Abstract: The present disclosure provides an ecological governance method based on erosion prevention and control for a gentle slope farmland and relates to the technical field of ecological governance of farmlands. The ecological governance method based on erosion prevention and control for a gentle slope farmland includes the following steps: sampling a gentle slope farmland to investigate erosion thereof; and determining erosion of a gentle slope cultivated land and selecting a corresponding recovery strategy based on a detection result of a sample, a soil quality index (SQI), and a comprehensive vegetation quality index (VQI), where the recovery strategy includes a natural recovery method and a biological-farming comprehensive recovery method; enclosing the gentle slope cultivated land, fallowing the gentle slope cultivated land and reducing tillage; exterminating insect pests and poisonous weeds in the enclosed area; and turning over straws under soil by a cultivator. The growth of poisonous weeds is inhibited.

Abstract: Disclosed are a method, device and system for sending a virtual card and a readable storage medium, which are configured to receive at least one audio-video stream data of a plurality of participant terminals in communication connection with a server side; determine target audio-video stream data corresponding to at least one speaker from the at least one audio-video stream data; obtain biological characteristic information for identifying the at least one speaker from the target audio-video stream data, the biological characteristic information includes face characteristic information and/or voiceprint characteristic information; generate a virtual card according to the biological characteristic information; overlay the virtual card to the target audio-video stream data, and synthesize the target audio-video stream data with other audio-video stream data in response to there being a plurality of audio-video stream data into a to-be-sent audio-video stream data; send the to-be-sent audio-video stream data to

Abstract: A device and method for preparing a low-impurity regenerated brass alloy through step-by-step insertion of an electrode are provided. The device includes a melt heating apparatus, an electrode displacement apparatus, and a pulse current generation apparatus. The automatic electrode lifting apparatus is controlled to adjust an insertion depth of the graphite electrode plate in the metal melt, and the pulse current generation apparatus is controlled to adjust the parameters of pulse current to achieve the impurity reduction on the metal melt. The preparation of a low-impurity regenerated brass alloy involves a short production process, simple operations, low energy consumption, and high impurity removal efficiency, and is suitable for regeneration and large-scale continuous production of non-ferrous metal alloys.

Abstract: The present disclosure provides a method and apparatus for extracting a video preview, a device and a computer storage medium. The method comprises: inputting a video into a video classification model obtained by pre-training; obtaining weights of respective video frames output by an attention module in the video classification model; extracting continuous N video frames whose total weight value satisfies a preset requirement, as the video preview of the target video, N being a preset positive integer. It is possible to, in the manner provided by the present disclosure, automatically extract continuous video frames from the video as the video preview, without requiring manual clipping, and with manpower costs being reduced.

Abstract: An ambient light filter configured to filter ambient light noises from an optical current that is at least partially caused by an optical pulse sequence emitted by a light emitting device, can include: a sample and detection circuit configured to sample the optical current and to obtain a current component in a first mode, and to remove the current component from the optical current and to generate a detection signal in a second mode; a current amplifier configured to receive the detection signal, and to generate an amplified current signal; and a control circuit configured to switch the sample and detection circuit between the first and second modes, where the control circuit switches the sample and detection circuit to the first mode in at least one optical pulse gap, and switches the sample and detection circuit to the second mode when a next optical pulse arrives.

Abstract: The present disclosure provides a video displaying method and apparatus, a device and a computer storage medium, wherein the method comprises: positioning a target video; displaying a video preview of the target video, the video preview being a video segment extracted from the target video. This displaying manner exhibits a stronger capability of expressing the video content. The user can better know whether the video is the desired content. The present disclosure may reduce a probability of the user missing desired video resources and reduce a probability that the user finds that the video content does not meet an expectation after he views the video content, thereby helping the user to conveniently and effectively view the desired video resources.

Abstract: A photoelectric sensor can include: a lighting element configured to generate a first optical signal, where a second optical signal is generated by reflection of the first optical signal when emitting an object; a driving circuit configured to drive the lighting element; a photoelectric conversion circuit configured to generate a first optical current in accordance with the second optical signal; and a programmable current amplifier circuit configured to sample and hold the first optical current when the lighting element is in operation, and to generate a second optical current when the lighting element is out of operation in one detection period, where the second optical current lasts for at least one working period in the detection period, and where the second optical current represents the first optical current.

Abstract: The present disclosure provides a video displaying method and apparatus, a device and a computer storage medium, wherein the method comprises: positioning a target video; displaying a video preview of the target video, the video preview being a video segment extracted from the target video. This displaying manner exhibits a stronger capability of expressing the video content. The user can better know whether the video is the desired content. The present disclosure may reduce a probability of the user missing desired video resources and reduce a probability that the user finds that the video content does not meet an expectation after he views the video content, thereby helping the user to conveniently and effectively view the desired video resources.

Abstract: The present disclosure provides a method and apparatus for extracting a video preview, a device and a computer storage medium. The method comprises: inputting a video into a video classification model obtained by pre-training; obtaining weights of respective video frames output by an attention module in the video classification model; extracting continuous N video frames whose total weight value satisfies a preset requirement, as the video preview of the target video, N being a preset positive integer. It is possible to, in the manner provided by the present disclosure, automatically extract continuous video frames from the video as the video preview, without requiring manual clipping, and with manpower costs being reduced.

Abstract: A photo detector can include: a light emitting device configured to emit light; a driving circuit configured to drive the light emitting device; a photo-electric conversion circuit configured to generate an optical current signal according to an optical signal; an isolation circuit configured to transmit the optical current signal in an isolated manner; an ambient light filter configured to filter a current component of the optical current signal corresponding to an ambient light, and to generate a clean optical current signal; a current amplification circuit configured to amplify the clean optical current signal, and to generate an amplified optical current signal; (vii) an analog-to-digital converter configured to convert the amplified optical current signal to a digital signal; and a control circuit configured to output an optical detection signal according to the digital signal.

Abstract: An ambient light filter configured to filter ambient light noises from an optical current that is at least partially caused by an optical pulse sequence emitted by a light emitting device, can include: a sample and detection circuit configured to sample the optical current and to obtain a current component in a first mode, and to remove the current component from the optical current and to generate a detection signal in a second mode; a current amplifier configured to receive the detection signal, and to generate an amplified current signal; and a control circuit configured to switch the sample and detection circuit between the first and second modes, where the control circuit switches the sample and detection circuit to the first mode in at least one optical pulse gap, and switches the sample and detection circuit to the second mode when a next optical pulse arrives.

Abstract: A photo detector can include: a light emitting device configured to emit light; a driving circuit configured to drive the light emitting device; a photo-electric conversion circuit configured to generate an optical current signal according to an optical signal; an isolation circuit configured to transmit the optical current signal in an isolated manner; an ambient light filter configured to filter a current component of the optical current signal corresponding to an ambient light, and to generate a clean optical current signal; a current amplification circuit configured to amplify the clean optical current signal, and to generate an amplified optical current signal; (vii) an analog-to-digital converter configured to convert the amplified optical current signal to a digital signal; and a control circuit configured to output an optical detection signal according to the digital signal.

Abstract: A photoelectric sensor can include: a lighting element configured to generate a first optical signal, where a second optical signal is generated by reflection of the first optical signal when emitting an object; a driving circuit configured to drive the lighting element; a photoelectric conversion circuit configured to generate a first optical current in accordance with the second optical signal; and a programmable current amplifier circuit configured to sample and hold the first optical current when the lighting element is in operation, and to generate a second optical current when the lighting element is out of operation in one detection period, where the second optical current lasts for at least one working period in the detection period, and where the second optical current represents the first optical current.