Abstract: The present disclosure provides a preparation method of eucalyptol emulsion and application thereof in biopesticides, belonging to the field of emulsion preparation. The method for preparing the eucalyptol emulsion includes the steps of: (1) adding eucalyptol into a cyclodextrin solution to obtain a mixed solution; (2) evenly mixing an emulsifier and a co-emulsifier to obtain a mixed solution; (3) adding the solution obtained in step (2) and water into the solution obtained in step (1), emulsifying to obtain the eucalyptol emulsion. In steps (1), (2) and (3), the mass percents of substances from which the eucalyptol emulsion is prepared are as follows: 0.5%-1% of cyclodextrin, 2.5%-25% of the eucalyptol, 1.25%-15% of the emulsifier, 0.3%-3.75% of the co-emulsifier and 55.3%-95.5% of the water, and the sum thereof is 100%. The emulsion is extremely stable without stratification after being placed at 20° C., 40° C. and 60° C. for 30 days and also has a good insecticidal effect.

Abstract: A zonal bolt-grouting support device and method for cataclastic rock mass large deformation of a high-stress tunnel, the method includes: drill holes in surrounding rock of a tunnel against a tunnel face after rock mass excavation, install high-strength prestressed anchor members, apply a preload to anchor bolts when expansion anchoring agent is fully expanded and has a certain strength, and zonally grout the surrounding rock after stress adjustment. The high-strength prestressed anchor member comprises an anchor bolt, an expansion anchor agent, a decoupling material, a grouting device, a reverse anti-skid device, etc. The grouting device consists of a shallow grouting steel pipe, a deep grouting steel pipe and a grouting stop valve, and the grouting steel pipe is arranged side by side with the anchor bolt in a drill hole. The technical proposal of the invention effectively inhibits the large deformation of a cataclastic rock mass.

Abstract: An active control method and device for large deformation of a deep thin-bedded surrounding rock, the active control method includes: drill holes in the surrounding rock of a tunnel against a tunnel face, add the active control device containing a sleeve, a high-strength prestressed anchor bolt, a resin anchoring agent and a grouting device into drill holes, apply a preload to the anchor bolt when the resin anchoring agent has a certain strength, and carry out lag grouting in the surrounding rock through the grouting device after stress adjustment, and the high-strength prestressed anchor bolt and the grouting device are inserted in the sleeve with holes on the side. The active control device or method of the invention can effectively reduce the fracture depth and degree of a thin-bedded soft rock in deep engineering, and effectively inhibit the occurrence of large deformation disasters.

Abstract: For online audio/video conferencing applications deployed in an open office environment, using shared conference devices, it can be advantageous to define an acoustic fence. A non-participant audio received from outside the acoustic fence can be considered noise and filtered out before transmission of an audio signal to a far end recipient. Three suppression stages are used to filter the non-participant audio. The first suppression stage uses beamformers for suppression. The second suppression stage is mask-based, and the third suppression stage is reference-based. The three suppression stages filter out non-participant audio signals, having a wide range of frequencies.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A rectifier circuit applied in an AC/AC power supply, the rectifier circuit including: a filter circuit configured to receive a DC pulsating voltage, and to generate a supply voltage, where the supply voltage follows the DC pulsating voltage during a first time interval of an operation cycle; and where during a second time interval of the operation cycle, a value of the supply voltage is greater than the value of the supply voltage at an end of the first time interval, in order to reduce a size of the filter circuit.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) and an amplitude ratio of each harmonic component at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller decreases the THD by adjusting a current reference signal according to the measured THD and the amplitude ratio of each harmonic component.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller adjusts an on-time of a main switch of the switching-type regulator based on the measured THD to decrease the THD.

Abstract: A control circuit for a resonant converter, that is configured to: adjust a conduction time of one power switch and a conduction time of one corresponding synchronous rectifier switch in the resonant converter in a resonant period detection mode; control a resonance current to cross zero twice during the conduction time of the synchronous rectifier switch; and obtain a resonant period of the resonant converter.

Abstract: A rectifier circuit applied in an AC/AC power supply, the rectifier circuit including: a filter circuit configured to receive a DC pulsating voltage, and to generate a supply voltage, where the supply voltage follows the DC pulsating voltage during a first time interval of an operation cycle; and where during a second time interval of the operation cycle, a value of the supply voltage is greater than the value of the supply voltage at an end of the first time interval, in order to reduce a size of the filter circuit.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) and an amplitude ratio of each harmonic component at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller decreases the THD by adjusting a current reference signal according to the measured THD and the amplitude ratio of each harmonic component.

Abstract: A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller adjusts an on-time of a main switch of the switching-type regulator based on the measured THD to decrease the THD.

Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: The present invention relates compounds useful as reagents for the diazomethylation reaction, their preparation and the use thereof as reagents in a method for the diazomethylation reaction of aromatic substrates. It relates in particular to a compound of formula (I) wherein E is an electron withdrawing group.

Abstract: The present invention relates compounds useful as reagents for the diazomethylation reaction, their preparation and the use thereof as reagents in a method for the diazomethylation reaction of aromatic substrates. It relates in particular to a compound of formula (I) wherein E is an electron withdrawing group.

Abstract: A power factor correction circuit can include: a power meter configured to measure THD at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust a power factor of an input signal thereof; and a controller configured to generate the switching control signal to control the switching-type regulator to perform power factor correction, where the controller minimizes the THD by adjusting a current reference signal according to a measured THD, and the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.