先进材料疑固实验室 Macroµstate link Laboratory of Advanced Materials Solidification Macrostate: Be characterized by a few state variables,such as T,V,and U etc. Be the state of all particles in the system. Passes very rapidly through many microstates during the observation time. For example: An atom in a solid vibrates at a frequency in the order of 1013 s-1 Gas molecules have velocities of order of 102 ms-1 When we observe a property of a system,we really see the average of this property in all of the microstates that the material passed through during the observation time. 上海充通大￥ SHANGHAI JIAO TONG UNIVERSITY
Macroµstate link Macrostate: Be characterized by a few state variables, such as T, V, and U etc. Be the state of all particles in the system. Passes very rapidly through many microstates during the observation time. For example: An atom in a solid vibrates at a frequency in the order of 1013 s-1 Gas molecules have velocities of order of 102 ms-1 When we observe a property of a system, we really see the average of this property in all of the microstates that the material passed through during the observation time
先进材料疑固实验室 Main tasks Laboratory of Advanced Materials Solidification What we can do is To take advantage of the large number of the atoms in the system to make statistical descriptions of the behavior of the atoms that make up the material based on the microscopic behavior. What we really want is Statistical information regarding the motions of all particles in the system. vanced Mater 上浒充通大学 SHANGHAI JIAO TONG UNIVERSITY
Main tasks What we can do is To take advantage of the large number of the atoms in the system to make statistical descriptions of the behavior of the atoms that make up the material based on the microscopic behavior. What we really want is Statistical information regarding the motions of all particles in the system
Main Results from Quantum 先进材料疑固实验室 Mechanics Laboratory of Advanced Materials Solidification Energy is quantized-energy of a system can only take on certain discrete values.Spectroscopy-Characteristic frequency of matters） Degeneracy of level g )--the number of states with the equal energy Shifting of particles from one state to another on the same level constitutes a new arrangement. 上浒充通大学 SHANGHAI JIAO TONG UNIVERSITY
Main Results from Quantum Mechanics Energy is quantized—energy of a system can only take on certain discrete values. （Spectroscopy-Characteristic frequency of matters） Degeneracy of level（g）--the number of states with the equal energy Shifting of particles from one state to another on the same level constitutes a new arrangement
Results from Quantum 先进材料疑固实验室 Mechanics Laboratory of Advanced Materials Solidification A finite array of microstates satisfies two constraints ∑4=N=E=u Where: N:the number of particels; i:energy level; E:total energy of N particles; &,the energy of ith level nced Materials Soll 上浒充通大学 SHANGHAI JIAO TONG UNIVERSITY
A finite array of microstates satisfies two constraints Where: N: the number of particels; i:energy level; E: total energy of N particles; εi : the energy of ith level Results from Quantum Mechanics