Abstract: A resonant converter has a first transistor, a second transistor, a third transistor, a fourth transistor, a transformer, a resonant tank, a rectifier circuit and a current sensing circuit. The transformer comprises a primary winding and a first sampling winding at a primary side, and a secondary winding at a secondary side. The resonant tank circuit is coupled between the first switching node and the second switching node and comprises a resonant capacitor, a resonant inductor and a magnetizing inductance of the primary winding coupled in series. The rectifier circuit is coupled between the first end of the secondary winding and the second end of the secondary winding. The current sensing circuit is used to receive the first capacitor voltage sampling signal and provide a current sensing signal based on the first capacitor voltage sampling signal.

Abstract: A gas-sensitive material, a preparation method therefore and an application thereof, and a gas sensor using the gas-sensitive material are provided. The gas-sensitive material is a carbon material-metal oxide composite nanomaterial formed by compounding a carbon material and metal oxides. The content of the carbon material is 0.5˜20 wt. % and the content of the metal oxides is 80˜99.5 wt. %; the metal oxides contain tungsten oxide and one or more selected from tin oxide, iron oxide, titanium oxide, copper oxide, molybdenum oxide, and zinc oxide; the metal oxides are formed on the carbon material in the form of nanowires, and the nanowires are tungsten oxide-doped nanowires. The gas-sensitive material has reduced resistance, is capable of responding to various gases at a reduced working temperature.

Abstract: Provided is a method of reconstructing multi-source long-time-series night light data and a system thereof, relating to the field of reconstructing ecological remote sensing data. Based on night light images of a first-generation satellite DMSP/OLS (Defense Meteorological Satellite Program/Operational Line-scan System) and a second-generation satellite NPP/VIIRS (National Polar-orbiting Partnership/Visible Infrared Imaging Radiometer Suite), a method of reconstructing a set of long-time-series night light data products is developed. Since satellite images that two generations of satellites have at the same time in a certain year use an inverse hyperbolic sine transform to fit NPP/VIIRS in 2013 into a data form of DMSP/OLS, and obtain an optimal fitting equation, thus producing a set of long-time-series data products from 1992 to 2021. The method can solve a fault problem between two generations of light data of DMSP/OLS and NPP/VIRS, and improve the accuracy of data reconstruction.

Abstract: A communication method, a communication apparatus, an electronic device, and a computer-readable storage medium. The present disclosure can coordinate member devices connected with a cross-domain device, thereby improving the flexibility of communication connections between member devices in multiple device domains and the cross-domain device.

Abstract: The present disclosure provides a parameter design method for a series passive impedance adapter applicable to a VSC-HVDC transmission system, to resolve the technical problem that high-frequency resonance may occur when impedance of a VSC-HVDC transmission system is mismatched with that of a sending-end or receiving-end grid. A parameter design goal of the present disclosure is that reactive power consumed by a series passive impedance adapter is not more than A times rated power of a converter, and a loss of the series passive impedance adapter in a fundamental wave is B times the rated power of the converter. The parameter design method for a series passive impedance adapter applicable to a VSC-HVDC transmission system in the present disclosure can realize a positive impedance characteristic within a concerned frequency band and completely eliminate a risk of harmonic resonance.

Abstract: A microreactor has a plurality of mixing units connected in sequence. Each of the mixing units has a housing in which a flow chamber is formed. An inlet portion and an outlet portion formed on two opposite ends of each mixing unit along the longitudinal direction, respectively, are in communication with the flow chamber. The mixing unit also has a first blocking portion centrally arranged within said flow chamber along a lateral direction perpendicular to the longitudinal direction, and between the inlet portion and the outlet portion, so that a first advancing passage, a second advancing passage and a mixing region are formed within the flow chamber. At downstream ends of said first passage and said second advancing passage, the microreactor is further provided with auxiliary flow-guiding portions protruding from a first side profile and a second side profile respectively and extending towards but spaced apart from each other.

Abstract: A resonant converter has a primary resonant tank circuit and a secondary resonant tank circuit. An inverter circuit converts an input DC voltage received by the resonant converter at an input voltage node to a pulsating signal that is fed to the primary resonant tank circuit to generate a resonant tank current that flows through a primary winding of a transformer. The resonant tank current induces current in a secondary winding of the transformer. The induced current is rectified by a rectifier and the rectified signal is filtered to generate an output DC voltage at an output voltage node. The secondary resonant tank circuit is disposed between the secondary winding of the transformer and the output voltage node, and a tank node of the secondary resonant tank is connected to the primary resonant tank circuit through the inverter circuit.

Abstract: Described are a water quality testing method and a water quality testing apparatus. The testing method includes: obtaining, in a first environment, a testing sample including a target testing object; selecting a reference object according to the testing sample, and respectively acquiring the chroma of the reference object in a second environment and in the first environment; constructing a correction model according to the chroma of the reference object in the second environment and in the first environment; obtaining the chroma of the testing sample in the first environment; according to the chroma of the testing sample in the first environment and the correction model, obtaining the chroma of the testing sample in the second environment; and according to a preset standard curve and the chroma of the testing sample in the second environment, obtaining the concentration of the target testing object in the testing sample.

Abstract: The present disclosure provides a parameter design method for a series passive impedance adapter applicable to a VSC-HVDC transmission system, to resolve the technical problem that high-frequency resonance may occur when impedance of a VSC-HVDC transmission system is mismatched with that of a sending-end or receiving-end grid. A parameter design goal of the present disclosure is that reactive power consumed by a series passive impedance adapter is not more than A times rated power of a converter, and a loss of the series passive impedance adapter in a fundamental wave is B times the rated power of the converter. The parameter design method for a series passive impedance adapter applicable to a VSC-HVDC transmission system in the present disclosure can realize a positive impedance characteristic within a concerned frequency band and completely eliminate a risk of harmonic resonance.

