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1.
张永正  南基洙 《数学进展》1998,27(3):240-246
设L=W或S,F是特征数大于2的域,本文证明F上的有限维单李超代数L(m,n,t)的自然滤过是不变的,进而得出L(m,n,t)与L(m′,n′,t′)同构的充要条件是m=m′,n=n′和ti=τ(t′i),i=1,2,...,m这里τ是(1,2,...,m)的一个置换。  相似文献   

2.
设L=W或S,F是特征数大于2的域.本文证明了F上的有限维单李超代数L(m,n,t)的自然滤过是不变的.进而得出了L(m,n,t)与L(m′,n′,t′)同构的充要条件是m=m′,n=n′和ti=τ(t′i),i=1,2,…,m,这里τ是{1,2,…,m}的一个置换.  相似文献   

3.
设{αk}∞k=-∞为正数缺项序列,满足infkαk+1/dk=α>1,Ω(y′)为Besov空间B0,11(Sn-1)上的函数,其中Sn-1为Rn(n2)上的单位球面.本文证明:若∫Sn-1Ω(y′)dσ(y′)=0,则离散型奇异积分TΩ(f)(x)=∑∞k=-∞∫Sn-1f(x-αky′)Ω(y′)dσ(y′)和相关的极大算子TΩ(f)(x)=supN∑∞k=N∫Sn-1f(x-αky′)Ω(y′)dσ(y′)均在L2(Rn)上有界.上述结果推广了Duoandikoetxea和RubiodeFrancia[1]在L2情形下的一个结果  相似文献   

4.
1.问题的提出某电池厂为了提高二氧化锰的利用率,了解正极合剂配方对电池性能的影响,需要对R_6型干电池正极合剂配方进行优选试验,寻找出间隙放电时间长而稳定的配方.选用L_9(3~4)正交表做工艺参数重复优选试验;并用均值分析(ANOM)和极差分析(ANOR)对试验结果进行了分析,找出了R6型干电池正极合剂的优选且稳定的配方.具体设计为:我们对锰粉(A)、碳(B)、氯化氨(A)、水(D)等四个因素进行优选.将各因素分别取三个水平见表1.把A、B.C、D四个因素顺次放入正交表L_9(3~4),且不考虑因…  相似文献   

5.
郑学良 《数学季刊》1998,13(4):29-32
§1. IntroductionandNarratationoftheTheoremIffunctionfisanalyticindomainDandf′(z)≠0atpointz,wedefinetheschwarzianderivativeoffasSf(z)=(f″(z)f′(z))′-12(f″(z)f′(z))2.(1.1)  Foralocallyunivalentholomorphicfunction,itsSchwarzianderivativeisclear.Atpoles,t…  相似文献   

6.
直接法求正交向量组   总被引:1,自引:0,他引:1  
直接法求正交向量组李文汉(清华大学应用数学系100084)求正交向量组的施密特(Schmidt)方法,是线性代数学中常用的一种正交化过程,是每一个学习线性代数的大学生都应掌握的方法.但在有些问题的处理上,采用施密特正交化过程显得太冗繁,不如使用直接法...  相似文献   

7.
本文研究Cliford分析中广义双正则函数的一个非线性边值问题:A(t1,t2)W++(t1,t2)+B(t1,t2)W+-(t1,t2)+C(t1,t2)W-+(t1,t2)+D(t1,t2)W--(t1,t2)=g(t1,t2)ft1,t2,W++(t1,t2),W+-(t1,t2),W-+(t1,t2),W--(t1,t2)[].先讨论解的积分表示式,再研究几个奇异算子,最后用Schauder不动点原理(压缩映射定理)证明了解的存在性(唯一性).目前还没有见到其它国内外学者研究广义双正则函数的非线性边值问题.本文推广了F.Bracks,W.Pincket[10],LeHuang Son[11],R.P.GilbertandJ.L.Buchnan[15]和黄沙[13]的工作  相似文献   

