49results about "Nitrogen determination" patented technology

The invention discloses a hyperspectral technology-based inversion method for SPAD values and nitrogen concentrations of leaves in the whole growth period of rice. The hyperspectral data of the leaves of the rice are obtained by means of an ASD Field Spec4 portable ground object spectrometer in the initial differentiation period (PI), the heading period (HD), the middle filling period (MF) and the mature period (MA) of young ears; measuring the SPAD value of the rice as the chlorophyll content by using an SPAD-502 chlorophyll meter; determining the nitrogen concentration of the rice leaves by adopting a Kjeldahl method; performing correlation analysis on the hyperspectral data of the leaves, the nitrogen concentration and SPAD, and screening sensitive wavebands. According to the method, the hyperspectral characteristic wave band of the rice leaf is extracted through a correlation analysis method, so that the redundancy of full-spectrum data modeling is reduced, data are optimized, an inversion model of the nitrogen concentration and SPAD value of the rice leaf is constructed based on linear regression (LR), random forest (RF), support vector regression (SVR) and gradient boosting (GBRT), and the nitrogen concentration and SPAD value of the rice leaf are obtained. The optimal machine learning algorithm with high precision and good stability is obtained, and a scientific basis can be provided for non-destructive real-time leaf color monitoring and precise fertilization control of indica rice in the South China.

The invention provides a hyperspectrum-based tea tree canopy leaf nitrogen estimation method, which comprises the following steps of: firstly, smoothing original spectral data of a tea tree canopy by using a Savitzky-Golay method so as to reduce random noise and improve a signal-to-noise ratio; then, the original spectrum is converted into 600 wave bands at the interval of 1 nm through spline interpolation, so that the continuity and convenience of calculation are ensured; the method comprises the following steps of: firstly, carrying out first-order derivative processing on a spectrum, then carrying out second-order derivative processing on the processed spectrum, calculating a normalized difference spectrum index (NDSI) by using a derivative spectrum, calculating a Pearson's correlation coefficient (PCC) between the NDSI and a measured nitrogen element, carrying out principal component analysis (PCA) on the highest 20 indexes of the correlation coefficient, and finally constructing a multiple linear regression model by using the principal components with the first 10 PCA scores as parameters. The method is used for predicting the nitrogen content (LNC) of tea tree canopy leaves. Prediction experiments of a plurality of tea gardens show that the model shows a good prediction effect which is close to the actual nitrogen content, and the generalization performance is good.

The invention provides a method and a system for evaluating the biological health condition of cultivated land soil based on exploratory factor analysis, and relates to the technical field of evaluation of the biological health condition of soil. The precise analysis of the complex interaction relationship between the soil microorganism function and the environmental factor is realized; through multi-dimensional index fusion and deep mining of a factor model, key biological function factors are effectively discriminated and quantified, and the scientific evaluation capability of soil ecological functions is improved; in combination with causal path analysis, the scheme can reveal the influence of environmental pressure on a microbial regulation and control mechanism, and intelligent attribution and traceability of abnormal health conditions are realized; based on dynamic fusion and grading judgment of function and environment scores, the scheme supports accurate health condition evaluation and hierarchical intervention, the early warning capability and decision scientificity of soil management are enhanced, and the agricultural sustainable development guarantee level is remarkably improved.

The invention discloses a method for detecting the nitrogen content of organ tissues of different varieties of oilseed rapes based on visible near-infrared spectroscopy, which comprises the following steps: firstly, collecting oilseed rape leaf, shell, stalk and root system samples under the conditions of multiple varieties and multiple nitrogen fertilizer levels, and acquiring spectral data within the range of 430-2500nm by using a visible near-infrared spectroscopy; and a Kjeldahl method is synchronously adopted to measure the real nitrogen content as a reference value. Preprocessing the spectral data, including de-noising, standard normal variable transformation, multivariate scatter correction and derivative processing, so as to weaken the influence of scattering and baseline drift; characteristic wavelengths related to the nitrogen content are screened through stepwise regression, variable projection importance, competitive self-adaptive reweighted sampling, a continuous projection algorithm and other methods, and a random forest model, a support vector machine model, a partial least squares discriminant analysis model, a partial least squares regression model, a support vector regression model, an XGBoost model and other models are combined. And respectively constructing a classification identification model and a regression prediction model.

