The suppression of ablative Rayleigh–Taylor instability(ARTI)by a spatially modulated laser in inertial confinement fusion(ICF)is studied through numerical simulations.The results show that in the acceleration phase ...The suppression of ablative Rayleigh–Taylor instability(ARTI)by a spatially modulated laser in inertial confinement fusion(ICF)is studied through numerical simulations.The results show that in the acceleration phase of ICF implosion,the growth of ARTI can be suppressed by using a short-wavelength spatially modulated laser.The ARTI growth rate decreases as the wavelength of the spatially modulated laser decreases,and ARTI is completely suppressed after a certain wavelength has been reached.A spatially uniform laser is introduced to keep the state of motion of the implosion fluid consistent,and it is found that the proportion of the spatially modulated laser required for complete suppression of ARTI decreases as the wavelength continues to decrease.We also optimize the spatial intensity distribution of the spatially modulated laser.In addition,as the duration of the spatially modulated laser decreases,the proportion required for completely suppressing ARTI increases,but the required energy decreases.When the perturbation wavenumber decreases,the wavelength of the spatially modulated laser required for complete suppression of ARTI becomes longer.In the case of multimode perturbation,ARTI can also be significantly suppressed by a spatially modulated laser,and the perturbation amplitude can be reduced to less than 10% of that without a spatially modulated laser.We believe that the conclusions drawn from our simulations can provide the basis for new approaches to control ARTI in ICF.展开更多
Large-angle stimulated Raman scattering(LA-SRS)in a longitudinally inhomogeneous plasma with a transverse density modulation is studied using a three-wave coupled model and numerical simulations.The simulations show t...Large-angle stimulated Raman scattering(LA-SRS)in a longitudinally inhomogeneous plasma with a transverse density modulation is studied using a three-wave coupled model and numerical simulations.The simulations show that the scattering angle of SRS in a longitudinally inhomogeneous plasma can be significantly affected by transverse density modulation.Under transverse density modulation conditions,the laser focuses into underdense regions,owing to the transversely modulated refractive index.The angle of LA-SRS,neither a purely 90° angle side scattering nor purely backscattering,is almost consistent with the specific angle at which the density inhomogeneity vanishes.In modulated plasmas,the nonuniform distribution of laser intensity shifts the regions of scattering and gain compared with those in uniform plasmas,ultimately affecting the laser transmission.SRS is suppressed in weakly modulated regimes,whereas it is enhanced under strong modulation conditions,and a theoretical criterion distinguishing between strong and weak modulation is established.展开更多
In recent years,the environmental and health impacts ofnanoplastics have garnered significant attention,often portrayed as a novel and distinct threat.1−3 However,a groundbreaking study by Yan et al.challenges this na...In recent years,the environmental and health impacts ofnanoplastics have garnered significant attention,often portrayed as a novel and distinct threat.1−3 However,a groundbreaking study by Yan et al.challenges this narrative,arguing that the toxicity of nanoplastics is fundamentally a subset of the well-established field of nanotoxicology.4 Through extensive data mining,machine learning,and molecular dynamics simulations,the authors demonstrate that nanoplastics and engineered nanoparticles(ENPs)share striking similarities in their physicochemical properties,environmental behaviors,biological interactions,and toxicity profiles.This revelation calls for a paradigm shift in how nanoplastics research is conducted,advocating for the integration of this field into the broader nanotoxicology framework to avoid redundant efforts and accelerate the development of sustainable solutions.展开更多
A coarse-grained neuroevolution potential(CGNEP)for multilayered graphene based on an ab initio accuracy dataset is developed for mesoscalemolecular dynamics simulations.The information loss in coarsening process is d...A coarse-grained neuroevolution potential(CGNEP)for multilayered graphene based on an ab initio accuracy dataset is developed for mesoscalemolecular dynamics simulations.The information loss in coarsening process is discussed and divided into intralayer part and interlayer part.The CGNEP describes the interlayer shear introduced by van der Waals interactions well by modifying the descriptor of NEP.The mechanical properties and vibration frequencies of structures of different sizes are well predicted via CGNEP.Compared with the traditional empirical CG potential,the CGNEP possesses interlayer properties of the structure of graphene and maintains the ability for higher mapping ratio coarsening.The frequencies of a 12-layer graphene membrane with a length and width of 1μm are directly calculated via the CGNEP with a 64:1 mapping ratio and compared with the experimental results.The proposed CGNEP may be further used for other multilayered CG 2D materials.展开更多
