Ramsey数R(K_3,K_q-e)

利用一种系统地构造循环着色的算法,借助计算机证明了Ｒａｍｓｅｙ数Ｒ（Ｋ３,Ｋｑ－ｅ）的下述新下界：Ｒ（Ｋ３,Ｋ１１－ｅ）≥４２,Ｒ（Ｋ３,Ｋ１３－ｅ）≥５４,Ｒ（Ｋ３,Ｋ１４－ｅ）≥５９,Ｒ（Ｋ３,Ｋ１５－ｅ）≥６９。     

关于两类拉姆赛数的上界

定义了关于ｍ阶（０,１）方阵的一类拉姆赛数ａ（ｍ）关于ｍ＊ｍ棋盘的ｎ着色的一类拉姆赛数β（ｎ）,并且各给出了它们的一个上界。     

New lower bounds of classical Ramsey numbersR(6, 12),R(6, 14) andR(6, 15)

Three new cyclic graphs are constructed by using a computer, and the lower bounds of three Ramsey numbers obtained: R(6,12)≥224, R(6,14)≥258,R(6,15)≥338, which fill in three blanks in the table of bounds of Ramsey numbers.     

线性谐振子势的相对论效应 Ⅱ: Dirac方程

本文研究了具有线性谐振子型势的Ｄｉｒａｃ方程的束缚态,给出了束缚态存在的条件是标量势大于等于矢量势,在标量势等于矢量势的条件下,给出了Ｄｉｒａｃ方程精确的能谱方程和四分量波函数。对标量势,利用微扰理论给出了能级的近似计算公式,讨论了基态能量的变化特点．     

Induction of vanadium accumulation and nuclear sequestration causing cell suicide in human Chang liver cells

Very little is known about the modulation of vanadium accumulation in cells, although this ultratrace element has long been seen as an essential nutrient in lower life forms, but not necessarily in humans where factors modulating cellular uptake of vanadium seem unclear. Using nuclear microscopy, which is capable of the direct evaluation of free and bound (total) elemental concentrations of single cells we show here that an NH₄Cl acidification prepulse causes distinctive accumulation of vanadium (free and bound) in human Chang liver cells, concentrating particularly in the nucleus. Vanadium loaded with acidification but leaked away with realkalinization, suggests proton-dependent loading. Vanadyl(4), the oxidative state of intracellular vanadium ions, is known to be a potent source of hydroxyl free radicals (OH^.). The high oxidative state of nuclei after induction of vanadyl(4) loading was shown by the redox indicator methylene blue, suggesting direct oxidative damage to nuclear DNA. Flow cytometric evaluation of cell cycle phase-specific DNA composition showed degradation of both 2N and 4N DNA phases in G₁, S and G₂/M cell cycle profiles to a solitary 1N DNA peak, in a dose-dependent manner, effective from micromolar vanadyl(4) levels. This trend was reproduced with microccocal nuclease digestion in a time response, supporting the notion of DNA fragmentation effects. Several other approaches confirmed fragmentation occurring in virtually all cells after 4 mM V(4) loading. Ultrastructural profiles showed various stages of autophagic autodigestion and well defined plasma membrane outlines, consistent with programmed cell death but not with necrotic cell death. Direct intranuclear oxidative damage seemed associated with the induction of mass suicide in these human Chang liver cells following vanadium loading and nuclear sequestration.     

求解边界约束最优控制问题的神经网络

提出了一种求解控制变量含有边界约束最优控制问题的神经网络模型(COCNN).该模型将控制系统动态方程的等式约束隐含于神经网络COCNN结构中,克服了动态方程约束所带来的求解优化问题的困难;仅将控制系统的控制变量选为COCNN的状态变量,从而降低了神经网络的维数;利用饱和特性处理边界约束,可以求得最优控制问题的精确最优解;该COCNN无论是在硬件实现,还是在用数字计算机进行软件仿真方面,都特别适合于并行处理,可显著提高问题的求解速度,具有广阔的应用前景。     

图的点线荫度

图G的顶点集V(G)划分为一些子集,使得每个子集的导出子图是0线森林(即每个分支是路)的最小子集数叫图G的点线荫度,记为v|a(G).Poh K S证明了任何平面图的点线荫度最多是3.Matsumato M给出了图的点线荫度的上界,即v|a(G)≤[△(G)/2].这里△(G)是G的最大度.本文给出了完全n部图的点线荫度计算公式,同时也给出了任意图的点线荫度的精确上下界．     

s域SISO系统概率鲁棒设计新方法

通过引入随机向量截尾分布描述系统不确定性，并对优化性能指标进行概率加权，提出了一种新的鲁棒控制器设计方法。所得结果保守性低，兼顾了鲁棒稳定性和鲁棒性能，且控制器性能在标称情况和最坏情况之间得到概率折衷，实现了整个参数平面的一体化设计。仿真结果表明该方法的有效性。     

关于除数函数的一个结果

证明：定理若α１，…，α是γ个不同的整数；且有：其中Ｋｒ＝ｋ１＋…＋ｋｒ－ｒ，式中隐含的常数仅与δ，γ，ｋ１，…ｋｒ有关。     

小Sidon数上界初探

给出一种新的计算小Sidon数F(k)的准确值或上界的算法,并获得6个Sidon数的新上界:F(15)≤159,F(16)≤191,F(17)≤221,F(18)≤252,F(19)≤298,F(20)≤341.