The celebrated antiferromagnetic(AFM) phase transition was realized in a most recent optical lattice experiment for the 3D fermionic Hubbard model [Shao et al. Nature 632 267(2024)]. Despite this important progress, i...The celebrated antiferromagnetic(AFM) phase transition was realized in a most recent optical lattice experiment for the 3D fermionic Hubbard model [Shao et al. Nature 632 267(2024)]. Despite this important progress, it was observed that the AFM structure factor(and also the critical entropy) reaches its maximum at an interaction strength U/t■11.75, which is significantly larger than the theoretical prediction of U/t■8. Here,we resolve this discrepancy by studying the interplay between the thermal entropy, density disorder, and antiferromagnetism in the half-filled 3D Hubbard model, using numerically exact auxiliary-field quantum Monte Carlo simulations. We have achieved an accurate entropy phase diagram, enabling us to simulate arbitrary entropy path on the temperature-interaction plane and track experimental parameters effectively. We find that above the discrepancy can be quantitatively explained by the entropy increase associated with increasing interaction strength in experiments, and together with the lattice density disorder present in the experimental setup. We further investigate the entropy dependence of double occupancy and predict universal behaviors that could serve as valuable probes in future optical lattice experiments.展开更多
The Casimir force between a perfectly conducting wall and a dielectric wall in a cavity comprising a transparent dielectric with output coupling is investigated. By using furl quantum theory, we obtain the analysis ex...The Casimir force between a perfectly conducting wall and a dielectric wall in a cavity comprising a transparent dielectric with output coupling is investigated. By using furl quantum theory, we obtain the analysis expression of the force, which shows that the interaction of the two walls in this system is always repulsive. And the value of the Casimir force varies with the field amplitude reflectivity and the cavity size.展开更多
To achieve optimal configuration of switching devices in a power distribution system,this paper proposes a repulsive firefly algorithm-based optimal switching device placement method.In this method,the influence of te...To achieve optimal configuration of switching devices in a power distribution system,this paper proposes a repulsive firefly algorithm-based optimal switching device placement method.In this method,the influence of territorial repulsion during firefly courtship is considered.The algorithm is practically applied to optimize the position and quantity of switching devices,while avoiding its convergence to the local optimal solution.The experimental simulation results have showed that the proposed repulsive firefly algorithm is feasible and effective,with satisfying global search capability and convergence speed,holding potential applications in setting value calculation of relay protection and distribution network automation control.展开更多
Spinal cord injury（SCI）leads to permanent disability with motor and sensory dysfunctions.The mature mammalian central nervous system（CNS）possesses a limited capacity to regenerate/regrow after injury.
The combination of ultrahigh strength and excellent ductility of nanotwinned materials is rooted in the interaction between dislocations and twin boundaries(TBs).Quantifying the interaction between TBs and dislocation...The combination of ultrahigh strength and excellent ductility of nanotwinned materials is rooted in the interaction between dislocations and twin boundaries(TBs).Quantifying the interaction between TBs and dislocations not only offers fresh perspectives of designing materials with high strength and ductility,but also becomes the cornerstone of multiscale modeling of materials with TBs.In this work,an atomcontinuum coupling model was adopted to quantitatively investigate the interaction between dislocations and TBs.The simulation shows that the dislocation-TB interaction is much weaker than the interaction between dislocations at the same distance.Simulation of the early stage of dislocation pileups further verifies that the experimentally observed repulsive forces are essentially from the dislocations or kink-like steps on TBs.The interaction between TBs and dislocations with different Burgers vectors was demonstrated referring to the elastic theory of dislocations.With the intrinsic interaction between dislocations and TBs being clarified,this work will promote further development of the multiscale simulation methods,such as discrete dislocation dynamics or phase-field method,of materials with TBs by providing a quantitative description of the interactions between TBs and dislocations.展开更多
Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using ...Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using standard parametrizations. The investigation is based on Density Functional Theory and Tight Binding simulations. Our objective is not only to capture the values of the repulsive terms but also to efficiently reproduce the elastic properties and the forces. The elasticity values determine the rigidity of a material when some traction or load is applied on it. The pair-potential is based on an exponential term corrected by B-spline terms. In order to accelerate the computations, one uses a hierarchical optimization for the B-splines on different levels. Carbon graphenes constitute the configurations used in the simulations. We report on some results to show the efficiency of the B-splines on different levels.展开更多
Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using ...Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using standard parametrizations. The investigation is based on Density Functional Theory and Tight Binding simulations. Our objective is not only to capture the values of the repulsive terms but also to efficiently reproduce the elastic properties and the forces. The elasticity values determine the rigidity of a material when some traction or load is applied on it. The pair-potential is based on an exponential term corrected by B-spline terms. In order to accelerate the computations, one uses a hierarchical optimization for the B-splines on different levels. Carbon graphenes constitute the configurations used in the simulations. We report on some results to show the efficiency of the B-splines on different levels.展开更多
The bubble-bubble interaction(BBI)is attractive in most cases,but also could be repulsive.In the present study,three specific mechanisms of repulsive BBI are given.The great contribution to the repulsive BBI is derive...The bubble-bubble interaction(BBI)is attractive in most cases,but also could be repulsive.In the present study,three specific mechanisms of repulsive BBI are given.The great contribution to the repulsive BBI is derived from the large radius of the bubble catching the rebound point of the other bubble.For“elastic”bubble and“inelastic”bubble,with the increase of the phase shift between two bubbles,the BBI changes from attractive to repulsive,and the repulsion can be maintained.For both“elastic”bubbles,the BBI alternates between attractive interaction and repulsive interaction along the direction where the ambient radius of one of bubbles increases.For stimulating bubble and stimulated bubble,the BBI can be repulsive.Its property depends on the ambient radii of bubbles.In addition,the distribution of the radiation forces in ambient radius space shows that the BBI is sensitive to the size of bubble and is complex because the bubbles are not of the same size in an ultrasonic field.Finally,as the distance increases or decreases monotonically with time,the absolute value of the BBI decreases or increases,correspondingly.The BBI can oscillate not only in strength but also in polarity when the distance fluctuates with time.展开更多
The convective heat transfer coefficient and surface emissivity before and after flame occurrence on a wood specimen surface and the flame heat flux were estimated using the repulsive particle swarm optimization algor...The convective heat transfer coefficient and surface emissivity before and after flame occurrence on a wood specimen surface and the flame heat flux were estimated using the repulsive particle swarm optimization algorithm and cone heater test results. The cone heater specified in the ISO 5660 standards was used, and six cone heater heat fluxes were tested. Preservative-treated Douglas fir 21 mm in thickness was used as the wood specimen in the tests. This study confirmed that the surface temperature of the specimen, which was calculated using the convective heat transfer coefficient, surface emissivity and flame heat flux on the wood specimen by a repulsive particle swarm optimization algorithm, was consistent with the measured temperature. Considering the measurement errors in the surface temperature of the specimen, the applicability of the optimization method considered in this study was evaluated.展开更多
An accurate total energy calculation is essential in materials computation.To date,many tight-binding(TB)approaches based on parameterized hopping can produce electronic structures comparable to those obtained using f...An accurate total energy calculation is essential in materials computation.To date,many tight-binding(TB)approaches based on parameterized hopping can produce electronic structures comparable to those obtained using first-principles calculations.However,TB approaches still have limited applicability for determining material properties derived from the total energy.That is,the predictive power of the TB total energy is impaired by an inaccurate evaluation of the repulsive energy.The complexity associated with the parametrization of TB repulsive potentials is the weak link in this evaluation.In this study,we propose a new method for obtaining the pairwise TB repulsive potential for crystalline materials by employing the Chen-Möbius inversion theorem.We show that the TB-based phonon dispersions,calculated using the resulting repulsive potential,compare well with those obtained by first-principles calculations for various systems,including covalent and ionic bulk materials and twodimensional materials.The present approach only requires the first-principles total energy and TB electronic band energy as input and does not involve any parameters.This striking feature enables us to generate repulsive potentials programmatically.展开更多
Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for f...Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for further application of this process.Here,we regulate CO adsorption by forming a Nafion layer on the copper(Cu)electrode that is repulsive to OH^(-),contributing to enhanced selectivity of CO_(2) reduction to C_(2) products with the suppression of C 1 products.The operando Raman spectroscopy indicates that the local OH^(-)would adsorb on part of active sites and decrease the adsorption of CO.Therefore,the electrode with repulsive to OH^(-)can adjust the concentration of OH^(-),leading to the increased adsorption of CO and enhanced C–C coupling.This work shows that electrode design could be an effective strategy for improving the selectivity of CO_(2) reduction to multi-carbon products.展开更多
We consider a pair of Hamiltonians （H, H0） on L2（R^n）, where H0=p^2 -x^2 is a SchrSdinger operator with a repulsive potential, and H = H0＋V（x）. We show that, under suitable assumptions on the decay of the elect...We consider a pair of Hamiltonians （H, H0） on L2（R^n）, where H0=p^2 -x^2 is a SchrSdinger operator with a repulsive potential, and H = H0＋V（x）. We show that, under suitable assumptions on the decay of the electric potential, V is uniquely determined by the high energy limit of the scattering operator.展开更多
We put forward an enlightening view on repulsive force between antimatter:Antimatter repels each other,and the repulsive force is proportional to the product of their masses and inversely proportional to the square of...We put forward an enlightening view on repulsive force between antimatter:Antimatter repels each other,and the repulsive force is proportional to the product of their masses and inversely proportional to the square of the distance between them;There is no gravitational or anti-gravitational interaction between antimatter and positive matter.As their applications,we explain the Big Bang process in a new light.展开更多
The development of flexible zinc-ion batteries(ZIBs)faces a threeway trade-off among the ionic conductivity,Zn^(2+)mobility,and the electrochemical stability of hydrogel electrolytes.To address this challenge,we desig...The development of flexible zinc-ion batteries(ZIBs)faces a threeway trade-off among the ionic conductivity,Zn^(2+)mobility,and the electrochemical stability of hydrogel electrolytes.To address this challenge,we designed a cationic hydrogel named PAPTMA to holistically improve the reversibility of ZIBs.The long cationic branch chains in the polymeric matrix construct express pathways for rapid Zn^(2+)transport through an ionic repulsion mechanism,achieving simultaneously high Zn^(2+)transference number(0.79)and high ionic conductivity(28.7 mS cm−1).Additionally,the reactivity of water in the PAPTMA hydrogels is significantly inhibited,thus possessing a strong resistance to parasitic reactions.Mechanical characterization further reveals the superior tensile and adhesion strength of PAPTMA.Leveraging these properties,symmetric batteries employing PAPTMA hydrogel deliver exceeding 6000 h of reversible cycling at 1 mA cm^(−2) and maintain stable operation for 1000 h with a discharge of depth of 71%.When applied in 4×4 cm2 pouch cells with MnO_(2) as the cathode material,the device demonstrates remarkable operational stability and mechanical robustness through 150 cycles.This work presents an eclectic strategy for designing advanced hydrogels that combine high ionic conductivity,enhanced Zn^(2+)mobility,and strong resistance to parasitic reactions,paving the way for long-lasting flexible ZIBs.展开更多
In this study,we investigate the ef-ficacy of a hybrid parallel algo-rithm aiming at enhancing the speed of evaluation of two-electron repulsion integrals(ERI)and Fock matrix generation on the Hygon C86/DCU(deep compu...In this study,we investigate the ef-ficacy of a hybrid parallel algo-rithm aiming at enhancing the speed of evaluation of two-electron repulsion integrals(ERI)and Fock matrix generation on the Hygon C86/DCU(deep computing unit)heterogeneous computing platform.Multiple hybrid parallel schemes are assessed using a range of model systems,including those with up to 1200 atoms and 10000 basis func-tions.The findings of our research reveal that,during Hartree-Fock(HF)calculations,a single DCU ex-hibits 33.6 speedups over 32 C86 CPU cores.Compared with the efficiency of Wuhan Electronic Structure Package on Intel X86 and NVIDIA A100 computing platform,the Hygon platform exhibits good cost-effective-ness,showing great potential in quantum chemistry calculation and other high-performance scientific computations.展开更多
