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1.
系统理论和涨落的准热力学理论   总被引:2,自引:0,他引:2  
沈抗存 《大学物理》1997,16(12):5-7,11
讨论了系综理论和涨落的准热力学理论两者之间的联系和差别,进一步明确了它们不等效的。  相似文献   

2.
推导出了电介质系统准热力学方法的涨落概率分布,证明了类比的方法并不是任何地方都可以用的.  相似文献   

3.
沈抗存 《大学物理》1997,16(6):46-46
指出并改正了某热统教材在有关能量涨落公式推导中的一个错误。  相似文献   

4.
汪福寿 《大学物理》1990,9(10):44-45
本文讨论了涨落的准热力学理论中一个在教学中令人困扰的问题,简要地阐述了为什么在这里热力学的基本方程式对系统不适用,而对外界(热源)又适用的道理,并说明了涨落的准热力学理论是一种近似的理论.  相似文献   

5.
李述华 《大学物理》1994,13(4):9-13,17
深入地再探讨准热力学理论的一些基本问题,得出结论:适当定义的涨落态熵同平衡态熵精确地遵从一样的热力学关系;准热力学理论的涨落概率公式只能取系统理论公式的高斯近似;应十分注意准热力学理论既是系统理论的近似,又是它的推广的关系。  相似文献   

6.
讨论了系综理论和涨落的准热力学理论两者之间的联系和差别,进一步明确了它们是不等效的.  相似文献   

7.
平衡体系热力学推导涨落的前提是涨落必须很小,如果得到一个发散的结果说明这一涨落是不可靠的.对一些体系温度涨落的热力学结果,在温度趋于绝对零度时是发散的,这时必须用统计物理来处理.对这些体系进行统计物理处理的结果表明,涨落在温度趋于绝对零度时是趋于零的. 关键词: 热力学与统计物理 涨落  相似文献   

8.
在研究气体小体积元的涨落时,传统的关于大系统的平衡涨落结果是不够的.本文首先利用平均自由程方法说明了相邻的小单元之间由关联导致的对气体涨落修正的物理机制,然后运用气体输运方法计算了精确的修正结果.  相似文献   

9.
曹则贤 《物理》2021,50(11):761-766
黑体辐射是近代物理史上一只会下金蛋的鹅,是近代物理的摇篮。黑体辐射研究的意义还在于这是唯一一个涉及c,k,h三个普适常数的物理情景。黑体辐射谱抗测量误差的特性带来了辐射标准和绝对温度参照,谱分布公式对模型的不敏感则使得黑体辐射成为独特的物理研究母题。黑体辐射谱分布公式,普朗克多角度推导过,德拜推导过,艾伦菲斯特推导过,劳厄推导过,洛伦兹和庞加莱深入讨论过,泡利推导过,玻色推导过,爱因斯坦在20多年的时间里多角度推导过且产出最为丰硕,近代还有从相对论角度的推导,每一个角度的推导都带来了物理学的新内容,这包括量子力学、固体量子论、受激辐射、量子统计、相对论统计,等等。认真回顾黑体辐射研究的历史细节,考察其中的思想概念演化,不啻于体验一次教科书式的学(做)物理之旅,比如也可以尝试给出能量局域分立化的简单新证明。  相似文献   

10.
薛纭 《大学物理》2002,21(4):3-5
指出所选广义坐标使平衡点成为虚位移,进而成为广义力的奇点是导致“广义力”在平衡点上不为零的原因,而不是虚功原理本身的问题。  相似文献   

11.
In this work, we investigate the heat exchange between two quantum systems whose initial equilibrium states are described by the generalized Gibbs ensemble. First, we generalize the fluctuation relations for heat exchange discovered by Jarzynski and Wójcik to quantum systems prepared in the equilibrium states described by the generalized Gibbs ensemble at various generalized temperatures. Secondly, we extend the connections between heat exchange and the Rényi divergences to quantum systems under generic initial conditions. These relations are applicable for quantum systems with conserved quantities and universally valid for quantum systems in the integrable and chaotic regimes.  相似文献   

