Abstract: A method for evaluating energy efficiency of electric arc furnace steelmaking comprises: obtaining original smelting information of the electric arc furnace; processing the original smelting information, and calculating an electrical energy efficiency evaluation index and a chemical energy efficiency evaluation index for process operation; wherein the electrical energy efficiency evaluation index comprises circuit efficiency, transformer tap capacity utilization rate and electrical energy thermal efficiency, and the chemical energy efficiency evaluation index comprises oxygen utilization rate, carbon powder utilization rate and chemical energy thermal efficiency; and evaluating an energy utilization condition of the electric arc furnace comprehensively based on the electrical energy efficiency evaluation index and the chemical energy efficiency evaluation index.

Abstract: The present disclosure provides a loudspeaker assembly and an electronic device, relating to the technical field of electronic devices, so as to solve the problems of single sound effect and lack of good sound effect. The loudspeaker assembly includes a first housing, a second housing, a loudspeaker vibrator and an adjusting mechanism. The first housing and the loudspeaker vibrator form a first cavity, and the second housing and the loudspeaker vibrator form a second cavity. The adjusting mechanism includes a driving mechanism and a filling part. The driving mechanism drives the filling part to move, so as to change the volume of the filling part extending into the second cavity.

Abstract: A double Schottky-barrier diode includes a semi-insulating substrate, a left mesa formed by growth and etching on the semi-insulating substrate, a middle mesa formed by growth and etching on the semi-insulating substrate, a right mesa formed by growth and etching on the semi-insulating substrate, two anode probes and two air-bridge fingers. The two Schottky contacts are closely fabricated on the same mesa (middle mesa) in a back-to-back manner to obtain even symmetric C-V characteristics and odd symmetric I-V characteristics from the device level. The output of a frequency multiplier fabricated using the double Schottky-barrier diode only has odd harmonics, but no even harmonics, which is suitable for the production of high-order frequency multipliers. The cathodes of the two Schottky contacts are connected by the buffer layer without ohmic contact.

Abstract: A parameter extraction method for quasi-physical large-signal model for microwave gallium nitride high-electron-mobility transistors (GaN HEMTs). The method includes: 1) acquiring a data set of parameters for a large-signal model for a plurality of different microwave transistors GaN HEMTs having the same size; 2) performing statistical analysis of physical parameters of the large-signal model and sub-models thereof: 3) characterizing the correlation between the physical parameters by factor analysis; and 4) predicting the output characteristics of the GaN HEMTs.

Abstract: A double Schottky-barrier diode includes a semi-insulating substrate, a left mesa formed by growth and etching on the semi-insulating substrate, a middle mesa formed by growth and etching on the semi-insulating substrate, a right mesa formed by growth and etching on the semi-insulating substrate, two anode probes and two air-bridge fingers. The two Schottky contacts are closely fabricated on the same mesa (middle mesa) in a back-to-back manner to obtain even symmetric C-V characteristics and odd symmetric I-V characteristics from the device level. The output of a frequency multiplier fabricated using the double Schottky-barrier diode only has odd harmonics, but no even harmonics, which is suitable for the production of high-order frequency multipliers. The cathodes of the two Schottky contacts are connected by the buffer layer without ohmic contact.

Abstract: A statistical analysis method for technological parameters of GaN devices based on equivalent circuit model is provided. The analysis method includes the following steps: establishing a GaN device small-signal equivalent circuit model, and extracting small-signal model parameters; establishing a GaN device large-signal equivalent circuit model, and extracting large-signal model parameters; tuning and optimizing the large-signal model parameters by targeting the measured microwave characteristics of the device; and extracting technological parameters of GaN devices in multiple batches based on the established large-signal model, and statistically analyzing the technological parameters.