Considering the difficulty of underground transmission of radio wave and comparing by the leakage coaxial cable,the radio leakage of single conductor at medium frequency band is analysed with theories and experiments,and the application prospect of the single conductor is expected.

Due to the difficulty of subsurface radio transmission,radio leakage of parallel leads is theoretically and experimentally analyzed compared with leaky coaxial cables,and the application is described.

The structure defect of automatically controlled vertical self-suction pump was analysised,which is commonly used in market,and the self-suction theory,structure and design of vertiacl self-suction pump with upright suction and no leakage was introduced.