Abstract: This application provides a screen casting method and an electronic device, and relates to the field of communication technologies and the field of terminal technologies. A specific solution is as follows: After a first device performs screen casting to a second device, the second device displays a first window; the second device displays first image information from the first device in the first window when the first device is in a screen-on state, where the first image information corresponds to an application interface of a first application in the first device; and after the first device switches to a lock screen state or a screen-off state, the second device displays second image information from the first device in the first window, where the second image information also corresponds to the application interface of the first application in the first device.

Abstract: Embodiments of the present disclosure provide a database processing method and device and a storage medium. The method includes: receiving an operation instruction for a database, and determining whether dictionary-based optimization is enabled for a target column associated with the operation instruction; in response to determining that the dictionary-based optimization is enabled, obtaining a dictionary corresponding to the target column, wherein the dictionary includes a mapping relationship between a value included in the target column and a corresponding replacement value; encoding the target column based on the dictionary to replace the value included in the target column with the corresponding replacement value; and converting, based on the dictionary, the operation instruction into an operation instruction corresponding to the encoded target column, executing the converted operation instruction, and decoding an operation result based on the dictionary.

Abstract: A high-speed precision seed metering device through kinetic-energy-type rotating and throwing and a seed metering control method thereof. Two motors are used to cooperatively control and achieve seed feeding and kinetic-energy-type rotating and throwing seed metering. A seed feeding motor rotates a seed feeding disc to be cooperated with an air suction device to suck seeds, and a throwing motor rotates a seed spoon to fetch seeds. After taking seeds, the seed spoon is accelerated by the throwing motor to provide initial kinetic energy for the seeds. After rotating to a throwing point, the seed spoon is decelerated by the throwing motor to throw the seeds. The throwing speed and the throwing angle of the seeds can be precisely controlled by adjusting the position of the throwing point and the rotational speed of the throwing motor.

Abstract: A high-speed precision seed metering device through kinetic-energy-type rotating and throwing and a seed metering control method thereof are provided. Two motors are used to cooperatively control and achieve seed feeding and kinetic-energy-type rotating and throwing seed metering. A seed feeding motor rotates a seed feeding disc to be cooperated with an air suction device to suck seeds, and a throwing motor rotates a seed spoon to fetch seeds. After taking seeds, the seed spoon is accelerated by the throwing motor to provide initial kinetic energy for the seeds. After rotating to a throwing point, the seed spoon is decelerated by the throwing motor to throw the seeds. The throwing speed and the throwing angle of the seeds can be precisely controlled by adjusting the position of the throwing point and the rotational speed of the throwing motor.

Abstract: Embodiments of this application provide a screen projection method for an electronic device and an electronic device. The method includes: receiving an operation that the electronic device plays back a video, and obtaining a state identifier of the electronic device, where the state identifier indicates whether the electronic device is in a state of system-mirrored screen projection; determining, based on the state identifier, that the electronic device is not in the state of the system-mirrored screen projection; receiving a screen projection operation by a user, and obtaining first device information of a screen projection device; and performing DLNA screen projection from the electronic device to the screen projection device based on the first device information.

Abstract: Embodiments of this application provide a screen projection system and an electronic device. The system includes a first electronic device and a second electronic device, an application message on the first electronic device is streamed to the second electronic device, and a corresponding message notification control is displayed on the second electronic device. The second electronic device receives an operation of a user on the message notification control at first time, and sends a screen projection request to the first electronic device, so that an interface to which the application message corresponds is displayed within a screen projection window of the second electronic device at second time, where the interface includes image information corresponding to the application message. The second time is later than the first time, and the first electronic device is in a lock screen or screen-off state in a time interval between the first time and the second time.

