TWO COMMUTATIVITY RESULTS FOR SEMI-PRIME RINGS

1.Introduction.In 1980.V.Gupta [2] provedTheorem A Let R be a semi-prime ring with unit satisfying(i)[x~n,y]-[x,y~n]∈Z(R) (ii)[x~(n+1),y]-[x,y~(n+1)]∈Z(R)for all x,y∈R and a fixed integer n>1,then R is commutative.This theoremimproved a theorem which was established by Harmanci [4] in 1977 that if aring R with unit satisfies the identity(i)[x~n,y]=[x,y~n] (ii)[x~(n+1),y]=[x,y~(n+1)] for all x,y∈Rand a fixed integer n>1,then R is commutative.Later,in 1982,Guo Yuan     

名校基础知识自测 高一年级

一、选择题1.集合M={(x,y)|y=f(x),x∈A}∩{(x,y)|x= 1}(A R)的元素个数为( ). (A)0 (B)1 (C)2 (D)0或12.下列函数中与y=x表示同一函数的是( ). (A)y=x2/x (B)y=(√x)2 (C)y=√x2 (D)y=x53.函数f(x)的定义域为[-1,2],则函数F(x)= f(x) f(-x)的定义域是( ). (A)[-1,2] (B)[-2,1] (C)[-1,1] (D)[-2,2]     

一类2n阶次线性奇异边值问题的正解

利用单调迭代方法给出了一类2n阶次线性奇异常微分方程正解的存在性,得到C~(2n-2)[0,1]和C~(2n-1)[0,1]正解存在的充分必要条件,也得到正解的唯一性.     

A PERTURBATION THEOREM ANDITS APPLICATION

1IntroductionInpractice,manydifferentialequationsandintegrodifferentialeqllationscanbeformulatedasabstractCauchyproblemswhicharedependentonmulti-parameters[l,2,3]whereA(E)areclosedoperatorsonaBanachspaceandEisamulti-parameter.InordertostudydifferentiabilitywithrespecttotheparameterEoftheso-lutionof(l.1),severalstudieshavebeendevotedtothedifferentiabilitywithrespecttoparametersofCO--semigroupwhichisgeneratedbytheoperatorA(e)[l,5,6,7].AninterestingquestionisraisedwhenwestudVthefollowingabstr…     

局部次指数分布的一类卷积封闭性的等价条件及应用

给出了支撑在[0,∞)的局部次指数分布的一类卷积封闭性的若干等价条件,并在适当的条件下推广到了全空间.在此基础上,得到了对称化分布的局部渐近性的结果.上述结果可以蕴涵Embrechts和Goldie(1980)[1]及Geluk(2004)[2]非局部的相应结果,其中部分证明比[2]简单.     

关于一类插值样条

在S_(n△)。中有唯一解.令P_△f=s(x),s(x)是对f(x)关于上述插值问题(1)的解,J.Tzi-mbalario证明投影算子P_△:C~(-1)[a,b]→S_(n△)是有界的,这里C~(-1)[a,b]是[a,b]上有界函数全体所成的空间. J.Tzimbalario的证明是错误的,因为从[1]中(3.6)式通过计算得到的不是(3.7)式,     

一个无限可微函数类的最优埃尔米特插值CSCD

This paper investigates the optimal Hermite interpolation of a class F_(∞) of infinitely differentiable functions on[-1,1]in L_(∞)[-1,1]and weighted spaces L_(p,w)[-1,1],1≤p∞[-1,1]and L_(p,w)[-1,1],1≤p<∞ with w a continuous integrable weight function in(-1,1).We proved that the Lagrange interpolation polynomials based on the ze-ros of polynomials with the leading cofficient 1 of the least deviation from zero in L_(∞)[-1,1]and L_(p,w)[-1,1],1≤p<∞are optimal for 1≤p≤∞.We also give the optimal Hermite interpolation nodes when we ask the endpoints to be included in the nodes.     

