Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the poten...Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the potential rangeρ=14 and the number of atoms N up to 400.All the putative global minima reported in the literature have been successfully reproduced with relatively high success ratios.Compared to the available results for N≤240 and several larger Morse clusters,new global minima(and local minima)with lower energies have been found out for N=164,175,188,193,194,197,239,246,260,318,and 389.Clusters with magic numbers are figured out through fitting the size-dependent global minimum energies.The cluster structures tend to be close-packed for short-range potential with large N.展开更多
Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atom...Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atomic multiphoton ionization. It is found that the photoelectron spectra are obviously different for the long-range （Coulomb-like） and short-range （with no excited bound states） potential model atoms, which are produced by two-colour coherent control of atomic multiphoton ionization in a few laser cycles. Our results indicate that two-colour coherent control of atomic multiphoton ionization can be observed in simulations, depending on the choice of the model potentials.展开更多
We present multi-threading and SIMD optimizations on short-range potential calculation kernel in Molecular Dynamics.For the multi-threading optimization,we design a partition-and-two-steps(PTS)method to avoid write co...We present multi-threading and SIMD optimizations on short-range potential calculation kernel in Molecular Dynamics.For the multi-threading optimization,we design a partition-and-two-steps(PTS)method to avoid write conflicts caused by using Newton’s third law.Our method eliminates serialization bottle-neck without extra memory.We implement our PTS method using OpenMP.Afterwards,we discuss the influence of the cutoff if statement on the performance of vectorization in MD simulations.We propose a pre-searching neighbors method,which makes about 70%atoms meet the cutoff check,reducing a large amount of redundant calculation.The experiment results prove our PTS method is scalable and efficient.In double precision,our 256-bit SIMD implementation is about 3×faster than the scalar version.展开更多
Chemical short-range order(SRO),a phenomenon at the atomic scale resulting from inhomogeneities in the local chemical environment,is usually studied using machine learning force field-based molecular dynamics simulati...Chemical short-range order(SRO),a phenomenon at the atomic scale resulting from inhomogeneities in the local chemical environment,is usually studied using machine learning force field-based molecular dynamics simulations due to the limitations of experimental methods.To promote the reliable application of machine potentials in high-entropy alloy simulations,first,this work uses NEP models trained on two different datasets to predict the SRO coefficients of NbMoTaW.The results show that within the same machine learning framework,there are significant differences in the prediction of SRO coefficients for the Nb-Nb atomic pair.Subsequently,this work predicts the SRO coefficients of NbMoTaW using the NEP model and the SNAP model,both of which are trained on the same dataset.The results reveal significant discrepancies in SRO predictions for like-element pairs(e.g.,Nb-Nb and W-W)between the two potentials,despite the identical training data.The findings of this study indicate that discrepancies in the prediction results of SRO coefficients can arise from either the same machine learning framework trained on different datasets or different learning frameworks trained on the same dataset.This reflects possible incompleteness in the current training set's coverage of local chemical environments at the atomic scale.Future research should establish unified evaluation standards to assess the capability of training sets to accurately describe complex atomic-scale behaviors such as SRO.展开更多
In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edg...In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edge of the grounding grid, was observed and analyzed under artificially triggered lightning conditions. Based on circuit theory and measured current data, a π-equivalent circuit was established to simulate the transient response of the grounding grid.Nineteen return strokes from three artificially triggered lightning events were analyzed. The peak currents of the 19 return strokes range from -6.7 to -25.1 kA, and the mean value was -14.3 kA. The GPR decreased rapidly and formed a subpeak after reaching the initial peak, with the mean value of the initial peak being -148.65 kV and the mean value of the subpeak being -92.87 kV. The GPR induced by the triggered lightning currents exhibited a subpeak phenomenon. Simulation results indicate that the subpeak phenomenon is related to localized corrosion of the vertical grounding electrode. The potential difference at the grounding grid edge exhibited a multi-pulse waveform with alternating polarity, dominated by positive pulses. The peak values of both the positive and negative polarity pulses gradually decreased, with the first positive pulse displaying a significantly higher intensity than that of subsequent pulses.展开更多
Molecular dynamics simulations were carried out to study the effect of chemical short-range order(CSRO)on the primary radiation damage in TiVTaNb high-entropy alloys(HEAs).We have performed displacement cascade simula...Molecular dynamics simulations were carried out to study the effect of chemical short-range order(CSRO)on the primary radiation damage in TiVTaNb high-entropy alloys(HEAs).We have performed displacement cascade simulations to explore the CSRO effect on the generation and evolution behaviors of irradiation defects.The results demonstrate that CSRO can suppress the formation of Frenkel pairs in TiVTaNb HEAs,with the suppression effect becoming more pronounced as the degree of CSRO increases.CSRO can change the types of interstitial defects generated during cascade collisions.Specifically,as the degree of CSRO increases,the proportion of Ti-related interstitials shows a marked enhancement,primarily evidenced by a significant rise in Ti–Ti dumbbells accompanied by a corresponding decrease in Ti–V dumbbells.CSRO exhibits negligible influence on defect clustering and the nucleation and evolution of dislocation loops.Regardless of CSRO conditions,TiVTaNb HEAs preserve exceptional radiation tolerance throughout the cascade damage process,suggesting that the intrinsic properties of this multi-principal element system dominate its radiation response.These findings provide fundamental insights into the CSRO effect on defect formation and evolution behaviors in HEAs,which may provide new design strategies for high-entropy alloys.展开更多
BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) a...BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.展开更多
Lead(Pb)is a typical low-melting-point ductile metal and serves as an important model material in the study of dynamic responses.Under shock-wave loading,its dynamic mechanical behavior comprises two key phenomena:pla...Lead(Pb)is a typical low-melting-point ductile metal and serves as an important model material in the study of dynamic responses.Under shock-wave loading,its dynamic mechanical behavior comprises two key phenomena:plastic deformation and shock-induced phase transitions.The underlying mechanisms of these processes are still poorly understood.Revealing these mechanisms remains challenging for experimental approaches.Non-equilibrium molecular dynamics(NEMD)simulations are an alternative theoretical tool for studying dynamic responses,as they capture atomic-scale mechanisms such as defect evolution and deformation pathways.However,due to the limited accuracy of empirical interatomic potentials,the reliability of previous NEMD studies has been questioned.Using our newly developed machine learning potential for Pb-Sn alloys,we revisited the microstructural evolution in response to shock loading under various shock orientations.The results reveal that shock loading along the[001]orientation of Pb exhibits a fast,reversible,and massive phase transition and stacking-fault evolution.The behavior of Pb differs from previous studies by the absence of twinning during plastic deformation.Loading along the[011]orientation leads to slow,irreversible plastic deformation,and a localized FCC-BCC phase transition in the Pitsch orientation relationship.This study provides crucial theoretical insights into the dynamic mechanical response of Pb,offering a theoretical input for understanding the microstructure-performance relationship under extreme conditions.展开更多
Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-con...Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-conjugated polymers.CMPs offer extensive versatility in synthetic approaches,enabling the synthesis of cross-linked and mesoporous structures.Advances in chemical processes,structural design,and synthesis methodologies have been developed,resulting in a diverse range of CMPs with unique configurations and properties,contributing to the fast expansion of the field.CMPs are particularly notable for their ability to enable the competitive utilization ofπ-conjugated structures within mesoporous configurations,making them valuable for investigations across various domains.They have shown considerable promise in addressing fuel and environmental challenges,demonstrated by their exceptional performance in applications such as vapor adsorption,heterogeneous catalysis,light emission,light harvesting,and energy generation.This review examines the chemical engineering principles underlying CMPs,including synthesis approaches,systemic research advancements,multifunctional investigations boundaries,potential applications,and progress in synthesis,dimensionality,and morphology studies.Specifically,it offers a comparative analysis of CMPs and linear polymeric materials,aiding in the development of functional polymers.Furthermore,this review explores the primary fundamental limitations of CMPs in fuel-related domains and discusses alternative strategies,including novel synthesis methods incorporating interactions and morphologies,to address these challenges.Ultimately,this assessment aims to provide a valuable and inspiring resource for professionals in the field of fuel management,guiding future research and development efforts.展开更多
Understanding the complex deformation mechanisms of non-equimolar multi-principal element alloys(MPEAs)requires high-fidelity atomic-scale simulations.This study develops a deep potential(DP)model to enable molecular ...Understanding the complex deformation mechanisms of non-equimolar multi-principal element alloys(MPEAs)requires high-fidelity atomic-scale simulations.This study develops a deep potential(DP)model to enable molecular dynamics simulations of the Ta_(0.4)Ti_(2)Zr(Ta_(0.4))alloy.Monte Carlo simulations using this potential reveal Ta atom precipitation in the Ta_(0.4)alloy.Under uniaxial tensile loading along the[100]direction in the NPT ensemble,the alloy undergoes a remarkable sequence of phase transformations:an initial body-centered cubic(BCC_(1))to face-centered cubic(FCC)transformation,followed by a reverse transformation from FCC to a distinct BCC phase(BCC_(2)),and finally a BCC_(2) to hexagonal close-packed(HCP)transformation.Critically,the reverse FCC to BCC_(2) transformation induces significant volume contraction.We demonstrate that the inversely transformed BCC_(2) phase primarily accommodates compressive stress.Concurrently,the reorientation of BCC_(2) crystals contributes substantially to the observed high strain hardening.These simulations provide atomic-scale insights into the dynamic structural evolution,sequential phase transformations,and stress partitioning during deformation of the Ta_(0.4)alloy.The developed DP model and the revealed mechanisms offer fundamental theoretical guidance for accelerating the design of high-performance MPEAs.展开更多
This study presents a multi-physical modeling approach to analyze the dynamics of moisture potential and stress-deformation features near deep desiccation cracks in clayey soils under three consecutive years’climate ...This study presents a multi-physical modeling approach to analyze the dynamics of moisture potential and stress-deformation features near deep desiccation cracks in clayey soils under three consecutive years’climate variability in an arid region.A triple research approach of statistical analysis,analytical framework,and numerical modeling was used to investigate the complex thermo-hydro-mechanical behavior of desiccation-cracked soil,incorporating realistic climatic data of Qom,Iran.The results revealed the interplay between stress,strain,and pore water pressure over time,demonstrating that soil experiences significant swelling and shrinkage due to cyclic wetting and drying.The horizontal stress distribution shows compressive stress concentration at crack tips during wetting,transitioning to tensile stresses uniformly across the soil surface during drying paths.Similarly,vertical stress distributions exhibit localized compressive stresses along crack boundaries during wetting and tensile stresses during drying,highlighting the critical stress conditions at crack tips.The model differentiates between microstructural and macrostructural changes in porosity.Annual trends in micro-porosity revealed cyclic-dependent behavior,with significant volumetric changes occurring in the first year,stabilizing with successive cycles.The results also indicated that part of the volumetric changes are irreversible,with volumetric plastic strain increasing exponentially but at a decreasing rate over three years.Principal stress analysis indicates a shift from compressive to tensile stress states around cracks,driven by climate-induced wetting and drying cycles.These findings underscore the critical role of climate variability in shaping cracked soil behavior in arid regions,providing insights into the heterogeneous behavior of cracked soil surfFicial layers.展开更多
