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A detailed study on stereodynamics of He+H_2^(+)(v=1,j=1) reaction with quasi-classical trajectory calculations

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Science China(Physics,Mechanics & Astronomy) 2012年第3期55卷 436-442页

作者： LIU XinGuo ZHAO LianQing zhang qinggang School of Physics and Electronics Shandong Normal UniversityJinan 250014China

Calculations of He+H2+ (v=l,j=l) reaction system are carded out on a new potential energy surface (PES) at different collision energies with the quasi-classical trajectory (QCT) method. The results of the reaction probability and the cross section curves show an obvious oscillatory structure attributed to the resonances caused by the potential well of the Hell2+ complex. The three angular distributions P(θr), P(φr) and P(θr,(φr) as well as four polarization dependent differential cross sections (PDDCSs) are calculated, respectively. Results indicate that the collision energy has great influence on both the vector correlation of k-k', k-j', k-k'-j' and the PDDCSs of the title reaction. The rotational polarization of product Hell+ presents diverse characteristics at dif- ferent collision energies. The rotational angular momentum vectorsj' of product are both aligned and oriented. Furthermore, the product Hell+ tends to scatter forward correspondingly as the collision energy increases.

关键词： QCT PDDCS vector correlation rotational polarization

Semirigid vibrating rotor target calculation for reaction O(^(3)P)+CH_(4)→CH_(3)+OH

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Science China(Physics,Mechanics & Astronomy) 2004年第2期47卷 223-230页

作者： LIU Xinguo BAI Lihua zhang qinggang Department of Physics Shandong Normal University Jinan 250014 China Department of Physics Shandong Normal University Jinan 250014 China Department of Physics Shandong Normal University Jinan 250014 China

The time-dependent quantum dynamics calculation for reaction O(3P)+CH4 →CH3+OH is made, using of the semirigid vibrating rotor target (SVRT) model and the time-dependent wave packet (TDWP) method. The corresponding reaction probabilities of different initial states are provided. From the calculation of initial rovibrational statej=0,v=0, 1, we can see that the excitation of the H-CH3 stretching vibration gives significant enhancement of reaction probability and the reaction threshold decreases dramatically with the enhancement of the vibrating excitation, which indicates that the vibrating energy of reagent molecules contributes a lot to the molecular collision. As for the calculation of reaction probability of statev=0,j=0,1,2,3, the results show that the reaction probability rises significantly with the enhancement of rotational quantum numberj while the reaction threshold has no changes. The spatial steric effect of the title reaction is studied and analyzed too after the calculation of reaction probability of statesj=5,k=0–2,n=0 andj=5,k=2,n=0–2 is made.

关键词： SVRT model, time-dependent wave packet, reaction probability, steric effect.

Time-dependent wave packet approach to the pulse delay effect upon RbI photoelectron spectrum

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Science China Chemistry 2006年第3期49卷 214-218页

作者： LIU Chunhua MENG Qingtian zhang qinggang College of Physics and Electronics Shandong Normal University Jinan 250014 China College of Physics and Electronics Shandong Normal University Jinan 250014 China College of Physics and Electronics Shandong Normal University Jinan 250014 China

The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulatedusing the time-dependent wave-packet method. Both the normal three-photon ionization process andauto-ionization process are involved in the simulation. The calculated results show that the changeof delay time will influence the shape of the photoelectron spectrum (PES), and the influence issubstantially due to the existence of the crossing between excited states and the strong laser fieldwhich will change the position of relevant curves.

关键词： time-dependent wave packet method, multiphoton ionization (MPI), time-resolved photoelectron spectrum (TRPES), auto-ionization.