In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-bindi...In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-binding Hamiltonian including onsite Coulomb repulsion U,V,and spin-orbital couplingλ.The program is applied to Ba_(2)MgReO_(6)to fgure out the mechanism of structural instability and magnetic ordering.A comprehensive quadrupole phase diagram versus U and V withλ=0.28 eV is calculated.Our results demonstrate that the easy-plane anisotropy and the intersite Coulomb repulsion V must be considered to remove the orbital frustration.The increase of V to>20 meV would arrange quadrupole Q_(x^(2)-y^(2))antiparallelly,accompanied by small parallel Q_(3z)^(2)-r^(2),and stabilize Ba_(2)MgReO_(6)into the body-centered tetragonal structure.Such antiparallel Q_(x^(2)-y^(2))provides a new mechanism for the Dzyaloshinskii-Moriya interaction and gives rise to the canted antiferromagnetic(CAF)state along the[110]axis.Moreover,sizable octupoles such as O_(21)^(31),O_(21)^(33),O_(21)^(34)and O_(21)^(36)are discovered for the frst time in the CAF state.Our study not only provides a comprehensive understanding of the experimental results in Ba_(2)MgReO_(6),but also serves as a general and useful tool for the study of multipole physics in 5d compounds.展开更多
This paper deals with the problem of distributed formation tracking control and obstacle avoidance of multivehicle systems(MVSs)in complex obstacle-laden environments.The MVS under consideration consists of a leader v...This paper deals with the problem of distributed formation tracking control and obstacle avoidance of multivehicle systems(MVSs)in complex obstacle-laden environments.The MVS under consideration consists of a leader vehicle with an unknown control input and a group of follower vehicles,connected via a directed interaction topology,subject to simultaneous unknown heterogeneous nonlinearities and external disturbances.The central aim is to achieve effective and collisionfree formation tracking control for the nonlinear and uncertain MVS with obstacles encountered in formation maneuvering,while not demanding global information of the interaction topology.Toward this goal,a radial basis function neural network is used to model the unknown nonlinearity of vehicle dynamics in each vehicle and repulsive potentials are employed for obstacle avoidance.Furthermore,a scalable distributed adaptive formation tracking control protocol with a built-in obstacle avoidance mechanism is developed.It is proved that,with the proposed protocol,the resulting formation tracking errors are uniformly ultimately bounded and obstacle collision avoidance is guaranteed.Comprehensive simulation results are elaborated to substantiate the effectiveness and the promising collision avoidance performance of the proposed scalable adaptive formation control approach.展开更多
Nanoparticles with competitive interactions in solution can aggregate into complex structures. In this work, the synergistic self-assembles of binary particles with electrostatic and van der Waals interactions are stu...Nanoparticles with competitive interactions in solution can aggregate into complex structures. In this work, the synergistic self-assembles of binary particles with electrostatic and van der Waals interactions are studied with the particle Langevin dynamics simulation using a simple coarse-grained particle model. Various aggregations such as spherical, stacking-disk and tube structures are observed by varying the particles size and the interaction strength. The aggregation structures are explained with the packing theories of amphiphilic molecules in solution and dibolck copolymers in bulk. When the opposite ions are introduced into solution, the distribution of structures in the phase diagram appears an obvious offset. The simulation result is helpful to deeply understand the formation mechanism of complex nanostructures of multicomponent particles in solution.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12247103,12204377,12275263)the Quantum Science and Technology National Science and Technology Major Project (Grant No.2021ZD0301900)+1 种基金the Natural Science Foundation of Fujian province of China (Grant No.2023J02032)the Youth Innovation Team of Shaanxi Universities。
文摘The celebrated antiferromagnetic(AFM) phase transition was realized in a most recent optical lattice experiment for the 3D fermionic Hubbard model [Shao et al. Nature 632 267(2024)]. Despite this important progress, it was observed that the AFM structure factor(and also the critical entropy) reaches its maximum at an interaction strength U/t■11.75, which is significantly larger than the theoretical prediction of U/t■8. Here,we resolve this discrepancy by studying the interplay between the thermal entropy, density disorder, and antiferromagnetism in the half-filled 3D Hubbard model, using numerically exact auxiliary-field quantum Monte Carlo simulations. We have achieved an accurate entropy phase diagram, enabling us to simulate arbitrary entropy path on the temperature-interaction plane and track experimental parameters effectively. We find that above the discrepancy can be quantitatively explained by the entropy increase associated with increasing interaction strength in experiments, and together with the lattice density disorder present in the experimental setup. We further investigate the entropy dependence of double occupancy and predict universal behaviors that could serve as valuable probes in future optical lattice experiments.
