检索结果-南通市图书馆

Theoretical Research on Scattering Resonance States of Reaction I＋HI（v=O）→IH（v＇=0）＋I： Partial Potential Energy Surface and One-dimensional Quantum Reactive Scattering Calculation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2006年第5期19卷 411-415页

作者： Hua-yang Wang Xiao-min Sun Zheng-ting Cai da-cheng feng Institute of Theoretical Chemistry Shandong University Ji＇nan 250100 China

Based on the vibrational potential curves coupled with the minimum energy reaction path, the partial potential energy surface of the reaction I＋HI→IH＋I was constructed at the QCISD（T）//MP4SDQ level with pseudo potential method. And the formation mechanism of the scattering resonance states of this reaction was well interpreted with the partial potential energy surface. The scattering resonance states of this reaction should belong to Feshbach resonance because of the coupling of the vibrational mode and the translational mode. With the one-dimensional square potential well model, the resonance width and lifetime of the I＋HI（v=0）→IH（v＇=0）＋I state-to-state reaction were calculated, which preferably explained the high-resolved threshold photodetachment spectroscopy of the IHI- anion performed by Neumark et al..

关键词： Partial potential energy surface Scattering resonance states Scattering resonance width and lifetime One-dimensional square potential well model

Theoretical Study of the Scattering Resonance State, Reaction Mechanism and Partial Potential Energy Surface of the F+CH4→HF+CH3 Reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第2期17卷 281-284页

作者： Qiang WANG Zheng Ting CAI da cheng feng Institute of Theoretical Chemistry Shandong University Jinan 250100

The partial potential energy surface was constructed by ab initio method [QCISD（T）/6- 311＋＋G（2df,2pd）]for F＋CH4→HF＋CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Troya by means of quasiclassical trajectory （QCT） but also successfully validated Kopin Liu＇s experimental phenomena about the existence of the reactive resonance. The lifetime of the scattering resonance state was about 0.07 ps. All these were in agreement with the experiments.

关键词： The partial potential energy surface (PPES) asymmetrical heavy-light-heavy system dynamic Eyring lake the lifetime of the scattering resonance state.

Syntheses and Crystal Structures of Four New Complexes [Mn(4,4′-bip)_2(OH_2)_4](DBA)·4H_2O and [M(OH_2)(HDPA)_2]·3H_2O (M = Mn,Co,Ni)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2006年第8期25卷 895-902页

作者： LIU Ying DOU Jian-Min WANG da-Qi LI da-cheng XU feng ZHOU Lei SU Huai-Jing College of Chemistry and Chemical Engineering Liaocheng University 252059 China

Four new transition metal complexes, [Mn（4,4′-bip）2（OH2）4]（DBA）-4H2O 1 （4,4′-hip = 4,4′-bipyridine, H2DBA = benzene-1,3-dicarboxylic acid） and [M（OH2）（HDPA）2]-3H2O （M = Mn 2, M = Co 3, M = Ni 4, H2DPA = 2,6-pyridine-dicarboxylic acid）, have been prepared from the reaction of transition metals and carboxylic acids, and characterized by X-ray and elemental analyses. For compound 1, the packing diagram shows that a three-dimensional network is formed via hydrogen bonds and strong π-πinteractions. For compounds 2, 3 and 4, a double-helical chain is formed through hydrogen bonds. Moreover, a three-dimensional network is constructed from chains via complicated hydrogen bonds between crystal water molecules and oxygen atoms of HDPA^-.

关键词： manganese cobalt nickel 4,4′-bipyridine benzene-1,3-dicarboxylic acid 2,6-pyridine-dicarboxylic acid X-ray analysis

Synthesis, Structure, and Magnetic Properties of One Polyoxometalate (W/Mo) Compound: H_8K{[Ni(H_2O)_5]_2(H_2Mo_(1.80)W_(10.20)O_(42))}Cl_3·16H_2O

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2007年第5期26卷 599-605页

作者： LIU Ying DOU Jian-Min WANG da-Qi ZHANG Xian-Xi LI da-cheng XU feng ZHOU Lei College of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 China

One new polyoxometalate compound connected via nickel/potassium cations, H8K{[Ni（H2O）5]2（H2Mo1.80W10.20O42）}Cl3·16H2O 1, was prepared and characterized by elemental analysis and IR spectroscopy. Single-crystal X-ray diffraction analysis results reveal that clusters of [Ni（H2O）5]2（H2Mo1.80W10.20O42）}^6-in compound 1 are linked by potassium cations to form one- dimiensional chains, based on which a three-dimensional network is further constructed via the hydrogen bonds of O…O and O…Cl. Magnetic measurements show that compound 1 has paramagnetic properties. Crystal data： H62Cl3KMo1.80Ni2O68W10.20, Mr = 3461.33, monoclinic, space group C2/c, a = 18.9291（19）, b = 16.6758（17）, c = 19.1064（19）A, β = 106.6880（10）°, V = 5777.1（10）A^3, Z = 4, Dc = 3.980 g/cm^3, F（000） = 6250, μ = 21.574 mm^-1, R = 0.0579 and wR = 0.1623 （Ⅰ 〉 2σ（Ⅰ））.

