Long-lasting constant loading commonly exists in silicon-based microelectronic contact,as well as the chemical mechanical polishing area.In this work,the stress relaxation analysis of single crystal silicon coated wit...Long-lasting constant loading commonly exists in silicon-based microelectronic contact,as well as the chemical mechanical polishing area.In this work,the stress relaxation analysis of single crystal silicon coated with an amorphous SiO_(2) film is performed by varying the maximum indentation depth using molecular dynamics simulation.It is found that during holding,the applied indentation force declines sharply at the beginning and then steadily towards the end of the holding period.The stress relaxation amount of bilayer composites increases as the maximum indentation depth increases.It is also found that the deformation features of SiO_(2) film and silicon substrate during holding are inherited from the loading process.The SiO_(2) film during holding is further densified when the maximum indentation depth is equal to or less than a certain value(5.5 nm for the 0.8-nm film).The amount of generated phases and phase distributions of silicon substrate during holding are affected by the plastic deformation of silicon during loading.展开更多
Adaptive Laboratory Evolution(ALE),a well-established framework in microbial evolution research,is widely applied in synthetic biology.By simulating natural selection through controlled serial culturing,ALE promotes t...Adaptive Laboratory Evolution(ALE),a well-established framework in microbial evolution research,is widely applied in synthetic biology.By simulating natural selection through controlled serial culturing,ALE promotes the accumulation of beneficial mutations,leading to the emergence of specific adaptive phenotypes and bypassing the complexities inherent in rational genetic engineering.With advancements in next-generation sequencing and molecular biology,the integration of high-throughput omics and molecular tools with ALE has significantly enhanced the mapping of genotype-phenotype relationships and the characterization of mutational landscapes.This has propelled progress in microbial evolution,biochemical theory,and interdisci-plinary applications.Escherichia coli(E.coli),a premier chassis in synthetic biology,benefits from its genetic tractability and metabolic flexibility,making it an ideal model for ALE studies.This review examines recent developments in ALE applications for E.coli,exploring its methodological principles,experimental design par-adigms,notable case studies,and synergies with emerging technologies,providing valuable theoretical insights and practical guidance for related research.展开更多
The surface planarity and asperity removal behavior on atomic scale in an ultrathin water environment were studied for a nanoscale process by molecular dynamics simulation.Monolayer atomic removal is achieved under bo...The surface planarity and asperity removal behavior on atomic scale in an ultrathin water environment were studied for a nanoscale process by molecular dynamics simulation.Monolayer atomic removal is achieved under both noncontact and monoatomic layer contact conditions with different water film thicknesses.The newly formed surface is relatively smooth without deformed layers,and no plastic defects are present in the subsurface.The nanoscale processing is governed by the interatomic adhering action during which the water film transmits the loading forces to the Cu surface and thereby results in the migration and removal of the surface atoms.When the scratching depth≥0.5 nm,the abrasive particle squeezes out the water film from the scratching region and scratches the Cu surface directly.This leads to the formation of trenches and ridges,accumulation of chips ahead of the particles,and generation of dislocations within the Cu substrate.This process is mainly governed by the plowing action,leading to the deterioration of the surface quality.This study makes the"0 nm planarity,0 residual defects,and 0 polishing pressure"in a nanoscale process more achievable and is helpful in understanding the nanoscale removal of materials for developing an ultra-precision manufacture technology.展开更多
基金The authors thank Zhi Chen for his help in radial distribution function.This study was supported by the National Natural Science Foundation of China(Grant Numbers 51375364,51475359,and 51505479)Natural Science Foundation of Jiangsu Province of China(BK20150184).
文摘Long-lasting constant loading commonly exists in silicon-based microelectronic contact,as well as the chemical mechanical polishing area.In this work,the stress relaxation analysis of single crystal silicon coated with an amorphous SiO_(2) film is performed by varying the maximum indentation depth using molecular dynamics simulation.It is found that during holding,the applied indentation force declines sharply at the beginning and then steadily towards the end of the holding period.The stress relaxation amount of bilayer composites increases as the maximum indentation depth increases.It is also found that the deformation features of SiO_(2) film and silicon substrate during holding are inherited from the loading process.The SiO_(2) film during holding is further densified when the maximum indentation depth is equal to or less than a certain value(5.5 nm for the 0.8-nm film).The amount of generated phases and phase distributions of silicon substrate during holding are affected by the plastic deformation of silicon during loading.
基金supported by the Youth Student Fundamental Research Funds of Shandong University(SDUQM2422)the National Key R&D Program of China(No.2024YFC3407100)+2 种基金the National Nat-ural Science Foundation of China(32470065)Hainan Province Science and Technology Special Fund(No.ZDYF2024XDNY164)SKLMT Frontiers and Challenges Project(SKLMTFCP-2023-03).
文摘Adaptive Laboratory Evolution(ALE),a well-established framework in microbial evolution research,is widely applied in synthetic biology.By simulating natural selection through controlled serial culturing,ALE promotes the accumulation of beneficial mutations,leading to the emergence of specific adaptive phenotypes and bypassing the complexities inherent in rational genetic engineering.With advancements in next-generation sequencing and molecular biology,the integration of high-throughput omics and molecular tools with ALE has significantly enhanced the mapping of genotype-phenotype relationships and the characterization of mutational landscapes.This has propelled progress in microbial evolution,biochemical theory,and interdisci-plinary applications.Escherichia coli(E.coli),a premier chassis in synthetic biology,benefits from its genetic tractability and metabolic flexibility,making it an ideal model for ALE studies.This review examines recent developments in ALE applications for E.coli,exploring its methodological principles,experimental design par-adigms,notable case studies,and synergies with emerging technologies,providing valuable theoretical insights and practical guidance for related research.
基金National Natural Science Foundation of China[Grant numbers 51375364 and 51475359]Natural Science Foundation of Shaanxi Province of China[2014JM6219]。
文摘The surface planarity and asperity removal behavior on atomic scale in an ultrathin water environment were studied for a nanoscale process by molecular dynamics simulation.Monolayer atomic removal is achieved under both noncontact and monoatomic layer contact conditions with different water film thicknesses.The newly formed surface is relatively smooth without deformed layers,and no plastic defects are present in the subsurface.The nanoscale processing is governed by the interatomic adhering action during which the water film transmits the loading forces to the Cu surface and thereby results in the migration and removal of the surface atoms.When the scratching depth≥0.5 nm,the abrasive particle squeezes out the water film from the scratching region and scratches the Cu surface directly.This leads to the formation of trenches and ridges,accumulation of chips ahead of the particles,and generation of dislocations within the Cu substrate.This process is mainly governed by the plowing action,leading to the deterioration of the surface quality.This study makes the"0 nm planarity,0 residual defects,and 0 polishing pressure"in a nanoscale process more achievable and is helpful in understanding the nanoscale removal of materials for developing an ultra-precision manufacture technology.
