Despite humanity's many lunar missions to the equatorial and mid-latitude regions,the south pole remains uncharted because of its exceptionally harsh conditions.The quest for water ice and the drive to establish l...Despite humanity's many lunar missions to the equatorial and mid-latitude regions,the south pole remains uncharted because of its exceptionally harsh conditions.The quest for water ice and the drive to establish lunar bases have positioned the south pole area above 80°latitude,characterized by permanently shaded regions and conducive to water ice preservation.However,the daunting terrain and intricate illumination in this area present significant challenges to engineering safety.Here,we introduce a Landing Feasibility Probability(LFP)model to evaluate the viability of potential landing sites.We pinpoint 120 prospective landing sites,stratified into 25 high-priority,64 medium-priority,and 31 lowpriority sites.These sites,encompassing a mere 0.6% of the lunar south pole,have been rigorously vetted against 10 critical factors for landing feasibility.These sites show a pronounced clustering around 8 major craters and plateaus,organizing into 7 lunar site networks,with each network comprising 4 sites with a maximum dimension under 25 km,ideal for the development of lunar bases and observational networks.The LFP model's selection process is derived from a heuristic Genetic Algorithm(GA)informed by expert experience.The landing sites are strategically positioned to address the dual challenges of scientific goals and engineering safety at the lunar south pole,while also providing site selection guidance and facilitating international collaboration and communication for lunar expeditions.This method can also be adapted for site selection on other celestial bodies(e.g.Mars and asteroids)for scientific exploration and construction of extraterrestrial bases.展开更多
This paper considers the unsteady boundary layer flow over a moving flat plate embedded in a porous medium with fractional Oldroyd-B viscoelastic fluid. The governing equations with mixed time-space fractional derivat...This paper considers the unsteady boundary layer flow over a moving flat plate embedded in a porous medium with fractional Oldroyd-B viscoelastic fluid. The governing equations with mixed time-space fractional derivatives are solved numerically by using the finite difference method combined with an L1-algorithm. The effect of various physical parameters on the velocity and average skin friction are discussed and graphically illustrated in detail. Results show that the porosity ε and fractional derivative a enhance the flow of Oldroyd-B viscoelastic fluid within porous medium, but fractional derivative weakens the flow. Moreover, it is found that the average skin friction coefficient rises with the increase of fractional derivative β.展开更多
Understanding the fundamental processes of charge carrier generation,separation,transport,and reactivity on the surface of semiconductors is crucial for the rational design of highperformance photo(electro)catalysts f...Understanding the fundamental processes of charge carrier generation,separation,transport,and reactivity on the surface of semiconductors is crucial for the rational design of highperformance photo(electro)catalysts for various energy conversion applications.Nevertheless,the ubiquitous and intricate heterogeneity exhibited by individual catalysts poses a significant obstacle to achieving a comprehensive understanding of the structure−function relationships using bulk-level,ensemble-averaged characterizations.This review highlights the emerging operando imaging techniques capable of providing local functional information,such as surface photovoltage,photoluminescence,charge carrier reaction rate,and photocurrent,at the single particle to subparticle level.By establishing correlations between the acquired local functional information and the specific structural characteristics of the catalyst,a quantitative,holistic understanding of the structure−function relationship in photo(electro)catalysts can be achieved.This understanding can serve as a foundation for guiding the design of photocatalysts with enhanced energy conversion performance.展开更多
基金supported by the National Natural Science Foundation of China(42371422 and 42221002).
文摘Despite humanity's many lunar missions to the equatorial and mid-latitude regions,the south pole remains uncharted because of its exceptionally harsh conditions.The quest for water ice and the drive to establish lunar bases have positioned the south pole area above 80°latitude,characterized by permanently shaded regions and conducive to water ice preservation.However,the daunting terrain and intricate illumination in this area present significant challenges to engineering safety.Here,we introduce a Landing Feasibility Probability(LFP)model to evaluate the viability of potential landing sites.We pinpoint 120 prospective landing sites,stratified into 25 high-priority,64 medium-priority,and 31 lowpriority sites.These sites,encompassing a mere 0.6% of the lunar south pole,have been rigorously vetted against 10 critical factors for landing feasibility.These sites show a pronounced clustering around 8 major craters and plateaus,organizing into 7 lunar site networks,with each network comprising 4 sites with a maximum dimension under 25 km,ideal for the development of lunar bases and observational networks.The LFP model's selection process is derived from a heuristic Genetic Algorithm(GA)informed by expert experience.The landing sites are strategically positioned to address the dual challenges of scientific goals and engineering safety at the lunar south pole,while also providing site selection guidance and facilitating international collaboration and communication for lunar expeditions.This method can also be adapted for site selection on other celestial bodies(e.g.Mars and asteroids)for scientific exploration and construction of extraterrestrial bases.
基金Supported by National Natural Science Foundation of China under Grant No.11101085
文摘This paper considers the unsteady boundary layer flow over a moving flat plate embedded in a porous medium with fractional Oldroyd-B viscoelastic fluid. The governing equations with mixed time-space fractional derivatives are solved numerically by using the finite difference method combined with an L1-algorithm. The effect of various physical parameters on the velocity and average skin friction are discussed and graphically illustrated in detail. Results show that the porosity ε and fractional derivative a enhance the flow of Oldroyd-B viscoelastic fluid within porous medium, but fractional derivative weakens the flow. Moreover, it is found that the average skin friction coefficient rises with the increase of fractional derivative β.
基金support from the National University of Singapore Presidential Young Professorship。
文摘Understanding the fundamental processes of charge carrier generation,separation,transport,and reactivity on the surface of semiconductors is crucial for the rational design of highperformance photo(electro)catalysts for various energy conversion applications.Nevertheless,the ubiquitous and intricate heterogeneity exhibited by individual catalysts poses a significant obstacle to achieving a comprehensive understanding of the structure−function relationships using bulk-level,ensemble-averaged characterizations.This review highlights the emerging operando imaging techniques capable of providing local functional information,such as surface photovoltage,photoluminescence,charge carrier reaction rate,and photocurrent,at the single particle to subparticle level.By establishing correlations between the acquired local functional information and the specific structural characteristics of the catalyst,a quantitative,holistic understanding of the structure−function relationship in photo(electro)catalysts can be achieved.This understanding can serve as a foundation for guiding the design of photocatalysts with enhanced energy conversion performance.
