Inspired by the diverse wrinkled surface patterns in nature,micro-nano scale wrinkled surfaces have become an essential part of materials science.Nowadays,it is still a challenge to flexibly fabricate three-dimensiona...Inspired by the diverse wrinkled surface patterns in nature,micro-nano scale wrinkled surfaces have become an essential part of materials science.Nowadays,it is still a challenge to flexibly fabricate three-dimensional(3D)nanowrinkled structures with precise configuration.Herein,we introduce a reaction-diffusion-based self-organized Turing mechanism integrated with femtosecond laser direct writing(FsLDW)to achieve controlled anisotropic photopolymerization,fabricating 3D hydrogel-based biomimetic Turing nanowrinkled structures.This approach enables precise spatial modulation of wrinkle periodicity,orientation,and amplitude.Furthermore,using methacrylated hyaluronic acid(MeHA)monomers,we elucidate the mechanistic interplay between anisotropic photopolymerization and Turing-patterned nanowrinkle formation.We further propose a theoretical framework—the polarization modulation of femtosecond laser pulses enables the anisotropic photopolymerization of Turing-patterned nanowrinkles,selectively generating aligned linear(Turing-line)and vertically ordered pillar(Turing-column)structures.According to this theoretical framework,we propose the concept of the nanowrinkle parameter(Wr),alongside an empirical formula derived from two-photon polymerization(TPP)fabrication parameters to predict Turing nanowrinkle emergence conditions.We also demonstrate the ability to create high-resolution,3D nanowrinkled structures,including patterned structures,bio-inspired microvilli resembling those of the small intestine,cicada wing replicas,and moth-eye structures.Moreover,we functionalize Turing-patterned structures with magnetron-sputtered Ag coatings,creating microano-devices for molecular surface enhanced Raman scattering(SERS)detection.The Turing-inspired SERS devices demonstrate ultra-trace detection capability for Rhodamine 6G(R6G)at concentrations as low as 10−9M.This work provides a novel,high-precision methodology for the fabrication of complex,bionic,free-form Turing nanowrinkled structures.展开更多
The Turing instability,a counterintuitive phenomenon in which two quiescent cells lose stability when coupled through a dissipative environment,has been explained via the edge of chaos theory.While the classical Turin...The Turing instability,a counterintuitive phenomenon in which two quiescent cells lose stability when coupled through a dissipative environment,has been explained via the edge of chaos theory.While the classical Turing instability and its local form have been recently elucidated,its symmetrical form—a distinct class of symmetry-breaking phenomena wherein two identical cells,each poised at a mirror-symmetrical stable operating point,undergo destabilization and bifurcate into two distinct mirror-symmetrical stable states under opposite bias voltages—has not been reported yet.This paper introduces a current-controlled odd-symmetrical Chua corsage memristor(OS-CCM)and employs it to investigate the symmetrical Turing instability in a resistively coupled two-cell network.Coupling two identical bistable OS-CCM-based cells,each originally poised at identical mirror-symmetrical stable states,via a passive resistor destabilizes their original stability,giving rise to two distinct stable states and ultimately leading to quadristability,referring to a dynamical phenomenon with four coexisting stable states,which demonstrates the emergence of symmetrical Turing instability.The quantitative condition for the emergence of this phenomenon is analytically derived and precisely determined through eigenvalue analysis.Both numerical simulations and hardware experiments confirm the correctness of the theoretical analysis.展开更多
Achieving industrial-level electrochemical CO2reduction to formate remains a significant challenge due to limitations in catalyst selectivity and interfacial proton management at high current densities.In a recent ...Achieving industrial-level electrochemical CO2reduction to formate remains a significant challenge due to limitations in catalyst selectivity and interfacial proton management at high current densities.In a recent study,Prof.Guo and colleagues report the development of Turingstructured electrocatalysts,which incorporate reaction-diffusion-inspired topologies to engineer mesoscale surface patterns.This design enables precise modulation of the interfacial microenvironment,enhancing CO2activation and suppressing competing hydrogen evolution.The resulting catalysts achieve efficient and stable CO2-to-formate conversion under industrially relevant conditions,offering a promising strategy for scalable carbon-neutral chemical production.展开更多
A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary ...A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary patterns to asynchronous and synchronous oscillatory patterns are obtained.A novel method based on decomposing coupled systems into two associated subsystems has been proposed to elucidate the mechanism of formation of oscillating patterns.Linear stability analysis of the associated subsystems reveals that the Turing pattern in one layer induces the other layer locally,undergoes a supercritical Hopf bifurcation and gives rise to localized oscillations.It is found that the sizes and positions of oscillations are determined by the spatial distribution of the Turing patterns.When the size is large,localized traveling waves such as spirals and targets emerge.These results may be useful for deeper understanding of pattern formation in complex systems,particularly multilayered systems.展开更多
