热波传递过程中的熵产分析

傅里叶导热定律导出的温度演化方程将得出无限大的热扰动传播速率。为了克服这个问题,一些修正导热模型被提出,可以得到双曲型温度方程,保证有限的热波传播速率。但是,新的传热模型得出的温度演化将使现有的不可逆热力学中熵产不能保持正定。拓展不可逆热力学通过修正熵以及熵产的表达式,使双曲导热也能得到正定的熵产率。热质理论用力学的概...     

现代热力学的完整分类系统--非平衡非耗散热力学新领域

在同一体系中同时有多个不可逆过程时，不可逆过程之间会有相互影响，原来的非自发过程有可能在其他自发过程的影响下得以进行，这种现象就称为热力学耦合或反应耦合，长期以来，经典热力学把热力学第二定律的等式作为平衡体系的充分必要条件，其中隐含了一个前提性的假定，即经典热力学的对象只限于非耦合的体系，摈弃这一隐含的前提性假定以后，热力学自身就发展成为一个现代热力学的完整学术体系，适用于任何宏观体系（包括极其复杂的生命体系），现代热力学的完整学术体系中包含了一个崭新的非平衡非耗散热力学新领域，由于该领域属于热力学第二定律的等式部分，因此可以定量计算，并得到一系列理论计算的非平衡相图，与文献上报道的激尖低压金刚石合成等的大量实验数据相符。     

多孔介质对流干燥外部传热传质的非平衡热力学理论

从非平衡热力学理论出发,以广义热力学力作为传质过程驱动势,建立了描述多孔介质恒速干燥阶段外部对流传热传质过程的热力学理论模型,并进行了数值计算,计算值与已有的实验数据吻合较好;同时,还将计算结果与传统的理论进行了比较,结果表明,非平衡热力学理论更能反映过程的物理本质。     

周期驱动系统的非平衡热输运与热力学几何

随着对微纳尺度系统的深入理解和实验技术的进步,发生在这些小系统中的热输运和能量转换近期吸引了大量研究.不同于依赖静态热力学力(如温差、电势差等)的非平衡稳态调控手段,受时间驱动的非平衡非稳态小系统具有特有的高可调性和普遍性,其研究同时具有基础价值和应用潜力.本文从几何这一基本概念出发,分析了热力学几何相(曲率)和热力学距离这两个关键物理量,以几何的视角展现和分析近期关于受驱动非平衡量子系统中输运调控和能量转换途径的热力学研究.热力学几何不仅可以看作是这一大类系统中非平凡输运和耗散的本质起源,也同样给我们提供了一种理论框架,给出对于系统输运和能量转换的限制,同时也可以给出慢驱动条件下量子热机性能的通用优化方式.这将在未来帮助理解非平衡量子多体系统所发挥的能量输运/转换功能,也会为发现高性能(高效率、高功率、高可靠性)量子热机提供新的设计思路.     

热力学过程及物质结构对熵的影响

将宏观过程分解为多个微观过程，可以从多层面的微观角度理解宏观性质。如一般热力学过程的可逆与不可逆性的分解、导致软物质中分子发生凝聚的平移熵、描述非晶过冷及液体中相变区域分子关联运动的构型熵等。反之，利用热力学过程间的耦合原理，通过对微观过程的分解与综合，引入与分子运动相关的动态熵，可以合理地解释各种材料所表现出的不同特性，为制备新材料提供理论依据。     

熵的变化与热力学过程方程之间的联系

由热力学定律建立了熵与热力学过程方程之间的统一表示式，将它应用到理想气体，导出 的过程方程。     

满足热力学第三定律的修正的黑洞的熵公式

认为黑洞的熵正比于视界面积的熵公式S=A/4不能满足热力学第三定律,提出了新的熵公式,它既能满足热力学第三定律,又能推出黑洞的温度的表达式. 关键词： 黑洞 熵 热力学第三定律     

微滤膜热质传递的不可逆热力学分析

本文利用非平衡热力学理论分析了微滤中的透膜热质耦合传递现象,建立了相应的物理数学模型,在此基础上,探讨了各种因素对透膜通量及热流束的影响,结果表明:质量流与膜两侧的压差呈正比关系,而与膜温度呈指数关系;热流不仅与膜温度有关,还与膜两侧的压差和温差有关;在膜温度一定时,热流与膜两侧的压差和温差均呈线性关系。     

