Reaction-diffusion systems are widely used to describe pattern formation,and various control strategies have been applied to reaction-diffusion systems to achieve control objectives such as boundary control,output fee...Reaction-diffusion systems are widely used to describe pattern formation,and various control strategies have been applied to reaction-diffusion systems to achieve control objectives such as boundary control,output feedback stabilization,and synchronization.However,controlling pattern dynamics in reaction-diffusion systems with fractional-order diffusion remains an unresolved problem.This paper presents a proportional-derivative(PD)control strategy for the Schnakenberg system with fractional-order diffusion and cross-diffusion.Theoretical analysis explores the amplitude equation near the Turing bifurcation threshold,determining the selection and stability of pattern formations.Numerical simulations demonstrate that the PD controller accomplishes the modification of pattern structures and suppression of Turing instability by adjusting only two control parameters.Additionally,it is found that for smaller fractional diffusion order,the region can accommodate more hexagonal and stripe patterns in space.This work contributes to the control of complex pattern dynamics and offers a new approach to enhancing stability in fractional reaction-diffusion systems.展开更多
Tangent hyperbolic fluids characterized by shear-thinning behavior,are widely utilized in diverse industrial and scientific fields such as polymer engineering,inkjet printing,biofluids modeling,thermal insulation mate...Tangent hyperbolic fluids characterized by shear-thinning behavior,are widely utilized in diverse industrial and scientific fields such as polymer engineering,inkjet printing,biofluids modeling,thermal insulation materials,and chemical manufacturing.Additionally,double-diffusive convection involving simultaneous heat and mass transfer driven by temperature and concentration gradients plays a critical role in many natural and industrial systems,including oceanic circulation,geothermal energy extraction,crystal solidification,alloy formation,and enhanced oil recovery.The current work examines the peristaltic transport of a tangent hyperbolic nanofluid under the concurrent effects of thermal radiation,electroosmotic forces,slip boundary conditions,and double diffusion.The governing nonlinear equations are numerically solved using Mathematica’s NDSolve command after being simplified under the presumptions of a long wavelength,a low Reynolds number,and Debye-Huckel linearization.The analysis reveals that a rise in the velocity slip parameter decreases the core fluid velocity but increases it closer to channel walls,while increased solutal Grashof number and electroosmotic parameter result in non-uniform velocity distributions,reducing the flow towards the left wall and increasing it towards the right.The pressure gradient increases with higher electroosmotic effects and Helmholtz-Smoluchowski velocity,but decreases under more intense thermal radiation and increased Prandtl number.The magnetic field increases pressure in the retrograde area and moves the enhanced zone towards the right wall,emphasizing increased flow resistance.Also,the trapping effects intensify with increasing solutal Grashof number and Helmholtz-Smoluchowski velocity,providing better particle transport and mixing in microfluidic devices.展开更多
Emerging bio-inspired computing systems simulate the cognitive functions of the brain for the realiza-tion of future computing systems.For the development of such efficient neuromorphic electronics,the emulation of sh...Emerging bio-inspired computing systems simulate the cognitive functions of the brain for the realiza-tion of future computing systems.For the development of such efficient neuromorphic electronics,the emulation of short-term and long-term synaptic plasticity behaviors of the biological synapses is an es-sential step.However,the electronic synaptic devices suffer from higher variability issues which hinder the application of such devices to build neuromorphic systems.For practical applications,it is essen-tial to minimize the cycle-to-cycle and device-to-device variations in the synaptic functions of artifi-cial electronic synapses.This study involves the fabrication of diffusive memristor devices using WTe_(2) chalcogenide as the main switching material.The choice of the switching material provides a facile so-lution to the variability problem.The greater uniformity in the switching characteristics of the WTe_(2)-based memristor offers higher uniformity for the synaptic emulation.These devices exhibit both volatile and nonvolatile switching properties,allowing them to emulate both short-term and long-term synaptic functions.The WTe_(2)-based electronic synaptic devices present a high degree of uniformity for the emula-tion of various essential biological synaptic functions including short-term potentiation(STP),long-term potentiation(LTP),long-term depression(LTD),spike-rate-dependent plasticity(SRDP),and spike-timing-dependent plasticity(STDP).A higher recognition accuracy of∼92%is attained for pattern recognition using the modified National Institute of Standards and Technology(MNIST)handwritten digits,which is attributed to the enhanced linearity and higher uniformity of LTP/LTD characteristics.展开更多
