Fisher ME, Orkoulas G
Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2000 Jul 24;85(4):696-9. doi: 10.1103/PhysRevLett.85.696.
Yang and Yang proved that the divergence of C(V)(T) at a gas-liquid critical point implies that either d(2)p/dT(2) identical withp(")(sigma) or d(2)&mgr;/dT(2) identical with&mgr;(")(sigma) or both diverge when T-->T(c)- on the phase boundary sigma. They queried the lattice-gas prediction that &mgr;(")(sigma) remains finite. Analysis of two-phase heat-capacity data provides, for the first time, evidence for such a Yang-Yang anomaly (&mgr;(")(sigma)-->+/-infinity) in propane and suggests an anomaly of opposite sign in CO (2). A revision of standard scaling theory for fluid criticality is demanded: specifically, p-p(c) must appear in the ordering field. The coexistence diameter hence gains a |T-T(c)|(2beta) term.
杨和杨证明，在气液临界点处C(V)(T)的发散意味着，在相边界σ上，当T→T(c)-时，要么d(2)p/dT(2)与p(")(σ)相同，要么d(2)μ/dT(2)与μ(")(σ)相同，或者两者都发散。他们对晶格气体预测μ(")(σ)保持有限提出了质疑。对两相热容数据的分析首次提供了丙烷中这种杨 - 杨异常（μ(")(σ)→±∞）的证据，并表明CO(2)中存在相反符号的异常。需要对流体临界性的标准标度理论进行修正：具体而言，p - p(c)必须出现在有序场中。因此，共存直径获得了一个|T - T(c)|(2β)项。