We present a robust protocol for affordable learning of electronic states to accelerate photophysical and photochemical molecular simulations.The protocol solves several issues precluding the widespread use of machine...We present a robust protocol for affordable learning of electronic states to accelerate photophysical and photochemical molecular simulations.The protocol solves several issues precluding the widespread use of machine learning(ML)in excited-state simulations.We introduce a novel physicsinformed multi-state ML model that can learn an arbitrary number of excited states across molecules,with accuracy better or similar to the accuracy of learning ground-state energies,where information on excited-state energies improves the quality of ground-state predictions.We also present gap-driven dynamics for accelerated sampling of the small-gap regions,which proves crucial for stable surfacehopping dynamics.Together,multi-state learning and gap-driven dynamics enable efficient active learning,furnishing robust models for surface-hopping simulations and helping to uncover long-timescale oscillations in cis-azobenzene photoisomerization.Our active-learning protocol includes sampling based on physics-informed uncertainty quantification,ensuring the quality of each adiabatic surface,low error in energy gaps,and precise calculation of the hopping probability.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.12074399,12204500,and 12004403)the Key Projects of Intergovernmental International Scientific and Technological Innovation Cooperation(No.2021YFE0116700)+1 种基金the Shanghai Natural Science Foundation(No.20ZR1464400)the Shanghai Sailing Program(No.22YF1455300).
文摘The suppression of ablative Rayleigh–Taylor instability(ARTI)by a spatially modulated laser in inertial confinement fusion(ICF)is studied through numerical simulations.The results show that in the acceleration phase of ICF implosion,the growth of ARTI can be suppressed by using a short-wavelength spatially modulated laser.The ARTI growth rate decreases as the wavelength of the spatially modulated laser decreases,and ARTI is completely suppressed after a certain wavelength has been reached.A spatially uniform laser is introduced to keep the state of motion of the implosion fluid consistent,and it is found that the proportion of the spatially modulated laser required for complete suppression of ARTI decreases as the wavelength continues to decrease.We also optimize the spatial intensity distribution of the spatially modulated laser.In addition,as the duration of the spatially modulated laser decreases,the proportion required for completely suppressing ARTI increases,but the required energy decreases.When the perturbation wavenumber decreases,the wavelength of the spatially modulated laser required for complete suppression of ARTI becomes longer.In the case of multimode perturbation,ARTI can also be significantly suppressed by a spatially modulated laser,and the perturbation amplitude can be reduced to less than 10% of that without a spatially modulated laser.We believe that the conclusions drawn from our simulations can provide the basis for new approaches to control ARTI in ICF.
基金supported by the National Natural Science Foundation of China under Grant Nos.U2430207,12035002,and 12305258by the CAEP Foundation under Grant No.YZJJZQ2023020.
文摘Large-angle stimulated Raman scattering(LA-SRS)in a longitudinally inhomogeneous plasma with a transverse density modulation is studied using a three-wave coupled model and numerical simulations.The simulations show that the scattering angle of SRS in a longitudinally inhomogeneous plasma can be significantly affected by transverse density modulation.Under transverse density modulation conditions,the laser focuses into underdense regions,owing to the transversely modulated refractive index.The angle of LA-SRS,neither a purely 90° angle side scattering nor purely backscattering,is almost consistent with the specific angle at which the density inhomogeneity vanishes.In modulated plasmas,the nonuniform distribution of laser intensity shifts the regions of scattering and gain compared with those in uniform plasmas,ultimately affecting the laser transmission.SRS is suppressed in weakly modulated regimes,whereas it is enhanced under strong modulation conditions,and a theoretical criterion distinguishing between strong and weak modulation is established.
