检索结果-南通市图书馆

Geometric and Electronic Structure of Squaric Acid from DFT Calculation

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2004年第2期20卷 206-208页

作者： Xuyan XUE, Chunlei WANG and Weilie ZHONGSchool of Physics and Microelectronics, State key laboratory of crystal materials, shandong university, jinan 2.0100, china shandong Univ Sch Phys & Microelect State Key Lab Crystal Mat Jinan 250100 Peoples R China

The crystal and electronic structure of antiferroelectric squaric acid is studied using density functional theory method, and the exchange correlation effects are treated by the generalized approximation. In order to understand the ferroelectricity of H2SQ in the molecular plane and the antiferroelectricity in whole crystal, the density of states, charge density distribution and band structure are calculated. The result showed that O2p and C2p play important roles in the interactions between layers. The hybridizations of 02s-Hls and 02p-Hls are responsible for the tendency to ferroelectricity within each layer.

关键词： Antiferroelectricity Electronic structure Squaric acid

Electron transport properties of boron-doped capped-carbon-nanotube-based molecular junctions

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2010年第36期55卷 4104-4107页

作者： ZHAO Peng1 & LIU DeSheng2 1 School of Science, university of jinan, jinan 250022, china 2 School of Physics, State key laboratory of crystal materials, shandong university, jinan 2.0100, china School of Science University of Jinan Jinan 250022 China School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China

Using the Landauer formalism that combines both the non-equilibrium Green’s function and first-principles density functional theory, the electron transport properties of a one-dimensional molecular junction based on capped carbon nanotubes with boron doping at various sites are investigated. The results show that the electron transport properties are strongly dependent on the boron-doping site. Negative differential resistance behavior can be observed when boron-atom dopants are present in the tip region.

关键词： carbon nanotube doping non-equilibrium Green’s function density functional theory

A first-principles study of dihydroazulene as a possible optical molecular switch

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2011年第3期Mechanics & Astronomy) .卷 437-441页

作者： XIA CaiJuan1, LIU DeSheng2,3 & LIU HanChen1 1 School of Science, Xi’an Polytechnic university, Xi’an 710048, china 2 School of Physics, State key laboratory of crystal materials, shandong university, jinan 2.0100, china 3 Department of Physics, Jining university, Qufu 273155, china 1. School of Science Xi’an Polytechnic University Xi’an 710048 China2. School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China3. Department of Physics Jining University Qufu 273155 China

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of the dihydroazulene optical molecular switch. Three kinds of adsorption sites including the hollow, bridge and top sites are studied. The two forms of this molecule, namely the open form and the closed form, can reversibly switch from each other upon photoexcitation. Their transmission spectra are remarkably distinctive. Theoretical results show that the current of the closed form is always significantly larger than that of the open form for all three adsorption sites, which promises this system as possibly one of the good candidates for optical switches due to its unique advantage, and which may have some potential applications in the future molecular circuit.

关键词： molecular switch nonequilibrium Green’s function electronic transport density functional theory

Theoretical Study on the Structure and Vibrational Spectra for 4-methyl-3-penten-2-one

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第10期10卷 835-838页

作者： Dong Mei DU Ai Ping FU Zheng Yu ZHOU (Department of Chemistry. Qufu Normal university, shandong, Qufu 273165 2 State key laboratory of crystal materials. shandong university, shandong, jinan 2.0100) Qufu Normal Univ Dept Chem Shandong 273165 Qufu Peoples R China shandong Univ State Key Lab Crystal Mat Jinan 250100 Peoples R China

Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals), nb initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of 4-methyl-3-penten-2-one. The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the functional vibrational modes.

关键词： density functional theory vibrational spectra 4-methyl-3-penten-2-one

Ground state and polaron and bipolaron excited states in polydiacetylene

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 430-439页

作者： LI Yuan1, HU Guichao1, XIA Caijuan1, LIU Desheng1,2 & XIE Shijie1,2 1. School of Physics and Microelectronics, shandong university, jinan 2.0100, china 2. National key laboratory of crystal materials, shandong university, jinan 2.0100, china 1. School of Physics and Microelectronics Shandong University Jinan 250100 China 2. National key laboratory of crystal materials Shandong University Jinan 250100 China

The electronic properties of ground state and charged excited states of nondegenerate polydiacetylene were investigated by means of a tight-binding model. The parameters of the model were obtained by comparison of the experimental and other theoretical results. It was found that there is a stable dimerized structure of polydiacetylene in ground state and the doping induces the nonlinear excitations, such as polarons and bipolarons. In order to compare the stability of polaron and bipolaron, the creation energy and binding energy were separately defined. By neglecting the electron-electron Coulomb interaction, a bipolaron is more stable than two independent polarons.

关键词： dimerization, polaron, bipolaron, binding energy.

