Critical Phenomena Near the Superfluid Transition of 4He

液氦超流（SF）相变的研究 4：1）研究含氦气凝胶作为杂质，测量 热膨胀和导热性。 数据 浓度和压力依赖性将阐明 纯的和不纯的相变之间的关系 系统. 2)研究二次声波在sf附近的传播 超流和正常流体速度下的转变 场，以测试最近的理论的正确性。 %%% 量子力学是所有物质行为的基础和支配。 液氦几乎是独一无二的， 作为宏观尺度上的量子力学系统。 研究 例如，这里提出的这些建议可望促进其 理解量子物理学，以及相变， 多孔材料的特殊性质。

Investigations of the superfluid (sf) transition in liquid helium 4: 1) Study helium containing aerogels as an impurity, measuring the thermal expansion and thermal conductivity. Data on the concentration and pressure dependences will illuminate the relationship between the phase transitions in the pure and impure systems. 2) Study the propagation of second sound near the sf transition in the presence of superfluid and normal-fluid velocity fields, to test the correctness of a recent theory. %%% Quantum mechanics underlies and governs the behavior of all matter. Liquid helium is almost unique in being a substance which behaves as a quantum mechanical system on a macroscopic scale. Studies such as are here proposed can be expected to advance their understanding of quantum physics, as well as phase transitions and the special properties of porous materials.