122 results about "Mid infrared spectroscopy" patented technology

A method for identifying and quantifying one or more analytes included in a sample comprising a background solvent is disclosed. The present invention locates a sample fluid at a sample region by virtue of a sample holder that comprises work-hardened silver halide. The sample fluid at the sample region is then spectrally characterized via a mid-infrared spectrometer.

The invention belongs to the field of milk product analysis and particularly relates to a spectral fingerprint identification method for milk, mare milk, camel milk, goat milk and buffalo milk. The invention relates to the intermediate infrared spectroscopy. The method comprises the following steps: 1) taking fresh milk, mare milk, camel milk, goat milk and buffalo milk samples; 2) scanning the samples in a mid-red spectral range to obtain mid-infrared spectral data; 3) preprocessing original mid-infrared spectrum to remove abnormal values; 4) dividing the preprocessed data set into a trainingset and a test set according to a stratified sampling principle; 5) performing dimension reduction processing on the training set to improve the model training speed; 6) establishing a model for distinguishing milk, mare milk, camel milk, goat milk and buffalo milk through 10-fold cross validation by using algorithms such as nearest neighbors on the training set, and evaluating and screening themodel by using the use accuracy, the balance precision and the Kappa coefficient; and 7) estimating the generalization performance of the optimal model.

The present invention relates to a method for the determination of the total acid number and naphthenic acid number of petroleum, petroleum cuts and petroleum emulsions of water-in-oil type by mid-infrared spectroscopy utilising correlation between data gathered by means of absorption spectrums obtained with a Fourier-transform infrared spectrophotometer operating in the mid-infrared band equipped with an attenuated total reflectance (ATR) accessory, and acidity results obtained through reference methods utilising a multivariate regression model.

The invention discloses a method for quantitative detection of tobacco lignin by adopting mid-infrared spectroscopy. The method comprises the steps of finding out a characteristic absorption peak from the measured infrared spectrogram, and measuring the area of the peak; importing the original data of the measured infrared spectrogram into PeakFi tv 4.12 software, and carrying out fitting peak separation on the 1508 cm<-1> characteristic peak. According to the method, the fitting correlation coefficient of the standard curve of a lignin reference object reaches 0.9914, so that the requirement of accurate quantization can be reached, the detection result is accurate, and the repeatability is good. The method overcomes the defect that the existing chemical detection method consumes a great deal of time and reagent, and solves the problem that in the existing quantitative analysis method, the lignin in tobaccos is difficult to separate and purify; an in-situ analysis method of the tobacco lignin is established scientifically; the method can be used for conveniently, rapidly and accurately measuring the content of the lignin of multiple tobacco stem powders.

A method of determining a physical property of a composite material includes providing a series of composite materials / surfacing films, which are subjected to increasing thermal experience to create a set of thermal effect standards, collecting mid-IR spectra on those standards, performing data pre-processing and then multivariate calibration on the spectra of the composite materials / surfacing films, and using that calibration to predict the thermal effect for samples in question.

This disclosure relates to hollow fibre waveguide spectroscopic gas cells built using connectors and the method for making them. The connectors are used to construct gas cell end pieces which allow gas and light to enter the hollow fibre waveguide simultaneously thus creating a gas cell. The connectors comprise a window which intersects or is in close proximity to a junction of bores within the connector, the bores transmitting gas through the connector to or from the hollow fibre waveguide. Connectors may also be used to connect two sections of fibre together in order to produce longer gas cells which enhance the signal-to-noise ratio of spectroscopic measurements. The window, which is at least partially transparent at the wavelength of the light used for spectroscopic purposes, is affixed so as to maintain a gas tight seal for the gas cell. These gas cells provide a combination of long path length and low volume and are well suited to mid-infrared spectroscopic applications which require a fast response time or low flow rate.

The invention discloses a radiation refrigeration coating with a gradient structure and a preparation method and application thereof, and belongs to the field of novel materials. The invention provides the radiation refrigeration coating with a gradient structure. The coating comprises a polymer adhesive and inorganic powder which are blended, wherein the emissivity of the polymer adhesive in a middle-infrared band is higher than 0.85, the reflectivity of the inorganic powder in a solar spectrum band is higher than 0.85, and the content of the polymer adhesive is gradually reduced and the content of the inorganic powder is gradually increased in a direction far away from a radiation surface. In this way, it can be guaranteed that a large number of the polymer adhesive is located on the upper portion and the inorganic powder is located on the lower portion in the coating, and due to the fact that the polymer adhesive is used for emitting mid-infrared spectra and the inorganic powder ismainly used for reflecting solar spectra, a good refrigerating effect can be guaranteed. The polymer adhesive and the inorganic powder form the integrated coating, so that the problems of peeling, delaminating and the like caused by lamination of two layers of materials can be prevented, and the effects of balanced transition in structure and structural stability are achieved.

