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Ultrahigh lithiation dynamics of Li_(4)Ti_(5)O_(12)as an anode material with open diffusion channels induced by chemical presodiation

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Rare Metals 2023年第2期42卷 471-483页

作者： yong-hui zhang Zhou-Huan Nie Chen-Qiang Du Ji-Wei zhang Jing-Wei zhang National and Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng475004China Collaborative Innovation Center of Nano Functional Materials and Applications of Henan Province Henan UniversityKaifeng475004China

Spinel lithium titanate(Li_(4)Ti_(5)O_(12),LTO),with the merits of safety operation voltage,stable crystal structure,and minor lattice volume changes,becomes an optimal anode material for high-power Li-ion ***,the inherent wide bandgap and low lithiation reactivity of Li_(4)Ti_(5)O_(12)bring about poor conductivity and lithiation dynamics,limiting its further ***,we design and prepare unique Li_(4)Ti_(5)O_(12)anode materials with extremely low dopant content of Na^(+)utilizing the amorphous *** resultant Li_(4)Na_(0.008-)Ti_(5)O_(12.004)sample(denoted as NLTO-0.008)presents superior rate performances and cycle ability,with a reversible capacity of 149.4 mAh·g^(-1)at the current rate ***-0.008 retains the charge capacity of151.3 mAh·g^(-1)with a capacity loss of 0.5%after 1000cycles at the current rate of 1.0C(charge)/10.0C(discharge).The kinetic studies furtherly demonstrate that the lithiation reaction energy and diffusion energy barrier decrease by 28.8%and 30%,*** structure analysis indicates that Na^(+)occupies the 16d Li site and forms distorted LiO_(4)tetrahedron and TiO_(6)*** lattice distortion forms open diffusion channels,thus enhancing the Li^(+)diffusion dynamics and decreasing the lithiation reaction energy barrier for Li_(4)Ti_(5)O_(12).Therefore,the pre-sodiation strategy may arouse great interest in understanding and developing intercalation-type transitionmetal-based electrode materials in high-power lithium-ion batteries.

关键词： Lithium-ion batteries(LIBs) Anode material Lithium titanate Crystal structure Electrochemical performances

A new hopane triterpenoid from Saxiglossum angustissimum

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Chinese Chemical Letters 2008年第7期19卷 835-836页

作者： hui Fang Pi Zhi Hong Zhong Han Li Ruan Peng zhang yong hui zhang Ji Zhou Wu Faculty of Pharmaceutical Sciences Tongji Medical College of Huazhong University of Science and Technology Wuhan 430030 PR China

A new hopane triterpenoid, hopane 22, 29-diol-29-formate （1）, has been isolated from the whole herbs of Saxiglossum angustissimum （Cries.） Ching and its structure has been successfully determined on the basis of s... 详细信息

关键词： Saxiglossum angustissimum Hopane Hopane-22 29-Diol-29-formate

A new alkaloid from Lycoris aurea

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Chinese Chemical Letters 2009年第11期20卷 1319-1320页

作者： hui Fang Pi Peng zhang Han Li Ruan yong hui zhang Han Dong Sun Ji Zhou Wu Faculty of Pharmaceutical Sciences Tongji Medical College of Huazhong University of Science and Technology Hubei Key Laboratory of Natural Medicinal Chemistry and Resources Evaluation Wuhan 430030 China

A new alkaloid was isolated from the bulbs of Lycoris aurea （L＇Herit.） Herb. Its structure was established as 3-o-ethyltazettinol through chemical and spectroscopic studies including 2D NMR.

关键词： Lycoris aurea 3-o-Ethyltazettinol

Theoretical study of the hyperfine interaction constants, Landé g-factors, and electric quadrupole moments for the low-lying states of the 61Niq+(q=11,12,14,and 15) ions

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Chinese Physics B 2021年第1期30卷 65-72页

作者： Ting-Xian zhang yong-hui zhang Cheng-Bin Li Ting-Yun Shi State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

Highly charged nickel ions have been suggested as candidates for the ultra-precise optical clock, meanwhile the relevant experiment has been carried out. In the framework of the multiconfiguration Dirac–Hartree–Fock(MCDHF)method, we calculated the hyperfine interaction constants, the Landég-factors, and the electric quadrupole moments for the low-lying states in the 61Ni11+,61Ni12+,61Ni14+, and61Ni15+ ions. These states are clock states of the selected clock transitions in highly charged nickel ions(see Fig. 1). Based on discussing the effects of the electron correlations, the Breit interaction, and quantum electrodynamics(QED) effect on these physical quantities, reasonable uncertainties were obtained for our calculated results. In addition, the electric quadrupole frequency shifts and the Zeeman frequency shifts of the clock transitions concerned were analyzed.

