  Interesting chemically peculiar field stars may reflect their stellar
evolution history and their possible origin in a different environment from
where they are found now, which is one of the most important research fields in
Galactic archaeology. To explore this further, we have used the CN-CH bands
around 4000 A to identify N-rich metal-poor field stars in LAMOST DR3. Here we
expand our N-rich metal-poor field star sample to ~100 stars in LAMOST DR5,
where 53 of them are newly found in this work. We investigate light elements of
the common stars between our sample and APOGEE DR14. While Mg, Al, and Si
abundances generally agree with the hypothesis that N-rich metal-poor field
stars come from enriched populations in globular clusters, it is still
inconclusive for C, N, and O. After integrating the orbits of our N-rich field
stars and a control sample of normal metal-poor field stars, we find that
N-rich field stars have different orbital parameter distributions compared to
the control sample, specifically, apocentric distances, maximum vertical
amplitude (Zmax), orbital energy, and z direction angular momentum (Lz). The
orbital parameters of N-rich field stars indicate that most of them are
inner-halo stars. The kinematics of N-rich field stars support their possible
GC origin. The spatial and velocity distributions of our bona fide N-rich field
star sample are important observational evidence to constrain simulations of
the origin of these interesting objects.