The invention belongs to the technical field of diesel engine emission reduction, and particularly relates to a diesel engine nitrogen oxide reducing agent PN emission characteristic test system and test method. The diesel engine nitrogen oxide reducing agent PN emission characteristic test system comprises a combustor, a filter, a mixing pipe, an SCR catalyst and an ASC catalyst which are communicated in sequence. The combustor is used for introducing fuel and carrying out combustion reaction; the filter is used for filtering upstream particulate matters generated by combustion reaction; the mixing pipe is used for introducing a nitrogen oxide reducing agent and a simulation gas component, and is used for mixing the filtered combustion product, the nitrogen oxide reducing agent and the simulation gas component to form a mixed gas; the SCR catalyst is used for promoting a catalytic reduction reaction of the mixed gas; the ASC catalyst is used for carrying out ammoxidation reaction; and a downstream particle counter is arranged at an outlet of the ASC catalytic converter. By using the PN emission characteristic test system for the nitrogen oxide reducing agent of the diesel engine in the technical scheme, the particulate matter emission level of the nitrogen oxide reducing agent of the diesel engine can be tested.

The invention relates to the technical field of conditioning meat products, and provides a method for controlling and researching frozen storage quality deterioration of conditioned chicken wings by steady-state EGCG (epigallocatechin gallate), which comprises the following steps: step 1, sample treatment: conditioning unfrozen chicken wings; step 2, measuring the color, the unfreezing loss, the ferrimyoglobin, the sulfydryl, the Shore band, the thiobarbituric acid value TBARS and the volatile basic nitrogen TVB-N of the conditioned chicken wings; 3, analyzing a result; changes of color, unfreezing loss, ferrimyoglobin content, sulfydryl, Shore band, thiobarbituric acid value TBARS and volatile basic nitrogen TVB-N in the chicken wing freezing and thawing process are analyzed and conditioned; and 4, performing sensory evaluation according to the sensory evaluation table. According to the method, the control of the steady-state EGCG on the frozen storage quality deterioration of the conditioned chicken wings can be better studied.

The invention provides a method for detecting the contents of collagen and regenerated silk fibroin in a composite material, which comprises the following steps: (1) hydrolyzing the composite material for a certain time, and neutralizing to obtain a solution to be detected; (2) preparing a tyrosine reference solution; and (3) detecting the peak areas of the solution to be detected and the tyrosine reference substance solution by adopting high performance liquid chromatography, and calculating to obtain the content of regenerated silk fibroin in the composite material, and (4) detecting the total nitrogen content of the composite material by using a Kjeldahl method, and calculating to obtain the collagen content in the composite material. According to the method, the high performance liquid chromatography is combined with the Kjeldahl determination method, accurate determination of two components can be realized without derivatization treatment, the operation is simple and convenient, and the detection cost is low; the limit of quantitation of the method reaches 10.35 mu g / mL (S / N is greater than or equal to 16.59), the precision RSD is less than 1%, and the method has high sensitivity and accuracy.

The invention discloses a method for improving the yield of hybrid pennisetum and the soil quality of a planting land, which comprises the following steps: measuring nutritional ingredients in biogas slurry of a pig farm, including organic matters, total nitrogen, total phosphorus and total potassium; biogas slurry and chemical fertilizers with different application gradients are designed to keep the nitrogen level stable; through field trials, the yield of the hybrid pennisetum and the physicochemical properties of soil under different treatments are measured so as to determine the maximum safe absorption amount. According to the method, scientific fertilization of the hybrid pennisetum is realized by accurately measuring nutritional ingredients in the biogas slurry of the pig farm and designing the biogas slurry and the chemical fertilizer with different application gradients, so that the yield of crops is remarkably increased. Meanwhile, the maximum safe absorption amount of the biogas slurry is determined through field trials, and a scientific basis is provided for reasonably utilizing livestock and poultry breeding wastes. According to the method, by optimizing application of the biogas slurry, the physical and chemical properties of soil are improved, the soil fertility is improved, resource utilization of agricultural waste is achieved, and sustainable development of ecological agriculture is promoted.