基金Supported by the National Natural Science Foundation of China under Grant Nos.1117504411105021+2 种基金and 11204028the Natural Science Foundation of Jilin Provinceunder Grant No.201115007
文摘The Casimir force between a perfectly conducting wall and a dielectric wall in a cavity comprising a transparent dielectric with output coupling is investigated. By using furl quantum theory, we obtain the analysis expression of the force, which shows that the interaction of the two walls in this system is always repulsive. And the value of the Casimir force varies with the field amplitude reflectivity and the cavity size.
基金supported by the State Grid Science and Technology Project “Research on Technology System and Applications Scenarios of Artificial Intelligence in Power System” (No. SGZJ0000KXJS1800435)Key Technology Project of State Grid Shanghai Municipal Electric Power Company “Research and demonstration of Shanghai power grid reliability analysis platform”Key Technology Project of China Electric Power Research Institute “Research on setting calculation technology of power grid phase protection based on Artificial Intelligence” (JB83-19-007)
文摘To achieve optimal configuration of switching devices in a power distribution system,this paper proposes a repulsive firefly algorithm-based optimal switching device placement method.In this method,the influence of territorial repulsion during firefly courtship is considered.The algorithm is practically applied to optimize the position and quantity of switching devices,while avoiding its convergence to the local optimal solution.The experimental simulation results have showed that the proposed repulsive firefly algorithm is feasible and effective,with satisfying global search capability and convergence speed,holding potential applications in setting value calculation of relay protection and distribution network automation control.
基金supported by the Strategic Research Program for Brain Sciences from the Japan Agency for Medical ResearchDevelopment,and by the Grants-in-Aid for Scientific Research in Innovation Areas
文摘Spinal cord injury（SCI）leads to permanent disability with motor and sensory dysfunctions.The mature mammalian central nervous system（CNS）possesses a limited capacity to regenerate/regrow after injury.
基金financially supported by the Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project(Grant No.HZQB-KCZYB-2020030)the National Natural Science Foundation of China(Grant Nos.12072062,11772082,12072061)+2 种基金the Liaoning Revitalization Talents Program(Grant No.XLYC1807193)Key Research and Development Project of Liaoning Province(Grant No.2020JH2/10500003)the Fundamental Research Funds for the Central Universities(Grant No.DUT20LAB203)。
文摘The combination of ultrahigh strength and excellent ductility of nanotwinned materials is rooted in the interaction between dislocations and twin boundaries(TBs).Quantifying the interaction between TBs and dislocations not only offers fresh perspectives of designing materials with high strength and ductility,but also becomes the cornerstone of multiscale modeling of materials with TBs.In this work,an atomcontinuum coupling model was adopted to quantitatively investigate the interaction between dislocations and TBs.The simulation shows that the dislocation-TB interaction is much weaker than the interaction between dislocations at the same distance.Simulation of the early stage of dislocation pileups further verifies that the experimentally observed repulsive forces are essentially from the dislocations or kink-like steps on TBs.The interaction between TBs and dislocations with different Burgers vectors was demonstrated referring to the elastic theory of dislocations.With the intrinsic interaction between dislocations and TBs being clarified,this work will promote further development of the multiscale simulation methods,such as discrete dislocation dynamics or phase-field method,of materials with TBs by providing a quantitative description of the interactions between TBs and dislocations.
