Anti-synchronization Between Lorenz and Liu Hyperchaotic Systems

Anti-synchronization between different hyperchaotic systems is presented using Lorenz and Liu systems. When the parameters of two systems are known, one can use active synchronization. When the parameters are unknown or uncertain, the adaptive synchronization is applied. The simulation results verify the effectiveness of the proposed two schemes for anti-synchronization between different hyperchaotic systems.

Heteroatom self-doped graphitic carbon materials from Sargassum thunbergii with improved supercapacitance performance

It is well-known that high specific surface area and improved pore structure is significantly desired for the application of supercapacitor based on biomass-based activated carbon.Herein,Sargassum thunbergii was selected as carbon precursor.Then,a simple and environmentally friendly method was designed to synthesize heteroatom self-doped porous carbon materials via synchronous activation and graphitization by using K_(2)FeO_(4).Our results demonstrated that activation temperature plays an important role in porous structure,morphology,and degree of graphitization,thus affecting the performance of supercapacitance.Sargassum thunbergii-based graphitized porous carbons STGPC-2 sample(calcination temperature at 700℃)has a large specific surface area(1641.98 m^(2)g^(-1)),pore volume(0.91 cm^(3)g^(-1)),high microporosity(Vmicro=0.62 cm^(3)g1,more than 68%),and a certain degree of graphitization.In three-electrode system,The STGPC-2 electrode exhibited a high specific capacitance of 325.5 F g^(-1)at 0.5 A g^(-1)and displays high rate capability(248 F g^(-1)at 10 A g^(-1)in 6 M KOH electrolyte).The symmetric STGPC-2 supercapacitor exhibits energy density as high as 21.3 Wh kg^(-1)(at a power density of 450 W kg^(-1))and excellent long-term cycling stability(97%capacitance retention after 3000 cycles)in 1 M Na2SO4 electrolyte.

Influence of GABAergic Pathway on Retinal Adaptation-Related Response Changes

Retinal ganglion cells(RGCs) exhibit adaptive changes in response to sustained light stimulation,which include decrease in firing rate, tendency to shrink in receptive field(RF) size and reduction in synchronized activities. Gamma-aminobutyric acid-ergic(GABAergic) pathway is an important inhibitory pathway in retina.In the present study, the effects of GABAergic pathway on the contrast adaptation process of bullfrog RGCs were studied using multi-electrode recording technique. It was found that the application of bicuculline(BIC), a gamma-aminobutyric acid A(GABAA) receptor antagonist, caused a number of changes in the RGCs' response characteristics, including attenuation in adaptation-dependent firing rate decrease and the adaptation-dependent weakening in synchronized activities between adjacent neuron-pairs, whereas intensified the adaptation-dependent RF size shrinkage. These results suggest that GABAAreceptors are involved in the modulation of the firing activity and synchronized activities in contrast adaptation process of the RGCs, whereas the adaptation-related RF property changes involve more complicated mechanisms.

Active Power Reserve Photovoltaic Virtual Synchronization Control Technology

The photovoltaic virtual synchronous generator(PV-VSG)solves the problem of lack of inertia in the PV power-generation system.The existing PV plants without energy storage are required to participate in the power grid’s frequency modulation(FM),but existing PV-VSGs with energy storage have high requirements for coordinated control.Therefore,the active power reserve PV-VSG(APR-PV-VSG)is studied.Based on the different methods to obtain the maximum power point(MPP),the peer-to-peer and master-slave APR-PV-VSG strategies are proposed.The PV inverters are deviated from the MPP to reserve active power,which is used as the virtual inertia and primary FM power.These methods equip the PV power station with FM capability.The effectiveness of the proposed control strategies is verified by simulation results.

Stimulus discrimination via responses of retinal ganglion cells and dopamine-dependent modulation

Neighboring retinal ganglion cells（RGCs）fire with a high degree of correlation.It has been increasingly realized that visual perception of the environment relies on neuronal population activity to encode and transmit the information contained in stimuli.Understanding how neuronal population activity contributes to visual information processing is essential for understanding the mechanisms of visual coding.Here we simultaneously recorded spike discharges from groups of RGCs in bullfrog retina in response to visual patterns（checkerboard,horizontal grating,and full-field illumination）using a multi-electrode array system.To determine the role of synchronous activity mediated by gap junctions,we measured the correct classification rates of single cells＇firing patterns as well as the synchronization patterns of multiple neurons.We found that,under normal conditions,RGC population activity exhibited distinct response features with exposure to different stimulus patterns and had a higher rate of correct stimulus discrimination than the activity of single cells.Dopamine（1μmol/L）application did not significantly change the performance of single neuron activity,but enhanced the synchronization of the RGC population activity and decreased the rate of correct stimulus pattern discrimination.These findings suggest that the synchronous activity of RGCs plays an important role in the information coding of different types of visual patterns,and a dopamine-induced increase in synchronous activity weakens the population performance in pattern discrimination,indicating the potential role of the dopaminergic pathway in modulating the population coding process.