4. 广义笛卡尔积 (Extended Cartesian Product Extended Cartesian Product) z R – n目关系,k1个元组 z S – m目关系,k2个元组 z R×S – 列:(n+m)列的元组的集合 z 元组的前n列是关系R的一个元组 z 后m列是关系S的一个元组 – 行:k1×k2个元组
FOUR COLONY MODELS (2) Model of New England (Puritan 1620 in Massachusetts Bay) ↓ Followed the doctrine of John Calvin (everyone had a calling given by God; read the Bible to find God's will and search for one's individual contact with God
5-1 Conservation of mass 5-2 flow work and the energy of a flowing fluid 5-3 energy analysis of steady flow systems 5-4 some steady-flow engineering devices