The effects of rises in external K+ on the hyperpolarization-activated cation current Ih in rat dorsal root ganglion neurons

The effects of rises in external K⁺ (K_ext) were examined on the hyperpolarization-activated cation current (I _h) in rat dorsal root ganglion neurons using the whole-cell patch clamp technique. The results showed that K_ext increased I _h in a certain concentration and voltage-dependent manner. At the basal K_ext level (4 mmol/L), I _h had a maximal amplitude of 1085 ± 340 pA which was enhanced by ∼45% and ∼92% at 8 and 16 mmol/L K_ext, respectively. The midpoint activation voltage was significantly shifted from −98 mV in the hyperpolarizing direction by 8 and 12 mV at 8 and 16 mmol/L K_ext, respectively with alteration of the activation course of I _h. The short time constants of activation became longer with the increasing amplitude of the command potential upon rises in K_ext. The long time constants became shorter. The reversal potentials were shifted in the positive direction without significant alterations upon rises in K_ext. According to the functional role of I _h, K_ext increased I _h, resulting in an enhanced neuronal excitability, which might produce activation potential abnormality and perhaps neuropathic pain involved. Supported by the University of Science and Technology Foundation of Shanxi Province (Grant No. 200713010)     

无重复因析试验中一种估计散度效应的方法

自从Box和Meyer首次提出无重复因析试验中散度效应的识别和估计问题, 各种散度效应的估计方法(包括迭代和非迭代)被提出. 特别地, Brenneman 和Nair 给出了这些方法的一个综述, 并且他们验证了改进的Harvey方法优于其它的方法.本文中对于对数线性模型, 一个基于多个位置模型残差平均的非迭代的散度效应估计方法在模型选择阶段被提出. 在大多数的模拟实验模型中, 本文方法具有比MH方法更小的均方误差, 且它可以应用于MH方法不适用的0或小的绝对残差情形. 我们也考虑了这个估计的理论性质, 并进行了实例分析.     

发光材料中间体2-溴芴酮的合成与表征

以芴酮为原料,通过溴代反应制备得到2-溴芴酮,并对反应条件进行了优化选择。实验结果表明较佳反应条件为：水作为溶剂,芴酮与溴的摩尔比为1∶1.2,85℃下反应3h,所得2-溴芴酮的产率为93.28%,纯度质量分数高于98.0%。产物结构通过了红外、核磁波谱的表征。     

Smooth and non-smooth travelling waves in a nonlinearly dispersive Boussinesq equation

The dynamical behavior and special exact solutions of nonlinear dispersive Boussinesq equation (B(m,n) equation), u_tt−u_xx−a(uⁿ)_xx+b(u^m)_xxxx=0, is studied by using bifurcation theory of dynamical system. As a result, all possible phase portraits in the parametric space for the travelling wave system, solitary wave, kink and anti-kink wave solutions and uncountably infinite many smooth and non-smooth periodic wave solutions are obtained. It can be shown that the existence of singular straight line in the travelling wave system is the reason why smooth waves converge to cusp waves, finally. When parameter are varied, under different parametric conditions, various sufficient conditions guarantee the existence of the above solutions are given.     

Abel群的一些分解定理的推广(Ⅲ)

从主理想整环上有界模分解的Prüfer-Baer定理出发,研究(无限维)向量空间的代数的线性变换的几个基本问题,得到了如下结果:设V是域F上的(无限维)向量空间,A是V上的一个代数的线性变换,则有(1)若任何与A可交换的线性变换均与线性变换B可交换,则B=f(A),其中f是F上的多项式.进而线性变换B也是代数的.(2) V中存在一组基,使A在这组基下的矩阵是有理标准型(经典标准型)矩阵.当F是代数闭域时,经典标准型矩阵即为若当标准型矩阵.(3)当F是代数闭域时,A存在相应的Jordan-Chevalley分解.进一步,该结论在完全域上仍成立.这些研究推广了有限维向量空间上线性变换的相关结果.     

企业受金融危机影响的数学模型

在各种不同的背景下,建立了一系列企业受金融危机影响的微分方程模型,应用微分方程稳定性理论研究了企业受金融危机影响的变化规律及其稳定性.改进了最近的一些结果.     

子群为拟正规或自正规的有限群

本文研究了每个子群为拟正规或自正规的有限群，给出了这类群的完全分类，主要结果为定理Ｇ的每个子群为拟正规或自正规当且仅当Ｇ为下列情形之一：Ⅰ）Ｇ为拟Ｈａｍｉｌｔｏｎ群，Ⅱ）Ｇ＝ＨＰ，其中Ｈ为Ｇ的正规ａｂｅｌｉａｎｐ＇－Ｈａｌｌ子群．Ｐ＝〈ｘ〉∈Ｓｙｌ＿ｐ（Ｇ）。〈ｘ￣ｐ〉＝Ｏ＿ｐ（Ｇ）＝Ｚ（Ｇ），ｘ在Ｈ上诱导Ｈ的一个ｐ阶无不动点的幂自同构．ｐ为｜Ｇ｜的最小素因子。由此定理可得文［１］所获得的定理。     

Cahn-Hilliard方程非条件能量稳定二阶方法的稳定性和收敛性分析

在这项工作中,我们构建了一种非条件能量稳定的高效不变能量四分法(IEQ)来求解Cahn-Hilliard方程.所构建的数值格式是线性的、具有二阶时间精度和非条件能量稳定性.我们仔细分析了数值格式的唯一可解性、稳定性和误差估计.结果表明,所构建的格式满足唯一可解性、非条件能量稳定性和时间方向的二阶收敛性.通过大量的二维和三维数值实验,我们进一步验证了所提出格式的收敛阶、非条件能量稳定性和有效性.     

Nonlinear Schr?dinger Approximation for the Electron Euler-Poisson Equation

The nonlinear Schr?dinger(NLS for short) equation plays an important role in describing slow modulations in time and space of an underlying spatially and temporarily oscillating wave packet. In this paper, the authors study the NLS approximation by providing rigorous error estimates in Sobolev spaces for the electron Euler-Poisson equation,an important model to describe Langmuir waves in a plasma. They derive an approximate wave packet-like solution to the evolution equations by the multiscale a...