试题研讨(14)

试题 ( 2 0 0 3年省际重点中学大联考 )设数列 {an}的前 n项和 Sn =n2 ( an + 1 ) ,n∈N+ ,a2 =a.( 1 )求证 :数列 {an}为等差数列 ;( 2 )若 a =3,Tn =a1a2 - a2 a3 + a3 a4-a4a5+… + ( - 1 ) n-1anan+ 1,求 Tn.命题溯源　此题是在 1 993年上海市高考试题 ( 2 5)的基础上 ,根据 1 994年全国高考试题 ( 2 5)改编的 .主要考查等差数列的基础知识、数学归纳法及推理论证能力 .原解思路　由　 Sn =n2 ( an + 1 )　得a1=1 ,又 a2 =a,则可猜想an =1 + ( n - 1 ) ( a - 1 ) ( * )下面用数学归纳法加以验证 .1 n =1、n =2时 ( * )式都成立 ;2假设…     

巧用“项”证明数列不等式

数列{an}的前n项和Sn与项an满足关系： an={S1 （n=1）, Sn-Sn-1（n≥2）,类此可得到各项都不为零的数列{bn}的前n项各Tn与项bn满足关系：     

两种度序列图的匹配等价图类

刻画了度序列为π(G) ={ 1,3,2 n-2 }和π(G) ={ n - 2 ,n - 4,(n - 3) n-2 }的图 G的匹配等价图类 .     

P2n和Pnn-1的均匀邻强边色数

对阶至少为3的简单连通图G的k-正常边染色法f,若对任意uv∈E(G)有C(u)≠C(v),||E|-|Ej||≤1,i,j=1,2,…,k.其中C(u)={f(uv)|uv∈E(G)},Ei={uv|f(uv)=i,uv∈E(G)},则称f为G的一k-均匀邻强边染色,简称k-EASEC.并称Xeas(G)=min{k|k-EASEC of G}为G的均匀邻强边色数.给出了图P2n与Pnn-1的均匀邻强边色数.     

2001年全国普通高等学校招生统一考试上海(理工农医类)数学试题及参考解答

一、填空题 (本大题满分 4 8分 )1.设函数 f (x) =2 -x ,　 x∈ (-∞ ,1]log81x,x∈ (1, ∞ ) ,则满足 f (x) =14的 x值为　　 .2 .设数列 { an}的通项为 an=2 n - 7(n∈ N) ,则|a1| |a2 | … |a15|=　　 .3.设 P为双曲线 x24 - y2 =1上一动点 ,O为坐标原点 ,M为线段 OP的中点 ,则点 M的轨迹方程是　　 .4 .设集合 A ={ x|2 lgx =lg(8x - 15 ) ,x∈ R} ,B ={ x|cosx2 >0 ,x∈ R} ,则 A∩ B的元素个数为　　个 .5 .抛物线 x2 - 4 y - 3=0的焦点坐标为　　 .6.设数列 { an}是公比 q >0的等比数列 ,Sn是它的前 n项和 .limn→∞ Sn=7,则…     

Contraction Flow by Certain Curvature of Convex Hypersurfaces

In the following mixed tensors on the hypersurface M Rn+1 under consideration willbe denoted by T={ Tijkl} ,the induced metric by g={ gij} and the second fundamentalform by A={ hij} .We always sum overrepeated indices from1 to n and use brackets forthe inner product on M:〈Tijk,Sijk〉 =gisgjαgkβTijk Ssαβ,　 | T| 2 =〈Tijk,Tijk〉.Setrkl =gkαhαl,Sm(λ1 ,… ,λn) = i1<… 相似文献   

P_n~k(k≡2(mod3))的邻点可区别的强全染色

对简单图 G(V,E) ,V(Gk) =V(G) ,E(Gk ) =E(G)∪ { uv|d(u,v) =k} ,称 Gk为 G的 k次方图 ,其中d (u,v)表示 u,v在 G中的距离 .设 f为用 k色时 G的正常全染色法 ,对 uv∈ E(G) ,满足 C(u)≠ C(v) ,其中C(u) ={ f(u) }∪ { f(v) |uv∈ E(G) }∪ { f(uv) |uv∈ E(G) } ,则称 f 为 G的 k邻点可区别的强全染色法 ,简记作 k- ASVDTC,且称 χast(G) =min{ k|k- ASVDTC of G}为 G的邻点可区别的强全色数 .本文得到了 k≡2 (mod3)时的 χast(Pkn) ,其中 Pn 为 n阶路 .     