Explosive cyclones(ECs) are rapidly intensifying subtropical cyclones that can develop within a short time and pose considerable threats to coastal areas in middle and high latitudes.Gaining a comprehensive understand...Explosive cyclones(ECs) are rapidly intensifying subtropical cyclones that can develop within a short time and pose considerable threats to coastal areas in middle and high latitudes.Gaining a comprehensive understanding of their formation,evolution,and mechanisms of explosive development is essential for improving forecasts of extreme weather events and mitigating associated impacts.Potential vorticity(PV),which is closely related to cyclone dynamics,serves as a valuable diagnostic tool in the study of ECs.In this study,two wintertime ECs of differing intensity over the Northwestern Pacific Ocean are analyzed to examine how different atmospheric processes influence PV generation and the rapid development of ECs.The maximum deepening rates of the two ECs are 2.81 Bergeron(called EC1) and 1.52 Bergeron(referred to as EC2).Results indicate that different stages of EC evolution are closely associated with PV tendency changes at different atmospheric levels.Using the PV tendency equation,during the explosive development of EC1,latent heat release may trigger the downward propagation of upper-level PV.For EC2,latent heat release notably enhances low-level PV,directly contributing to its rapid intensification.To validate these findings,sensitivity tests are conducted using the Weather Research and Forecasting model,with latent heat release turned off in the microphysical scheme for both cases.The results confirm the crucial role of latent heat release in generating low-level PV,further revealing that latent heat release contributes more to the explosive development of EC2 than that of EC1.展开更多
Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,w...Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,which significantly affects the transport of He within liquid Li—a vital aspect when considering liquid Li as a plasma-facing material in nuclear fusion reactors.We develop a machine-learning-based deep potential(DP)with ab initio accuracy for the Li-He system and perform molecular dynamics simulations at temperatures ranging from 470 K to 1270 K with a wide range of He concentrations.We observe that He atoms exhibit a tendency to aggregate and form clusters and bubbles in liquid Li.Notably,He clusters exhibit a significant increase in size at elevated temperatures and high concentrations of He,accompanied by the phase separation of Li and He atoms.We also observe an anomalous non-linear relationship between the diffusion coefficient of He and temperature,which is attributed to the larger cluster size at higher temperatures.Our study provides a deeper understanding of the behavior of He in liquid Li and further supports the potential application of liquid Li under extreme conditions.展开更多
The paper considers the initial value problem of inhomogeneous fourth-order Schr¨odinger equation with potential in energy space H^(2)(R^(d)).The global well-posedness is obtained in dimensions d≥5 resorting to ...The paper considers the initial value problem of inhomogeneous fourth-order Schr¨odinger equation with potential in energy space H^(2)(R^(d)).The global well-posedness is obtained in dimensions d≥5 resorting to contractive mapping principle,Strichartz estimates,Caffarelli-Kohn-Nirenberg-type inequality and the continuity method.展开更多
Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China ...Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China in winter and spring of 2021.The results show that the average concentration of PM_(2.5) decreased by 47%from winter to spring,while volume-normalized and mass-normalized OP(i.e.,OP_(v) and OP_(m))increased by 6%and 69%,respectively.It suggests that the decline of PM_(2.5) may not necessarily decrease the health risks and the intrinsic toxicity of PM_(2.5).Variations of OP_(v) and OP_(m) among different periods were related to the different source contributions and environmental conditions.The positive matrix factorization model was used to identify the major sources of OP_(v).OP_(v) was mainly contributed by biomass burning/industrial emissions(29%),soil/road dust(20%),secondary sulfate(14%),and coal combustion(13%)in winter.Different major sources were resolved to be secondary sulfate(36%),biological sources(21%),and marine vessels(20%)in spring,presenting the substantial contribution of biological sources.The analysis shows strong associations between OP_(v) and both live and dead bacteria,further confirming the important contribution of bioaerosols to the enhancement of OP.This study highlights the importance of understanding OP in ambient PM_(2.5) in terms of public health impact and provides a new insight into the biological contribution to OP.展开更多
Addiction,a complex and chronic neurobiological disorder,is characterized by compulsive substance use despite harmful consequences,leading to persistent alterations in brain function,particularly within the reward,mot...Addiction,a complex and chronic neurobiological disorder,is characterized by compulsive substance use despite harmful consequences,leading to persistent alterations in brain function,particularly within the reward,motivation,and decision-making systems.Despite the availability of a range of treatment options,including pharmacotherapy and behavioral therapies,relapse remains a major challenge,with many individuals struggling to maintain long-term recovery.Current treatments often show limited efficacy,underscoring the need for novel therapeutic strategies that can address the underlying neurobiological disruptions in addiction.展开更多
