With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization tech...With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.展开更多
Very recently,two-dimensional quantum dots(2D QDs)have been pioneeringly investigated as lubricant additives,which exhibit superior friction-reducing and wear resistance.Compared with 2D nanoparticles,2D QDs possess s...Very recently,two-dimensional quantum dots(2D QDs)have been pioneeringly investigated as lubricant additives,which exhibit superior friction-reducing and wear resistance.Compared with 2D nanoparticles,2D QDs possess small size(~10 nm)and abundant active groups.These distinguished advantages enable them to quickly disperse into common lube mediums and maintain long-term storage stability.The good dispersion stability of 2D QDs not only effectively improves their embedding capacity,but also enables continuous supplements of lubricants during the sliding process.Therefore,2D QDs are attracting increasing research interest as efficient lubricants with desirable service life.In this review,we focus on the latest studies of 2D QDs as liquid lubricant additives(both in polar and nonpolar mediums),self-lubricating solid coatings and gels,etc.Various advanced strategies for synthesis and modification of 2D QDs are summarized.A comprehensive insight into the tribological behavior of a variety of 2D QDs together with the associated mechanism is reviewed in detail.The superior lubricating performances of 2D QDs are attributed to various mechanisms,including rolling effect,self-mending performance,polishing effect,tribofilm formation,nanostructure transfer and synergistic effects,etc.Strategies for friction modulation of 2D QDs,including internal factors(surface modification,elemental doping)and extrinsic factors(counter surfaces,test conditions)are discussed,special attentions for achieving intelligent tribology toward superlubricity and bio-engineering,are also included.Finally,the future challenges and research directions regarding QDs as lubricants conforming to the concept of“green tribology”toward a sustainable society are discussed.展开更多
文摘With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.
基金This work was supported by the National Natural Science Foundation of China(No.52075264).
文摘Very recently,two-dimensional quantum dots(2D QDs)have been pioneeringly investigated as lubricant additives,which exhibit superior friction-reducing and wear resistance.Compared with 2D nanoparticles,2D QDs possess small size(~10 nm)and abundant active groups.These distinguished advantages enable them to quickly disperse into common lube mediums and maintain long-term storage stability.The good dispersion stability of 2D QDs not only effectively improves their embedding capacity,but also enables continuous supplements of lubricants during the sliding process.Therefore,2D QDs are attracting increasing research interest as efficient lubricants with desirable service life.In this review,we focus on the latest studies of 2D QDs as liquid lubricant additives(both in polar and nonpolar mediums),self-lubricating solid coatings and gels,etc.Various advanced strategies for synthesis and modification of 2D QDs are summarized.A comprehensive insight into the tribological behavior of a variety of 2D QDs together with the associated mechanism is reviewed in detail.The superior lubricating performances of 2D QDs are attributed to various mechanisms,including rolling effect,self-mending performance,polishing effect,tribofilm formation,nanostructure transfer and synergistic effects,etc.Strategies for friction modulation of 2D QDs,including internal factors(surface modification,elemental doping)and extrinsic factors(counter surfaces,test conditions)are discussed,special attentions for achieving intelligent tribology toward superlubricity and bio-engineering,are also included.Finally,the future challenges and research directions regarding QDs as lubricants conforming to the concept of“green tribology”toward a sustainable society are discussed.
