Prediction of the paper path in a laser printer by finite element analysis

A conventional problem of paper handling in a page-printing printer is to design a reliable paper path. Sometimes, this also affects the printing quality. The nonlinear theory of elastica has often been used to model paper deflection shape and to predict the paper path between some guiding rollers. The present paper proposes another method that can solve this problem more efficiently. Considering a piece of paper as a nonlinear beam, finite element analysis with geometric nonlinearity and manipulating the contact gap element between paper and guiding surfaces can be used to simulate the large-deflection behavior of paper. In this paper, the paper path in the vicinity of an OPC (organic photoconductive) drum is investigated with a general purpose finite element package. The effect of the electrostatic force between the OPC drum and the paper is considered, and the deformed shape of the paper for different forces lengths is obtained. According to those results an appropriate paper guide is added for an exact paper path.     

试卷质量的灰色综合评判

李文革．试卷质量的灰色综合评判．数理统计与管理，１９９７，１６（４），４２～４５．本文运用灰色综合评判评价了文［１］中的七套试卷，得到了与文［１］不同的结果，但本文的结果更符合客观实际。     

严格对角占优三对角矩阵逆元素的估计

本文给出了严格对角占优三对角矩阵逆元素的估计式,获得了比文[1]定理更好的结果。即:去掉了文[1]中非负这一限制条件,且使文[1]的定理成为本文定理之特例。     

曲线拐点充分条件证明中的常见错误

文[1]给出了判别曲线拐点的两个充分条件,文[2]给出了一个充分条件,但三个定理的证明都是错误的.同时,文[1]的两个推论也是错误的.本文通过反例分析了其错因,并给出了文[1]中一个拐点充分条件的正确证明.     

A report on the introduction of a multiple choice examination for a first year university engineering mathematics course

The paper is an account of the experience of introducing a multiple choice mathematics examination paper for the first year engineering mathematics course at Nottingham University. The form of the paper is described, as is a system for providing the candidates with feedback on their performance without the publication of the examination paper.     

广义Kannan型压缩条件的注记

本文给出了 [4 ]中的广义Kannan型压缩条件下映象的一个不动点定理 ,说明了 [2 5]中广义Kannan型压缩条件下映象与 [1 ]中Kannan型压缩条件下映象具有一致的不动点存在性 .     

函数的径向基表示

本文是关于函数的径向表示的综述性文章，基于我们对这方面的研究工作的了解，介绍了国际上近年来这方面的主要的有关研究结果以及在一些领域中应用的情况，文后附有主要的参考文献以便感兴趣的读者查阅。     

MORE ABOUT MELLIN TRANSFORM IN WEAK FUNCTIONS AND MUNTS FORMULA

This paper is a further continuation of the paper [1]. In the present paper Mellin transform and Miints formula of weak functions in complex domain will be treated.     

Evolution Problems involving non-stationary Operators between two Banach Spaces II. Ancillary results

This paper is a direct continuation of the first paper in this series[Quaestiones Math. 8 (1985), no. 2,], which deals Kith the evolution problem [B(t)u(t)]' = A(t)u(t), Bu(0) = y. whereas in the first paper existence and uniqueness results were presented, this paper contains the ancillary results formulated in the first paper. These results describe the properties of B(t)-evolutions with non-stationary generating pairs, as well as of the solution operator of [B(t)u(t)]' = Au, Bu(0) = y.

The notation of the first paper is assumed throughout and is used without further note. Citation of results from the first paper is made by equation number. The numbering of this paper follows that of the first paper in sequence.     

凸函数和凹函数的幂平均不等式

文 [1 ]获得了当 α≥ 1时的凸函数的幂平均不等式 (3)、(4 ) [1] .本文指出文 [1 ]中的一个错误 ,并且得到了 α≤ 1时的凹函数的幂平均不等式 .修正和充实了文 [1 ]的定理 .同时讨论了当 α取其它值时不等式的情况 .     

考虑成本因素的税企博弈模型

本在献[1]的基础上,进一步考虑成本因素在更为一般的条件下建立了新的税企博弈模型,得到国家税务机关最优混合策略及其骗税罚款系数公式,并且指出献[1]的结论是本的一个推论。     

On |A|k summability factors

Summary The paper deals with absolute summability factors for infinite series. The main result obtained in this paper generalizes a recent paper of Mazhar.     

一个组合恒等式的推广(Ⅱ)

用母函数方法获得了一个组合恒等式的更一般的形式.借助这一结果,又给出了若干个有趣的组合恒等式.是作者以前的一篇文章的继续.     

渐近稳定性定理的推广

本文讨论了较一般的非线性微分方程组零解的渐近稳定性，推广了文［１］及文［２］的证明方法和其中的一些结果．特别是去掉了Ｌｉａｐｕｎｏｖ函数具有无穷小上界的条件。最后举例说明作者所得的新结果有效且优于前人的有关结果．     

区间多项式的鲁棒稳定性

本文首先给出了一种新的判定多项式稳定的充要条件（引理2.1）.然后,在此基础上,研究了区间多项式的鲁棒稳定性,得到了若干判别区间多项式的充分条件（定理2.2-定理2.3）.由于所得的摄动界完全可由原末被扰动的多项式的系数所决定,这使得本文的方法比现有的结果简单好用.文末的例子说明了本文方法的有效性.     

Capillary hydrodynamics of the deposition of thin films and droplets on heterogeneous,porous substrates

The work presented here deals with recent research on capillary hydrodynamics of thin viscous liquid films and droplets. The process engineering background comes from the industrial process to deposit thin films or droplets on substrates such as polymer foils or paper [1, 2, 3]. During the production of paper, for example, layers of coating color have to be applied onto the raw paper in order to ensure its usability. Ink–jet paper consists of several different functional layers to optimize the paper with regard to printing quality or paper handling. For the printing process by the ink–jet technique, a controlled application of droplets onto the paper and subsequent penetration of the fluid into the paper are crucial for the final quality of the print. The work summarized here considers the application of films or droplets on substrates as well as the flow of liquids inside porous media. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

等变示性式和它的积分公式

在[1]中,我们给出了一个黎曼流形的一般示性式的积分公式.本文我们将推广[1]中的结果,从普通上同调论推广到等变上同调论.     

Josef Meixner: His life and his orthogonal polynomials

This paper starts with a biographical sketch of the life of Josef Meixner. Then his motivations to work on orthogonal polynomials and special functions are reviewed. Meixner’s 1934 paper introducing the Meixner and Meixner–Pollaczek polynomials is discussed in detail. Truksa’s forgotten 1931 paper, which already contains the Meixner polynomials, is mentioned. The paper ends with a survey of the reception of Meixner’s 1934 paper.     

"求线性规划问题可行基的一种方法"的注记

文[2]通过两个反例的计算,认为文[1]所提出的求LP可行基的方法有不妥之处,并对[1]的方法中主要步骤作了修正。本文对[1]的算法中轴心项的选取作进一步说明,对[2]中所提出的反例以[1]中算法进行计算与[2]对比分析,说明[2]中的反例并不成立。     

近似良紧空间的相对可乘性

文[2]江守礼、李进金定义了相对乘积空间，使不同的LF空间可以进行乘积运算．本文利用广义Zadeh型函数讨论近似良紧空间的相对可乘性，使得文[5]和[6]的一些结论是本文的推论．