All-solid-state batteries(ASSBs)represent a next-generation energy storage technology,offering enhanced safety,higher energy density,and improved cycling stability compared to conventional liquid-electrolyte-based lit...All-solid-state batteries(ASSBs)represent a next-generation energy storage technology,offering enhanced safety,higher energy density,and improved cycling stability compared to conventional liquid-electrolyte-based lithium-ion batteries.Understanding and optimizing the complex chemistries and interfaces that underpin ASSB performance present significant challenges from both experimental and modeling perspectives.In particular,atomistic simulations face difficulties in capturing the complex structure,disorder,and dynamic evolution of materials and interfaces under practically relevant conditions.While established methods such as density functional theory and classical force fields have provided valuable insights,some questions remain difficult to address,particularly those involving large system sizes or long timescales.Recently,machine learning interatomic potentials(MLIPs)have emerged as a transformative tool,enabling atomistic simulations at length and time scales that were previously challenging to access with conventional approaches.By delivering near first-principles accuracy with much greater efficiency,MLIPs open new avenues for large-scale,long-timescale,and high-throughput simulations of solid-state battery materials.In this review,we present a comparative overview of density functional theory,classical force fields,and MLIPs,highlighting their respective strengths and limitations in ASSB research.We then discuss how MLIPs enable simulations that reach longer timescales,larger system sizes,and support high-throughput calculations,providing unique insights into ion transport and interfacial evolution in ASSBs.Finally,we conclude with a summary and outlook on current challenges and future opportunities for expanding MLIP capabilities and accelerating their impact in solid-state battery research.展开更多
The high-order deformation effects in even-even^(246,248)No are investigated by means of pairing self-consistent WoodsSaxon-Strutinsky calculations using the potential-energy-surface(PES)approach in an extended deform...The high-order deformation effects in even-even^(246,248)No are investigated by means of pairing self-consistent WoodsSaxon-Strutinsky calculations using the potential-energy-surface(PES)approach in an extended deformation space(β_(2),β_(3),β_(4),β_(5),β_(6),β_(7),β_(8)).Based on the calculated two-dimensional projected energy maps and different potential energy curves,we found that the highly even-order deformations have an important impact on both the fission trajectory and energy minima,while the odd-order deformations,accompanying the even-order ones,primarily affect the fission path beyond the second barrier.Relative to the light actinide nuclei,the nuclear ground state changes to the superdeformed configuration,but the normally deformed minimum,as the low-energy shape isomer,may still be primarily responsible for enhancing nuclear stability and ensuring experimental accessibility in^(246,248)No.Our present investigation indicates the nonnegligible impact of high-order deformation effects along the fission valley and will be helpful for deepening the understanding of different deformation effects and deformation couplings in nuclei,especially in this neutron-deficient heavy-mass region.展开更多
Land use conflicts(LUCs)pose a major challenge to urbanization,and their effective regulation is essential for promoting sustainable regional land use.However,the influence of urban development on conflicts has often ...Land use conflicts(LUCs)pose a major challenge to urbanization,and their effective regulation is essential for promoting sustainable regional land use.However,the influence of urban development on conflicts has often been overlooked.This study developed an index system from three dimensions—agricultural production,residential life,and ecological security—and quantified LUCs in China using spatial statistics and a coupling relationship matrix.It further explored the spatial relationships between conflict types and urban built-up areas(UBA)through accessibility analysis,and applied regression analysis to reveal the spatial evolution of conflicts from an urban-scale perspective.The results showed that agricultural-construction conflicts were concentrated in the eastern plains,while agricultural-ecological conflicts prevailed in the mountainous areas in the western region.Spatial distribution of the distance from conflicts to UBA(DCU)exhibited a clear east-west gradient,being closer in the east(less than 20 km)and farther in the west.Between 2000 and 2020,LUCs moved progressively closer to UBA,except in the ecologically fragile western region.For all urban hierarchies except small cities,the average distance was below 10 km;megacities exhibited the shortest DCU,roughly half that of small cities.Moreover,LUCs displayed significant hierarchical scale effects:as urban size increased,distance tended to decrease in a non-linear pattern,with the steepest decline occurring in central China.Land management authorities should work to curb sprawling urban development.Overall,this study provides new insights into the spatial evolution of LUCs and contributes to more sustainable land use management.展开更多
Adult neurogenesis is generally considered to be very limited;however,there is increasing evidence that this phenomenon is conserved across species.Traditionally,research has focused on identifying precursor cells,tho...Adult neurogenesis is generally considered to be very limited;however,there is increasing evidence that this phenomenon is conserved across species.Traditionally,research has focused on identifying precursor cells,those that are actively dividing or have the potential to divide.Direct evidence of adult neurogenesis has been found in rats,mice,songbirds,and nonhuman primates.In humans,while the evidence is indirect,it strongly suggests that neurogenesis also occurs during adulthood.In mammals,this active neurogenesis is preserved by radial glial progenitors,which remain in specific niches in the subventricular zone of the lateral ventricles and in the subgranular zone of the hippocampal dentate gyrus(Kumar et al.,2019).展开更多
基金supported by the National Natural Science Foundation of China(No.21803053)the Natural Science Foundation of Zhejiang Province,China(No.LY20B030005)the Open Project Fund of Key Laboratory of Excited-State Materials of Zhejiang Province。
文摘Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the potential rangeρ=14 and the number of atoms N up to 400.All the putative global minima reported in the literature have been successfully reproduced with relatively high success ratios.Compared to the available results for N≤240 and several larger Morse clusters,new global minima(and local minima)with lower energies have been found out for N=164,175,188,193,194,197,239,246,260,318,and 389.Clusters with magic numbers are figured out through fitting the size-dependent global minimum energies.The cluster structures tend to be close-packed for short-range potential with large N.
