Abstract: A method for preparing an antibacterial and fresh-keeping fruit-packaging material through three-dimensional (3D) printing includes the following steps: dissolving gum arabic and pullulan separately in deionized water to obtain a gum arabic solution and a pullulan solution; subjecting a probiotic to cultivation, centrifugation, and resuspension to obtain a bacterial suspension; mixing the bacterial suspension, the gum arabic solution, and the pullulan solution to obtain a core layer solution; mixing polyvinyl chloride, a modifier, and a plasticizer to obtain a shell layer solution; injecting the shell layer solution and the core layer solution into two syringes, respectively; conducting coaxial 3D printing to finally obtain a coaxial 3D printing product with a core-shell structure; and conducting uniaxial 3D printing with the shell layer solution alone to form an outer layer on the coaxial 3D printing product to obtain the antibacterial and fresh-keeping fruit-packaging material with inner and outer layers.

Abstract: The present invention belongs to the field of organophosphorus pesticide (OP) detection, and relates to a method for detecting an OP by a microfluidic chip based on a fluorescent sensing film. A porous fluorescent sensing film and the microfluidic chip are first constructed. The fluorescent sensing film is fabricated through layer-by-layer self-assembly of a platinum nanoparticle@oxalate-metal-organic framework (MOF) composite and a porous two-dimensional (2D) nanosheet, and has the functions of specifically detecting OPs and blocking macromolecular interferents. The microfluidic chip includes a sample channel, injection channels, reaction tanks, microfluidic channels, a detection tank, and an optical fiber channel, such that sample pretreatment and detection processes are integrated in the chip.

Abstract: The present disclosure belongs to the technical fields of nanoscience and fluorescence sensing, and specifically relates to a preparation method of a paper-based sensor for detecting an ammonia gas, and a use of the paper-based sensor. In the present disclosure, Zn(PA)(BPE) is first prepared, and a porous structure on a surface of the Zn(PA)(BPE) is used to adsorb an ammonia gas to improve a reaction sensitivity of the ammonia gas; then a Zn(PA)@CNQD ratiometric fluorescent substance is prepared from Zn(PA)(BPE) and CNQD through embedding, and finally dissolved in ultrapure water (UPW) to obtain a solution; and the solution is added dropwise on a filter paper, and the filter paper is purged with nitrogen, such that the solution is loaded on the filter paper to obtain a ratiometric fluorescent paper-based sensor.

Abstract: In the present disclosure, a temperature-sensitive inner layer solution, a deformation intermediate layer solution, and a rigid outer layer solution are first prepared and spray-coated layer by layer on a surface of a fruit or vegetable, such that three preservative film layers are produced successively and can be used for the preservation of the fruit or vegetable.

Abstract: The present invention belongs to the field of organophosphorus pesticide (OP) detection, and relates to a method for detecting an OP by a microfluidic chip based on a fluorescent sensing film. A porous fluorescent sensing film and the microfluidic chip are first constructed. The fluorescent sensing film is fabricated through layer-by-layer self-assembly of a platinum nanoparticle@oxalate-metal-organic framework (MOF) composite and a porous two-dimensional (2D) nanosheet, and has the functions of specifically detecting OPs and blocking macromolecular interferents. The microfluidic chip includes a sample channel, injection channels, reaction tanks, microfluidic channels, a detection tank, and an optical fiber channel, such that sample pretreatment and detection processes are integrated in the chip.

Abstract: A photoelectric detection model transfer and sharing method and an Internet of Things monitoring and evaluation system based on a cloud service are provided. The transfer and sharing method includes: invoking a temperature compensation model and a spectrum transfer model to calibrate spectrum information of agricultural product samples, and invoking a detection model to compute the calibrated spectrum information to obtain detection results of the agricultural product samples. The Internet of Things monitoring and evaluation system calibrates spectrum information by using a spectrum transfer and sharing method, invokes a detection model for computing, and returns detection results to a detection terminal in real time, thereby realizing remote monitoring and evaluation of the quality of agricultural products.

