Counterfort retaining walls are optimized in the paper, using the optimum program, costs of different counterfort retaining wall parameters were calculated and based on the contrast analysis.

本文对扶壁式挡土墙进行优化,用优化设程序对不同参数下的面状态和工程造价进行分析比较。

The theory of medical microtron is introduced.The theory of medical runway microtron is expressed and its characteristics are compared with electron linear accelerator.

绍了电子回旋加速器原理，点绍了跑道式电子回旋加速器的工作原理，并对电子回旋加速器和电子直线加速器的特点进行了比较。