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Enhancing electrochemical capacity and interfacial stability of lithium-ion batteries through side reaction modulation with ultrathin carbon nanotube film and optimized lithium cobalt oxide particle size

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Nano Research 2024年第8期17卷 7230-7241页

作者： Wei xi xiaogang xia Jiacheng Zhu Dehua Yang Sishen xie Beijing National Laboratory for Condensed Matter physics and institute of physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Advanced Passivation Technology Lab College of Physics Science and TechnologyHebei UniversityBaoding 071002China

Lithium cobalt oxide(LCO),the first commercialized cathode active material for lithium-ion batteries,is known for high voltage and ***,its application has been limited by relatively low capacity and stability at high *** particle size is considered one of the most straightforward and effective strategies to enhance ion transfer,thus increasing the rate ***,side reactions are simultaneously enhanced as the specific surface area ***,we investigate the impact of LCO particles with varying size distributions and optimize the particle *** modulate the side reactions associated with particle size reduction,an ultrathin carbon nanotube film(UCNF)is introduced to coat the cathode *** this simple process and optimized particle size,the rate performance improves significantly,normal commercial LCO achieves 118 mA·h·g^(−1)at 3.0–4.3 V and 20 C(0.72 mA·h·cm^(−2)),corresponding to power density of 8732 W·kg^(−1).This method is applied to high voltage as well,152 mA·h·g^(−1)at 3.0–4.6 V and 20 C(0.99 mA·h·cm^(−2))was achieved with high-voltage LCO(HVLCO),corresponding to power density of 11,552 W·kg^(−1).The cycling stability is also enhanced,with the capacity retention maintaining more than 96%after 100 cycles at 0.1 *** the first time,UCNF is demonstrated to suppress the excessive decomposition of the electrolytes and solvents by blocking electron injection/extraction between LCO and electrolyte *** findings provide a simple method for improving LCO rate performance,especially at high C-rates.

关键词： lithium-ion batteries lithium cobalt oxides carbon nanomaterials side reactions

SYNTHESIS AND OPTICAL PROPERTIES OF A NOVEL ORGANIC/INORGANIC HYBRID NONLINEAR OPTICAL POLYMER VIA SOL-GEL PROCESS

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Chinese Journal of Polymer Science 2001年第4期19卷 421-427页

作者： Hong-xia xi Zhong Li Zhao-xi Liang The institute of Chemical Engineering South china university Guangzhou 510640 china The institute of Polymer Science, Zhongshan university Guangzhou 510275, china S china Univ Inst Chem Engn Canton 510640 Peoples R China Zhongshan Univ Inst Polymer Sci Canton 510275 Peoples R China

A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4 ' -hydroxy azobenzene was covalently bonded to the triethoxysilane derivative, i.e, gamma -isocyanatopropyl triethoxysilane. The preparation process and properties of the sol-gel derived NLO polymer were studied and characterized by SEM, FTIR,H-1-NMR, UV-Vis, DSC and second harmonic generation (SHG) measurement. The results indicated that the chemical bonding of the chromophores to the inorganic SiO2 networks induces low dipole alignment relaxation and preferable orientational stability. The SHG measurements also showed that the bonded polymer film containing 75 wt% of the akoxysilane dye has a high electro-optic coefficient (r(33)) of 7.1 pm/V at 1.1 mum wavelength, and exhibit good SHG stability, the r(33) values can maintain about 92.7% of its initial value at room temperature for 90 days, and can maintain about 59.3% at 100 degreesC for 300 min.

关键词： sol-gel process nonlinear optical material alkoxysilane dye dipole alignment relaxation chromophore

Light A physics in the lepton-specific two-Higgs doublet model

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1981-1987页

作者： CAO JunJie 1,HENG Zhaoxia 2,3 & WAN PeiHua 1 1 College of physics & Information Engineering,Henan Normal university,xinxiang 453007,china 2 Key Laboratory of Frontiers in Theoretical physics,institute of Theoretical physics,Chinese Academy of Sciences,Beijing 100190,china 3 Kavli institute for Theoretical physics china,Chinese Academy of Sciences,Beijing 100190,china 1. College of physics & Information Engineering Henan Normal University Xinxiang 453007 China2. Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China3. Kavli Institute for Theoretical Physics China Chinese Academy of Sciences Beijing 100190 China

We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and discuss its phenomenology at colliders in the allowed parameter *** constraints we consider come from the precision electroweak data,the direct search for Higgs boson,the muon anomalous magnetic moment,as well as some theoretical consistency *** find that in the allowed parameter space the CP-odd Higgs boson A is rather light (m A 30 GeV with 95% possibility),which is composed dominantly by the leptonic Higgs and decays dominantly into τ + τ;while the SM-like Higgs boson h (responsible largely for electroweak symmetry breaking) decays dominantly in the mode h → AA → 4τ with a large decay width,which will make the Higgs discovery more difficult at the ***,this scenario predicts rare Z decays Z → AAA and Z →τ + τA with their branching ratios ranging from 10-8 to 10-and 10-5 to 10-4 respectively,which may be accessible at the GigaZ option of the ILC.

