China Ctr Adv Sci & Technol, World Lab, Beijing 100080, Peoples R China
; Acad Sinica, Inst High Energy Phys, Beijing 100039, Peoples R China
; Nanjing Normal Univ, Dept Phys, Nanjing 210024, Peoples R China
; Nankai Univ, Dept Phys, Tianjin 300071, Peoples R China
The previous treatments for strange quark matter in the quark mass-density-dependent model have unreasonable vacuum limits. We provide a method to obtain the quark mass parametrizations and give a self-consistent thermodynamic treatment which includes the MIT bag model as an extreme. In this treatment, strange quark matter in bulk still has the possibility of absolute stability. However, the behavior of the sound velocity is opposite to previous findings.