def METHOD_NAME(self, s):
    """
    Notes
    -----
    计算一组不同物质的偏心因子
    """
    n = len(s) # 物质的个数
    index = np.zeros(n, dtype=np.int_)
    for i, name in enumerate(s):
        index[i] = self.substance[name]
    c = 3.0/7.0
    pc = self.cproperty[index, 1]*1.45037737730e+2 # 临界压强, MPa to PISA
    Tc = self.cproperty[index, 0] # 临界温度
    Tb = self.cproperty[index, 3] # 沸点温度
    Tr = Tc/Tb
    omega = c*np.log(pc/14.695)/(Tr-1) - 1
    return omega