文摘Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using standard parametrizations. The investigation is based on Density Functional Theory and Tight Binding simulations. Our objective is not only to capture the values of the repulsive terms but also to efficiently reproduce the elastic properties and the forces. The elasticity values determine the rigidity of a material when some traction or load is applied on it. The pair-potential is based on an exponential term corrected by B-spline terms. In order to accelerate the computations, one uses a hierarchical optimization for the B-splines on different levels. Carbon graphenes constitute the configurations used in the simulations. We report on some results to show the efficiency of the B-splines on different levels.
文摘Quantum energies which are used in applications are usually composed of repulsive and attractive terms. The objective of this study is to use an accurate and efficient fitting of the repulsive energy instead of using standard parametrizations. The investigation is based on Density Functional Theory and Tight Binding simulations. Our objective is not only to capture the values of the repulsive terms but also to efficiently reproduce the elastic properties and the forces. The elasticity values determine the rigidity of a material when some traction or load is applied on it. The pair-potential is based on an exponential term corrected by B-spline terms. In order to accelerate the computations, one uses a hierarchical optimization for the B-splines on different levels. Carbon graphenes constitute the configurations used in the simulations. We report on some results to show the efficiency of the B-splines on different levels.
基金supported by the National Natural Science Foundation of China(Grant Nos.11574150 and 12074185).
文摘The bubble-bubble interaction(BBI)is attractive in most cases,but also could be repulsive.In the present study,three specific mechanisms of repulsive BBI are given.The great contribution to the repulsive BBI is derived from the large radius of the bubble catching the rebound point of the other bubble.For“elastic”bubble and“inelastic”bubble,with the increase of the phase shift between two bubbles,the BBI changes from attractive to repulsive,and the repulsion can be maintained.For both“elastic”bubbles,the BBI alternates between attractive interaction and repulsive interaction along the direction where the ambient radius of one of bubbles increases.For stimulating bubble and stimulated bubble,the BBI can be repulsive.Its property depends on the ambient radii of bubbles.In addition,the distribution of the radiation forces in ambient radius space shows that the BBI is sensitive to the size of bubble and is complex because the bubbles are not of the same size in an ultrasonic field.Finally,as the distance increases or decreases monotonically with time,the absolute value of the BBI decreases or increases,correspondingly.The BBI can oscillate not only in strength but also in polarity when the distance fluctuates with time.
基金support from the research fund of the National Emergency Management Agency.(NEMA- Infra-2014-103)
文摘The convective heat transfer coefficient and surface emissivity before and after flame occurrence on a wood specimen surface and the flame heat flux were estimated using the repulsive particle swarm optimization algorithm and cone heater test results. The cone heater specified in the ISO 5660 standards was used, and six cone heater heat fluxes were tested. Preservative-treated Douglas fir 21 mm in thickness was used as the wood specimen in the tests. This study confirmed that the surface temperature of the specimen, which was calculated using the convective heat transfer coefficient, surface emissivity and flame heat flux on the wood specimen by a repulsive particle swarm optimization algorithm, was consistent with the measured temperature. Considering the measurement errors in the surface temperature of the specimen, the applicability of the optimization method considered in this study was evaluated.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274035,and 11874088)supported by the Fundamental Research Funds for the Central Universities。
文摘An accurate total energy calculation is essential in materials computation.To date,many tight-binding(TB)approaches based on parameterized hopping can produce electronic structures comparable to those obtained using first-principles calculations.However,TB approaches still have limited applicability for determining material properties derived from the total energy.That is,the predictive power of the TB total energy is impaired by an inaccurate evaluation of the repulsive energy.The complexity associated with the parametrization of TB repulsive potentials is the weak link in this evaluation.In this study,we propose a new method for obtaining the pairwise TB repulsive potential for crystalline materials by employing the Chen-Möbius inversion theorem.We show that the TB-based phonon dispersions,calculated using the resulting repulsive potential,compare well with those obtained by first-principles calculations for various systems,including covalent and ionic bulk materials and twodimensional materials.The present approach only requires the first-principles total energy and TB electronic band energy as input and does not involve any parameters.This striking feature enables us to generate repulsive potentials programmatically.