8.
本文证明文[2]中的猜测不成立设f为区间[0,1]上实值函数,满足条件(a)f在[0,1]上有界,(b)f在[0,1]上连续,(c)f(x)不存在,试问是否存在?1982年S.Ricci[1]给出F′+(0)存在的例子:最近J.klippert[2]给出F′+(0)不存在的例子:J.klippert提出如下猜测:如果f满足(a)-(c)并且f的相邻零点之间距离依,α>1,趋近于零,则F′+(0)=0,我们证明上述猜测不真,此外,我们给出F′+(0),存在的一个充分条件。  相似文献   

9.
本文给出施密特(Schmidt)正交化方法的几何解释,以帮助学生弄懂施密特正交化方法的指导思想,以便于牢固掌握之.定理 从n维欧氏空间V的任意一组基a1,a2,…,an出发,都可(经施密特正交化方法)得到V的一组标准正交基e1,e2,…,en;施密特正交化方法为:首先由e1=a1|a1|来决定e1,令bi=ai-(ai,e1)e1-(ai,e2)e2-…-(ai,ei-1)ei-1,并令ei=bi|bi|(i=2,3,…,n),于是便可得到V的一组标准正交基e1,e2,…,en.当n=3时,上述…  相似文献   

10.
李成岳  龙以明 《数学学报》2002,45(2):349-354
本文利用临界点理论中的山路引理,证明了二阶Hamilton系统 -L(t)u+ W′u(t,u)=0存在非平凡的同宿轨道,其中L(t)y·y≥λ|y|2,y∈Rn,λ>0,L(t)和 W(t,u)关于变量t没有周期性假设.  相似文献   

11.
顾及降雨及温度因子的卡尔曼滤波模型   总被引:1,自引:0,他引:1  
考虑到处于不同位置的滑坡变形监测点,由于它们所处的位置不同,各种环境因素对它们的影响及影响程度也不同,因此它们的变形规律也不同.首先通过计算比较找出剩余标准差最小的变形与时间、大气降雨量、温度相关关系的单因子模型,再将这些单因子模型通过叠加,组成多因子模型,然后将变形与时间、大气降雨量、温度相关关系的多因子模型的模型参数看作含有动态噪声的状态向量,建立卡尔曼滤波模型.实例计算表明这种建模方法效果较好.  相似文献   

12.
A stock pollutant is defined as a residual waste that might accumulate over time. This paper examines some of the important distinctions between degradable and nondegradable stock pollutants and between nondegradable stock pollutants with known versus uncertain environmental cost. The latter case is examined using the more recent literature on stochastic control with Brownian motion. The presence of irreversibility and uncertainty is known to lead to more conservative investment rules and places a value on the preservation of options. In the case of a nondegradable stock pollutant with Brownian environmental cost, options are preserved by stopping accumulation at a lower level than in the corresponding certainty-equivalent problem. The model presented in this paper permits the derivation of closed-form stopping rules. For a simple numerical problem, the optimal nondegradable stock with Brownian environmental cost was 20 to 45 percent lower than the optimal level with known environmental cost. The empirical study of an actual nondegradable stock pollutant will require time series data on private and social cost in order to estimate drift and variance parameters which will influence the actual extent to which the optimal stock is less than the certainty-equivalent stock.  相似文献   

13.
Some systematic studies have been carried out on the influence of temperature on the photometric determination of silicon by the molybdenum blue procedure. It has been shown that temperature exerts a distinct influence on the colour intensities involved in the different procedures and the extent of this influence depends largely on the nature of the acid medium and the reducing agent employed. Ascorbic acid has been successfully employed to overcome the influence of temperature. Our thanks are due to the management of the Tata Iron and Steel Company for permitting the publication of this paper.  相似文献   

