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第118行： − + − 第二定律 − − The [[second law of thermodynamics]] indicates the irreversibility of natural processes and, in many cases, the tendency of natural processes to lead towards spatial homogeneity of matter and energy, and especially of temperature. It can be formulated in a variety of interesting and important ways. − − The second law of thermodynamics indicates the irreversibility of natural processes and, in many cases, the tendency of natural processes to lead towards spatial homogeneity of matter and energy, and especially of temperature. It can be formulated in a variety of interesting and important ways. − + − − It implies the existence of a quantity called the [[entropy]] of a thermodynamic system. In terms of this quantity it implies that − − It implies the existence of a quantity called the entropy of a thermodynamic system. In terms of this quantity it implies that − − 这意味着热力学系统中存在一个叫做熵的量。就这个数量而言，它意味着 − − {{quote|When two initially isolated systems in separate but nearby regions of space, each in [[thermodynamic equilibrium]] with itself but not necessarily with each other, are then allowed to interact, they will eventually reach a mutual thermodynamic equilibrium. The sum of the [[entropy|entropies]] of the initially isolated systems is less than or equal to the total entropy of the final combination. Equality occurs just when the two original systems have all their respective intensive variables (temperature, pressure) equal; then the final system also has the same values.}}<br> − 当两个最初隔离的系统分别位于彼此独立但不一定彼此处于热力学平衡的空间区域中，然后彼此相互作用时，它们最终将达到相互的热力学平衡。最初隔离的系统的熵之和小于或等于最终组合的总熵。当两个初始系统各自的强变量(温度、压力)相等时，才发生平等。那么最终的系统也有相同的值。 − − − − The second law is applicable to a wide variety of processes, reversible and irreversible. All natural processes are irreversible. Reversible processes are a useful and convenient theoretical fiction, but do not occur in nature. − − The second law is applicable to a wide variety of processes, reversible and irreversible. All natural processes are irreversible. Reversible processes are a useful and convenient theoretical fiction, but do not occur in nature. − − − − A prime example of irreversibility is in the transfer of heat by conduction or radiation. It was known long before the discovery of the notion of entropy that when two bodies initially of different temperatures come into thermal connection, then heat always flows from the hotter body to the colder one. − − A prime example of irreversibility is in the transfer of heat by conduction or radiation. It was known long before the discovery of the notion of entropy that when two bodies initially of different temperatures come into thermal connection, then heat always flows from the hotter body to the colder one. − − − − The second law tells also about kinds of irreversibility other than heat transfer, for example those of friction and viscosity, and those of chemical reactions. The notion of entropy is needed to provide that wider scope of the law. − − The second law tells also about kinds of irreversibility other than heat transfer, for example those of friction and viscosity, and those of chemical reactions.'''<font color="#32CD32"> The notion of entropy is needed to provide that wider scope of the law.</font>''' − − − According to the second law of thermodynamics, in a theoretical and fictive reversible heat transfer, an element of heat transferred, ''δQ'', is the product of the temperature (''T''), both of the system and of the sources or destination of the heat, with the increment (''dS'') of the system's conjugate variable, its [[entropy]] (''S'') − − According to the second law of thermodynamics, in a theoretical and fictive reversible heat transfer, an element of heat transferred, δQ, is the product of the temperature (T), both of the system and of the sources or destination of the heat, with the increment (dS) of the system's conjugate variable, its entropy (S) − − − :<math>\delta Q = T\,dS\, .</math><ref name="Guggenheim 1985"/>+ − − − − − − [[Entropy]] may also be viewed as a physical measure of the lack of physical information about the microscopic details of the motion and configuration of a system, when only the macroscopic states are known. This lack of information is often described as ''disorder'' on a microscopic or molecular scale. The law asserts that for two given macroscopically specified states of a system, there is a quantity called the difference of information entropy between them. This information entropy difference defines how much additional microscopic physical information is needed to specify one of the macroscopically specified states, given the macroscopic specification of the other – often a conveniently chosen reference state which may be presupposed to exist rather than explicitly stated. A final condition of a natural process always contains microscopically specifiable effects which are not fully and exactly predictable from the macroscopic specification of the initial condition of the process. This is why entropy increases in natural processes – the increase tells how much extra microscopic information is needed to distinguish the final macroscopically specified state from the initial macroscopically specified state.