INITIAL VALUE TECHNIQUES FOR THE HELMHOLTZ AND MAXWELL EQUATIONS

We study the initial value problem of the Helmholtz equation with spatially variable wave number. We show that it can be stabilized by suppressing the evanescent waves. The stabilized Helmholtz equation can be solved numerically by a marching scheme combined with FFT. The resulting algorithm has complexity n^2 log n on a n x n grid. We demonstrate the efficacy of the method by numerical examples with caustics. For the Maxwell equation the same treatment is possible after reducing it to a second order system. We show how the method can be used for inverse problems arising in acoustic tomography and microwave imaging.     

Discrete-time GI/Geo/1 queue with multiple working vacations

Consider the discrete time GI/Geo/1 queue with working vacations under EAS and LAS schemes. The server takes the original work at the lower rate rather than completely stopping during the vacation period. Using the matrix-geometric solution method, we obtain the steady-state distribution of the number of customers in the system and present the stochastic decomposition property of the queue length. Furthermore, we find and verify the closed property of conditional probability for negative binomial distributions. Using such property, we obtain the specific expression for the steady-state distribution of the waiting time and explain its two conditional stochastic decomposition structures. Finally, two special models are presented.      

Numerical simulation of critical dependences for symmetric two-layered Josephson junctions

Partial critical dependences of the form current-magnetic field in a two-layered symmetric Josephson junction are modeled. A numerical experiment shows that, for the zero interaction coefficient between the layers of the junction, jumps of the critical currents corresponding to different distributions of the magnetic fluxes in the layers may appear on the critical curves. This fact allows a mathematical interpretation of the results of some recent experimental results for two-layered junctions as a consequence of discontinuities of partial critical curves.     

球面稳定同伦中的复合元素α1β1γs的非平凡性

本文证明:当p≥7任意奇素数,3≤s相似文献   

A procedure for measuring the flexibility of single wood-pulp fibres

A way of determining the flexibility of wood-pulp fibres is developed, which involves i) a precise measurement of the topology of single-fibres by using a confocal laser scanning microscope and ii) the measurement of the elastic modulus of the fibres by using a single-fibre fatigue cell. Reported in this paper are the initial results of tests carried out on black spruce fibres, which have been subjected to three different levels of mechanical refining energy, namely ∼1100, 2300, and 3500 kWh/t. It is found that the fibre flexibility rises significantly between the first and second energy levels, but it does not change to the same degree between the second and third ones. The described procedure of measuring the flexibility of fibres may be used to establish the appropriate refiner energy necessary for the production of a specific grade of paper. Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 42, No. 1, pp. 115–128, January–February, 2006.     

Multipliers of convergence in norm of series with respect to multiplicative systems

We prove analogs of the Telyakovskii-Pochuev criteria for multipliers of uniform convergence and of convergence in the integral metric for multiplicative systems with bounded generating sequence.     

代数基本定理的另一证明

在复变函数论中,用了两种不同的方法证明了代数基本定理。文章从另一种角度:用映射的观点证明该定理。     

浅论萨克斯管吹奏中常遇的问题及解决方法

萨克斯管吹奏中常出现音色概念、呼吸、指型、口型等方面的错误，阐述了其解决的方法，同时从理论的角度分析了原因，以帮助吹奏掌握正确、规范的萨克斯管吹奏方法。     

论何心隐的政治思想

自王艮开创泰州学派以来,其学术命脉还是内圣外王之道,何心隐作为该学派的三传弟子,在继承前人的基础上,把泰州学派的思想推向了较高的阶段。他的政治思想就是继孔孟之道,建立以师友为基础的人际关系,在社会实行完全平等的理想主义,这些反映了以何心隐为代表的明代的平民思想家要求改变社会现状,实现大同社会的理想追求。     

应用程序与数据库的接口设计技术

在管理系统开发过程中，应用程序的编写和数据库的设计都是比较容易实现的，而应用程序与数据库的接口设计却难于实现且容易出错。文章就这一问题论述了几种常见的编程语言编写的应用程序与数据库间的接口设计方法与技巧。