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In [[thermodynamics]], '''dissipation''' is the result of an [[irreversible process]] that takes place in homogeneous [[Thermodynamic system|thermodynamic systems]]. A dissipative process is a process in which [[energy]] ([[Internal energy|internal]], bulk flow [[Kinetic energy|kinetic]], or system [[Potential energy|potential]]) is [[Energy transformation|transformed]] from some initial form to some final form; the capacity of the final form to do [[mechanical work]] is less than that of the initial form. For example, [[Heat Transfer|heat transfer]] is dissipative because it is a transfer of internal energy from a hotter body to a colder one. Following the [[second law of thermodynamics]], the [[entropy]] varies with [[temperature]] (reduces the capacity of the combination of the two bodies to do mechanical work), but never decreases in an isolated system.
 
In [[thermodynamics]], '''dissipation''' is the result of an [[irreversible process]] that takes place in homogeneous [[Thermodynamic system|thermodynamic systems]]. A dissipative process is a process in which [[energy]] ([[Internal energy|internal]], bulk flow [[Kinetic energy|kinetic]], or system [[Potential energy|potential]]) is [[Energy transformation|transformed]] from some initial form to some final form; the capacity of the final form to do [[mechanical work]] is less than that of the initial form. For example, [[Heat Transfer|heat transfer]] is dissipative because it is a transfer of internal energy from a hotter body to a colder one. Following the [[second law of thermodynamics]], the [[entropy]] varies with [[temperature]] (reduces the capacity of the combination of the two bodies to do mechanical work), but never decreases in an isolated system.
 
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在[[热力学]]中,“耗散”是在均质[[热力学系统|热力学系统]]中发生的[[不可逆过程]]的结果。耗散过程是一个过程,其中[[能量]]([[内能|内部]]、体积流[[动能|动能]]或系统[[势能|势能])从某种初始形式到某种最终形式的[[能量转换|转换]];最终形式做[[机械功]]的能力小于初始形式。例如,[[热传递]]具有耗散性,因为它是一种将内部能量从较热的物体转移到较冷的物体的过程。遵循[[热力学第二定律],[[熵]]随[[温度]]而变化(降低了两个物体结合起来做机械功的能力),但在孤立系统中不会降低。
 
In thermodynamics, dissipation is the result of an irreversible process that takes place in homogeneous thermodynamic systems. A dissipative process is a process in which energy (internal, bulk flow kinetic, or system potential) is transformed from some initial form to some final form; the capacity of the final form to do mechanical work is less than that of the initial form. For example, heat transfer is dissipative because it is a transfer of internal energy from a hotter body to a colder one. Following the second law of thermodynamics, the entropy varies with temperature (reduces the capacity of the combination of the two bodies to do mechanical work), but never decreases in an isolated system.
 
In thermodynamics, dissipation is the result of an irreversible process that takes place in homogeneous thermodynamic systems. A dissipative process is a process in which energy (internal, bulk flow kinetic, or system potential) is transformed from some initial form to some final form; the capacity of the final form to do mechanical work is less than that of the initial form. For example, heat transfer is dissipative because it is a transfer of internal energy from a hotter body to a colder one. Following the second law of thermodynamics, the entropy varies with temperature (reduces the capacity of the combination of the two bodies to do mechanical work), but never decreases in an isolated system.
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A particular occurrence of a dissipative process cannot be described by a single individual Hamiltonian formalism. A dissipative process requires a collection of admissible individual Hamiltonian descriptions, exactly which one describes the actual particular occurrence of the process of interest being unknown. This includes friction, and all similar forces that result in decoherency of energy—that is, conversion of coherent or directed energy flow into an indirected or more isotropic distribution of energy.
 
A particular occurrence of a dissipative process cannot be described by a single individual Hamiltonian formalism. A dissipative process requires a collection of admissible individual Hamiltonian descriptions, exactly which one describes the actual particular occurrence of the process of interest being unknown. This includes friction, and all similar forces that result in decoherency of energy—that is, conversion of coherent or directed energy flow into an indirected or more isotropic distribution of energy.
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耗散过程的特殊现象不能用单个的哈密顿形式来描述。耗散过程需要一系列可接受的个体哈密顿描述,准确地描述未知的兴趣过程的实际特殊发生。这包括摩擦力,以及所有导致能量退相干的类似作用力---- 也就是说相干或定向能量流转化为间接或更为各向同性的能量分布。
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耗散过程的一个特殊现象不能用一个单独的哈密顿形式来描述。耗散过程需要一组可容许的个体哈密顿描述集合,确切地说,哪一个描述了未知过程的实际特定发生。这包括摩擦力和所有导致能量消相干的类似力,即将相干或定向能量流转换为间接或更各向同性的能量分布
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In [[computational physics]], numerical dissipation (also known as "numerical diffusion") refers to certain side-effects that may occur as a result of a numerical solution to a differential equation. When the pure [[advection]] equation, which is free of dissipation, is solved by a numerical approximation method, the energy of the initial wave may be reduced in a way analogous to a diffusional process. Such a method is said to contain 'dissipation'. In some cases, "artificial dissipation" is intentionally added to improve the [[numerical stability]] characteristics of the solution.<ref>Thomas, J.W. Numerical Partial Differential Equation: Finite Difference Methods. Springer-Verlag. New York. (1995)</ref>
 
In [[computational physics]], numerical dissipation (also known as "numerical diffusion") refers to certain side-effects that may occur as a result of a numerical solution to a differential equation. When the pure [[advection]] equation, which is free of dissipation, is solved by a numerical approximation method, the energy of the initial wave may be reduced in a way analogous to a diffusional process. Such a method is said to contain 'dissipation'. In some cases, "artificial dissipation" is intentionally added to improve the [[numerical stability]] characteristics of the solution.<ref>Thomas, J.W. Numerical Partial Differential Equation: Finite Difference Methods. Springer-Verlag. New York. (1995)</ref>
 
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在[[计算物理]]中,数值耗散(也称为“数值扩散”)是指微分方程数值解可能产生的某些副作用。当用数值近似方法求解无耗散的纯[[平流]]方程时,初始波的能量可以用类似于扩散过程的方式降低。这种方法被称为包含“耗散”。在某些情况下,故意添加“人工耗散”来改善解的[[数值稳定性]]特性。
 
In computational physics, numerical dissipation (also known as "numerical diffusion") refers to certain side-effects that may occur as a result of a numerical solution to a differential equation. When the pure advection equation, which is free of dissipation, is solved by a numerical approximation method, the energy of the initial wave may be reduced in a way analogous to a diffusional process. Such a method is said to contain 'dissipation'. In some cases, "artificial dissipation" is intentionally added to improve the numerical stability characteristics of the solution.
 
In computational physics, numerical dissipation (also known as "numerical diffusion") refers to certain side-effects that may occur as a result of a numerical solution to a differential equation. When the pure advection equation, which is free of dissipation, is solved by a numerical approximation method, the energy of the initial wave may be reduced in a way analogous to a diffusional process. Such a method is said to contain 'dissipation'. In some cases, "artificial dissipation" is intentionally added to improve the numerical stability characteristics of the solution.
  
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