The formation,evolution,and dynamics of flow structures in wall-bounded turbulence have long been central themes in fluid-mechanics research.Over the past three decades,Soliton-like Coherent Structures(SCSs)have emerg...The formation,evolution,and dynamics of flow structures in wall-bounded turbulence have long been central themes in fluid-mechanics research.Over the past three decades,Soliton-like Coherent Structures(SCSs)have emerged as a ubiquitous and unifying feature across a wide range of shear flows,including K-type,O-type,N-type,and bypass transitional boundary layers,as well as fully developed turbulent boundary layers,mixing layers,and pipe flows.This paper presents a systematic review of the fundamental properties of SCSs and highlights their fundamental role in multiple transition scenarios.The analysis further explores the connection between SCSs and low-speed streaks,offering insight into their coupled dynamics.The phenomenon of turbulent bursting is also examined within the context of SCS dynamics.Together,these studies underscore the potential of SCSs to serve as a coherent dynamical framework for understanding turbulence generation mechanisms in wall-bounded flows.Finally,the review extends to the manifestation of SCSs in other canonical flows,including mixing layers,stratified shear flows,and jets,confirming their universality and significance in fluid dynamics.These findings not only advance our understanding of turbulence generation but also offer a promising theoretical foundation for future research in transitional and turbulent flows.展开更多
Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rat...Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems.展开更多
金川铜镍硫化物矿床是在采的世界第三大岩浆型铜镍硫化物矿床,其独特性在于微量元素特征暗示高程度的地壳混染作用,而硫同位素特征表明,硫的来源为地幔。利用前人总结的SCSS（sulfur content at sulfide saturation,即岩浆硫饱和时的硫...金川铜镍硫化物矿床是在采的世界第三大岩浆型铜镍硫化物矿床,其独特性在于微量元素特征暗示高程度的地壳混染作用,而硫同位素特征表明,硫的来源为地幔。利用前人总结的SCSS（sulfur content at sulfide saturation,即岩浆硫饱和时的硫含量）方程、推断的原生岩浆组分进行SCSS模拟计算,结合矿床超基性岩体微量元素特征,认识到：成矿母岩浆是地幔部分熔融的高镁拉斑玄武岩浆,部分熔融程度小于25%,形成时已接近硫饱和状态,在其上升进入深部岩浆房的过程中经历了约15%~35%的地壳物质同化混染,从而达到硫饱和状态。岩浆在岩浆房分异过程中,不断有同源近（已）硫化物饱和的岩浆补充进入岩浆房。展开更多
基金supported by the National Key Project(GJXM92579).
文摘The formation,evolution,and dynamics of flow structures in wall-bounded turbulence have long been central themes in fluid-mechanics research.Over the past three decades,Soliton-like Coherent Structures(SCSs)have emerged as a ubiquitous and unifying feature across a wide range of shear flows,including K-type,O-type,N-type,and bypass transitional boundary layers,as well as fully developed turbulent boundary layers,mixing layers,and pipe flows.This paper presents a systematic review of the fundamental properties of SCSs and highlights their fundamental role in multiple transition scenarios.The analysis further explores the connection between SCSs and low-speed streaks,offering insight into their coupled dynamics.The phenomenon of turbulent bursting is also examined within the context of SCS dynamics.Together,these studies underscore the potential of SCSs to serve as a coherent dynamical framework for understanding turbulence generation mechanisms in wall-bounded flows.Finally,the review extends to the manifestation of SCSs in other canonical flows,including mixing layers,stratified shear flows,and jets,confirming their universality and significance in fluid dynamics.These findings not only advance our understanding of turbulence generation but also offer a promising theoretical foundation for future research in transitional and turbulent flows.
基金supported by the National Natural Science Foundation of China(No.52175269)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)+2 种基金Science and Technology Research Project of Education Department of Jilin Province(JJKH20231146KJ,JJKH20241262KJ)Project ZR2024ME104 supported by Shandong Provincial Natural Science FoundationChina Postdoctoral Science Foundation(No.2024M751086).
文摘Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems.
文摘金川铜镍硫化物矿床是在采的世界第三大岩浆型铜镍硫化物矿床,其独特性在于微量元素特征暗示高程度的地壳混染作用,而硫同位素特征表明,硫的来源为地幔。利用前人总结的SCSS（sulfur content at sulfide saturation,即岩浆硫饱和时的硫含量）方程、推断的原生岩浆组分进行SCSS模拟计算,结合矿床超基性岩体微量元素特征,认识到：成矿母岩浆是地幔部分熔融的高镁拉斑玄武岩浆,部分熔融程度小于25%,形成时已接近硫饱和状态,在其上升进入深部岩浆房的过程中经历了约15%~35%的地壳物质同化混染,从而达到硫饱和状态。岩浆在岩浆房分异过程中,不断有同源近（已）硫化物饱和的岩浆补充进入岩浆房。