基金Project supported by the National Natural Science Foundation of China （Grant No 10674112） and the Young Teachers Foundation of Northwest Normal University （Grant No NWNU-QN-04-25）.
文摘Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atomic multiphoton ionization. It is found that the photoelectron spectra are obviously different for the long-range （Coulomb-like） and short-range （with no excited bound states） potential model atoms, which are produced by two-colour coherent control of atomic multiphoton ionization in a few laser cycles. Our results indicate that two-colour coherent control of atomic multiphoton ionization can be observed in simulations, depending on the choice of the model potentials.
文摘We present multi-threading and SIMD optimizations on short-range potential calculation kernel in Molecular Dynamics.For the multi-threading optimization,we design a partition-and-two-steps(PTS)method to avoid write conflicts caused by using Newton’s third law.Our method eliminates serialization bottle-neck without extra memory.We implement our PTS method using OpenMP.Afterwards,we discuss the influence of the cutoff if statement on the performance of vectorization in MD simulations.We propose a pre-searching neighbors method,which makes about 70%atoms meet the cutoff check,reducing a large amount of redundant calculation.The experiment results prove our PTS method is scalable and efficient.In double precision,our 256-bit SIMD implementation is about 3×faster than the scalar version.
基金Project supported by the Hunan Provincial Natural Science Foundation(Grant Nos.2024JJ6190 and 2024JK2007-1)。
文摘Chemical short-range order(SRO),a phenomenon at the atomic scale resulting from inhomogeneities in the local chemical environment,is usually studied using machine learning force field-based molecular dynamics simulations due to the limitations of experimental methods.To promote the reliable application of machine potentials in high-entropy alloy simulations,first,this work uses NEP models trained on two different datasets to predict the SRO coefficients of NbMoTaW.The results show that within the same machine learning framework,there are significant differences in the prediction of SRO coefficients for the Nb-Nb atomic pair.Subsequently,this work predicts the SRO coefficients of NbMoTaW using the NEP model and the SNAP model,both of which are trained on the same dataset.The results reveal significant discrepancies in SRO predictions for like-element pairs(e.g.,Nb-Nb and W-W)between the two potentials,despite the identical training data.The findings of this study indicate that discrepancies in the prediction results of SRO coefficients can arise from either the same machine learning framework trained on different datasets or different learning frameworks trained on the same dataset.This reflects possible incompleteness in the current training set's coverage of local chemical environments at the atomic scale.Future research should establish unified evaluation standards to assess the capability of training sets to accurately describe complex atomic-scale behaviors such as SRO.
基金National Natural Science Foundation of China(42575091)Marine Meteorological Science and Data Center Program (2024B1212070014)。
文摘In this study, the ground potential rise(GPR) phenomenon caused by a lightning current injected into a field-shaped artificial grounding grid, as well as the potential difference between two different nodes at the edge of the grounding grid, was observed and analyzed under artificially triggered lightning conditions. Based on circuit theory and measured current data, a π-equivalent circuit was established to simulate the transient response of the grounding grid.Nineteen return strokes from three artificially triggered lightning events were analyzed. The peak currents of the 19 return strokes range from -6.7 to -25.1 kA, and the mean value was -14.3 kA. The GPR decreased rapidly and formed a subpeak after reaching the initial peak, with the mean value of the initial peak being -148.65 kV and the mean value of the subpeak being -92.87 kV. The GPR induced by the triggered lightning currents exhibited a subpeak phenomenon. Simulation results indicate that the subpeak phenomenon is related to localized corrosion of the vertical grounding electrode. The potential difference at the grounding grid edge exhibited a multi-pulse waveform with alternating polarity, dominated by positive pulses. The peak values of both the positive and negative polarity pulses gradually decreased, with the first positive pulse displaying a significantly higher intensity than that of subsequent pulses.
基金Project supported by the Youth Program of the National Natural Science Foundation of China(Grant No.12405324)the CNNC Science Fund for Talented Young Scholars(Grant No.24940)the CNNC Basic Science Fund(Grant No.24851)。
文摘Molecular dynamics simulations were carried out to study the effect of chemical short-range order(CSRO)on the primary radiation damage in TiVTaNb high-entropy alloys(HEAs).We have performed displacement cascade simulations to explore the CSRO effect on the generation and evolution behaviors of irradiation defects.The results demonstrate that CSRO can suppress the formation of Frenkel pairs in TiVTaNb HEAs,with the suppression effect becoming more pronounced as the degree of CSRO increases.CSRO can change the types of interstitial defects generated during cascade collisions.Specifically,as the degree of CSRO increases,the proportion of Ti-related interstitials shows a marked enhancement,primarily evidenced by a significant rise in Ti–Ti dumbbells accompanied by a corresponding decrease in Ti–V dumbbells.CSRO exhibits negligible influence on defect clustering and the nucleation and evolution of dislocation loops.Regardless of CSRO conditions,TiVTaNb HEAs preserve exceptional radiation tolerance throughout the cascade damage process,suggesting that the intrinsic properties of this multi-principal element system dominate its radiation response.These findings provide fundamental insights into the CSRO effect on defect formation and evolution behaviors in HEAs,which may provide new design strategies for high-entropy alloys.
