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甲硫醛分子异构化反应的IRC解析
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作者 李学奎 李泽生 +2 位作者 孙家钟 赵成大 夏欣夫 《高等学校化学学报》 SCIE EI CAS 1987年第1期70-72,共3页
用IRC方法讨论了甲硫醛异构化反应机理,得到了过渡态和IRC路径,并进行了过渡态的振动分析。理论计算出的反应物几何构型与实验结果基本一致。
关键词 异构化反应 过渡态 几何构型 振动分析 IRC 反应物 甲硫
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Evaporation-induced Morphology Pattern of Triblock Copolymer A5B10C5 in Thin Film: a Multibody DPD Simulation Study 被引量:2
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作者 LI Yang WANG Dequan +4 位作者 WANG Wei LI Yanchun HUANG Xuri sun chiachung JIN Mingxing 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2014年第1期144-148,共5页
We used multibody dissipative particle dynamics method,by which the attractive and repulsive interactions can be effectively considered,to investigate the evaporation-induced morphology patterns of triblock copolymer ... We used multibody dissipative particle dynamics method,by which the attractive and repulsive interactions can be effectively considered,to investigate the evaporation-induced morphology patterns of triblock copolymer A5B10C5 in thin film.With changing attractive interactions between solvent vapor and triblock copolymer that represent various selective solvents,lamellar morphology,sandwich lamellar morphology,spherical morphology and disorder morphology patterns of the thin films were obtained for both coil-coil-coil and rod-coil-coil chain architectures,respectively.The order parameter and the film thickness were calculated during the process for characterizing the film properties,and it was found that the rigid A-block of the triblock copolymer hinders the formation of an ordered structure. 展开更多
关键词 Multibody dissipative particle dynamics Evaporation-induced Morphology pattern Thin film
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Theoretical study on the reaction of CN radicals with ClO radicals by density functional theory 被引量:1
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作者 YANG YuHong HUANG XuRi sun chiachung 《Science China Chemistry》 SCIE EI CAS 2009年第11期1973-1979,共7页
The reaction mechanism of CN radicals with ClO radicals has been studied theoretically using ab initio and density functional theory(DFT).The result shows that the main reaction path is the O atom in radical ClO attac... The reaction mechanism of CN radicals with ClO radicals has been studied theoretically using ab initio and density functional theory(DFT).The result shows that the main reaction path is the O atom in radical ClO attacks the C atom in radical CN to compose the intermediate 1 ClOCN.Three thermodynamically accessible prodncts,P1(CO+ClN),P3(NO+CCl),and P4(ClNCO),were obtained from intermediate 1 through isomerization and decomposition reactions.P4 is the primary product,and P1 and P3 are the secondary product.Compared with the singlet potential energy surface,the contribution of the triplet potential energy surface can be ignored. 展开更多
关键词 ab INITIO density functional theory(DFT) ClO+CN REACTION mechanism
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Electronic properties and stabilities of methoxy-substituted Lindqvist polyoxometalates [Nb_2W_4O_(19)CH_3]^(3-) by DFT
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作者 CONG Sha YAN LiKai +3 位作者 SONG Ping GUAN Wei SU ZhongMin sun chiachung 《Chinese Science Bulletin》 SCIE EI CAS 2012年第9期976-983,共8页
The electronic properties and stabilities of five [Nb2W4O18OCH3]3-isomers have been investigated using a density functional theory method.The results show that the isomer with the methoxy group occupying a bridging po... The electronic properties and stabilities of five [Nb2W4O18OCH3]3-isomers have been investigated using a density functional theory method.The results show that the isomer with the methoxy group occupying a bridging position between two tungsten atoms(two tungsten atoms in the plane that contains two niobium atoms) in the [Nb2W4O18OCH3]3-framework is the most stable isomer in acetonitrile.The stability of the one-electron-reduced isomers changes little.The most stable one-electron-reduced isomer has the methoxy group occupying a bridging position between niobium atoms in the [Nb2W4O18OCH3]4-framework.The M-Ob(M = Nb,W;b denotes bridging) bond lengths in anions in which the metal atoms are connected by a methoxy group are longer than those in [Nb2W4O19]4-.The highest occupied molecular orbitals(HOMO) in [Nb2W4O19]4-mainly delocalize over the bridging oxygen atoms of two niobium atoms and two tungsten atoms located in the equatorial plane,and the bridging oxygen atoms on the axial surface.The lowest unoccupied molecular orbitals(LUMO) of [Nb2W4O19]4-are mainly concentrated on the tungsten atoms and antibonding oxygen atoms.Methoxy substitution modifies the electronic properties of the [Nb2W4O18OCH3]3-isomers.The HOMOs in the five isomers formally delocalize over the bridging oxygen atoms,which are distant from the surface containing the methoxy group and four metal atoms.The LUMOs delocalize over the d-shells of the four metal atoms that are close to the methoxy group,and the p-orbitals of oxygen.One-electron reduction occurred at the tungsten atoms,not the niobium atoms. 展开更多
关键词 多金属氧酸盐 甲氧基 稳定性 电子性质 DFT 同分异构体 密度泛函理论方法 单电子还原
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Theoretical study of the P-Ylide reaction in the carbon nanotube
