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1.
1 .垂钓      2 .客运规则    3 .附则      4.八刀       5 .对症下药6.我有一毛钱  7.待命出发  8.二牛打架  9.五角钱一回  1 0 .找工作1 1 .双双过磅  1 2 .考试舞弊  1 3 .五角钱  1 4.五四三二一(答案在本期内找 )数学名词谜语答案1 .等于 (鱼 )     2 .乘法     3 .加法      4.分解      5 .开方6.余角 7.等差   8.对顶角   9.一元二次   1 0 .求值  1 1 .对称 1 2 .假分数   1 3 .半圆   1 4.倒数数学名词谜语…  相似文献   

2.
文 [1 ]给出了等差数列的一个性质 :设 {an}是以 d为公差的等差数列 ,则有a1+ a2 +… + ann =am+ 1+ am+ 2 +… + an-mn - 2 m .本文运用类比的方法 ,得到等比数列的一个类似的性质 .性质 设 {an}是公比为 q( q>0 )的等比数列 ,则有( a1a2 … an) 1n =( am+ 1am+ 2 … an-m) 1n-2 m,其中 n >2 m.证明 当 n为奇数时 ,n- 2 m也为奇数 .( a1. a2 .… . an) 1n  =( a1. a1q . a1q2 .… . a1qn-1) 1n  =( an1. q1+ 2 + 3 +… + n-1) 1n,  =( an1. qn( n-1)2 ) 1n =a1. qn-12 .( am+ 1. am+ 2 .… . an-m) 1n-2 m  =( a1qm . a1qm+ 1.… . a…  相似文献   

3.
51.IntroductionIntheirpaperL2j,LiuYaxingandLiQishengintroducedtheconceptofthegraphlikemanifolds.Slncegraphlikenlalifoldscanbe1ookeduponasgenera1izat1onofgraphsandcontalnthetorusandtheKleinbott1easspecialcases,theymakeupaimportantclassoftopologicalmanifolds.Thetopicabouttopologlcclassificat1onofgraphlikemanifoldswasresearchedln[2j,L4j,L5j,L6jand[7j.There,calculatingofhomeomorphicclassesisonthebas1softhefo1low1ngs:1.isomorphicgraphscanbcregardedasthesamecontraction;2.thetwistoperationpreserv…  相似文献   

4.
一、选择题:本大题共口小题,共60分.1.复数11 -ii i3的值是A.0B.1C.-1C.12.函数f(x)=1 log2x与g(x)=2-x 1在同一3.直角坐标系下的图象大致是li mx→1x2-12x2-x-1=4.A如.图0,ABCBD.1-AC.12D.231B1C1D1为正方体,下面结论错误的是A.BD∥平面CB1D1B.AC1⊥BDC.AC1⊥平面CB1D1D.异面直线AD与CB1角为60°5.如果双曲线x42-y22=1上一点P到双曲线右焦点的距离是2,那么点P到y轴的距离是6.A设.球43O6的半B径.是2316,A、BC、C.26D.23是球面上三点,已知A到B、C两点的球面距离都是π2,且二面角B-OA-C的大小为3π,则从A点沿球面经B、…  相似文献   

5.
Let H1,H2 be subgroups of a finite group G. Assume that G=∪i=1mH2yiH1=∪j=1nH1gjH1 and that y1=1,g1=1.Let Di be the set consisting of right cosets of H2 contained in H2yiH1 and let dj(j=1, . . . ,n) be the set consisting of right cosets contained in H1gjH1.We define the n×m matrix Mz(z=1, . . . ,m) whose columns and rows are indexed by Di and dj respectively and the (dk,Dl) entry is |Dzgk∩Dl|. Let M=(M1, . . . ,Mm). Assume that 1H1G and 1H2G are semisimple permutation modules of a finite group G. In this paper, by using the matrix M , we give some sufficient and necessary conditions such that 1H1G is isomorphic to a submodule of 1H2G.As an application, we prove Foulkes' conjecture in special cases.  相似文献   

6.
一、选择题 (本大题满分 3 6分 ,每小题 3分 )1 . -2与 2m互为相反数 ,那么m等于 (  ) .A . -1  B .1  C .14  D . -142 .我国某年石油产量约为 1 70 0 0 0 0 0 0吨 ,用科学记数法表示为 (  ) .A .1 .7× 1 0 - 7吨   B .1 .7× 1 0 7吨C .1 .7× 1 0 8吨D .1 .7× 1 0 9吨3 .下列计算正确的是 (  ) .A .( -1 ) 0 =-1  B .3× ( 12 ) - 2 =3× 2 2C .( 5 3) 2 × 5 4=5 0 D .( -3 5)÷ ( -3 ) 3=-3 24.下列根式中 ,与 1 2 是同类二次根式的是 (  ) .A . 2  B . 3  C . 5  D . 75 .化简 ( 1a-1b)·…  相似文献   

