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Three‑Dimensional Numerical Study on the Metal Rotating Spray Transfer Process of High‑Current GMAW

Chinese Journal of Mechanical Engineering 2022年第6期35卷 234-246页

作者： Lei xiao Ding fan Jiankang Huang School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China State Key Laboratory of Advanced Processing and Recycling of Non‑ferrous Metals Lanzhou University of TechnologyLanzhou 730050China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China

A three-dimensional numerical model based on the volume-of-fluid(VOF)method is typically preferred for studying high-current gas metal arc welding(GMAW)metal transfer mechanism and then controlling it.It is informed that the rotating spray transfer is extremely complicated,and some researchers have focused on simplified models without considering the energy conservation to make analysis manageable for the unstable metal transfer process.Using our created numerical model,the metal transfer of high-current GMAW with shielding gas of different conductivities has been studied by analyzing acting forces and fluid flows in the metal liquid column,especially for the contributions of the self-induced electromagnetic force,equivalent volume force of the capillary pressure of the surface tension(Named surface tension force in this work),static arc pressure.It is found that the unbalanced electromagnetic force greatly promotes the metal rotating motion in 500 A metal inert gas(MIG)welding with pure argon shielding gas and it pushes the metal liquid column to rotate.Considering the arc constricting effect in active shielding gas by simply changing the arc conductivity,it is found that the metal liquid column no longer rotates,it turns to swing since the unbalanced electromagnetic force is large enough to break the rotating motion.The calculated results of the metal liquid column deflected angle and rotating/swing frequency agree well with the experiment of high-speed camera observations.

关键词： Gas metal arc welding Rotating spray transfer Three-dimensional model Electromagnetic force Surface tension

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Comparison Properties for Asymptotically Tracially Approximation C^(*)-algebras

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Acta Mathematica Sinica,English Series 2023年第5期39卷 863-884页

作者： Qing Zhai fan xiao Chun fanG College of Education Shanghai Jian Qiao UniversityShanghai 201306P.R.China Department of Mathematics Shanghai Maritime UniversityShanghai 201306P.R.China Department of Mathematics Tongji UniversityShanghai 200092P.R.China

We show that the following properties of the C*-algebras in a class P are inherited by simple unital C*-algebras in the class of asymptotically tracially in P :(1) n-comparison,(2) α-comparison(1 ≤ α < ∞).

关键词： C*-algebras asymptotically tracially approximation Cuntz semigroup

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Typology and working mechanism of a hybrid power router based on power-frequency transformer electromagnetic coupling with converters

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Protection and Control of Modern Power Systems 2023年第3期8卷 80-96页

作者： Jinmu Lai Xin Yin Xianggen Yin Jiaxuan Hu Fan Xiao School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001Henan ProvincePeople’s Republic of China School of Automation Wuhan University of TechnologyWuhan 430070Hubei ProvincePeople’s Republic of China School of Electrical and Electronic Engineering Huazhong University of Science and Technology(HUST)Wuhan 430074Hubei ProvincePeople’s Republic of China State Grid Hubei Electric Power Research Institute Wuhan 430077Hubei ProvincePeople’s Republic of China

The power router(PR)is a promising piece of equipment for realizing multi-voltage level interconnection and flex-ible power control in the future distribution power grid.In this paper,a hybrid PR(HPR)topology based on power-frequency transformer electromagnetic coupling with converters is proposed for the medium distribution power grid.The power-frequency transformer is used to undertake power transmission,voltage conversion,and other main tasks,while the power electronic converters are combined to achieve active control.Equivalent magnetic and electrical circuit models are established to help discuss the operating principle of the proposed HPR.Additionally,the power flow and control principle of the HPR in different operating conditions are analyzed,with the control system design scheme presented.The theoretical analysis results are verified by MATLAB/Simulink+Plecs simulation and a controller hardware-in-the-loop study,as well as a down-scale experimental test,indicating that the proposed HPR is flexible in active voltage support and current control.

关键词： Power router Power-frequency transformer Power electronic converter Hybrid Working mechanism

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Progress in understanding hormonal regulation during the postembryonic development of Helicoverpa armigera

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Journal of Integrative Agriculture 2020年第6期19卷 1417-1428页

作者： ZHAO xiao-fan Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology School of Life SciencesShandong UniversityQingdao 266237P.R.China

Lepidoptera,with 0.16 million species,is the second largest order of insecta.This order includes silk worms,butterflies,and many agricultural pests.The cotton bollworm,Helicoverpa armigera(Hubner)is one of the pests in Lepidoptera that seriously harms cotton plant and other crops in China and other countries.This pest develops resistance to chemical insecticides rapidly.Bacillus thuringiensis(Bt)transgenic cotton plants are developed to control H.armigera population in the field.However,duri ng the past years,the rapid evoluti on of Bt toxi n resista nee is observed in H.armigera in tran sge nic cott on fields.New approaches for the development of new envir on mentally friendly insecticides to control H.armigera have become necessary,and the molecular mechanisms underlying the development and physiological processes of this species need to be further understood.Considerable progress in the study of H.armigera development and physiology has been achieved in the last decade.This mini-review summarizes the main fin dings on the molecular mechanisms of horm onal regulation of the development of H.armigera to present new target genes for developing new approaches to control the pest.