基金supported by the CAMS Innovation Fund for Medical Sciences (CIFMS)(No.2021-1-I2M-020)National High Level Hospital Clinical Research Funding (No.2022-PUMCH-B-109)National Natural Science Foundation of China (82402543)。
文摘BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1004300)the National Natural Science Foundation of China(Grant No.12404004)。
文摘Lead(Pb)is a typical low-melting-point ductile metal and serves as an important model material in the study of dynamic responses.Under shock-wave loading,its dynamic mechanical behavior comprises two key phenomena:plastic deformation and shock-induced phase transitions.The underlying mechanisms of these processes are still poorly understood.Revealing these mechanisms remains challenging for experimental approaches.Non-equilibrium molecular dynamics(NEMD)simulations are an alternative theoretical tool for studying dynamic responses,as they capture atomic-scale mechanisms such as defect evolution and deformation pathways.However,due to the limited accuracy of empirical interatomic potentials,the reliability of previous NEMD studies has been questioned.Using our newly developed machine learning potential for Pb-Sn alloys,we revisited the microstructural evolution in response to shock loading under various shock orientations.The results reveal that shock loading along the[001]orientation of Pb exhibits a fast,reversible,and massive phase transition and stacking-fault evolution.The behavior of Pb differs from previous studies by the absence of twinning during plastic deformation.Loading along the[011]orientation leads to slow,irreversible plastic deformation,and a localized FCC-BCC phase transition in the Pitsch orientation relationship.This study provides crucial theoretical insights into the dynamic mechanical response of Pb,offering a theoretical input for understanding the microstructure-performance relationship under extreme conditions.
基金supported by the King Khalid University,Abha,Saudi Arabiathe Deanship of Scientific Research at King Khalid University for funding this work through Large Groups Project under grant number(R.G.P.2/335/46)the Guangdong Office of Research Projects at the Provincial University(No.2024KCXTD064)。
文摘Conjugated microporous polymers(CMPs)are a unique class of organic porous materials characterized byπ-conjugated structures and permanent micropores,distinguishing them from non-porous polymers and conventionalπ-conjugated polymers.CMPs offer extensive versatility in synthetic approaches,enabling the synthesis of cross-linked and mesoporous structures.Advances in chemical processes,structural design,and synthesis methodologies have been developed,resulting in a diverse range of CMPs with unique configurations and properties,contributing to the fast expansion of the field.CMPs are particularly notable for their ability to enable the competitive utilization ofπ-conjugated structures within mesoporous configurations,making them valuable for investigations across various domains.They have shown considerable promise in addressing fuel and environmental challenges,demonstrated by their exceptional performance in applications such as vapor adsorption,heterogeneous catalysis,light emission,light harvesting,and energy generation.This review examines the chemical engineering principles underlying CMPs,including synthesis approaches,systemic research advancements,multifunctional investigations boundaries,potential applications,and progress in synthesis,dimensionality,and morphology studies.Specifically,it offers a comparative analysis of CMPs and linear polymeric materials,aiding in the development of functional polymers.Furthermore,this review explores the primary fundamental limitations of CMPs in fuel-related domains and discusses alternative strategies,including novel synthesis methods incorporating interactions and morphologies,to address these challenges.Ultimately,this assessment aims to provide a valuable and inspiring resource for professionals in the field of fuel management,guiding future research and development efforts.
基金supported by the National University of Defense Technology Research Fund Projectthe National Natural Science Foundation of China(Grant No.12534013)the Science and Technology Innovation Program of Hunan Province(Grant Nos.2025ZYJ001 and 2021RC4026)。
文摘Understanding the complex deformation mechanisms of non-equimolar multi-principal element alloys(MPEAs)requires high-fidelity atomic-scale simulations.This study develops a deep potential(DP)model to enable molecular dynamics simulations of the Ta_(0.4)Ti_(2)Zr(Ta_(0.4))alloy.Monte Carlo simulations using this potential reveal Ta atom precipitation in the Ta_(0.4)alloy.Under uniaxial tensile loading along the[100]direction in the NPT ensemble,the alloy undergoes a remarkable sequence of phase transformations:an initial body-centered cubic(BCC_(1))to face-centered cubic(FCC)transformation,followed by a reverse transformation from FCC to a distinct BCC phase(BCC_(2)),and finally a BCC_(2) to hexagonal close-packed(HCP)transformation.Critically,the reverse FCC to BCC_(2) transformation induces significant volume contraction.We demonstrate that the inversely transformed BCC_(2) phase primarily accommodates compressive stress.Concurrently,the reorientation of BCC_(2) crystals contributes substantially to the observed high strain hardening.These simulations provide atomic-scale insights into the dynamic structural evolution,sequential phase transformations,and stress partitioning during deformation of the Ta_(0.4)alloy.The developed DP model and the revealed mechanisms offer fundamental theoretical guidance for accelerating the design of high-performance MPEAs.
基金support provided by the Research Grant Office at Sharif University Technology by way of grants G4010902 and QB020105 is gratefully acknowledged.
