Using anomalous X-ray scattering, kinetics of X-ray diffuse scattering in an Al70Ni15Co15 decagonal quasicrystal was investigated at fixed temperature （807℃）. Short-range order diffuse scattering from the single qu...Using anomalous X-ray scattering, kinetics of X-ray diffuse scattering in an Al70Ni15Co15 decagonal quasicrystal was investigated at fixed temperature （807℃）. Short-range order diffuse scattering from the single quasicrystal disappeared gradually on time scale. At the same time, some extra weak Debye rings appeared near the Bragg reflection. The volume of the polycrystallization is quite small due from the intensity ratio of weak powder patterns to the Bragg reflection. The extremely weak Debye rings were observed only near the Co K-edge. By the Co enhancement using anomalous X-ray scattering, we might probe the local movement of Co atoms in the skin layer as well as Al enrichment and Co depletion on the surface of decagonal Al65Co20Cu15.展开更多
The signals and the neuronal mechanisms that underlying the behavior, actions, and action-directed goals in man and animals during conscious state are not fully understood, and the neuro-dynamic mechanisms and the sou...The signals and the neuronal mechanisms that underlying the behavior, actions, and action-directed goals in man and animals during conscious state are not fully understood, and the neuro-dynamic mechanisms and the source of these neuronal signals are not authenticated. Temporal judgment alone can neither account for neural signaling necessary for emergence of conscious act nor explain RP （Readiness Potential, the accepted neural correlate time needed for the neurons to fire） that precedes the onset of action or the latency time of 0.5 ms that precedes the conscious act found by Libet. Neuronal feedback mechanisms between the heart and the brain seem feasible and logical suggestions to be considered, so clearly, I would suggest that the onset of a conscious-directed goal, conscious action, freewill, intension, and the neural signals and mechanisms that control them may depend upon the interaction between two sources： （1） the brain and （2） the heart. The temporal-cardiac （neural system） interaction has been well established in heart-brain interaction studies by many workers who found that the work of the heart precedes that of the brain in EEG （electroencephalography） findings in conscious stimulation, which may explain and account for RP time and the 0.5 ms latency period of Libet＇s important findings. According to my hypothesis （AlFaki 2009） and views, the temporal neurons in the soma to-sensory cortex will respond to conscious stimulation only after receiving neuronal signals from the cardiac neurons in the neural plexus of the heart; after variable millisecond equivalent to RP or Libet＇s latency period prior to temporal neuronal firinging in response to conscious act, this time is the time needed by cardiac neurons to process and signal information to the brain through feedback mechanism and heart-brain interaction.展开更多
Objective To investigate the spike activities of cerebellar cortical cells in a computational network model con- structed based on the anatomical structure of cerebellar cortex. Methods and Results The multicompartmen...Objective To investigate the spike activities of cerebellar cortical cells in a computational network model con- structed based on the anatomical structure of cerebellar cortex. Methods and Results The multicompartment model of neuron and NEURON software were used to study the external influences on cerebellar cortical cells. Various potential spike patterns in these cells were obtained. By analyzing the impacts of different incoming stimuli on the potential spike of Purkinje cell, temporal focusing caused by the granule cell-golgi cell feedback inhibitory loop to Purkinje cell and spa- tial focusing caused by the parallel fiber-basket/stellate cell local inhibitory loop to Purkinje cell were discussed. Finally, the motor learning process of rabbit eye blink conditioned reflex was demonstrated in this model. The simulation results showed that when the afferent from climbing fiber existed, rabbit adaptation to eye blinking gradually became stable under the Spike Timing-Dependent Plasticity （STDP） learning rule. Conclusion The constructed cerebellar cortex network is a reliable and feasible model. The model simulation results confirmed the output signal stability of cerebellar cortex after STDP learning and the network can execute the function of spatial and temporal focusing.展开更多
文摘Using anomalous X-ray scattering, kinetics of X-ray diffuse scattering in an Al70Ni15Co15 decagonal quasicrystal was investigated at fixed temperature （807℃）. Short-range order diffuse scattering from the single quasicrystal disappeared gradually on time scale. At the same time, some extra weak Debye rings appeared near the Bragg reflection. The volume of the polycrystallization is quite small due from the intensity ratio of weak powder patterns to the Bragg reflection. The extremely weak Debye rings were observed only near the Co K-edge. By the Co enhancement using anomalous X-ray scattering, we might probe the local movement of Co atoms in the skin layer as well as Al enrichment and Co depletion on the surface of decagonal Al65Co20Cu15.
文摘The signals and the neuronal mechanisms that underlying the behavior, actions, and action-directed goals in man and animals during conscious state are not fully understood, and the neuro-dynamic mechanisms and the source of these neuronal signals are not authenticated. Temporal judgment alone can neither account for neural signaling necessary for emergence of conscious act nor explain RP （Readiness Potential, the accepted neural correlate time needed for the neurons to fire） that precedes the onset of action or the latency time of 0.5 ms that precedes the conscious act found by Libet. Neuronal feedback mechanisms between the heart and the brain seem feasible and logical suggestions to be considered, so clearly, I would suggest that the onset of a conscious-directed goal, conscious action, freewill, intension, and the neural signals and mechanisms that control them may depend upon the interaction between two sources： （1） the brain and （2） the heart. The temporal-cardiac （neural system） interaction has been well established in heart-brain interaction studies by many workers who found that the work of the heart precedes that of the brain in EEG （electroencephalography） findings in conscious stimulation, which may explain and account for RP time and the 0.5 ms latency period of Libet＇s important findings. According to my hypothesis （AlFaki 2009） and views, the temporal neurons in the soma to-sensory cortex will respond to conscious stimulation only after receiving neuronal signals from the cardiac neurons in the neural plexus of the heart; after variable millisecond equivalent to RP or Libet＇s latency period prior to temporal neuronal firinging in response to conscious act, this time is the time needed by cardiac neurons to process and signal information to the brain through feedback mechanism and heart-brain interaction.
基金supported by the grants from National Natural Science Foundation of China (No. 10872069)
文摘Objective To investigate the spike activities of cerebellar cortical cells in a computational network model con- structed based on the anatomical structure of cerebellar cortex. Methods and Results The multicompartment model of neuron and NEURON software were used to study the external influences on cerebellar cortical cells. Various potential spike patterns in these cells were obtained. By analyzing the impacts of different incoming stimuli on the potential spike of Purkinje cell, temporal focusing caused by the granule cell-golgi cell feedback inhibitory loop to Purkinje cell and spa- tial focusing caused by the parallel fiber-basket/stellate cell local inhibitory loop to Purkinje cell were discussed. Finally, the motor learning process of rabbit eye blink conditioned reflex was demonstrated in this model. The simulation results showed that when the afferent from climbing fiber existed, rabbit adaptation to eye blinking gradually became stable under the Spike Timing-Dependent Plasticity （STDP） learning rule. Conclusion The constructed cerebellar cortex network is a reliable and feasible model. The model simulation results confirmed the output signal stability of cerebellar cortex after STDP learning and the network can execute the function of spatial and temporal focusing.
