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991.
K. J. Chen F. Y. Hung S. J. Chang S. J. Young Z. S. Hu S. P. Chang 《Journal of Sol-Gel Science and Technology》2010,54(3):347-354
The multi-compound ZITO transparent conductive oxide (TCO) thin films were synthesized using the sol–gel method. The ZITO
thin films with various volume ratios of ZnO to ITO (1:1, 2:1 and 9:1) were crystallized at different temperatures (600–700 °C).
The results showed that the crystalline characteristics and optical transmittance were mainly dependent on ITO content and
crystallization. Notably, the 650 °C Z9ITO film not only had better conductivity but also possessed excellent optical transmittance. In addition, the surface roughness
of the ZITO films and optoelectric properties of IZO (indium doped ZnO) films were analyzed to confirm the contribution of
indium dopants on the optical transmittance. Also, the ZITO films were subjected to the effects of indium and tin dopants
and this improved the related characteristics of ZnO films. 相似文献
992.
This work exploited a sequential injection lab-on-valve (LOV) system for the determination of cadmium by anodic stripping voltammetry (ASV). A miniaturized electrochemical flow cell (EFC) was fabricated in LOV, in which a nafion coated bismuth film electrode was used as working electrode. The cadmium was electrodeposited on the electrode surface in bismuth solution, and measured with the subsequential stripping scan. Under optimal conditions, the proposed system responded linearly to cadmium concentrations in a range 2.0-100.0 μg L−1. The detection limit of this method was found to be 0.88 μg L−1. By loading a sample volume of 800 μL, a sampling frequency of 22 determinations h−1 was achieved. The repeatability expressed as relative standard derivation (R.S.D.) was 3.65% for 20 μg L−1 cadmium (n = 11). The established method was applied to analysis of trace cadmium in environmental water samples and the spiked recoveries were satisfactory. 相似文献
993.
Jiang F Wang Y Hu X Shao N Na N Delanghe JR Ouyang J 《Journal of separation science》2010,33(21):3393-3399
The application of pore-gradient polyacrylamide gel electrophoresis (PG-PAGE) incorporated with carbon nanotube modified by Triton X-100 and carboxylation so as to improve the separation of human serum proteins is reported. The novel PG-PAGE was made by adding water-soluble single-walled carbon nanotubes (CNTs) when preparing the polyacrylamide gel. Significant improvements in separation of complement C3 protein and haptoglobin (Hp) in human serum were achieved. It was estimated that the interactions between the hydrophilic groups on the proteins and the surface of the CNTs result in different adsorption kinetics of complement C3 and Hp subtype on the nanoparticles incorporated in the gel, thus enhancing the separation of the two proteins in serum. This new CNT matrix-assisted PG-PAGE method for enhanced separation of complement C3 and Hp in human serum was successfully applied to distinguish the samples from liverish patients and healthy people. 相似文献
994.
采用模拟方法研究组蛋白脱乙酰酶抑制剂(Apicidin)选择性抑制组蛋白去乙酰化酶(Histone deacetylases, HDACs)中的HDAC1和HDAC8. 通过HDAC8晶体结构同源模建HDAC1三维结构模型, 将Apicidin分别与HDAC1和HDAC8对接并进行分子动力学模拟, 结果表明, HDAC1活性口袋入口处的Arg270是Apicidin-HDAC1形成稳定结构的重要因素; HDAC1中Tyr303及His178与Apicidin形成2个持续存在的氢键, 而在HDAC8中未发现, 这是Apicidin选择性抑制HDAC1高于HDAC8的另一重要原因. 相似文献
995.
利用新型材料金纳米空球, 通过层层修饰的技术, 分别将壳聚糖、空壳纳米金、L-半胱氨酸、细胞色素c以及ssDNA探针修饰到玻碳电极表面, 制备了一种新型的DNA生物传感器. 以紫外及透射电子显微镜(TEM)表征了空壳纳米金, 以循环伏安法、阻抗谱图等电化学方法研究了传感器的特性, 通过原子力显微镜方法观察了该DNA生物传感器不同层之间的形态差异. 结果表明, 该修饰电极所吸附的ssDNA探针为1.672×10―10 mol•cm-2. 在指示剂柔红霉素的帮助下, DNA探针可与互补的DNA进行杂交, 借此以微分脉冲伏安法测定DNA. 相似文献
996.
Three new caged prenylxanthones (xanthone=9H‐xanthen‐9‐one), named neobractatin ( 1 ), 3‐O‐methylneobractatin ( 2 ), and 3‐O‐methylbractatin ( 3 ), along with eight known compounds, were isolated from the twig of Garcinia bracteata. The structures of the new compounds were elucidated on the basis of 1D‐ and 2D‐NMR experiments, including HMBC, HSQC, 1H,1H‐COSY, and ROESY, as well as HR‐MS analysis. 相似文献
997.