THE ELLIPTIC TYPE NODE CONFIGURATION AND INTERPOLATION IN R~2

1.IlltroductionInthispaper,weusetheusualmultivariatenotationac=yi'w'B,iii=if ... j.(if,'',j.EZ )[l'a]andletPnbethe(bivariate)polynomialspaceofallreal(bivariate)polynomialsofdegreeatmostn.NowweintroducetheconceptoftheCurveTypeNodeConfiguration(CTNC):De…     

ON THE RELATIVISTIC BOLTZMANN EQUATION

1IntroductionWearecollcernedwithglobalealstellceofsolutionsoftheinitialvalueproblelllfortherelativisticBoltzlllallnequation(orinbrief,RBE)[1]wilersthedifferelltpartsareexplailledbelow.cp=(t,x)alldpl'=(po,p)respectivelyrepresentafour-dinlellsiollalspace-timedinlensionlessvariablealldafour--dimellsionalulolllentum-energydimensionlessvariable.f=f(t,x,p)isadistributiollf'llllctiollofaolle-particleclassicalrelativisticgaswithoutexterllalforces.W(P,pl;p',pl)isatrallsitiollratewhichdepelldsonlyonti…     

等差数列、等比数列的一个新的性质

结论1已知等差数列{an},r,s,t是互不相等的正整数,则有(r-s)at (s-t)ar (t-r)as=0.证明设等差数列{an}的首项为a1,公差为d,则(r-s)at (s-t)ar (t-r)as=(r-s)[a1 (t-1)d] (s-t)[a1 (r-1)d] (t-r)[a1 (s-1)d]=[(r-s) (s-t) (t-r)]a1 [(r-s)(t-1) (s-t)(r-1) (t-r)(s-1)]d=[(r-s) (s-t) (t-r)]a1 [(rt-st-r s) (sr-tr-s t) (ts-rs-t r)]d=0.此结论可以在知道等差数列中的任意两项的情况下,求出第三项的值.比如问题:已知数列{an}为等差数列,ap=q,aq=p,且p≠q,求ap q.略解由结论1可知,(p-q)ap q [q-(p q)]ap [(p q)-p]aq=0,即(p-q)ap q-pq pq=0,…     

基于变动人口的Solow模型

本文在Solow模型框架中引入随时间变动人口增长函数，并假定人口增长率最终趋于零，证明该模型的解是渐近稳定的，收敛于零人口增长率的经典Solow模型的解。通过引入变动人口增长率，讨论人口过渡时期和人口波动对经济增长的影响，并给出数值计算结果。     

劳动力供给带弹性的Solow模型

本文给出了在劳动力供给带弹性条件下的Ｓｏ１ｏｗ增长模型，给出了经济增长的黄金律和均衡处资本稳定性的证明，并且与不带弹性的Ｓｏｌｏｗ模型作了比较．     

The uniqueness of an entire function sharing a small entire function with its derivatives

In this paper, we prove a theorem on the growth of a solution of a linear differential equation. From this we obtain some uniqueness theorems concerning that a nonconstant entire function and its derivatives sharing a small entire function. The results in this paper improve many known results. Some examples are provided to show that the results in this paper are the best possible.     

随机扰动下的增长模型

以确定性的Solow增长模型为背景,文章将随机扰动引入其中.因此模型中的要素方程从ODE过渡到It SDE,并对其作某些定性的分析.进而运用二次Liapunov函数等方法对随机Solow模型的零解的稳定性及其平稳分布进行了有益的探索,得出了一些有意义的结果.文章的主要结论是:随机干扰将实质性地改变由确定性增长模型所描述的经济增长路径.     

基于Douglas生产函数的广西经济增长因素分析

基于柯布-道格拉斯(Douglas)生产函数,建立1995年至2012年广西经济发展模型,利用R统计软件求出资本和劳动力的产出弹性系数分别为0.81和0.19,再利用索洛增长速度方程求出资本投入、劳力投入和技术进步对广西经济增长的贡献率分别为141.8%、1.5%、-43.3%,这三个因素分别拉动经济增长15.8百分点、0.2百分点和-4.8百分点.表明了资本投入是广西近十几年来经济增长的决定性因素,劳动投入和技术进步对经济增长的贡献比较有限,广西的经济还是处于粗放投入型的增长模式.     