<ref>Ben-Naim, A. (2008). ''A Farewell to Entropy: Statistical Thermodynamics Based on Information'', World Scientific, New Jersey, {{ISBN|978-981-270-706-2}}.</ref> − − Entropy may also be viewed as a physical measure of the lack of physical information about the microscopic details of the motion and configuration of a system, when only the macroscopic states are known. This lack of information is often described as disorder on a microscopic or molecular scale. The law asserts that for two given macroscopically specified states of a system, there is a quantity called the difference of information entropy between them.'''<font color="#32CD32"> This information entropy difference defines how much additional microscopic physical information is needed to specify one of the macroscopically specified states, given the macroscopic specification of the other – often a conveniently chosen reference state which may be presupposed to exist rather than explicitly stated. A final condition of a natural process always contains microscopically specifiable effects which are not fully and exactly predictable from the macroscopic specification of the initial condition of the process. This is why entropy increases in natural processes – the increase tells how much extra microscopic information is needed to distinguish the final macroscopically specified state from the initial macroscopically specified state.</font>''' − 当只知道宏观状态时，熵也可以被看作是对系统运动和构型的微观细节有关的物理度量。这种细节通常在微观或分子尺度上被称为无序。该定律声称，对于一个系统的两个给定的宏观指定状态，它们之间存在一个被称为熵差的量。'''<font color="#32CD32">这种熵的差异定义了需要多少额外的微观物理信息来指定一个宏观指定状态，给定另一个宏观指定状态-通常是一个方便选择的参考状态，这可能是假定存在的，而不是明确陈述的。自然过程的最终条件始终包含着微观上特定的影响，而这些影响，从过程初始条件的宏观规定来看是无法被完全准确预测的。这就是为什么熵在自然过程中会增加——熵的增加告诉我们需要多少额外的微观信息来区分最终的宏观指定状态和最初的宏观指定状态。</font>'''+
→Second law
结合这些原理，就可以得出传统的热力学第一定律的表述: 不可能制造一台在没有等量能量输入的情况下不断做功的机器。或者更简单地说，第一类永动机是不可能造成的。
结合这些原理，就可以得出传统的热力学第一定律的表述: 不可能制造一台在没有等量能量输入的情况下不断做功的机器。或者更简单地说，第一类永动机是不可能造成的。
==Second law==
==第二定律 Second law==
热力学第二定律表明了自然过程的不可逆性，并且在许多情况下，自然过程的趋向于物质和能量的空间均匀性，特别是温度。它可以用各种有趣而重要的方式来表达。
热力学第二定律表明了自然过程的不可逆性，并且在许多情况下，自然过程的趋向于物质和能量的空间均匀性，特别是温度。它可以用各种有趣而重要的方式来表达。
这意味着热力学系统中存在一个叫做熵的量。就这个数量而言，它意味着当两个最初隔离的系统分别位于彼此独立但不一定彼此处于热力学平衡的空间区域中，然后彼此相互作用时，它们最终将达到相互的热力学平衡。最初隔离的系统的熵之和小于或等于最终组合的总熵。当两个初始系统各自的强变量(温度、压力)相等时，才发生平等。那么最终的系统也有相同的值。
第二定律适用于可逆和不可逆的多种过程。所有的自然过程都是不可逆的。可逆过程是一个有用的和方便的理论假设，但不发生在自然界。
第二定律适用于可逆和不可逆的多种过程。所有的自然过程都是不可逆的。可逆过程是一个有用的和方便的理论假设，但不发生在自然界。
这种不可逆性的一个主要例子是通过传导或辐射进行的热传递。早在熵的概念被发现之前，人们就已经知道，当两个最初温度不同的物体直接进行热连接时，热量总是从较热的物体流向较冷的物体。
这种不可逆性的一个主要例子是通过传导或辐射进行的热传递。早在熵的概念被发现之前，人们就已经知道，当两个最初温度不同的物体直接进行热连接时，热量总是从较热的物体流向较冷的物体。
第二定律也告诉我们除了热传递之外的不可逆性，例如摩擦力和粘度，以及化学反应。'''<font color="#32CD32">该定律应给熵的概念提供更广泛的范围。</font>'''
第二定律也告诉我们除了热传递之外的不可逆性，例如摩擦力和粘度，以及化学反应。'''<font color="#32CD32">该定律应给熵的概念提供更广泛的范围。</font>'''
根据热力学第二定律，在理论上和假设的可逆传热中，传热元素''δQ''是系统和热源或热目的地的温度(t)与系统共轭变量熵（S）的增量(dS)的乘积
根据热力学第二定律，在理论上和假设的可逆传热中，传热元素''δQ''是系统和热源或热目的地的温度(t)与系统共轭变量熵（S）的增量(dS)的乘积
:<math>\delta Q = T\,dS\, .</math><ref name="Guggenheim 1985"/>
:<math>\delta Q = T\,dS\, .</math><ref name="Guggenheim 1985"/>
当只知道宏观状态时，熵也可以被看作是对系统运动和构型的微观细节有关的物理度量。这种细节通常在微观或分子尺度上被称为无序。该定律声称，对于一个系统的两个给定的宏观指定状态，它们之间存在一个被称为熵差的量。'''<font color="#32CD32">这种熵的差异定义了需要多少额外的微观物理信息来指定一个宏观指定状态，给定另一个宏观指定状态-通常是一个方便选择的参考状态，这可能是假定存在的，而不是明确陈述的。自然过程的最终条件始终包含着微观上特定的影响，而这些影响，从过程初始条件的宏观规定来看是无法被完全准确预测的。这就是为什么熵在自然过程中会增加——熵的增加告诉我们需要多少额外的微观信息来区分最终的宏观指定状态和最初的宏观指定状态。</font>'''<ref>Ben-Naim, A. (2008). ''A Farewell to Entropy: Statistical Thermodynamics Based on Information'', World Scientific, New Jersey, {{ISBN|978-981-270-706-2}}.</ref>
'''<font color="#32CD32"> This information entropy difference defines how much additional microscopic physical information is needed to specify one of the macroscopically specified states, given the macroscopic specification of the other – often a conveniently chosen reference state which may be presupposed to exist rather than explicitly stated. A final condition of a natural process always contains microscopically specifiable effects which are not fully and exactly predictable from the macroscopic specification of the initial condition of the process. This is why entropy increases in natural processes – the increase tells how much extra microscopic information is needed to distinguish the final macroscopically specified state from the initial macroscopically specified state.</font>'''
==Third law==
==Third law==