Three types of composite stringers were impacted from two different directions.Relationships between impact energy and visible defect length were found.The critical impact energy corresponding to barely visible impact...Three types of composite stringers were impacted from two different directions.Relationships between impact energy and visible defect length were found.The critical impact energy corresponding to barely visible impact damage(BVID)of each stringer was determined.Specimens with BVID were then compressed to obtain the residual strength.Experimental results showed that for all types of stringers,the critical energy of in-plane impact is always much lower than out-plane ones.In-plane impact causes much more decrement of stringers'bearing capacity than outplane impact.For both impact directions,I-stringers own the highest defect detectability,T-stringers come second.Meanwhile,I-stringers own the better residual strength ratio than I-stringers and I-stringers.Synthetic considering impact defect detectability and residual bearing capacity after impact,T-stringers own the best compression-afterimpact(CAI)behaviors.展开更多
In the presence of external stimuli and electromagnetic radiation(EMR),biological neurons can exhibit different firing patterns and switch to appropriate firing modes because of intrinsic self-adaption.Coupling to mem...In the presence of external stimuli and electromagnetic radiation(EMR),biological neurons can exhibit different firing patterns and switch to appropriate firing modes because of intrinsic self-adaption.Coupling to memristive synapses can discern the EMR effect,and memristive synapses connecting to neurons can be effectively regulated by external physical fields.From a dynamical viewpoint,the appropriate setting for memristive synapse intensity can trigger changes in neural activities;however,the biophysical mechanism of adaptive regulation in the memristive biophysical neuron has not been clarified.Herein,a memristor is used to control a simple neural circuit by generating a memristive current,and an equivalent memristive neuron model is obtained.A single firing mode can be stabilized in the absence of EMR,while multiple firing modes occur in the neuron under EMR.The gain of the memristive synaptic current is dependent on the energy flow,and the shunted energy flow in the memristive channel can control the energy ratio between the electric field and magnetic field.The growth and enhancement of the memristive synapse depend on the energy flow across the memristive channel.The memristive synapse is enhanced when its field energy is below the threshold,and it is suppressed when its field energy is above the threshold.These results explain why and how multiple firing modes are induced and controlled in biological neurons.Furthermore,the self-adaption property of memristive neurons was also clarified.Thus,the control of energy flow in the memristive synapse can effectively regulate the membrane potentials,and neural activities can be effectively controlled to select suitable body gaits.展开更多
Static charges can induce spatial electric field while moving charges can induce magnetic field.As a result,continuous pumping and exchange of intercellular and extracellular Calcium,potassium and sodium of cells will...Static charges can induce spatial electric field while moving charges can induce magnetic field.As a result,continuous pumping and exchange of intercellular and extracellular Calcium,potassium and sodium of cells will generate time-varying magnetic field in the media.Therefore,the physical effect of electromagnetic induction in neural activities should be included in building biological neurons.On the other hand,the occurrence of action potential and propagation of ions require energy consumption and supply,so the estimation of physical energy becomes important.Based on our memristive biophysical neuron model,the Hamilton energy function is obtained by using the Helmholtz’s theorem,and this energy is contributed by the electric field and magnetic field described by magnetic flux.It is found that this improved neuron model can present the main dynamical properties in neural activities,and it characterizes the lower threshold behavior and subthreshold oscillation during refractory period.The external forcing current on an isolate is adjusted to calculate the firing patterns,energy function and mode transition,which shows the dependence of energy on electrical activities.Finally,magnetic coupling is triggered to modulate the phase synchronization between two identical neurons connected by electric synapse,respectively.展开更多
基金supported in part by the National Key Basic Research and Development Plan (“973”Plan)(No. 613274)Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘Three types of composite stringers were impacted from two different directions.Relationships between impact energy and visible defect length were found.The critical impact energy corresponding to barely visible impact damage(BVID)of each stringer was determined.Specimens with BVID were then compressed to obtain the residual strength.Experimental results showed that for all types of stringers,the critical energy of in-plane impact is always much lower than out-plane ones.In-plane impact causes much more decrement of stringers'bearing capacity than outplane impact.For both impact directions,I-stringers own the highest defect detectability,T-stringers come second.Meanwhile,I-stringers own the better residual strength ratio than I-stringers and I-stringers.Synthetic considering impact defect detectability and residual bearing capacity after impact,T-stringers own the best compression-afterimpact(CAI)behaviors.
基金supported by the National Natural Science Foundation of China(Grant No.12072139)。
文摘In the presence of external stimuli and electromagnetic radiation(EMR),biological neurons can exhibit different firing patterns and switch to appropriate firing modes because of intrinsic self-adaption.Coupling to memristive synapses can discern the EMR effect,and memristive synapses connecting to neurons can be effectively regulated by external physical fields.From a dynamical viewpoint,the appropriate setting for memristive synapse intensity can trigger changes in neural activities;however,the biophysical mechanism of adaptive regulation in the memristive biophysical neuron has not been clarified.Herein,a memristor is used to control a simple neural circuit by generating a memristive current,and an equivalent memristive neuron model is obtained.A single firing mode can be stabilized in the absence of EMR,while multiple firing modes occur in the neuron under EMR.The gain of the memristive synaptic current is dependent on the energy flow,and the shunted energy flow in the memristive channel can control the energy ratio between the electric field and magnetic field.The growth and enhancement of the memristive synapse depend on the energy flow across the memristive channel.The memristive synapse is enhanced when its field energy is below the threshold,and it is suppressed when its field energy is above the threshold.These results explain why and how multiple firing modes are induced and controlled in biological neurons.Furthermore,the self-adaption property of memristive neurons was also clarified.Thus,the control of energy flow in the memristive synapse can effectively regulate the membrane potentials,and neural activities can be effectively controlled to select suitable body gaits.
基金supported partially by the National Natural Science Foundation of China(Grant No.11672122)。
文摘Static charges can induce spatial electric field while moving charges can induce magnetic field.As a result,continuous pumping and exchange of intercellular and extracellular Calcium,potassium and sodium of cells will generate time-varying magnetic field in the media.Therefore,the physical effect of electromagnetic induction in neural activities should be included in building biological neurons.On the other hand,the occurrence of action potential and propagation of ions require energy consumption and supply,so the estimation of physical energy becomes important.Based on our memristive biophysical neuron model,the Hamilton energy function is obtained by using the Helmholtz’s theorem,and this energy is contributed by the electric field and magnetic field described by magnetic flux.It is found that this improved neuron model can present the main dynamical properties in neural activities,and it characterizes the lower threshold behavior and subthreshold oscillation during refractory period.The external forcing current on an isolate is adjusted to calculate the firing patterns,energy function and mode transition,which shows the dependence of energy on electrical activities.Finally,magnetic coupling is triggered to modulate the phase synchronization between two identical neurons connected by electric synapse,respectively.