Abstract: The present disclosure relates to a database-based data processing method, device, medium, and apparatus, the method including: receiving a target query statement; determining a corresponding target materialized view for executing the target query statement according to a data query time corresponding to the target query statement and a time granularity of the materialized view in a database, wherein the database is constructed with the materialized view at different time granularities; rewriting the target query statement according to the time granularity of the target materialized view to obtain a plurality of target sub-query statements, wherein the target sub-query statements include sub-query statements which are queried based on the target materialized view; and merging the target sub-query statements, and performing a data query according to a query statement obtained by merging.

Abstract: Embodiments of this application provide a screen projection method for an electronic device and an electronic device. The method includes: receiving an operation that the electronic device plays back a video, and obtaining a state identifier of the electronic device, where the state identifier indicates whether the electronic device is in a state of system-mirrored screen projection; determining, based on the state identifier, that the electronic device is not in the state of the system-mirrored screen projection; receiving a screen projection operation by a user, and obtaining first device information of a screen projection device; and performing DLNA screen projection from the electronic device to the screen projection device based on the first device information.

Abstract: Disclosed is a variable-size and variable-amount topdressing device. The device includes a main frame; an image recognition unit; a variable-amount fertilizer applying portion; two electric push rods which are vertically and fixedly connected to inner opposite surfaces of the main frame respectively; and a variable-size fertilizer applying portion arranged at an output end of the variable-amount fertilizer applying portion, where a height of the variable-size fertilizer applying portion is adjusted by the two electric push rods, an output end of the variable-size fertilizer applying portion is arranged corresponding to the output end of the variable-amount fertilizer applying portion, and the variable-size fertilizer applying portion is used for adjusting a fertilizer applying range. The variable-amount fertilizer applying portion, the variable-size fertilizer applying portion and the two electric push rods are electrically connected to the image recognition unit.

Abstract: Disclosed is a variable-size and variable-amount topdressing device. The device includes a main frame; an image recognition unit; a variable-amount fertilizer applying portion; two electric push rods which are vertically and fixedly connected to inner opposite surfaces of the main frame respectively; and a variable-size fertilizer applying portion arranged at an output end of the variable-amount fertilizer applying portion, where a height of the variable-size fertilizer applying portion is adjusted by the two electric push rods, an output end of the variable-size fertilizer applying portion is arranged corresponding to the output end of the variable-amount fertilizer applying portion, and the variable-size fertilizer applying portion is used for adjusting a fertilizer applying range. The variable-amount fertilizer applying portion, the variable-size fertilizer applying portion and the two electric push rods are electrically connected to the image recognition unit.

Abstract: Various systems are provided for an ultrasound imaging device. In one example, a method comprises instructing a user a location to which to navigate an ultrasound probe in one or more of a horizontal plane and a vertical plane based on a previously acquired first image at a first anatomical location while acquiring a second image at a second, different anatomical location and automatically joining the first and second images together.

Abstract: A method for producing a composite filter tube and filter element made of a multilayer metal mesh and metal powders, including: knitting to obtain metal meshes of different mesh numbers, obtaining a layered structure by means of a lamination method, then putting the layered structure in a vacuum furnace for sintering processing, sintering a metal composite layer to obtain a composite filter sheet and tube made of a multilayer metal mesh and metal powders with a multilayer metal mesh as a structure support layer and a metal powder sinter structure as a filter layer, then rolling the composite filter sheet and tube into a tubular filter element by using a shaping machine, and welding to obtain a composite filter tube and filter element product made of a multilayer metal mesh and metal powders.

Abstract: A method for producing a composite filter tube and filter element made of a multilayer metal mesh and metal powders, including: knitting to obtain metal meshes of different mesh numbers, obtaining a layered structure by means of a lamination method, then putting the layered structure in a vacuum furnace for sintering processing, sintering a metal composite layer to obtain a composite filter sheet and tube made of a multilayer metal mesh and metal powders with a multilayer metal mesh as a structure support layer and a metal powder sinter structure as a filter layer, then rolling the composite filter sheet and tube into a tubular filter element by using a shaping machine, and welding to obtain a composite filter tube and filter element product made of a multilayer metal mesh and metal powders.