不完全数据参数估计问题的算法综述与评价

综述了不完全数据参数估计的EM算法、Gibbs抽样和界定折叠法等算法，并分析了这些算法的优缺点．     

具有抑制剂的恒化器竞争模型

在具有抑制剂的恒化器模型中考虑种群的死亡率，得到模型平衡点的存在性和有界性的充分判据。     

关于指数Diophantine方程的1个猜想

设m,r是适合2｜m，2r，r＞1的正整数；Ur，Vr是适合Vr+Ur-1＝（m+-1)r的整数；a,b,c是适合a＝｜Vr｜，b＝｜Ur｜，c＝m2+1的正整数.证明了：如果b≡3(mod 4),b或c是素数，则方程x2+by＝cz仅有正整数解(x，y，z）＝（a，2，r）.     

一维半空间中线性势相对论性方程的束缚态精确解

在标量势大于矢量势的条件下获得了一维半空间中带线性势的Ｋｌｅｉｎ－Ｇｏｒｄｏｎ方程和Ｄｉｒａｃ方程束缚态的精确解,给出了能谱方程和束缚态波函数。     

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。