In the past a few years,there has been significant progress in theoretical characterizations of gas-surface reaction dynamics at the atomic level.One of the major breakthroughs is the machine learning representations ...In the past a few years,there has been significant progress in theoretical characterizations of gas-surface reaction dynamics at the atomic level.One of the major breakthroughs is the machine learning representations of the potential energy surfaces and related properties for molecules on metal surfaces from first-principles,particularly neural networks based methods.In this review,we focus on recent advances of the development and applications of high-dimensional symmetry-preserving neural network representations in gas-surface systems,which have enabled efficient Born-Oppenheimer molecular dynamics simulations with inclusion of all molecular and surface degrees of freedom,as well as some nonadiabatic molecular dynamics simulations with effective treatment of hot electrons,at the density function theory level.Despite these advances,further challenges remain.More accurate electronic structure theories and more efficient machine learning(and active learning)algorithms are needed towards a more quantitative description of more complex gas-surface reactions involving multiple surfaces and adsorbates or multiple electronic states.展开更多
The combined effect from sulfate and chloride is one of the important reasons to cause the damage of lining concrete in highway tunnels. To investigate the effect of chloride ions on the corrosion of lining concretes ...The combined effect from sulfate and chloride is one of the important reasons to cause the damage of lining concrete in highway tunnels. To investigate the effect of chloride ions on the corrosion of lining concretes under sulfate attack, ultrasonic detecting, compression test and X-ray Diffraction （XRD） were performed on the concretes to obtain the ultrasonic velocity, corrosion thickness, compression strength and corrosion products. The ultrasonic results, compression strength and XRD patterns confirmed that the existence of chloride certainly depressed the corrosion damage on the lining concretes under sulfate attack, and the depressing effect increased with the content of chloride in the composite solution. The corrosion damage on the concretes experienced three stages independent of the composition of corrosive solution： initial slower enhancement on the strength, stabilization period and linear degradation period. The existence of chloride mainly affected the final degradation stage and obviously decreased the corrosion thickness.展开更多
基金supported by the National Key R&D Program of China(2017YFA0303500)the National Natural Science Foundation of China(22073089 and 22033007)+1 种基金Anhui Initiative in Quantum Information Technologies(AHY090200)The Fundamen-tal Research Funds for the Central Universities(WK2060000017)。
文摘In the past a few years,there has been significant progress in theoretical characterizations of gas-surface reaction dynamics at the atomic level.One of the major breakthroughs is the machine learning representations of the potential energy surfaces and related properties for molecules on metal surfaces from first-principles,particularly neural networks based methods.In this review,we focus on recent advances of the development and applications of high-dimensional symmetry-preserving neural network representations in gas-surface systems,which have enabled efficient Born-Oppenheimer molecular dynamics simulations with inclusion of all molecular and surface degrees of freedom,as well as some nonadiabatic molecular dynamics simulations with effective treatment of hot electrons,at the density function theory level.Despite these advances,further challenges remain.More accurate electronic structure theories and more efficient machine learning(and active learning)algorithms are needed towards a more quantitative description of more complex gas-surface reactions involving multiple surfaces and adsorbates or multiple electronic states.
文摘The combined effect from sulfate and chloride is one of the important reasons to cause the damage of lining concrete in highway tunnels. To investigate the effect of chloride ions on the corrosion of lining concretes under sulfate attack, ultrasonic detecting, compression test and X-ray Diffraction （XRD） were performed on the concretes to obtain the ultrasonic velocity, corrosion thickness, compression strength and corrosion products. The ultrasonic results, compression strength and XRD patterns confirmed that the existence of chloride certainly depressed the corrosion damage on the lining concretes under sulfate attack, and the depressing effect increased with the content of chloride in the composite solution. The corrosion damage on the concretes experienced three stages independent of the composition of corrosive solution： initial slower enhancement on the strength, stabilization period and linear degradation period. The existence of chloride mainly affected the final degradation stage and obviously decreased the corrosion thickness.
