Jieshuang Wang obtained his PhD in 2018 in Nanjing University. After PhD he moved to TDLI as a postdoc fellow. In 2022-2024 he was awarded as an Alexander von Humboldt fellow and worked in Max-Planck institute for nuclear physics in Germany. Since June 2024, he worked as a postdoc in Max-Planck institute for plasma physics. His main research interest are high-energy astrophysics related to compact stars, including accreting black holes, neutron star binaries and magnetars. He study the dynamics and particle acceleration and multi-messenger radiation with both analytical modeling and relativistic magnetohydrodynamic and particle-in-cell simulations. He has more than 50 publications (19 first-author papers) and 1900+ citations (h-index:21)The origin of cosmic rays (CRs) remains an open question. The CR spectrum is characterized by two significant breaks: the knee at ~3 PeV (1e15 eV) and the ankle at ~3 EeV (1e18 eV). It is widely accepted that ultra-high-energy cosmic rays (UHECRs) above the ankle originate from extragalactic sources, with the transition energy between galactic and extragalactic components lying between the knee and the ankle. Recent observations suggest that the proton cutoff for UHECRs occurs at a few EeV, while higher energy CRs consist of higher mass atomic nuclei. Centaurus A, a nearby radio galaxy, is considered a major source of UHECR anisotropies, supporting the idea that radio galaxies (active galactic nuclei with kpc-scale jets) are sources of UHECRs.In this talk, I will present our analytical and numerical study using relativistic magnetohydrodynamic and particle-in-cell (RMHD-PIC) simulations of astrophysical jets. This study provides a self-consistent framework for understanding multi-wavelength observations and the acceleration of UHECRs. Furthermore, we found that galactic ultra-luminous X-ray sources (ULXs) can contribute to the CR flux between the knee and the ankle. Lastly, I will introduce future possibilities for identifying CR sources through multi-messenger observations and testing the AGN and ULX hypotheses as CR sources above the knee.