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近年来,紧束缚模型方法被广泛应用于计算生物大分子体系.本文从第一性原理出发,根据紧束缚近似的思想,推导出生物大分子体系中的单电子运动方程.在此基础上给出了紧束缚模型方法中所涉及参数(在位能和迁移积分)的计算公式,在理论上完善了紧束缚模型方法.我们将所提出的参数化方法应用于理想B型DNA分子,给出了各种序列组合下的在位能和迁移积分.此外,我们还计算了周期性DNA分子poly(A)-poly(T)和poly(G)-poly(C)中空穴在位能和迁移积分随格点间距离的变化,为改进现有的SSH极化子模型提供了新的思路,有助于DNA中电荷输运的极化子机理的研究. 相似文献
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Precipitation polymerizations of divinylbenzene(DVB) in pure supercritical carbon dioxide,and parallel runs with presence of a cosolvent were carried out.The results showed that use of acetone as the cosolvent contributed greatly to the formation of the monodisperse microspheres.PDVB microspheres,with obviously higher uniformity than reported up to date,were achieved using 6-7 mL of acetone in a reactor of 50 mL with DVB concentration of 0.4 mol/L under 16 MPa,a much lower pressure than previously reported without use of cosolvent. 相似文献
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Wen Jing Zhao Yong Heng Shi Gui Long Zhao Yu Li Wang Hua Shao Li Da Tang Jian Wu Wang 《中国化学快报》2011,22(10):1215-1218
A series of gem-dimethyl-bearing C-glucosides were designed and synthesized as SGLT2 inhibitors,with anhydrous aluminum chloride-mediated Friedel-Crafts alkylation to construct the gem-dimethyl functionality being the key step.The in vivo anti-hyperglycemic activity was evaluated with mice oral glucose tolerance test(OGTT),and all the synthesized compounds showed significant but less potent anti-hyperglycemic activity than the positive control dapagliflozin. 相似文献
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Strong convergence theorems for approximation of common fixed points of asymptoticallyφ-quasi-pseudocontractive mappings and asymptoticallyφ-strictly- pseudocontractive mappings are proved in real Banach spaces by using a new compos- ite implicit iteration scheme with errors.The results presented in this paper extend and improve the main results of Sun,Gu and Osilike published on J.Math.Anal. Appl. 相似文献
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LONG Hao WANG Tian-hong ZHANG Ying-kuan State Key Laboratory of Microbial Technology Sh ong University Jinan P. R. China 《高等学校化学研究》2008,24(5):565-569
Two uridine auxotrophic mutants of Trichoderma reesei were isolated by resistance to 5-fluoroorotic acid after UV mutagenesis. One mutant, called M23, was complemented with the Aspergillus niger pyrG gene carried by plasmid pAB4-1. A mutated pyrG gene of M23 was cloned and DNA sequencing analysis indicated that a cytosine was inserted into the 934―939 oligo dC position of the pyrG coding region, resulted in a frameshift mutation. Transformation efficiency was approximately 200―300 transformants per microgram of DNA with plasmid pAB4-1. Stable transformants were obtained by monosporic culture and showed to be prototroph after successive propagation. Vitreoscilla hemoglobin expression plasmid pUCVHb was cotransformed with plasmid pAB4-1 and attained a transformation efficiency of 71.8% or of 26.1% with pAN7-1. Southern blot analysis of the transformants demonstrated that plasmid pUCVHb was integrated into the chromosomal DNA. The experimental results demonstrated that the pyrG-based system was more efficient and timesaving than the conventional hygromycin B resistance-based transformation system. 相似文献
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Hai Guang Zhang Xu Tang Tao Kao Shan Chen Chun Xue Yuan Shi Na Yan Min Hua Jiang 《中国化学快报》2011,22(6):647-650
A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibiy changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT) process,leading to off-on-off fluorescent molecular switching. 相似文献
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利用密度泛函理论和弹性散射格林函数方法,对硫醇分子膜的电学特性进行了理论模拟,计算结果表明,分子结的导电能力随着压力增加而增加,对单分子构成的分子结来说,电流的增加主要是由于电极距离的变化导致单个分子与电极的耦合增强,对于由多个分子构成的分子膜来说,由于外加压力的变化,导致分子结的链内隧穿和链间隧穿几率增大,从而导致导... 相似文献
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YUAN ChunXue XIN Qian LIU HuiJun WANG Lei JIANG MinHua & TAO XuTang State Key Laboratory of Crystal Materials Sh ong University Jinan China 《中国科学B辑(英文版)》2011,(4)
Trger's base (TB) is a well-known chiral molecule with rigid concave shape that makes it applicable in different areas such as superamolecular chemistry,molecular recognition,biological labeling,and so on.In this article,we briefly summarize some recent research progress in the optoelectronic properties of novel TB analogues and their applications in optoelectronic field with emphasis on the developments achieved in our group. 相似文献
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