基金supported by the National Natural Science Foundation of China(Grants 22241604 and 22125606).
文摘In recent years,the environmental and health impacts ofnanoplastics have garnered significant attention,often portrayed as a novel and distinct threat.1−3 However,a groundbreaking study by Yan et al.challenges this narrative,arguing that the toxicity of nanoplastics is fundamentally a subset of the well-established field of nanotoxicology.4 Through extensive data mining,machine learning,and molecular dynamics simulations,the authors demonstrate that nanoplastics and engineered nanoparticles(ENPs)share striking similarities in their physicochemical properties,environmental behaviors,biological interactions,and toxicity profiles.This revelation calls for a paradigm shift in how nanoplastics research is conducted,advocating for the integration of this field into the broader nanotoxicology framework to avoid redundant efforts and accelerate the development of sustainable solutions.
基金supported in part by the National Natural Science Foundation of China under Grant Nos. U2341230 and 12472016.
文摘A coarse-grained neuroevolution potential(CGNEP)for multilayered graphene based on an ab initio accuracy dataset is developed for mesoscalemolecular dynamics simulations.The information loss in coarsening process is discussed and divided into intralayer part and interlayer part.The CGNEP describes the interlayer shear introduced by van der Waals interactions well by modifying the descriptor of NEP.The mechanical properties and vibration frequencies of structures of different sizes are well predicted via CGNEP.Compared with the traditional empirical CG potential,the CGNEP possesses interlayer properties of the structure of graphene and maintains the ability for higher mapping ratio coarsening.The frequencies of a 12-layer graphene membrane with a length and width of 1μm are directly calculated via the CGNEP with a 64:1 mapping ratio and compared with the experimental results.The proposed CGNEP may be further used for other multilayered CG 2D materials.
基金the Polish Ministry of Education and Science for funding this research under the program “Perły Nauki,” grant number PN/01/0064/2022, amount of funding, and the total value of the project: 239 800,00 PLNas well as gratefully acknowledge Polish high-performance computing infrastructure PLGrid (HPC Centers: ACK Cyfronet AGH) for providing computer facilities and support within computational grant no. PLG/2024/017363+3 种基金M.B. thanks the funding provided by the European Research Council (ERC) Advanced grant SubNano (Grant agreement 832237)M.B. received support from the French government under the France 2030 as part of the initiative d’Excellence d’Aix-Marseille Université, A*MIDEX (AMX-22-IN1-48)P.O.D. acknowledges funding from the National Natural Science Foundation of China (via the Outstanding Youth Scholars (Overseas, 2021) project)via the Lab project of the State Key Laboratory of Physical Chemistry of Solid Surfaces. The computations were performed using the XACS cloud computing resources. The authors also acknowledge Max Pinheiro Jr, Prateek Goel, and Bao-Xin Xue for many non-published tests of not-so-successful protocols.
文摘We present a robust protocol for affordable learning of electronic states to accelerate photophysical and photochemical molecular simulations.The protocol solves several issues precluding the widespread use of machine learning(ML)in excited-state simulations.We introduce a novel physicsinformed multi-state ML model that can learn an arbitrary number of excited states across molecules,with accuracy better or similar to the accuracy of learning ground-state energies,where information on excited-state energies improves the quality of ground-state predictions.We also present gap-driven dynamics for accelerated sampling of the small-gap regions,which proves crucial for stable surfacehopping dynamics.Together,multi-state learning and gap-driven dynamics enable efficient active learning,furnishing robust models for surface-hopping simulations and helping to uncover long-timescale oscillations in cis-azobenzene photoisomerization.Our active-learning protocol includes sampling based on physics-informed uncertainty quantification,ensuring the quality of each adiabatic surface,low error in energy gaps,and precise calculation of the hopping probability.
