【简答题】Compute the torsional shear stress and the angle of twist in degrees in an aluminum tube, 600mm long, having an inside diameter of 60 mm and an ouside diameter of 80 mm when subjected to a steady torq...
【单选题】选词填空:An electron tube is generally used for amplification, and vacuum tube is another name for ______.
【单选题】在EXCEL中,要在一个单元格中输入数据,这个单元格必须是( ).
【单选题】Which of the following statements concerning the water tube and fire tube boilers is not true?()
A.
natural circulation of the water in the water tube boiler is better than that in the fire tube boiler
B.
for the same output the water tube boiler will carry less mass of water compared with the fire tube boiler
C.
the water tube boiler will cost shorter time for steam raising
D.
the water tube boiler require lower skill in operating and maintaining
【单选题】一定量理想气体由同一始态出发,分别经恒温可逆膨胀和绝热可逆膨胀到相同的终态体积 V 时,终态压力谁大( )
【判断题】由于有了会计分期这一假设,才产生了本期与非本期的区别,进而产生了权责发生制与收付实现制的区别。( )
【单选题】一定量理想气体由同一始态出发,分别经恒温可逆膨胀和绝热可逆膨胀到相同的终态压力为 p 时,终态体积谁大
【单选题】由于有了( )假设前提,才产生了本期与非本期的区别;由于有了本期与非本期的区别,才产生了权责发生制和收付实现制;才使不同类型的会计主体有了记账的基准,进而需要在会计处理上运用预收、应收、应付等会计方法。
【判断题】由于有了持续经营,才产生了本期与非本期的区别;由于有了本期与非本期的区别,才产生了权责发生制和收付实现制,才使不同类型的会计主体有了记帐的基准。
【单选题】For a double-pipe exchanger, the dimension of inner tube is Φ 19 × 2.5mm, and the dimension of outer tube is Φ 38 × 3mm, the equivalent diameter of the annular space d e is ( ).