We develop a simple yet comprehensive nonlinear model to describe relaxation phenomena in amorphous glass-formers near the glass transition temperature. The model is based on the two-state, two-(time)scale (TS2) framework, and describes the isothermal relaxation of specific volume, enthalpy, or shear stress via a simple first-order nonlinear differential equation (the Trachenko-Zaccone [TZ] equation) for local cooperative events. These nonlinear dynamics of cooperatively rearranging regions (CRR) naturally arise from the TS2 framework. We demonstrate that the solutions of the TZ equation comprehensively encompass the Debye exponential relaxation, the Kohlrausch-Williams-Watts (KWW) stretched and compressed relaxations, and the Guiu-Pratt logarithmic relaxation. Furthermore, for the case of stress relaxation modeling, our model recovers, as one of its limits, the Eyring law for plastic flow, where the Eyring activation volume is related to thermodynamic parameters of the material. Using the example of polystyrene (PS), we demonstrate how our model successfully describes the Kovacs "asymmetry of approach" specific volume and enthalpy experiments, as well as the stress relaxation. Other potential applications of the model, including the dielectric relaxation, are also discussed. The presented approach disentangles the physical origins of different relaxation laws within a single general framework based on the underlying physics.
Compressed correlation functions and fast aging dynamics in metallic glasses
我们提出的X射线光子相关光谱测量的原子动力学在Zr 67 Ni 33金属玻璃，远低于其玻璃化转变温度。我们发现密度涨落的衰减可以用压缩的、比指数快的关联函数来描述，这种关联函数可以用著名的Kohlrausch-Williams-Watts函数来模拟，其形状指数β大于1。这个参数还被发现是独立的等待时间和波矢量，导致的可能性，重新调整所有的关联函数到一个单一的主曲线。在玻璃态的动力学的特征还在于不同的老化制度，坚持在深玻璃态。这些功能似乎是普遍的金属玻璃，并建议一个非扩散性质的动态。这种普遍性是支持的可能性，描述的结构弛豫时间与等待时间的快速增加，使用一个独特的模型函数，独立的系统的微观细节。
Shear Unfreezing Explains Yielding, Plasticity and Neck Initiation of Glassy Polymers
School of Physics, Beihang University（北京航空航天大学物理学院）；Wenzhou Institute, University of Chinese Academy of Sciences（中国科学院大学温州研究院）；Peng Huanwu Collaborative Center for Research and Education, Beihang University（北京航空航天大学彭恒武科教协同中心）
The microscopic origins of stretched exponential relaxation in two model glass-forming liquids as probed by simulations in the isoconfigurational ensemble
Continuum modeling of Soft Glassy Materials under shear
Università di Roma “Tor Vergata”（罗马托尔维尔加塔大学）；ENSL, CNRS, Laboratoire de physique（里昂高等师范学校，法国国家科学研究中心，物理实验室）；Univ. de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière（里昂大学，克莱贝尔·伯纳德里昂第一大学，法国国家科学研究中心，光物质研究所）；Institut Universitaire de France (IUF)（法兰西学院）；Eindhoven University of Technology（埃因霍温理工大学）；CNR-IAC（意大利国家研究委员会应用化学研究所）
