L-拓扑空间中的正则分离性

本文在L-拓扑空间中引进新的正则分离性概念,给出新正则空间的各种特征性质。证明了新正则分离性是遗传的、可乘的、拓扑不变和L-好的推广,也讨论了新正则与正则及N-正则的关系。     

关于部分K值逻辑中正则可离函数集的极大封闭集之最小覆盖判定的一些结果

根据部分多值逻辑完备性理论，证明了当m=2时，若正则可离关系G2=G2({1，2})∪G2之关系图仅是一个回路，则T(G2)不是Pk^*的最小覆盖成员。     

关于wiener过程增量的某些结果

一、引言 设w(t)是标准Wiener过程,Csrg及Révész在[1]中证明了如下定理:定理A.设a_T(T≥0是T的单调非降函数,如果满足:(i)0相似文献   

超日冕距离矩阵谱的刻画技术（英文）

图的拓扑结构在化学分子结构中有重要的意义,并且图的各种矩阵都蕴含了图的拓扑结构信息.在本文中,我们根据距离谱的定义以及四类图形的构造特点,对四类双日冕图进行了距离谱的刻画,通过数学归纳法得到对应的距离矩阵.在此基础上,本文构建了分块矩阵(超日冕距离矩阵),根据矩阵特征值的唯一性,对超日冕距离矩阵进行特征值以及特征向量的求解,并验证了结论准确性及可靠性.进一步,当G为完全图且G1, G2为正则图时,研究了四类特殊的双日冕图G~((S))? {G1, G2},G~((Q))? {G1, G2}, G~((R))? {G1, G2}, G~((T))?{G1, G2}的距离谱.     

紧支对称准正交小波的正则性

介绍了准正交滤波器及其小波,以及正则性的3个命题。运用尺度函数正则性命题分析了长度为2N的准正交小波的正则性,得到正则指标值.对于N=3,4,5,正则指标分别是α3=1.546 4,α4=1.446 4和α5=1.571 0.     

关于T1定理的一个注解

在 T1 定理之后,人们试图在核的正则性不断逼近 H¨ormander 条件的情况下建立新的 T1 定理。 在本文中,我们运用 Daubechies 小波在正则性稍弱的条件下同样建立 T1 定理。     

拟南芥CRY1基因C末端导入甘蓝型油菜的遗传及表达

通过卡那霉素抗性鉴定,对甘蓝型油菜westar转基因后代T2代株系进行了研究.结合PCR检测及序列比对验证,对拟南芥CRY1基因C末端导入甘蓝型油菜后的遗传表现进行了分析,并利用GUS染色和花色素苷积累量的比较,对CRY1基因C末端在转基因油菜中的表达进行了研究.结果表明:转化的外源目的基因多数以嵌合形式,少数以单拷贝和嵌合的混合形式整合到转基因油菜的基因组中;目的基因能稳定地遗传给后代,株系间遗传传递率为62.5%;T2代的遗传行为少数呈现孟德尔遗传,多数呈现非孟德尔遗传现象;拟南芥CRY1基因能在转基因油菜中表达,但也出现了沉默现象.     

求解病态问题的一种新的正则化子与正则化算法

根据紧算子的奇异系统理论,提出了一种新的正则化子,进而建立了一类新的求解病态问题的正则化方法。证明了正则解的收敛性并得到了其最优的渐近收敛阶,数值算例说明文中建立的正则化算法是可行而有效的。     

有关非线性图像配准的正则化(英文)

近年来,非线性图像配准各种方法的数值分析已经十分成熟;但是大多数工作都没有考虑理论上的收敛性分析.本文对非线性图像配准极小问题进行了理论上的分析证明.我们得到了极小问题正则解的存在性、稳定性及收敛性,证明了在正则化算子和正则参数分别满足一定的条件下,极小问题的正则解收敛到我们所关心的问题的解.这一理论上的证明过程及结果将对非线性图像配准的正则化算子的选取提供十分重要的依据.     

同一语言在不同进制下的正则性研究

本文对同一语言在不同进制的表示下正则性的问题进行了研究,证明了当p与q互质的时候,存在这样的语言L,使得L在p进制表示下是正则语言(字母表为{0,1,···,p-1}),但是在q表示下是非正则语言(字母表为{0,1,···,q-1})。而且p与q互质这一条件是必要的。     

不同氯含量氯化聚丙烯的热降解

用ＴＧ－ＤＴＧ－ＤＳＣ法研究了低氯化聚丙烯（Ｃｌ－ＰＰ）在空气、Ｎ２气流中线性升温时的热降解，发现随Ｃｌ％增加，主链脱ＨＣＬ的失重率增大，而主链的降解失重率减小；Ｎ２气中平衡热降解温度ＴＰ１、Ｔ０．１随ＣＬ％的提高而下降，而ＴＰ２、ＴＰ３与其无关；空气中ＴＰ１、ＴＰ２随ＣＬ％的提高而下降，Ｔ０．１、ＴＰ３与其无关。     

正态云模型的重尾性质证明

正态分布和重尾分布在概率研究中具有非常重要的地位,二者具有完全不同的数学形式和物理意义。正态分布的密度函数以指数函数衰减至0,服从正态分布的随机变量,其绝大多数取值在其期望附近,偏离期望很大的取值很少。而服从重尾分布的随机变量,其尾分布函数具有重尾特性,密度函数以幂指数衰减至0。笔者证明了正态云模型是具有均值的重尾分布,是介于正态分布与重尾分布之间的中间状态,正态云模型的参数超熵He是可以实现正态分布向重尾分布转换的桥梁。     

Tetrahedral frameworks TX2 with T–X–T angle = 180°: Rationalization of the structures of MOF-500 and of MIL-100 and MIL-101

It is shown that the TX₂ structures adopted by the giant MOFs MOF-500, MIL-100 and MIL-101 are uniquely determined as a result of the requirement of regular TX₄ tetrahedra, T–X–T angles of 180° and appropriate X–T–T–X dihedral angles.     

