dT/dp is mu JT. So for a real gas like air, this is a positive number. It's not zero.

所以对于像空气这样的真实气体，这是一个正数，不等于零。

麻省理工公开课 - 热力学与动力学课程节选

But a real key in looking at these plots is where we, in fact, did go through zero and have this zero probability density.

是我们经历这些零值,而且有这些零概率密度,我们把它叫做节点。

麻省理工公开课 - 化学原理课程节选

u=0 And it's approximately equal to zero for all real gas processes.

在所有理想气体绝热过程中Δ,对真实气体近似为零。

麻省理工公开课 - 热力学与动力学课程节选

According to this calculation, rates could drop another full percentage point before the Fed hits "real" zero.

BBC: Analysis: The Fed's next move

Most urgently today, in contrast, and given what we here at BullionVault have long said about how real interest rates drive gold, sub-zero real rates look highly likely to keep driving gold until 2013 (and beyond) thanks to central bankers being obsessed with avoiding deflation.

FORBES: Gold Still Shines In A Deflationary World, Just Ask Paul Krugman

It is true that the bonds were sold at less than zero real yields.

FORBES: UK Government Bond Yields Go Below Zero