关键词： Lepton-specific two-Higgs doublt model light Higgs boson A Z decays

A computational investigation of boron-doped chromium and chromium clusters by density functional theory

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Science china(physics,Mechanics & Astronomy) 2010年第5期53卷 812-817页

作者： GE Guixian1,JING Qun1 & LUO YouHua2,3 1 Key Laboratory of Ecophysics and Department of physics,Normal College,Shihezi university,xinjiang 832003,china 2 School of Science,East china university of Science and Technology,Shanghai 200237,china 3 institute of Theoretical physics,School of physics and Information Optoelectronics,Henan university,Kaifeng 475004,china 1. Key Laboratory of Ecophysics and Department of physics Normal College Shihezi University Xinjiang 832003 China2. School of Science East China University of Science and Technology Shanghai 200237 China3. Institute of Theoretical Physics School of Physics and Information Optoelectronics Henan University Kaifeng 475004 China

The geometries,stabilities and electronic properties of Crn and CrnB(n=2-9) clusters have been systematically investigated by density functional *** results suggest that the lowest energy structures for CrnB clusters can be obtained by substituting one Cr atom in Crn+1 clusters with B *** geometries of CrnB clusters are similar to that of Crn+1 clusters except for local structural *** second-order difference and fragmentation energy show Cr4,Cr6,Cr8,Cr3B,Cr5B and Cr8B cluster are the most stable among these studied *** impurity B increases the stabilities of chromium *** B is doped on the Crn clusters,cluster geometry does dominate positive role in enhancing their *** doped B atom does not change the coupling way of the Cr site in Crn clusters,but breaks the symmetry and the Cr atoms are no longer *** doped B atom increases the total magnetic moments of Crn in most cases.

关键词： Crn and CrnB clusters geometries electronic properties

Density functional theory study on the structural and electronic properties of Ag-adsorbed (MgO)_n clusters

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Science china(physics,Mechanics & Astronomy) 2009年第5期52卷 734-741页

作者： GE Guixian1, JING Qun1 & LUO YouHua2,3 1 Key Laboratory of Ecophysics and Department of physics, Normal College, Shihezi university, Shihezi 832003, china 2 School of Science, East china university of Science and Technology, Shanghai 200237, china 3 institute for Theoretical physics, Henan university, Kaifeng 475004, china Key Laboratory of Ecophysics and Department of physics Normal College Shihezi University Shihezi 832003 China School of Science East China University of Science and Technology Shanghai 200237 China institute for Theoretical physics Henan University Kaifeng 475004 China

Equilibrium geometries, charge distributions, stabilities and electronic properties of the Ag-adsorbed (MgO)n (n = 1-8) clusters have been investigated by density functional theory (DFT) with generalized gradient approximation (GGA) for exchange-correlation functional. The results show that hollow site is energetically preferred for n≥4, and the incoming Ag atoms tend to cluster on the existing Ag cluster. The Mulliken populations indicate that the interaction between the Ag atom and Magnesia clusters is mainly induced by a weak atomic polarization. The adsorbed Ag atom only causes charge redistributions of the atoms near itself. The effect of the adsorbed Ag atom on the bonding natures and structural features of Magnesia clusters is minor. Furthermore, the investigations on the first energy difference, fragmentation energies and electron affinities show that the Ag(MgO)4 and Ag(MgO)6 are the most stable among studied clusters.