Provided is an analysis device and an analysis method which, while solving the problem of column plugging, carries out continuous analysis of nitrogen in a sample without use of cadmium that causes environmental pollution. The problem is solved by an analysis method including: a sample introduction step of introducing a sample into a tube; a reduction step of reducing, to ammonium ions, nitrate ions and nitrite ions in the sample being transferred in the tube; and an analysis step of analyzing the ammonium ions in the sample which have been generated in the reduction step. In the reduction step, the nitrate ions and the nitrite ions in the sample are reduced by transferring the sample in a hollow tube in which at least an inner wall surface is made of zinc.

The application provides a cultivated soil biological health condition evaluation method and system based on exploratory factor analysis, relates to the soil biological health condition evaluation technical field, and realizes accurate analysis on the complex interaction relationship between soil microbial functions and environmental factors by constructing a soil biological health evaluation system based on a nitrogen biological regulation coordination network; through multidimensional index fusion and deep mining of a factor model, key biological function factors are effectively identified and quantified, and the scientific evaluation ability of soil ecological functions is improved; combined with causal path analysis, the scheme can reveal the influence of environmental pressure on microbial regulation mechanism, realize intelligent attribution and tracing of abnormal health conditions, based on dynamic fusion and hierarchical determination of function and environment scores, the scheme supports accurate health condition evaluation and layered intervention, enhances the early warning ability and decision-making scientificity of soil management, and significantly improves the guarantee level of agricultural sustainable development.

The application belongs to the technical field of food safety, and particularly relates to a volatile organic compound detection device based on olfactory visualization technology and a detection method thereof. The device comprises a fixed frame structure, a control module is arranged above the fixed frame structure, a detection platform is arranged below the fixed frame structure, a pipette and an image acquisition device and a sensor control device are respectively arranged above both sides of the detection platform, and the control module is connected with the pipette, the image acquisition device and the sensor control device. The control module is used for controlling the pipette, the image acquisition device and the sensor control device to operate in the detection platform area. The application can prepare a color-sensitive sensor printed with a metal porphyrin, obtain volatile gas of an organic compound, and cause a coordination reaction with the volatile gas. Image data before and after the reaction of the volatile gas with the organic compound is detected and analyzed through the image acquisition device, and corresponding chemometrics methods are combined, so that rapid quantitative analysis of the organic gas can be realized.

The present invention provides a Kjeldahl nitrogen determination high-efficiency distillation system, a Kjeldahl nitrogen determination instrument and a distillation method, and belongs to the technical field of Kjeldahl nitrogen determination. The present invention proposes for the first time the strategies and corresponding structures of "steady-state flash" (i.e. Steady-Flash) and "green condensation". The superheated steam for heating the reagent in the digestive tube is two streams, which are heated at the top and bottom of the reagent at the same time. The splash-proof bottle has high temperature and low pressure without blind-end pipelines. The condenser relies on air cooling to dissipate heat, and low temperature and low pressure are achieved through "green technology"; the high-temperature reagent in the digestive tube is lifted by steam, and the boiling point is reduced after decompression, and the "flash evaporation" phenomenon continues to occur. While the reagent is stably and accurately distilled, the reagent distillation speed is accelerated, the distillation time is shortened, and the distillation efficiency is improved.

