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Integrated multi-scale approach combining global homogenization and local refinement for multi-field analysis of high-temperature superconducting composite magnets

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 747-762页

作者： Hanxiao GUO Peifeng GAO Xingzhe WANG Key Laboratory of Mechanics on Western Disaster and Environment of Ministry of Education Key Laboratory of Special Function Materials and Structure Design of Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting applications.With respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic fields.Traditional numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally demanding.Herein,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake coils.This approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic scale.We then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic scale.The results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and efficient.The proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.

关键词： epoxy-impregnated high-temperature superconducting(HTS)magnet multi-scale method global homogenization(GH) local refinement(LR) multi-field analysis

Transcatheter aortic valve replacement: A journey of two decades and beyond

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中华医学杂志(英文版) 2024年第9期137卷 1012-1015页

作者： Xiong Tianyuan Chen Mao Department of Cardiology West China Hospital Sichuan University Chengdu Sichuan China Laboratory of Cardiac structure and function Institute of Cardiovascular Diseases West China Hospital Sichuan University Chengdu Sichuan China

The number of patients with calcific aortic stenosis (AS) is 9.4 million according to 2019 Global Disease Burden estimates,which will continue to increase as the population ages.For the treatment of symptomatic severe AS,transcatheter aortic valve replacement (TAVR) has evolved to be a well-established option across all risk spectra,with a rapid growth of procedures worldwide.The rise of TAVR initiates the revolution of the management of valvular heart diseases,from patient surveillance,the staging of disease,the use of multimodality imaging,the concept of the Heart Team,new designs and iterations of devices to technical innovations and the discovery of unmet clinical needs.As a consequence of the global adoption of TAVR,geographical differences in the epidemiology of AS and patient characteristics have also been further identified.An examination of the changing patient population,current applications and breakthroughs,and remaining challenges are crucial for the future of this technique.Herein,we discuss the temporal utilization of TAVR,the accumulation of evidence and progress of devices,the selection of patients,and some ongoing topics concerning the improvement of TAVR.

关键词： CEREBRAL EMBOLIC PROTECTION OUTCOMES TAVR

Co/N co-doped flower-like carbon-based phase change materials toward solar energy harvesting

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Aggregate 2024年第1期5卷 321-330页

作者： Xiao Chen Lei Wang Yan Gao Yang Li Xiaowei Zhang Yu Jiang Ge Wang Institute of Advanced Materials Beijing Normal UniversityBeijingChina Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory of Function Materials for Molecule and Structure ConstructionSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijingChina

The photothermal conversion capacity of pristine organic phase change materials(PCMs)is inherently insufficient in solar energy utilization.To upgrade their photothermal conversion capacity,we developed bimetallic zeolitic imidazolate framework(ZIF)derived Co/N co-doped flower-like carbon(Co/N-FLC)-based composite PCMs toward solar energy harvesting.3D interconnected carbon framework with low interfacial thermal resistance,abundant carbon defects and high content of nitrogen doping,excellent localized surface plasmon resonance(LSPR)effect of Co nanoparticles,and light absorber Co_(3)ZnC in Co/N-FLC synergistically upgrade the photothermal capacity of(polyethylene glycol)PEG@Co/N-FLC composite PCMs with an ultrahigh photothermal conversion efficiency of 94.8%under 0.16 W/cm^(2).Uniformly anchored Co and Co_(3)ZnC nanoparticles in carbon framework guarantee excellent photon capture ability.Bridging carbon nanotubes(CNTs)in 2D carbon nanosheets further accelerate the rapid transport of phonons by constructing cross-connected heat transfer paths.Additionally,PEG@Co/N-FLC exhibits a thermal energy storage density of 100.69 J/g and excellent thermal stability and durable reliability.Therefore,PEG@Co/N-FLC composite PCMs are promising candidates to accelerate the efficient utilization of solar energy.

关键词： bimetallic ZIF Co/N co-doped carbon phase change materials photothermal conversion thermal energy storage

Pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy for activating water and urea oxidation

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Green Energy & Environment 2024年第4期9卷 684-694页

作者： Guangfu Qian Wei Chen Jinli Chen Li Yong Gan Tianqi Yu Miaojing Pan Xiaoyan Zhuo Shibin Yin Guangxi Key Laboratory of Electrochemical Energy Materials College of Chemistry and Chemical EngineeringState Key Laboratory of Processing for Non-Ferrous Metal and Featured MaterialsGuangxi University100 Daxue RoadNanning530004China Institute for structure and function and Department of Physics Chongqing UniversityChongqing400030China

Exploitation of oxygen evolution reaction(OER)and urea oxidation reaction(UOR)catalysts with high activity and stability at large current density is a major challenge for energy-saving H_(2) production in water electrolysis.Herein,we use the pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy activated by NiFe_(2)O_(4)(FeNi/NiFe_(2)O_(4)@NC)for efficiently increasing the performance of water and urea oxidation.Due to the tensile strain effect on FeNi/NiFe_(2)O_(4)@NC,it provides a favorable modulation on the electronic properties of the active center,thus enabling amazing OER(η_(100)=196 mV)and UOR(E_(10)=1.32 V)intrinsic activity.Besides,the carbon-coated layers can be used as armor to prevent FeNi alloy from being corroded by the electrolyte for enhancing the OER/UOR stability at large current density,showing high industrial practicability.This work thus provides a simple way to prepare high-efficiency catalyst for activating water and urea oxidation.