An experimental study of the diffusive mass transfer between a droplet and an oscillating immiscible liquid in a horizontal axisymmetricHele-Shaw cell is carried out.Theliquid oscillates radially in the cell.Thetransv...An experimental study of the diffusive mass transfer between a droplet and an oscillating immiscible liquid in a horizontal axisymmetricHele-Shaw cell is carried out.Theliquid oscillates radially in the cell.Thetransverse size of the droplet exceeds the cell thickness.The viscosities of the droplet and the surrounding liquid are comparable.Relevant effort is provided to design and test an experimental setup and validate a protocol for determining the mass transfer rate of a solute in a two-liquid system.In particular,fluorescent dye Rhodamine B is considered as the solute.A critical comparison of the situations with and without oscillation is implemented.A procedure is introduced and validated to determine the molecular and effective diffusion coefficients through evaluation of the growth of the diffusion zone width over time.It is shown that,in the presence of the liquid oscillations,there is a significant increase in the width of the zone in which Rhodamine B is present compared to the reference case with no oscillations.The oscillatory flow leads to an intensification of the solute diffusion due to intense time-averaged flows inside the droplet and the surrounding liquid and oscillations of the drop itself.Thestudy is of significant practical interest with particular relevance to typical processes for liquid-liquid extraction.展开更多
The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is...The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is still unclear.Based on the DGT(Diffusive Gradients in Thin-films)technology,this study sets up three moisture control scenarios:continuous wet,wet-dry alternating,and continuous dry,and carries out a 6-month soil moisture control experiment.In the experiment,the DGT device collected the diffusion gradient data of soil selenium under different scenarios,and analyzed the migration characteristics of selenium in combination with the adsorption isotherm.Meanwhile,the release rate,migration coefficient,and bioavailability parameters of selenium are calculated by fitting the first-order kinetic model,further verifying the reliability and applicability of the DGT data.The experimental results demonstrate that under continuous wet conditions,the release rate of soil selenium reaches 1.85µg·cm^(-2)·h^(-1),with a migration coefficient of 0.012 cm^(2)·h^(-1)and a bioavailability parameter of 0.74;under wet-dry alternating conditions,they are 1.42µg·cm^(-2)·h^(-1),0.01 cm^(2)·h^(-1),and 0.68,respectively;under continuous dry conditions,the release rate of soil selenium is the smallest,at 0.88µg·cm^(-2)·h^(-1),with a migration coefficient of 0.004 cm^(-2)·h^(-1)and a bioavailability parameter of 0.5.The results of this experiment reveal the dynamic behavior of soil selenium under different moisture conditions and reflect the high efficiency of DGT technology in dynamic monitoring and quantitative analysis of soil selenium behavior,providing a scientific basis for the optimal management of rhizosphere soil selenium.展开更多
基金supported by the National Natural Science Foundation of China(62073172)the Natural Science Foundation of Jiangsu Province of China(BK20221329)。
文摘Reaction-diffusion systems are widely used to describe pattern formation,and various control strategies have been applied to reaction-diffusion systems to achieve control objectives such as boundary control,output feedback stabilization,and synchronization.However,controlling pattern dynamics in reaction-diffusion systems with fractional-order diffusion remains an unresolved problem.This paper presents a proportional-derivative(PD)control strategy for the Schnakenberg system with fractional-order diffusion and cross-diffusion.Theoretical analysis explores the amplitude equation near the Turing bifurcation threshold,determining the selection and stability of pattern formations.Numerical simulations demonstrate that the PD controller accomplishes the modification of pattern structures and suppression of Turing instability by adjusting only two control parameters.Additionally,it is found that for smaller fractional diffusion order,the region can accommodate more hexagonal and stripe patterns in space.This work contributes to the control of complex pattern dynamics and offers a new approach to enhancing stability in fractional reaction-diffusion systems.
基金supported by the Ministry of Education-Kingdom of Saudi Arabia through the project number 0038-1446-S.
文摘Tangent hyperbolic fluids characterized by shear-thinning behavior,are widely utilized in diverse industrial and scientific fields such as polymer engineering,inkjet printing,biofluids modeling,thermal insulation materials,and chemical manufacturing.Additionally,double-diffusive convection involving simultaneous heat and mass transfer driven by temperature and concentration gradients plays a critical role in many natural and industrial systems,including oceanic circulation,geothermal energy extraction,crystal solidification,alloy formation,and enhanced oil recovery.The current work examines the peristaltic transport of a tangent hyperbolic nanofluid under the concurrent effects of thermal radiation,electroosmotic forces,slip boundary conditions,and double diffusion.The governing nonlinear equations are numerically solved using Mathematica’s NDSolve command after being simplified under the presumptions of a long wavelength,a low Reynolds number,and Debye-Huckel linearization.The analysis reveals that a rise in the velocity slip parameter decreases the core fluid velocity but increases it closer to channel walls,while increased solutal Grashof number and electroosmotic parameter result in non-uniform velocity distributions,reducing the flow towards the left wall and increasing it towards the right.The pressure gradient increases with higher electroosmotic effects and Helmholtz-Smoluchowski velocity,but decreases under more intense thermal radiation and increased Prandtl number.The magnetic field increases pressure in the retrograde area and moves the enhanced zone towards the right wall,emphasizing increased flow resistance.Also,the trapping effects intensify with increasing solutal Grashof number and Helmholtz-Smoluchowski velocity,providing better particle transport and mixing in microfluidic devices.
