排序方式: 共有28条查询结果,搜索用时 375 毫秒
21.
A chaotic firing pattern, characterized by non-smooth features and generated through the routine of intermittency from period 3, is observed in biological experiments on a neural firing pacemaker and reproduced in simulations by using a theoretical neuronal model with multiple time scales. This chaotic activity exhibits a scale law very similar to those of both the type-Ⅰ intermitteney generated in smooth systems and the type-Ⅴ intermittency in non-smooth systems. 相似文献
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本文通过非微扰求解薛定谔方程, 研究了强磁场磁化的等离子体环境中的原子能级结构和辐射动力学过程. 在较宽的磁场强度范围和等离子体屏蔽参数范围内, 给出了氢原子基态以及低激发态的能级、辐射跃迁能量和振子强度等重要的原子参数, 定量地描述了强磁场和等离子体屏蔽共同作用的综合效应. 相关的结果有助于增进对极端环境下原子光谱结构的认识, 在等离子体光谱诊断和天文光谱观测方面有一定的借鉴意义.
关键词:
强磁场
CWDVR谱方法
能级结构
振子强度 相似文献
23.
In this paper we present
the analytic expressions of partition lines in the parametric space of a piece-wise smooth
mapping describing an electronic relaxation oscillator. The supercritical regions with
permission of period-doubling bifurcation, prohibition of period-doubling bifurcation, and
complete phase-locking are discussed. Among them the region, where period-doubling
bifurcation is prohibited but chaos is permitted is reported for the first time to our
knowledge. These kinds of phenomena and regions can be observed in a lot of similar
systems. 相似文献
24.
Bifurcation diagram globally underpinning neuronal firing behaviors modified by SK conductance 下载免费PDF全文
Neurons in the brain utilize various firing trains to encode the input signals they have received.Firing behavior of one single neuron is thoroughly explained by using a bifurcation diagram from polarized resting to firing,and then to depolarized resting.This explanation provides an important theoretical principle for understanding neuronal biophysical behaviors.This paper reports the novel experimental and modeling results of the modification of such a bifurcation diagram by adjusting small conductance potassium(SK)channel.In experiments,changes in excitability and depolarization block in nucleus accumbens shell and medium-spiny projection neurons are explored by increasing the intensity of injected current and blocking the SK channels by apamin.A shift of bifurcation points is observed.Then,a Hodgkin–Huxley type model including the main electrophysiological processes of such neurons is developed to reproduce the experimental results.The reduction of SK channel conductance also shifts the bifurcations,which is in consistence with experiment.A global bifurcation paradigm of this shift is obtained by adjusting two parameters,intensity of injected current and SK channel conductance.This work reveals the dynamics underpinning modulation of neuronal firing behaviors by biologically important ionic conductance.The results indicate that small ionic conductance other than that responsible for spike generation can modify bifurcation points and shift the bifurcation diagram and,thus,change neuronal excitability and adaptation. 相似文献
25.
本文报导了在一个既不连续又不可逆分段线性映象中,由“边界碰撞分岔”所导致之周期轨道的魔梯结构,及由此产生的V型阵发的特征,得到了绕数、李雅普诺夫指数和平均层流层相长度与控制参数的关系,以及重注入点分布的解析和数值结果。当控制参数ε→0时,绕数和李指数以1/1nε规律变化,而平均层流相长度却满足1nε标度律。本文所得结果与电张驰振子的实验结果很好地符合。 相似文献
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The phase order in a one-dimensional(1 D) piecewise linear discontinuous map is investigated. The striking feature is that the phase order may be ordered or disordered in multi-band chaotic regimes, in contrast to the ordered phase in continuous systems. We carried out an analysis to illuminate the underlying mechanism for the emergence of the disordered phase in multi-band chaotic regimes, and proved that the phase order is sensitive to the density distribution of the trajectories of the attractors. The scaling behavior of the net direction phase at a transition point is observed. The analytical proof of this scaling relation is obtained. Both the numerical and analytical results show that the exponent is 1, which is controlled by the feature of the map independent on whether the system is continuous or discontinuous. It extends the universality of the scaling behavior to systems with discontinuity. The result in this work is important to understanding the property of chaotic motion in discontinuous systems. 相似文献
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