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Effect of electromagnetic parameters on melt flow and heat transfer of AZ80 Mg alloy during differential phase electromagnetic DC casting based on numerical simulation

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China Foundry 2022年第3期19卷 191-200页

作者： yong-hui jia Cheng-lu Hu Qi-chi Le Wen-yi Hu Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China Longyan University College of Chemistry and Materials ScienceLongyan 364012FujianChina

Based on multi-physical field coupling numerical simulation method,magnetic field distribution,melt flow,and heat transfer behavior of aΦ300 mm AZ80 alloy billet during differential phase electromagnetic DC casting(DP-EMC)with different electromagnetic parameters were *** results demonstrate that the increase in current intensity only changes the magnitude but does not change the Lorentz force's distribution *** maximum value of the Lorentz force increases linearly followed by an increase in current *** the frequency increases,the Lorentz force's r component remains constant,and the z component decreases *** change in current intensity correlates with the melt oscillation and convection intensity positively,as well as the liquid sump temperature *** does not mean that the higher the electric current,the better the metallurgical quality of the billet.A lower frequency is beneficial to generate a more significant melt flow and velocity fluctuation,which is helpful to create a more uniform temperature *** DP-EMC parameters for aΦ300 mm AZ80 Mg alloy are 10-20 Hz frequency and 80-100 A current intensity.

关键词： heat transfer melt flow differential phase electromagnetic field DC casting Mg alloy

Effect of harmonic magnetic field and pulse magnetic field on microstructure of high purity Cu during electromagnetic direct chill casting

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China Foundry 2021年第2期18卷 141-146页

作者： Lei Bao Da-zhi Zhao Yin-ji Zhao yong-hui jia Xuan Wang Qi-chi Le Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

The effects of two types of magnetic fields,namely harmonic magnetic field(HMF)and pulse magnetic field(PMF)on magnetic flux density,Lorentz force,temperature field,and microstructure of high purity Cu were studied by numerical simulation and experiment during electromagnetic direct chill *** magnetic field is induced by a magnetic generation system including an electromagnetic control system and a cylindrical crystallizer of 300 mm in diameter equipped with excitation coils.A comprehensive mathematical model for high purity Cu electromagnetic casting was established in finite element *** distributions of magnetic flux density and Lorentz force generated by the two magnetic fields were acquired by simulation and experimental *** microstructure of billets produced by HMF and PMF casting was *** show that the magnetic flux density and penetrability of PMF are significantly higher than those of HMF,due to its faster variation in transient current and higher peak value of magnetic flux *** addition,PMF drives a stronger Lorentz force and deeper penetration depth than HMF does,because HMF creates higher eddy current and reverse electromagnetic field which weakens the original electromagnetic *** microstructure of a billet by HMF is composed of columnar structure regions and central fine grain *** contrast,the billet by PMF has a uniform microstructure which is characterized by ultra-refined and uniform grains because PMF drives a strong dual convection,which increases the uniformity of the temperature field,enhances the impact of the liquid flow on the edge of the liquid pool and reduces the curvature radius of liquid ***,PMF shows a good prospect for industrialization.

关键词： high purity Cu pulse magnetic field harmonic magnetic field microstructure sputtering target direct chill casting

Ultrasonic flaw detection of discontinuous defects in magnesium alloy materials

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China Foundry 2019年第4期16卷 256-261页

作者： Sheng-nan Xue Qi-chi Le yong-hui jia Li-ping jiang Zhi-qiang Zhang Lei Bao Key Lab of Electromagnetic Processing of Materials Ministry of Education Northeastern University

Phased array ultrasonic testing, an effective ultrasonic testing(UT) technology, has been widely used in steel inspection because of its high accuracy, sensitivity, and efficiency. However, as its application in as-cast magnesium alloys has just begun, more research is needed. Considering the important role of the gain compensation in quantifying defects in magnesium alloys by ultrasonic phased array technology, the effects of microstructure, the position, size, and overlap of defects, and boundary distance(distance from the defect position to the side surface of the test casting) on gain compensation of as-cast AZ80 and AZ31 magnesium alloys were studied. Results show the gain compensation increases with the increase of grain size. There is a strict linear positive correlation between gain compensation and defect depth, but such relationship no longer exists due to the defects overlap, orientation and boundary distance. In addition, there is a strict linear negative correlation between the gain compensation and defect size.

