几类具有无穷时滞泛函微分方程正周期解的存在性

运用Leray-Schauder不动点定理研究具有无穷时滞的泛函微分方程的正周期解的存在性问题,获得了存在正周期解的充分条件,改进了文献[3]中的结果.     

一类高维脉冲泛函微分方程周期解的存在性(英文)

使用Leray-Schauder不动点定理研究一类高维脉冲泛函微分方程的正周期解的存在性,获得了该类方程存在正周期解的充分条件,改进了已知文献中的结果.     

一类非线性Lotka-Volterra系统的正概周期解

通过变换和不动点定理,研究了一类非线性Lotka-Volterra系统的正概周期解的存在性,获得了新的结果．     

脉冲微分方程正周期解的存在唯一性与全局吸引性（英文）

本文,我们考虑了脉冲微分方程.正周期解的存在唯一性与全局吸引性,通过使用不动点定理,建立了该方程唯一正周期解的存在性与全局吸引性的充分条件.特别地,我们给出x是其他正解的全局吸引子.我们的结果推广和改进了已有文献结果.     

具有无穷时滞的一个捕食者-两个竞争被捕食者生态动力学模型的动力学研究（英文）

提出了一类具有时滞的一个捕食者一两个竞争被捕食者生态动力学模型.首先,利用Krasnoselskii不动点定理研究了系统的正周期解的存在性;然后通过构造Lyapunov函数方法获得了正周期解全局收敛的一个充分条件:最后.给出一个例子以验证理论结果的正确性.     

关于非线性互惠共存生物动力系统解的性态

本文研究了非线性互惠共存生物动力系统在周期环境中解的性态,运用了比较原理,Ｂｒｏｕｗｅｒ不动点定理,锥域上的单调、强正、强凹算子等方法,得到周期解的存在唯一性,并证明了该周期解是全局一致渐近稳定的。     

一类具有无穷时滞的不连续Lasota-Wazewska模型及其伪概周期性

本文研究了一类具有无穷时滞的不连续Lasota-Wazewska模型及其伪概周期性.首先利用指数二分性和不动点定理证明该系统伪概周期解的存在唯一性,然后通过构造恰当的Lyapunov函数得到伪概周期解的指数收敛性.最后,给出一个实例验证本文结论的可行性.     

一类食饵具有S-型变收获率的非自治离散捕食系统渐近行为

建立并研究了一类具有S-型变收获率的非自治离散捕食系统,应用差分不等式、Brouwer不动点定理和分析技巧分别建立了系统的持久生存性,正周期解的存在性及全局渐近稳定性的充分条件,我们还给出了具体验证例子及相应的数值模拟结果.     

一类分数阶微分方程边值问题的多重正解

应用Guo-Krasnosel’skii不动点定理得到了边值问题(1)正解的存在性,利用锥不动点等定理证明一类分数阶微分方程边值问题(1)多重正解的存在性,推广了文献[1]的结果.     

具常数时滞细胞神经网络概周期解

利用矩阵不等式的分析技巧和Banach空间中不动点定理,得到了具常数时滞细胞神经网络概周期解的存在性、唯一性和全局指数稳定性,推广和改进了已有文献的结论。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism