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A Controversial Political View: Rorty's Moral Finitism and Religion in the Public Square
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作者 Joaquin Jareno 《Journal of Philosophy Study》 2015年第3期136-145,共10页
Richard Rorty's moral finitism is based on some ideas from John Stuart Mill's work On Liberty. For Rorty, religious truths would be the main obstacles for the development of freedom and, at the same time, for human ... Richard Rorty's moral finitism is based on some ideas from John Stuart Mill's work On Liberty. For Rorty, religious truths would be the main obstacles for the development of freedom and, at the same time, for human happiness. Rorty introduces the concepts of contingency and literary culture to express the situation of personal moral development, stressing that our life must be seen as an endless narration. So, there is no fixed development given once and for all. Rorty's anticlericalism is also based on the idea that the creation of clerical institutions and hierarchies is dangerous in the sense that they pose demands which go beyond individual perspectives and make religious obligations be prior to moral ones. Nevertheless, there are some misconceptions in Rorty's position when he discusses the idea of moral obligation and the relationship between religion and religious institutions. 展开更多
关键词 RELIGION public square moral finitism CONTINGENCY NARRATIVE anticlericalism religious institutions
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Rapid rupture characterization for the 2023 M_(S)6.2 Jishishan earthquake 被引量:2
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作者 Xiongwei Tang Rumeng Guo +5 位作者 Yijun Zhang Kun Dai Jianqiao Xu Jiangcun Zhou Mingqiang Hou Heping Sun 《Earthquake Research Advances》 CSCD 2024年第2期22-26,共5页
On December 18, 2023, the M_(S)6.2 Jishishan earthquake occurred in the northeastern region of the QinghaiXizang Plateau, causing heavy casualties and property damage in Gansu and Qinghai Provinces. In this study,we i... On December 18, 2023, the M_(S)6.2 Jishishan earthquake occurred in the northeastern region of the QinghaiXizang Plateau, causing heavy casualties and property damage in Gansu and Qinghai Provinces. In this study,we integrate space imaging geodesy, finite fault inversion, and back-projection methods to decipher its rupture property, including fault geometry, coseismic slip distribution, rupture direction, and propagation speed. The results reveal that the seismogenic fault dips to the southwest at an angle of 29°. The major slip asperity is dominated by reverse slip and is concentrated within a depth range of 7–16 km, which explains the significant uplift near the epicenter observed by both the Sentinel-1 ascending and descending In SAR data. Moreover, the teleseismic array waveforms indicate a northwest propagating rupture with an overall slow rupture velocity of~1.91 km/s(AK array) or 1.01 km/s(AU array). 展开更多
关键词 Jishishan earthquake Rupture property Space imaging geodesy Finite fault inversion Back-projection method
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A stable implicit nodal integration-based particle finite element method(N-PFEM)for modelling saturated soil dynamics 被引量:1
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作者 Liang Wang Xue Zhang +1 位作者 Jingjing Meng Qinghua Lei 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2172-2183,共12页
In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated soils.Our approach incorporates the nodal integration technique into a gene... In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated soils.Our approach incorporates the nodal integration technique into a generalised Hellinger-Reissner(HR)variational principle,creating an implicit PFEM formulation.To mitigate the volumetric locking issue in low-order elements,we employ a node-based strain smoothing technique.By discretising field variables at the centre of smoothing cells,we achieve nodal integration over cells,eliminating the need for sophisticated mapping operations after re-meshing in the PFEM.We express the discretised governing equations as a min-max optimisation problem,which is further reformulated as a standard second-order cone programming(SOCP)problem.Stresses,pore water pressure,and displacements are simultaneously determined using the advanced primal-dual interior point method.Consequently,our numerical model offers improved accuracy for stresses and pore water pressure compared to the displacement-based PFEM formulation.Numerical experiments demonstrate that the N-PFEM efficiently captures both transient and long-term hydro-mechanical behaviour of saturated soils with high accuracy,obviating the need for stabilisation or regularisation techniques commonly employed in other nodal integration-based PFEM approaches.This work holds significant implications for the development of robust and accurate numerical tools for studying saturated soil dynamics. 展开更多
关键词 Particle finite element method Nodal integration Dynamic saturated media Second-order cone programming(SOCP)
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Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries 被引量:1
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作者 N.IQBAL J.CHOI +2 位作者 S.F.SHAH C.LEE S.LEE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第6期947-962,共16页