形式系统L*(n)的完备性

模糊逻辑命题演算形式系统 L*自 1 997年被提出以来 ,在模糊逻辑与模糊推理的理论与应用中发挥了重要的作用 .系统 L* 的完备性直到最近才由作者给出证明 .本文进一步研究系统 L*的扩张在 n元 R0 链 Wn 上的完备性问题 ,通过构造公式列 ,得到系统 L*的扩张列 { L* (n) } ,使用代数方法证明了对于任何n≥ 3 ,系统 L* (n)关于 Wn 是完备的     

关于任意随机变量序列配重和的一类强偏差定理

设{Xn,n≥1}是在E={0，1)中取值的二值随机序列，{an，n≥1}是[0，1]中取值的一列常数，Wn(ω)=n∑i=1aiXi(ω)，本文利用区间剖分法[1],[2]构造单调函数，研究任意二值随机序列配重和Wn(ω)的一类用不等式表示的定理，即强偏差定理．     

图的点可区别Ⅳ-全染色

设G是简单图,图G的一个k-点可区别Ⅳ-全染色(简记为k-VDIVT染色)f是指一个从V(G)UE(G)到{1,2,…,k}的映射,满足:uv,uw∈E(G),v≠w,有f(uv)≠f(uw);u,v∈V(G),u≠v,有C(u)≠G(v),其中C(u)={f(u)}∪{f(uv)|uv∈E(G)}.数min{k|G有一个k-VDIVT染色}称为图的点可区别Ⅳ-全色数,记为χ_(vt)^(iv)(G).本文给出了双星S_(2n),轮W_n和扇F_n的点可区别Ⅳ-全色数.     

半群PT_n(A)的正则性与格林关系

设X_n={1,2,…,n}并赋予自然序,PT_n是X_n上的部分变换半群.设A■X_n非空,令PT_n(A)={α∈PT_n:imα■A}.讨论了半群PT_n(A)的正则性与格林关系.     

Again Sharpening of a Negative ExponentGeometric Inequality in the Space E~n

DerinitionInageometricinequalitybyaftersimplify,ifturnupgeometricmetricinde-nominatorofafractor,butnoturnupgeometricmetricinnumerator,thencallednegativeex-ponentgeometricinequalitysuchgeometicinequality,isnegativeexponentgecmetricinequalityforshort-LetrandR.denotetheinradiusandcircumradiusofsimplexXinthen-dimensionalEuc-tideanspaceEw,respectively.LetPbearbitraryPOintinsidethe8implexX,andd,,d,,..',d. ,bethedistancefrompointPton lthen-l-dimensionalhyperplane,article[ljobtainanegativeexponent…     

About Knop's Action of the Weyl Group on the Set of Orbits of a Spherical Subgroup in the Flag Manifold

Let G be a connected reductive algebraic group defined on an algebraically closed field k of characteristic different from 2. Let B denote the flag variety of G. Let H be a spherical subgroup of G. F. Knop defined an action of the Weyl group W of G on the finite set of the H-orbits in B. Here, we define an invariant, namely the type, separating the orbits of W.     

树的最大特征值的上界的一个注记

设T是一个树,V是T的顶点集．记dv是υ∈V的度,△是T的最大顶点度．设υ∈V且dw=1．记k=ew+1,这里ew是w的excentricity．设δj′= max{dυ:dist(υ,w)=j},j=1,2,…,k-2,我们证明和这里μ1(T)和λ1(T)分别是T的Laplacian矩阵和邻接矩阵的最大特征值．特别地,记δo′=2．     

On Classification of Projective Varieties with Non-Integral Nef Values

61. IntroductionLetM be an n-dimensional normal projective variety with only Q-Gorenstein, terminalsingUlarities and letL be an ample line bundle on M. KM denotes the canonical divisor, orthe canonical sheaf of M. Assume that KM is not nef. The ne f value of (M, L) is a realnUmber defined as follows:.T = min{r E RIKM rL is ne f }.By the Kawamata rationality theorem, T is a rational number and by the KawamataShokurov base point free theorem, lin(KM AL)l is base point free for m>…     

空间中渐近非扩张型映射的渐近行为

Let X be a uniformly convex Banach space X such that its dual X^＊ has the KK property. Let C be a nonempty bounded closed convex subset of X and G be a directed system. Let ={Tt ： t ∈ G} be a family of asymptotically nonexpansive type mappings on C. In this paper, we investigate the asymptotic behavior of {Ttx0 ： t∈ G} and give its weak convergence theorem.     

Special precovered categories of Gorenstein categories

Let A be an abelian category and P(A)be the subcategory of A consisting of projective objects.Let C be a full,additive and self-orthogonal subcategory of A with P(A)a generator,and let G(C)be the Gorenstein subcategory of A.Then the right 1-orthogonal category G(C)~⊥1 of G(C)is both projectively resolving and injectively coresolving in A.We also get that the subcategory SPC(G(C))of A consisting of objects admitting special G(C)-precovers is closed under extensions and C-stable direct summands(*).Furthermore,if C is a generator for G(C)~⊥1,then we have that SPC(G(C))is the minimal subcategory of A containing G(C)~⊥1∪G(C)with respect to the property(*),and that SPC(G(C))is C-resolving in A with a C-proper generator C.     

Volume of Singular Hyperbolic Sets

Let X be a C~(1+) vector field on a compact Riemannian manifold M with dimension d ≥ 3.Let Λ be a transitive singular hypebolic set with positive volume. We show that Λ = M and Λ is a uniformly hyperbolic set without singularities.     

On the Root-Class Residuality of Certain Free Products of Groups with Normal Amalgamated Subgroups

Russian Mathematics - Let $${\cal K}$$ be a root class of groups closed under taking quotient groups, G be a free product of groups A and B with amalgamated subgroups H and K. Let also H be normal...     

On Dynamics of Infinitely Generated Contractive Mapping Systems on p ℤ p

Let p ≥ 2 be a prime number and ℤp be the ring of p-adic intergers. Let G be a semigroup generated by infinitely many contractive maps on pT