The present invention discloses a sample injection device for an automatic Kjeldahl nitrogen analyzer, which relates to the field of Kjeldahl nitrogen analyzers and includes a Kjeldahl nitrogen analyzer body, wherein the upper part of the Kjeldahl nitrogen analyzer body has an equipment accommodating chamber, a mixing cylinder is installed at the inner bottom of the equipment accommodating chamber, a stirring assembly is provided in the mixing cylinder, and a liquid discharge pipe is provided at the bottom of the mixing cylinder, a first electromagnetic valve is installed on the liquid discharge pipe, and the bottom end of the liquid discharge pipe extends out of the bottom of the equipment accommodating chamber and extends into the inner top of the butt joint pipe, the butt joint pipe is fixed to the bottom surface of the equipment accommodating chamber, and the bottom end of the butt joint pipe is directly opposite to the top of the glass test tube, and a quantitative injection assembly is also provided at the top of the equipment accommodating chamber. The present invention realizes the purpose of accurately controlling the amount before the reaction through the quantitative injection assembly to ensure the accuracy of the subsequent test results, and this process is automatically carried out, reducing the amount of operation of the experimenter, and has a strong promotion effect.

The invention relates to the technical field of grassland planting, and discloses a saline-alkali soil mixed sowing grassland improved planting method, which comprises the following steps: collecting soil samples of different areas of saline-alkali soil, marking information, detecting indexes such as salinity and pH value, and removing abnormal data to obtain soil basic data; preparing a regulating embedding medium, and preparing a growth zone substrate; then delimiting leguminous and gramineous growth zones according to soil and terrains, filling a matrix, and mixing, sowing and compacting; then erecting an irrigation pipe, alternately irrigating fresh water and salt water, trickle-irrigating corresponding bacterial liquid, and preserving moisture to promote field planting; and finally, setting a mowing rotation rest period, regularly rechecking soil and grassland conditions, and adjusting parameter circulation until an improvement target is achieved. The improvement efficiency of the saline-alkali soil and the sustainability of mixed sowing grassland are greatly improved, and the improvement requirements of areas with different terrains and saline-alkali grades are met.

This invention relates to a method for predicting plant element content based on the interannual variation of element content in jujube tree rings. The method includes: (1) cutting off the main trunk of a jujube tree, cross-dating the annual rings and slicing them, measuring the nitrogen, phosphorus, and potassium content in each year of the trunk's annual rings, determining the correlation coefficients between the nitrogen, phosphorus, and potassium content in each year of the annual rings and the elemental indicators for the predicted year, and screening based on the obtained correlation coefficients to obtain screening indicators; (2) using the obtained screening indicators to establish multiple linear regression models for nitrogen, phosphorus, and potassium elements respectively, obtaining the optimal multiple linear regression model, and predicting the interannual variation of nitrogen, phosphorus, and potassium content in the annual rings. This invention's method for predicting plant element content based on the interannual variation of element content in jujube tree rings constructs a multiple linear regression model to predict the interannual variation of nitrogen, phosphorus, and potassium content in the annual rings, enabling balanced fertilization in jujube orchards.

The present invention provides a continuous analysis device and an analysis method for nitrogen in a sample that do not use cadmium, which is a cause of environmental pollution, and solves the problem of column clogging. This is solved by an analysis method including a sample introduction step of introducing a sample into a pipeline, a reduction step of reducing nitrate ions and nitrite ions in the sample transferred in the pipeline to ammonium ions, and an analysis step of analyzing ammonium ions in the sample generated in the reduction step. In the reduction step, the sample is transferred through a hollow tube made of zinc at least on the inner wall surface to reduce nitrate ions and nitrite ions in the sample.