A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDO... A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more homogeneously.Besides,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress mitigation.This paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels. 展开更多
关键词 lithium-ion battery(LIB) polycrystalline particle COATING finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)
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Pressure generation under deformation in a large-volume press
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作者 Saisai Wang Xinyu Zhao +8 位作者 Kuo Hu Bingtao Feng Xuyuan Hou Yiming Zhang Shucheng Liu Yuchen Shang Zhaodong Liu Mingguang Yao Bingbing Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期622-626,共5页
Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challeng... Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challenging and thereby causes relatively large pressure uncertainties in deformation experiments,resulting in the synthesis of complex multiphase materials.Here,pressure generations of three types of deformation assemblies were well calibrated in a Walker-type largevolume press(LVP)by electrical resistance measurements combined with finite element simulations(FESs).Hard Al_(2)O_(3) or diamond pistons in shear and uniaxial deformation assemblies significantly increase the efficiency of pressure generation compared with the conventional quasi-hydrostatic assembly.The uniaxial deformation assembly using flat diamond pistons possesses the highest efficiency in these deformation assemblies.This finding is further confirmed by stress distribution analysis based on FESs.With this deformation assembly,we found shear can effectively promote the transformation of C60 into diamond under high pressure and realized the synthesis of phase-pure diamond at relatively moderate pressure and temperature conditions.The present developed techniques will help improve pressure efficiencies in LVP and explore the new physical and chemical properties of materials under deformation in both science and technology. 展开更多
关键词 shear/uniaxial DEFORMATION PRESSURE calibration finite element simulations large- VOLUME PRESS high PRESSURE
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Finite Size Effect on Gluon Dissociation of J/ψin Relativistic Heavy Ion Collisions
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作者 Jingjing Wang Baoyi Chen Yunpeng Liu 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第10期38-42,共5页
Thermal quantities,including the the entropy density and gluon spectrum,of quark matter within a box that is finite in the longitudinal direction are calculated using a bag model.Under the assumption of entropy conser... Thermal quantities,including the the entropy density and gluon spectrum,of quark matter within a box that is finite in the longitudinal direction are calculated using a bag model.Under the assumption of entropy conservation,the corresponding gluon dissociation rate of J/ψis studied.It reaches a maximum at a certain longitudinal size𝐿m,below which the suppression is weak even if the temperature becomes higher than that without the finite size effect,and above which the dissociation rate approaches to the thermodynamic limit gradually with increasing longitudinal size of the fireball. 展开更多
关键词 ENTROPY DISSOCIATION FINITE
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Profiling Electronic and Phononic Band Structures of Semiconductors at Finite Temperatures: Methods and Applications
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作者 张燮 康俊 魏苏淮 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第2期57-68,共12页
Semiconductor devices are often operated at elevated temperatures that are well above zero Kelvin,which is the temperature in most first-principles density functional calculations.Computational approaches to com-putin... Semiconductor devices are often operated at elevated temperatures that are well above zero Kelvin,which is the temperature in most first-principles density functional calculations.Computational approaches to com-puting and understanding the properties of semiconductors at finite temperatures are thus in critical demand.In this review,we discuss the recent progress in computationally assessing the electronic and phononic band structures of semiconductors at finite temperatures.As an emerging semiconductor with particularly strong temperature-induced renormalization of the electronic and phononic band structures,halide perovskites are used as a representative example to demonstrate how computational advances may help to understand the band struc-tures at elevated temperatures.Finally,we briefly illustrate the remaining computational challenges and outlook promising research directions that may help to guide future research in this field. 展开更多
关键词 FINITE struc DIRECTIONS
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Recurrent Neural Network Inspired Finite-Time Control Design
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作者 Jianan Liu Shihua Li Rongjie Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1527-1529,共3页