The invention belongs to the field of milk product analysis, and particularly relates to a methodfor quickly identifying milk and mare milk, which is relates to intermediate infrared spectroscopy. The method comprises the following steps: 1) taking fresh mare milk and milk samples; 2) scanning the samples in anintermediate infrared spectral range to obtain intermediate infrared spectral data; 3) preprocessing the original intermediate infrared spectrum to remove abnormal values; 4) dividing the preprocessed data set into a training set and a test set according to a stratified sampling principle; 5) performing dimension reduction processing on the training set to improve the model training speed; 6) on the training set, establishing a model for distinguishing mare's milk from milk through 10-fold cross validation by using algorithms such as a nearest neighbor algorithm, and evaluating and screening the model by using accuracy, specificity, sensitivity and AUC; and 7) estimating the generalization performance of the optimal model.

The invention belongs to the field of milk product analysis, and particularly relates to a batch identification model and method for camel milk and mare milk. The invention relates to mid-infrared spectroscopy analysis. The method comprises the following steps: 1) taking fresh mare milk and camel milk samples; 2) scanning the samples in a mid-red spectral range to obtain mid-infrared spectral data; 3) preprocessing the original mid-infrared spectrum to remove abnormal values; 4) dividing the preprocessed data set into a training set and a test set according to a stratified sampling principle; 5) performing dimension reduction processing on the training set to improve the model training speed; 6) on the training set, establishing a model for distinguishing mare milk from camel milk through 10-fold cross validation by using algorithms such as nearest neighbors, and evaluating and screening the model by using accuracy, specificity, sensitivity and AUC; and 7) estimating the generalization performance of the optimal model.

Methods and systems for performing high throughput spectroscopic measurements of semiconductor structures at mid-infrared wavelengths are presented herein. A Fourier Transform Infrared (FTIR) spectrometer includes one or more measurement channels spanning a wavelength range between 2.5 micrometers and 12 micrometers. The FTIR spectrometer measures a target at multiple different angles of incidence, azimuth angles, different wavelength ranges, different polarization states, or any combination thereof. In some embodiments, illumination light is provided by a laser sustained plasma (LSP) light source to achieve high brightness and small illumination spot size. In some embodiments, FTIR measurements are performed off-axis from the direction normal to the surface of the wafer. In some embodiments, a Stirling cooler extracts heat from the detector of an FTIR spectrometer. In another aspect, measurements performed by one or more spectrometer measurement channels are combined with measurements performed by a mid-infrared FTIR spectrometer channel to characterize high aspect ratio structures.

The invention relates to a method for carrying out surface-enhanced infrared absorption spectroscopy (SEIRAS) detection by adopting nanoscale aluminium-doped zinc oxide (AZO) as a substrate, belonging to the technical fields of nano materials and detection. The invention in particular relates to a new method for carrying out the SEIRAS detection on probe molecules within a mid-infrared spectroscopy fingerprint region range of 1300-600 cm<-1> by adopting the nanoscale AZO as the substrate. The method comprises the three steps of synthesizing an aluminium-doped AZO nano-material, carrying out surface modification on the probe molecules, and carrying out the SEIRAS detection on the probe molecules by taking the AZO nano-material as the novel SEIRAS substrate. By using the enhanced substrate, SEIRAS signals adsorbed to the surface of the AZO nano-material are detected to be significantly enhanced compared with infrared signals of the probe molecule bodies, and the enhancement factor can reach 103. After the method is adopted, more information about the structures and interaction of a material surface and probe molecules can be obtained, and theoretical and experimental basis for studying the mechanism of an SEIRAS effect is provided; furthermore, a foundation is laid for the developing the SEIRAS effect as a universal characterization tool for the material surfaces.

The invention relates to a wheat grain resistant starch content rapid measurement method and belongs to the technical field of wheat grain resistant starch content prediction. The wheat grain resistant starch content rapid measurement method achieves a purpose of rapidly measuring the wheat grain resistant starch content by establishing a medium-infrared spectroscopy model related to the wheat grain resistant starch content. Compared with a chemical measurement method, the method is fast, efficient and environmentally friendly, and meets the needs of people.

The invention discloses a method for rapidly determining oil contents of agricultural products by using a mid-infrared spectrometer based on horizontal attenuated total reflection (ATR), and relates to the field of rapid detection of the oil contents of the agricultural (food) products. A dry agricultural (food) product is ground, dissolved by using a certain amount of Alpha-bromonaphthalene and filtered; a filtrate is placed on a horizontal ATR crystal; an ATR infrared spectrum of the filtrate is collected; and the oil content of the filtrate is pre-determined by using a well-established model. The method disclosed by the invention has the advantages that the oil contents of the agricultural (food) products can be analyzed rapidly, simply, conveniently and quantitatively only by simply preprocessing samples, the detection linear range is wide and an accurate and reliable result is obtained.