12.
13.
广义不确定性原理下费米气体低温热力学性质   总被引:1,自引:0,他引:1       下载免费PDF全文
李鹤龄  王娟娟  杨斌  王亚妮  沈宏君 《物理学报》2015,64(8):80502-080502
在考虑到广义不确定性原理时, 统计物理中的态密度必须做出修正, 这导致对传统统计物理的所有结果都有不同程度的修正. 在高能、高温条件下, 此修正是颠覆传统观念的, 在低温条件下, 也有一定的修正. 研究了低温条件下考虑到广义不确定性原理时, 理想费米气体和具有弱相互作用费米气体的热力学性质, 分别给出理想费米气体和弱相互作用费米气体的化学势、内能和定容热容的解析表达式, 并以铜电子气体为例进行了具体数值计算, 将计算结果与不考虑广义不确定性原理时的费米气体的热力学性质进行了比较, 探讨了广义不确定性原理对系统热力学性质的影响. 考虑到广义不确定性原理后费米气体的化学势、费米能和基态能增大, 热容减少, 内能随温度的增加先增大, 到某一温度(对于铜电子气体, T/TF0~0.3)时, 增值为零, 温度再增加内能减少. 这些修正的具体数值主要由粒子数密度决定, 粒子数密度越大, 修正越大.  相似文献   

14.
The results of recent work of Kipnis, Olla, and Varadhan on the dynamic large deviations from a hydrodynamic limit for some interacting particle models are formally extended to a general hydrodynamic situation, including non-equilibrium steady states, as a fluctuation-dissipation hypothesis. The basic conjecture is that the exponent of decay in the probability of a large thermodynamic fluctuation is given by the dissipation of the force required to produce the fluctuation. It is shown that this hypothesis leads to a nonlinear version of Onsager-Machlup fluctuation theory that had previously been proposed by Graham. A direct consequence of the theory is a dynamic variational principle for the most probable thermodynamic history subject to imposed constraints (Onsager's principle of least dissipation). Following Graham, the theory leads also to a generalized potential, analogous to an equilibrium free energy, for the nonequilibrium steady state and an associated static variational principle. Finally, a formulation of nonlinear fluctuating hydrodynamics is proposed in which the noise enters multiplicatively so as to reproduce the conjectured large-deviations theory on a formal analogy with the results of Freidlin and Wentzell for finite-dimensional systems.  相似文献   

15.
刘晓莹  张甲 《物理学报》2006,55(11):5638-5642
利用广义不确定关系修正的态密度计算了一般球对称静态黑洞附近无质量共形不变标量场、中微子场、电磁场、无质量Rarita-Schwinger场和引力场的热力学量.结果表明,黑洞附近的热力学量不仅依赖于黑洞的特征,还依赖于粒子的自旋和最小距离的尺度. 关键词: 广义不确定关系 一般球对称静态黑洞 热力学量  相似文献   

16.
We investigate the superposition of multifractals in the generalized thermodynamic formalism. It is shown analytically that phase transitions of first and second order are obtained and that the topology of the corresponding critical lines endows bicritical behavior. We demonstrate that these phase transitions can be observed in the spectrum of fractal dimensions and in the spectra of related quantities. Therefore, the obtained results are of importance for the interpretation of experimental systems.  相似文献   

17.
《中国物理 B》2021,30(7):70302-070302
The Dirac–Weyl equation characterized quasi-particles in the T3 lattice are studied under external magnetic field using the generalized uncertainty principle(GUP). The energy spectrum of the quasi-particles is found by the Nikiforov–Uvarov method. Based on the energy spectrum obtained, the thermodynamic properties are given, and the influence of the GUP on the statistical properties of systems is discussed. The results show that the energy and thermodynamic functions of massless Dirac–Weyl fermions in the T3 lattice depend on the variation of the GUP parameter.  相似文献   

18.
尚玫  梅凤翔 《中国物理 B》2009,18(8):3155-3157
This paper presents a Poisson theory of the generalized Birkhoff equations, including the algebraic structure of the equations, the sufficient and necessary condition on the integral and the conditions under which a new integral can be deduced by a known integral as well as the form of the new integral.  相似文献   

19.
By constrained spin-density functional calculations we estimate the relative role of the longitudinal and transversal fluctuations of the magnetic moments in the series of 3d metals (bcc Fe, hcp and fcc Co, and fcc Ni) for weak excitations from the ferromagnetic ground state. It is shown that the importance of longitudinal fluctuations strongly varies from relatively small in bcc Fe to large in fcc Ni. This means that a consistent adiabatic treatment of the low-energy spin fluctuations should include independent longitudinal fluctuations.  相似文献   

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