(Abridged) We performed the spectroscopic observations of 11 confirmed GCs in
M31 with the Xinglong 2.16m telescope and we mainly focus on the fits method
and the metallicity gradient for the M31 GC sample. We analyzed and discussed
more about the dynamics, metallicity and age, and their distributions as well
as the relationships between these parameters. Eight more confirmed GCs in the
halo of M31 were observed, most of which lack the spectroscopic information
before. These star clusters are located far from the galactic center at a
projected radius of ~14 to ~117 kpc. The Lick absorption-line indices and the
radial velocities have been measured and ages, metallicities [Fe/H] and
alpha-element [alpha/Fe] have also been fitted by comparing the observed
spectral feature indices and Thomas et al.SSP model. Our results show that most
of the star clusters of our sample are older than 10 Gyr except B290 ~5.5 Gyr,
and most of them are metal-poor with the metallicity [Fe/H]<-1, suggesting that
these clusters were born at the early stage of the galaxy's formation. We find
that the metallicity gradient for the outer halo clusters with r_p>25 kpc may
not exist with a slope of -0.005+-0.005 dex kpc^-1. We also find that the
metallicity is not a function of age for the GCs with age < 7 Gyr while for the
old GCs with age >7 Gyr there seems to be a trend that the older ones have
lower metallicity. Besides, We plot metallicity distributions with the largest
sample of M31 GCs so far and it shows the bimodality is not significant and the
number of the metal-poor and metal-rich groups becomes comparable. The spatial
distributions shows that the metal-rich group is more centrally concentrated
while the metal-poor group is occupy a more extended halo and the young
population is centrally concentrated while the old population is more extended
spatially to the outer halo.Comment: 17 pages, 10 figures and 6 tables. Accepted for publication in RA