7.
一、选择题 (本大题共 3 6分 ,每小题 3分 )1 .已知 2x =3y(x≠ 0 ) ,则下列比例式成立的是(  ) .A .x2 =y3     B .x3 =y2C .xy =23   D .x2 =3y2 .一个角是它余角的 4倍 ,则这个角的补角为(  ) .A .1 62°  B .72°  C .1 0 8°  D .1 44°3 .下列式子中 ,总能成立的是 (  ) .A .(a -1 ) 2 =a2 -1B .(a +1 ) 2 =a2 +a+1C .(a +1 ) (a-1 ) =a2 -a+1D .(a +1 ) ( 1 -a) =1 -a24.下列图形中 ,不是轴对称图形的是 (  ) .5 .下列各个方程中 ,无解的方程是 (  ) .A .x+2 =-1B .3 (x -2 ) +1 =0C .x2 -1 =0D . xx-1 =26.…  相似文献   

8.
1IntroductionThegoalofthispaperistoinvestigatetheglobalexistenceandlargetimebehaviorofsolutionstoareactingflowwithboundaryeffectsast-oo.ThesystemillEulerianformcallbewrittenaswhichwasproposedbyR.J.LeVequeandothersin[8]tomodelthemotiollofreacti11ggaswithtwomodes.Wl1ere,p7'isthedensityofthemajormodeandpscorrespolldstotllellli1lormode,r s=l.itisthevelocity,andp=pc'(r Ps)isthepressllrewllichcallbederivedbyAvogadro'sLaw.Here,cisthesouudspeedoftl1emajorn1ode.Thepara1lleterPprovidessometenuousliu…  相似文献   

9.
一、选择题:本大题共10小题,共50分.1.若等差数列{an}的前3项和S3=9且a1=1,则a2等于()A.3B.4C.5D.62.命题“若x2<1,则-11或x<-1,则x2>1D.若x≥1或x≤-1,则x2≥13.若三个平面两两相交,且三条交线互相平行,则这三个平面把空间分成()A.5部分B.6部分C.7部分D.8部分4.若x 1xn展开式的二项式系数之和为64,则展开式的常数项为()A.10B.20C.30D.1205.在△ABC中,AB=3,A=45°,C=75°,则BC等于()A.3-3B.2C.2D.3 36.从5张100元,3张200元,2张300元的奥运预赛门票中任取3张…  相似文献   

10.
I初一年级l1.设a一1 虿1十了1十,百1十,i1, 。b一虿1十,了1十,百1十i1, 则原式一n(6 吉)一6(n 吉) 0 O 一吉cn刊一吉.2.’-. 3。”=81’”,4。。。一64’”,5。。。:25’”, 又。.。 81>64>25, .‘. 3。”>4。。。>5。”.3.(1)由题意得:(zy一1)。 1 y 1 l===0. .。.y一一1,z一一1. (2)。-. 2。·5y 2—2002, .。. 2,·5,一2000—2‘·5。, .。.z一4,y一3.原式一1.I初二年级I1.(1)(z。 4z 6)(z。 8z 6); (2)(z 2)(z一5)(z。一3z 8).2.由①得z一6—3y代入②得 6—2(6—3.y)y 2z。一0, .‘..y=1,z=0. ·‘·z一3. .。. z。y’。一3。’。=9.3…  相似文献   

11.
We prove that the finite element method for one-dimensional problems yields no discretization error at nodal points provided the shape functions are appropriately chosen. Then we consider a biharmonic problem with mixed boundary conditions and the weak solution u. We show that the Galerkin approximation of u based on the so-called biharmonic finite elements is independent of the values of u in the interior of any subelement.  相似文献   

12.
郑权  余德浩 《计算数学》1997,19(4):438-448
1.引言双调和方程边值问题的一个力学背景是薄板弯曲问题.对于有界区域上的双调和方程,可以直接利用协调元和非协调元求解18,10].我们考虑双调和方程Dirichlet外边值问题其中0是充分光滑闭曲线ro之外的无界区域,naro关于0的单位外法向量.引理1.且卜].若。0EH’/‘(几),gEH‘/‘(fo),则问题(1.1)在W0z(fi)中有唯一解·这里由迹定理,可找到一个具有紧支集的函数识。。,g)E护(炉)满足可。0;g)【F。=。0和则问题(1.1)等价于如下齐次边值问题其中f—一面‘B有紧支集.边值问题(工.2)又可转化为变分问…  相似文献   

