论文标题
通过研究模型系统了解温度调制的量热法
Understanding temperature modulated calorimetry through studies of a model system
论文作者
论文摘要
温度调制的量热法被广泛使用，但仍提出一些基本问题。在本文中，我们将模型系统作为测试样本研究，以解决其中的一些样本。该模型具有非平凡的放松时间。我们研究温度调制的量热法在恒定平均温度下的量热法，以精确依赖频率的热容量的含义，与熵产生的关系以及这种测量方法如何观察到玻璃状样品的老化，从而导致时间依赖性热容量。 KOVACS效应对过平衡系统的研究表明，温度调节量热法如何有助于理解这种记忆效应。然后，我们比较标准扫描量热法和温度调节量热法的测量值，并显示两种方法是互补的，因为它们不观察到相同的特征。虽然它可以探测系统中能量传输的时间尺度，但即使在低频温度调制的量热法的极限也不会探测一些可以通过扫描量热法测量的弛豫现象，如用玻璃的实验所暗示的那样。
Temperature Modulated calorimetry is widely used but still raises some fundamental questions. In this paper we study a model system as a test sample to address some of them. The model has a nontrivial spectrum of relaxation times. We investigate temperature modulated calorimetry at constant average temperature to precise the meaning of the frequency-dependent heat capacity, its relation with entropy production, and how such measurements can observe the aging of a glassy sample leading to a time-dependent heat capacity. The study of the Kovacs effect for an out-of-equilibrium system shows how temperature modulated calorimetry could contribute to the understanding of this memory effect. Then we compare measurements of standard scanning calorimetry and temperature-modulated calorimetry and show how the two methods are complementary because they do not observe the same features. While it can probe the time scales of energy transfers in a system, even in the limit of low frequency temperature modulated calorimetry does not probe some relaxation phenomena which can be measured by scanning calorimetry, as suggested by experiments with glasses.