基金This work was supported by the following projects:INTERNATIONAL COOPERATION Projects of the Ministry of Science and Technology(2014DFE60170)the Strategic Japanese-Swiss Science and Technology Program from the Swiss National Science Foundation(project No.IZJSZ2_180176)+4 种基金the Sino-Swiss Science and Technology Cooperation(SSSTC)2016 project from the Swiss National Science Foundation(project No.IZLCZ2_170294)the National Natural Science Foundation of China(Grant No.61674084)the Overseas Expertise Introduction Project for DisciplineInnovation of Higher Education of China(Grant No.B16027)Tianjin Science and Technology Project(Grant No.18ZXJMTG00220)the Fundamental Research Fund for the Central Universities of China.
文摘Electrochemical CO_(2) reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels.However,the selectivity of value-added multi-carbon products remains poor for further application of this process.Here,we regulate CO adsorption by forming a Nafion layer on the copper(Cu)electrode that is repulsive to OH^(-),contributing to enhanced selectivity of CO_(2) reduction to C_(2) products with the suppression of C 1 products.The operando Raman spectroscopy indicates that the local OH^(-)would adsorb on part of active sites and decrease the adsorption of CO.Therefore,the electrode with repulsive to OH^(-)can adjust the concentration of OH^(-),leading to the increased adsorption of CO and enhanced C–C coupling.This work shows that electrode design could be an effective strategy for improving the selectivity of CO_(2) reduction to multi-carbon products.
文摘We consider a pair of Hamiltonians （H, H0） on L2（R^n）, where H0=p^2 -x^2 is a SchrSdinger operator with a repulsive potential, and H = H0＋V（x）. We show that, under suitable assumptions on the decay of the electric potential, V is uniquely determined by the high energy limit of the scattering operator.
文摘We put forward an enlightening view on repulsive force between antimatter:Antimatter repels each other,and the repulsive force is proportional to the product of their masses and inversely proportional to the square of the distance between them;There is no gravitational or anti-gravitational interaction between antimatter and positive matter.As their applications,we explain the Big Bang process in a new light.
基金financially supported by the General Research Fund(CityU 11315622 and CityU 11310123)National Natural Science Foundation(NSFC 52372229 and NSFC 52172241)+3 种基金Green Tech Fund(GTF202220105)Guangdong Basic and Applied Basic Research Foundation(2024A1515011008)City University of Hong Kong(No.9020002)the Shenzhen Research Institute of City University of Hong Kong.
文摘The development of flexible zinc-ion batteries(ZIBs)faces a threeway trade-off among the ionic conductivity,Zn^(2+)mobility,and the electrochemical stability of hydrogel electrolytes.To address this challenge,we designed a cationic hydrogel named PAPTMA to holistically improve the reversibility of ZIBs.The long cationic branch chains in the polymeric matrix construct express pathways for rapid Zn^(2+)transport through an ionic repulsion mechanism,achieving simultaneously high Zn^(2+)transference number(0.79)and high ionic conductivity(28.7 mS cm−1).Additionally,the reactivity of water in the PAPTMA hydrogels is significantly inhibited,thus possessing a strong resistance to parasitic reactions.Mechanical characterization further reveals the superior tensile and adhesion strength of PAPTMA.Leveraging these properties,symmetric batteries employing PAPTMA hydrogel deliver exceeding 6000 h of reversible cycling at 1 mA cm^(−2) and maintain stable operation for 1000 h with a discharge of depth of 71%.When applied in 4×4 cm2 pouch cells with MnO_(2) as the cathode material,the device demonstrates remarkable operational stability and mechanical robustness through 150 cycles.This work presents an eclectic strategy for designing advanced hydrogels that combine high ionic conductivity,enhanced Zn^(2+)mobility,and strong resistance to parasitic reactions,paving the way for long-lasting flexible ZIBs.
