用低频扭摆的方法，系统地研究了能够较有把握地观测到在AI-0.5%Cu合金中所出现的反常位错內耗的实验程序。 结果指出，把试{羊在拉力试验机上預先拉伸到某一适当的形变量后，立即测量它在某一适当溫度下时效的过程中的內耗，可以在內耗一时效时间曲线上观察到一个表现反常振幅效应(郎內耗一振幅曲线上出现一个峯值)的时效內耗峑。用经过充分时效而內耗已经达到稳定值的试样，逐渐增加振幅，测量內耗，也可以观察到一个应变振幅內耗家（当內耗表示为应变振幅的函数时）。此外，用一定的应变振幅在较高溫度下，测量经过充分时效的试样的內耗吋，也可以观察到一个表现反常振幅效应的溫度內耗峯（当內耗表示为溫度的函数时）。这些实验结果肯定地指出，在一定测量溫度下的振幅內耗峯和表现反常振幅效应的溫度內耗峯是存在的。为了找出以前在Al-0.5%Cu中所观察到的反常內耗现象重复性不好的原因，系统地研究了测量內耗所用的应变振幅对于出现振幅內耗峯的影响以及預形变量对于出现时效內耗峯和溫度內耗峯的影响。对于出现反常內耗现象的实验条件进行了分析。所观察到的关于反常內耗现象的实验结果，都可用位错拖着溶质原子气团运动的模型来作定性的解释。具体的模型和理论分析将另行报导。

用低频扭摆进一步研究了在AI-0.5%Cu合金中观察到反常位错内耗的条件。结果指出，对于完个退火的试柞来说，需要有适当的冶加工量，但是对于高溫淬火试佯则不需要洽加工。用位错气团模型定性地解释了过去所观测到的表现反常振幅效应的时效內耗察和溫度內耗翟；同吋指出，简单的气团模型在作定量的解释吋，遇到了下述的困难：(i)在测量內耗所用的交交应力的作用下，位错线所能够拖萧气团移动的距离太短。(ii)为了气团能够被位错拖看移动，组成气团的溶质原子必须具有比通常大很多个数量级的扩散系数，(iii)根据气团模型，从理论上计算出来的使位错拖着气团以临界速度而移动吋，所需的临界应力比观测值大几百倍。提出了溶质原子沿着位错弯结而扩妝的气团模型，这个改进模型能够初步解决上述困准，井能定性地解释所观测的结果。这个泛型所依据的基本假设是，要观测到反常內耗现象，位错线上必须具有一定数日的弯结。要得到这种弯结，可以对于退火试作进行适量的冷加工，或者把试样从高溫淬火。带着弯结的位错线能够通过弯结的沿边运动而实现垂直于位错线方向的移动。可以假定，气团只在弯结两端的直位错殴灶形成，在弯结本身上并不形成气团。在弯结的沿边振动的过程中，聚集在弯结两端的溶质原了可以沿着位错管道进行来回的短程扩散。已旬沿着位错管道的扩散具有比在正常晶体点阵中扩散吋大得多的扩散系数。

Reconstruction and displacement of crystal structure and motion of the phase interface induces dissipation of energy, and latent heat appears during a first-order phase transition (FOPT) in solids. In this series of investigations, we first express the energy dissipation as a function of four physical parameters. Since there are more unknowns than the number of equations, we introduce four more equations describing the dynamics of the system on which internal friction (IF, the dissipation of vibration energy) measurements are conducted. Via IF measurements during FOPT, we can then calculate the relevant four parameters and hence the dissipation function. We have completed the first step in establishing a phenomenological theory to describe FOPT in solids.

In order to apply the concept of the dissipation function during the first-order phase transition (FOPT) in solids, we measured the internal friction Q-1 and shear modulus μ for a range of frequencies of polycrystalline ceramics VO2 as the sample passed through a FOPT across the temperature range of 300-0420K. The experiment was repeated for different temperature variation rate T. We have found that for each frequency, a maximum of Q-1 and a minimum of μ occurred at the same temperature Tp when T was kept constant. The numerical values of the dissipation function AGR plus other FOPT parameters have been deduced using Q-1 data. The general trend of AGR-T and other results are found to be consistent with known physical aspects.

We apply renormalization group theory directly to the first-order phase transition of the large-N model driven linearly by an external magnetic field H--H t, where H is the sweeping rate. Novel dynamic, scaling forms for the magnetization., the structure factor, and the area of hysteresis loop are M (H,t,T)=f(H1/2t, H(d-2)/4T), C(k,H,t,T)=H-d/4f1(H-1/4k, H1/2t, H(d-2)/4T), and A=H1/2g(H(d-2)/4T), respectively, where T is the temperature of the system, d the spatial dimensionality, k the wave number, and f, f1, and g scaling functions. These results show that the rate of the external driving field can serve as a scaling parameter to study hysteresis.