文摘This study presents a multi-physical modeling approach to analyze the dynamics of moisture potential and stress-deformation features near deep desiccation cracks in clayey soils under three consecutive years’climate variability in an arid region.A triple research approach of statistical analysis,analytical framework,and numerical modeling was used to investigate the complex thermo-hydro-mechanical behavior of desiccation-cracked soil,incorporating realistic climatic data of Qom,Iran.The results revealed the interplay between stress,strain,and pore water pressure over time,demonstrating that soil experiences significant swelling and shrinkage due to cyclic wetting and drying.The horizontal stress distribution shows compressive stress concentration at crack tips during wetting,transitioning to tensile stresses uniformly across the soil surface during drying paths.Similarly,vertical stress distributions exhibit localized compressive stresses along crack boundaries during wetting and tensile stresses during drying,highlighting the critical stress conditions at crack tips.The model differentiates between microstructural and macrostructural changes in porosity.Annual trends in micro-porosity revealed cyclic-dependent behavior,with significant volumetric changes occurring in the first year,stabilizing with successive cycles.The results also indicated that part of the volumetric changes are irreversible,with volumetric plastic strain increasing exponentially but at a decreasing rate over three years.Principal stress analysis indicates a shift from compressive to tensile stress states around cracks,driven by climate-induced wetting and drying cycles.These findings underscore the critical role of climate variability in shaping cracked soil behavior in arid regions,providing insights into the heterogeneous behavior of cracked soil surfFicial layers.
基金financially supported by the National Key R&D Program of China (No. 2022YFC3004204)the National Natural Science Foundation of China (No. 42275001)the Natural Science Foundation of Shandong Province (No. ZR2022MD038)。
文摘Explosive cyclones(ECs) are rapidly intensifying subtropical cyclones that can develop within a short time and pose considerable threats to coastal areas in middle and high latitudes.Gaining a comprehensive understanding of their formation,evolution,and mechanisms of explosive development is essential for improving forecasts of extreme weather events and mitigating associated impacts.Potential vorticity(PV),which is closely related to cyclone dynamics,serves as a valuable diagnostic tool in the study of ECs.In this study,two wintertime ECs of differing intensity over the Northwestern Pacific Ocean are analyzed to examine how different atmospheric processes influence PV generation and the rapid development of ECs.The maximum deepening rates of the two ECs are 2.81 Bergeron(called EC1) and 1.52 Bergeron(referred to as EC2).Results indicate that different stages of EC evolution are closely associated with PV tendency changes at different atmospheric levels.Using the PV tendency equation,during the explosive development of EC1,latent heat release may trigger the downward propagation of upper-level PV.For EC2,latent heat release notably enhances low-level PV,directly contributing to its rapid intensification.To validate these findings,sensitivity tests are conducted using the Weather Research and Forecasting model,with latent heat release turned off in the microphysical scheme for both cases.The results confirm the crucial role of latent heat release in generating low-level PV,further revealing that latent heat release contributes more to the explosive development of EC2 than that of EC1.
基金Project supported by the Excellence Research Group Program for Multiscale Problems in Nonlinear Mechanics of the National Natural Science Foundation of China(Grant No.12588201)the National Key R&D Program of China(Grant No.2025YFB3003603)+1 种基金the National Natural Science Foundation of China(Grant No.12135002)the Fundamental Research Funds for the Central Universities,Peking University,the Beijing Natural Science Foundation(Grant No.QY23030)。
文摘Current experimental techniques still face challenges in clarifying the structural and dynamic properties of helium(He)in liquid lithium(Li).A critical example of this technical hurdle is the formation of He bubbles,which significantly affects the transport of He within liquid Li—a vital aspect when considering liquid Li as a plasma-facing material in nuclear fusion reactors.We develop a machine-learning-based deep potential(DP)with ab initio accuracy for the Li-He system and perform molecular dynamics simulations at temperatures ranging from 470 K to 1270 K with a wide range of He concentrations.We observe that He atoms exhibit a tendency to aggregate and form clusters and bubbles in liquid Li.Notably,He clusters exhibit a significant increase in size at elevated temperatures and high concentrations of He,accompanied by the phase separation of Li and He atoms.We also observe an anomalous non-linear relationship between the diffusion coefficient of He and temperature,which is attributed to the larger cluster size at higher temperatures.Our study provides a deeper understanding of the behavior of He in liquid Li and further supports the potential application of liquid Li under extreme conditions.
基金Supported by National Natural Science Foundation of China(Grant No.11601122).
文摘The paper considers the initial value problem of inhomogeneous fourth-order Schr¨odinger equation with potential in energy space H^(2)(R^(d)).The global well-posedness is obtained in dimensions d≥5 resorting to contractive mapping principle,Strichartz estimates,Caffarelli-Kohn-Nirenberg-type inequality and the continuity method.
基金supported by the National Natural Science Foundation of China(No.41975156)and the Fundamental Research Funds for the Central Universities.
文摘Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China in winter and spring of 2021.The results show that the average concentration of PM_(2.5) decreased by 47%from winter to spring,while volume-normalized and mass-normalized OP(i.e.,OP_(v) and OP_(m))increased by 6%and 69%,respectively.It suggests that the decline of PM_(2.5) may not necessarily decrease the health risks and the intrinsic toxicity of PM_(2.5).Variations of OP_(v) and OP_(m) among different periods were related to the different source contributions and environmental conditions.The positive matrix factorization model was used to identify the major sources of OP_(v).OP_(v) was mainly contributed by biomass burning/industrial emissions(29%),soil/road dust(20%),secondary sulfate(14%),and coal combustion(13%)in winter.Different major sources were resolved to be secondary sulfate(36%),biological sources(21%),and marine vessels(20%)in spring,presenting the substantial contribution of biological sources.The analysis shows strong associations between OP_(v) and both live and dead bacteria,further confirming the important contribution of bioaerosols to the enhancement of OP.This study highlights the importance of understanding OP in ambient PM_(2.5) in terms of public health impact and provides a new insight into the biological contribution to OP.
