Extracting chemical potentials of quarks from ratios of negatively/positively charged particles in high-energy collisionsFu-Hu Liu, Tian Tian, Hong Zhao and Bao-Chun LiEur. Phys. J. A, 50 3 (2014) 62DOI: https://doi.org/10.1140/epja/i2014-14062-5