基金supported by the National Natural Science Foundation of China(No.22373112 to Ji Qi,No.22373111 and 21921004 to Minghui Yang)GH-fund A(No.202107011790)。
文摘In this study,we investigate the ef-ficacy of a hybrid parallel algo-rithm aiming at enhancing the speed of evaluation of two-electron repulsion integrals(ERI)and Fock matrix generation on the Hygon C86/DCU(deep computing unit)heterogeneous computing platform.Multiple hybrid parallel schemes are assessed using a range of model systems,including those with up to 1200 atoms and 10000 basis func-tions.The findings of our research reveal that,during Hartree-Fock(HF)calculations,a single DCU ex-hibits 33.6 speedups over 32 C86 CPU cores.Compared with the efficiency of Wuhan Electronic Structure Package on Intel X86 and NVIDIA A100 computing platform,the Hygon platform exhibits good cost-effective-ness,showing great potential in quantum chemistry calculation and other high-performance scientific computations.
基金was supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1611200 and 2018YFA0307000)the National Natural Science Foundation of China(Grant Nos.12274154 and 12404182)。
文摘In order to calculate the multipoles in real materials with considerable intersite Coulomb interaction V,we develop a self-consistent program which starts from the frst-principles calculations to solve the tight-binding Hamiltonian including onsite Coulomb repulsion U,V,and spin-orbital couplingλ.The program is applied to Ba_(2)MgReO_(6)to fgure out the mechanism of structural instability and magnetic ordering.A comprehensive quadrupole phase diagram versus U and V withλ=0.28 eV is calculated.Our results demonstrate that the easy-plane anisotropy and the intersite Coulomb repulsion V must be considered to remove the orbital frustration.The increase of V to>20 meV would arrange quadrupole Q_(x^(2)-y^(2))antiparallelly,accompanied by small parallel Q_(3z)^(2)-r^(2),and stabilize Ba_(2)MgReO_(6)into the body-centered tetragonal structure.Such antiparallel Q_(x^(2)-y^(2))provides a new mechanism for the Dzyaloshinskii-Moriya interaction and gives rise to the canted antiferromagnetic(CAF)state along the[110]axis.Moreover,sizable octupoles such as O_(21)^(31),O_(21)^(33),O_(21)^(34)and O_(21)^(36)are discovered for the frst time in the CAF state.Our study not only provides a comprehensive understanding of the experimental results in Ba_(2)MgReO_(6),but also serves as a general and useful tool for the study of multipole physics in 5d compounds.
文摘This paper deals with the problem of distributed formation tracking control and obstacle avoidance of multivehicle systems(MVSs)in complex obstacle-laden environments.The MVS under consideration consists of a leader vehicle with an unknown control input and a group of follower vehicles,connected via a directed interaction topology,subject to simultaneous unknown heterogeneous nonlinearities and external disturbances.The central aim is to achieve effective and collisionfree formation tracking control for the nonlinear and uncertain MVS with obstacles encountered in formation maneuvering,while not demanding global information of the interaction topology.Toward this goal,a radial basis function neural network is used to model the unknown nonlinearity of vehicle dynamics in each vehicle and repulsive potentials are employed for obstacle avoidance.Furthermore,a scalable distributed adaptive formation tracking control protocol with a built-in obstacle avoidance mechanism is developed.It is proved that,with the proposed protocol,the resulting formation tracking errors are uniformly ultimately bounded and obstacle collision avoidance is guaranteed.Comprehensive simulation results are elaborated to substantiate the effectiveness and the promising collision avoidance performance of the proposed scalable adaptive formation control approach.
基金V. ACKNOWLEDGMENTS The computer simulation is performed on the High Performance Computing Center of Tianjin University,China. This work was supported by the National Natural Science Foundation of China （No.21274107 and No.91127046）. We thank Prof. Bin Zhang, Rui Xu, Bo Du, and Dr. Zi-lu Wang in Tianjin University for helpful discussions.
文摘Nanoparticles with competitive interactions in solution can aggregate into complex structures. In this work, the synergistic self-assembles of binary particles with electrostatic and van der Waals interactions are studied with the particle Langevin dynamics simulation using a simple coarse-grained particle model. Various aggregations such as spherical, stacking-disk and tube structures are observed by varying the particles size and the interaction strength. The aggregation structures are explained with the packing theories of amphiphilic molecules in solution and dibolck copolymers in bulk. When the opposite ions are introduced into solution, the distribution of structures in the phase diagram appears an obvious offset. The simulation result is helpful to deeply understand the formation mechanism of complex nanostructures of multicomponent particles in solution.