基金supported by the National Natural Science Foundation of China(T2350008)the STI2030-Major Projects[2021ZD0203000(2021ZD0203003)]the Open Research Fund of the State Key Laboratory of Brain-Machine Intelligence,Zhejiang University(BMI2400014).
文摘Addiction,a complex and chronic neurobiological disorder,is characterized by compulsive substance use despite harmful consequences,leading to persistent alterations in brain function,particularly within the reward,motivation,and decision-making systems.Despite the availability of a range of treatment options,including pharmacotherapy and behavioral therapies,relapse remains a major challenge,with many individuals struggling to maintain long-term recovery.Current treatments often show limited efficacy,underscoring the need for novel therapeutic strategies that can address the underlying neurobiological disruptions in addiction.
文摘All-solid-state batteries(ASSBs)represent a next-generation energy storage technology,offering enhanced safety,higher energy density,and improved cycling stability compared to conventional liquid-electrolyte-based lithium-ion batteries.Understanding and optimizing the complex chemistries and interfaces that underpin ASSB performance present significant challenges from both experimental and modeling perspectives.In particular,atomistic simulations face difficulties in capturing the complex structure,disorder,and dynamic evolution of materials and interfaces under practically relevant conditions.While established methods such as density functional theory and classical force fields have provided valuable insights,some questions remain difficult to address,particularly those involving large system sizes or long timescales.Recently,machine learning interatomic potentials(MLIPs)have emerged as a transformative tool,enabling atomistic simulations at length and time scales that were previously challenging to access with conventional approaches.By delivering near first-principles accuracy with much greater efficiency,MLIPs open new avenues for large-scale,long-timescale,and high-throughput simulations of solid-state battery materials.In this review,we present a comparative overview of density functional theory,classical force fields,and MLIPs,highlighting their respective strengths and limitations in ASSB research.We then discuss how MLIPs enable simulations that reach longer timescales,larger system sizes,and support high-throughput calculations,providing unique insights into ion transport and interfacial evolution in ASSBs.Finally,we conclude with a summary and outlook on current challenges and future opportunities for expanding MLIP capabilities and accelerating their impact in solid-state battery research.
基金supported by the Natural Science Foundation of Henan Province(No.252300421478)the National Natural Science Foundation of China(Nos.11975209,U2032211,12075287)。
文摘The high-order deformation effects in even-even^(246,248)No are investigated by means of pairing self-consistent WoodsSaxon-Strutinsky calculations using the potential-energy-surface(PES)approach in an extended deformation space(β_(2),β_(3),β_(4),β_(5),β_(6),β_(7),β_(8)).Based on the calculated two-dimensional projected energy maps and different potential energy curves,we found that the highly even-order deformations have an important impact on both the fission trajectory and energy minima,while the odd-order deformations,accompanying the even-order ones,primarily affect the fission path beyond the second barrier.Relative to the light actinide nuclei,the nuclear ground state changes to the superdeformed configuration,but the normally deformed minimum,as the low-energy shape isomer,may still be primarily responsible for enhancing nuclear stability and ensuring experimental accessibility in^(246,248)No.Our present investigation indicates the nonnegligible impact of high-order deformation effects along the fission valley and will be helpful for deepening the understanding of different deformation effects and deformation couplings in nuclei,especially in this neutron-deficient heavy-mass region.
基金National Natural Science Foundation of China,No.72474216。
文摘Land use conflicts(LUCs)pose a major challenge to urbanization,and their effective regulation is essential for promoting sustainable regional land use.However,the influence of urban development on conflicts has often been overlooked.This study developed an index system from three dimensions—agricultural production,residential life,and ecological security—and quantified LUCs in China using spatial statistics and a coupling relationship matrix.It further explored the spatial relationships between conflict types and urban built-up areas(UBA)through accessibility analysis,and applied regression analysis to reveal the spatial evolution of conflicts from an urban-scale perspective.The results showed that agricultural-construction conflicts were concentrated in the eastern plains,while agricultural-ecological conflicts prevailed in the mountainous areas in the western region.Spatial distribution of the distance from conflicts to UBA(DCU)exhibited a clear east-west gradient,being closer in the east(less than 20 km)and farther in the west.Between 2000 and 2020,LUCs moved progressively closer to UBA,except in the ecologically fragile western region.For all urban hierarchies except small cities,the average distance was below 10 km;megacities exhibited the shortest DCU,roughly half that of small cities.Moreover,LUCs displayed significant hierarchical scale effects:as urban size increased,distance tended to decrease in a non-linear pattern,with the steepest decline occurring in central China.Land management authorities should work to curb sprawling urban development.Overall,this study provides new insights into the spatial evolution of LUCs and contributes to more sustainable land use management.
文摘Adult neurogenesis is generally considered to be very limited;however,there is increasing evidence that this phenomenon is conserved across species.Traditionally,research has focused on identifying precursor cells,those that are actively dividing or have the potential to divide.Direct evidence of adult neurogenesis has been found in rats,mice,songbirds,and nonhuman primates.In humans,while the evidence is indirect,it strongly suggests that neurogenesis also occurs during adulthood.In mammals,this active neurogenesis is preserved by radial glial progenitors,which remain in specific niches in the subventricular zone of the lateral ventricles and in the subgranular zone of the hippocampal dentate gyrus(Kumar et al.,2019).
