二维抛物型方程简单实用的显格式

提出了一个解二维抛的型方程初边值问题的简单实用的显格式，证明了其截断误差阶是Ｏ，稳定性条件是α＋β≠１／２且ｍａｘ｛α，β｝≤１／４，其中，α＝α．Δｔ／Δｘ＾２．β＝α．Δｔ／Δｙ＾２。     

Design of Hamming Code Checker Using Titanium-Diffused Lithium Niobate-Based Waveguide

ABSTRACT

This work presents an electro-optic effect-based design for the widely used Hamming code for checking single bit errors in the received data. The structure is based on Mach-Zehnder Interferometer, designed using Titanium-diffused Lithium Niobate-based waveguides. The proposed device has been successfully tested using the beam propagation method. For a received 7-bit code, the three simultaneously generated check bits are combined to check the error position. Critical performance parameters like extinction ratio (24.39dB), contrast ratio (25.711dB), insertion loss (0.041dB), and amplitude modulation (0.079dB) calculated for the overall device are within acceptable limits for the feasibility of the device.     

Characterization of polynomials and divided difference

For distinct points x₁,x₂,…,x_n in ℛ (the reals), letϕ[x₁, x₂,…,x_n] denote the divided difference ofϕ. In this paper, we determine the general solutionϕ,g: ℛ → ℛ of the functional equationϕ[x₁,x₂,…,x_n] =g(x₁,+ x₂ + … + x_n) for distinct x₁,x₂,…, x_n in ℛ without any regularity assumptions on the unknown functions.     

临界群与二阶差分方程解的多重性

研究了一类二阶非线性差分方程两点边值问题解的多重性.当该问题的非线性项在无穷远点具有特殊的渐近线性性质时,利用变分方法,结合临界群与Morse理论,同时考虑正、负能量泛函的临界点,不论该问题是否发生共振,均证明了它至少存在两个非零解.     

一类Pointaré差分方程解的渐近性质

以二阶的情形讨论了Ｐｏｉｎｃａｒ差分方程ｙ（ｎ＋ｍ）十（ａ１＋ｐ１（ｍ））ｙ（ｎ＋ｍ－１）＋…＋（ａｎ＋ｐｎ（ｍ））ｙ（ｍ）＝０当其常系数部分ｘ（ｎ＋ｍ）＋ａ１ｘ（ｎ＋ｍ－１）＋…＋ａｎｘ（ｍ）＝０的特征方程有相同的根时，解的渐近性质．通过不动点方法给出了Ｐｏｉｎｃａｒ差分方程的解渐近于其常系数方程解的条件，并给出了渐近式高阶项的估计．     

LONG-TIME CONVERGENCE OF GENERALIZED DIFFERENCE METHOD FOR NAVIER-STOKES EQUATIONS

1　IntroductionIn this paper,we firstprovide a generalized difference method for the two-dimension-al Navier-Stokes equations by combining the ideas of staggered scheme[6] and generalizedupwind scheme [4 ] in space,and by backward Euler time-stepping.Then we apply theabstractframework of[7] to prove its long-time convergence.The outline of this paper is as follows:In§ 2 we state the generalized differencemethod.In§ 3 we provide some lemmas.In§ 4 we study the one-sided Lipschitz condi-tio…     

Oscillatory and Asymptotic Behavior for Second Order Quasilinear Difference Equations

1 IntroductionConsider the second order quasilinear difference equationA(g(Ay.--l)) + f(n,y.) = 0, for n E N(no), (l'l)where A is defined by Ay. = Vn+1--yn, n E N(no) = {no, no + 1,'' }, nO E N = {l, 2,'. }.The following hold throughout the paPer:(H0) (i) g: R-R is a continuous increasing fUnction with propertiessgng(y) = sgny) g(R) = R;(il) f: N(no) x R--+ R is continuous as a function of y E R;(iii) yf(n,y) > 0 for n E N and y / 0.By a solution of the equation (1.l) we mean a non…     

非线性时滞差分方程的全局吸引性

得到了具有多重时滞非线性差分方程x(n 1)-x(n) ∑i=1^k pi(n)fi(x(gi(n)))=0,n=0,1,2,…的每个解趋于零的充分条件。     

带导数边界条件的线性双曲方程的一个二阶L∞收敛格式

In this paper, a difference scheme is derived for the one dimensionallinear hyperbolic differential equation with derivative boundary conditions by themethod of reduction of order. It is proved that the scheme is unconditionally sta-ble, uniquely solvable and second order convergent in L∞ norm. Two numericalexamples are presented.     

双原子正方晶格光子晶体边界模式的光传输特性

利用平面波展开法,发现双原子正方晶格光子晶体中ΓM方向边界面存在着快慢两类边界模式,并且通过计算色散关系和电场分布研究了边界参量对这两类边界模式传输特性的影响.依据两种模式的色散关系,计算了群指数和群速度色散参量,结果表明边界参量的变化对第一类边界模式传输特性的影响较小,该模式的平均群指数始终维持在5.0左右;第二类边界模式与第一类模式明显不同,边界参量的变化能够有效地影响到这种模式的传输特性,该模式的最大平均群指数可达178左右.利用时域有限差分法记录了不同时刻电场强度在边界附近的分布及监测点处的电场幅度变化情况,结果表明,两类模式都能够被限制在边界附近并向前传播,时域有限差分法得到的群速度与平面波展开法的结果完全吻合.