Abstract: A device and a method for nondestructively detecting a transient characteristic of a conductive screw of a turbo-generator rotor are provided. The device includes a personal computer (PC), an extremely-steep pulse generator, an ultra-high-frequency double-isolation transformer, and a pulse emitting and coupling module, which are connected in sequence. The pulse emitting and coupling module is connected to a load. A synchronous pulse receiving non-inductive divider circuit synchronously receives a characteristic waveform from the load, and the synchronous pulse receiving non-inductive divider circuit is connected to an ultra-high-speed analog/digital (A/D) module through a nonlinear saturation amplifying circuit that amplifies a signal. The PC receives a signal from the ultra-high-speed A/D module. The load includes a positive or negative excitation lead loop that is in a 180° symmetrical and instantaneous short-circuit state and a rotor shaft.

Abstract: A device and a method for nondestructively detecting a transient characteristic of a conductive screw of a turbo-generator rotor are provided. The device includes a personal computer (PC), an extremely-steep pulse generator, an ultra-high-frequency double-isolation transformer, and a pulse emitting and coupling module, which are connected in sequence. The pulse emitting and coupling module is connected to a load. A synchronous pulse receiving non-inductive divider circuit synchronously receives a characteristic waveform from the load, and the synchronous pulse receiving non-inductive divider circuit is connected to an ultra-high-speed analog/digital (A/D) module through a nonlinear saturation amplifying circuit that amplifies a signal. The PC receives a signal from the ultra-high-speed A/D module. The load includes a positive or negative excitation lead loop that is in a 180° symmetrical and instantaneous short-circuit state and a rotor shaft.

Abstract: A device for inspecting the rotor windings of a generator includes a sequential logic circuit that generates a full-cycle pulse. A high-voltage full-cycle pulse matching generator couples the full-cycle pulse generated by the sequential logic circuit to form a corresponding transient bidirectional rotating magnetic field pulse. The transient bidirectional rotating magnetic field pulse is transmitted to two ends and a large shaft of the generator rotor winding through an impedance-matched connecting line. The transient bidirectional rotating magnetic field pulse generates a resonance effect with each large coil in the rotor. The pulse signal coupling feedback acquisition circuit couples all waveforms reflected by the generator rotor to form a magnetic field waveform, and the magnetic field waveform is transmitted to a data acquisition system by an operational amplifier. A central processing unit transmits a digital information stream to an upper computer.

Abstract: A device for inspecting the rotor windings of a generator includes a sequential logic circuit that generates a full-cycle pulse. A high-voltage full-cycle pulse matching generator couples the full-cycle pulse generated by the sequential logic circuit to form a corresponding transient bidirectional rotating magnetic field pulse. The transient bidirectional rotating magnetic field pulse is transmitted to two ends and a large shaft of the generator rotor winding through an impedance-matched connecting line. The transient bidirectional rotating magnetic field pulse generates a resonance effect with each large coil in the rotor. The pulse signal coupling feedback acquisition circuit couples all waveforms reflected by the generator rotor to form a magnetic field waveform, and the magnetic field waveform is transmitted to a data acquisition system by an operational amplifier. A central processing unit transmits a digital information stream to an upper computer.

Abstract: Methods and compositions are provided for modulating myocyte BK channel activity and for screening for modulators of BK channel activity. The methods and compositions are useful in the treatment of disorders where increasing myocyte BK channel activity can attenuate, revert or prevent the disorder. For example, the methods and compositions are useful for treating disorders ameliorated by increasing vasodilation and blood flow in a subject, in particular, increasing cerebral blood flow.