Dear Editor,This letter is concerned with the role of recurrent neural networks(RNNs)on the controller design for a class of nonlinear systems.Inspired by the architectures of RNNs,the system states are stacked accord... Dear Editor,This letter is concerned with the role of recurrent neural networks(RNNs)on the controller design for a class of nonlinear systems.Inspired by the architectures of RNNs,the system states are stacked according to the dynamic along with time while the controller is represented as the neural network output.To build the bridge between RNNs and finite-time controller,a novel activation function is imposed on RNNs to drive the convergence of states at finite-time and propel the overall control process smoother.Rigorous stability proof is briefly provided for the convergence of the proposed finite-time controller.At last,a numerical simulation example is presented to illustrate the efficiency of the proposed strategy.Neural networks can be classified as static(feedforward)and dynamic(recurrent)nets[1].The former nets do not perform well in dealing with training data and using any information of the local data structure[2].In contrast to the feedforward neural networks,RNNs are constituted by high dimensional hidden states with dynamics. 展开更多
关键词 DYNAMICS FINITE PROOF
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THE SUPERCLOSENESS OF THE FINITE ELEMENT METHOD FOR A SINGULARLY PERTURBED CONVECTION-DIFFUSION PROBLEM ON A BAKHVALOV-TYPE MESH IN 2D
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作者 Chunxiao ZHANG Jin ZHANG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第4期1572-1593,共22页
For singularly perturbed convection-diffusion problems,supercloseness analysis of the finite element method is still open on Bakhvalov-type meshes,especially in the case of 2D.The difficulties arise from the width of ... For singularly perturbed convection-diffusion problems,supercloseness analysis of the finite element method is still open on Bakhvalov-type meshes,especially in the case of 2D.The difficulties arise from the width of the mesh in the layer adjacent to the transition point,resulting in a suboptimal estimate for convergence.Existing analysis techniques cannot handle these difficulties well.To fill this gap,here a novel interpolation is designed delicately for the smooth part of the solution,bringing about the optimal supercloseness result of almost order 2 under an energy norm for the finite element method.Our theoretical result is uniform in the singular perturbation parameterεand is supported by the numerical experiments. 展开更多
关键词 singularly perturbed CONVECTION-DIFFUSION finite element method SUPERCLOSENESS Bakhvalov-type mesh
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Natural Convection and Irreversibility of Nanofluid Due to Inclined Magnetohydrodynamics(MHD)Filled in a Cavity with Y-Shape Heated Fin:FEM Computational
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作者 Afraz Hussain Majeed Rashid Mahmood +3 位作者 Sayed M.Eldin Imran Saddique S.Saleem Muhammad Jawad 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1505-1519,共15页
This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin andmagnetic field.The temperature is constant on the Y-shaped fin,insulating the topwall while th... This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin andmagnetic field.The temperature is constant on the Y-shaped fin,insulating the topwall while the remaining walls remain cold.All walls are subject to impermeability and non-slip conditions.The mathematical modeling of the problem is demonstrated by the continuity,momentum,and energy equations incorporating the inclined magnetic field.For elucidating the flow characteristics Finite ElementMethod(FEM)is implemented using stable FE pair.A hybrid fine mesh is used for discretizing the domain.Velocity and thermal plots concerning parameters are drawn.In addition,a detailed discussion regarding generation energy by monitoring changes in magnetic,viscous,total,and thermal irreversibility is provided.In addition,line graphs are created for the u and v components of the velocity profile to predict the flow behavior.Current simulations assume the dimensionless representative of magnetic field Hartmann number Ha between 0 and 100 and a magnetic field inclination between 0 and 90 degrees.A constant 4% volume proportion of nanoparticles is employed throughout all scenarios. 展开更多
关键词 Finite element method nanomaterials entropy MHD square cavity Y-fin
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On entire solutions of some Fermat type differential-difference equations
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作者 LONG Jian-ren QIN Da-zhuan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第1期69-88,共20页
On one hand,we study the existence of transcendental entire solutions with finite order of the Fermat type difference equations.On the other hand,we also investigate the existence and growth of solutions of nonlinear ... On one hand,we study the existence of transcendental entire solutions with finite order of the Fermat type difference equations.On the other hand,we also investigate the existence and growth of solutions of nonlinear differential-difference equations.These results extend and improve some previous in[5,14]. 展开更多
关键词 entire solutions differential-difference equations EXISTENCE finite order
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Effect of Size Change on Mechanical Properties of Monolayer Arsenene