HONG KONG,Dec.19(Xinhua)--The resources China funnels into college education,along with its vast talent pool,will help foster the development of artificial intelligence(AI),said 1986 Turing Award winner John Edward Ho...HONG KONG,Dec.19(Xinhua)--The resources China funnels into college education,along with its vast talent pool,will help foster the development of artificial intelligence(AI),said 1986 Turing Award winner John Edward Hopcroft on Friday on the sidelines of the inaugural Hong Kong AI Art Festival.展开更多
It is well-known that reaction–diffusion systems are used to describe the pattern formation models. In this paper,we will investigate the pattern formation generated by the fractional reaction–diffusion systems. We ...It is well-known that reaction–diffusion systems are used to describe the pattern formation models. In this paper,we will investigate the pattern formation generated by the fractional reaction–diffusion systems. We first explore the mathematical mechanism of the pattern by applying the linear stability analysis for the fractional Gierer–Meinhardt system.Then, an efficient high-precision numerical scheme is used in the numerical simulation. The proposed method is based on an exponential time differencing Runge–Kutta method in temporal direction and a Fourier spectral method in spatial direction. This method has the advantages of high precision, better stability, and less storage. Numerical simulations show that the system control parameters and fractional order exponent have decisive influence on the generation of patterns. Our numerical results verify our theoretical results.展开更多
基金supported by the National Key R&D Program of China(Grant No.2024YFB4607402)the National Natural Science Foundation of China(NSFC,Grant Nos.61975213,51901234,and 61475164)International Partnership Program of Chinese Academy of Sciences(GJHZ2021130).
摘要Inspired by the diverse wrinkled surface patterns in nature,micro-nano scale wrinkled surfaces have become an essential part of materials science.Nowadays,it is still a challenge to flexibly fabricate three-dimensional(3D)nanowrinkled structures with precise configuration.Herein,we introduce a reaction-diffusion-based self-organized Turing mechanism integrated with femtosecond laser direct writing(FsLDW)to achieve controlled anisotropic photopolymerization,fabricating 3D hydrogel-based biomimetic Turing nanowrinkled structures.This approach enables precise spatial modulation of wrinkle periodicity,orientation,and amplitude.Furthermore,using methacrylated hyaluronic acid(MeHA)monomers,we elucidate the mechanistic interplay between anisotropic photopolymerization and Turing-patterned nanowrinkle formation.We further propose a theoretical framework—the polarization modulation of femtosecond laser pulses enables the anisotropic photopolymerization of Turing-patterned nanowrinkles,selectively generating aligned linear(Turing-line)and vertically ordered pillar(Turing-column)structures.According to this theoretical framework,we propose the concept of the nanowrinkle parameter(Wr),alongside an empirical formula derived from two-photon polymerization(TPP)fabrication parameters to predict Turing nanowrinkle emergence conditions.We also demonstrate the ability to create high-resolution,3D nanowrinkled structures,including patterned structures,bio-inspired microvilli resembling those of the small intestine,cicada wing replicas,and moth-eye structures.Moreover,we functionalize Turing-patterned structures with magnetron-sputtered Ag coatings,creating microano-devices for molecular surface enhanced Raman scattering(SERS)detection.The Turing-inspired SERS devices demonstrate ultra-trace detection capability for Rhodamine 6G(R6G)at concentrations as low as 10−9M.This work provides a novel,high-precision methodology for the fabrication of complex,bionic,free-form Turing nanowrinkled structures.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.62501213 and 62574072)Zhejiang Provincial Natural Science Foundation of China(Grant No.LQN25F010008)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.GK249909299001-025)。
摘要The Turing instability,a counterintuitive phenomenon in which two quiescent cells lose stability when coupled through a dissipative environment,has been explained via the edge of chaos theory.While the classical Turing instability and its local form have been recently elucidated,its symmetrical form—a distinct class of symmetry-breaking phenomena wherein two identical cells,each poised at a mirror-symmetrical stable operating point,undergo destabilization and bifurcate into two distinct mirror-symmetrical stable states under opposite bias voltages—has not been reported yet.This paper introduces a current-controlled odd-symmetrical Chua corsage memristor(OS-CCM)and employs it to investigate the symmetrical Turing instability in a resistively coupled two-cell network.Coupling two identical bistable OS-CCM-based cells,each originally poised at identical mirror-symmetrical stable states,via a passive resistor destabilizes their original stability,giving rise to two distinct stable states and ultimately leading to quadristability,referring to a dynamical phenomenon with four coexisting stable states,which demonstrates the emergence of symmetrical Turing instability.The quantitative condition for the emergence of this phenomenon is analytically derived and precisely determined through eigenvalue analysis.Both numerical simulations and hardware experiments confirm the correctness of the theoretical analysis.
