Unit1 Two methods of designating limit dimensions are considered as standard.One method is the maximum material method in which the large dimension is placed above the smaller dimension for male parts, and the reverse is true for female parts.This method is well suited for small lot quantities because it is likely that the machinist himself may check the dimension of the parts .In so doing he will be verifying initially the large dimension of the male parts and the smaller dimension of the female part.other method is the maximum number method and is preferred by production and quality control departments .In this method of designating a dimension , the large number is always placed above the smaller number ,regardless of whether the part is male or female. 两种方法都被看作是指定极限尺寸标准。一种方法是最大的资料法,大尺寸较小的尺寸摆在上面男性部件,事实正相反对女性的部分。这种方法很适合小批量的数量,因为它是可能的,自己可能检查机械师维度的零件。 这样做的话,他就会验证最初的男大尺寸零件和小尺寸的女性的部分。另一个方法是最大的数字方法和优先生产和质量控制部门。在该方法中,指定了一个维度,大量总是摆在上面较小的号码,不管部分男” 或“ 女” 。 Unit3 (1) From its inception ,quantum mechanics had two apparently different mathematical forms: the wave mechanics of E.Sehrodinger ,which emphasizes the spatial probability distributions in the quantum states ,and the matrix mechanics of W.Heisenberg, which emphasizes the transitions between states. 成立以来,量子力学有两个明显不同的数学形态 E.Sehrodinger 波动力学的,它强调在空间概率分布的量子状态时,矩阵力学的 W.Heisenberg,他们 (2) the rigid-body assumption cannot be used when internal stresses and strains due to the applied forces are to be analyzed. Thus we consider the body to be capable of deforming .such analysis is frequently...
