Pattern discrimination and firing behavior of cold receptor model aided with noise

A method for characterizing and identifying firing patterns of neural spike trains is presented. Three characteristic variables defined at sequential moments, including two formal derivatives and the integration of the counting process, are introduced to reflect the temporal patterns of a spike train. This paper also examines how noise interacts with encoding mechanisms of neuronal stimulus in a cold receptor. From ISI series and bifurcation diagrams it is shown that there are considerable differences in interval distributions and impulse patterns caused by purely deterministic simulations and noisy simulations. The ISI-distance can be used as an effective and powerful way to measure the noise effects on spike trains quantitatively. It is found that spike trains observed in cold receptors can be more strongly affected by noise for low temperatures than for high temperatures in some aspects; meanwhile, spike train has greater variability with the noise intensity increasing.     

稀土化合物RX的晶场参数分析

本文对NaCl型结构的稀土化合物RX(X=N,P,As,Sb,Bi)的晶场参数B₄⁰的实验值进行了分析。在此基础上我们提出一个新的利用简单点电荷模型计算RX晶场参数B₄⁰值的关系式:B₄⁰=k₃(B₄⁰)_p+c₃。用此关系式我们确定了一系列RX的晶场参数B₄⁰值,结果与实验值符合很好。对关系式的含义本文也作了充分讨论。 关键词：     

钙钛矿结构中的简谐子软模

利用复合空间型方法,在自由边界条件下解出了钙钛矿结构有限尺寸晶体的简谐振动方程.计算结果给出了收敛的简谐子谱分布,并发现了许多简谐子软模.用这些软模花样说明了钛酸钡晶体冷却时发生具有a畴和c畴结构的铁电相变.理论表明铁电相变过程涉及屏蔽电荷的激发及其在界面的缓慢扩散,以最后得出各个电畴内部的均匀自发极化 关键词： 晶格动力学 简谐子 软模 钛酸钡     

A simple method improving the analyzing accuracy of circular groove guide

A simple method is introduced to improve the analysing accuracy of circular groove guide. With this method, the characteristic equation of circular groove guide is derived and its solution is given and discussed.The Project Supported by National Natural Science Foundation of P.R.China     

Zn1-xCdxSe-ZnSe多量子阱的光学双稳态

用常压MOCVD法在GaAs衬底上生长了Zn_1-xCd_xSe-ZnSe多层结构.通过X-射线衍射谱和光致发光等方法判断,表明该材料为多量子阱结构.从室温下的透射光谱上可以观察到这种多量子阱中的n=1的激子吸收峰,并观测到起因子激子的ns量级的光学双稳态.     

超短光脉冲作用下的二能级原子

考虑到光场的振幅随时间分布的影响时,我们重新研究了光场与二能级原子相互作用的跃迁几率问题。在强光信号作用下,经过一定的数学代换后,上能级几率的求解可归结为类希尔方程求解;在弱光信号作用下,利用转动波近似(RWA),给出了二能级原子跃迁几率的解析表达式,并讨论了几种典型脉冲光场的分布。