关键词： Helicoverpa armigera Lepidoptera hormonal regulation development pest control

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Structural and Operational Optimization of A Flapping Fin Used as A Self-Propulsor for AUV Propulsion

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China Ocean Engineering 2022年第1期36卷 86-99页

作者： fan Shuang-shuang CI xiao-han Neil BOSE CHENG xiao School of Marine Sciences Sun Yat-sen UniversityZhuhai 519082China Southern Laboratory of Ocean Science and Engineering Zhuhai 519000China Department of Ocean and Naval Architectural Engineering Memorial University of NewfoundlandSt.John’sNL A1C 5S7Canada School of Geospatial Engineering and Science Sun Yat-sen UniversityZhuhai 519082China

Marine mammals could directly harvest energy from waves and obtain propulsive force through oscillating flapping fins or horizontal tail flukes,which in many cases have been observed and proved to be substantial.The propulsion generated by the flapping fin has been analyzed by many researchers from both the theoretical and experimental prospects;however,the structural and operational optimization of a flapping fin for the optimal propulsion performance has been less studied,such as the investigation of the effects of the phase difference between heave and pitch motion,maximum oscillation angle,fin shape,oscillation centre of the fin and the operating sea state on the generated propulsion.In this paper,the flapping fin is used as a self-propulsor to propel an autonomous underwater vehicle(AUV)for propulsion assistance.For the optimization design of the flapping fin,its propulsion effect is numerically investigated with different structural parameters and under various operation conditions using computational fluid dynamics(CFD)approaches.Verification and validation study have been implemented to quantify the numerical uncertainties and evaluate the accuracy of the proposed CFD method.Then,a series of case studies are thoroughly conducted to investigate the effects of different structural parameters and operational conditions on the generated propulsion of a flapping fin by CFD simulations.The simulation results demonstrate that different structural parameters and operation conditions would significantly impact the magnitude and distribution state of the fluid pressure around the flapping fin surface,thus,affect the propulsion performance of the fin.The findings in this study will provide guidelines for the structural and operational optimization design of a flapping fin for self-propulsion of mobile platforms.

关键词： autonomous underwater vehicle(AUV) flapping fin self-propulsion computational fluid dynamics(CFD) optimization design

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Advances in magnetic nanoparticle-based magnetic resonance imaging contrast agents

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Nano Research 2023年第11期16卷 12531-12542页

作者： Huan Zhang xiao Li Liu Hai Ming fan Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China Department of Radiology Zhuhai People’s Hospital(Zhuhai Hospital Affiliated with Jinan University)Zhuhai 519000China Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationProvincial Key Laboratory of Biotechnology of Shaanxi ProvinceNorthwest UniversityXi’an 710069China Institute of Regenerative and Reconstructive Medicine Med-X InstituteFirst Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710049China National Local Joint Engineering Research Center for Precision Surgery&Regenerative Medicine Shaanxi Provincial Center for Regenerative Medicine and Surgical EngineeringFirst Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061China

Magnetic resonance imaging(MRI)has revolutionized medical imaging diagnostics with the advantages of non-invasive nature,absence of ionizing radiation,unrestricted penetration depth,high-resolution imaging of soft tissues,organs and blood vessels,and multi-parameter and multi-sequence imaging.Contrast agents(CAs)are crucial for enhancing image quality,detecting molecular-level changes,and providing comprehensive diagnostic information in contrast enhanced MRI.However,the performance of clinical Gd-based CAs represents a limitation to the improvement of MRI sensitivity,specificity,and versatility,thereby impeding the achievement of satisfactory imaging outcomes.In recent years,the development of magnetic nanoparticle-based CAs has emerged as a promising avenue to enhance the capabilities of MRI.Here,we review the advances in magnetic nanoparticle-based MRI CAs,including blood pool CAs,biochemically-targeted CAs,stimulus-responsive CAs,and ultra-high field MRI CAs,as well as the use of CAs for cell labeling and tracking.Additionally,we offer insights into the future prospects and challenges associated with the integration of these nanoparticles into clinical practice.

