The incompressibility of the fluid is determined by introduction of a so-called particle density number. 流体的不可压缩性是通过引人粒子数密度概念实现的。
In strong magnetic fields, Proton density increases with the increasing of total baryon densities, while neutron number density decreases. 随着总粒子密度的增加质子粒子数密度增加，中子粒子数密度减小。
