We report the realization of acoustic collimating beams by a two-dimensional phononic crystal, which has a negative effective refractive index of small magnitude. The radiation far field of a point source through the phononic crystal with a divergence angle of about 5° is obtained. The measured intensity field distribution in experiment further confirms this collimating property.
A hybrid star with a pure quark core, a hadron crust and a mixed phase between the two is considered. The relativistic mean field model for hadron matter and the effective mass bag model for quark matter are used to construct the equation of state for hybrid stars. The influences of medium effects that are parameterized by the strong coupling constant have been discussed on the configuration of rotating stars. The strong coupling constant is a prominent factor that influences the properties of rotating hybrid stars.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.