13.
A penalty method for mixed finite element methods is formulated and studied. The Herrmann-Miyoshi scheme for the biharmonic equation is considered. The main idea is to build a perturbed problem with two parameters playing the role of penalties. The perturbed problem is constructed by replacing principal conditions in the mixed variational formulation at the interface by natural conditions containing parameters. Discretization of the perturbed problem is effected by a finite element method. Estimates for the norm of the difference between the solutions of a discrete perturbed problem and of an initial value problem are derived depending on the mesh size and penalties. Recommendations are given as to how to choose penalties so as to fit a mesh size.  相似文献   

14.
The aim of this paper is to analyze mathematically the method of fundamental solutions applied to the biharmonic problem. The key idea is to use Almansi-type decomposition of biharmonic functions, which enables us to represent the biharmonic function in terms of two harmonic functions. Based on this decomposition, we prove that an approximate solution exists uniquely and that the approximation error decays exponentially with respect to the number of the singular points. We finally present results of numerical experiments, which verify the sharpness of our error estimate.  相似文献   

15.
Two-level additive Schwarz preconditioners are developed for the nonconforming P1 finite element approximation of scalar second-order symmetric positive definite elliptic boundary value problems, the Morley finite element approximation of the biharmonic equation, and the divergence-free nonconforming P1 finite element approximation of the stationary Stokes equations. The condition numbers of the preconditioned systems are shown to be bounded independent of mesh sizes and the number of subdomains in the case of generous overlap.

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16.
解Stokes特征值问题的一种两水平稳定化有限元方法   总被引:2,自引:1,他引:1  
基于局部Gauss积分,研究了解Stokes特征值问题的一种两水平稳定化有限元方法.该方法涉及在网格步长为H的粗网格上解一个Stokes特征值问题,在网格步长为h=O(H2)的细网格上解一个Stokes问题.这样使其能够仍旧保持最优的逼近精度,求得的解和一般的稳定化有限元解具有相同的收敛阶,即直接在网格步长为h的细网格上解一个Stokes特征值问题.因此,该方法能够节省大量的计算时间.数值试验验证了理论结果.  相似文献   

17.
本征值有限元近似的一个抽象误差估计式   总被引:6,自引:0,他引:6  
设T:LZ(fi)MLZ(fi)是自共轭全连续算子,SgCLZ(fi)是分片。次有限元空间,几:LZ、St是有限秩自共轭算子,IITh-Tllo、0(h、0).考虑本征值问题:及其近似用(·,·)和DD·D【。·分别表示h(m中内积和范数·ID·卜F表示w认}(m中范数,简记D卜队。为D卜卜·因为T自共轭全连续,所以它有可数无穷个本征值h,人,...人,....其相应的本征函数(2丹构成完全标准直交系,所以VZELZ(m设几的本征值为A。l,汕。,...,汕n,相应的本征函数为如山,卜则。二1·不失一般性,可EitL。设tik一大干二>,E是到Ah对应的本…  相似文献   

18.
本文针对双调和算子特征值问题设计了基于混合变分形式的三角谱元逼近格式,其基函数采用指标为(-1,-1,-1)的广义Koornwinder多项式.在H~1-及H_0~1-正交谱元投影的逼近理论基础上,我们建立了双调和算子特征值与特征函数的收敛性估计;它关于网格尺寸h是最优的,关于多项式次数M是次优的.然而,在H_0~2-正交谱元投影的最优估计假设前提下,关于M的次优收敛阶估计则提升为最优.此外,Koornwinder分片多项式逼近的结果还表明,在带权Besov空间范数的度量下,对于存在着区域角点奇性的双调和算子特征值问题,谱元方法的收敛阶能达到h-型有限元方法的2倍.最后,本文的数值实验结果展示了谱元逼近格式的高效性,同时也验证了相关理论的正确性.  相似文献   

19.
Summary. We study preconditioners for the -version of the boundary element method for hypersingular integral equations in three dimensions. The preconditioners are based on iterative substructuring of the underlying ansatz spaces which are constructed by using discretely harmonic basis functions. We consider a so-called wire basket preconditioner and a non-overlapping additive Schwarz method based on the complete natural splitting, i.e. with respect to the nodal, edge and interior functions, as well as an almost diagonal preconditioner. In any case we add the space of piecewise bilinear functions which eliminate the dependence of the condition numbers on the mesh size. For all these methods we prove that the resulting condition numbers are bounded by . Here, is the polynomial degree of the ansatz functions and is a constant which is independent of and the mesh size of the underlying boundary element mesh. Numerical experiments supporting these results are reported. Received July 8, 1996 / Revised version received January 8, 1997  相似文献   

20.
Finite element derivative superconvergent points for harmonic functions under local rectangular mesh are investigated. All superconvergent points for the finite element space of any order that is contained in the tensor-product space and contains the intermediate family can be predicted. In the case of the serendipity family, results are given for finite element spaces of order below 6. The results justify the computer findings of Babuska, et al.

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