The generation mechanisms of these physical phenomena of Coulomb blockade, Coulomb staircase, single electron tunneling were described with single electron transistor(SET) as the research object.

Discontinuities of the slope of the curve at the flat form of Coulomb staircase compared to double barrier tunnel junction system, which is caused by the change of the electron num.

It can also be used to analyze the influence of tunnel resistances on the Coulomb staircase and the conductance oscillations quantitatively and to obtain the condition for the generation of single electron phenomena.

Viscous plus Coulomb friction model is employed to construct the differential equation of SDOF rotary mechanical system.

Though there are many macroscopical models in tribology,in most mechanical systems people still use traditional Coulomb Model.

The influences of the electric factors on the accuracy of the constant current coulometrictitration were introduced, such as the output undulation of the constant current source, the uncertainty of the current calibration reference, the external circuit and environmental factors.