Near convexity,near smoothness and approximative compactness of half spaces in Banach spaces

The authors discuss the dual relation of nearly very convexity and property WS. By two kinds of near convexities and two kinds of near smoothness, the authors prove a series of characterizations such that every half-space in Banach space X and every weak* half-space in the dual space X* are approximatively weakly compact and approximatively compact. They show a sufficient condition such that a Banach space X is a Asplund space. Using upper semi-continuity of duality mapping, the authors also give two characterizations of property WS and property S.     

Property (w) and perturbations II

This note is a continuation of a previous article [P. Aiena, M.T. Biondi, Property (w) and perturbations, J. Math. Anal. Appl. 336 (2007) 683-692] concerning the stability of property (w), a variant of Weyl's theorem, for a bounded operator T acting on a Banach space, under finite-dimensional perturbations K commuting with T. A counterexample shows that property (w) in general is not preserved under finite-dimensional perturbations commuting with T, also under the assumption that T is a-isoloid.     

Banach Spaces with Property (M) and their Szlenk Indices

We show that a separable Banach space with property (M*) has a Szlenk index equal to ω₀, and a norm with an optimal modulus of asymptotic uniform smoothness. From this we derive a condition on the Szlenk functions of the space and its dual which characterizes embeddability into c ₀ or an ℓ _p -sum of finite dimensional spaces. We also prove that two Lipschitz-isomorphic Orlicz sequence spaces contain the same ℓ _p -spaces.      

闭孔泡沫塑料结构与性能研究进展

综述了近年来对闭孔泡沫塑料,主要是发泡聚烯烃的结构与性能关系研究的进展。总结了有关泡沫塑料的常见结构模型以及性能结构关系的解析式表达,并介绍了常见表征泡沫塑料结构、性能的方法以及近年来出现的新的表征手段。文章讨论了近年来研究塑料泡沫结构与性能尤其是力学性能之间关系的新结果、新进展,并对研究进行了展望。     

Spaces of Operators,the ψ-Daugavet Property,and Numerical Indices

Suppose ψ : [0, ∞) → [1, ∞) is a strictly increasing function. A Banach space X is said to have the ψ-Daugavet Property if the inequality holds for every compact operator T : X → X. We show that, if 1 < p < ∞ and K(ℓ_p)↪ X ↪ B(ℓ_p), then X has the ψ-Daugavet Property with (here and c_p is an absolute constant). We also prove that a C^*-algebra A is commutative if and only if for any . Together, these results allow us to distinguish between some types of von Neumann algebras by considering spaces of operators on them. The author was supported in part by the NSF grant DMS-9970369.     

葫芦脲的研究进展

葫芦脲(CB[n])及其衍生物是由n个苷脲单元连接成的穴状分子,因其结构特殊,受到广泛的关注与研究。本文综述了CB[n]的性质、合成以及近年来CB[n]在分子开关、催化剂、药物载体等方面的研究进展。     

聚对苯二甲酰对苯二胺对尼龙-6共混改性的影响

<正> 聚对苯二甲酰对苯二胺(PPTA)是一种棒状的刚性高分子,由它的液晶溶液可制得高强度、高模量、耐高温纤维,这种纤维可作为增强剂以制备高性能的复合材料。若将刚性链高分子以近于分子水平分散到柔性链高分子中,可期望得到性能良好的分子复合材     

Aspects of the Qualitative Theory of Suspended Foliations

We proved that the set of suspended foliations of a compact manifold M is open in the space of foliations with C r -topology. Relation between sets of suspended foliations with Hausdorff and non-Hausdorff graphs are investigated from topological and set-theoretical points of view. Continuum set of pairwise non-isomorphic C X -diffeomorphisms of 1-dimensional manifold with special properties is constructed and used essentially.     

应用电化学方法对α和β_i(i=1,2,3)-K_5SiFe(OH_2)W_(11)O_(39)·nH_2O氧化还原性质的研究

本文系统地研究了α和βi- K5Si Fe( OH2 ) W11O39· n H2 O( i=1,2 ,3)的氧化还原性质 ,通过导数脉冲伏安法、常规脉冲伏安法及循环伏安法确定了其氧化还原机理 ,并比较了其氧化还原性质的强弱。     

茂金属乙丙弹性体技术进展

论述了茂金属乙丙弹性体的合成,表征、反应机理,工业化进程化以及工业化应用,着重介绍了茂金属催化体系和茂金属乙丙弹性体的结构和性能。