关键词： Carbon-encapsulated Tensile strain Catalyst Oxygen evolution reaction Urea oxidation reaction

Phase transition of multi-component(TiZrVNb)C ceramics—Part II:From single phase to multiple phases via adjusting V content

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Journal of Advanced Ceramics 2024年第5期13卷 689-698页

作者： Qingyi Kong Lei Chen Sijia Huo Kunxuan Li Wenyu Lu Yujin Wang Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced structure‒function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

To address the relatively mediocre mechanical properties of single-phase multi-component carbide ceramics,a phase transition from a single phase to multiple phases was proposed to achieve superior mechanical properties.A series of(TiZrVxNb)C0.8 ceramics with different V contents were fabricated by spark plasma sintering(SPS).The influence of the V content on the phase composition,microstructural evolution,and mechanical properties was investigated in detail.The transition behavior from a single phase to multiple phases is discovered and discussed.The formation of the Zr-rich phase and Zr-poor phase can be attributed to the increase in lattice distortion and mixed enthalpy caused by the addition of V.A nanometer lamellar structure with a semi-coherent interface obtained via in situ decomposition is reported for the first time in multi-component carbide ceramics.The semi-coherent interfaces with high dislocation density and strain concentration effectively improve the mechanical properties,grain refinement,and multi-phase formation.The optimal comprehensive mechanical properties of the Vickers hardness(26.3 GPa),flexural strength(369 MPa),and fracture toughness(3.1 MPa·m1/2)were achieved for the sample with 20 mol%V.

关键词： multi-component ceramics multiple phases microstructure evolution phase decomposition mechanical properties

Potential role of hippocampal neurogenesis in spinal cord injury induced post-trauma depression

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Neural Regeneration Research 2024年第10期19卷 2144-2156页

作者： Ying Ma Yue Qiao Xiang Gao Spinal Cord and brain Injury Research group Stark Neuroscience Research InstituteIndianapolisINUSA Department of Neurological Surgery Indiana University School of MedicineIndianapolisINUSA Department of Neurology Shengjing Hospital of China Medical UniversityShenyangLiaoning ProvinceChina

It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a variety of secondary complications, including memory loss, cognitive decline, depression, and Alzheimer's disease. The largescale longitudinal population-based studies indicate that post-trauma depression is highly prevalent in spinal cord injury patients. Yet, few basic studies have been conducted to address the potential molecular mechanisms. One of possible factors underlying the depression is the reduction of adult hippocampal neurogenesis which may come from less physical activity, social isolation, chronic pain, and elevated neuroinflammation after spinal cord injury. However, there is no clear consensus yet. In this review, we will first summarize the alteration of hippocampal neurogenesis post-spinal cord injury. Then, we will discuss possible mechanisms underlie this important spinal cord injury consequence. Finally, we will outline the potential therapeutic options aimed at enhancing hippocampal neurogenesis to ameliorate depression.

关键词： antidepressants chronic pain depression exercise hippocampal neurogenesis inflammation inhibition neuroinflammation physical activity deficits social isolation spinal cord injury

Phase transition of multi-component(TiZrVNb)C ceramics—Part I:Phase decomposition induced by carbon content

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Journal of Advanced Ceramics 2024年第5期13卷 679-688页

作者： Qingyi Kong Rao Zhang Lei Chen Sijia Huo Wenyu Lu Yujin Wang Boxin Wei Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced structure‒function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150001China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

Phase decomposition can effectively enhance the mechanical properties of carbide ceramics and can overcome the difficulty of enhancing the mechanical properties of single-phase multicomponent carbide ceramics.In this work,a series of nonstoichiometric(TiZrVNb)Cx ceramics were prepared by spark plasma sintering(SPS)at different temperatures.The effects of the carbon content on the phase composition,microstructure evolution,and mechanical properties were investigated in detail.Phase decomposition occurred with decreasing carbon content.Two different solid solutions of(Ti,V)-rich and Zr-rich phases formed from the decomposition of equimolar single-phase solid solutions,namely,the Zr-poor phase and Zr-rich phase,respectively.The distribution of Nb element is relatively uniform.The semicoherent interfaces between the Zr-poor phase and the Zr-rich phase can harden and strengthen effectively under the synergistic effect of grain refinement.Ceramics with phase decomposition structures have apparent advantages compared to single-phase high-entropy carbides.This work provides an important train of thought for the microstructure tailoring and properties optimization of multi-component carbide ceramics.

