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1.
euler数即系的极限本文用两种方法对之给出证明.一、用闭区间套定理证易知对任何,总有.设则为一闭区间套.由闭区间套定理,存在唯一点使得且由所设从;的表达式,即得二、用单调有界定理不等式两边相加得:有下界.又所以调递减.据单调有界定理,存在.证毕.Euler数存在性的证明@孔志宏$铁路继续教育运输基地北京铁路局干部培训中心!北京,030013[1]科学出版社,《数学手册》 P123  相似文献   

2.
重新证明文[10]中几个重要结论并修正文[10]中的定理1(11)和定理2.在此基础上,利用这些重新证明过的结论及修正过的定理可以按照文[10]中引理3,定理4,定理6,定理7,定理10的证明过程原样证明文[10]中的相应结果.因而在文[10]中,除性质11是结合BZ一代数的等价性质(见文[15]),定理1(11)及定理2需要进行修正外,其余结论及证明过程均成立.  相似文献   

3.
吴赛瑛 《数学通讯》2007,(12):30-31
文[1]、文[2]、文[3]及文[4]对一个三角形重心向量性质进行拓广,文[5]证明了文[1]的逆定理也成立,文[6]将以上的重心性质进行了再推广得到了两个定理,我们可以将这两个定理加强为以下两个命题,证明类似文[6]在此不再证明.  相似文献   

4.
关于《一类奇异边值问题的正解》的注记   总被引:3,自引:0,他引:3  
柴国庆 《数学学报》2003,46(6):1087-109
文[4]通过构造反例断言文[1]中定理的必要性证明有误,本文首先指出文[4] 的这个断言不正确,然后对文[4]中定理2.1作了本质性的改进.  相似文献   

5.
文[1]给出了关于抛物线的弦对顶点张直角的一个充要条件,文[2]给出了关于有心圆锥曲线的弦对顶点张直角的充要条件,读后深受启发.经过研究,笔者把文[1]、文[2]中的三个定理进行了推广合并成一个定理,得到二次曲线内接直角三角形斜边过定点的一个统一的结论,并给出一个比较简洁的证明.  相似文献   

6.
积分不等式是微积分学中一类常见而又重要的不等式,其证明方法多种多样.分别用定积分的定义、积分变限函数、积分第一、第二中值定理、微分中值定理等九种方法证明积分不等式∫0^1xf(x)dx≥1/2∫0^1f(x)dx(其中f(x)在[0,1]上连续而且单调递增),借此介绍证明积分不等式的几种常用的方法.  相似文献   

7.
离散时间不完全金融市场中未定权益的定价   总被引:1,自引:0,他引:1  
对一类连续时间不完全市场(其中的股票价格由Brown运动驱动),ElKarouiandQuenez[1]讨论了一般的不可达未定权益的定价问题.本文利用FollmerandKabanov[2]建立的分解定理,证明[1]中关于买方与卖方价格过程的结果与方法适用于一般的离散时间不完全金融市场(定理1).特别,关于买方与卖方价格我们给出另一种合理的解释(定理3).  相似文献   

8.
黄文华 《数学研究》1997,30(4):382-386
D.E.Leach[3]证明了下述定理:证明了一个同胚定理,利用它证明了方x"+g(x)=e(t)的一个2π周期解的存在性和唯一性定理.所证明的定理是上述定理的一个推广.  相似文献   

9.
邵明宪 《数学通讯》2011,(7):47-47,49
对数列连续项积型不等式,文[1]给出了用其成立的一个充分条件证明的方法.笔者探究发现,用单调性证明某些此类不等式更简便.  相似文献   

10.
一点订正     
众所周知:在[a,b]上具有介值性的函数在[a,b]上未必连续.文[1]除举一反例外,还得到了定理:“定理1若函数f(x)在区间[a,b]上有定义,且在[a,b]上具有介值性,则函数f(x)在区间[a,b]上必不存在跳跃间断点.”但这一“定理”不一定成立.请看下例.例1在[0,1]上,分段定义因函数值充满区间[0,1],故函数g(X)具有介值性,但函数是将的线段分别移上移下而得.如图1.照此,不难作出有更多跳跃间断点仍保持介值性的函数.函数是否具有介值性,关键在于:函数值能否填满某个区间,而与函数值的如何分布无关.因此,我们可以仿照狄利克雷…  相似文献   

11.
A refined shell theory is developed for the elastostatics of a moderately thick spherical cap in axisymmetric deformation. This is a two-term asymptotic theory, valid as the dimensionless shell thickness tends to zero.The theory is more accurate than “thin shell” theory, but is still much more tractable than the full three-dimensional theory. A fundamental difficulty encountered in the formulation of shell (and plate) theories is the determination of correct two-dimensional boundary conditions, applicable to the shell solution, from edge data prescribed for the three-dimensional problem. A major contribution of this article is the derivation of such boundary conditions for our refined theory of the spherical cap. These conditions are more difficult to obtain than those already known for the semi-infinite cylindrical shell, since they depend on the cap angle as well as the dimensionless thickness. For the stress boundary value problem, we find that a Saint-Venant-type principle does not apply in the refined theory, although it does hold in thin shell theory. We also obtain correct boundary conditions for pure displacement and mixed boundary data. In these cases, conventional formulations do not generally provide even the first approximation solution correctly. As an illustration of the refined theory, we obtain two-term asymptotic solutions to two problems, (i) a complete spherical shell subjected to a normally directed equatorial line loading and (ii) an unloaded spherical cap rotating about its axis of symmetry.  相似文献   

