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1.
For p ∈ R, the generalized logarithmic mean L p (a, b) and Seiffert’s mean T (a, b) of two positive real numbers a and b are defined in (1.1) and (1.2) below respectively. In this paper, we find the greatest p and least q such that the double-inequality L p (a, b) < T (a, b) < L q (a, b) holds for all a, b > 0 and a ≠b. 相似文献
2.
1IntroductionTherehavebeensomeinterestingresultsinstudyingtheflowofconvexhypersurfacesintheEuclideanspacebyfunctionsOftheirprincipalcurvatures.BeingviewedasanextensionOfthetheoremOfGageandHedton[3],Huiskellprovedin16]thatdeformingconvexhypersurforesbytheirmeancurysturefunctiollsconvergetoaroundsphereinasense.FollowingthemethodsOfHuiskell[6]andTso[IOI,Chowshowedin[1]thatthesame.statementasin.[6]reconstrueifthemeancurvatureisreplacedbythen-throotoftheGauss-Kroneckercurvature.FOrgenerality… 相似文献
3.
§1. IntroductionIt is a classical topic to study, for quadratic number ?elds F = Q(√2p) with a prime p,the exact 2-power dividing the narrow class number h (F) and the norm of the fundamentalunit ε of F.The 2-primary subgroup of the narrow class group … 相似文献
4.
We give a lower bound for the first gap λ_2—λ_1 of the twolowerst eigenvalues of the Schr(o|¨)dinger operator-△+W(p) with the Dirichletboundary condition and a strictly convex potential W(p)on M in which M is acompact simple Riemannian manifold with smooth strictly convex boundary (?)MHere a compact Riemannian manifold M is said to be simple if M~(?)M istopologically R~2.We prove thatλ_2-λ_1≥(π~2)/(d~2)+min{0,-(n-1)K}where d is the diameter of M and-(n-1)K,(K≥0)the lower bound of theRicci curvature of M.This work generalizes the results in the classical Eucli-dean situation due to Singer,Wong and Yau,Yu and Zhong to a kind of curvedRiemannian manifold. 相似文献
5.
PROPERTIES IN THE LARGE OF QUADRATIC SYSTEMS IN THE PLANE 总被引:1,自引:0,他引:1
韩茂安 《数学年刊B辑(英文版)》1989,(3)
The author proves that any quadratic system in the plane can be changed into the quadratic system (E_1) or (E_2) by means of linear transformations, and then gives a necessary and sufficient condition for the systems (E_1) and (E_2) to be bounded for t≥0 and to have precisely one monotone unboundol orbit for t≥0 respectively. 相似文献
6.
THE VARIATION OF INVARIANT LINES AND LIMIT CYCLES FOR A QUADRATIC DIFFERENTIAL SYSTEM 总被引:1,自引:0,他引:1
1IntroductionConsidertherealquadraticdiferentialsystemx=-y+δx-4x2+3xy+13y2y=x(1-13x-y).(1)First,forconvenience,wedenotethetwo... 相似文献
7.
Sun Jiachang 《数学年刊B辑(英文版)》1983,4(4):493-500
Some generalizations of the classical Mean Values and their inequalities are presented inthis paper,using B-spline functions.The new generalized Means can be applied to nonlineardifference schemes for solving O.D.E.and P.D.E.with singularities([6,7,8]). 相似文献
8.
9.
Zhou Feng 《数学年刊B辑(英文版)》1998,19(3):249-254
§1.IntroductionLetEbearealBanachspace,notnecesarilyreflexive.LetΦ,Ψ:E→]-∞,∞]betwolowersemicontinuousconvexfunctions.Wedenote... 相似文献
10.
Zhao Jing Meng Fanwei Liu Zhenbin 《Annals of Differential Equations》2005,21(2):229-236
In this paper, by means of auxiliary functions and inequalities, we obtain some sufficient conditions of second order nonhomogeneous delay differential equation belonging to the L.S. or L.S. ∩L.C.. 相似文献
11.
Practical stability in terms of two measures for difference equations is discussed by using the Lyapunov function and a new comparison theorem. 相似文献
12.
In this article,first,a sufficient condition for a starlike mapping of order α f(x) defined on the unit ball in a complex Banach space is given. Second,the sharp estimate of the third homogeneous expan... 相似文献
13.
FU WANTAO 《数学年刊B辑(英文版)》1994,(2)
ONTHETHEOREMOFARROW-BARANKIN-BLACKWELLFORWEAKIYCOMPACTCONVEXSET¥FUWANTAOAbstract:ThispaperstudiestheknowndensitytheoremofArro... 相似文献
14.
The eigenvalue problem of the transport operator for a general bounded convex body V is studied mathematically. Where either V or the eigenfunction of the operator is not necessarily of spherical symmetry.It is shown that the spectrum of the operator consists of pure eigenvalues, possibly plusthe point of negative infinity.There is a countable infinity of real eigenvalues accumulating at minus infinity. Each eigenvalue, especially one in the left half-plane, is of index one, There is no complex (non-real) eigenvalue in the right half-plane Re λ>Σ. The solution of the corresponding initial-value problem is also discussed. 相似文献
15.
We give some new elimination conditions for permutation flow-shop problem and prove that thereis one among them equivalent to Szwarc's elimination condition.Next we propose some new lowerbounds for a branch-and-bound method and design an algorithm.Computational results indicate thatthe proposed algorithm is more efficient than those we found in literature. 相似文献
16.
胡迪鹤 《数学物理学报(B辑英文版)》2005,25(1):23-29
This paper is a continuation of [8]. In Section 1, three kinds of communication are introdnced for two states and the relations among them are investigated. In Section 2, two kinds of period of a state are introdnced and it is obtained that the period is a “class property” ,i.e. two states x and y belong to same class implies the period of x is equal to the period of y. 相似文献
17.
F. Jeeawock-Zedek 《分析论及其应用》1994,(2)
The aim of this paper is to give upper bounds of the norm of the operator and associated error for aLagrange interpolation problem by C~1 quadratic splines. The domain is rectangular and the type-2triangulation is non--uniform. Moreover the location of data points allows a very simple compation of theinterpolant. 相似文献
18.
ON THE EMPTY CONVEX PARTITION OF A FINITE SET IN THE PLANE 总被引:2,自引:0,他引:2
The authors discuss the partition of a finite set of points in the plane into empty convex polygons, and improve some upper bound and lower bound in the related enumeration problems. 相似文献
19.
In this paper we obtain new criteria for the positive equilibrium K of thenonautonomous Hutchinson's equationN'(t) = r(t)N(t)[1-[N(t-τ)]/K], t≥0,to be uniformly stable. Examples illustrating the significance of the results arealso given. 相似文献
20.
This paper proves that any rotationally symmetric translating soliton of mean curvature flow in R3 is strictly convex if it is not a plane and it intersects its symmetric axis at one point. The authors also study the symmetry of any translating soliton of mean curvature flow in Rn. 相似文献