Abstract: Disclosed are a dihydropyrimidine compound, a preparation method therefor and an application thereof. Specifically, disclosed are a dihydropyrimidine compound represented by formula 1? or a pharmaceutically acceptable salt thereof, a composition comprising the compound, and an application of the compound in preparing a drug for treating and preventing hepatitis B virus (HBV) infection related diseases. The disclosed dihydropyrimidine compound can effectively suppress the activity of HBV in HepG2.2.15 cells, and is less toxic to liver cancer cells.

Abstract: Disclosed are a phase-tracked pulse generation circuit and a power supply device. The present application uses a driving pulse rising edge of a power supply as a reference, and uses a constant current circuit to charge a charging and discharging circuit at a constant current. When the reference driving pulse rising edge comes, the charging and discharging circuit is discharged; the peak voltage on the charging and discharging circuit is taken out and then divided for comparison with the voltage on the charging and discharging circuit; when the voltage on the charging and discharging circuit is equal to a divided voltage value of the peak voltage, the output of a comparison circuit turns high, and the output of a comparator is the phase-tracked pulse; the rising edge of the phase-tracked pulse can be used for synchronizing another power supply.

Abstract: Disclosed are a phase-tracked pulse generation circuit and a power supply device. The present application uses a driving pulse rising edge of a power supply as a reference, and uses a constant current circuit to charge a charging and discharging circuit at a constant current. When the reference driving pulse rising edge comes, the charging and discharging circuit is discharged; the peak voltage on the charging and discharging circuit is taken out and then divided for comparison with the voltage on the charging and discharging circuit; when the voltage on the charging and discharging circuit is equal to a divided voltage value of the peak voltage, the output of a comparison circuit turns high, and the output of a comparator is the phase-tracked pulse; the rising edge of the phase-tracked pulse can be used for synchronizing another power supply.

Abstract: A ventilated tent includes a tent cloth, a tent frame, a cloth rope and a buttonhole; the tent cloth is set on the tent frame fixedly connected with the tent frame; the tent cloth includes a top cloth, a front cloth, a back cloth, a left side cloth and a right side cloth; left and right ends of the top cloth cover top of the left side cloth and the right side cloth; the buttonhole is fixed at an edge of the tent cloth, the cloth rope connects the top end of the left side cloth and the top end of the right side cloth through the buttonhole, and a ventilation gap is formed when top end of the left side cloth and right side cloth go away from left end and tight end of the top cloth by tightening and relaxing the cloth rope.

Abstract: A ventilated tent includes a tent cloth, a tent frame, a cloth rope and a buttonhole; the tent cloth is set on the tent frame fixedly connected with the tent frame; the tent cloth includes a top cloth, a front cloth, a back cloth, a left side cloth and a right side cloth; left and right ends of the top cloth cover top of the left side cloth and the right side cloth; the buttonhole is fixed at an edge of the tent cloth, the cloth rope connects the top end of the left side cloth and the top end of the right side cloth through the buttonhole, and a ventilation gap is formed when top end of the left side cloth and right side cloth go away from left end and tight end of the top cloth by tightening and relaxing the cloth rope.