一种实对称矩阵特征值的求法

运用正交相似变换将实对称矩阵约化为不可约对称三对角矩阵,依不可约对称三对角矩阵特征值的隔离性质,构造出具有分段严格单调性的等价模型,证明在每一单调区间内有且仅有一个根,并采用具有二次收敛的Newton迭代法求解.最后,给出了算法及算例.     

伪压缩型映象迭代逼近的收敛性问题

研究一类伪压缩型映象迭代逼近的收敛性问题，其结果改进和推广了已有结果．     

Electronic properties and stabilities of methoxy-substituted Lindqvist polyoxometalates [Nb2W4019CH3]3- by DFT

The electronic properties and stabilities of five [Nb2W4O18OCH3]3-isomers have been investigated using a density functional theory method.The results show that the isomer with the methoxy group occupying a bridging position between two tungsten atoms(two tungsten atoms in the plane that contains two niobium atoms) in the [Nb2W4O18OCH3]3-framework is the most stable isomer in acetonitrile.The stability of the one-electron-reduced isomers changes little.The most stable one-electron-reduced isomer has the methoxy group occupying a bridging position between niobium atoms in the [Nb2W4O18OCH3]4-framework.The M-Ob(M = Nb,W;b denotes bridging) bond lengths in anions in which the metal atoms are connected by a methoxy group are longer than those in [Nb2W4O19]4-.The highest occupied molecular orbitals(HOMO) in [Nb2W4O19]4-mainly delocalize over the bridging oxygen atoms of two niobium atoms and two tungsten atoms located in the equatorial plane,and the bridging oxygen atoms on the axial surface.The lowest unoccupied molecular orbitals(LUMO) of [Nb2W4O19]4-are mainly concentrated on the tungsten atoms and antibonding oxygen atoms.Methoxy substitution modifies the electronic properties of the [Nb2W4O18OCH3]3-isomers.The HOMOs in the five isomers formally delocalize over the bridging oxygen atoms,which are distant from the surface containing the methoxy group and four metal atoms.The LUMOs delocalize over the d-shells of the four metal atoms that are close to the methoxy group,and the p-orbitals of oxygen.One-electron reduction occurred at the tungsten atoms,not the niobium atoms.     

一类具有LiPschitz条件的非线性算子的迭代过程

在Ｂａｎａｃｈ空间中，研究了带有误差项的Ｉｓｈｉｋａｗａ迭代序列的收敛问题，旧了通常文献中关于空间Ｅ的一致光滑或ｑ－一致光滑的严格要求。改进和推广了近期文献「１－６」中的相关结果。     

带误差项的广义集值变分包含

研究了一类新的广义集值变分包含：０∈Ｎ（ｗ，ｙ）＋Ａ（ｚ，ｕ）在实Ｈｉｌｂｅｒｔ空间，利用极大单调算子的性质，建立了广义集值变分包含和不动点问题的等价性，利用这种等价性，建立了一些摄动迭代算法，并证明了近似解序列强收敛于精确解。     

不连续二阶积分-微分方程初值问题的惟一性

在一般序Banach空间中研究了含导数的不连续二阶积分-微分方程初值问题解的存在惟一性，并给出了解的显式迭代序列和误差估计。     

Growth mechanism of liquid Hg/solid β-HgS metal-semiconductor heterostructures

Density functional theory （DFT） was utilized to simulate the reactions occurred in the mixture solution of cysteine and Hg（II） ions with the ratio 〈 2. Simulation result shows that Hg ions will coordinate to cysteine by the thiol groups with the form of S-Hg2 and S-Hg3; and moreover, the content of free Hg ions can only be reduced by these two forms. OH- plays an important role in the growth of β-HgS, because its nucleophilic substitution reaction supplies plenty of Hg-S-Hg radicals, which will be adsorbed onto the surface of liquid mercury ball and form the precursor of 13-HgS（111） plane. Three valent bonds adsorption of Hg-S-Hg radicals onto the surface of Hg ball has more adsorption energy （-32.768 kcal mol-1） than that of two valent bond adsorption （-20.882 kcal - mol-1）. Hg balls will stop growing after completely covered with Hg-S-Hg radicals and their size will be limited. The growth direction of β-HgS is parallel to the ＂repel- ling＂ force, that is [111] direction in β-HgS lattice. The calculated results are in good agreement with the experimental observations, demonstrating that the DFT method can be taken as a very useful tool to interpret the solution reactions that cannot be solved by conventional methods.     

工业过程稳态优化中的PID型迭代学习控制

给出一种PID型迭代学习算法．对工业过程稳态优化中的动态施行迭代学习控制，加快了动态响应，提高了控制效果．从理论上分析了算法的收敛性，并给出数字仿真结果．     

块AOR,块SOR和块JOR迭代法的收敛性

本文引进块Jacobi迭代矩阵B的优矩阵(?),来研究解线性方程组的块AOR、块SOR和块JOR迭代法的收敛性。即若‖·‖是矩阵的某个相容范数。且‖B_(ij)‖(?)β_(ij),i,j=1,…,m,则令(?)=(β_(ij))。利用(?),我们给出了块AOR(0(?)γ<2/[1+ρ(?)]),0<ω相似文献