Abstract: An ultra-wideband electromagnetic band gap (EBG) structure includes multiple EBG units in an array. Each EBG unit includes a power plane, a dielectric substrate and a ground plane from top to bottom. The power plane includes a patch, a coupled complementary split ring resonator (C-CSRR) and a plurality of semi-improved Z-bridge structures. Each edge of the patch is provided with a semi-improved Z-bridge structure. The C-CSRR is provided within a ring formed by the semi-improved Z-bridge structures. The Z-bridge structure includes a first horizontal branch, a first vertical branch, a second horizontal branch and a second vertical branch connected in sequence. The second vertical branch is connected to the patch. First horizontal branches of adjacent EBG units are connected to each other. A circuit board including the aforementioned EBG structure is also provided.

Abstract: Disclosed are an Internet of Things data transmission data and system. The method comprises a downlink transmission step: obtaining first downlink data delivered by an Internet of Things platform; parsing the first downlink data to obtain a target meter of a metering task and a forwarding priority in a first packet; obtaining second downlink data; adding the second downlink data to an asynchronous delivery queue according to the forwarding priority; and delivering the second downlink data to the target meter according to the asynchronous delivery queue, so that the target meter completes the metering task. The present method makes full use of concentrators as intermediate devices while maintaining the integrity of core task data, lowers the channel requirement due to asynchronous execution and is especially suitable for periodic metering tasks.

Abstract: An automatic steering device of an agricultural machine is provided, which is connected with a steering axle of the agricultural machine and comprises: a data acquisition unit for acquiring data information of the agricultural machine, the data information comprises an actual steering angle value, a travelling position and a travelling direction; a driving unit for providing a rotating torque; a steering unit connected with the driving unit and the steering axle and used for transmitting the rotating torque to the steering axle; and a control unit connected with the data acquisition unit and the driving unit, used for obtaining a steering angle value according to the data information of the agricultural machine, and controlling the driving unit according to the steering angle value. The embodiments have simple structure, can be suitable for the agricultural machine with different steering angle ranges, and have high efficiency and simple operation.

Abstract: A method and device are provided for accelerated playback, transmission, and storage of a media file. The method includes acquiring key content in text content of a media file to be played acceleratedly; determining a media file corresponding to the key content; and playing the determined media file.