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1.
In the theory ofK-quasiconformal mappings, Mori's theorem shows thatK-quasiconformal mappings on the unit disk satisfy the Hölder condition, where the coefficient 16 is best possible. In this paper, we prove that self-μ(z)-homeomorphisms on the unit disk have an analogical result to Mori's theorem when the integral mean dilatations are controlled by log function. An unimprovable inequality is obtained.  相似文献   

2.
In this note we study the property(ω),a variant of Weyl's theorem introduced by Rakoevic,by means of the new spectrum.We establish for a bounded linear operator defined on a Banach space a necessary and sufficient condition for which both property(ω) and approximate Weyl's theorem hold.As a consequence of the main result,we study the property(ω) and approximate Weyl's theorem for a class of operators which we call the λ-weak-H(p) operators.  相似文献   

3.
A complete grid G_(m,n) is the cartesian product of two paths P_m and P_n. In this paper, it is proved that a class of complete grids with two vertices removed are hamiltonian. This result settles a conjecture of S.M. Hedetniemi, S.T. Hede tniemi and P.J. Slater in positive.  相似文献   

4.
In this note, we prove that if G is a finite group, then G is p-nilpotent if and only if there exists a positive integer n such that for any x,y∈G.  相似文献   

5.
田立根 《数学季刊》1996,11(3):91-93
Hurewicz-Radon theorem [1] gives a sufficient and necessary condition about the existence of an orthogonal multiplication f:Rk×Rn→Rn. In this paper,we shall discuss two extensions of the theorem.that is,the sufficient and necessary conditions about the existence of an orthogonal multiplication f:Rk×Rn→Rn 1or f:Rk×Rn→Rn 2  相似文献   

6.
ANoteonSupplementingRadicalsRichardWiegandt(MathematicalInstitute,HungarianAcademyofSciences,P.O.Box127,Budapest,Hungary)Abst...  相似文献   

7.
Let D={z:|z|<1} and let K(D) denote the set of all functions analytic in D with the usual topology of uniform convergence on compact subsets of D. Let S be the class of function f(z) =z+a_2z~2+…analytic and univalent in D. Then S is a compact subset of K(D). A function f∈S is said to be a support point of S if it maximizes Re{L} over S for some continuous comp-  相似文献   

8.
ANoteonWeaklyImplicativeIdealLiuyonglin(Dept.ofMath.,FujianTeacher’sCollege,Nanping353000)ANoteonWeaklyImplicativeIdealLiuyon...  相似文献   

9.
In this paper we show that the weakly -Engel conditions are closely related to the existance of normal -complements; while the -Engel conditions are closely related to the -nilpotent groups.AMS Subject Classification (2000): 20D20  相似文献   

10.
Strong compactness results for families of functions in seminormed nonnegative cones in the spirit of the Aubin-Lions-Dubinski? lemma are proven, refining some recent results in the literature. The first theorem sharpens slightly a result of Dubinski? (in Mat. Sb. 67(109):609–642, 1965) for seminormed cones. The second theorem applies to piecewise constant functions in time and sharpens slightly the results of Dreher and Jüngel (in Nonlinear Anal. 75:3072–3077, 2012) and Chen and Liu (in Appl. Math. Lett. 25:2252–2257, 2012). An application is given, which is useful in the study of porous-medium or fast-diffusion type equations.  相似文献   

11.
In 1911, Toeplitz made a conjecture asserting that every Jordan curve in $\mathbb{R}^{2}$ contains four points forming the corners of a square. Here Conjecture C is presented, which states that the side length of the largest square on a closed curve that consists of edges of an n×n grid is at least $1/\sqrt{2}$ times the side length of the largest axis-aligned square contained inside the curve. Conjecture C implies Toeplitz’ conjecture and is verified computationally for n≤13.  相似文献   

12.
This paper is concerned with two results for(α,β,γ)-superderivations of general superalgebras over the field of complex numbers.  相似文献   

13.
Let F be a field, R be an F-algebra having SVD property['], R+ = {a e Rla = a}. In[2], we proved thatLemma 1 Let R be an F-algebra which having SVD proPerty Then R+ is a sub6e1d inF, R+ is a fOrmaIly rea1 6eId, and R+ is Pythagorean with no zerChdivisor.In the proof of Lernma 1 of [2], thereis this step: "FOr any a E R+ l clearly, there ekistsd E R+ n F such that a2 = ad = a', thus a = la E F, is fOllOws that R+ C F".Recently, paper [11 shows that "The proof of this step is no…  相似文献   

14.
ANoteontheRangeoftheElementaryOperator△_(AC)SunHongwei(孙宏伟)LuShijie(鲁世杰)(DepartmentofMathematics,ZhejiangUniversity,Hangzhou,...  相似文献   

15.
杨明升  张明 《数学季刊》1997,12(2):95-98
s51.IntroductionLetMbeadifferentiablemanifo1dofdimensionn,ifMadmitsa(l,l)-tensorfieldgl,aPoSitivedefiniteRiemannianmetricg,avectorfieldeandal-formVwhichsatisfythefollow-ingconditions.thensuchamanifoldMiscalledaPara-SasakianmanifoldorbrieflyaP-Sasakianmanifoldby7'.AdatiandK.Matsumoto[ljwhichareconsideredasspecialcaseofanalmostparacontactmanifoldintroducedbyI.Sato[2].WhereVdenotestheoperatorofcovariantdifferentiationwithrespecttothemetrictensorg'X(M)denotesthesetofdifferentiablevectorfiel…  相似文献   

16.
In this note, we study the global existence of classical solutions for the viscous Cahn-Hilliard equation with spatial dimension n ≤ 5. Based on the Schauder type estimates and energy estimates, we establish the global existence of classical solutions.  相似文献   

17.
It is well known[l]that a closed linear operator A with dense domain in(an ordered)Banach space E senerates a C_O—semigroup if and only if the resolvent set p(A)contains(ω,+∞),andsup{‖(λ-ω)~nR(λ,A)~n‖:λ>ω,n∈N}<+∞(1)for someω.Sometimes,the condition(l)is not easy to verify.However,for the socalled resolvent positive operators(that is for someω,p(A)(?)(ω,+∞)and for allλ>ω,R(λ,A)=(λ-A)~1≥0),in[2],there are some easy-verified conditions.Here in thisnote,we establish another easy-verified condition.Let E_+be the positive cone of E,and  相似文献   

18.
An elementary fact in the theory of probability is that there exists such random varibles X, Y which are both non indepent and uncorrelated. A wellknown example is that (X,Y) has a density function  相似文献   

19.
J.P. Roudneff as well as R. Aharoni and R. Ziv conjectured that every τ-critical hypergraph has at most $\left( {\begin{array}{*{20}{c}} {\tau + 1} \\ 2 \end{array}} \right)$ edges. In this note we prove this conjecture for τ ≤ 5, and obtain a nontrivial upper bound for general τ.  相似文献   

20.
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