Huanhuan HuoHaiyan LiuXinzhong BaoWei Cui2025-05-222025-05-222022jz000178-0060https://tustorage.ulb.tu-darmstadt.de/handle/tustorage/36534600Eco-Efficiency Assessment of Beijing-Tianjin-Hebei Urban Agglomeration Based on Emergy Analysis and Two-Layer System DynamicsArticlehttps://doi.org/10.3390/systems10030061