关键词： Ag (MgO)_n clusters geometries electronic properties

Investigation into the rotational bands of ^(185)Pt with the particle-rotor model

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 114-118页

作者： LI GuangShun1,2, ZHOU xiaoHong1,2, ZHANG ShuangQuan3, ZHANG YuHu1 & MENG Jie3 1 institute of modern physics, Chinese Academy of Sciences, Lanzhou 730000, china 2 Graduate university of Chinese Academy of Sciences, Beijing 100049, china 3 School of physics and SK Laboratory of Nuclear physics & Technology, Peking university, Beijing 100871, china 1. institute of modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. Graduate university of Chinese Academy of Sciences Beijing 100049 China 3. School of physics and SK Laboratory of Nuclear physics & Technology Peking University Beijing 100871 China

Theoretical calculations have been performed for the ν9/2+[624](i13/2) and ν7/2-[503](f7/2) bands of 185Pt in the framework of particle-rotor model. The band properties of signature splitting and configuration mixing have been analyzed. The level energy and signature splitting before the band crossing can be well interpreted by introducing triaxiality. The positive-parity yrast band is pro posed to be dominated by the ν9/2+[624](i13/2) component, while the negative-parity band shows strong mixing of ν7/2-[503](f7/2) and ν9/2-[505](h9/2) configurations.

关键词： High-spin states particle-rotor model signature splitting configuration mixing

β-delayed proton decays near the proton drip line

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , xiE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2 , CHEN Yongshou 2 , XU Furong 3 , WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & xiNG Yebing 1 1. institute of modern physics, Chinese Academy of Sciences, Lanzhou 730000, china 2. Nuclear physics Department, china institute of Atomic Energy, Beijing 102413, china 3. Department of Technical physics, Peking university, Beijing 100871, china 4. Shanghai institute for Nuclear Research, Shanghai 201800, china 1. institute of modern physics Chinese Academy of Sciences 730000 Lanzhou China 2. Nuclear physics Department China Institute of Atomic Energy 102413 Beijing China 3. Department of Technical physics Peking University 100871 Beijing China 4. Shanghai institute for Nuclear Research 201800 Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2004, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92Rh as well as the predicted “waiting point” nuclei 89Ru and 93Pd are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2) The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142Ho and 128Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3) The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

Unlocking the potential of transdermal drug delivery

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International Journal of Smart and Nano Materials 2024年第3期15卷 432-468页

作者： Shuang Li Jianhao Wu xiangjun Peng xi-Qiao Feng institute of Biomechanics and Medical Engineering Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijingChina

Transdermal drug delivery(TDD)has gained clinical approval over several decades,with extensive research dedicated to novel drug and device *** notable research progress,the mar-ket adoption of TDD devices has not met anticipated levels,with oral administration and injection remaining predominant delivery *** maximize the potential of TDD,we identify bottlenecks hinder-ing its widespread clinical application and propose promising research *** begin by analyzing stringent demands necessary to truly benefit patients,addressing significant challenges in biomechanics,nanomedicine,and flexible ***,we delve into skin anatomy,enhancement strategies,nano-carriers,and their under-lining mechanisms,highlighting the importance and framework of quantitative *** on these discussions,we highlight the core strength of TDD,such as automatic precise administration based on feedback and high delivery efficiencies,especially applicable to localized conditions(e.g.,central nervous system diseases,tumors).Finally,we envision the future of intelligent TDD device and its opera-tion scenario,aiming to steer research efforts toward faster translation of laboratory innovations into widely used products for sufferers.

关键词： Transdermal drug delivery biomechanics nanomedicine flexible electronics

Coupled Cross-Flow/in-Line Vortex-Induced Vibration Responses of a Catenary-Type Riser Subjected to Uniform Flows

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Journal of Ocean university of china 2024年第5期23卷 1202-1212页

作者： LI xiaomin CAO xi LI Fuheng YANG Zhiwen College of Engineering Ocean University of ChinaQingdao 266404China College of Hydrodynamic Engineering Tianjin Research Institute for Water Transport EngineeringM.O.TTianjin 300456China

A three-dimensional numerical scheme was developed to investigate the vortex-induced vibration(VIV)of a catenary-type riser(CTR)in the in-line(IL)and cross-flow(CF)*** using the vector form intrinsic finite element method,the CTR was discretized into a finite number of spatial particles whose motions satisfy Newton’s second *** Van der Pol oscillator was used to simulate the effect of vortex *** coupling equations of structural vibration and wake oscillator were solved using an explicit central differential *** numerical model was verified with the published *** VIV characteristics of the CTR subjected to uniform flows,including displacement,frequency,standing wave,traveling wave,motion trajectory,and energy transfer,were studied *** numerical results revealed that the multimode property occurs in the CF-and IL-direction VIV responses of the *** increase in the flow velocity has slight effects on the maximum VIV *** to structural nonlin-earity,the double-frequency relationship in the CF and IL directions is rarely ***,the vibration trajectories display the shape of an inclined elliptical ***,the negative energy region is inconspicuous under the excitation of the uniform flow.

关键词： vortex-induced vibration vector form intrinsic finite element catenary-type riser wake oscillator equation