关键词： magnesium alloy ultrasonic phased array defect detection gain compensation

Optimization of the co-closing law of guide vanes and blades for bulb turbines based on CFD

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Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： hui Liu Yun-fa Lin yong-guang Cheng Song Xue Mao-jia Tang jian Zhang jia-yi Fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric Machinery Co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co-closing law of GVs and RBs by using computational fluid dynamics(CFD),combined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by controlling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’second-stage closing speed is conducive to controlling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each control parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization computational fluid dynamics(CFD)

Progress in research on metal-based materials in stabilized Zn anodes

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Rare Metals 2024年第1期43卷 20-40页

作者： Le Li Shao-Feng jia Ming-hui Cao yong-Qiang Ji Heng-Wei Qiu Dan Zhang Shaanxi Key Laboratory of Industrial Automation School of Mechanical EngineeringShaanxi University of TechnologyHanzhong 723001China School of Electronic and Information Engineering Qingdao UniversityQingdao 266071China State Key Laboratory for Artifcial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Department of Chemistry Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyTsinghua UniversityBeijing 100084China Shaanxi Key Laboratory of Catalysis School of Chemistry and Environment ScienceShaanxi University of TechnologyHanzhong 723001China

Aqueous zinc-ion batteries(ZIBs) combine the benefits of metallic Zn anodes with those of aqueous electrolytes and are well suited for large-scale energy storage because of their inherent high safety, cost-effectiveness, and eco-friendliness. Currently, the practical application of such batteries is hindered by the poor cycling performance of Zn anodes due to uncontrolled dendrite formation and severe side reactions, although recent reports suggest that these problems can be mitigated through the modification of Zn anodes with metal-based *** that the mechanisms of improving Zn deposition and the structural evolution of metal-based materials have not been systematically reviewed, we herein systematically overview the metal-based materials used to stabilize Zn anodes, starting with a brief summary of the anode working mechanism and the challenges faced by stabilized Zn anodes. Subsequently, the design principles of Zn anodes stabilized by metal-based materials and the related recent progress are reviewed, and the key challenges and perspectives for the future development of such Zn anodes are proposed.

关键词： Zinc-ion batteries(ZIBs) Zn anode Metalbased materials Alloying metal Stabilized Zn anodes

Extending Structures for Gel'fand-Dorfman Bialgebras

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Acta Mathematica Sinica,English Series 2024年第2期40卷 619-638页

作者： jia jia WEN Yan yong HONG School of Mathematics Hangzhou Normal UniversityHangzhou 311121P.R.China

Gel'fand-Dorfman bialgebra,which is both a Lie algebra and a Novikov algebra with some compatibility condition,appeared in the study of Hamiltonian pairs in completely integrable *** also emerged in the description of a class special Lie conformal algebras called quadratic Lie conformal *** this paper,we investigate the extending structures problem for Gel'fand-Dorfman bialgebras,which is equivalent to some extending structures problem of quadratic Lie conformal ***,given a Gel'fand-Dorfman bialgebra(A,o,[.,.]),this problem is how to describe and classify all Gel'fand-Dorfman bialgebra structures on a vector space E(A⊂E)such that(A,o,[.,.])is a subalgebra of E up to an isomorphism whose restriction on A is the identity *** by the theories of extending structures for Lie algebras and Novikov algebras,we construct an object gH2(V,A)to answer the extending structures problem by introducing the notion of a unified product for Gel'fand-Dorfman bialgebras,where V is a complement of A in *** particular,we investigate the special case when dim(V)=1 in detail.

