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Strain gradient Finite Element Formulation of Flexoelectricity in Ferroelectric Material Based on Phase-Field Method

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Acta Mechanica Solida Sinica 2024年第4期37卷 570-579页

作者： Shuai Wang Hengchang Su min Yi Li-hua Shao National Key Laboratory of Strength and Structural Integrity Institute of Solid MechanicsSchool of Aeronautic Science and EngineeringBeihang UniversityBeijing100191People’s Republic of China State Key Laboratory of Mechanics and Control for Aerospace Structures and Institute for Frontier Science and Key Laboratory for Intelligent Nano Materials and Devices of ministry of Education and College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China

Flexoelectricity is a two-way coupling effect between the strain gradient and electric field that exists in all dielectrics,regardless of point group ***,the high-order derivatives of displacements involved in the strain gradient pose challenges in solving electromechanical coupling problems incorporating the flexoelectric *** this study,we formulate a phase-field model for ferroelectric materials considering the flexoelectric effect.A four-node quadrilateral element with 20 degrees of freedom is constructed without introducing high-order shape *** microstructure evolution of domains is described by an independent order parameter,namely the spontaneous polarization governed by the time-dependent ginzburg–Landau *** model is developed based on a thermodynamic framework,in which a set of microforces is introduced to construct the constitutive relation and evolution *** the flexoelectric part of electric enthalpy,the strain gradient is determined by interpolating the mechanical strain at the node via the values of gaussian integration points in the isoparametric *** model is shown to be capable of reproducing the classic analytical solution of dielectric materials incorporating the flexoelectric *** model is verified by duplicating some typical phenomena in flexoelectricity in cylindrical tubes and truncated pyramids.A comparison is made between the polarization distribution in dielectrics and *** model can reproduce the solution to the boundary value problem of the cylindrical flexoelectric tube,and demonstrate domain twisting at domain walls in ferroelectrics considering the flexoelectric effect.

关键词： Flexoelectricity Phase-field method Ferroelectrics Domain configuration

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Structure and 2p decay mechanism of^(18)Mg

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Nuclear Science and Techniques 2024年第6期35卷 145-154页

作者： Long Zhou De-Qing Fang Si-min Wang Hui hua Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China

The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,*** study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body gamow coupled-channel *** results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave ***,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C ***,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of *** observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.

关键词： Structure of^(18)Mg Two-proton decay Proton-proton correlation

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One-pot synthesis of a giant twisted double-layer chiral macrocycle via [4+8] imine condensation and its X-ray structure

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Chinese Chemical Letters 2024年第10期35卷 241-243页

作者： Yu Pang min Wang Ning-hua Yang min Xue Yong Yang School of Science Department of PhysicsKey Laboratory of Optical Field Manipulation of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China School of Chemistry and Chemical Engineering Key Laboratory of Surface&Interface Science of Polymer Materials of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou310018China

Trifluoroacetic acid(TFA)catalyzed condensation reaction between tetraaminooxacalix[4]arene and N-alkylcarbazole-3,6-dicarbaldehyde in CH_(2)Cl2afforded a single product in 87%–89%***-defined yet undissolvable1H NMR spectra suggested formation of robust and discrete structures in solution.X-ray single crystal analysis further revealed a giant twisted double-layer chiral macrocycle in the solid state,which was formed from[4+8]condensation of the two reactants via 16 imine *** calculations discovered that only the[4+8]twisted product is thermodynamically favorable,which accounts for its highly selective and efficient formation out of a library of many other combinations.

关键词： One-pot synthesis Oxacalixarene Dynamic covalent chemistry Chiral macrocycle X-ray single crystal

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Treatment of multisystem inflammatory syndrome in children

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World Journal of Pediatrics 2024年第4期20卷 325-339页

作者： Tong Tong Yi-hua Jin min Wang Fang-Qi gong Department of Cardiology Children's HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthNo.3333 Binsheng RoadHangzhou 310052China

Background Multisystem inflammatory syndrome in children(MIS-C),a relatively uncommon but severe pediatric complication,is associated with coronavirus disease 2019(COVID-19).A variety of treatment approaches,including intravenous immunoglobulins(IVIgs),glucocorticoids(gCs)and biologic agents,such as anakinra and infliximab,have been described for the management of COVID-19-related *** therapy is also ***,a well-developed treatment system has not been established,and many issues remain *** recently published articles related to the treatment of MIS-C have been ***,in this review,we identified relevant articles published recently and summarized the treatment of MIS-C more comprehensively and *** sources We reviewed the literature on the treatment of MIS-C through 20 September *** PubMed/Medline,Web of Science,EMBASE,and Cochrane Library databases were searched with the combination of the terms"multisystem inflammatory syndrome","MIS-C","PIMS-TS","therapy","treatment","drug","IVIg","gCs","intravenous immunoglobulin","corticosteroids","biological agent",and"aspirin".Results The severity of MIS-C varies,and different treatment schemes should be used according to the specific *** research and data collection are vital to better understand the pathophysiology and optimal management of *** MIS-Cis a disease involving multiple systems and has great *** the accumulation of additional experience,we have garnered fresh insights into its treatment ***,there remains a critical need for greater standardization in treatment protocols,alongside the pressing necessity for more robust and meticulously conducted studies to deepen our understanding of these protocols.