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作者 郭娟 刘贵立 孙震宇 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期206-212,共7页
The Young's modulus, shear modulus and Poisson's ratio of monolayer arsenene with different sizes were calculated by finite element method, so as to explore the influence of dimension and orientation on the me... The Young's modulus, shear modulus and Poisson's ratio of monolayer arsenene with different sizes were calculated by finite element method, so as to explore the influence of dimension and orientation on the mechanical properties of monolayer arsenene. The calculation results show that the small size has a significant effect on the mechanical properties of the monolayer arsenene. The smaller the size, the larger the Young's modulus and Poisson's ratio of the monolayer arsenene. The size change has a great influence on the Young's modulus of the arsenene handrail direction, and the Young's modulus of the zigzag direction is not sensitive to the size change. Similarly, the size change has a significant effect on the shear modulus of arsenene in the handrail direction, while the shear modulus in the zigzag direction has no significant effect on its size change. For the Poisson's ratio, the situation is just the opposite, and the effect of the size change on the Poisson's ratio of the arsenene zigzag direction is greater than that of the handrail direction. 展开更多
关键词 finite element method arsenene size change mechanical properties
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Tuning microstructures of TC4 ELI to improve explosion resistance
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作者 Changle Zhang Yangwei Wang +6 位作者 Lin Wang Zixuan Ning Guoju Li Dongping Chen Zhi-Wei Yan Yuchen Song Xucai Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期78-99,共22页
A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion resistance.However,there is limited investigation on tuning microstructures of TC4 ELI to impr... A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion resistance.However,there is limited investigation on tuning microstructures of TC4 ELI to improve explosion resistance.Moreover,the current challenge is quantifying microstructural changes'effects on explosion resistance and incorporating microstructural changes into finite element models.This work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism,and find a suitable method to incorporate microstructural changes into finite element models.In this work,we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element modeling.The Johnson-Cook(JC)constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element models.Because of the heat treatment,one plate has equiaxed microstructure and the other has bimodal microstructure.The convex of the plate after the explosion has a quadratic relationship with the charge mass,and the simulation results demonstrate high reliability,with the error less than 17.5%.Therefore,it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion resistance.The bimodal target exhibits excellent deformation resistance.The response of bimodal microstructure to the shock wave may be more intense under explosive loading.The well-coordinated structure of the bimodal target enhances its resistance to deformation. 展开更多
关键词 MICROSTRUCTURE Finite element modelling Parameter optimization Failure characteristics Explosion resistance
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Study on Dynamic Mechanical Behavior of Al-Mg-Si Alloy
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作者 陶小旺 LIU Jibo +3 位作者 LIU Xianbin CHEN Jianbin WANG Yonggang 汪小锋 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期454-462,共9页
The dynamic mechanical behavior of Al-Mg-Si alloy was investigated under different strain rates by mechanical property and microstructure characterization,constitutive behavior analysis and numerical simulation in the... The dynamic mechanical behavior of Al-Mg-Si alloy was investigated under different strain rates by mechanical property and microstructure characterization,constitutive behavior analysis and numerical simulation in the present study.As the strain rate increases,the yield strength,ultimate tensile strength and elongation increase first,then remain almost constant,and finally increase.The alloy always exhibits a typical ductile fracture mode,not depending on the strain rate.However,as the strain rate increases,the number of dimples gradually increases.Tensile deformation can refine grains,however,the grain structure is slightly affected by the strain rate.An optimized Johnson-Cook constitutive equation was used to describe the mechanical behavior and obtained by fitting the true stress-strain curves.The parameter C was described by a function related to the strain rate.The fitting true stress-strain curves by the JC model agree very well with the experimental true stress-strain curves.The true stress-strain curves calculated by the finite element numerical simulation agree well with the experimental true stress-strain curves. 展开更多
关键词 Al-Mg-Si alloy strain rate mechanical property MICROSTRUCTURE Johnson-Cook model finite element simulation
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Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture
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作者 Mingjian Li Ping Yang Pengyang Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期2019-2034,共16页
The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain boundaries.However,the physical mechanism underlying this phenome... The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain boundaries.However,the physical mechanism underlying this phenomenon remains not fully understood.This study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal defects.This derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain energy.Subsequently,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain boundaries.This model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic deformation.The simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture. 展开更多
关键词 Ductile fracture VACANCY grain boundary MICROMECHANICAL finite element method
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Characteristics of the electromagnetic wave propagation in magnetized plasma sheath and practical method for blackout mitigation
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作者 吴翔 张珈珲 +1 位作者 董果香 石磊 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期489-499,共11页
“Magnetic window”is considered as an effective method to solve the communication blackout issue.COMSOL software package based on the finite element method is utilized to simulate the propagation of right-handed circ... “Magnetic window”is considered as an effective method to solve the communication blackout issue.COMSOL software package based on the finite element method is utilized to simulate the propagation of right-handed circularly polarized wave in the magnetized plasma sheath.We assume a double Gaussian model of electron density and an exponential attenuation model of magnetic field.The propagation characteristics of right-handed circularly polarized wave are analyzed by the observation of the reflected,transmitted and loss coefficient.The numerical results show that the propagation of right-handed circularly polarized wave in the magnetized plasma sheath varies for different incident angles,collision frequencies,non-uniform magnetic fields and non-uniform plasma densities.We notice that reducing the wave frequency can meet the propagation conditions of whistle mode in the weak magnetized plasma sheath.And the transmittance of whistle mode is less affected by the variation of the electron density and the collision frequency.It can be used as a communication window. 展开更多
关键词 magnetized plasma sheath communication blackout finite element incident angle whistler wave
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Preliminary electromagnetic analysis of the COOL blanket for CFETR
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作者 鲁帅领 马学斌 刘松林 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第1期101-108,共8页
The supercritical CO_(2)cOoled Lithium-Lead(COOL)blanket has been designed as one advanced blanket candidate for the Chinese Fusion Engineering Test Reactor(CFETR).This work focuses on the electromagnetic(EM)loads(Max... The supercritical CO_(2)cOoled Lithium-Lead(COOL)blanket has been designed as one advanced blanket candidate for the Chinese Fusion Engineering Test Reactor(CFETR).This work focuses on the electromagnetic(EM)loads(Maxwell force and Lorentz force)acting on the COOL blanket,which are important mechanical loads in further structural analysis of the COOL blanket.A 3D electromagnetic analysis is performed using the ANSYS finite element method to obtain EM loads on the COOL blanket in this study.At first,the magnetic scalar potential(MSP)method is used to obtain the magnetic field and the Maxwell force on the COOL blanket.Then,the magnetic vector potential(MVP)method is performed during a plasma disruption event to get the eddy current distribution.At last,a multi-step method is adopted for the calculation of the Lorentz force and the torque.The maximum Lorentz forces of inboard and outboard blanket structural components are 5624 kN and 2360 kN respectively. 展开更多
关键词 CFETR COOL blanket finite element analysis electromagnetic analysis
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裂纹加筋和缺口加筋对钢加筋板极限强度的影响
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作者 Musa Bahmani Fattaneh Morshedsolouk Mohammad Reza Khedmati 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第2期460-469,共10页
This paper numerically evaluates the effect of the crack position on the ultimate strength of stiffened panels.Imperfections such as notches and cracks in aged marine stiffened panels can reduce their ultimate strengt... This paper numerically evaluates the effect of the crack position on the ultimate strength of stiffened panels.Imperfections such as notches and cracks in aged marine stiffened panels can reduce their ultimate strength.To investigate the effect of crack length and position,a series of nonlinear finite element analyses were carried out and two cases were considered,i.e.,case 1 with thin stiffeners and case 2 with thick stiffeners.In both cases,the stiffeners have the same cross-section area.To have a basis for comparison,the intact panels were modeled as well.The cracks and notches were in the longitudinal and transverse direction and were assumed to be in the middle part of the panel.The cracks and