Abstract: In the present disclosure, a temperature-sensitive inner layer solution, a deformation intermediate layer solution, and a rigid outer layer solution are first prepared and spray-coated layer by layer on a surface of a fruit or vegetable, such that three preservative film layers are produced successively and can be used for the preservation of the fruit or vegetable.

Abstract: A method for highly-sensitive and rapid detection of a pesticide residue based on an imprinted metal-organic framework (MOF) probe is provided. A molecularly imprinted MOF enzyme-mimic probe is used as a colorimetric probe to catalyze the oxidation of a substrate, thereby enabling a color change of a system; a low-cost filter paper is used as a substrate for supporting the colorimetric probe, including a quality control zone, a standard zone, and a detection zone; in the quality control zone, the optimal colorimetric analysis parameters can be selected according to the temperature, humidity, and light, etc. of an environment to be tested; the standard zone is a standard colorimetric zone obtained through the dropwise addition of standards with different concentrations and is provided to establish a colorimetric analysis mathematical model; and the detection zone is provided for the detection of an actual sample.

Abstract: The present invention relates to the technical field of identification on adulterated meat, and in particular, to a method for identifying raw meat and high-quality fake meat based on a gradual linear array change of a component. The present invention spatially characterizes changing rules of featured components in the meat with the utilization of sensitivities of the visible/near-infrared spectral signals to changes of the components in the meat and the advantage that spectral scanning can acquire optical signals of the samples spatially and consecutively, further constructs the identification model according to differences in components and spectra of a region of interest in the hyperspectral image by taking a derivative for characterizing rates of change of the featured components.

Abstract: The present invention belongs to the technical field of food processing, and in particular, relates to an adaptive quantitative sub-packaging method for fried rice with multiple side dishes in a central kitchen and an apparatus therefor. The present invention mainly includes self-construction of a key side dish recognition model, self-evaluation of the key side dish recognition model, adaptive quantification of batch fried rice, and the apparatus matched with the three-step operation.

Abstract: A color sorting method for small-grain agricultural products combining an area scanning photoelectric characteristic and a line scanning photoelectric characteristic is provided. The present invention obtains an area scan image of small-grain agricultural product materials on a conveyor belt by using an area scan camera, which can accurately extract area array features of the materials and realize accurate identification of the unqualified materials. At the same time, the present invention can provide key parameters for accurate positioning during free falling of the materials while identifying the unqualified materials by using the area scan image, and can cooperate with the line scan positioning camera and the pneumatic nozzle to achieve high-speed elimination of the unqualified materials.

Abstract: A method and a device for detecting plastic foreign objects with low chromaticity difference in shredded tobacco through online pulse spectral imaging are provided. The method includes three steps: negative pressure thin-layer loading of shredded tobacco, pulse line-scanning identification of shredded tobacco, and positive pressure online elimination of foreign objects. Loose shredded tobacco is formed into a fixed and continuous thin layer on a surface of a conveying cylinder under the effect of a negative pressure adsorption force. The surface of the conveying cylinder is coded by areas. An LED linear array light source containing characteristic wavelengths of plastics with low chromaticity difference emits optical pulses, and a line-scanning camera is used to obtain characteristic signals of the plastic foreign objects with low chromaticity difference efficiently in real time.

Abstract: The present invention belongs to the technical field of food processing, and in particular, relates to an adaptive quantitative sub-packaging method for fried rice with multiple side dishes in a central kitchen and an apparatus therefor. The present invention mainly includes self-construction of a key side dish recognition model, self-evaluation of the key side dish recognition model, adaptive quantification of batch fried rice, and the apparatus matched with the three-step operation.

Abstract: A color sorting method for small-grain agricultural products combining an area scanning photoelectric characteristic and a line scanning photoelectric characteristic is provided. The present invention obtains an area scan image of small-grain agricultural product materials on a conveyor belt by using an area scan camera, which can accurately extract area array features of the materials and realize accurate identification of the unqualified materials. At the same time, the present invention can provide key parameters for accurate positioning during free falling of the materials while identifying the unqualified materials by using the area scan image, and can cooperate with the line scan positioning camera and the pneumatic nozzle to achieve high-speed elimination of the unqualified materials.

