Abstract: A multi-waveband-tunable multi-scale meta-material and a preparation method and a spectral detection method thereof are provided. The meta-material includes a stretchable layer, a non-stretchable support layer, a metal layer, and a nanoparticle layer sequentially stacked from bottom to top. The stretchable layer is a polydimethylsiloxane (PDMS) layer. The non-stretchable support layer is a polyimide (PI) layer. The metal layer is a gold layer. The nanoparticle layer is modified with a hydrophobic group. The preparation method includes vacuum-evaporating fluorosilane on a silicon wafer, spin-coating PDMS, heat-curing PDMS, conducting plasma cleaning, spin-coating and curing PI, sputtering gold, self-assembling the nanoparticles on a water surface to form the nanoparticle layer, transferring the nanoparticle layer to the metal layer, and etching according to a pattern.

Abstract: A packaging material for the non-destructive detection of food quality, a preparation method of the packaging material, and a detection method using the packaging material are provided. The packaging material includes a film material covering the outside of the food, where the film material includes a flexible base layer, an adhesive layer, a transparent conductive layer, and a nanostructured layer which are sequentially stacked from the outer side to the inner side. The flexible base layer is a polydimethylsiloxane (PDMS) layer. The adhesive layer is a polyimide (PI) layer. The transparent conductive layer is an indium tin oxide (ITO) layer. The nanostructured layer is a silver nanoparticles layer. The preparation method includes spin-coating and curing PI on PDMS, sputtering ITO, self-assembling silver nanoparticles on the transparent conductive layer, and etching according to a pattern.

Abstract: A preparation method a tunable transparent terahertz absorption film for enhancing thermal radiation includes: evaporating/sputtering an indium tin oxide (ITO) on one surface of a polyimide film, transferring graphene to the other surface of the polyimide film, preparing one electrode on the graphene, spin-coating an ionic gel, and preparing the other electrode on the ionic gel to form the tunable transparent terahertz absorption film; and changing bias voltages at two ends of the electrode, acquiring a terahertz time-domain signal of the tunable transparent terahertz absorption film to derive an absorption rate of the tunable transparent terahertz absorption film corresponding to the bias voltages, and placing the tunable transparent terahertz absorption film under sunlight/infrared light to acquire a heating effect. The preparation method utilizes the transparent absorption film of a graphene-polyimide-ITO structure to absorb terahertz waves of multiple bands, improving the heating effect.

Abstract: A method for preparing nanomaterial macroscopic composites through substrate heating and solvent evaporation is provided, and the method includes setting a substrate, and preparing a reaction precursor solution required for the synthesis of nanomaterials; evenly dropping a small volume of the precursor solution on/in the substrate; performing a heating method to make the substrate generate a heat and transferring the heat to the precursor solution on/in the substrate; after a period of time, terminating the heating of the substrate to finish the synthesis, removing and cleaning the substrate, thus obtaining corresponding nanomaterial macroscopic composites.

Abstract: The invention discloses a method for improving triboelectric output performance of a protein film by changing a protein structure. Indissolvable protein powder and a trace amount of another protein powder are co-dissolved in a strong alkaline aqueous solution and maintained for a period of time, and then acidifying treatment is performed to achieve neutral condition to allow charge redistribution to induce refolding of the protein, which results in burying of hydrophobic groups of the protein and exposure of charged groups. Therefore, the solubility of the protein is remarkably improved, and a uniform protein solution is formed under a neutral condition. The plant protein structure is changed through a pH cycle process, a surface group exposure condition is adjusted, and the output performance of the plant protein film is greatly improved.

Abstract: A roller-type conveying device for fruit and vegetable sorting includes a chain assembly and a conveying unit. Fruits and vegetables are placed on the conveying unit. The chain assembly includes a drive chain and a chain support bar, and the drive chain is arranged on the chain support bar. A conveying unit is arranged along a drive chain. The conveying unit includes outer rollers, a roller frame, pin shafts, rubber bushings, a roller shaft, and a support base. The two outer rollers are fixed coaxially on the two ends of the roller shaft. The roller shaft is equipped with the rubber bushing. The roller shaft is movably fitted into a special-shaped hole slot on the top of the roller frame. The roller shaft is arranged axially perpendicular to the transmission direction of the drive chain. The support base is mounted on the drive chain.

Abstract: A triboelectric nanogenerator with slit effect (SE-TENG) and a self-driven wind speed and wind direction sensing device. The TENG includes a wind cavity with slit effect, a triboelectric layer, a hydroxyethyl cellulose (HEC) film, and indium tin oxide (ITO) electrodes. The wind cavity is provided with an inlet end and an outlet end. A layer of the electrode and a triboelectric layer are fixedly adhered to the upper surface and the lower surface of an inner wall of the wind cavity. The wind cavity is provided with a horizontally arranged support bar perpendicular to a wind direction in a middle close to the inlet end. The HEC film includes one end fixedly adhered to the support bar, and the other end extending freely toward the outlet end. The sensing device includes a plurality of SE-TENGs which are fixed on a circumference of a ring. The sensing device can be used in an agricultural environment.