熵与热力学定律的关系

探讨熵与热力学定律的关系，并从熵函数的角度讨论热力学定律的意义。     

熵与绝热去磁制冷的物理原理

本文从熵的观点出发,利用热力学,统计物理与量子力学理论分别从宏观与微观的角度对磁制冷的物理原理进行了初等分析。     

The kinetic foundation of extended irreversible thermodynamics revisited

Extended irreversible thermodynamics (EIT) has been used mainly to study the short-time behavior of fluids and some other systems. It has also been shown how the structure of the equations of motion constructed for the so-called relaxation variables coincides with those obtained by means of Grad's method in kinetic theory. In this work we calculate the generalized entropy from the one-particle distribution function up to 26 moments. We find that the characteristics of such entropy and the equations of motion for the relaxing variables are supported by the kinetic theory. This is not the case for the hierarchical relaxation hypothesis which is used in the applications of EIT to the generalized hydrodynamic regime.On temporary leave at the Universidad Iberoamericana, Mexico.     

On the entropy production for the Davies model of heat conduction

The formula for the entropy production in open quantum systems is examined for the Davies model of heat conduction.This work is supported by Polish Ministry of Higher Education Science and Technology, project MRI 7.     

Comment on Keizer's critique on extended irreversible thermodynamics

Keizer's critique on extended irreversible thermodynamics is responded and qualified so as to remove misleading points of his statements. It is particularly pointed out that contrary to his assertion, fluctuating irreversible thermodynamics may be regarded as being included in extended irreversible thermodynamics as a special case, since it is derivable from the latter when the relaxation times of fluxes are comparatively shorter than the hydrodynamic relaxation time and the initial conditions for the evolution equations are random.Work supported by the grants from the Natural Sciences and Engineering Research Council of Canada.     

Mesoscopic transport equations and contemporary thermodynamics: an introduction

The local equilibrium hypothesis is a very successful basis for non-equilibrium thermodynamics over a wide range of phenomena and physical situations. However, the increasing interest in small systems in nanotechnology, in rarefied gases in high-altitude aeronautics, in high-frequency behaviour in information processing, or the search for new materials with sophisticated internal microstructures and tailored thermal properties have led one to ask about the limits of validity of this hypothesis, and to go beyond it. Here we do so in a constructive way, i.e. not only pointing out at these limits, but also embedding the local-equilibrium theory in a more general framework which explicitly exhibits these limits and suggests how to go beyond them, in search for a wider range of applications and a deeper understanding of the foundations.     

Nonequilibrium thermodynamics and the transport phenomena in magnetically confined plasmas

The neoclassical theory of transport in magnetically confined plasmas is reviewed. The emphasis is laid on a set of relationships existing among the banana transport coefficients. The surface-averaged entropy production in such plasmas is evaluated. It is shown that neoclassical effects emerge from the entropy production due to parallel transport processes. The Pfirsch-Schlüter effect can be clearly interpreted as due to spatial fluctuations of parallel fluxes on a magnetic surface: the corresponding entropy production is the measure of these fluctuations. The banana fluxes can be formulated in a quasithermodynamic form in which the average entropy production is a bilinear form in the parallel fluxes and the conjugate generalized stresses. A formulation as a quadratic form in the thermodynamic forces is also possible, but leads to anomalies, which are discussed in some detail.     

The effect of screening on entropy production in pattern formation

Information theory is used to study the effects of screening on the rate of entropy production during pattern formation. Screening is an effect where the outermost parts of a growing fractal pattern influence the growth probability at interior sites. The results demonstrate that a state of maximum entropy production does exist for dynamical systems which generate patterns based on simple screening rules alone. This state corresponds to a critical point where the pattern exhibits self-similarity and fractal properties typical of random aggregates. Scaling occurs because the screening transmits information from the smallest to the largest scales of the system.     

强迫耗散系统的有序结构和系统的发展(Ⅰ)，最小熵产生原理和有序结构

一个系统的发展总是由不可逆热力过程和非线性动力过程所驱动.将大气动力学方程组同考虑了动能变化的Gibbs关系结合起来构建的熵平衡方程，才能更好地描述大气系统的不可逆热力过程和非线性动力过程.至今非平衡态热力学仅利用Onsager线性唯象关系证明了最小熵产生原理.利用新建立的熵平衡方程和大气动力学方程的性质证明，最小熵产生原理在热力学线性区和非线性区都是普遍成立的.且当热量输送平衡、水汽输送平衡和动量输送平衡时，系统达到不可逆过程最弱的最小熵产生热力学状态.当系统又是动力平衡且无平流时，这种最小熵产生态就是 关键词： 非线性热力学 熵产生 最小熵产生原理 有序结构