作者：Zhenghua Luo , Bentuo Zheng 来源：[J].Studia Mathematica(IF 0.549), 2020, Vol.250, pp.19-34 摘要：A normed space $X$ is said to have the ball-covering property (BCP,for short) if its unit sphere can be covered by the union of countablymany closed balls not containing the origin. Let $(\varOmega, \varSigma, \mu)$ bea separable measure space and $X$ be a normed space. We show t...
 作者：Lixin Cheng , Qingjin Cheng , Zhenghua Luo 来源：[J].Studia Mathematica(IF 0.549), 2010, Vol.201, pp.155-166 摘要：We show several characterizations of weakly compact sets in Banach spaces. Given a bounded closed convex set $C$ of a Banach space $X$, the following statements are equivalent: (i) $C$ is weakly compact; (ii) $C$ can be affinely uniformly embedded into a reflexive Banach spa...