基于产业结构和能源视角的浙江省经济增长的实证分析

本文从Solow模型出发,同时将产业结构、能源和对外贸易因子纳入到Cobb-Douglas生产函数中,建立主成分回归模型,实证研究了产业结构和能源消费对经济增长的作用程度.本文同时基于能源与产业结构的分析,是对已有研究的一次有益尝试.回归结果显示:产业结构因素和能源因素对浙江省经济增长较其他因素具有较强的正向带动作用.最后,本文给出了相关建议,建议相关部门尤其要做好产业结构优化升级与能源消费结构优化的"两手抓"工作。     

随机Solow经济增长模型及其解的性质

１９８７年诺贝尔（Ｎｏｂｅｌ）经济学奖获得者Ｓｏｌｏｗ教授，建立了确定性的经济增长模型（１９５６年）．它比较真实地描述了现实世界申的确定性的经济增长状况，然而对不确定性的现象，往往误差较大，甚至失效．本文把Ｓｏｌｏｗ模型扩展到随机情形，扩展了Ｂａｎａｃｈ压缩映像原理和不动点定理，获得了随机Ｓｏｌｏｗ模型主要方程和随机解的一些性质．     

Growth and distortion theorems on subclasses of quasi-convex mappings in several complex variables

In this paper, the refining growth and covering theorems for f are established, where f is a quasi-convex mapping of order α and x = 0 is a zero of order k + 1 of f(x) − x. As an application, we obtain the upper and lower bounds on the distortion theorem of f(x) defined on the unit polydisc of ℂ ⁿ . The upper bound of the distortion theorem for f(x) defined on the unit ball of a complex Banach space is also given. Our results extend the growth and distortion theorems for convex functions of one complex variable to quasi-convex mappings of several complex variables.     

Erdős-Turʼan-Type Discrepancy for the Zeros of Rational Functions

In 1950 P. Erdős and P. Turán published a discrepancy theorem for the zeros of a polynomial. Therein, the maximum deviation of the normalized zero counting measure from the equilibrium measure of the unit circle is estimated. Many other discrepancy theorems and related propositions about weak-star-convergence of the zero distribution of a sequence of polynomials were proved during the last decades. For several years the weak-star-convergence of the zero distribution of a sequence of rational functions is also studied. The main result of this paper is a discrepancy theorem for the zero distribution of a rational function which generalizes and sharpens previous propositions about weak-star-convergence of the zero counting measure of sequences of rational functions and known discrepancy theorems for polynomials.     

Stability analysis of mathematical models for nonlinear growth kinetics of breast cancer stem cells

Cancer stem cells are responsible for tumor survival and resurgence and are thus essential in developing novel therapeutic strategies against cancer. Mathematical models can help understand cancer stem and differentiated cell interaction in tumor growth, thus having the potential to help in designing experiments to develop novel therapeutic strategies against cancer. In this paper, by using theory of functional and ordinary differential equations, we study the existence and stability of nonlinear growth kinetics of breast cancer stem cells. First, we provide a sufficient condition for the existence and uniqueness of the solution for nonlinear growth kinetics of breast cancer stem cells. Then we study the uniform asymptotic stability of the zero solution. By using linearization techniques, we also provide a criteria for uniform asymptotic stability of a nontrivial steady‐state solution with and without time delays. We present a theorem from complex analysis that gives certain conditions that allow for this criteria to be satisfied. Next, we apply these theorems to a special case of the system of functional differential equations that has been used to model nonlinear growth kinetics of breast cancer stem cells. The theoretical results are further justified by numerical testing examples. Consistent with the theories, our numerical examples show that the time delays can disrupt the stability. All the results can be easily extended to study more general cell lineage models. Copyright © 2017 John Wiley & Sons, Ltd.