The Establishment and Analysis of the Structural-Electromagnetic Coupling Model of the Electrostatically Controlled Deployable Membrane Antenna

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Chinese Journal of Electronics 2024年第2期33卷 479-487页

作者： Shunji zhang Yongzhen GU Wang ZHONG qinggang zhang Qingdao University of Science and Technology Key Laboratory of Electronic Equipment Structure Design of Ministry of Education Xidian University

A new structural-electromagnetic coupling(SEC) analysis based on quadratic elements is proposed to solve the mismatch problem between structural elements and electromagnetic grids of the electrostatically controlled deployable membrane antenna(ECDMA). Firstly, the ECDMA reflector surface is meshed and redefined by a series of quadratic elements. Without grid transformation, the calculating formulas for the far-field pattern of ECDMA are derived by the physical-optics method. Then the structural deformation of ECDMA is analyzed and the far-field pattern calculating formulas including deformation errors are developed. Simulation and experiment results show that the quadratic elements are effective and efficient in SEC analysis of the ECDMA, moreover, the electromagnetic grid size demand and the grid discretization error are reduced greatly.

关键词： Couplings Electrodes Analytical models Deformation Electromagnetic fields Electromagnetics Optimization

Folding of EK peptide and its dependence on salt concentration and pH: A computational study

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Science China Chemistry 2011年第12期54卷 1974-1981页

作者： MEI Ye zhang DaWei DUAN Li zhang qinggang zhang John ZengHui State Key Laboratory of Precision Spectroscopy East China Normal University Shanghai 200062 China Institute of Theoretical and Computational Science East China Normal University Shanghai 200062 China Division of Chemistry and Biological Chemistry School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore College of Physics and Electronics Shandong Normal University Jinan 250014 China Department of Chemistry New York University New York 10003 USA

In this study, we apply both palrwise AMBER03 force field and the recently developed polarized force field to study the folding process of EK peptide under various ion strength and pH conditions. The polarized force field is based on our newly proposed adaptive hydrogen bond-specific charge （AHBC） scheme. These two force fields differ only by the atomic charges. Solvent effect is described with generalized Born models （IGB5 in AMBER 10 package）. The result shows that although when applying AMBER03 charge, the helical structure is preferred, its dependence on salt concentration and pH is qualitatively wrong. While using AHBC the peptide finds its native structure within 10 ns, and then fluctuates around this folded state. Under high salt concentration or extreme pH conditions the calculated helical structure probability drops, which is in qualitative agreement with the experiment. Analysis of the atomic charges and the interaction between the donor-acceptor pair in main hydrogen bonds shows that the helical structure is stabilized when polarization effect is counted. It again shows that polarization effect is a very important improvement over traditional force field and is essential for protein folding. We also prove that the salt bridge interaction between 4-residue apart GLU and LYS residues is not critical to the stability of helical structure of EK peptide, but is merely an auxiliary factor, also in agreement with the experiment.

关键词： EK peptide polarization salt concentration pH

The Choice of Mesh Size and Integration Points Number for the Electrostatically Controlled Membrane Antenna Structural-Electromagnetic Coupling Model

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Chinese Journal of Electronics 2024年第2期33卷 443-448页

作者： Yongzhen GU qinggang zhang Xiao YU Guixu LI Qingdao University of Science and Technology

It is of great significance for the improvement of the computational efficiency of the electrostatically controlled membrane antenna(ECMA) structural-electromagnetic coupling model through the choice of appropriate mesh size and integration points number. In this paper, the physical optics formulation is used to analyze the radiation pattern of the ECMA surface, and the finite element method is applied to the electrostatic-structural coupling analysis. An expression for the relation between the mesh size, the focal length of the parabolic antenna, and the wavelength is developed based on the discretization error analysis of the triangular mesh approximating the parabolic surface. Moreover, the integration points number in each triangular mesh is determined by the numerical evaluation of the physical optics integral. Numerical results show that the proposed method improves the computing efficiency by about 87% compared with the referenced method.

