速度一压力的双线性一常数有限元

本文把内部罚函数方法应用于Stokes问题,讨论了低阶实用的双线性、常数有限元,得到误差在H'模和L'模的最优阶收敛.     

SOLUTIONS OF MAGNETOHYDRODYNAMICS EQUATIONS-THE THEORY OF FUNCTIONS OF A COMPLEX VARIABLE UNDER DIRAC-PAULI REPRESENTATION AND ITS APPLICATION IN FLUID DYNAMICS (Ⅳ)

This work is the continuation of the discussion of Refs.[1 3].(A) We turn the Magnetohydrodynamics equaitons of isentropic compresible andnon-dissipative magneto-flow into the form of the ideal hydrodynamics equations in thispaper;we can obtain the general Chaplygin equation from Ref.[3],and the generalsduction of this equation.(B)We apply the theory of functions of a complex rariable under Dirac-paulirepresentation,turn the general Magnetohydrodyamics equations of incompressiblemageto-flow into two nonlinear equaitons for flow function and"magneto-flow function",and obtain the exact stable solution of incompressible magnetohydrodynamics equationsunder the condition of stable magnetic field(i.e.under conditon of equality for kinematicalviscid coefficient or viscid diffusion coefficient with magnetic diffusion coefficient).     

Solution of spline function of elastic plates

In this paper.from four and three-order differential equations defined by cubic andquadratic splines of generaized beam.The beam functions with many boundary conditionsand under various loads are reduced.The approximate solution of deformation surface andstress of elastic thin plate is very accurate.     

时变信道序列检测的概率收敛定理和检测截止所引起的误码增皿

时变信道中的信号色散现象是使数字通信系统性能显著下降的主要因素,特别是多径展宽(即所谓的符号间干扰)的增大将强烈地限制通信速率的提高.因此,对信道色散的测量和寻求各种改善数字通信质量的途径的研究,历来为通信系统的设计者所关注,一直没有中断.为了寻找克服多径效应对数字通信影响的新的途径,文献[1]、[2]依据多径传输和时间分集接收技术之间的相似特性,对广大平稳随机时变信道上使用最大似然序列检测技术的问题进行了研究,得到了若干很有意义的结果;并提出了“在采用序列检测技术后,符号间的干扰越严重,其抗衰落的性能反而越好,当符号间干扰无限严重时,时变信道将被改造成恒参信道”这个在逐比特检测情况下认为是不可思议的结论.     

An approximate solution considering flow inertia between spherical surfaces

In this paper, the analytical expressions of the pressure distribution, velocity distribution and discharge of the flow between spherical surfaces are found by using the method of iterative approximate solution when the inertia terms of Navier-Stokes equations in spherical coordinates are taken into consideration. Furthermore, using these expressions, we can directly obtain the corresponding analytical expressions of the laminar radial flow between parallel disks, which are fully identical with corresponding results presented by refs. [3,4].     

一种减小改装电表实验误差的有效方法

在电表改装实验中,由于电阻计算值与标称值不一致,从而引起实验结果存在一定的误差。本文所介绍的方法能有效减小该因素产生的实验误差。     

Metrological estimation of sampling and sample preparation procedures as applied to analytical testing of technogenic origin raw material containing recoverable precious metal

 Different schemes of analytical testing including the sampling, sample preparation and sample analysis operations are considered as applied to a lot of raw material containing recoverable precious metal. The errors resulting from the step-by-step operations of the analytical testing are estimated. Sampling and sample preparation operations are found to be significant contributors to the total error of determination of the percentage and /or weight of a precious metal of interest in a lot. Some ways to diminish both the sampling error and the total error of the analytical testing procedure are recommended. Received: 28 December 1998 · Accepted: 22 February 1999     

关于“解一维热传导方程的高精度的隐式差分格式”一文的评注

本文指出了文[1]中存在的几个问题。     

NA序列经验过程振动模的收敛速度

建立了NA序列经验过程振动模的强收敛速度,类似于独立同分布序列．并把它应用到线性模型,考虑了误差分布的估计．     

Error Bounds for Nonnegative Dynamic Models

The extension of Markov reward models to dynamic models with nonnegative matrices is motivated by practical applications, such as economic input–output, employment, or population models. This paper studies the generalization of error bound theorems for Markov reward structures to dynamic reward structures with arbitrary nonnegative matrices. Both irreducible and reducible matrices are covered. In addition, results for the stochastic case are unified and extended. First, generalized expressions are derived for average reward functions. The special normalization case is distinguished and is shown to be transformable into the stochastic case. Its interpretation is of interest in itself. Next, error bound results are studied. Under a general normalization condition, it is shown that the results for the stochastic case can be extended. Both the average case and the transient case are included. A random walk-type example is included to illustrate the results.