12.
The mathematical theory of evidence has been introduced by Glenn Shafer in 1976 as a new approach to the representation of uncertainty. This theory can be represented under several distinct but more or less equivalent forms. Probabilistic interpretations of evidence theory have their roots in Arthur Dempster's multivalued mappings of probability spaces. This leads to random set and more generally to random filter models of evidence. In this probabilistic view evidence is seen as more or less probable arguments for certain hypotheses and they can be used to support those hypotheses to certain degrees. These degrees of support are in fact the reliabilities with which the hypotheses can be derived from the evidence. Alternatively, the mathematical theory of evidence can be founded axiomatically on the notion of belief functions or on the allocation of belief masses to subsets of a frame of discernment. These approaches aim to present evidence theory as an extension of probability theory. Evidence theory has been used to represent uncertainty in expert systems, especially in the domain of diagnostics. It can be applied to decision analysis and it gives a new perspective for statistical analysis. Among its further applications are image processing, project planning and scheduling and risk analysis. The computational problems of evidence theory are well understood and even though the problem is complex, efficient methods are available.Research partly supported by Grants No. 21-30186.90 and 21-32660.91 of the Swiss National Foundation for Scientific Research.  相似文献   

13.
In this paper we develop the fundamental elements and results of a new theory of regular functions of one quaternionic variable. The theory we describe follows a classical idea of Cullen, but we use a more geometric formulation to show that it is possible to build a rather complete theory. Our theory allows us to extend some important results for polynomials in the quaternionic variable to the case of power series.  相似文献   

14.
The central purpose of this paper is to illustrate that combining the recently developed theory of random conjugate spaces and the deep theory of Banach spaces can, indeed, solve some difficult measurability problems which occur in the recent study of the Lebesgue (or more general, Orlicz)-Bochner function spaces as well as in a slightly different way in the study of the random functional analysis but for which the measurable selection theorems currently available are not applicable. It is important that this paper provides a new method of studying a large class of the measurability problems, namely first converting the measurability problems to the abstract existence problems in the random metric theory and then combining the random metric theory and the relative theory of classical spaces so that the measurability problems can be eventually solved. The new method is based on the deep development of the random metric theory as well as on the subtle combination of the random metric theory with classical space theory.  相似文献   

15.
A study is made of the relationship between the stress and strain tensors, temperature, time and the material characteristics in the most general case for a complex loading path. The failure and loss of stability of actual structures corresponds to a complex loading path, when the change in the stress tensor components is not proportional to a single parameter. The same applies to the microphenomena of failure, when the destruction of the material is preceded by a complex redistribution of internal stresses and strains. The phenomenological basis of the theory is developed. This makes it possible to solve a number of practical problems more correctly than has so far proved possible. These problems include problems of the buckling of beam sections and shells. The local strains theory is a variant of the theory of plasticity that allows the solution of the complex loading problem and makes it possible to unify the theory of plasticity and the theory of deformation of theonomic materials. The review is based on more than twenty publications dealing with questions relating to the local strains theory.Mekhanika Polimerov, Vol. 1, No. 4, pp. 12–27, 1965  相似文献   

16.
陈鹄汀  苏振旺 《数学研究》1995,28(3):99-102
本文运用现代控制论的原理与方法研究了地区(或县、市)一级财政收支平衡的控制问题。把财政收支平衡的控制问题置于国民经济系统之中,运用最优控制论建立了最优积累率控制模型;进而,从所求得的最优积累率为出发点,讨论了财政收支的平衡控制,并建立了相应的控制模型。  相似文献   

17.
A modal theory for gratings of deep grooves and arbitrary shape is developed. The theory is implemented with an algorithm of recursion reflection-transmission coefficient matrix (RTCM). Several cases of plane wave with arbitrary polarization and arbitrary angle of incidence diffracted from gratings of deep grooves and arbitrary profile are calculated. It is found that this method is more accurate, more stable and faster than others.  相似文献   

18.
A more general mean flow first harmonic theory is derived and some consequences are discussed. The theory is applied to the Bickley jet and tanh mixing layer profiles.  相似文献   

19.
运用博弈论中委托—代理理论对股权—债权条件下风险投资的激励机制进行了系统分析.根据风险投资家提供股权—债权与风险企业家提供股权融资的假设条件构造了一个基本博弈模型,并对模型进行了推广.研究发现:风险企业家的投资不仅有融资功能,而且还可以作为一种信号传递改变风险投资家的投资信念,使之对项目前景更乐观;扩展模型比基本模型更能改善风险企业家的投资行为,使之投入更多资金和给予风险投资家更高激励;此外,扩展模型更能消除股权—债权投资比例的相互替代性.  相似文献   

20.
本文针对多参数变量和多状态变量的离散型有势系统的非线性稳定问题,提出了活化方法,导出了活化势函数和活化平衡方程.活化方法是弹性稳定理论中Liapunov-Schmidt方法的改进和提高,它比通常的摄动方法更加一般化、规范化.活化势函数可变换成标准突变势函数,活化平衡方程可作为分岔方程.本文的研究将促进弹性稳定理论与突变理论和分岔理论的结合.  相似文献   

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