关键词： Gel'fand-Dorfman bialgebra Lie conformal algebra Extending structures problem Novikovalgebra

Nanoscale Reorganization of Glutamate Receptors Underlies Synaptic Plasticity and Pathology

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Neuroscience Bulletin 2024年第6期40卷 840-844页

作者： jia-hui Chen Ai-hui Tang Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Brain Function and DiseaseNeurodegenerative Disorder Research Center and Biomedical Sciences and Health Laboratory of Anhui ProvinceUniversity of Science and Technology of ChinaHefei230027China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei230088China

Excitatory synapses serve as the primary sites for information transmission between neurons in the *** work over the past decades has identified and revealed multiple compositions and functions of the synaptic proteome in the postsynaptic density(PSD),including receptors,scaffold proteins,and signaling molecules,which work together to ensure stable and effective synaptic transmission.

关键词： Receptor scale Glutamate

Graphitic carbons: preparation, characterization,and application on K-ion batteries

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Rare Metals 2024年第9期43卷 4056-4075页

作者： Kang-Zhe Cao jia-hui Ma Yu-Lian Dong Yu Duan Run-Tian Zheng Dharani Bundhooa hui-Qiao Liu yong Lei College of Chemistry and Chemical Engineering Xinyang Normal University Xinyang Key Laboratory of Low-Carbon Energy Materials Fachgebiet Angewandte Nanophysik Institut für Physik & IMN MacroNano Technische Universit?t Ilmenau Laboratory of Inorganic Materials Chemistry (CMI) University of NamurB-5000 Namur

K-ion batteries(KIBs) have drawn much attention due to the abundant potassium reserves and wide accessibility as well as high energy density, which can be designed for large-scale energy storage systems. As the most promising anode materials for KIBs, graphitic carbons, especially those with an intermediate structure between the crystalline graphite and amorphous carbons become a hot research focus because of the improved rate capability and enhanced diffusion-controlled capacity at low voltage regions. Herein, we first review the structures of graphitic carbons in the view of graphitic domains and the structure changes in their K-ion intercalation compounds. Then, we summarize the preparation mechanisms and characterizations of graphitic carbons and the influence factors in their degree of graphitization. Furtherly, we illustrate the strategies to optimize their K-ion storage properties from four aspects, namely graphitic domain design, microstructure engineering, electrochemical active component regulation, and defect engineering. Finally, we propose the issues that urgently need to be solved in graphitic carbons and the possible solutions. We hope that this view could offer some inspiration for the further designing and optimizing of graphitic carbons for practical KIBs.

关键词： Anodes

Enhanced preparation of dendritic metallic vanadium in recyclable NaCl-KCl-VCl_(2) molten salt by V_(2)CO electrolysis

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Rare Metals 2024年第8期43卷 3961-3973页

作者： jia-Liang An Ming-yong Wang yong-Zheng jia Jin-Tao Zhang Bao-Yan Feng Shu-Qiang jiao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China College of Material Science and Engineering Hebei Province Laboratory of Inorganic Nonmetallic MaterialsNorth China University of Science and TechnologyTangshan 063210China

A promising method for the preparation of pure metallic vanadium via V_(2)CO anode electrolysis was proposed and *** simple and controllable synthesis of a molten chloride salt containing VCl_(2) by an insitu reaction between VCl_(3) and metallic vanadium was verified through thermodynamic analysis and ***-KCl-VCl_(2) molten salt exhibited excellent recycling performance and could be repetitively used to prepare metallic vanadium by V_(2)CO *** V^(2+) ions remained in the molten salt after *** electrolysis conditions,such as the cathode diameter,current density,V^(2+) ion concentration,and temperature,were optimised to maximise the current *** was also simulated to reveal the regulatory *** highest current efficiency was 85%.The purity of metallic vanadium was up to 99.8%.In this study,an easy and efficient preparation of pure metallic vanadium was achieved.

关键词： V_(2)CO Metallic vanadium Current efficiency Molten salt electrolysis