类氢离子电子碰撞激发截面实用定标公式

本文给出了一套计算类氢离子电子碰撞激发截面和速率系数的实用参数,用于计算nl→n'l'跃迁数据,n=1,2,…,4,n'=2,3,…,8。适用范围:3 ≤ Z ≤ 74,n'≤5时,x≥2,n'>5时,x≥20。误差30%左右。     

多点边值问题的插值矩阵法及误差分析

插值矩阵法是求解多点边值问题的数值法。本文给出的该法的误差分析,论证了插值矩阵法解得的y(x),y'(x),…,y^(m)(x)有相同的精度,并对二阶方程,给出该法的稳定性证明和收敛阶。     

中性D介子混合和强作用相角差的唯象研究

利用在B工厂中测量的混合参数y′,y_CP和x,在D⁰→Kπ衰变模式里面讨论了混合参数对强作用相角差的约束.在ψ（3770）峰值上,利用CP标记技巧,讨论了在BES-Ⅲ上强作用相角差的测量及可能达到的精度,混合参数y的测量及可能达到的精度.最后讨论了在BES-Ⅲ上混合率R_M的测量及可能达到的精度. 关键词： 强作用相角差 混合参数 BES-Ⅲ     

部分相干径向偏振光束传输中相干性研究

根据广义惠更斯理论及相干偏振统一理论, 研究部分相干径向偏振光束在自由空间中传输时, 不同参考点处复相干度随传输距离的变化规律. 研究表明, 部分相干径向偏振光束在自由空间中传输, 不同参考点处, 复相干度模值随距离的变化规律有所差别. 当参考点位于原点时, 随着传输距离增大, μ_xx模值及μ_xy模值分布形式不变, 分布范围增大; 当参考点位于x轴上时, μ_xx模值由单峰值向三峰两谷对称形式演化, μ_xy模值由单侧两峰向四峰四谷对称形式演化, 完成演化所需传输距离与参考点距离x轴中心的远近有关, 参考点距离x轴中心越近, 完成演化所需的传输距离越短; 当参考点位于y轴时, 随着距离增大, μ_xx模值分布形式不变, 分布范围增大, μ_xy模值由上侧两峰向四峰四谷对称形式演化, 演化所需传输距离与参考点距y轴中心远近有关, 参考点距y轴中心越近, 完成演化所需的传输距离越短; 当参考点位于其他位置时(非特殊位置), μ_xx模值及μ_xy 模值分布规律, 遵从各自参考点在x轴, y轴上的分布规律的结合即参考点位于其他位置时, μ_xx模值及μ_xy模值分别随距离变化逐渐演化成三峰结构、四峰结构.     

精确提取一维互易有限周期性结构色散特性的宏元胞法

提出了一种可精确提取一维互易有限周期性结构色散特性的宏元胞法. 将多个周期性元胞组合构成单个“宏元胞”, 以严格考量元胞间的互耦效应, 通过Bloch分析分别计算出正向激励和反向激励时Bloch 波的本征传输因子ξ^N和1/ξ^N, 对ξ^N取复对数操作即可解出一维有限周期性结构的衰减常数α, 而复对数函数的多值性使得相移常数β存在多整数分支的选择问题. 通过与解卷绕法获得的β近似值相比较,选择出合理的整数分支, 可精确计算出β. 与传统的本征模式法、解卷绕法及单元胞法相比,宏元胞法对元胞间的耦合强度不作要求, 计算更加精确快速, 可作为刻画一维互易有限周期性结构色散和Bloch阻抗特性的有力工具. 关键词： 宏元胞法 Bloch分析 色散特性     

中红外高双折射高非线性宽带正常色散As2 S3光子晶体光纤

设计了一种中红外As₂S₃光子晶体光纤,利用多极法研究了这种光纤的双折射、色散和非线性特性.数值研究发现,该光纤在中红外波段λ = 3.625 μm处双折射B高达0.098;其x偏振方向的非线性系数γ_x达到了1.69 m^-1 ·W^-1, y偏振方向的非线性系数γ_y达到了0.78 m^{- 关键词： 光子晶体光纤 中红外波段 双折射 非线性}     