关键词： Coronavirus disease 2019-Corticosteroids Intravenous immunoglobulin Multisystem inflammatory syndrome in children-Treatment

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Efficient optimization of electron transfer pathway by constructing phosphide/ceria interface boosts seawater hydrogen production

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Journal of Energy Chemistry 2024年第8期95卷 490-498,I0011页

作者： Yifan Zhao Lingfeng Yang Youyu Long min Xi Anran Chen hua Zhang School of Materials and Energy Yunnan UniversityKunming 650091YunnanChina Electron Microscopy Centre of Yunnan University Yunnan UniversityKunming 650091YunnanChina

Developing efficient and durable hydrogen evolution reaction(HER)electrocatalysts is one of the most important issues for the commercialization of seawater electrolysis,but it remains ***,we report a CeO_(2)-CoP nanoneedle array catalyst loaded on Ti mesh(CeO_(2)-CoP/TM)with workfunction-induced directional charge transport *** CeO_(2)-CoP/TM catalyst showed superior HER catalytic activity and stability,with over potentials of 41 and 60 mV to attain 10 mA cm^(-2),in 1 M KOH and 1 M KOH+seawater electrolyte,*** results and theoretical calculations reveal that the work function drives the charge transfer from CeO_(2)to CoP,which effectively balances the electronic density of CoP and CeO_(2),optimizes the d-band center,and accelerates the water activation kinetics,thus enhancing the HER *** solar-driven water electrolysis device displays a high and stable solar-to-hydrogen conversion efficiency of 19.6%.This study offers a work function-induced directional charge transport strategy to design efficient and durable catalysts for hydrogen production.

关键词： Work function Heterostructure Charge transport Seawater splitting Solar-to-hydrogen

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Lewis Base Catalyzed Selenofunctionalization of Alkynes with Acid-Controlled Divergent Chemoselectivity

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Chinese Journal of Chemistry 2024年第14期42卷 1623-1629页

作者： Ling-Ling Chen Ren-Fei Cao hua Ke Zhi-min Chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai200240 China Engineering Technology Research Center for Environmental Protection Materials Pingxiang UniversityPingxiangJiangxi337055 China

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first *** selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z *** the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.

关键词： Alkynes Electrophilic addition Chemoselectivity Lewis base catalysis Selenofunctionalization

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Revisiting the island of hexadecapoledeformation nuclei in the A≈150 mass region:focusing on the model application to nuclear shapes and masses

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Communications in Theoretical Physics 2024年第2期76卷 74-88页

作者： Xiao-Yang Wei hua-Lei Wang Zhen-Zhen Zhang min-Liang Liu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Based on the potential-energy-surface calculation,the impact of different deformation degrees of freedom on a single-particle structure and binding energies in nuclei around^(152)Nd,located on one of the hexadecapole-deformation islands,is analyzed in a multi-dimensional deformation *** energy maps,curves and tables are presented to indicate nuclear *** calculated equilibrium deformations and binding energies with different potential parameters are compared with experimental data and other *** is found that the inclusion of the hexadecapole deformations,especially the axial one,can improve the theoretical description of both nuclear shapes and *** addition,our calculated potential-energy curve shows that a critical deformation-point,β_(2)≈0.4,exists—the triaxial(hexadecapole)deformation effect can be neglectable but the hexadecapole(triaxial)one plays an important role before(after)such a critical point.

关键词： hexadecapole deformation binding energy potential-energy-surface calculation nuclear property

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Trends and hotspots in gastrointestinal neoplasms risk assessment: A bibliometric analysis from 1984 to 2022

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World Journal of gastrointestinal Oncology 2024年第6期16卷 2842-2861页

作者： Qiang-Qiang Fu Le Ma Xiao-min Niu hua-Xin Zhao Xu-hua ge hua Jin De-hua Yu Sen Yang Department of general Practice Yangpu HospitalSchool of MedicineTongji UniversityShanghai 200090China Shanghai general Practice and Community Health Development Research Center Shanghai 200090China Department of Shanghai Lung Cancer Center Shanghai Chest HospitalShanghai Jiao Tong University School of MedicineShanghai 200030China Department of Oncology Shanghai Tenth People’s HospitalTongji University School of MedicineShanghai 200090China

