对于蒸汽动力循环要提高热效率，可采取一系列措施，以下说法不正确的是（）。 A: 同一Rankine循环动力装置，可提高蒸气过热温度和蒸汽压力 B: 同一Rankine循环动力装置，可提高乏气压力。 C: 对Rankine循环进行改进，采用再热循环。 D: 对Rankine循环进行改进，采用回热循环。
对于蒸汽动力循环要提高热效率，可采取一系列措施，以下说法不正确的是（）。 A: 同一Rankine循环动力装置，可提高蒸气过热温度和蒸汽压力 B: 同一Rankine循环动力装置，可提高乏气压力。 C: 对Rankine循环进行改进，采用再热循环。 D: 对Rankine循环进行改进，采用回热循环。
Which indexes are economic indexes of Rankine Cycle ( ) A: Thermal efficiency B: Coal rate C: Heat rate D: Steam rate
Which indexes are economic indexes of Rankine Cycle ( ) A: Thermal efficiency B: Coal rate C: Heat rate D: Steam rate
For the following cycles, which belong to power cycles ( ) A: Reheat Cycle B: Regenerate Cycle C: Rankine Cycle D: Refrigeration Cycle
For the following cycles, which belong to power cycles ( ) A: Reheat Cycle B: Regenerate Cycle C: Rankine Cycle D: Refrigeration Cycle
According to Maximum Principal Stress theory (also known as Rankine's theory of failure), elastic failure occurs ( ) A: when the minor principal stress is equal to the elastic limits value in a simple tension test B: when the greatest principal stress reaches the elastic limit value in simple tension test C: when the greatest principal stress is equal to the stress corresponding to the upper yield limit in a tension test D: none of the above
According to Maximum Principal Stress theory (also known as Rankine's theory of failure), elastic failure occurs ( ) A: when the minor principal stress is equal to the elastic limits value in a simple tension test B: when the greatest principal stress reaches the elastic limit value in simple tension test C: when the greatest principal stress is equal to the stress corresponding to the upper yield limit in a tension test D: none of the above
朗肯土压力理论是内英国科学家朗肯（rankine)于1857年提出。朗肯理论的基本假定为：（1)挡土墙背竖直，墙面为光滑，不计墙面和土层之间的摩擦力;（2)挡土墙后填土的表面为水平面，土体向下和沿水平方向都能伸展到无穷，即为半无限空间;（3)挡土墙后填土处于极限平衡状态。（)
朗肯土压力理论是内英国科学家朗肯（rankine)于1857年提出。朗肯理论的基本假定为：（1)挡土墙背竖直，墙面为光滑，不计墙面和土层之间的摩擦力;（2)挡土墙后填土的表面为水平面，土体向下和沿水平方向都能伸展到无穷，即为半无限空间;（3)挡土墙后填土处于极限平衡状态。（)