W22[a,b]空间中的最佳Hermite插值算子

本文介绍具有再生核的函数Hilbere空间W₂²给出了W₂²空间再生核的有限表达式,利用它构造出最佳Hilbere插值逼近算子(H_2nu)(x)的真体表达式,当节点系无限加密时,能够保证(H_2nu)(x)一致收敛于u(x),(H_2nu)(y)一致收敛于u'(x),且每增加一个节点,误差在Sobolev范数意义下单调下降。     

奇摄动拟线性弱耦合系统解的估计

本文研究奇摄动拟线性系统边值问题#br#εY"=F(t,y,ε)Y'+g(t,y,ε),(0≤t < 1)#br#Y(0,ε)=A(ε),Y(1,ε)=B(ε)#br#其中,Y,g,A,B都是n维向量,F(t,Y,ε)是n×n阶对角短阵,Y',Y"是关于变量t的导数。     

构造非线性发展方程的无穷序列复合型类孤子新解

为了构造非线性发展方程的无穷序列复合型类孤子新解, 进一步研究了G'(ξ)/G(ξ) 展开法. 首先, 给出一种函数变换, 把常系数二阶齐次线性常微分方程的求解问题转化为一元二次方程和Riccati方程的求解问题. 然后, 利用Riccati方程解的非线性叠加公式, 获得了常系数二阶齐次线性常微分方程的无穷序列复合型新解. 在此基础上, 借助符号计算系统Mathematica, 构造了改进的(2+1)维色散水波系统和(2+1)维色散长波方程的无穷序列复合型类孤子新精确解. 关键词： G'(ξ)/G(ξ)展开法')" href="#">G'(ξ)/G(ξ)展开法 非线性叠加公式 非线性发展方程 复合型类孤子新解     

不同晶体取向下纳米压痕的多尺度模拟

采用准连续介质多尺度方法模拟面心立方金属铝单晶薄膜的纳米压痕变形过程.对薄膜分别采用三种不同的晶体取向(分别为x［1 1 1］,y［1 1 0］,z［1 1 2］; x［1 1 2］,y［1 1 1］,z［1 1 0］;x［1 1 0］,y［0 0 1］,x［1 1 0］),得到载荷-位移响应曲线.加载过程中,对晶体内部变形比较剧烈的部分画出原子图,并从微观角度分析产生剧烈变形的原 关键词： 纳米压痕 准连续介质方法 晶体取向 位错成核     

The angular intensity correlation functions C(1) and C(10) for the scattering of light from randomly rough dielectric and metal surfaces

We study the statistical properties of the scattering matrix S(q|k) for the problem of the scattering of light of frequency ω from a randomly rough one-dimensional surface, defined by the equation x₃=ζ(x₁), where the surface profile function ζ(x₁) constitutes a zero-mean, stationary, Gaussian random process. This is done by studying the effects of S(q|k) on the angular intensity correlation function C(q,k|q',k')=〈I(q|k)I(q'|k')〉-〈I(q|k)〉〈I(q'|k')〉, where the intensity I(q|k) is defined in terms of S(q|k) by I(q|k)=L^-1₁(ω/c)|S(q|k)|², with L₁ the length of the x₁ axis covered by the random surface. We focus our attention on the C⁽¹⁾ and C⁽¹⁰⁾ correlation functions, which are the contributions to C(q,k|q',k') proportional to δ(q-k-q'+k') and δ(q-k+q'-k'), respectively. The existence of both of these correlation functions is consistent with the amplitude of the scattered field obeying complex Gaussian statistics in the limit of a long surface and in the presence of weak surface roughness. We show that the deviation of the statistics of the scattering matrix from complex circular Gaussian statistics and the C⁽¹⁰⁾ correlation function are determined by exactly the same statistical moment of S(q|k). As the random surface becomes rougher, the amplitude of the scattered field no longer obeys complex Gaussian statistics but obeys complex circular Gaussian statistics instead. In this case the C⁽¹⁰⁾ correlation function should therefore vanish. This result is confirmed by numerical simulation calculations.     

