Abstract: The present disclosure provides a joint control method for nitrogen and phosphorus emissions in farmlands, comprising: reducing nitrogen and phosphorus input during crop sowing or planting by applying composite organic material and chemical fertilizer, wherein the composite organic material comprises: 200-250 parts of edible fungi residues, 300-350 parts of charcoal and 5-10 parts of rhamnolipid; constructing a nitrogen-phosphorus retention layer by utilizing composite microbial agent in combination with 150 parts of edible fungi residues and 20 parts of straw-based hydrogel; constructing a barrier layer by utilizing composite material, and controlling downward leaching of nitrogen and phosphorus that are not absorbed by crops, wherein the composite material of the barrier layer comprises: 25-35 parts of straw-based hydrogel, 20-30 parts of edible fungi residues, 35-55 parts of bentonite and 5-10 parts of corn flour.

Abstract: Provided are a biological floc, a process for the preparation thereof and uses thereof in aquaculture, water purification, industrial water treatment, soil remediation and improvement, and sludge innocent treatment, wherein the biofloc comprises decomposed straw powder, a first microbial agent, a nitrifying bacteria and a denitrifying bacteria, wherein the first microbial inoculant comprises Bacillus subtilis and selective actinomycetes. The process for the preparation of the biological floc comprises firstly adding the microbial agent to the decomposed straw powder, and then successively adding the nitrifying bacteria and the denitrifying bacteria. Further provided is an organic bacterial fertilizer comprising sludge, a biological floc and fermenting bacteria.

Abstract: An embodiment of the present invention provides a digital-to-analog converter including: a primary modulator; a secondary modulator, connected to the primary modulator; a delay unit, connected to the primary modulator; a subtractor, connected to the delay unit and the secondary modulator separately; a first processing module, configured to perform decoding, dynamic matching, and digital-to-analog conversion in sequence on a B-bit digital signal output by the secondary modulator, so as to obtain a first analog signal; a second processing module, configured to perform decoding, dynamic matching, and digital-to-analog conversion in sequence on an (N?B+1) -bit quantization noise signal output by the subtractor, so as to obtain an analog noise signal; and an adder, connected to the first processing module and the second processing module separately, and configured to add the first analog signal and the analog noise signal, so as to obtain and output a second analog signal.

Abstract: A device and a method for eliminating feedback common mode signals are provided, which belong to the electronic technology field. The device includes an operational amplifier circuit with two output ends. The two output ends are a first output end and a second output end. The device also includes a feedback unit. The feedback unit is configured to receive level signals of the first output end and the second output end of the operational amplifier circuit, and superpose feedback common mode signals to input ends of the operational amplifier circuit according to states of the level signals. The method includes: the feedback unit receives level signals of a first output end and a second output end of an operational amplifier circuit, and superposes feedback common mode signals to the input ends of the operational amplifier circuit according to the states of the level signals.

Abstract: A device and a method for eliminating feedback common mode signals are provided, which belong to the electronic technology field. The device includes an operational amplifier circuit with two output ends. The two output ends are a first output end and a second output end. The device also includes a feedback unit. The feedback unit is configured to receive level signals of the first output end and the second output end of the operational amplifier circuit, and superpose feedback common mode signals to input ends of the operational amplifier circuit according to states of the level signals. The method includes: the feedback unit receives level signals of a first output end and a second output end of an operational amplifier circuit, and superposes feedback common mode signals to the input ends of the operational amplifier circuit according to the states of the level signals.