假定我们对一个处于热平衡的恒温(T的体系感兴趣。对该 热力学问题我们做如下的表述。设有一个包含N个粒子的恒温的 平衡态系统,我们要计算该系统的可观测量A,即该物理量的平 均值 (A(T)=2-A( ((') 其中H(x)为系统的哈密顿量描述,f(为分布密度函数,称为 配分函数,它是归一化常数

1.正弦波振荡电路能够振荡的条件起振条件:AF>1A+F=2nT正弦波振荡器的稳幅振荡条件:幅值平衡条件

Unit 6 Day-to-day work 6.1 Talking about your work (1)Listening Listen to Ana Campos talking about her working hours. Are these statements true (T)or false(F)? 1 She starts works at 7.30. 2 She finishes work at 4.00 3 She has lunch at 12.00. 4 She has one hour for lunch. 5 She works a 40-hour week

一、以2L为周期的傅氏级数定理设周期为21的周期函数f(x)满足收敛定理的条件则它的傅里叶级数展开式为