关键词： hyperfine interaction Landég-factors electric quadrupole moment multiconfiguration Dirac-Hartree–Fock(MCDHF)method

Hyperpolarizabilities of alkaline-earth metal ions Be^+, Mg^+, and Ca^+

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Science China(Physics,Mechanics & Astronomy) 2016年第9期59卷 33-38页

作者： Dong Yin yong-hui zhang Cheng-Bin Li Ke-Lin Gao Ting-Yun Shi State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of SciencesWuhan 430071China Graduate University of the Chinese Academy of Sciences Beijing 100049China Department of Physics Henan Normal UniversityXinxiang 453007China Key Laboratory of Atomic Frequency Standards Wuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

The knowledge of the hyperpolarizabilities of atoms and ions is helpful for the analysis of the high order effects of the frequency shifts in precision spectroscopy experiments. Liu et al. [Phys. Rev. Lett. 114, 223001 （2015）] proposed to establish all-optical trapped ion clocks using laser at the magic wavelength for clock transition. To evaluate the high-order frequency shifts in this new scheme of optical clocks, hyperpolarizabilities are needed, but absent. Using the finite field method based on the B-spline basis set and model potentials, we calculated the electric-field-dependent energy shifts of the ground and low-lying excited states in Be＋, Mg＋, and Ca＋ in the field strength range of 0.0-6×10-5 a.u.. The scalar and tensor polarizabilities （α0, α2） and hyperpolarizabilities （Y0,Y2, 74） were deduced. The results of the hyperpolarizabilities for Be＋ showed good agreement with the values in literature, implying that the present method can be applied for the effective estimation of the atomic hyperpolarizabilities, which are rarely reported but needed in experiments. The feasibility of optical trapping of Ca＋ is discussed, and the contributions of hyperpolarizabilities to the transition frequency shift for Ca＋ in the optical dipole trap are estimated using quasi-electrostatic approximation.

关键词： hyperpolarizability alkaline-earth metal ion finite field method

Study on parameters influencing analytical performance of laser-induced breakdown spectroscopy

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Frontiers of physics 2012年第6期7卷 714-720页

作者： yong zhang Yun-Hai Jia Jin-Wen Chen Xue-Jing Shen Lei Zhao Chun Yang yong-Yan Chen yong-hui zhang Peng-Cheng Han National Analysis Center for Iron and Steel Central Iron&Steel Research InstituteBeijing 100081China

Lens-to-sample distances, delay time, atmospheric condition, laser pulse energy, etc. had obvious effects on the analytical performance of laser-induced breakdown spectroscopy. In this paper, these parameters are investigated in greater detail and we will explain how they have influences on the analytical performance. The results show that the focal plane under the sample surface can improve precision and detection limit, and the delay time should be decided according to sensitivity and accuracy. Spectral line intensity is stronger in argon than helium, nitrogen and air gas environment. Pulse energy should exceed energy threshold （about 50 m J） which can generate plasma, and the energy should not exceed about 300 mJ to avoid plasma shielding. Under optimum parameters, concentration relative standard deviation of C, Si, Mn, P, S, Ni, and Cr for low-alloyed steel （sample number 11278） which were measured 11 times is 2.37%, 2.18%, 2.23%, 7.8%, 9.34%, 1.92%, and 2.13%, respectively. And the detection limit of C, Si, Mn, P, S, Ni, and Cr for pure steel is 0.0045%, 0.0072%, 0.0069%, 0.0027%, 0.0024%, 0.0047%, and 0.0024%, respectively.