关键词： multicomponent ceramics nontoichiometry microstructure evolution phase decomposition mechanical properties

An aqueous BiI_(3)-Zn battery with dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox

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Journal of Energy Chemistry 2024年第2期89卷 670-678,I0014页

作者： Qi Deng Fangzhong Liu Xiongwei Wu Changzhu Li Weibin Zhou Bei Long State Key Laboratory of Utilization of Woody Oil Resource Key Laboratory of National Forestry and Grassland Administration on Utilization Science for Southern Woody Oil ResourcesHunan Provincial Key Laboratory of Oils&Fats Molecular Structure and FunctionHunan Academy of ForestryChangsha 410004HunanChina School of Chemistry Xiangtan UniversityXiangtan 411105HunanChina School of Chemistry and Materials Science Hunan Agricultural UniversityChangsha 410128HunanChina

The development of aqueous battery with dual mechanisms is now arousing more and more interest.The dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox bring unexpected effects.Herein,differing from previous studies using Zn I_(2)additive,this work designs an aqueous Bi I_(3)-Zn battery with selfsupplied I^(-).Ex situ tests reveal the conversion of Bi I_(3)into Bi(discharge)and Bi OI(charge)at the 1st cycle and the dissolved I^(-)in electrolyte.The active I^(-)species enhances the specific capacity and discharge medium voltage of electrode as well as improves the generation of Zn dendrite and by-product.Furthermore,the porous hard carbon is introduced to enhance the electronic/ionic conductivity and adsorb iodine species,proven by experimental and theoretical studies.Accordingly,the well-designed Bi I_(3)-Zn battery delivers a high reversible capacity of 182 m A h g^(-1)at 0.2 A g^(-1),an excellent rate capability with 88 m A h g^(-1)at 10 A g^(-1),and an impressive cyclability with 63%capacity retention over 20 K cycles at 10 A g^(-1).An excellent electrochemical performance is obtained even at a high mass loading of 6 mg cm^(-2).Moreover,a flexible quasi-solid-state Bi I_(3)-Zn battery exhibits satisfactory battery performances.This work provides a new idea for designing high-performance aqueous battery with dual mechanisms.

关键词： Aqueous BiI_(3)-Zn battery Dual mechanisms I^(-)-induced uniform zinc deposition Ultralong cyclic life Flexible quasi-solid-state battery

Highly sensitive fluorescent sensing and photocatalytic degradation performance of two-dimensional Tb-organic network

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Journal of Rare Earths 2024年第2期42卷 303-313,I0003页

作者： Ting Gao Zhihu Ma Yixia Ren Zhixiang Wang Meili Zhang Xiaoli Chen Jijiang Wang Laboratory of New Energy and New function Materials Shaanxi Key Laboratory of Chemical Reaction EngineeringCollege of Chemistry and Chemical EngineeringYan'an UniversityYan'an716000China

A novel tetra-nuclear Tb-organic network,named as [Tb_(4)(2-pyia)_(6)(HAc)_(0.5)(2,2'-bipy)(H_(2)O)_(4.5)]·2,2'-bipy·H_(2)O(1),was synthesized hydrothermally based on 5-(pyridin-2-ylmethoxy) isophthalic acid(H_(2)pyia) and 2,2'-bipyridine(2,2'-bipy) ligands,and characterized by single crystal X-ray diffraction,thermogravimetric(TG) analyses,powder X-ray diffraction(PXRD) and infrared(IR) technology.1 possesses a two-dimensional network based on the tetra-nuclear inorganic building units,and the π-πstacking interactions between the pyia^(2-) ligands and the guest 2,2'-bipy molecules play an important role in the forming of 3D supramolecular structure.1 exhibits excellent fluorescent sensing performance for Fe^(3+)(1.26×10^(-8) mol/L),Cr_(2)O_(7)^(2-)(8.1×10^(-7) mol/L),2,4,6-trinitrophenol(TNP)(2.71×10^(-8) mol/L)and tetracycline(TCT)(2.76×10^(-7) mol/L) in aqueous solution with lower detection concentrations.The sensing mechanisms of 1 were investigated by density functional theory(DFT) calculations,ultraviolet-visible(UV-Vis) diffuse reflectance spectroscopy,PXRD and fluorescent lifetime analyses.The activated product of 1 was prepared by heating at 255℃ under constant pressure and used to photo-catalytically degrade TCT.Both 1 and the activated one have good photocatalytic degradation performance for TCT with degradation rates of 84.29% and 96.07%,respectively.The photocatalytic mechanisms were discovered by UV-Vis diffuse reflectance spectroscopy and radical trap experiments.The Tb-organic framework might be an excellent multifunctional fluorescent sensor and a good photocatalytic agent for TCT degradation in the future.

关键词： Tb-organic network Fluorescent sensing Photocatalytic degradation Rare earths