<span style="font-family:Verdana;">Hydroplaning phenomenon is one of the major factors that must be considered to ensure safe driving on wet road surfaces. In this paper, the approach to numerical simu...<span style="font-family:Verdana;">Hydroplaning phenomenon is one of the major factors that must be considered to ensure safe driving on wet road surfaces. In this paper, the approach to numerical simulation of the physical hydroplaning characteristics using patterned tire is described. A detailed 3-D patterned tire model is constructed by in-house modeling program and the water flow is considered as incompressible. The complex tire material compositions are effectively modeled using composites, and rubber properties generalize the Mooney-Rivlin model. The finite element method (FEM) and the advanced finite volume method (FVM) are used for structural and for fluid-tire interaction analysis, respectively. Performance prediction of hydroplaning via coupling of computational fluid dynamics (CFD) and FEM has delivered a detailed insight into the local mechanisms and root causes of hydroplaning. Numerical examples were verified by comparing the experimental test results and it is confirmed to indicate similar correlation tendency and high reliability. The effect of driving velocity, pattern groove size, and pattern direction on hydroplaning phenomenon of tire is discussed and logical results were obtained.</span>展开更多
The freight logistics includes all the processes needed to supply industry,retailers and wholesalers and final customers with goods.Such processes generate a flow of goods that,in the global supply chain,mainly relies...The freight logistics includes all the processes needed to supply industry,retailers and wholesalers and final customers with goods.Such processes generate a flow of goods that,in the global supply chain,mainly relies on the activities carried out within worldwide container terminals.In this paper,the authors present a simulation model of a real container terminal.After some preliminary analyses,the simulation model is first used with Design of Experiments and Analysis of Variance to investigate the effects of different resources allocations(i.e.,number of forklifts and tractors)and some parameters(i.e.,inter-arrival times,container unloading time)on the container terminal performances in terms of total number of handled containers per day.Then,based on the results achieved through the Design of Experiments and Analysis of Variance,the simulation model is used with genetic algorithms to carry out a range allocation optimization on berth assignment to incoming ships and number of tractors serving each quay crane.The aim of the optimization is the minimization of the average time spent by each ship in the port area(decreasing,as consequence,costs and increasing service level provided to final customers).展开更多
Metal-stuffed B–C compounds with sodalite clathrate structure have captured increasing attention due to their predicted exceptional superconductivity above liquid nitrogen temperature at ambient pressure.However,by n...Metal-stuffed B–C compounds with sodalite clathrate structure have captured increasing attention due to their predicted exceptional superconductivity above liquid nitrogen temperature at ambient pressure.However,by neglecting the quantum lattice anharmonicity,the existing studiesmay result in an incomplete understanding of such a lightweight system.Here,using state-of-the-art ab initio methods incorporating quantum effects and machine learning potentials,we revisit the properties of a series of XYB_(6)C_(6)clathrates where X and Y are metals.Our findings show that ionic quantum and anharmonic effects can harden the E_(g)and E_(u)vibrational modes,enabling the dynamical stability of 15 materials previously considered unstable in the harmonic approximation,including materials with previously unreported (XY)^(1+)state,which is demonstrated here to be crucial to reach high critical temperatures.Further calculations based on the anisotropic Migdal-Eliashberg equation demonstrate that the T_(c)values for KRbB_(6)C_(6)and RbB_(3)C_(3)among these stabilized compounds are 102 and 115 Kat 0 and 15 GPa,respectively,both being higher than T_(c)of 92 K of KPbB_(6)C_(6)at the anharmonic level.These record-high T_(c)values,surpassing liquid nitrogen temperatures,emphasize the importance of anharmonic effects in stabilizing B-C clathrates with large electron-phonon coupling strength and advancing the search for high-T_(c)superconductivity at(near)ambient pressure.展开更多
Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated t...Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated the photogalvanic efect of semiconductors with time-reversal-invariant and spatial inversion symmetries using the quantum kinetic equation. We concluded that the integral of the symmetric(antisymmetric) part of quantum geometric tensor on the equal energy surface in momentum space, satisfying the resonance condition, is related to the generation rate of carriers in semiconductors under linearly(circularly) polarized light. Under additional bias voltage, the dc photocurrent is proportional to the bias voltage. Our study provided an alternative interpretation for the photogalvanic efect in the view of quantum geometric tensor. Additionally, it classified the intrinsic diference between linearly and circularly polarized optical fields.展开更多
文摘<span style="font-family:Verdana;">Hydroplaning phenomenon is one of the major factors that must be considered to ensure safe driving on wet road surfaces. In this paper, the approach to numerical simulation of the physical hydroplaning characteristics using patterned tire is described. A detailed 3-D patterned tire model is constructed by in-house modeling program and the water flow is considered as incompressible. The complex tire material compositions are effectively modeled using composites, and rubber properties generalize the Mooney-Rivlin model. The finite element method (FEM) and the advanced finite volume method (FVM) are used for structural and for fluid-tire interaction analysis, respectively. Performance prediction of hydroplaning via coupling of computational fluid dynamics (CFD) and FEM has delivered a detailed insight into the local mechanisms and root causes of hydroplaning. Numerical examples were verified by comparing the experimental test results and it is confirmed to indicate similar correlation tendency and high reliability. The effect of driving velocity, pattern groove size, and pattern direction on hydroplaning phenomenon of tire is discussed and logical results were obtained.</span>
文摘The freight logistics includes all the processes needed to supply industry,retailers and wholesalers and final customers with goods.Such processes generate a flow of goods that,in the global supply chain,mainly relies on the activities carried out within worldwide container terminals.In this paper,the authors present a simulation model of a real container terminal.After some preliminary analyses,the simulation model is first used with Design of Experiments and Analysis of Variance to investigate the effects of different resources allocations(i.e.,number of forklifts and tractors)and some parameters(i.e.,inter-arrival times,container unloading time)on the container terminal performances in terms of total number of handled containers per day.Then,based on the results achieved through the Design of Experiments and Analysis of Variance,the simulation model is used with genetic algorithms to carry out a range allocation optimization on berth assignment to incoming ships and number of tractors serving each quay crane.The aim of the optimization is the minimization of the average time spent by each ship in the port area(decreasing,as consequence,costs and increasing service level provided to final customers).