Abstract: The present disclosure belongs to the technical field of food processing, and in particular relates to a rapid and non-destructive quantitative evaluation method for taste characteristics of fried rice. The method includes three steps: constructing a quantitative model of seasoning for the fried rice, constructing a model for identifying types of materials of the fried rice, and performing quantitative characterization of the taste characteristics of the fried rice. The quantitative model of the seasoning is established based on sensitivity of a spectral signal to changes of the content of seasoning liquid. An analytic equation of key parameters of the quantitative model of the seasoning is established according to characteristics that the total amount of the seasoning in finished fried rice is equal to the total amount of the seasoning added during frying of the fried rice. The quantitative model of the seasoning is rapidly constructed by solving the equations.

Abstract: A method and a device for detecting plastic foreign objects with low chromaticity difference in shredded tobacco through online pulse spectral imaging are provided. The method includes three steps: negative pressure thin-layer loading of shredded tobacco, pulse line-scanning identification of shredded tobacco, and positive pressure online elimination of foreign objects. Loose shredded tobacco is formed into a fixed and continuous thin layer on a surface of a conveying cylinder under the effect of a negative pressure adsorption force. The surface of the conveying cylinder is coded by areas. An LED linear array light source containing characteristic wavelengths of plastics with low chromaticity difference emits optical pulses, and a line-scanning camera is used to obtain characteristic signals of the plastic foreign objects with low chromaticity difference efficiently in real time.

Abstract: The present invention relates to the technical field of identification on adulterated meat, and in particular, to a method for identifying raw meat and high-quality fake meat based on a gradual linear array change of a component. The present invention spatially characterizes changing rules of featured components in the meat with the utilization of sensitivities of the visible/near-infrared spectral signals to changes of the components in the meat and the advantage that spectral scanning can acquire optical signals of the samples spatially and consecutively, further constructs the identification model according to differences in components and spectra of a region of interest in the hyperspectral image by taking a derivative for characterizing rates of change of the featured components.

Abstract: Fluorescent test paper for detecting mercury ions is firstly prepared, the fluorescent test paper including a fluorescence development area and a standard fluorescent colorimetric card. With reference to an excited color corresponding to a reference channel in the standard colorimetric card, the color corresponding to a carbon quantum dots distribution area on the fluorescent test paper is observed to check the fluorescence detection environment during detection with the fluorescent test paper. In colorimetric detection of the content of mercury ions, the concentration of Hg2+ is detected based on an excited color, in the standard colorimetric card, that corresponds to a standard mercury ion sample and is closest to a color signal in a copper nanoclusters distribution area on the fluorescent test paper.

Abstract: Fluorescent test paper for detecting mercury ions is firstly prepared, the fluorescent test paper including a fluorescence development area and a standard fluorescent colorimetric card. With reference to an excited color corresponding to a reference channel in the standard colorimetric card, the color corresponding to a carbon quantum dots distribution area on the fluorescent test paper is observed to check the fluorescence detection environment during detection with the fluorescent test paper. In colorimetric detection of the content of mercury ions, the concentration of Hg2+ is detected based on an excited color, in the standard colorimetric card, that corresponds to a standard mercury ion sample and is closest to a color signal in a copper nanoclusters distribution area on the fluorescent test paper.

Abstract: Disclosed is a bacterial counting method, comprising the following steps, S1: preparing a polyaniline/bacterial composite film on the surface of a glassy carbon electrode by electric polymerization; S2: drawing the standard curve of the polyaniline/bacterial composite film modified electrode; and S3: determining the bacterial concentration of the bacteria solution sample to be tested according to the standard curve obtained in step S2. The method does not require the cultivation of the bacteria in the implementation process, such that same takes a short time and is easy to operate; the method uses aniline as the main reagent, and the consumption of the solution to be tested is small, such that the testing cost is low and the equipment is simple; the method has the advantages of a good repeatability and a wide detection linear range; and the method is an easy to operate, short time-consuming, and low cost bacterial counting method.