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作者 XIAO Bo ZHAO JingXiang +1 位作者 DING YiHong sun chiachung 《Science China Chemistry》 SCIE EI CAS 2009年第11期1969-1972,共4页
Recent studies have shown that the inner phase of carbon nanotubes(CNTs) can not only change the properties of molecules inside the tube,but also enhance or restrain the SN2 reactions.Thus,the CNTs can be considered a... Recent studies have shown that the inner phase of carbon nanotubes(CNTs) can not only change the properties of molecules inside the tube,but also enhance or restrain the SN2 reactions.Thus,the CNTs can be considered a form of solid solvent.In this paper,we study the [2+2] cycloaddition reaction between CH2O and PH3CH2 in the gas phase,benzene solution and inner phase of CNT using the density functional theory(DFT).The results indicate that the inner phase of CNT has little effect on the [2+2] cycloaddition reaction.This can be explained as that while taking the linear arrangement for SN2 reaction,the reactants do not possess the axial symmetry for the studied [2+2] cycloaddition reaction.Therefore,although the CNT has large axial polarizability,it can exert little influence on the [2+2] cycloaddition reaction.Our studies will be helpful for further understanding of the inner phase chemistry of CNTs. 展开更多
关键词 CNT [2+2] CYCLOADDITION REACTION density functional theory(DFT)
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PbCNN:A molecule containing Pb≡C bonding
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作者 ZHANG WenBin SHI GuoSheng +1 位作者 DING YiHong sun chiachung 《Science China Chemistry》 SCIE EI CAS 2009年第3期313-317,共5页
In order to predict potential molecules with Pb≡C bonding, we investigated the potential energy sur-face of a tetra-atomic system [PbCN2] at the CCSD(T)//B3LYP level. We found that the linear isomer PbCNN possesses g... In order to predict potential molecules with Pb≡C bonding, we investigated the potential energy sur-face of a tetra-atomic system [PbCN2] at the CCSD(T)//B3LYP level. We found that the linear isomer PbCNN possesses good thermodynamic and kinetic stability. The combined molecular orbital analysis, hydrogenation heat, bond energy and bond dissociation energy all proved that PbCNN is composed of Pb≡ C triple bonding. 展开更多
关键词 PbCNN TRIPLE BONDING POTENTIAL energy surface
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Theoretical studies of interaction models of human acetylcholine esterase with different inhibitors
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作者 ZHENG QingChuan CHU HuiYing +1 位作者 NIU RuiJuan sun chiachung 《Science China Chemistry》 SCIE EI CAS 2009年第11期1911-1916,共6页
Alzheimer's disease(AD) is a progressive neurodegenerative disorder and one of the most common causes of dementia in the elderly.Acetylcholine esterase inhibitors(AChEI) are the main drugs used in the treatment of... Alzheimer's disease(AD) is a progressive neurodegenerative disorder and one of the most common causes of dementia in the elderly.Acetylcholine esterase inhibitors(AChEI) are the main drugs used in the treatment of AD.In this work,docking studies have been performed in order to understand the interaction between a number of inhibitors(tacrine,rivastigmine,huperzine A,TV-3326(ladostigil),donepezil and anseculin) and acetylcholine esterase(AChE).The calculated binding affinities between inhibitors and AChE increase in the order tacrine<rivastigmine<huperzine A<TV-3326<donepezil<anseculin,which reflects the experimental inhibitory activity expressed in terms of the half maximal inhibitory concentration(the IC50 value).Of the above inhibitors,anseculin is the most useful drug for the treatment of dementia. 展开更多
关键词 Alzheimer’s disease ACETYLCHOLINE ESTERASE INHIBITOR DOCKING
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A molecular dynamics and computational study of human KAT3 involved in KYN pathway
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作者 XU Yu ZHENG QingChuan +2 位作者 YU LiYing ZHANG HongXing sun chiachung 《Science China Chemistry》 SCIE EI CAS 2013年第4期514-523,共10页
Kynurenine aminotransferases (KATs) catalyze the transamination of kynurenine (KYN) pathway and endogenous KYNs have been suggested to highly correlate to abnormal brain diseases. HKAT3 is a key member of KAT fami... Kynurenine aminotransferases (KATs) catalyze the transamination of kynurenine (KYN) pathway and endogenous KYNs have been suggested to highly correlate to abnormal brain diseases. HKAT3 is a key member of KAT family, while the binding mechanism of KYN and cofactor with HKAT3 has not been determined yet. In this study, we focus on the structure-function relationship among KYN, cofactor and HKAT3. The binding models of KYN complex and KYN&cofactor complex were ob- tained and were studied by molecular dynamics (MD) simulations. We identified several critical residues and influence of conformational changes in human kynurenine aminotransferase 3 (HKAT3) complexes. The cofactor may contribute largely not only to the catalysis, but also to the binding. In addition, a hypothesis is proposed that a strong hydrophobic interaction between Tyr159 and Lys280 may influence the binding mode and the binding region of the substrate and the cofactor. Our re- suits will be a good starting point for further determination of the biological role. 展开更多
关键词 kynurenine (KYN) kynurenine aminotransferases (KATs) ^-~ interaction molecular dynamic (MD) simulation interaction energy
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