The Bueckner work conjugate integral for a permeable crack in piezoelectric materials

Summary The Bueckner work conjugate integral for cracked piezoelectric materials is studied. The analysis is based on the permeable crack model to avoid the unphysically impermeable crack assumption. It is proved that the values of the Bueckner integrals are dependent on the normal electric displacement component on the crack surfaces and the coordinates of the starting point and the end point of the integral contour on the lower and upper crack faces, respectively. This means that, strictly speaking, the Bueckner integral for the permeable crack model is path-dependent unless a special condition is satisfied, i.e., the horizontal coordinates of the starting point and the end points of the integral contour are the same. The present conclusions are quite different from those derived from the impermeable crack model, where the Bueckner integral is strictly path-independent. The universal relation between the Bueckner integral and the J-integral existing in the impermeable crack model is also proved not to be always valid for the present permeable model unless the special integral contour is taken. This implies that the crack electric boundary condition in piezoelectric materials yields some significant influence on the properties of the Bueckner work conjugate integral.     

Simulation of intense particle beams with regularly distributed Gaussian subbeams

Techniques for the simulation of intense particle beams are investigated with respect to the required number of simulation particles. It is shown that for nonchaotic systems it is advantageous if the particles initially are not distributed in a statistical manner but rather arranged in a regular pattern in phase space. This reduces the number of required simulation particles drastically. In the case of such an initially regular arrangement of particles the algorithm which assigns the charges of the particles to the computation mesh becomes of prime importance. The performances of different commonly used algorithms are investigated. The Gaussian assignment algorithm proved far superior to other more commonly used techniques, allowing simulations even at the theoretical limit of 1 particle per cell. Examples for very accurate simulations of beam dynamics with very few particles using an initially regular mesh of particles and Gaussian assignment are given.     

Application of symmetric indirect Trefftz method to free vibration problems in 2D

A symmetric indirect Trefftz method is developed to solve the free vibration problem of a 2D membrane. It is proved that in this approach the spurious eigensolution exists, and an auxiliary matrix is constructed to help extraction of the spurious solution using the generalized singular‐value decomposition. In addition to the spurious eigensolution, this regular formulation suffers from its ill‐posed nature, i.e. the numerical instability. In order to deal with the numerical instability, the Tikhonov's regularization method, in conjunction with the generalized singular‐value decomposition, is suggested. The proposed approach has some merits when compared with other regular boundary element formulations reported so far; namely the capacity of representing eigenmodes and the ability to deal with a multiply connected domain of genus 1. Several numerical examples are demonstrated to show the validity of the current approach. Copyright © 2003 John Wiley & Sons, Ltd.     

Properties of the Duane plot for repairable systems

The Duane plot is a plot of cumulative operating time against the cumulative failure rate on double logarithmic axes. It is often claimed that the power law process, a non‐homogeneous Poisson process with intensity function , implies a linear Duane plot. We show that this implication and its converse are false. Copyright © 2002 John Wiley & Sons, Ltd.     

Interaction of slow electrons with surface: Empty electronic states and inelastic scattering effects

The fine structure of experimental true secondary-electron emission spectra along the normal to a clean W(1 1 0) surface, target (or total) current spectra, and low-energy-electron-transmission spectra along the normal to a clean 2H-MoS₂(0 0 0 1) surface are interpreted theoretically. It is shown that the fine structure of these spectra is mainly due to the electronic structure of unoccupied high-level electronic states (above the vacuum level), which become occupied by electrons entering the solid. In addition, a comparison to existing theoretical and experimental data is given.     

The n = 3 member of the SrCoO(3n − 1)/n series of layered oxygen-defect perovskites

Topotactic oxygen deintercalation from cubic perovskite oxide SrCoO_3 − δ (δ < 0.25) is realized in a controlled way at low temperatures. Annealing in air at 200 < T < 275 °C results in a three-phase region within 0.25 < δ < 0.50. Two of the phases are known previously, namely SrCoO_2.5, a phase with an orthorhombic brownmillerite-type (BM) structure, and SrCoO_2.75 (T1), a phase with a slight tetragonal distortion from cubic symmetry. The third phase (T2) has a strong tetragonal distortion, and appears to be the missing n = 3 member of the SrCoO_{(3n − 1)/n} series. Once the overall oxygen content reaches the value of (3 − δ)_aver = 2.68(1), the T1-to-T2 phase conversion proceeds at constant (3 − δ)_aver. A more pronounced evolution of the c_T2 lattice parameter as compared to the a_T2 parameter implies a layered oxygen-vacancy-ordered structure for T2 with some flexibility for oxygen-content variation, in the style of the BM phase.