This study proposes a new method of symmetrical stirring using an anchor paddle to improve the heating uniformity of liquids. To simulate the complex physical process of microwave heating a fluid while stirring it, the finite element method (FEM) and the arbitrary Lagrangian–Eulerian (ALE) method were utilised to model the interactions between electromagnetics, heat transfer, and fluid flow. The temperature coefficient of variation (COV) of the water when subjected to microwave heating and the symmetrical stirring paddle decreased by an 11.2–81.5% compared to that achieved by the traditional rotating turntable method, and it further decreased as the stirring frequency increased. This implies that the stirring method performed more favourably than the rotation method in improving the uniformity of the microwave heating. The distributions of the three physical fields indicated that symmetrical stirring enhanced the axial fluid flow and heat transfer, reducing the large intrinsic temperature difference along the vertical direction. Furthermore, the computation results were validated experimentally, showing that the proposed method is sufficiently accurate for evaluating the uniformity of microwave heating.

We collect the yields of charged pions ( ${\pi }^{-}$ and ${\pi }^{+}$ ), charged kaons ( $K^{-}$ and $K^{+}$ ), anti-protons ( $\overline{p}$ ), and protons (p) produced in mid-rapidity interval (in most cases) in central gold–gold (Au–Au), central lead–lead (Pb–Pb), and inelastic or non-single-diffractive proton–proton ( $pp$ ) collisions at different collision energies. The chemical potentials of light particles and quarks are extracted from the yield ratios, ${\pi }^{-}/{\pi }^{+}$ , $K^{-}/K^{+}$ , and $\overline{p}/p$ , of antiparticles to particles over an energy range from a few GeV to above 10 TeV. At a few GeV (∼4 GeV), the chemical potentials show, and the yield ratios do not show, different trends comparing with those at other energies, although the limiting values of the chemical potentials and the yield ratios at very high energy are 0 and 1, respectively.

To present a prediction of the multi-particle production and multi-fragment emission in electron-nucleus ($eA$) collisions at the forthcoming Electron-Ion Collider (EIC), a simple hybrid model which is based on the multi-source thermal model and the ideal gas model is proposed in this article. According to the hybrid model, some statistical laws such as the two-component Erlang distribution and others are presented, which means a two-source production. These statistical laws are hopeful to describe the bulk properties of multiple particles produced in the scattering of electron-nucleon ($eN$) and multiple fragments emitted in the fragmentation of excited residual nucleus. Although both the scattering and fragmentation can occur in $eA$ collisions at the EIC, their two-sources are different. In $eN$ scattering, the multiple particles come from the soft excitation and hard scattering processes respectively, which are classified as two different types of events. In nuclear fragmentation, the multiple fragments come from the cold and hot sources which exist in the same excited nucleus.