关键词： laser-induced breakdown spectroscopy (LIBS) analytical performance plasma diagno- sis plasma shielding

A new cycloartane triterpenoid from the leaves and stems of Fritillaria hupehensis

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Chinese Chemical Letters 2007年第4期18卷 418-420页

作者： hui Fang Pi Peng zhang Tian Zhu Han Li Ruan yong hui zhang Han Dong Sun Ji Zhou Wu Faculty of Pharmaceutical Sciences Tongji Medical College of Huazhong University of Science and Technology Wuhan 430030 China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botany Kunming 650204 China

A new triterpenoid has been isolated from the leaves and stems of Fritillaria hupehensis Hsiao et K.C. Hsia. Its structure was established as （2329-9,19-cycloart-23-ene-3α,25-diol 1 through chemical and spectroscopi... 详细信息

关键词： Fritillaria hupehensis Cycloartane triterpenoids (23Z)-9,19-Cycloart-23-ene-3α,25-diol

VISCOSITY EFFECTS ON THE BEHAVIOR OF A RISING BUBBLE

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Journal of Hydrodynamics 2010年第1期22卷 81-89页

作者： WANG Han zhang Zhen-yu YANG yong-ming zhang hui-sheng Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China Department of Mathematics Shanghai University of Finance and Economics Shanghai 200433 China

In the incompressible fluid flow regime, without taking consideration of surface tension effects, the viscosity effects on the behavior of an initially spherical buoyancy-driven bubble rising in an infinite and initially stationary liquid are investigated numerically by the Volume Of Fluid （VOF） method. The ratio of the gas density to the liquid density is taken as 0.001, and the gas viscosity to the liquid viscosity is 0.01, which is close to the case of an air bubble rising in water. It is found by numerical experiments that there exist two critical Reynolds numbers Re1 and Re2 , which are in between 30 and 50 and in between 10 and 20, respectively. As Re 〉 Re1 the bubble will have the transition to toroidal form, and the toroidal bubble will break down into two toroidal bubbles. In this case viscosity will damp the development of the liquid jet and delay the formation of the toroidal bubble. As Re〈Re1 the transition will not happen. As Re2 〈 Re 〈 Re1, the bubble will split from its rim into a toroidal bubble and a spherical cap-like bubble, and as Re〈Re2 the splitting will not occur and the bubble can finally reach a stationary shape. With the decrease of the Reynolds number, the stationary shape changes from spherical-cap bubble with skirt to dimpled peach-like bubble. Before the bubble reaches its stationary shape the vortex structure in the flow field varies with time. The vortex structure corresponding to bubble stationary shape varies with the Reynolds number. It is also found that there exists another critical Reynolds number Re^＊ which is in between Re1 and Re2 , and as Re 〈 Re^＊, after the bubble rises in an accelerating manner for a moment, it will rise with an almost constant speed, and the speed increases with increasing Reynolds number. As Re 〉 Re^＊, it will not rise with a constant speed. The mechanism of the above phenomena has been analyzed theoretically and numerically.

关键词： rising bubble viscosity effects buoyancy force Volume Of Fluid (VOF) method

SURFACE TENSION EFFECTS ON THE BEHAVIOR OF TWO RISING BUBBLES

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Journal of Hydrodynamics 2011年第2期23卷 135-144页

作者： WANG Han zhang Zhen-yu YANG yong-ming zhang hui-sheng State Nuclear Power Technology Corporation Research and Development Centre SNPTRD Beijing 100190 China Department of Mathematics Shanghai University of Finance and Economics Shanghai 200433 China Department of Mechanics and Engineering Science Fudan University Shanghai 200433 China

In the inviscid and incompressible fluid flow regime, surface tension effects on the behavior of two initially spherical bubbles with same size rising axisymmetrically in an infinite and initially stationary liquid are investigated numerically with the VOF method. The numerical experiments are performed for two bubbles with two different bubble distances. The ratio of gas density to liquid density is 0.001, which is close to the case of air bubbles rising in water. In the case of Dis = 2.5, where Dis is defined as the ratio of the distance between the bubble centroids to the radius of the bubble, it is found from numerical experiments that there exist four critical Weber numbers We1 , We2 , We3 and We4 , which are in between 10 and 100, 3 and 4, 1.5 and 1.8, and 0.2 and 0.3, respectively. In the case of Dis = 2.3, similar phenomena also appear but the corresponding four critical Weber numbers are lower than those in the case of Dis = 2.5. The mechanism of the above phenomena is analyzed theoretically and numerically.

关键词： two bubbles buoyancy surface tension VOF method