Γ-环和广义Γ-环的强幂零性

In this paper, we study the strongly nilpotency of Γ-rings and generalized Γ-rings.(Ⅰ) With what conditions is a strongly nil subring of Γ-rings strongly nilpotent?(Ⅱ) With what conditions is a nil subring of Γ-rings strongly nilpotent?For(Ⅰ), the condition is one of the following conditions:(1) ascending chain condition on the- strongly nilpotent subrings.(2) Noether's condition.(3) Goldie's condition.(4) ascending chain condition on right annihilators and on left annihilators. For(Ⅱ), the conditions is (2) or (3). In order that the above results may contain the corresponding results of associative rings, a new concept, generalized Γ-ring is introduced, so that any associative ring is naturally explained as a generalized Γ-ring. It is proved that the above results are valid in generalized Γ-rings. Thence the well-known results of associative rings are special cases in generalized Γ-rings.     

A NEW CLASS OF BILEVEL GENERALIZED MIXED EQUILIBRIUM PROBLEMS IN BANACH SPACES

A new class of bilevel generalized mixed equilibrium problems involving setvalued mappings is introduced and studied in a real Banach space. By using the auxiliary principle technique, new iterative algorithms for solving the generalized mixed equilibrium problems and bilevel generalized mixed equilibrium problems involving set-valued mappings are suggested and analyzed. Existence of solutions and strong convergence of the iterative sequences generated by the algorithms are proved under quite mild conditions. The behavior of the solution set of the generalized mixed equilibrium problems and bilevel generalized mixed equilibrium problems is also discussed. These results are new and generalize some recent results in this field.     

Generalized Einstein tensor for a Weyl manifold and its applications

It is well known that the Einstein tensor G for a Riemannian manifold defined by G βα = R βα 1/2 Rδβα , R βα = g βγ R γα where R γα and R are respectively the Ricci tensor and the scalar curvature of the manifold, plays an important part in Einstein's theory of gravitation as well as in proving some theorems in Riemannian geometry. In this work, we first obtain the generalized Einstein tensor for a Weyl manifold. Then, after studying some properties of generalized Einstein tensor, we prove that the conformal invariance of the generalized Einstein tensor implies the conformal invariance of the curvature tensor of the Weyl manifold and conversely. Moreover, we show that such Weyl manifolds admit a one-parameter family of hypersurfaces the orthogonal trajectories of which are geodesics. Finally, a necessary and sufficient condition in order that the generalized circles of a Weyl manifold be preserved by a conformal mapping is stated in terms of generalized Einstein tensors at corresponding points.     

Boundary value problems of discrete generalized Emden-Fowler equation

By using the critical point theory, some sufficient conditions for the existence of the solutions to the boundary value problems of a discrete generalized Emden-Fowler equation are obtained. In a special case, a sharp condition is obtained for the existence of the boundary value problems of the above equation. For a linear case, by the discrete variational theory, a necessary and sufficient condition for the existence, uniqueness and multiplicity of the solutions is also established.     

ISOMETRIC OPERATORS ON П_K SPACES

The authors obtain all generalized triangle models of U-dilation of an isometric operator on П_K and prove that an isometric operator on Hr has Wold decomposition and the unilateral parts of generalized Wold decomposition for an isometric operator on П_K are uniquely determined up to unitary equivalence. Then a necessary and sufficient condition is got under which an isometric operator on IIк has a regular Wold decomposition.     

一般Volterra-Stieltjes微积分方程的比较定理

In this paper, A. B, Mingarelli‘s result is generalized to General Volterra-Stieltjes Integro-differential Equations. Comparison theorem and equivalence condition of non-oscillation are obtained.Clasical Sturm comparison theorem and some conclusions are generalized.     

COMPONENTWISE CONDITION NUMBERS FOR GENERALIZED MATRIX INVERSION AND LINEAR LEAST SQUARES

We present componentwise condition numbers for the problems of Moore-Penrose generalized matrix inversion and linear least squares. Also, the condition numbers for these condition numbers are given.     

Generalized K-T conditions and penalty functions for quasidifferentiable programming

In this paper,a quasidifferentiable programming problem with inequality constraintsis considered. First,a general form of optimality conditions for this problem is glven,which contains the results of Luderer,Kuntz and Scholtes. Next,a new generalized K-T condition is derived. The new optimality condition doesn‘t use Luderer‘s regularity assumption and ita Lagrangian multipliers don‘t depend on the particular elements in the superdifferentials of the object function and constraint functions, Finally,a penalty function for the prohlem is studied. Sufficient conditions of the penalty function attaining a global minimum are obtained.     

Heisenberg群上一类半线性方程全局解的存在性

Based on the concepts of a generalized critical point and the corresponding generalized P.S. condition introduced by Duong Minh Duc [1], we have proved a new Z2 index theorem and get a result on multiplicity of generalized critical points. Using the result and a quite standard variational method, it is found that the equation -ΔH^nu=|u|^p-1u,x∈H^n has infinite positive solutions. Our approach can also be applied to study more general nonlinear problems.     

GENERALIZED SIMULTANEOUS CHEBYSHEV APPROXIMATION

In this note,we develop,without assuming the Haar condition,a generalized simultaneousChebyshev approximation theory which is similar to the classical Chebyshev theory and con-rains it as a special case.Our results also contain those in[1]and[3]as a special case,and thetwo conjectures proposed by C.B.Dunham in[2]are proved to be true in the case of simulta-neous approximation.