The present invention discloses a novel automatic Kjeldahl nitrogen analyzer, and relates to the technical field of Kjeldahl nitrogen analyzers, including a fully automatic Kjeldahl nitrogen analyzer body, wherein the Kjeldahl nitrogen analyzer body is provided with a test tube placement area for placing test tubes, a lifting plate movable in a vertical direction is arranged at the bottom of the test tube placement area, a test tube holder is rotatably connected to the upper surface of the lifting plate, a plurality of outer tube grooves for placing test tubes are provided in the circumference of the test tube holder, and a positioning mechanism for limiting the circumference of the bottom of the test tube is arranged in each outer tube groove. The present invention can load different kinds of test substances into test tubes at one time through a turntable test tube holder, and then move them to the middle middle tube barrel in turn for titration detection, thereby eliminating the step of placing the test tubes one by one under the test tube placement area for titration, greatly improving the detection efficiency, and having a significant use effect.

The application discloses a method for determining the purity of gamma-aminopropyl triethoxysilane by using an automatic nitrogen determination instrument, and the steps comprise the following steps: mixing gamma-aminopropyl triethoxysilane standard and gamma-chloropropyl triethoxysilane standard according to different mass ratios to obtain a series of standard samples; performing digestion treatment on the standard samples, then detecting the nitrogen content by using the automatic nitrogen determination instrument to obtain a linear regression equation of the gamma-aminopropyl triethoxysilane content and the nitrogen content; performing digestion treatment on a gamma-aminopropyl triethoxysilane sample to be measured, then detecting the nitrogen content, and bringing the nitrogen content into the linear regression equation to obtain the purity of the gamma-aminopropyl triethoxysilane. The application firstly proposes to detect the purity of KH550 by using the automatic nitrogen determination instrument, the method is simple and rapid, reduces human errors, reduces the working strength, has high accuracy of the determination result, is easy to popularize and apply, and has substantial significance for determining the purity of KH550.

A multi-performance testing device for an SDPF system includes a pure water storage tank, an evaporator, a regulating valve, a pressure gas cylinder, a gas cylinder opening control unit, an air pump, a mixed air flow screen, a particle tank, a particle mixer, a flow meter, a gas heater, a mixing chamber, a silicone tube, a particulate matter sensor, a urea tank, a urea pump, a urea nozzle, a SDPF catalyst sample, an ASC catalyst sample, a temperature sensor, a heat-insulating heating tube, a pressure sensor, a continuous weighing platform, a gas analyzer, and a computer. The device provides quantitative feeding, gas component adjustment, temperature control, particulate matter / gas mixing, continuous SDPF system weighing, and gas analysis. It can test the SDPF's DeNOx performance, ammonia storage performance, particulate matter capture capacity, carbon loading-pressure differential relationship, and ammonia storage-conversion efficiency relationship under different temperatures, exhaust mass flow rates, gas component volume concentrations, and particulate matter mass concentrations.

The invention discloses a novel method and an instrument for measuring ammonia nitrogen in water. The method comprises the following steps: injecting 5ml of a to-be-measured sample or blank secondary water and a small amount of sodium hydroxide solution into a small distillation flask, distilling off water and generated ammonia gas, cooling, feeding into a 5ml volumetric flask filled with 1ml of electrolyte, taking down the volumetric flask when the solution just reaches a 5ml scale line, uniformly shaking, accurately measuring a certain amount of solution each time, the sample is injected into a micro-coulometric titration cell with a photoelectric indication signal in normal operation, the ammonia nitrogen content in the sample is automatically measured, and after a blank value is deducted, the instrument automatically displays the ammonia nitrogen content in the sample. Compared with a classical distillation-neutralization titration method, the method disclosed by the invention has the advantages of simple distillation device, less required sample amount, low energy consumption and no need of calibration solution. The method is especially suitable for measuring ammonia nitrogen in domestic sewage and industrial wastewater treatment plants.

The application relates to the technical field of paint production, and particularly discloses a method for detecting the polymerization reaction proportion of two-component polyurethane paint. The method comprises the following steps: S1, crushing and sieving a polyurethane coating to be detected to obtain coating powder; S2, taking the A component, the B component and the coating powder of the two-component polyurethane paint as samples to be detected, digesting each sample to be detected, then measuring the nitrogen content of the digestion product, and calculating the polymerization reaction proportion of the polyurethane coating to be detected according to a formula. The application creatively detects the nitrogen content of the coating and the two-component paint to infer the polymerization reaction proportion of the two components, and then assesses whether the control of the mixing proportion of the two-component polyurethane paint is accurate, so that spraying abnormalities can be found in time, and the stability of the polyurethane paint quality can be ensured.

