论文标题
关于超流氦的喷泉效应
On the Fountain Effect in Superfluid Helium
论文作者
论文摘要
分析了超级流体氦气中温度较小的喷泉压力的起源。基于Tisza（1938）基于基态玻色子的不同分数引起的渗透压解释是理想的解决方案，并显示出通过数量级或更多的数量级高估了喷泉压力。实验确认的H. London（1939）的热力学表达，其中压力的温度导数等于每单位体积的熵，被证明等于化学势的平等，而不是化学势除以温度。前者导致在恒定熵下的能量最小化，而后者是由于最大化熵而导致的。可以得出结论，喷泉效应中的超流动流是由机械而非统计力驱动的。这一新原则似乎是超流体和超导体流动的一般定律。
The origin of the fountain pressure that arises from a small temperature difference in superfluid helium is analyzed. The osmotic pressure explanation due to Tisza (1938), based on the different fractions of ground state bosons, is formulated as an ideal solution and shown to overestimate the fountain pressure by an order of magnitude or more. The experimentally confirmed thermodynamic expression of H. London (1939), in which the temperature derivative of the pressure equals the entropy per unit volume, is shown to be equivalent to equality of chemical potential, not chemical potential divided by temperature. The former results from minimizing the energy at constant entropy, whereas the latter results from maximizing the entropy. It is concluded that superfluid flow in the fountain effect is driven by mechanical, not statistical, forces. This new principle appears to be a general law for flow in superfluids and superconductors.