关键词： Couplings Surface waves Error analysis Computational modeling Physical optics Numerical models Finite element analysis

Synergetic effects of blended materials for Lithium-ion batteries

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Science China(Technological Sciences) 2016年第9期59卷 1370-1376页

作者： REN Heng GUO YanQun CHEN ZhenLian zhang XianHui zhang ZhiFeng LI YanTu zhang qinggang WU QingGuo LI Jun Department of Physics Shanghai University Shanghai 200444 China Ningbo Institute of Material Technology & Engineering Chinese Academy of Sciences Ningbo 315201 China Guangdong Keprime Enerstore Ltd Guangzhou 510530 China Zhejiang WELL Y Energy Corporation Cixi 315301 China

LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2, LiMn_2O_4 and LiCoO_2 are paired to make the blended materials for the cathode of lithium-ion batteries. The factors impacting on the characteristics of blended materials are studied using constant current charge/discharge measurement and electrochemical impedance spectroscopy. The results show that the three pairs of blended materials exhibit very different synergetic effects in high C-rate discharging. The mechanism of particle synergetic effect has a physical root on the compensating material property of blending components, which fundamentally correlates with their similarity and difference in crystalline and electronic structures. The AC impedance show the obvious changes that alternate the high C-rate performance, due to reduced particle impedance in blended materials. The pairs of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2-LiMn_2O and LiCoO_2-LiMn_2O_4 present obvious increases in high C-rate reversible capacities than does the pair LiCoO_2-LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2.

关键词： blended cathode materials synergetic surplus rate performance electrochemical impedance spectroscopy

Stabilizing perovskite nanocrystals by controlling protective surface ligands density

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Nano Research 2019年第6期12卷 1461-1465页

作者： Weilin Zheng Zhichun Li Congyang zhang Bo Wang qinggang zhang Qun Wan Long Kong Liang Li School of Environmental Science and Engineering Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

After nanocrystals synthesis,the purification process with anti-solvents is an essential step to get clean nanocrystals,which could get rid of the by-products of the *** is generally recognized that this process could bring a positive effect for the afterward optoelectronic ***,we found that the optical properties and photostability of perovskite CsPbBr3 nanocrystals were unavoidably deteriorated after they were washed with anti-solvents,and this deterioration is strongly related to the decreasing of surface ligands ***,in this paper,we tried to purposely not wash the CsPbBr3 nanocrystals solution after adding didodecyl dimethylammonium bromide (DDAB),and found the existing of DDAB in solution could result in a dramatically enhanced *** by these results,we proposed a new strategy to stabilize perovskite nanocrystals from the view of packaging process:adding protective ligands into the perovskite nanocrystals resin directly,then encapsulating them on blue light-emitting diodes (LED) ***,stable LED devices (20 mA,2.7V) were achieved by this way,which can keep 80% of the initial photoluminescence (PL) intensity for more than 50 h,while the devices with CsPbBr3 nanocrystals without adding protective ligands into resin dropped to 50% of their initial PL intensity within 6 *** approach offers a new thought to stabilize perovskite nanocrystals as down-conversion phosphor in quantum dots liquid crystal display.

关键词： perovskite nanocrystals purification ligand density photostability encapsulation strategy

Synthesis and Electrochemical Properties of FeSbO_4 Nanorods

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Wuhan University Journal of Natural Sciences 2013年第3期18卷 185-190页

作者： zhang qinggang HU Xiaohong ZHAN Dan ZHU Guozhu PENG Tianyou College of Chemistry and Molecular Science Wuhan University

Well-crystallized FeSbO 4 nanorods with rutile-like structure are synthesized through a solid-state reaction and used as cathode material of Li-ion battery for the first *** obtained nanorods can react with 11 Li-ions per FeSbO 4 unit with a specific discharge capacity of 1 100 1 mAh g between 0.1 and 2.0 *** discharge plateaus can be observed during the fully discharging process,but the reversible reaction with 1 Li occurs between 1.5 V and 4.5 V *** ＋ /Li,and the reversible capacity is only 50-80 1 mAh *** 4 nanorods have a stable cyclic performance between 1.5 V and 4.5 V and it can be used as cathode material for rechargeable Li-ion battery.

关键词： iron antimonate lithium battery nanorod electrochemical reaction cathode material