Abstract: The disclosure discloses a polycrystalline diamond composite sheet having a continuous gradient transition layer and a 3D printing preparation method thereof. The polycrystalline diamond composite sheet consists of a polycrystalline diamond layer, a continuous gradient transition layer, and a cemented carbide substrate from top to bottom, in which the continuous gradient transition layer consists of diamond and cemented carbide. Along a direction from the cemented carbide substrate to the polycrystalline diamond layer, a content of the cemented carbide in the continuous gradient transition layer decreases from 100% to 0, and a content of the diamond increases from 0 to 100%. By designing and combining the continuous gradient transition layer with 3D printing technology, the disclosure realizes a continuous change in the two materials of diamond and cemented carbide, thereby eliminating the sudden change interface of the materials inside the diamond composite sheet.

Abstract: The disclosure discloses a polycrystalline cubic boron nitride composite sheet having a continuous gradient structure and a preparation method thereof. The polycrystalline cubic boron nitride composite sheet consists of a cemented carbide substrate, a continuous gradient layer, and a CBN layer from bottom to top. The continuous gradient layer contains cemented carbide and CBN, a content of CBN increases in continuous gradient from bottom to top, while a content of the cemented carbide decreases in continuous gradient from bottom to top. A volume fraction D of CBN and a volume fraction M of cemented carbide in the continuous gradient layer both satisfy exponential gradient functions. At the same time, the disclosure uses direct ink writing 3D printing technology with slurry to realize the preparation of the polycrystalline cubic boron nitride composite sheet having the continuous gradient structure.

Abstract: Disclosed are an active equalization system and equalization method for a battery. The system includes a main control unit, a charging control unit and a discharging control unit. The main control unit is configured to receive an equalization charging instruction/equalization discharging instruction sent by an upper computer, send a first signal to the charging control unit according to the equalization charging instruction, and send a second signal to the discharging control unit according to the equalization discharging instruction. The charging control unit is configured to receive the first signal sent by the main control unit, and control the PWM startup and shutdown state of the charging MOS transistor according to the first signal. The discharging control unit is configured to receive the second signal sent by the main control unit, and control the PWM startup and shutdown state of the discharging MOS transistor according to the second signal.

Abstract: The disclosure relates to a polycrystalline diamond composite sheet having a ripple-shaped gradient layer and a preparation method thereof. The polycrystalline diamond composite sheet consists of a cemented carbide substrate, a ripple-shaped gradient layer of a multi-layer structure, and a polycrystalline diamond layer from bottom to top. In the ripple-shaped gradient layer, a content of polycrystalline diamond increases from bottom to top, and a content of cemented carbide decreases from bottom to top. In the ripple-shaped gradient layer, an amplitude of a ripple-shaped structure is 0.2 to 0.6 mm, a wavelength is 1 to 2 mm, a spacing between an upper ripple and a lower ripple of a top layer is set to a gradient of (t/2 to t) mm to t mm from a peak to a trough, and spacings between an upper ripple and a lower ripple of remaining layers are all t mm, wherein t is 0.05 to 0.4.

Abstract: The disclosure provides a gradient structure cubic boron nitride composite sheet and a preparation method thereof. The gradient structure cubic boron nitride composite sheet consists of a cemented carbide substrate, a gradient transition layer, and a CBN layer from bottom to top. The gradient transition layer consists of N gradient layers, and the N is 4 to 18. From bottom to top, there are sequentially a first gradient layer, a second gradient layer, an Nth gradient layer, and so on. Any of the gradient layers consists of CBN and cemented carbide, in which the volume fraction of the cemented carbide in the Nth layer is 5 to 30% less than the volume fraction of the cemented carbide in the N?1th layer, and the volume fraction of the CBN in the Nth layer is 5 to 30% more than the volume fraction of the CBN in the N?1th layer.

Abstract: An oscillating fluidic pressure pulse generator, includes: an outer tube, an upper connector, a lower connector and a vortex fluidic oscillator. A first central fluid channel and a second central fluid channel are respectively formed in the upper connector and the lower connector, two ends of the outer tube are respectively connected to the upper connector and the lower connector through a screw thread, and the vortex fluidic oscillator is provided in the outer tube and abuts against the upper connector and the lower connector; and the vortex fluidic oscillator is provided with an inlet and connected to a fluidic oscillating chamber, two flow guiding blocks are arranged below the fluidic oscillating chamber, a vortex chamber inlet is formed between the two flow guiding blocks, two control channels are respectively formed outside the two flow guiding blocks, a vortex chamber is provided below the vortex chamber inlet.