notches were assumed to be through the thickness and there is neither crack propagation nor contact between crack faces.Based on the numerical results,longitudinal cracks affect the behavior of the stiffened panels in the postbuckling region.When the stiffeners are thinner,they buckle first and provide no reserved strength after plate buckling.Thus,cracks in the stiffeners do not affect the ultimate strength in the case of the thinner stiffeners.Generally,when stiffeners are thicker,they affect the postbuckling behavior more.In that case,cracks in the stiffeners affect the buckling and failure modes of the stiffened panels.The effect of notch was also studied.In contrast to the longitudinal crack in stiffeners,a notch in the stiffeners reduces the ultimate strength of the stiffened panel for both slender and thick stiffeners. 展开更多
关键词 Stiffened panels CRACK NOTCH Ultimate strength BUCKLING Nonlinear finite element method
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Analysis of mechanical strengths of extreme line casing joint considering geometric, material, and contact nonlinearities
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作者 Ji-Yun Zhang Chi Peng +4 位作者 Jian-Hong Fu Quan Cao Yu Su Jian-Yun Pang Zi-Qiang Yu 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1992-2004,共13页
To address the challenges associated with difficult casing running,limited annular space,and poor cementing quality in the completion of ultra-deep wells,the extreme line casing offers an effective solution over conve... To address the challenges associated with difficult casing running,limited annular space,and poor cementing quality in the completion of ultra-deep wells,the extreme line casing offers an effective solution over conventional casings.However,due to its smaller size,the joint strength of extreme line casing is reduced,which may cause failure when running in the hole.To address this issue,this study focuses on the CST-ZTΦ139.7 mm×7.72 mm extreme line casing and employs the elastic-plastic mechanics to establish a comprehensive analysis of the casing joint,taking into account the influence of geometric and material nonlinearities.A finite element model is developed to analyze the forces and deformations of the extreme line casing joint under axial tension and external collapse load.The model investigates the stress distribution of each thread tooth subjected to various tensile forces and external pressures.Additionally,the tensile strength and crushing strength of the extreme line casing joint are determined through both analytical and experimental approaches.The findings reveal that,under axial tensile load,the bearing surface of each thread tooth experiences uneven stress,with relatively high equivalent stress at the root of each thread tooth.The end thread teeth are valuable spots for failure.It is observed that the critical fracture axial load of thread decreases linearly with the increase of thread tooth sequence.Under external pressure,the circumferential stress is highest at the small end of the external thread,leading to yield deformation.The tensile strength of the joint obtained from the finite element model exhibits a relative error of less than 7%compared to the analytical and experimental values,proving the reliability of the finite element model.The tensile strength of the joint is 3091.9 k N.Moreover,in terms of anti-collapse capability,the joints demonstrate higher resistance to collapse compared to the casing body,which is consistent with the test results where the pipe body experiences collapse and failure while the joints remain intact during the experiment.The failure load of the casing body under external collapse pressure is 87.4 MPa.The present study provides a basic understanding of the mechanical strengths of extreme line casing joint. 展开更多
关键词 Extreme line casing Elastic-plastic mechanics Finite element analysis Tensile strength Collapse strength
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Modeling and characterization on electroplastic effect during dynamic deformation of 5182-O aluminum alloy
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作者 Hong-chun SHANG Song-chen WANG Yan-shan LOU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2455-2475,共21页
The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and characterized.The isothermal tensile test and electrically... The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and characterized.The isothermal tensile test and electrically-assisted isothermal tensile test were performed at the same temperature,and three typical models were further embedded in ABAQUS/Explicit for numerical simulation to illustrate the electroplastic effect.The results show that electric pulse reduces the deformation resistance but enhances the elongation greatly.The calibration accuracy of the proposed modified Lim−Huh model for highly nonlinear and coupled dynamic hardening behavior is not much improved compared to the modified Kocks−Mecking model.Moreover,the artificial neural network model is very suitable to describe the macromechenical response of materials under the coupling effect of different variables. 展开更多
关键词 machine learning aluminium alloy electroplastic effect coupling effect finite element analysis
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