Prediction of the Long-Term Performance Based on the Seepage-Stress-Damage Coupling Theory: A Case in South-to-North Water Diversion Project in China

The South-to-North Water Diversion Project has been in operation since 2014, directly benefiting more than 79 million people in China. Thus, its service life and long-term performance have gained much attention from scholars. To predict its life and performance, this study used the seepage/stress-damage coupling method. In addition, a seepage/stress-damage coupling theory was proposed and a finite element model of a deep excavated canal in the Xichuan Section of the South-to-North Water Diversion Project was established. The results showed that this canal subsided greatly in the first two years of operation, which can be confirmed by the monitoring data. It is predicted that, after 50 years of normal operation, the canal damage may start and spread from the water level, and reach 37.6%, but such damage will not affect its normal water delivery function. The purpose of this study is to provide guidance for the safe operation of the project.

A Copper Foil Electromagnetic Coupler and Its Wireless Power Transfer System without Compensation

This paper proposes a copper foil electromagnetic coupler integrating inductance and capacitance and its wireless power transfer (WPT) system without additional compensation structure. Firstly, the equivalent circuit model of the integrated electromagnetic coupler is established, and the circuit model is simplified based on the circuit theory and mutual inductance coupling theory. The self-compensating characteristics of the coupler are utilized to analyze and design the relation between electrical parameters of the system, and the basic conditions of full resonance working of the system are given. The system’s performance is verified by simulation.

Dynamic heterogeneity in active glass-forming liquids is qualitatively different compared to its equilibrium behaviour

Activity driven glassy dynamics is ubiquitous in collective cell migration,intracellular transport, dynamics in bacterial and ants colonies as well as artificially driven synthetic systems such as vibrated granular materials, etc. Active glasses are hitherto assumed to be qualitatively similar to their equilibrium counterparts at a suitably defined effective temperature, ff. Combining large-scale simulations with analytical mode-coupling theory for such systems, we show that, in fact, an active glass is qualitatively different from an equilibrium glassy system. Although the relaxation dynamics can be similar to an equilibrium system at a ff, effects of activity on the dynamic heterogeneity (DH), which has emerged as a cornerstone of glassy dynamics, is quite nontrivial and complex. In particular, active glasses show dramatic growth of DH, and systems with similar relaxation time and ff can have widely varying DH. Comparison of our non-equilibrium extended mode-coupling theory for such systems with simulation results show that the theory captures the basic characteristics of such systems. Our study raises fundamental questions on the supposedly central role of DH in controlling the relaxation dynamics in a glassy system and can have important implications even for the equilibrium glassy dynamics.