更改

--[[用户:嘉树|嘉树]]（[[用户讨论:嘉树|讨论]]） 这里的公式和备注貌似有误，公式应为 <math>\mathrm dS = \frac{\delta Q}{T}，备注应为“closed system, idealized fictive reversible process”封闭系统，理想的可逆过程。或者？

--[[用户:嘉树|嘉树]]（[[用户讨论:嘉树|讨论]]） 这里的公式和备注貌似有误，公式应为 <math>\mathrm dS = \frac{\delta Q}{T}，备注应为“closed system, idealized fictive reversible process”封闭系统，理想的可逆过程。或者？

Different notations are used for infinitesimal amounts of heat ({{mvar|δ}}) and infinitesimal amounts of entropy ({{mvar|d}}) because entropy is a [[function of state]], while heat, like work, is not. For an actually possible infinitesimal process without exchange of mass with the surroundings, the second law requires that the increment in system entropy fulfills the [[Clausius Theorem|inequality]] <ref name="MortimerBook"> Mortimer, R. G. ''Physical Chemistry''. 3rd ed., p. 120, Academic Press, 2008. </ref><ref name="FermiBook"> Fermi, E. ''Thermodynamics'', footnote on p. 48, Dover Publications,1956 (still in print). </ref>  

Different notations are used for infinitesimal amounts of heat ({{mvar|δ}}) and infinitesimal amounts of entropy ({{mvar|d}}) because entropy is a [[function of state]], while heat, like work, is not. For an actually possible infinitesimal process without exchange of mass with the surroundings, the second law requires that the increment in system entropy fulfills the [[Clausius Theorem|inequality]] <ref name="MortimerBook"> Mortimer, R. G. ''Physical Chemistry''. 3rd ed., p. 120, Academic Press, 2008. </ref><ref name="FermiBook"> Fermi, E. ''Thermodynamics'', footnote on p. 48, Dover Publications,1956 (still in print). </ref>