A continuum model of a solid with a free surface: I. Normal mode analysis of the model

A complete analysis is made of the normal modes of an isotropic continuum model of a solid which occupies the region (0, 0, 0) < (x, y, z) < (X, Y, Z), the limit (X, Y, Z) → (∞,∞,∞) being taken. The surface z = 0 is a free surface and that z = Z is fixed; cyclic boundary conditions are used in the x and y directions. The modal displacements (vectors), modal frequencies (as a function of the wave-vectors), and wave-vector-densities are obtained for all types of normal modes; the work is a modification and extension of that of earlier workers.     

Deformation measurement using high resolution Moiré photography

By installing a slotted mask inside the lens of a 35 mm camera the response can be tuned to resolve 300 lines/mm. The camera is used to record changes in fine grid patterns applied to engineering structures and by analysing the processed negatives in a spatial filtering system, moiré fringe maps are generated representing in detail the separate x and y displacements that have occured. Measurements have been obtained from materials ranging from concrete to soft plastics and a variety of patterns is described for treating most surfaces.     

Jacobi矩阵特征值反问题

研究如下一类Jacobi矩阵特征值反问题:问题IEP:给定两个互异实数λ,μ(λ<μ)和两个n维非零实向量x,y,求n阶Jacobi矩阵J,使得(λ,x),(μ,y)分别恰是J的第i,j(i≠j)个特征对。还分析了Jacobi矩阵的特征性质,给出了一个特征对恰是Jacobi矩阵J的第i个特征对的充分必要条件,由此导出了问题IEP有解的充分必要条件。     

Preparation, characterization and oxide ion conductivity in U-substituted Bi4V2O11

A Bi₂V_{1 − x − y}U_xBi_yO_{5.5 + 0.5x − y} solid solution derived from Bi₄V₂O₁₁ has been prepared and characterized with x up to 0.125 for y = 0. Partial substitution of U⁶⁺ for V⁵⁺ in Bi₄V₂O₁₁ leads to the stabilization at room temperature of the high-oxide ion conducting γ-phase, in contrast with other M⁶⁺ dopants which stabilize the β-phase. The lower conductivity in U substituted system compared with BICUVOX.10 is attributed to its higher activation energy. Conductivity values and activation energies of the U substituted phases compare well with Bi₂UO₆.     

Lithium insertion to ReO3-type metastable phase in the Nb2O5–WO3 system

Lithium insertion to distorted ReO₃-type metastable solid solution Nb_xW_1−xO_3−x/2 (0≤x<0.25) has been studied by chemical and electrochemical methods. In the course of lithium insertion into tetragonal compounds, transition to a cubic phase was found to occur in the region where values of y (in Li_yNb_xW_1−xO_3−x/2) fall between 0.2 and 0.3, and the phase transition was found to depend on the conditions of the reaction. Changes in OCV and lattice parameters in tetragonal region (y<0.2) were discussed from the viewpoint of the ordering of lithium ions. Also, the component diffusion coefficient of lithium in tetragonal compounds Li_0.1Nb_xW_1−xO_3−x/2 (0≤x≤0.23) was found to increase with niobium content when x≤0.10, and to saturate at 4×10⁻⁹ cm²/s.     

Scaling limit of deeply virtual compton scattering

I outline a perturbative QCD approach to the analysis of the deeply virtual Compton scattering process γ^*p → γp′ in the limit of vanishing momentum transfer t = (p′ − p)². The DVCS amplitude in this limit exhibits a scaling behavior described by two-argument distributions F(x,y) which specify the fractions of the initial momentum p and the momentum transfer r ≡ p′ − p carried by the constituents of the nucleon. The kernel R(x,y;ξ,η) governing the evolution of the non-forward distributions F(x,y) has a remarkable property: it produces the GLAPD evolution kernel P(x/ξ) when integrated over y and reduces to the Brodsky-Lepage evolution kernel V(y,η) after the x-integration. This property is used to construct the solution of the one-loop evolution equation for the flavor non-singlet part of the non-forward quark distribution.