The invention discloses a multi-element type soil nutrient prediction method coupling multi-source covariables and an in-situ spectrum. The method comprises the following steps: step 1, soil in-situ hyperspectral measurement and data acquisition; 2, collecting and preparing a soil sample; step 3, acquiring covariable data; step 4, acquiring soil nutrient data; step 5, in-situ spectrum data pretreatment: carrying out pretreatment operation on the soil in-situ spectrum; step 6, detecting and eliminating abnormal values of the spectral data; step 7, feature dimension reduction and screening; 8, constructing a multi-target regression prediction model of the soil nutrient content; step 9, model prediction performance evaluation and comparison; and step 10, quantifying the contribution of the multi-source covariable in model prediction. The method provided by the invention overcomes the defects of large prediction deviation and weak generalization ability caused by multi-element soil and multi-target nutrient modeling in the prior art, and can realize efficient, lossless and accurate prediction of the total nutrient content and the effective nutrient content of the multi-element soil under the provincial scale.

The present invention provides a method for treating nitrate nitrogen in biological tissues 15 The method for determining nitrogen abundance belongs to the technical field of element quantitative detection. The determination method provided by the present invention overcomes the problem of low accuracy or even inability to detect in the prior art determination method. The determination method of the present invention can avoid the adverse effects caused by concentrated sulfuric acid reagents and can successfully detect the nitrate nitrogen in biological tissues. 15 N abundance can be accurately detected even for arbuscular mycorrhizae that have high detection requirements.

Provided is an analysis device and an analysis method which, while solving the problem of column plugging, carries out continuous analysis of nitrogen in a sample without use of cadmium that causes environmental pollution. The problem is solved by an analysis method including: a sample introduction step of introducing a sample into a tube; a reduction step of reducing, to ammonium ions, nitrate ions and nitrite ions in the sample being transferred in the tube; and an analysis step of analyzing the ammonium ions in the sample which have been generated in the reduction step. In the reduction step, the nitrate ions and the nitrite ions in the sample are reduced by transferring the sample in a hollow tube in which at least an inner wall surface is made of zinc.

The present invention relates to a method for quantitatively determining the binding force between rice starch granules and proteins and their components in the field of agricultural product analysis technology. It sequentially measures the binding force between albumin, globulin, glutelin, and prolamin and starch granules, and finally calculates the average value to obtain the binding force between starch granules and total protein, and uses this value to evaluate or improve the taste and texture of rice foods. The larger the C value, the greater the binding force between starch granules and proteins, and the better the viscosity and elasticity of starch granules. This method is not limited to measuring the binding force between starch granules and total protein in rice, but can also be used for measuring the binding force between starch granules and total protein in other grains, such as wheat, corn, millet, etc.

The invention discloses a seedling management method and system for high-yield direct seeding of annual Angelica sinensis, and the invention relates to the technical field of Chinese medicine planting. The method comprises: dividing a planned direct seeding plot into a plurality of sub-areas of equal area, and randomly selecting soil of different depths in each sub-area for sampling to obtain soil nutrient parameters; based on these parameters, calculating the nutrient content of each sub-area, and setting a nutrient content threshold, and improving the soil in areas below the threshold; collecting soil environmental parameters and Angelica sinensis seed diameter data, calculating the sowing depth, determining the plant planting row spacing and column spacing according to the effective illumination area in each sub-area, sowing in the improved soil, establishing a pest and disease classification model, judging the growth state of Angelica sinensis according to the model output, issuing corresponding processing instructions, improving the photosynthetic efficiency and growth balance of the plant, optimizing the utilization efficiency of land and resources, and reducing the impact of pests and diseases on yield and quality.

