17results about "Nitrogen determination" patented technology

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 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 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 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 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 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 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.

The invention discloses a method for determining the nitrogen index of protein in milk powder and application, and the method comprises the following steps: taking a milk sample, and dissolving in water to obtain an emulsion; adjusting the pH value of the emulsion to precipitate casein and denatured whey protein, and filtering to obtain a filtrate A; determining the nitrogen content in the filtrate A; mixing the filtrate A with a trichloroacetic acid solution to precipitate undenatured whey protein, and filtering to obtain filtrate B; determining the nitrogen content in the filtrate B; the difference value between the nitrogen content in the filtrate A and the nitrogen content in the filtrate B is the nitrogen content of the undenatured whey protein in the milk powder. The determination method disclosed by the invention has the characteristics of high universality, precision, accuracy, operability and the like, and provides a technical basis for determining the denaturation degree of the whey protein in the milk powder.

The invention relates to the technical field, in particular to an amino nitrogen determination automatic calibration system and application thereof. Comprising a titration cell with an opening in the upper end, a six-way switching valve, two peristaltic pumps, a pH electrode and a plurality of reagent liquid bottles. The peristaltic pump with lower cost is adopted for quantitative liquid adding, the stability of a measurement result is kept through pH electrode calibration and peristaltic pump flow calibration, and meanwhile, the cost is reduced. According to the automatic determination method for amino nitrogen provided by the embodiment of the invention, the determination process is accurately operated according to a set program, reagent adding, sodium hydroxide titration, titration cell liquid emptying and cleaning are automatically carried out, and an operator only needs to add a sample into a titration cell by using a microsyringe. The system is simple in structure, accurate in result, convenient to operate and low in cost.

The invention relates to a self-adaptive nonlinear Kjeldahl azotometer titration control method, which belongs to the technical field of chemical analysis instruments, and realizes accurate control of synchronous and efficient titration in a distillation process by dynamically calculating a titration rate by utilizing baseline adjustment and nonlinear control based on calculation of a color ratio and a relative ratio. And by introducing an acceleration and brake control mechanism, the titration efficiency is improved, and the robustness of the titration process is enhanced. In addition, by introducing an abnormal state monitoring mechanism, the operation state of the system is monitored in real time, and the stability of the equipment under the abnormal working condition is effectively guaranteed. The Kjeldahl apparatus titration control method disclosed by the invention is suitable for the fields of food, agriculture, environmental science and the like needing to accurately measure the nitrogen content, and has the characteristics of high precision, high efficiency, high stability, timeliness and automation.

Provided is the use of a TaMADS1-D1 gene in the regulation of wheat quality. TaMADS1-D1 can regulate the grain protein content and wet gluten content of wheat. Overexpression of the TaMADS1-D1 gene in wheat can significantly increase the grain protein content and wet gluten content of wheat.