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Quantifying the strength of magnetic fields using baryon electric charge correlation

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Nuclear Science and Techniques 2024年第8期35卷 5-8页

作者： Xu‑guang huang Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200433China Key Laboratory of Nuclear Physics and Ion‑beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics National Natural Science Foundation of China and Fudan UniversityShanghai 200438China

Although heavy-ion collisions generate strong magnetic fields,their direct measurement is a challenging task.A new observable,the baryon electric charge correlation,was recently found to be sensitive to the magnetic field strength and thus could be used as a magnetometer for heavy-ion ***,this observable may shed light on the equation of state and phase structure of quantum chromodynamics(QCD)under magnetic *** and understanding the phase structure of quantum chromodynamics(QCD)is important in contemporary physics[1].

关键词： charge observable magnetic

Counterion-Mediated Hydrogen Bonding Making Strong Polyelectrolytes pH-Responsive:Current Understanding and Perspectives

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Chinese Journal of Polymer Science 2024年第9期42卷 1270-1277,I0005页

作者： Yue huang guang-Tao Mei Zan Hua guang-Ming Liu Hefei National Research Center for Physical Sciences at the Microscale Department of Chemical PhysicsKey Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of ChinaHefei230026China The Key Laboratory of Functional Molecular Solids Ministry of Educationand Department of Materials ChemistrySchool of Chemistry and Materials ScienceAnhui Normal UniversityWuhu214002China

The counterion-mediated hydrogen bonding(CMHB)is related to the hydrogen bonding between bound counterions and polyelectrolyte chains in polyelectrolyte systems,where the counterions can both electrostatically bind to the charged groups of polyelectrolyte chains and act as hydrogen bond donors or acceptors to form hydrogen bonds with the hydrogen bond sites associated with polyelectrolyte chains simultaneously.A large number of literatures illustrate that strong polyelectrolytes(SPs)are insensitive to pH,which severely limmits the applications of SPs as smart ***,our studies have demonstrated that the CMHB makes SPs *** perspective discusses the mechanism of pH responsiveness of SPs and the pH-tunable properties of SPs,based on the pH-controlled CMHB *** future research directions on the pH responsiveness of SPs are also discussed *** is anticipated that the study of the pH responsiveness of SPs not only will provide a new understanding of the fundamental properties of SPs,but also will greatly expand the applications of SPs in the field of smart materials.

关键词： Counterion binding Hydrogen bond Polyelectrolyte brush Polyelectrolyte complexation

Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine

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China Ocean Engineering 2024年第3期38卷 363-378页

作者： ZHAO Mi YU Wan-li WANG Pi-guang QU Yang DU xiu-li Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China

A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic *** this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.

关键词： computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field

Analytical Solution and Simplified Formula for Added Mass of Horizontal and Vertical Motions of Truncated Cylinders Under Earthquake Action

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China Ocean Engineering 2024年第1期38卷 54-67页

作者： WANG Pi-guang LYU Si-yu QU Yang ZHAO Mi DU xiu-li State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Tech-nologyBeijing 100124China

This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water *** governing equation of the hydrodynamic pressure acting on the cylinder is derived based on the radiation theory with the inviscid and incompressible *** governing equation is solved by using the method of separating variables and analytical solutions are obtained by assigning reasonable boundary *** analytical result is validated by a numerical model using the exact artificial boundary simulation of the infinite *** main variation and distribution characteristics of the hydrodynamic pressure acting on the side and bottom of the cylinder are analyzed for different combinations of wide-height and immersion *** added mass coefficient of the cylinder is calculated by integrating the hydrodynamic pressure and simplified formulas are proposed for engineering *** calculation results show that the simplified formulas are in good agreement with the analytical solutions.

关键词： earthquake hydrodynamic pressure truncated cylinder added mass simplified formula

Highly Hydrolysis-Resistant Polyimide Fibers Prepared by Thermal Crosslinking with Inherent Carboxyl Groups

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Chinese Journal of Polymer Science 2024年第2期42卷 247-255,I0010页

作者： Can-Can Zhang Jun-Long Yang Ya-Jiang huang guang-Xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Easy hydrolysis in alkaline environments limits the use of polyimide fibers in environmental protection. The hydrolysis resistance levels of polyimide fibers can be improved by crosslinking of the macromolecular chains. In this work, crosslinked polyimide fibers(CPI fibers) were produced by intrinsic carboxyl decarboxylation for the first time. The thermal stability of the polyimide fibers containing the intrinsic carboxyl groups(PIC fibers) was studied, and the temperature of the decarboxylation-crosslinking reaction was determined to be 450 ℃. The PIC fibers were hotdrawn to initiate thermal crosslinking of the carboxyl groups and molecular chain orientation at high temperature. The CPI fibers had high tensile strengths(0.72-1.46 GPa) and compressive strengths(401-604 MPa). The oriented macromolecules and chemically crosslinked structure improved the tightness of the molecular chains and endowed the CPI fibers with excellent hydrolytic resistance. The CPI-50 fiber did not dissolve in a 0.5 wt% NaOH solution during heating at 90 ℃ for 10 h, and the tensile strength retention reached 87% when treated in 0.5 wt% NaOH solutions at 90 ℃ for 1 h, providing a guarantee for its application in alkaline corrosive environments.