The invention provides a passive smart tag for meat food detection and a meat food freshness detection method. The passive smart tag for meat food detection comprises a transducer, a sensitive element, an analog front end, a microprocessor, an NFC chip and an antenna, the sensitive element is used for adsorbing the biogenic amine volatilized during meat decay, and the transducer converts the concentration of the biogenic amine into an electrical impedance signal; the analog front end collects an electrical impedance signal output by the sensitive element and converts the electrical impedance signal into a digital signal; the microprocessor obtains the nitrogen content in the meat food according to the digital signal and the mapping relation between the total nitrogen content of the volatile basic group of the meat and the impedance variable quantity; the NFC chip sends the nitrogen content in the meat food to a client side through the antenna, the freshness degree of the meat food under various storage conditions and various transportation conditions is detected, the freshness index is quantified through the nitrogen content, and technical support is provided for detecting whether food materials and dishes are fresh or not.

The present invention provides a reliable Kjeldahl nitrogen determination steam generation system, a Kjeldahl nitrogen determination instrument and a method, comprising: a steam generator, an output pipeline of the steam generator is connected with a temperature sensor, an input port of the steam generator is connected with an output port of a pump group through a pipeline, and the input port of the pump group is used to communicate with a water source; the pump group at least comprises a first branch, a second branch and a third branch connected in parallel through the pipeline, and the first branch, the second branch and the third branch are selected according to the value of the temperature sensor, so that the value of the temperature sensor is stable within a set temperature range; the present invention realizes the reliable and stable operation of the steam generation system by connecting a plurality of pumps in parallel and working intermittently, effectively avoids the influence on the nitrogen determination experiment, and improves the test accuracy.

The invention relates to the technical field of sugar-free cake premixed flour processing, and particularly discloses a processing technology of sugar-free cake premixed flour, which comprises the following steps: raw material screening and pretreatment: selecting raw materials which meet specific quality standards and are not added with cane sugar, including xylitol, erythritol, maltitol and other sugar substitutes, the preparation method comprises the following steps: pre-treating all the raw materials with flour, mannan-oligosaccharide, chitosan oligosaccharide, a leavening agent, edible salt and an emulsifying agent to ensure that the granularity of the raw materials meets the subsequent processing requirements; and precisely proportioning: weighing 30 parts of xylitol, 30 parts of erythritol, 40 parts of maltitol, 0.4 part of mannose oligomer, 0.3 part of chitosan oligosaccharide, 350 parts of flour, 15 parts of a leavening agent, 3 parts of edible salt and 8 parts of an emulsifying agent in parts by weight. According to the processing technology of the additive-free sugar cake premixed flour, vibration screening is combined with screens with different mesh numbers, impurities of flour and sugar substitute raw materials are accurately removed, ferromagnetic impurities are intercepted through magnetic separation, the product taste is improved, and equipment loss is reduced.

The invention discloses a deep soil nitrogen content monitoring method, a server and a storage medium, and belongs to the field of soil component monitoring, and the method comprises the following steps: obtaining remote sensing image data of surface soil of a soil sampling point, and collecting a soil sample of the corresponding soil sampling point; performing preprocessing, spectral transformation and spectral feature extraction on the remote sensing image data, and constructing a multi-dimensional feature space; analyzing the corresponding soil sample to obtain a change rule of surface nitrogen and deep nitrogen, and obtaining a surface-deep nitrogen relation model; screening a characteristic wave band combination of which the correlation with the surface nitrogen content exceeds a threshold value from the multi-dimensional characteristic space, and establishing a surface nitrogen content inversion model; in the actual use process, after remote sensing image data are collected, the nitrogen content of deep soil is monitored through the surface layer nitrogen content inversion model and the surface layer-deep layer nitrogen element relation model. The method avoids the problems of high cost and low timeliness of traditional sampling analysis.