An effective column‐switching counter‐current chromatography (CCC) protocol combining stepwise elution mode was successfully developed for simultaneous and preparative separation of anti‐oxidative components from ethyl acetate extract of traditional Chinese herbal medicine Rubia cordifolia. The column‐switching CCC system was interfaced by a commercial low‐pressure six‐port switching valve equipped with a sample loop, allowing large volume introduction from the first dimension (1st‐D) to the second dimension (2nd‐D). Moreover, to extend the polarity window, three biphasic liquid systems composed of n‐hexane/ethyl acetate/methanol/water (1:2:1:2, 2:3:2:3, 5:6:5:6 v/v) were employed using stepwise elution mode in the 1st‐D. By valve switching technique the whole interested region of 1st‐D could be introduced to second dimension for further separation with the solvent system 5:5:4:6 v/v. Using the present column‐switching CCC protocol, 500 mg of crude R. cordifolia extract were separated, producing milligram‐amounts of four anti‐oxidative components over 90% pure. Structures of purified compounds were identified by 1H and 13C NMR. 相似文献
998.
Cheng Guo Jieping Wan Nan Hu Kezhi Jiang Yuanjiang Pan 《Journal of mass spectrometry : JMS》2010,45(11):1291-1298
The dissociation pathways of protonated enaminones with different substituents were investigated by electrospray ionization tandem mass spectrometry (ESI‐MS/MS) in positive ion mode. In mass spectrometry of the enaminones, Ar? CO? CH?CH? N(CH3)2, the proton transfers from the thermodynamically favored site at the carbonyl oxygen to the dissociative protonation site at ipso‐position of the phenyl ring or the double bond carbon atom adjacent to the carbonyl leading to the loss of a benzene or elimination of C4H9N, respectively. And the hydrogen? deuterium (H/D) exchange between the added proton and the proton of the phenyl ring via a 1,4‐H shift followed by hydrogen ring‐walk was witnessed by the D‐labeling experiments. The elemental compositions of all the ions were confirmed by ultrahigh resolution Fourier transform ion cyclotron resonance tandem mass spectrometry (FTICR‐MS/MS). The enaminones studied here were para‐monosubstituted on the phenyl ring and the electron‐donating groups were in favor of losing the benzene, whereas the electron‐attracting groups strongly favored the competing proton transfer reaction leading to the loss of C4H9N to form a benzoyl cation, Ar‐CO+. The abundance ratios of the two competitive product ions were relatively well‐correlated with the σp+ substituent constants. The mechanisms of these reactions were further investigated by density functional theory (DFT) calculations. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
999.
Hsin‐Chung Cheng Chau‐Hsiang Wang Chiung‐Fang Huang Yung‐Kang Shen Yi Lin Dong‐Yea Sheu Yi‐Han Hu 《先进技术聚合物》2010,21(9):632-639
In this study, master of the microlens arrays is fabricated using micro dispensing technology, and then electroforming technology is employed to replicate the Ni mold insert of the microlens arrays. Finally, micro hot embossing is performed to replicate the molded microlens arrays from the Ni mold insert. The resin material is used as the dispensing material, which is dropped on a glass substrate. The resin is exposed to a 380 W halogen light. It becomes convex under surface tension on the glass substrate. A master for the microlens arrays is then obtained. A 150‐nm‐thick copper layer is sputtered on the master as an electrically conducting layer. The electroforming method replicates the Ni mold insert from the master of the microlens arrays. Finally, micro hot embossing is adopted to replicate the molded microlens arrays. The micro hot embossing experiment employs optical films of polymethylmethacrylate (PMMA) and polycarbonate (PC). The processing parameters of micro hot embossing are processing temperature, embossing pressure, embossing time, and de‐molding temperature. Taguchi's method is applied to optimize the processing parameters of micro hot embossing for molded microlens arrays. An optical microscope and a surface profiler are utilized to measure the surface profile of the master, the Ni mold insert and the molded microlens arrays. AFM is employed to measure the surface roughness of the master, the Ni mold insert and the molded microlens arrays. The sag height and focal length are determined to elucidate the optical characteristics of the molded microlens arrays. Copyright © 2009 John & Sons, Ltd. 相似文献
1000.
The structural properties, phase stability, electronic structure, elastic properties, and optical properties of Ca5(PO3)4F (FA), Ca5(PO3)4Cl (ClA) and Ca5(PO3)4Br (BrA) are studied by DFT calculations with the generalized gradient approximation. 相似文献