Abstract: A method for extracting Raman characteristic peaks employing improved principal component analysis comprising: using a confocal microscopic Raman-spectroscopic instrument to collect Raman spectroscopic data from surfaces of pork and beef samples; and performing preprocessing on the Raman spectroscopic data, performing principal component analysis, establishing a principal component loading scatter plot, extracting dot characteristics from the principal component loading scatter plot, analyzing same, and performing filtering on the dot characteristics to obtain Raman characteristic peaks. The method for extracting Raman characteristic peaks employing improved principal component analysis is used to extract Raman characteristic peaks from pork and beef samples, and then the Raman characteristic peaks are inputted into a classifier to undergo classification, thereby achieving high accuracy and quick classification.

Abstract: A spectroscopic detection method for detecting a lycopene content in an agricultural product is realized by a spectrometer. The spectrometer includes: a light source device, a convergence device, a chopping device, a filter device, a detection device, and a processing device. The spectroscopic detection method includes: activating the light source device to generate light; converging, by the convergence device, the light generated by the light source device to obtain converged light; controlling and driving the chopping device to obtain detection light used for irradiating an agricultural product and having a modulation frequency; providing the filter device on an optical path of the detection light to obtain characteristic light; controlling the detection device to convert an optical signal of the characteristic light into an electrical signal; and controlling the processing device to output a substance content analysis result according to the electrical signal output by the detection device.

Abstract: The disclosure provides a method for detecting a pomelo flesh mass edible ratio based on X-ray images: acquiring X-ray images A of a pomelo in a vertical direction and a transversal direction; performing noise reduction and grayscale stretching to obtain enhanced X-ray images B; processing the enhanced X-ray images B to obtain vertical and transversal 2D flesh masses; building a prediction model of an actual pomelo flesh mass; inputting the vertical and transversal 2D flesh masses into the prediction model to obtain a predicted flesh mass; weighting a fruit mass of the entire pomelo; and calculating a pomelo fruit edible ratio. The pomelo flesh mass is detected in a non-destructive manner in the disclosure through the combination of X-ray images and image processing technology, so rapid detection that saves time and labor costs is achieved. The accuracy of predicting the pomelo flesh mass is improved.

Abstract: A spectrometer for detecting a trace element in an agricultural product and use thereof is provided. The spectrometer includes: a light source device configured to generate light required by spectroscopic detection; a convergence device configured to converge the light generated by the light source device; a chopping device configured to modulate a frequency of light converged by a convergence device; a filter device configured to shield light of a wavelength other than a preset wavelength; a detection device configured to receive light passing through a to-be-detected agricultural product and the filter device, and convert an optical signal into an electrical signal; and a processing device configured to generate spectroscopic analysis data according to the electrical signal outputted by the detection device and output a substance content analysis result according to the spectroscopic analysis data, where the preset wavelength of the filter device ranges from 400 nm to 5,000 nm.

Abstract: A roller-type conveying device for fruit and vegetable sorting includes a chain assembly and a conveying unit. Fruits and vegetables are placed on the conveying unit. The chain assembly includes a drive chain and a chain support bar, and the drive chain is arranged on the chain support bar. A conveying unit is arranged along a drive chain. The conveying unit includes outer rollers, a roller frame, pin shafts, rubber bushings, a roller shaft, and a support base. The two outer rollers are fixed coaxially on the two ends of the roller shaft. The roller shaft is equipped with the rubber bushing. The roller shaft is movably fitted into a special-shaped hole slot on the top of the roller frame. The roller shaft is arranged axially perpendicular to the transmission direction of the drive chain. The support base is mounted on the drive chain.

Abstract: A triboelectric nanogenerator with slit effect (SE-TENG) and a self-driven wind speed and wind direction sensing device are provided. The TENG includes a wind cavity with slit effect, a triboelectric layer, a hydroxyethyl cellulose (HEC) film, and indium tin oxide (ITO) electrodes. The wind cavity is provided with an inlet end and an outlet end. A layer of the electrode and a triboelectric layer are fixedly adhered to the upper surface and the lower surface of an inner wall of the wind cavity. The wind cavity is provided with a horizontally arranged support bar perpendicular to a wind direction in a middle close to the inlet end. The HEC film includes one end fixedly adhered to the support bar, and the other end extending freely toward the outlet end. The sensing device includes a plurality of SE-TENGs which is fixed on a circumference of a ring.