14.
This paper investigates the extent to which consumers' demographic factors influence their financial policy purchasing behaviours and also explores how the external economic environment affects consumers' propensities to purchase financial products. The Cox proportional hazard model is used to explore these issues. The results suggest that consumer decisions on the timing of financial product purchases are largely explained by changes in the economic environment in terms of stock market, the housing market, average earnings, consumer confidence, and interest rates. The influence of customer demographic factors is also important but secondary.  相似文献   

15.
The Perron-Frobenius theory of a positive operator T (defined on an ordered space E) is developed from an extremal characterization of its largest eigenvalue. This characterization has manifest intrinsic interest. Additionally, it is used to give a particularly revealing derivation of the basic results concerning the existence, multiplicity, and distribution of the eigenvalues of T of maximum modulus. A significant feature of this derivation is that the customary assumptions that the space E be complete and/or that its positive cone have a nonvoid interior are often unnecessary or can be replaced by weaker hypotheses more amenable to practical applications (see 1, 3). The extremal characterization proof of the distribution properties of the eigenvalues of maximum modulus is new in the infinite dimensional case. Also, several new results on the extent of applicability of the extremal characterization are given  相似文献   

16.
A brief survey of the literature on sojourn time problems in single node feedback queueing systems is presented. The derivation of the distribution and moments of the sojourn time of a typical customer in a Markov renewal queue with state dependent feedback is considered in depth. The techniques used relate to the derivation of a first passage time distribution in a particular Markov renewal process. These results are applied to birth-death queues with state dependent feedback. For such models an alternative approach using the theory of Markov chains in continuous time is also examined.  相似文献   

17.
18.
The charging of amino acids by their cognate transfer RNA (tRNAs) is central to modern translation and links evolution of the genetic code with chronologies that describe the use of amino acids in an emergent protein world. Although it is commonly accepted that only few of the canonical amino acids were initially coded and charged by tRNA, the composition of this early group of amino acids has been controversial. To uncover evolutionary patterns embedded in the structure of these molecules, we conducted phylogenetic analyses of 42 structural characters scored from the cloverleaf secondary structures of 571 tRNAs from organisms belonging to the three domains of life, viruses, and bacteriophages. Results show that class II tRNA molecules containing a long variable arm, including tRNASec, tRNASer, tRNATyr, and tRNALeu, were ancestral compared to those lacking this structural feature. This suggests that selenocysteine (Sec), serine (Ser), tyrosine (Tyr), and leucine (Leu) were among the first amino acids to be charged by their cognate tRNAs and that they may represent the first group of amino acids with functional specificities linked to modern biochemistry. Results also suggest that the stop codon UGA, which also codes for Sec, may be the oldest codon to have a modern functional role in the history of the genetic code. Finally, the charging of amino acids by cognate tRNAs appear to have occurred once the canonical cloverleaf structure was fully realized in evolution and before amino acid specificities and organismal domains of life diversified. © 2008 Wiley Periodicals, Inc. Complexity, 2009  相似文献   

19.
The dual reciprocity boundary element method employing the step by step time integration technique is developed to analyse two-dimensional dynamic crack problems. In this method the equation of motion is expressed in boundary integral form using elastostatic fundamental solutions. In order to transform the domain integral into an equivalent boundary integral, a general radial basis function is used for the derivation of the particular solutions. The dual reciprocity boundary element method is combined with an efficient subregion boundary element method to overcome the difficulty of a singular system of algebraic equations in crack problems. Dynamic stress intensity factors are calculated using the discontinuous quarter-point elements. Several examples are presented to show the formulation details and to demonstrate the computational efficiency of the method.  相似文献   

20.
The present paper deals with derivations of noncommutative Arens algebras. We prove that every derivation of an Arens algebra associated with a von Neumann algebra and a faithful normal finite trace is inner. In particular, each derivation on such algebras is automatically continuous in the natural topology, and in the commutative case, even for semi-finite traces, all derivations are identically zero. At the same time, the existence of noninner derivations is proved for noncommutative Arens algebras with a semi-finite but nonfinite trace.  相似文献   

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