A method of measuring an ac force by a scanning probe system is proposed.

This paper treats of the transient characteristics of the magnetic tachometer s working system and theoretically analyses the law of how the pointer vacillates with the tachometric variation under the work of an extra alternating torque.

This article introduces the characteristic and function of AC-AC frequency conversion vector control system used in main driving motor in the CSP finishing mill,and expatiates the basic theory of AC-AC frequency conversion vector control.

Formation and control of turbulent in metal melts purified by alternating magnetic field;

Measuring alternating magnetic field and permeability of vacuum by oscillograph;

The study of heat effect of magnetic fluids under an alternating magnetic field;