Abstract: A printed flexible radio frequency identification (RFID) passive temperature-measuring tag based on an MXene ink is provided. At room temperature, an RFID antenna is prepared by printing the MXene ink directly on different flexible substrates through extrusion printing; and an RFID temperature-measuring chip is directly connected to the RFID antenna by using the MXene ink as a binder without an additional metallic ink material such as a conductive silver paste or a binder. The MXene ink of the present disclosure has comparable physical and chemical properties such as high electrical conductivity and mechanical properties to the traditional metallic ink. Compared with an antenna printed by the traditional metallic ink, the printed RFID antenna based on the MXene ink does not require a high-temperature post-treatment after printing, has no restriction on the selection of a flexible substrate, and does not cause heavy metal pollution.

Abstract: A triboelectric nanogenerator (TENG) and a power generation device based on a plant fiber and a modified tribo-electronegative material is provided. A rotor is located inside a stator. An inner circumferential surface of the stator is provided with copper, and an outer circumferential surface of the rotor is provided with a tribo-electronegative material. The tribo-electronegative material is not in contact with the copper, and an air gap is formed between the tribo-electronegative material and the copper. The inner circumferential surface of the stator is further provided with a plant fiber brush. During rotation, the tribo-electronegative material scrapes the plant fiber brush to allow soft contact to transfer charges. The rotor is axially connected to a driving shaft of a waterwheel, and the TENG operates under an action of a water flow. The tribo-electronegative material is obtained by etching a film to form a nano-textured structure and depositing a fluorocarbon layer.

Abstract: A plant protein-based triboelectric nanogenerator (TENG), and a fabrication method and use thereof are provided. The TENG includes a triboelectric negative layer and a protein film, where the protein film and the triboelectric negative layer are stacked surface-to-surface; and an electrode is adhered to or plated on a back surface of each of the protein film and the triboelectric negative layer, or only a back surface of either of the protein film and the triboelectric negative layer is provided with a grounded electrode. A protein powder is dissolved in water or an ethanol aqueous solution, then a plasticizing agent is added, and the protein is denatured through thermal treatment to obtain an extended structure required for film formation; and the solvent is evaporated, and a resulting product is dried to obtain the protein film with uniform texture and excellent transparency and flexibility. The TENG is used in crop growth.

Abstract: In a grain sampling and imaging device, a grain bin (1) is located under a sampling body (5), a grain feed connector (4) is fixed to a top of the sampling body (5), an observation window (2) is installed on the sampling body (5), a camera (3) is installed above the observation window (2); grains fall to a grain feed connector (4), and then into the sampling body (5), and then are sieved by multiple passages of the sampling body (5), a part of the grains randomly enter the observation window (2) and photographed by the camera (3), and finally all of the grains enter the grain bin (1) through a discharge outlet (5.1) provided at a bottom of the sampling body (5).

Abstract: A robot with the perception capability of livestock and poultry information and a mapping approach based on autonomous navigation are disclosed. The robot includes a four-wheeled vehicle (3), an autonomous navigation system, a motion module and an information acquisition module. The autonomous navigation system includes a LiDAR (10), a RGB-D camera (9), an inertial measurement unit (5), an odometer and a main control module (12). The information acquisition module includes two thermal imagers (6), an environmental detection sensor module (8) and a wireless transmission module (11). The robot is controlled in indoor working environment, and simultaneously information about surrounding environment during movement is obtained with the autonomous navigation system; positioning locations are obtained through data processing and a global map is constructed, which can improve positioning accuracy, reduce dependence on breeders, realize automatic environment detection.

Abstract: An integrated flexible self-charging power supply for energy harvesting in an agricultural environment and a preparation method thereof are provided, wherein the integrated flexible self-charging power supply for the energy harvesting in the agricultural environment includes polydimethylsiloxane (PDMS) and a graphene electrode entirely encapsulated in the PDMS, where the graphene electrode includes a power generation portion and an interdigital portion; the power generation portion and the interdigital portion are integrally encapsulated in the PDMS; the interdigital portion is covered with a solid electrolyte; two ends of the interdigital portion of the graphene electrode are led out by wires to serve as two output ends of the power supply.

Abstract: A packaging material for the non-destructive detection of food quality, a preparation method of the packaging material, and a detection method using the packaging material are provided. The packaging material includes a film material covering the outside of the food, where the film material includes a flexible base layer, an adhesive layer, a transparent conductive layer, and a nanostructured layer which are sequentially stacked from the outer side to the inner side. The flexible base layer is a polydimethylsiloxane (PDMS) layer. The adhesive layer is a polyimide (PI) layer. The transparent conductive layer is an indium tin oxide (ITO) layer. The nanostructured layer is a silver nanoparticles layer. The preparation method includes spin-coating and curing PI on PDMS, sputtering ITO, self-assembling silver nanoparticles on the transparent conductive layer, and etching according to a pattern.