| − | A thermodynamic operation may occur as an event restricted to the walls that are within the surroundings, directly affecting neither the walls of contact of the system of interest with its surroundings, nor its interior, and occurring within a definitely limited time. For example, an immovable adiabatic wall may be placed or removed within the surroundings. Consequent upon such an operation restricted to the surroundings, the system may be for a time driven away from its own initial internal state of thermodynamic equilibrium. Then, according to the second law of thermodynamics, the whole undergoes changes and eventually reaches a new and final equilibrium with the surroundings. Following Planck, this consequent train of events is called a natural [[thermodynamic process]].<ref>[[Edward A. Guggenheim|Guggenheim, E.A.]] (1949/1967), § 1.12.</ref> It is allowed in equilibrium thermodynamics just because the initial and final states are of thermodynamic equilibrium, even though during the process there is transient departure from thermodynamic equilibrium, when neither the system nor its surroundings are in well defined states of internal equilibrium. A natural process proceeds at a finite rate for the main part of its course. It is thereby radically different from a fictive quasi-static 'process' that proceeds infinitely slowly throughout its course, and is fictively 'reversible'. Classical thermodynamics allows that even though a process may take a very long time to settle to thermodynamic equilibrium, if the main part of its course is at a finite rate, then it is considered to be natural, and to be subject to the second law of thermodynamics, and thereby irreversible. Engineered machines and artificial devices and manipulations are permitted within the surroundings.<ref>Levine, I.N. (1983), p. 40.</ref><ref>Lieb, E.H., Yngvason, J. (1999), pp. 17–18.</ref> The allowance of such operations and devices in the surroundings but not in the system is the reason why Kelvin in one of his statements of the second law of thermodynamics spoke of [[Second law of thermodynamics#Description#Kelvin statement|"inanimate" agency]]; a system in thermodynamic equilibrium is inanimate.<ref>[[William Thomson, 1st Baron Kelvin|Thomson, W.]] (1851).</ref>
| + | 热力操作可能作为一个事件发生在周围环境的壁上，既不直接影响与周围环境联系的壁，也不直接影响其内部，且发生在一个明确的有限的时间内。例如，一个固定的绝热壁可以在环境中被放置或拆除。由于这种操作仅限于周围环境，系统可能会在一段时间内远离自身最初的内部状态---- 热力学平衡。根据热力学第二定律的说法，整体经历了变化并最终与周围环境达到了新的平衡。继Planck之后，这一连串的事件被称为自然'''<font color="#ff8000">热力学过程 Thermodynamic Process</font>'''.<ref>[[Edward A. Guggenheim|Guggenheim, E.A.]] (1949/1967), § 1.12.</ref> 。即使在这个过程中，当系统和周围环境都不处于明确的内部平衡状态时，存在着暂时偏离热力学平衡的现象，由于初始状态和最终状态都是热力学平衡的，这在平衡热力学中也是允许的。一个自然过程在其主要部分中以有限的速率进行，因此，它从根本上不同于虚构的准静态“过程”；即不在整个过程中无限缓慢地进行而且虚构地“可逆”。经典热力学允许，即使一个过程可能需要很长的时间才能达到热力学平衡，如果主要部分的过程是在一个有限的比率中，那么它被认为是自然的，并受制于热力学第二定律，即不可逆的。工程设计的机器、人工设备和操作是允许在周围环境中进行的<ref>Levine, I.N. (1983), p. 40.</ref><ref>Lieb, E.H., Yngvason, J. (1999), pp. 17–18.</ref> 。允许在环境中而不是在系统中进行此类操作和设备，是开尔文在他的一个热力学第二定律的陈述中提到'''<font color="#ff8000">无生命机构 Inanimate Agency</font>'''的原因; 在热力学平衡的系统是无生命的。<ref>[[William Thomson, 1st Baron Kelvin|Thomson, W.]] (1851).</ref> |
| − | A thermodynamic operation may occur as an event restricted to the walls that are within the surroundings, directly affecting neither the walls of contact of the system of interest with its surroundings, nor its interior, and occurring within a definitely limited time. For example, an immovable adiabatic wall may be placed or removed within the surroundings. Consequent upon such an operation restricted to the surroundings, the system may be for a time driven away from its own initial internal state of thermodynamic equilibrium. Then, according to the second law of thermodynamics, the whole undergoes changes and eventually reaches a new and final equilibrium with the surroundings. Following Planck, this consequent train of events is called a natural thermodynamic process. It is allowed in equilibrium thermodynamics just because the initial and final states are of thermodynamic equilibrium, even though during the process there is transient departure from thermodynamic equilibrium, when neither the system nor its surroundings are in well defined states of internal equilibrium. A natural process proceeds at a finite rate for the main part of its course. It is thereby radically different from a fictive quasi-static 'process' that proceeds infinitely slowly throughout its course, and is fictively 'reversible'. Classical thermodynamics allows that even though a process may take a very long time to settle to thermodynamic equilibrium, if the main part of its course is at a finite rate, then it is considered to be natural, and to be subject to the second law of thermodynamics, and thereby irreversible. Engineered machines and artificial devices and manipulations are permitted within the surroundings. The allowance of such operations and devices in the surroundings but not in the system is the reason why Kelvin in one of his statements of the second law of thermodynamics spoke of "inanimate" agency; a system in thermodynamic equilibrium is inanimate.
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