5 papers
A Magnetic Torsional Pendulum for Exploring Forced Resonance, Parametric Resonance, and Parametric Amplification
Wenqing Xie, Jiahao Wu, Yujun Shi
We present a magnetic torsional pendulum that provides a unified experimental platform for investigating forced resonance, parametric resonance, and degenerate parametric amplifica…
Revisiting Koehler's experiment of measuring the ratio of the specific heats of air by self-sustained oscillations
Yujun Shi, Xiaoting Fen
We revisit Koehler's experiment, a clever modification of Ruchardt's experiment designed to measure the ratio of specific heats of gas. However, the lengthy and dense analysis shar…
Recurrence in a periodically driven and weakly damped Fermi-Pasta-Ulam-Tsingou chain
Yujun Shi, Haijiang Ren
We report numerical evidence of Fermi-Pasta-Ulam-Tsingou (FPUT)-like recurrence in weakly damped, periodically driven alpha-FPUT chains. In narrow regions of driving amplitude and…
Geometric invariance from outer surfaces: Laplace-governed magnetization in the high-permeability limit
Yujun Shi
The magnetization of bodies in static fields is a textbook topic in electrodynamics, governed by Laplace equations with interface continuity (transmission) conditions. In the infin…
Discretely structured magnetic flux concentrators
Yujun Shi, Xiaoting Feng
Conventional magnetic flux concentrators (MFCs) are typically designed with solid structures, which may not be optimal for applications requiring lightweight design or material eff…