关键词： Polyimide Carboxyl group Crosslinking Hydrolysis-resistance

Friction moment calculation method for tapered roller bearings under combined loads

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Science China(Technological Sciences) 2024年第8期67卷 2565-2578页

作者： LI XinBin LIU Jing huang SuHe PAN guang School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory for Unmanned Underwater Vehicle Northwestern Polytechnical UniversityXi’an 710072China System Engineering Research Institute Beijing 100094China

Tapered roller bearings(TRBs) can withstand axial loads, radial loads, and overturning moments. The performance, safety, and efficiency of rotating machinery are directly influenced by the friction moments within the TRBs. However, most current research has relied on empirical formulas that focus on axial loads. Additionally, the friction coefficient between the rollers and the inner ring rib has been defined using simple empirical methods. In actual applications, the loads on TRBs are not purely axial or radial, and simple empirical friction coefficients do not adequately account for the varying lubrication conditions. To address this challenge, this study proposes an improved method for calculating the friction moments of TRB under combined axial and radial loads. This study employs a calculation method for sliding friction coefficients that can model dry, boundary, elastohydrodynamic, and mixed lubrication conditions. To demonstrate the advantages of the proposed method, the friction moments obtained using the existing and proposed methods are compared. Additionally, the influence of TRB structural parameters on the friction moment is discussed. An experimental study is conducted to validate the effectiveness of the proposed method. The findings provide valuable insights for designing TRB structural parameters to minimize friction moments.

关键词： tapered roller bearing friction moment structural parameters combined loads

Effect of MgO-Cr_(2)O_(3) and Mg0-MgAl_(2)0_(4)-based refractories on refractory-steel interface reaction and cleanliness of pipeline steel

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Journal of Iron and Steel Research International 2024年第4期31卷 849-860页

作者： guang-mei Yang Cheng Yuan Chang Liu Qiang Wang guang-qiang Li Yong-shun Zou Ao huang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of total oxygen(TO),Al,Nb,Si,Mn,and Cr as well as the composition,number density,and size distribution of inclusions in the molten steel were *** influence of the penetration and erosion degree of the molten steel to the refractory on the steel-refractory interface layer was *** results show that,at 1560℃,the MgO-MgAl_(2)O_(4)-based refractory can better control the contents of TO and the composition of molten steel compared with the MgO-Cr_(2)O_(3)-based *** TO content is only 16×10^(-4) wt.%in the molten steel after reacted with the Mg0-MgAl_(2)O_(4)-based refractory at the end point of refining,4 accounting for 11.5%of that reacted with the MgO-Cr_(2)O_(3)-based refractory(139×10^(-4) wt.%).The number density of inclusions is only 14 mm^(-2),and the average size ofinclusions is only 1.31μm,with thelargest proportion of inclusions in 1-2μm(70%).The Al_(2)O_(3)-MnS-CaO complex inclusions in the original steel changed to complex inclusions dominated by Cr-Nb-Mn-S-O and ***_(2)O_(3),corresponding to the MgO-Cr_(2)O_(3)-based and MgO-MgAl_(2)O_(4)-based refractories,*** ***_(2)O_(3) layer was formed at the reaction interface between MgO-MgAl_(2)O_(4)-based refractory and molten steel,which is helpful to restrict the erosion of refractories and the pollution of molten *** damage mechanism of the MgO-Cr_(2)O_(3)-based refractory is mainly permeation and chemical reaction,while the damage of the MgO-MgAl_(2)O_(4)-based refractory is mainlyscouring erosion.

关键词： MgO-Cr_(2)O_(3)-based refractory MgO-MgAl O_(4)-based refractory Nonmetallic inclusion Erosion interface layer Steel penetration

Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

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Nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie Zhao Jin-Hui Chen Xu-guang huang Yu-Gang Ma 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 Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

Applying deep learning technique to chiral magnetic wave search

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Chinese Physics C 2024年第8期48卷 170-176页

作者： Yuan-Sheng Zhao Xu-guang huang Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200433China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics National Natural Science Foundation of China and Fudan UniversityShanghai 200438China

The chiral magnetic wave(CMW)is a collective mode in quark-gluon plasma originated from the chiral magnetic effect(CME)and chiral separation *** detection in heavy-ion collisions is challenging owing to significant background ***[*** et al.,***.C 106,L051901(2022)],we constructed a neural network that accurately identifies the CME-related signal from the final-state pion *** this study,we have generalized this neural network to the case of CMW *** show that,after an updated training,the neural network effectively recognizes the CMW-related ***,we have assessed the performance of the neural network in comparison with other known methods for CMW search.

关键词： deep learning chiral magnetic wave relativistic heavy-ion collisions