基金supported by the Singapore Ministry of Educa-tion under Research(Grant no.MOE-T2EP50120-0003).
文摘Emerging bio-inspired computing systems simulate the cognitive functions of the brain for the realiza-tion of future computing systems.For the development of such efficient neuromorphic electronics,the emulation of short-term and long-term synaptic plasticity behaviors of the biological synapses is an es-sential step.However,the electronic synaptic devices suffer from higher variability issues which hinder the application of such devices to build neuromorphic systems.For practical applications,it is essen-tial to minimize the cycle-to-cycle and device-to-device variations in the synaptic functions of artifi-cial electronic synapses.This study involves the fabrication of diffusive memristor devices using WTe_(2) chalcogenide as the main switching material.The choice of the switching material provides a facile so-lution to the variability problem.The greater uniformity in the switching characteristics of the WTe_(2)-based memristor offers higher uniformity for the synaptic emulation.These devices exhibit both volatile and nonvolatile switching properties,allowing them to emulate both short-term and long-term synaptic functions.The WTe_(2)-based electronic synaptic devices present a high degree of uniformity for the emula-tion of various essential biological synaptic functions including short-term potentiation(STP),long-term potentiation(LTP),long-term depression(LTD),spike-rate-dependent plasticity(SRDP),and spike-timing-dependent plasticity(STDP).A higher recognition accuracy of∼92%is attained for pattern recognition using the modified National Institute of Standards and Technology(MNIST)handwritten digits,which is attributed to the enhanced linearity and higher uniformity of LTP/LTD characteristics.
基金supported by the Russian Science Foundation(Grant No.23-11-00242).
文摘An experimental study of the diffusive mass transfer between a droplet and an oscillating immiscible liquid in a horizontal axisymmetricHele-Shaw cell is carried out.Theliquid oscillates radially in the cell.Thetransverse size of the droplet exceeds the cell thickness.The viscosities of the droplet and the surrounding liquid are comparable.Relevant effort is provided to design and test an experimental setup and validate a protocol for determining the mass transfer rate of a solute in a two-liquid system.In particular,fluorescent dye Rhodamine B is considered as the solute.A critical comparison of the situations with and without oscillation is implemented.A procedure is introduced and validated to determine the molecular and effective diffusion coefficients through evaluation of the growth of the diffusion zone width over time.It is shown that,in the presence of the liquid oscillations,there is a significant increase in the width of the zone in which Rhodamine B is present compared to the reference case with no oscillations.The oscillatory flow leads to an intensification of the solute diffusion due to intense time-averaged flows inside the droplet and the surrounding liquid and oscillations of the drop itself.Thestudy is of significant practical interest with particular relevance to typical processes for liquid-liquid extraction.
文摘The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is still unclear.Based on the DGT(Diffusive Gradients in Thin-films)technology,this study sets up three moisture control scenarios:continuous wet,wet-dry alternating,and continuous dry,and carries out a 6-month soil moisture control experiment.In the experiment,the DGT device collected the diffusion gradient data of soil selenium under different scenarios,and analyzed the migration characteristics of selenium in combination with the adsorption isotherm.Meanwhile,the release rate,migration coefficient,and bioavailability parameters of selenium are calculated by fitting the first-order kinetic model,further verifying the reliability and applicability of the DGT data.The experimental results demonstrate that under continuous wet conditions,the release rate of soil selenium reaches 1.85µg·cm^(-2)·h^(-1),with a migration coefficient of 0.012 cm^(2)·h^(-1)and a bioavailability parameter of 0.74;under wet-dry alternating conditions,they are 1.42µg·cm^(-2)·h^(-1),0.01 cm^(2)·h^(-1),and 0.68,respectively;under continuous dry conditions,the release rate of soil selenium is the smallest,at 0.88µg·cm^(-2)·h^(-1),with a migration coefficient of 0.004 cm^(-2)·h^(-1)and a bioavailability parameter of 0.5.The results of this experiment reveal the dynamic behavior of soil selenium under different moisture conditions and reflect the high efficiency of DGT technology in dynamic monitoring and quantitative analysis of soil selenium behavior,providing a scientific basis for the optimal management of rhizosphere soil selenium.