关键词： magnetic resonance imaging magnetic nanoparticle blood pool contrast agents biochemically-targeted contrast agents stimulus-responsive contrast agents

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An artificial neural network model for multi-flexoelectric actuation of Plates

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International Journal of Smart and Nano Materials 2022年第4期13卷 713-734页

作者： Mu fan Pengcheng Yu Zhongmin xiao State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjingChina Interdisciplinary Research Institute of Aeronautics and Astronautics College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore

Flexoelectric effect can be used to design actuators to control engi-neering structures including beams,plates,and shells.Multiple flexo-electric actuators method has the advantage of less stress concentration and better control effect,but the mode-dependent optimal actuator locations could influence the flexoelectric actuation effect significantly.In this work,a neural network model is established to study the optimal combinations of multiple flexoelectric actuators on a rectangular plate.In the physical model,an atomic force micro-scope(AFM)probe was employed to generate an electric field gradient in the flexoelectric patch,so that flexoelectric control force and moment can be obtained.Multiple flexoelectric actuators on the plate was considered.Case studies showed that the flexoelectricity induced stress mainly concentrate near the probe,the size and shape of the flexoelectric patch have limited effect on the actuation,hence,only the actuator positions were choosing as the input of the ANN model.Using the prediction of the neural network model,the driving effect of a large number of actuators at different positions can be quickly obtained,and the optimal position of the actuator can be analyzed more accurately.

关键词： smart structure flexoelectric effect vibration of thin plate Artificial neural network

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Challenges and Perspectives in Target Identification and Mechanism Illustration for Chinese Medicine

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Chinese Journal of Integrative Medicine 2023年第7期29卷 644-654页

作者： GUO xiao-xi AN Su BAO fan XU Tian-rui Faculty of Life Science and Technology Kunming University of Science and TechnologyKunming650500China The First People’s Hospital of Yunnan Province Kunming650032China

Chinese medicine(CM)is an important resource for human life understanding and discovery of drugs.However,due to the unclear pharmacological mechanism caused by unclear target,research and international promotion of many active components have made little progress in the past decades of years.CM is mainly composed of multi-ingredients with multi-targets.The identification of targets of multiple active components and the weight analysis of multiple targets in a specific pathological environment,that is,the determination of the most important target is the main obstacle to the mechanism clarification and thus hinders its internationalization.In this review,the main approach to target identification and network pharmacology were summarized.And BIBm(Bayesian inference modeling),a powerful method for drug target identification and key pathway determination was introduced.We aim to provide a new scientific basis and ideas for the development and international promotion of new drugs based on CM.

关键词： Chinese medicine target identification network pharmacology Bayesian inference modeling

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Characterization and Trading of Energy Level and Energy Shift Considering Virtual Power Plant

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1784-1789页

作者： Shuai fan Jucheng xiao Zuyi Li Guangyu He Key Laboratory of Control of Power Transmission and Conversion Ministry of EducationShanghai Jiao Tong UniversityShanghai200240China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616USA

The capability of shifting the electricity generation or consumption to proper time of the day,also defined as energy shift(ES),is the key factor to ensure the power balance,especially under high penetration of variable renewable energy(VRE).However,the ES is not characterized and traded as an independent product in current market mechanisms.In this letter,the marginal utility of an ES is assessed and leveraged to characterize the effective ES,while a novel market scheme is proposed considering the trading of both ES and energy level(EL).The proposed scheme can well integrate ES producers such as virtual power plants that cannot be rewarded sufficiently to actively participate in the current market because they are principally labeled as EL consumers.Finally,the novel concept and mechanism are illustrated by a numerical study and verified to outperform the existing price schemes on integrating the ES resources and VRE.

关键词： Energy level energy shift variable renewable energy virtual power plant marginal utility

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Recent advances and trends of heterogeneous electro-Fenton process for wastewater treatment-review

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Chinese Chemical Letters 2022年第2期33卷 653-662页

作者： Zining Wang Mingyue Liu Fan Xiao Georgeta Postole Hongying Zhao Guohua Zhao School of Chemical Science and Engineering and Shanghai Key lab of Chemical Assessment and SustainabilityTongji UniversityShanghai 200092China Univ Lyon UniversitéClaude Bernard Lyon 1CNRSIRCELYONF-69626 VilleurbanneFrance

Electrochemical advanced oxidation processes (EAOPs) are effective and environmentally friendly for the treatment of refractory organic pollutants.Among EAOPs,heterogeneous electro-Fenton (EF) process with in-situ formation of hydrogen peroxide (H_(2)O_(2)) is an eco-friendly,cost-effective and easy-operable technology to generate hydroxyl radicals (;OH) with high redox potential.The generation of;OH is determined by the synergistic H_(2)O_(2)formation and activation.The surface catalytic mechanisms for H_(2)O_(2)activation in the heterogeneous EF process were discussed.Some required features such as heteroatom doping and oxygen groups for H_(2)O_(2)formation via selective two-electron oxygen reduction reaction (ORR) with carbonaceous electrode are summarized.The solid Fenton catalysts and integrated functional cathodes that widely used in heterogeneous EF for wastewater treatment are grouped into few classes.And the brief discussion on catalytic activity and stability of materials over different experimental conditions are given.In addition,the application of heterogeneous EF process on the remediation of emerging contaminants is provided.The challenges and future prospects of the heterogeneous EF processes about catalytic fall-off and multi-step/complex techniques for water purification are emphasized.

关键词： Heterogeneous electro-Fenton Oxygen reduction reaction Hydrogen peroxide Cathodic materials Refractory organic pollutants

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