4∶1粘弹性收缩流动中纤维取向研究

利用纤维生成算法,研究了4∶1粘弹性收缩流动中的纤维取向。直接在流场中生成纤维,通过求解Jeffery方程,得到纤维在流场中的取向状态。结果表明在4∶1平板收缩流中,在靠近壁面且远离拐角的区域,流场中主要是剪切作用占主导地位,而纤维呈现周期性旋转状态;在接近中轴线的位置,流场中转变为拉伸作用占主导地位,纤维沿单轴拉伸;在在上游拐角区域和收缩入口处,流动相对复杂,纤维的取向也相对复杂,因为流动以旋转为主,所以纤维取向也随着出现不规则旋转。     

一种自适应混合遗传算法在求解病态线性方程组中的应用

简单遗传算法（SGA）在进化的后期由于种群个体的多样性急剧降低,可能会收敛于局部最优解,即出现“早熟”现象。针对简单遗传算法的早熟问题,从选择、交叉和变异三个遗传算子入手,设计了自适应遗传算子。同时为了克服SGA局部搜索能力差的缺点,结合共轭梯度法,实现了一种自适应混合遗传算法（Adaptive GA-conjugate gradient,即AGA-CG）。以核磁共振测井曲线线性化后的大型病态方程组为测试实例,对AGA-CG算法进行了验证。实验结果表明：AGA-CG算法是求解大型病态线性方程组的一种有效算法。     

Petersen图中包含给定边集的最长圈及其在3－正则图中的应用

给出了Petersen图中包含给定边集的最长圈的结果及该结果在3-连通、3-正则图中的应用；最后提出两个问题。     

Fractals generated by statistical contraction operators

In the theory of random fractal, there are two important classes of random sets, one is the class of fractals generated by the paths of stochastic processes and another one is the class of factals generated by statistical contraction operators. Now we will introduce some things about the probability basis and fractal properties of fractals in the last class. The probability basis contains (1) the convergence and measurability of a random recursive set K(ω) as a random element, (2) martingals property. The fractal properties include (3) the character of various similarity, (4) the separability property, (5) the support and zero-one law of distribution Pk=PK-1, (6) the Hausdorff dimension and Hausdorff exact measure function.     

1-集压缩型随机算子方程的耦合解

提出了1-集压缩型随机算子方程耦合解的概念,并研究了这类随机算子方程耦合解的存在性.     

一类n维非线性Burgers-BBM方程的Cauchy问题整体解存在性

本文证明了 Burgers-BBM 方程 Cauchy 问题■u_t+udivu-β△u-δ△u_t=f(u,▽u)■|t=0=Φ(x),Φ(x)∈Ⅱ~s(p~■)(s>n/2+1)在 C([0,∞):Ⅱ~s(R~■)(s>n/2+1)中解的存在唯一性,并证明了解在‖·‖_■范数意义下在[0,T]上的稳定性.     

Differences in cardiac myosin light chain LC1 among human,monkey and sheep

Summary The atrial and ventricular myosin light chains of human, monkey and sheep hearts were compared by dodecylsulfate polyacrylamide gel electrophoresis. The atrial light chain 2 and ventricular light chain 2 are similar among these mammals. However, the atrial light chain 1 of monkey has different electrophoretic mobility from those of human and sheep. The monkey ventricular light chain 1 has same mobility as that of sheep but different from that of human.Acknowledgments. This work was supported by MRC of Canada No. MA-8559. Dr G. Jackowski is a scholar of the Medical Research Council of Canada, and is the author to whom all correspondence should be addressed.     

The conduction of the cardiac impulse 1951–1986

Summary The study of the propagation of the cardiac impulse during the last 35 years is reviewed with special attention to the contributions of Silvio Weidmann and his colleagues. Special emphasis is placed on the need to prove that the cardiac impulse is transmitted electrically, even when it is conducted under very abnormal conditions.