Thermal Physics

Course Code: B21002Y-A03

Course Name: Thermal Physics

Credits: 4.0

Level: Undergraduate  

Pre-requisite: Advanced Mathematics

Lecture Time: 36 sessions, 2 hours/session

Course Description

Students are needed to systematically do research on and deal with thermal physical properties of systems consisting of large number of particles, master statistical rules and fundamental character, learn how to apply statistical methods to process multi particle systems, and master basic laws of thermodynamics and basic concepts. Students are also required to get to know transport process, concept of phase and properties and characteristics of multi-phase equilibrium, and understand bulk and surface properties of liquids.

Topics and Schedule

1. Equilibrium State and State Equation
    1.1. State parameter and equilibrium state: thermodynamic system, state parameter, equilibrium state;

    1.2. Temperature: concept of temperature, the zeroth law of thermodynamics, thermometric scale;
1.3. State equation: classical system, state equation of ideal gas, Van der Waals' Equation;
1.4. Microscopic image of ideal gas: microscopic structure of matter, microscopic model of ideal gas, pressure formula of ideal gas; statistical significance and microscopic interpretation of temperature, heat transfer process of ideal gas.

2.  Statistical Law of Equilibrium System

2.1. Disordered system: statistical law of random movement, a simple analysis of the Brown movement;

2.2. Introduction to probability theory (can be neglected if the lecture of probability theory has been given);
2.3. Maxwell distribution of velocity and rate distribution: Maxwell distribution of velocity, Maxwell distribution of rate, application of velocity distribution and rate distribution;
2.4. Most probable distribution of nearly independent particle system: basic concept, equal probability principle, most probable distribution (Maxwell-Boltzmann distribution), from M-B distribution to Maxwell distribution of velocity;

    2.5. General form of Boltzmann distribution: the isothermal distribution of particles in the gravitational field, Boltzmann density distribution rate, Maxwell Boltzmann distribution rate;

    2.6. Energy equipartition principle and heat capacity: freedom degrees of molecule, energy equipartition principle, internal energy and heat capacity of quasi ideal gas;

    2.7. Introduction to quantum gas.

3.  Transport Processes in Near Equilibrium State
    3.1. Collision frequency and mean free path of gas: effective collision cross-section and collision rate, mean collision rate and mean free path, mean free path distribution of gas molecule;

3.2. Macroscopic law of transport phenomena: basic concept, macroscopic law of viscosity phenomenon; macroscopic law of heat transfer;
3.3. Microscopic interpretation of transport phenomena in gases: basic assumptions, flow in the transport process, derivation of transport sparsity, transport phenomena of low density gas.

4.  The First Law of Thermodynamics

4.1.The first law of thermodynamics: energy conservation law, work- energy transfer under the action of mechanics, heat quantity-- energy transfer under the action of thermodynamics, internal energy of a thermodynamic system--internal energy, the first law of thermodynamics;
4.2. Application of the first law of thermodynamics: quasi-static process, heat capacity, internal energy and enthalpy, application of the first law of thermodynamics to ideal gas: heat capacity of ideal gas, thermal process;
4.3. Cycle process and Kano cycle: cycle process, Kano cycle and efficiency of ideal gas;

   4.4. Entropy function and the microscopic image of the first law: state function representation of the first law, the introduction of entropy function, microscopic interpretation of the first law.

5. The Second Law of Thermodynamics

    5.1. Expression of the second law of thermodynamics and Kano theorem: expression of the second law of thermodynamics; mathematical expression of the second law of thermodynamics, examples of the application of Kano theorem;

    5.2. Entropy and entropy theorem: concept of entropy, computation of entropy, principle of entropy increase;

5.3. Entropy and statistical interpretation of the second law of thermodynamics: Boltzmann entropy, the statistical significance of the second law of thermodynamics, the law of entropy is statistical rule;

5.4. Free energy, free enthalpy and thermodynamic equation: Helmholtz free energy, maximum work principle, Gibbs function, free enthalpy, state functions of thermodynamic system and their relations;
   5.5. The third law of thermodynamics: the relationship between thermodynamic temperature scale and actual temperature scale; standard reference point of entropy, the third law of thermodynamics.
6.  Fluid

6.1. Bulk property of liquid: approaching from the theory of gas, approaching from the theory of solid;

    6.2. Surface property of liquid: surface tension and surface energy, the relationship between surface tension coefficient and temperature, Laplace formula;

    6.3. Surface contact angle, capillary phenomenon.

7.  Multi-phase equilibrium and phase transition of unit system
7.1. Concept of phase, phase transition, phase equilibrium: stability condition of equilibrium state, phase equilibrium, phase rule, concept of phase transition;
Multi-phase equilibrium of unit system: equilibrium condition, Clapyron Equation, vapor liquid phase transition, Van der Waals isotherm, metastable state;

   7.3. Liquid gas phase transition: form of liquid gas phase transformation, spinodal decomposition and nucleation and growth, metastable state, boiling and condensation.


Regular grade 10% (homework5%+discussion5%)

Midterm Examination 40% (Closed-book written examination)

Final Examination 50 (Closed-book written examination)

Exercise class arrangements

Exercise class: 12 hrs

Seminar: 6 hrs


Chun Li, Li-Yuan Zhang, Shang-Wu Qian, Thermal Physics, Higher Education Press, 2008,  Second Edition


[1] Kai-Hua Zhao, Wei-Yin Luo, New Concept Physics-Thermal physics, (Higher Education Press, 2005, Second Edition)

[2] Ke-Da Bao, Textbook Series for 21st Century-Fundamental of Thermal Physics (Higher Education Press, 2004)
[3] Yun-Hao Qin, General Physics Course-Thermal physics (Higher Education Press, 2011, Second Edition )

[4] Zong-Han Lin, Thermodynamics and Statistical Physics (Peking University press, 2007)