) M, respectively. A detection limit of 7 x 10(-8) M (S/N = 3) was achieved. The proposed method was applied satisfactorily to the determination of ranitidine in urine in 6 min.

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This paper presents results concerning structure and electrochemical characteristics of the La0.67Mg0.33 (Ni0.8Co0.1Mn0.1) (x) (x=2.5-5.0) alloy. It can be found from the result of the Rietveld analyses that the structures of the alloys change obviously with increasing x from 2.5 to 5.0. The main phase of the alloys with x=2.5-3.5 is LaMg2Ni9 phase with a PuNi3-type rhombohedral structure, but the main phase of the alloys with x=4.0-5.0 is LaNi(5)phase with a CaCu5-type hexagonal structure. Furthermore, the phase ratio, lattice parameter and cell volume of the LaMg2Ni9 phase and the LaNi5 phase change with increasing x. The electrochemical studies show that the maximum discharge capacity increases from 214.7 mAh/g (x=2.5) to 391.1 mAh/g (x=3.5) and then decreases to 238.5 mAh/g (x=5.0). As the discharge current density is 1,200 mA/g, the high rate dischargeability (HRD) increases from 51.1% (x=2.5) to 83.7% (x=3.5) and then decreases to 71.6% (x=5.0). Moreover, the exchange current density (I-0) of the alloy electrodes first increases and then decrease with increasing x from 2.5 to 5.0, which is consistent with the variation of the HRD. The cell volume reduces with increasing x in the alloys, which is detrimental to hydrogen diffusion and accordingly decreases the low-temperature dischargeability of the alloy electrodes.

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Assisted by a mechanical alloying and high-pressure technique, a new W4Mg intermetallic was formed. W4Mg amorphous mixture was obtained by mechanically alloying the pure metal powder mixtures at designated composition for 20 h. A new compound was found after the subsequent high-pressure and high-temperature treatment. W4Mg intermetallic was identified as a cubic structure and the lattice parameter was a=0.4150 nm. The synthesis mechanism is also discussed in this paper.

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The anion of MeO2CCH2CH2SnCl4 - was obtained by decomposing the yellow solution of MeO2CCH2CH2SnCl3.(2-OHC6H4CH=NC6H5) by standing for 15 days, which is the product of 3-methoxy-carbonylethyltin trichlorides with Schiff base (2-OHC6H4CH=NC6H5). The title compound was characterized by elemental analysis, IR. H-1 NMR,C-13 NMR and X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P2cn, a=7.852(2), b=12.236(1),c=16.952(4)Adegrees, V=1628.7 Angstrom(3), Z=4, D-c=1.79g/cm(3) F(000)=860, mu=22.2cm(-1), R=0.0449, Rw=0.0382. The title compound exists as a discrete molecule, and the tin atom attains a distorted octahedral geometry via the coordination of intramolecular carbonyl oxygen and chloride ion. The coordination number of tin atom is 6.

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在真空电弧炉内制备了LaNi<,2>和LaNi<,2.28>合金,在超高压下处理LaNi<,2>合金,得到了具有Laves相结构的AB<,2>型金属间化合物,采用机械合金化装置对上述铸造合金进行了球磨处理,制备了LaNi<,2.28>非晶合金粉末.利用这些合金制备储氢电极,与烧结镍阳极组成单电池,研究各种电极的充放电性能,得到如下结论:(1)LaNi<,2>和LaNi<,2.28>铸态合金电极的放电容量分别为199.4mAh/g和241.0mAh/g;(2)铸态AB<,2>合金的循环性能和放电容量高于Laves相结构的AB<,2>型合金;(3)非晶化的合金电极非常容易被活化,但循环性能和放电容量都远低于铸态合金电极.

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在用酯基锡MeO2CCH2CH2SnCl3合成配合物MeO2CCH2CH2SnCl3·(2-OHC6H4CH=NC6H5)时,其配合物的甲苯溶液放置培养单晶时(放置十天以上)会发生分解生成配合物MeO2CCH2CH2SnCl4—·H+。研究了标题化合物的合成反应,用元素分析、IR、NMR对配合物进行了表征,并测定了晶体结构。为正交晶系,空间群为P2cn, a=7.852(2), b=12.236(1), c=16.952(4) ? V=1628.7?, Z=4, Dc=1.79g/cm3, F(000)= 860,m=22.2cm—1(Mo),R=0.0449, Rw=0.0382。标题化合物的空间构型为畸变的八面体构型,中心锡原子的配位数为6。

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The theory of chemical shift effect of substituent was applied to the assignment of the C-13 NMR spectra of the ethylene/propylene and ethylene/octene-1 copolymers. Using the parameters derived above and the DEFT technique, we then entirely assigned the C-13 NMR spectra of the ethylene/propylene/octene(-1) terpolymers synthesized in the presence of the same heterogeneous supported Ziegler-Natta catalyst, TiCl4/MgCl2/i-Bu3Al. The present paper also covers the terpolymer composition and the monomer sequence distributions of a series of ethylene/propylene/octene-1 terpolymers.