This study investigates the bifurcation dynamics underlying rhythmic transitions in a biophysical hippocampal–cortical neural network model.We specifically focus on the membrane potential dynamics of excitatory neuro...This study investigates the bifurcation dynamics underlying rhythmic transitions in a biophysical hippocampal–cortical neural network model.We specifically focus on the membrane potential dynamics of excitatory neurons in the hippocampal CA3 region and examine how strong coupling parameters modulate memory consolidation processes.Employing bifurcation analysis,we systematically characterize the model's complex dynamical behaviors.Subsequently,a characteristic waveform recognition algorithm enables precise feature extraction and automated detection of hippocampal sharp-wave ripples(SWRs).Our results demonstrate that neuronal rhythms exhibit a propensity for abrupt transitions near bifurcation points,facilitating the emergence of SWRs.Critically,temporal rhythmic analysis reveals that the occurrence of a bifurcation is not always sufficient for SWR formation.By integrating one-parameter bifurcation analysis with extremum analysis,we demonstrate that large-amplitude membrane potential oscillations near bifurcation points are highly conducive to SWR generation.This research elucidates the mechanistic link between changes in neuronal self-connection parameters and the evolution of rhythmic characteristics,providing deeper insights into the role of dynamical behavior in memory consolidation.展开更多
According to Newton's Second Law and the microwave theory,mechanical analysis of multiple buoys which form Sharp Eagle wave energy converter(WEC)is carried out.The movements of every buoy in three modes couple eac...According to Newton's Second Law and the microwave theory,mechanical analysis of multiple buoys which form Sharp Eagle wave energy converter(WEC)is carried out.The movements of every buoy in three modes couple each other when they are affected with incident waves.Based on the above,mechanical models of the WEC are established,which are concerned with fluid forces,damping forces,hinge forces,and so on.Hydrodynamic parameters of one buoy are obtained by taking the other moving buoy as boundary conditions.Then,by taking those hydrodynamic parameters into the mechanical models,the optimum external damping and optimal capture width ratio are calculated out.Under the condition of the optimum external damping,a plenty of data are obtained,such as the displacements amplitude of each buoy in three modes(sway,heave,pitch),damping forces,hinge forces,and speed of the hydraulic cylinder.Research results provide theoretical references and basis for Sharp Eagle WECs in the design and manufacture.展开更多
The " Sharp Eagle” device is a wave energy converter of a hinged double floating body. The wave-absorbing floating body hinges on the semi-submerged floating body structure. Under the action of wave, the wave-ab...The " Sharp Eagle” device is a wave energy converter of a hinged double floating body. The wave-absorbing floating body hinges on the semi-submerged floating body structure. Under the action of wave, the wave-absorbing floating body rotates around the hinge point, and the wave energy can be converted into kinetic energy. In this paper, the power take-off system of " Sharp Eagle Ⅱ” wave energy converter (the second generation of " Sharp Eagle”) was studied, which adopts the hydraulic type power take-off system. The 0-1 power generation mode was applied in this system to make the " Sharp Eagle Ⅱ” operate under various wave conditions. The principle of power generation was introduced in detail, and the power take-off system was simulated. Three groups of different movement period inputs were used to simulate three kinds of wave conditions, and the simulation results were obtained under three different working conditions. In addition, the prototype of " Sharp Eagle Ⅱ” wave energy converter was tested on land and in real sea conditions. The experimental data have been collected, and the experimental data and simulation results were compared and validated. This work has laid a foundation for the design and application of the following " Sharp Eagle” series of devices.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12272002 and 12372061)the R&D Program of Beijing Municipal Education Commission(Grant No.KM202310009004)+1 种基金the North China University of Technology(Grant No.2023XN075-01)the Youth Research Special Project of the North China University of Technology(Grant No.2025NCUTYRSP051)。
文摘This study investigates the bifurcation dynamics underlying rhythmic transitions in a biophysical hippocampal–cortical neural network model.We specifically focus on the membrane potential dynamics of excitatory neurons in the hippocampal CA3 region and examine how strong coupling parameters modulate memory consolidation processes.Employing bifurcation analysis,we systematically characterize the model's complex dynamical behaviors.Subsequently,a characteristic waveform recognition algorithm enables precise feature extraction and automated detection of hippocampal sharp-wave ripples(SWRs).Our results demonstrate that neuronal rhythms exhibit a propensity for abrupt transitions near bifurcation points,facilitating the emergence of SWRs.Critically,temporal rhythmic analysis reveals that the occurrence of a bifurcation is not always sufficient for SWR formation.By integrating one-parameter bifurcation analysis with extremum analysis,we demonstrate that large-amplitude membrane potential oscillations near bifurcation points are highly conducive to SWR generation.This research elucidates the mechanistic link between changes in neuronal self-connection parameters and the evolution of rhythmic characteristics,providing deeper insights into the role of dynamical behavior in memory consolidation.
基金supported by the National Natural Science Foundation of China(Grant No.41406102)the Special Foundation for Ocean Renewable Energy(Grant No.GHME2016YY01)
文摘According to Newton's Second Law and the microwave theory,mechanical analysis of multiple buoys which form Sharp Eagle wave energy converter(WEC)is carried out.The movements of every buoy in three modes couple each other when they are affected with incident waves.Based on the above,mechanical models of the WEC are established,which are concerned with fluid forces,damping forces,hinge forces,and so on.Hydrodynamic parameters of one buoy are obtained by taking the other moving buoy as boundary conditions.Then,by taking those hydrodynamic parameters into the mechanical models,the optimum external damping and optimal capture width ratio are calculated out.Under the condition of the optimum external damping,a plenty of data are obtained,such as the displacements amplitude of each buoy in three modes(sway,heave,pitch),damping forces,hinge forces,and speed of the hydraulic cylinder.Research results provide theoretical references and basis for Sharp Eagle WECs in the design and manufacture.
基金financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA13040202)the Special Funding Program for Marine Renewable Energy of the State Oceanic Administration(Grant No.GHME2017SF01)
文摘The " Sharp Eagle” device is a wave energy converter of a hinged double floating body. The wave-absorbing floating body hinges on the semi-submerged floating body structure. Under the action of wave, the wave-absorbing floating body rotates around the hinge point, and the wave energy can be converted into kinetic energy. In this paper, the power take-off system of " Sharp Eagle Ⅱ” wave energy converter (the second generation of " Sharp Eagle”) was studied, which adopts the hydraulic type power take-off system. The 0-1 power generation mode was applied in this system to make the " Sharp Eagle Ⅱ” operate under various wave conditions. The principle of power generation was introduced in detail, and the power take-off system was simulated. Three groups of different movement period inputs were used to simulate three kinds of wave conditions, and the simulation results were obtained under three different working conditions. In addition, the prototype of " Sharp Eagle Ⅱ” wave energy converter was tested on land and in real sea conditions. The experimental data have been collected, and the experimental data and simulation results were compared and validated. This work has laid a foundation for the design and application of the following " Sharp Eagle” series of devices.
基金the Program of Shanghai Academic Research Leader(No.19XD1423300)Shanghai Municipal Commission of Education—Gaofeng Clinical Medicine Grant Support(No.20191835)。