BACKgROUND gastrointestinal neoplasm(gN)significantly impact the global cancer burden and mortality,necessitating early detection and *** the evolution and current state of research in this field is *** To conducts a comprehensive bibliometric analysis of publications from 1984 to 2022 to elucidate the trends and hotspots in the gN risk assessment research,focusing on key contributors,institutions,and thematic *** This study conducted a bibliometric analysis of data from the Web of Science Core Collection database using the"bibliometrix"R package,VOSviewer,and *** analysis focused on the distribution of publications,contributions by institutions and countries,and trends in *** methods included data synthesis,network analysis,and visualization of international collaboration *** This analysis of 1371 articles on gN risk assessment revealed a notable evolution in terms of research focus and *** highlights the United States'critical role in advancing this field,with significant contributions from institutions such as Brigham and Women's Hospital and the National Cancer *** last five years,substantial advancements have been made,representing nearly 45%of the examined *** rates have dramatically increased,from 20 articles in 2002 to 112 in 2022,reflecting intensified research *** study underscores a growing trend toward interdisciplinary and international collaboration,with the Journal of Clinical Oncology standing out as a key publication *** shift toward more comprehensive and collaborative research methods marks a significant step in addressing gN *** This study underscores advancements in gN risk assessment through genetic analyses and machine learning and reveals significant geographical disparities in research *** calls for enhanced global collaboration and integration of artificial intelligence to improve cancer p

关键词： gastrointestinal neoplasms Bibliometric analysis Risk assessment Network analysis Research trends

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The dynamics beamline at SSRF

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Nuclear Science and Techniques 2024年第9期35卷 56-67页

作者： Zhen Liu Li-hua Wang Yong Jiang Ya-Jun Tong hua-Chun Zhu Te Ji min Chen Zheng Jiang Xiang-Jun Wei Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China ShanghaiTech University Shanghai 201210China

The dynamics beamline(D-Line),which combines synchrotron radiation infrared spectroscopy(SR-IR)and energy-disper-sive X-ray absorption spectroscopy(ED-XAS),is the first beamline in the world to realize concurrent ED-XAS and SR-IR measurements at the same sample position on a millisecond time-resolved *** combined technique is effective for investigating rapid structural changes in atoms,electrons,and molecules in complicated disorder systems,such as those used in physics,chemistry,materials science,and extreme ***,ED-XAS and SR-IR can be used independently in the two branches of the *** ED-XAS branch is the first ED-XAS beamline in China,which uses a tapered undulator light source and can achieve approximately 2.5×10^(12)photons/s·300 eV BW@7.2 keV at the sample *** exchange-able polychromator operating in the Bragg-reflection or Laue-transmission configuration is used in different energy ranges to satisfy the requirements for beam size and energy *** focused beam size is approximately 3.5μm(H)×21.5μm(V),and the X-ray energy range is 5–25 *** one-and two-dimensional position-sensitive detectors with frame rates of up to 400 kHz enables time resolutions of tens of microseconds to be *** distinctive techniques,such as the concurrent measurement of in situ ED-XAS and infrared spectroscopy,time-resolved ED-XAS,high-pressure ED-XAS,XMCD,and pump-probe ED-XAS,can be applied to achieve different scientific goals.

关键词： ED-XAS SR-IR Time-resolved D-line SSRF

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K doping stabilizes three-dimensional K0.2Na1.3Mn0.5O2-δ as high-performance cathode for sodium-ion batteries

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Rare Metals 2024年第10期43卷 5030-5038页

作者： Jia-Hao Xu You-huan Zhu Wei-min Yang hua Cheng Zhou-guang Lu Industrial Training Center Shenzhen Polytechnic University Department of Materials Science and Engineering Southern University of Science and Technology School of Materials Science and Environmental Engineering Shenzhen Polytechnic University

It is a difficult challenge to simultaneously employ the cationic and anionic redox chemistry in cathode materials for sodium-ion batteries with high *** though layered oxides （classified as two-dimensional oxides） demonstrate excellent promise in the high discharge capacity,their poor oxygen transformation via redox reactions is limited by crystal ***,a doping strategy was conceived to tackle this issue and increase redox efficiency.K doping was applied to transform the two-dimensional Na1.3Mn0.7O2（NMO） to threedimensional K0.2Na1.3Mn0.5O2（KNMO）,preventing the irreversible phase shift and preserving the crystal structure’s stability while *** this modification treatment,KNMO features manganese and oxygen reactive sites,delivering a promising energy density of 190mAh·g-1at 5 mA·g-1in the 2.0–4.5 V voltage range (vs71.4 mAh·g-1for the pristine NMO).Moreover,it displays improved capacity retention of more than 83.5% after 50cycles at 50 mA·*** results demonstrated that doped intercalation oxides were promising for redox oxygen transformation in sodium-ion batteries.

关键词： High-performance cathode Metal ion dopings Sodium-ion batteries Three-dimensional structure

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