高动态条件下伪随机码信号相关函数研究

在扩频接收机中,受发射机和接收机之间的相对运动和时钟频率不稳定等动态因素的影响,接收伪码和本地伪码之间会存在一定的频移。本文推导并验证了频移条件下的伪随机码信号相关函数及其均值公式,在此基础上分析了频移对伪随机码信号相关函数的影响,包括主瓣展宽、峰值移位和损耗等现象。本文的结论为高动态接收机伪码同步技术提供了理论基础。     

硼化镧薄膜的发射特性研究

LaB6阴极凭借其优良的发射特性已广泛应用于各种大电流密度的电子源，但是硼化镧薄膜的制备方法以及其发射特性还未得到深入的研究，本文对在Ta金属基底材料上使用电子束蒸发法得到的硼化镧薄膜表面型貌使用扫描电子显微镜进行了观测，使用XPS紫外光电子能谱仪测量了其原子比，薄膜显示出良好的发射特性，利用热发射测量逸出功，利用Richardson直线法计算得到薄膜材料的逸出功为2．64eV。     

Calculation of electron wave functions and refractive index of Ne

The radial wave functions of inner electron shell and outer electron shell of a Ne atom were obtained by the approximate analytical method and tested by calculating the ground state energy of the Ne atom. The equivalent volume of electron cloud and the refractive index of Ne were calculated. The calculated refractive index agrees well with the experimental result. Relationship between the refractive index and the wave function of Ne was discovered. Supported by the New Star Program of Beijing Science and Technology, China (Grant No. 952870400), the Beijing Municipal Commission of Education, and the Excellent Young Teachers Program of Ministry of Education, China     

可能性理论的推广方法及合理性研究

本文通过引入二维可能性分布函数的概念，将可能性测度推广到二维的情形。并给出了二维可能性测度的一些重要性质。文中还重点证明了该推广方法的合理性。     

Entire functions, analytic continuation, and the fractional parts of a linear function

The main result of the paper is as follows.Theorem. Suppose that G(z) is an entire function satisfying the following conditions: 1) the Taylor coefficients of the function G(z) are nonnegative: 2) for some fixed C>0 and A>0 and for |z|>R₀, the following inequality holds:

The nonexistence of positive solutions to some elliptic equations

The main result of the paper is the nonexistence of integer positive solutions in wide classes of quasilinear elliptic equations whose model examples are equations of the form {

Representation of the space of polyanalytic functions as a direct sum of orthogonal subspaces. Application to rational approximations

Suppose thatD={z:|z|<1}, L ₂ (D) is the space of functions square-integrable over area inD,A _k (D) is the set of allk-analytic functions inD, (A ₁ (D)=A(D) is the set of all analytic functions inD),A _k L ₂ (D)=L ₂ (D)∩A _k (D),A ₁ L ₂ (D)=AL ₂ (D),

复Clifford分析中的双曲调和函数

将多元复分析中一种复偏微分方程组的解与复Clifford分析中双曲调和函数联系起来,并研究了双曲调和函数的几个性质。     

Integrability of superharmonic functions, uniform domains, and Hölder domains

Let denote the space of all positive superharmonic functions on a domain . Lindqvist showed that is a bounded subset of . Using this, we give a characterization of finitely connected -dimensional uniform domains and remarks on Hölder domains.

     

Simple bounds for closed queueing networks

Consider a closed Jackson type network in which each queue has a single exponential server. Assume that N customers are moving among k queues. We establish simple closed form bounds on the network throughput (both lower and upper), which are sharper than those that are currently available. Numerical evaluation indicates that the improvements are significant.