关键词： polyoxomolybdate molybdate nickel sodium X-ray analysis magnetic

DFT Study on One-carbon Unit Transfer from 1,10-CH^+- tetrahydroquinoxaline to Methylamine

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第1期14卷 72-75页

作者： Chuan Song QI da cheng feng Hua Yang WANG Zheng Ting CAI Institute of Theoretical Chemistry Shandong UniversityJinan 250100

Density Functional Theory (DFT) method was used in this paper to study one-carbon transfer from 1,10-tetrahydroquinoxaline, an analogue of tetrahydrofolic acid, to methylamine. This reaction can be completed via two paths. From the computation result we can conclude that a general-acid catalysis exists in this reaction. By computation we find DFT has its limitation in describing a newly incorporated structure with a unit charge.

关键词： Density Functional Theory (DFT) folate cofactor tetrahydroquinoxaline one-carbon unit transfer.

Ground State Spins of Bicarbcnes and Binitrenes,Coupled through Electron-Rich Rings

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第11期10卷 937-940页

作者： Hai Quan HU Yong Jun LIU da cheng feng cheng Bu LIU(Institute of Theoretical Chemistry, Shandong University, Jinan 250010) Institute of Theoretical Chemistry Shandong University Jinan 250010 China

The ground state spins coupled through electron-rich rings of bicarbenes and binitreneshave been studied at UHF/6-31G* level. The results demonstrate that ferromagnetic couplingexists in these molecules, and electron-... 详细信息

关键词： Electron-rich ring ferromagnetic coupling bicarbene binitrene.

The Quantum Scattering Study for Ion-pair Formation Reaction Na+I_2→Na^+I_2^- with the LCAC-SW method

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第4期10卷 325-326页

作者： Wan Yong MA da cheng feng Zheng Ting CAI Cong Hao DENG(Institute of Theoretical Chemistry, Shandong University, Jinan 250100) Institute of Theoretical Chemistry Shandong University Jinan 250100 China

The selected-state probabilities of collinear ion-pair formation process Na+I2→Na++I2-on Aten-Laming-Los two-State potential energy surface have been calculated by using LCAC-SW method. The results show that reaction probabilities are oscillatory with collision energy; the threshold energy of this ioniZation reaction is 2.8 ev, which is in modest agreement with experimental result.

关键词： Ion-pair formation reaction probability quantum scattering LCAC-SW method

Performance analysis of rate-adaptive cooperative MAC based on wireless local area networks

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第5期16卷 78-85页

作者： ZHANG Yang , XU Hong-kun, CHANG Yong-yu, YANG da-cheng, WANG Ya-feng School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Bi-dimensional Markov chain model based on cooperative medium access control （MAC） of wireless local area networks （WLAN） is considered to reflect system performance accurately. Two basic factors that affect the analysis results are station retry limits and non-saturated transmit probability. A uniform solution considering both factors is proposed. To prove the theoretical analysis, a cooperative MAC （CoopMAC） topology is established and the simulation model is enhanced by changing the cooperative table to the nodes＇ memory with more information added. Meanwhile, the three-way handshake scheme is modified and a handshake threshold is set based on the packet size. Simulation results show the performance analytical model is accurate, and the rate-adaptive cooperative MAC protocol significantly improves the network performance in terms of non-saturated system throughput and delay.

关键词： performance analysis cooperative MAC bi-dimensional Markov Chain non-saturated transmit station retry limit

Quantum phase transition of the Jaynes-Cummings model

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 1-9页

作者： cheng Liu Jin-feng Huang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesHunan Normal UniversityChangsha 410081China

Herein,we propose an experimentally feasible scheme to show the quantum phase transition of the Jaynes-Cummings(JC)model by modulating the transition frequency of a two-level system in a quantum Rabi model with strong *** tuning the modulation frequency and amplitude,the ratio of the effective coupling strength of the rotating terms to the effective cavity(atomic transition)frequency can enter the deep-strong coupling regime,while the counter-rotating terms can be ***,a deep-strong JC model is *** ratio of the coupling strength to resonance frequencies in the deep-strong JC model is two orders of magnitude larger than the corresponding ratio in the original quantum Rabi *** scheme can be employed in atom-cavity resonance and off-resonance cases,and it is valid over a broad *** nonzero average cavity photons of the ground state indicate the emergence of a quantum phase ***,we demonstrate the dependence of the phase diagram on the atom-cavity detuning and modulation *** the parameters used in our scheme are within the reach of current experimental *** scheme provides a new mechanism for investigating the critical phenomena of finite-sized systems without requiring classical field limits,thereby opening a door for studying fundamental quantum phenomena occurring in the ultrastrong and even deep-strong coupling regimes.

关键词： Jaynes-Cummings model quantum phase transition frequency modulation