基金financially supported by the National Natural Science Foundation of China(No.22209024)Tongcheng R&D Foundation(No.CPCIF-RA-0102)the State Key Laboratory of Advanced Fiber Materials,Donghua University
摘要Achieving industrial-level electrochemical CO2reduction to formate remains a significant challenge due to limitations in catalyst selectivity and interfacial proton management at high current densities.In a recent study,Prof.Guo and colleagues report the development of Turingstructured electrocatalysts,which incorporate reaction-diffusion-inspired topologies to engineer mesoscale surface patterns.This design enables precise modulation of the interfacial microenvironment,enhancing CO2activation and suppressing competing hydrogen evolution.The resulting catalysts achieve efficient and stable CO2-to-formate conversion under industrially relevant conditions,offering a promising strategy for scalable carbon-neutral chemical production.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275065,12275064,12475203)the Natural Science Foundation of Hebei Province(Grant Nos.A2021201010 and A2024201020)+3 种基金Interdisciplinary Research Program of Natural Science of Hebei University(Grant No.DXK202108)Hebei Provincial Central Government Guiding Local Science and Technology Development Funds(Grant No.236Z1501G)Scientific Research and Innovation Team Foundation of Hebei University(Grant No.IT2023B03)the Excellent Youth Research Innovation Team of Hebei University(Grant No.QNTD202402)。
摘要A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary patterns to asynchronous and synchronous oscillatory patterns are obtained.A novel method based on decomposing coupled systems into two associated subsystems has been proposed to elucidate the mechanism of formation of oscillating patterns.Linear stability analysis of the associated subsystems reveals that the Turing pattern in one layer induces the other layer locally,undergoes a supercritical Hopf bifurcation and gives rise to localized oscillations.It is found that the sizes and positions of oscillations are determined by the spatial distribution of the Turing patterns.When the size is large,localized traveling waves such as spirals and targets emerge.These results may be useful for deeper understanding of pattern formation in complex systems,particularly multilayered systems.
摘要HONG KONG,Dec.19(Xinhua)--The resources China funnels into college education,along with its vast talent pool,will help foster the development of artificial intelligence(AI),said 1986 Turing Award winner John Edward Hopcroft on Friday on the sidelines of the inaugural Hong Kong AI Art Festival.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61573008 and 61703290)Natural Science Foundation of Liaoning Province,China(Grant No.20180550996)
摘要It is well-known that reaction–diffusion systems are used to describe the pattern formation models. In this paper,we will investigate the pattern formation generated by the fractional reaction–diffusion systems. We first explore the mathematical mechanism of the pattern by applying the linear stability analysis for the fractional Gierer–Meinhardt system.Then, an efficient high-precision numerical scheme is used in the numerical simulation. The proposed method is based on an exponential time differencing Runge–Kutta method in temporal direction and a Fourier spectral method in spatial direction. This method has the advantages of high precision, better stability, and less storage. Numerical simulations show that the system control parameters and fractional order exponent have decisive influence on the generation of patterns. Our numerical results verify our theoretical results.