Multi-carbazole derivatives for two-photon absorption data storage:Synthesis,optical properties and theoretical calculation

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2010年第4期53卷 884-890页

作者： LI Lin1, YANG JiaXiang1,2, WANG CaiXia1, HU ZhangJun1, TIAN YuPeng1,2, LI Jing3, WANG ChuanKui3, LI Ming4, CHENG GuangHua4, TANG HuoHong5, HUANG WenHao5, TAO XuTang2 & JIANG MinHua2 1Department of Chemistry, Anhui university, Hefei 230039, china 2.tate key laboratory of crystal materials, institute of crystal materials of shandong university, jinan 2.0100, china 3Department of Physics, shandong Normal university, jinan 250014, china 4State key laboratory of Transient Optics and Photonics, Xi’an institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, china 5Department of Precision Machinery and Precision Instrumentation, university of Science and Technology of china, Hefei 230026, china 1. Department of Chemistry Anhui University Hefei 230039 China2. State Key Laboratory of Crystal Materials Institute of Crystal Materials of Shandong University Jinan 250100 China3. Department of Physics Shandong Normal University Jinan 250014 China4. State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710119 China5. Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei 230026 China

Two novel quadrupolar organic compounds, 3-(4-((E)-2-(9-butyl-9H-carbazol-6-yl) vinyl)styryl)-9-propyl-9H-carbazole (BCSPC) and 3-(3-(3-((1E)-2-(4-((E)-2-(3-(3,5-bis(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazol-6-yl)vinyl)phenyl) vinyl)-9-butyl-9H-carbazol-6-yl)-5-(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazole (BCPBC), with different conjugated arms, have been designed and synthesized. Their one-and two-photon absorption (TPA) and excited fluorescence properties have been experimentally investigated. The two-photon absorption cross-sections of two compounds were estimated by two-photon excited fluorescence technique using 200 fs, 76 MHz, Ti:sapphire laser, which are 22 and 154 GM for BCSPC and BCPBC, respectively. The optimal excitation wavelengths are 780 nm for both BCSPC and BCPBC. A data recording experiment proved the potential application of the materials.

关键词： initiator optical data storage fluorescence two-photon absorption theoretical calculation

Electron Transfer Reaction between M-C_6H_6 and M^+-C_6H_6 Complexes in the Gas Phase: Density Functional Theory Study

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2000年第3期11卷 219-222页

作者： Ai Ping FU, Dong Mei DU, Zheng Yu ZHOU (Department of Chemistry, Qufu Normal university,shandong. Qufu 273165 State key laboratory crystal materials shandong university, shandong. jinan 2.0100) Qufu Normal Univ Dept Chem Shandong 273165 Qufu Peoples R China shandong Univ State Key Lab Crystal Mat Jinan 250100 Peoples R China

DFT/BLYP method is used to theoretically investigate the electron transfer (ET) reactions between M (Li, Na, Mg)-C_6H_6 and M+-C_6H_6 complexes in the gas phase. The geometry optimization of the precursor complexes and the transition state in the process of ET reaction was performed at 6-31G basis set level. The activation energy. the coupling matrix element and the rate constant of the ET reaction are calculated at semi-quantitative level.

关键词： M-C_6H_6 complex density functional theory rate constant.

Size Determination of Ultramicropores and Small Mesopores Using a Calculation Procedure Based on the Tangents of Comparison Plot

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(materials Science) 2010年第3期25卷 391-394页

作者：邱芹刘世权 School of materials Science and Engineering University of Jinan

Pore size distribution（PSD） curves of synthesized hollow silica spheres with ultrmicropores and small mesopores were obtained from calculations based on the BJH,KJS,SF,MP,NLDFT models and ***＇s *** indicate that Zhu＇s method not only gives reasonable small mesopore size but also could be further extended to the ultramicropores region for the PSD evaluation.

关键词： pore size distribution comparison plot ultramicropores mesopores

SOS Calculation of Nonlinear Optical Propertiesof Synthesized ASPBPh_4

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2001年第2期17卷 207-211页

作者： ZHAO Xian, TIAN Yu-peng, ZHOU Yu-fang and JIANG Min-hua (State key laboratory of crystal materials, shandong university, jinan 2.0100, P. R. china) LIU Yong-jun and HU Hai-quan (institute of Theoretical Chemistry, shandong university, jinan 2.0100) 山东大学晶体材料国家重点实验室山东济南 250100 山东大学山东济南 250100

The two-photon absorption induced lasing spectrum shows that the synthesized ASPBPh4, trans-4- [p- (N-methyl-N- (hydroxyethyl)amino) styryl]-N-methylpyridinium, has a distinct ef- ficiency of laser frequency up-conversion. This nonlinear optical property of such a kind of com- pounds is related to two-photon absorption (TPA). In our work, we used the intermediate ne- glect of differential overlap (INDO) plus single-excitation configuration interaction (SCI) method to get the basic properties of the molecule, and calculated the second hyperpolarizability and the cross section of two-photon absorption by means of sum-over-state (SOS) expression. The rela- tionship between the structure and the properties is discussed.

关键词： Two-photon absorption Semiempirical method Sum-over-state