affect theory
4.Because concrete crack will greatly affect the security of concrete penstock in hydropower station, the paper applies the theory of global optimization method to predict the maximum concrete crack width in steel-lined reinforced concrete penstock and bring forward a predicting model based on the theory of artificial neural network (ANN).
5.The frequency properties of high efficiency Blumlein microstrip photoconductive switch (ps) and the parameters that affect the frequency band width of the output electrical pulse are discussed in theory. The results demonstrate that the PS has 100% voltage transmitting efficiency, and can generate electrical pulses with >20GHz frequency band width. The voltage transmitting efficiency of 93% and > 20GHz broad band electrical pulses are obtained in experiment.

