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71.
Using intercalated, covalently bound daunomycin as a redox probe, ground state charge transport in DNA films with a perturbation in base pair stacking was examined in comparison with breaks in the sugar-phosphate backbone. While the introduction of one or even two nicks in the sugar-phosphate backbone yields no detectable effect on electron transfer, a CA mismatch significantly attenuates the electron transfer yield. These results confirm that the base pair stack is the pathway for DNA-mediated charge transfer, not the sugar-phosphate backbone. 相似文献
72.
73.
The covalent binding of acrylonitrile (CH(2)=CH-C triple bond N) and the formation of a C=C-C=N structure on Si(100) have been investigated using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) calculations. For chemisorbed acrylonitrile, the absence of nu(C triple bond N) at 2245 cm(-1) and the appearance of nu(C=N) at 1669 cm(-1) demonstrate that the cyano group directly participates in the interaction with Si(100), which is further supported by XPS and UPS observations. Our experimental results and DFT calculations unambiguously demonstrate a [2 + 2] cycloaddition mechanism for acrylonitrile chemisorption on Si(100) through the binding of C triple bond N to Si dimers. The resulting chemisorbed monolayer with a C=C-C=N skeleton can serve as a precursor for further chemical syntheses of multilayer organic thin films in a vacuum and surface functionalization for in situ device fabrication. 相似文献
74.
NH_2基态和激发态的SAC-CI和量子拓扑方法研究郑世钧,蔡新华,宋天乐,孟令鹏,中迁博,波田雅彦(河北师范学院化学系,石家庄,050091)(京都大学工程学院京都,日本)关键词SAC-CI方法,激发态,电子密度,拓扑分析用量子拓扑学方法研究激发态... 相似文献
75.
Yan-Qing Wang Hong-Mei Zhang Gen-Cheng Zhang Wei-Hua Tao Shu-He Tang 《Journal of Molecular Structure》2007,830(1-3):40-45
The feature of brucine binding to human serum albumin (HSA) was investigated via fluorescence and UV/vis absorption spectroscopy. The results revealed that brucine caused the fluorescence quenching of HSA by the formation of brucine–HSA complex. The hydrophobic interaction plays a major role in stabilizing the complex; the binding site number n and apparent binding constant KA, corresponding thermodynamic parameters the free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) at different temperatures were calculated. The distance r between donor (HSA) and acceptor (brucine) was obtained according to fluorescence resonance energy transfer. The effect of brucine on the conformation of HSA was analyzed using synchronous fluorescence spectroscopy and UV/vis absorption spectroscopy. 相似文献
76.
在低钯含量活性非均布Pd/Al2O3催化剂上,实现了富氧条件下,氢部分选择性催化还原NO过程,低温、富氧条件下NO的转化率高达80%-100%。NO直接分解实验表明,600℃,NO分解转化率在无氧时为17.3%,有0.5%氧存在时接近于0。氢非选择性还原NO条件下,100℃以下,NO转化率为100%。根据实验结果及文献,推测了氢部分选择性还原NO过程中可能存在的反应,不同的反应温度下,NO脱除反应有所不同。在115℃以下,NO还原产物为NH3;115℃-155℃,NO还原产物为NH3、N2O和N2;155℃以上,NO还原产物中无NH3存在。NO还原反应与氢氧反应是平行的竞争反应。 相似文献
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78.
Ju Tao LIU Xiao Hong WANG Jing Fu LIU Faculty of Chemistry Northeast Normal University Changchun 《中国化学快报》2004,15(7):859-862
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pi, a = 8. 4960 (17), b = 10.447 (2), c = 11.299 (2) A, α= 68. 82 (3)°,β= 87.35 (3)°, γ = 66.97(3)°. V = 855. 3(3) A3, Z = 8, R1 = 0. 0857, wR2=0. 2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid. 相似文献
79.
80.
Dependence of Performance of Organic Light-emitting Devices on Sheet Resistance of Indium-tin-oxide Anodes 总被引:2,自引:0,他引:2
ZHOU Liang ZHANG Hong-jie YU Jiang-bo MENG Qing-guo PENG Chun-yun LIU Feng-yi DENG Rui-ping PENG Ze-ping LI Zhe-feng 《高等学校化学研究》2006,22(4):427-431
IntroductionIndium-tin-oxide(ITO) has been widely used asthe anode material in organic light-emitting devices(OLEDs) because of its high transmittance in the visi-ble region and low electrical resistivity. In the pastyears, many investigations focused on … 相似文献