基金supported by the National Natural Science Foundation of China (Grant Nos. 12374008, 12022408, 12304013, 12374009, 12074138, 22131006, 52288102, and 52090024)the Interdisciplinary Integration and Innovation Project of JLU, Fundamental Research Funds for the Central Universities and the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT), open project from state key laboratory of superhard materials (No. 202408)+6 种基金College Student Innovation and Entrepreneurship Training Program (No. S202310183153)support from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation program (Grant Agreement No. 802533)the Spanish Ministry of Science and Innovation (Grant No. PID2022142861NA-I00)the Department of Education, Universities and Research of the Eusko Jaurlaritza and the University of the Basque Country UPV/EHU (Grant No. IT1527-22)Simons Foundation through the Collaboration on New Frontiers in Superconductivity (Grant No. SFI-MPS-NFS-00006741-10)Y.-W.F. acknowledges the Extraordinary Grant of CSIC (No. 2025ICT122)the IKUR Strategy-High Performance Computing and Artificial Intelligence (HPC&AI) 2025-2026 of the Department of Science, Universities and Innovation of the Basque Government. Technical and human support provided by DIPC Supercomputing Center is gratefully acknowledged.
文摘Metal-stuffed B–C compounds with sodalite clathrate structure have captured increasing attention due to their predicted exceptional superconductivity above liquid nitrogen temperature at ambient pressure.However,by neglecting the quantum lattice anharmonicity,the existing studiesmay result in an incomplete understanding of such a lightweight system.Here,using state-of-the-art ab initio methods incorporating quantum effects and machine learning potentials,we revisit the properties of a series of XYB_(6)C_(6)clathrates where X and Y are metals.Our findings show that ionic quantum and anharmonic effects can harden the E_(g)and E_(u)vibrational modes,enabling the dynamical stability of 15 materials previously considered unstable in the harmonic approximation,including materials with previously unreported (XY)^(1+)state,which is demonstrated here to be crucial to reach high critical temperatures.Further calculations based on the anisotropic Migdal-Eliashberg equation demonstrate that the T_(c)values for KRbB_(6)C_(6)and RbB_(3)C_(3)among these stabilized compounds are 102 and 115 Kat 0 and 15 GPa,respectively,both being higher than T_(c)of 92 K of KPbB_(6)C_(6)at the anharmonic level.These record-high T_(c)values,surpassing liquid nitrogen temperatures,emphasize the importance of anharmonic effects in stabilizing B-C clathrates with large electron-phonon coupling strength and advancing the search for high-T_(c)superconductivity at(near)ambient pressure.
基金supported by the National Natural Science Foundation of China (Grant No. 11604068)supported by the National Key R&D Program of China (Grant No. 2017YFA0305500)+1 种基金Natural Science Foundation of Jiangsu Province (Grant No. BK20200071)supported by MEXT via “Exploratory Challenge on Post-K Computer”(Frontiers of Basic Science:Challenging the Limits)。
文摘Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated the photogalvanic efect of semiconductors with time-reversal-invariant and spatial inversion symmetries using the quantum kinetic equation. We concluded that the integral of the symmetric(antisymmetric) part of quantum geometric tensor on the equal energy surface in momentum space, satisfying the resonance condition, is related to the generation rate of carriers in semiconductors under linearly(circularly) polarized light. Under additional bias voltage, the dc photocurrent is proportional to the bias voltage. Our study provided an alternative interpretation for the photogalvanic efect in the view of quantum geometric tensor. Additionally, it classified the intrinsic diference between linearly and circularly polarized optical fields.
