الفهرس 
CHAPTER IOnly 14 pages are availabe for public view
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Abstract
Thermal lagging behavior is simply the non-instantaneous response between the heat flux and the temperature gradient of the Fourier law of heat conduction when it is employed in a mathematical description of any non-equilibrium heat transfer situations. Non-equilibrium transition of thermodynamic states often occurs during the ultrafast transient; in times comparable to the intrinsic times of the transition form a state to another. Thermalization time between electrons and phonons in metals, electron-electron, electron-phonon, and phonon-phonon relaxation times are all examples for such intrinsic times. This chapter will focus on the thermal lagging behavior that should be imposed on the classical Fourier law to be adequate to mathematically describe the general behavior of the ultrafast situations. Firstly, thermodynamically established models in microscale heat transfer will be illustrated. The concept of the lagging behavior will be illustrated. Direct correlations between the defined microscale heat transfer models and the delayed equation of the classical Fourier model will be established. The physical meanings of the time constants of the delayed forms of the Fourier diffusion are derived, finally.