Abstract: A power module has a substrate, a magnetic component disposed on the substrate, a plurality of power integrated circuits (ICs), and a heat spreader. The heat spreader and at least a part of the plurality of power ICs are disposed on a top surface of the substrate. The heat spreader is fixed on the substrate through a structural adhesive, covering top surfaces of the part of the plurality of power ICs on the top surface of the substrate, and is in contact with the top surfaces of the part of the plurality of power ICs on the top surface of the substrate through a thermal conductive adhesive. A difference between a height measured from a topmost surface of the magnetic component to the top surface of the substrate and a height measured from a topmost surface of the heat spreader to the top surface of the substrate is within 300 um.

Abstract: A resonant converter has a primary resonant tank circuit and a secondary resonant tank circuit. An inverter circuit converts an input DC voltage received by the resonant converter at an input voltage node to a pulsating signal that is fed to the primary resonant tank circuit to generate a resonant tank current that flows through a primary winding of a transformer. The resonant tank current induces current in a secondary winding of the transformer. The induced current is rectified by a rectifier and the rectified signal is filtered to generate an output DC voltage at an output voltage node. The secondary resonant tank circuit is disposed between the secondary winding of the transformer and the output voltage node, and a tank node of the secondary resonant tank is connected to the primary resonant tank circuit through the inverter circuit.

Abstract: A resonant converter has a primary resonant tank circuit and a secondary resonant tank circuit. An inverter circuit converts an input DC voltage received by the resonant converter at an input voltage node to a pulsating signal that is fed to the primary resonant tank circuit to generate a resonant tank current that flows through a primary winding of a transformer. The resonant tank current induces current in a secondary winding of the transformer. The induced current is rectified by a rectifier and the rectified signal is filtered by an output capacitor to generate an output DC voltage at an output voltage node. The secondary resonant tank circuit is disposed between the input voltage node and the output voltage node to inject odd order harmonics of the operating frequency to the primary tank circuit to shape the resonant tank current.

Abstract: A method of preparing epoxypropane by direct epoxidation of propylene includes the steps of contacting a mixed gas consisting of a reaction feed gas and a diluent gas with a catalyst to carry out reaction under reaction conditions of propylene epoxidation to prepare epoxypropane. The reaction feed gas contains propylene, oxygen gas and hydrogen gas while at least a portion of the diluent gas is a gaseous olefin. Using gaseous olefin as at least a portion of the diluent gas to perform propylene epoxidation that can significantly extend service life of the catalyst, effectively reduce the used amount of diluent gas, and improve the reaction selectivity and propylene conversion rate.

Abstract: A hybrid DC-DC converter includes a converter circuit, a bridge circuit with a bridge path that includes a winding of a transformer, and another bridge circuit with a bridge path that includes another winding of the transformer. Current through the bridge path of the other bridge circuit flows through the converter circuit in one direction and bypasses the converter circuit in the other direction. The converter circuit can operate in buck, boost, or buck-boost mode.

Abstract: An LLC resonant converter including a transformer, a switching full-bridge circuit, a resonant circuit, and a bridge rectifier. The switching full-bridge circuit has a first pair of switches and a second pair of switches, with the first pair of switches being connected between a DC input voltage and a second end of a secondary winding of the transformer, the second pair of switches being connected between a DC input voltage and a first end of the secondary winding of the transformer.

Abstract: A gas-sensitive material, a preparation method therefore and an application thereof, and a gas sensor using the gas-sensitive material are provided. The gas-sensitive material is a carbon material-metal oxide composite nanomaterial formed by compounding a carbon material and metal oxides. The content of the carbon material is 0.5˜20 wt. % and the content of the metal oxides is 80˜99.5 wt. %; the metal oxides contain tungsten oxide and one or more selected from tin oxide, iron oxide, titanium oxide, copper oxide, molybdenum oxide, and zinc oxide; the metal oxides are formed on the carbon material in the form of nanowires, and the nanowires are tungsten oxide-doped nanowires. The gas-sensitive material has reduced resistance, is capable of responding to various gases at a reduced working temperature.

Abstract: An LLC resonant converter including a transformer, a switching full-bridge circuit, a resonant circuit, and a bridge rectifier. The switching full-bridge circuit has a first pair of switches and a second pair of switches, with the first pair of switches being connected between a DC input voltage and a second end of a secondary winding of the transformer, the second pair of switches being connected between a DC input voltage and a first end of the secondary winding of the transformer.

Abstract: An LLC resonant converter includes a transformer, a switching half-bridge circuit, a resonant circuit, and a full-bridge rectifier. Both the switching half-bridge circuit and the full-bridge rectifier are on the same side of the transformer. The switching half-bridge circuit has a pair of switches, with one of the switches being connected to the output voltage node of the converter.

Abstract: In one example, a planar omnidirectional wireless power transfer system includes high frequency power generator configured to generate a supply of high frequency oscillating power, a number of transmitter-side resonant tank circuits electrically coupled to the high frequency power generator, a planar coil arrangement including a number of coils arranged for omnidirectional power transfer to a device placed over the planar coil arrangement, and a controller configured to activate individual ones of the transmitter-side resonant tank circuits to wirelessly transmit power to the device. In one aspect, the controller can activate individual ones of the transmitter-side resonant tank circuits over time to generate an omnidirectional field distribution for wireless power transmission.

Abstract: A hybrid DC-DC converter includes a converter circuit, a bridge circuit with a bridge path that includes a winding of a transformer, and another bridge circuit with a bridge path that includes another winding of the transformer. Current through the bridge path of the other bridge circuit flows through the converter circuit in one direction and bypasses the converter circuit in the other direction. The converter circuit can operate in buck, boost, or buck-boost mode.