An infrared spectrometer for operation in the mid-infrared spectral range is presented, where the spectrometer includes a Bragg-mirror-based spectral filter that is operative for providing an interrogation signal whose spectral content is dispersed along a first direction at a filter aperture. The filter aperture is imaged through a sample by a thermal-imaging camera to create a focused image that is based on the interrogation signal and the absorption characteristics of the sample. As a result, embodiments in accordance with the present disclosure can be smaller, less complex, and less expensive than infrared spectrometers known in the prior art.

The invention belongs to the field of dairy product analysis, and particularly relates to a rapid identification method for four kinds of high-temperature sterilized commercial milk. The four kinds of high-temperature sterilized commercial milk are pure milk, high-end milk, organic milk and A2-beta casein milk. The method comprises the steps of 1) collecting samples of four kinds of high-temperature sterilized milk; 2) scanning the samples in the mid-infrared spectrum range to obtain mid-infrared spectrum data; 3) preprocessing the original mid-infrared spectrum to remove abnormal values; 4) dividing the preprocessed data set into a training set and a test set according to a stratified sampling principle; 5) screening spectral bands for modeling; 6) combining different spectrum preprocessing methods and modeling algorithms, establishing an identification model, evaluating the model by using accuracy and a Kappa coefficient, and screening out an optimal preprocessing method and modeling algorithm combination to obtain an optimal model; and 7) verifying the model, and evaluating the generalization ability of the model.

A method of predicting content of hydrogen sulfide in desulfuration amine liquid through mid-infrared spectroscopy includes the following steps: 1) collecting a series of desulfuration amine liquid samples in different concentrations, and detecting the content of hydrogen sulfide of the samples through a standard method; 2) measuring the mid-infrared spectroscopy of the desulfuration amine liquid samples collected in the step 1), setting the spectroscopy within the range of 950-1250 / cm as a characteristic spectrum zone, correlating the absorbance of the characteristic spectrum zone to the content, which is detected through the standard method, of hydrogen sulfide of the samples, and establishing a calibration model through multivariate regression analysis; and 3) measuring the mid-infrared spectroscopy of the samples, and substituting the absorbance within the range of 950-1250 / cm into the calibration model to obtain the content of hydrogen sulfide in the samples. The method is high in analytic speed, is accurate in measurement and is good in repeatability.

The invention discloses a method for rapidly predicting adulterated dendrobium huoshanense of dendrobium Henan. The method comprises the following steps: (1) preparing an adulterated dendrobium huoshanense powder sample; (2) collecting an infrared spectrum; (3) performing spectrum pretreatment; (4) screening spectral characteristic wavelengths; and (5) performing adulteration amount prediction. According to the invention, by adopting a method for collecting the same sample for multiple times and preprocessing the spectrum, the manual sampling error and the influence of the scanning times, the resolution, the temperature and the optical path on the mid-infrared spectrogram can be effectively reduced; characteristic wavelength variable screening is carried out through three different wavelength selection methods of a moving window partial least square method, a Monte Carlo uninformative variable elimination method and an interval random frog method, and useless variables and interference information in an intermediate infrared spectrogram can be effectively compressed. Meanwhile, a spectrum pretreatment method and a wavelength screening method which are most suitable for the prediction model are obtained, an accurate and reliable adulteration prediction model is established, and the adulteration amount in an adulterated dendrobium huoshanense sample is rapidly measured.

The invention discloses an efficient forehead temperature estimation method based on wide-spectrum human forehead imaging and distance sensing, and provides the scheme for solving a problem of complexcalculation of forehead temperature measurement in the prior art. The method comprises a neural network training step, a step of calculating an optimal value of a coefficient in a temperature measurement model, a step of performing forehead region image interception and energy value calculation by using a neural network, a step of obtaining a distance of an object human body, and a step of calculating the temperature of the object human body by using the temperature measurement model. The method is suitable for a whole mid-infrared spectrum range, efficient in calculation and low in hardwarecost. Compared with other areas of a human face, the mid-infrared imaging of the forehead region of the human body not only contains stable temperature information, but also can effectively avoid thermal induction interference caused by shielding of glasses and masks possibly worn on the human face. The method can be used for forehead temperature estimation of multiple persons, which means that when multiple persons exist in a scene, after infrared imaging and imaging distances in face regions of different persons are obtained, a forehead temperature value of each person can be rapidly calculated.

The invention provides a method for quick detection of the stable carbon isotope ratio of soil by means of mid-infrared spectroscopy.The method comprises the steps of 1, measuring the stable carbon isotope ratios of multiple calibration soil samples; 2, acquiring the diffuse reflection spectrogram of middle-infrared bands of the calibration soil samples to obtain an original spectrogram; 3, conducting smooth pretreatment on the original spectrogram to obtain a treated spectrogram; 4, establishing a model about the quantitative relation between the treated spectrogram of the calibration soil samples and the stable carbon isotope ratios by means of a support vector machine; 5, acquiring the diffuse reflection spectrogram of the middle-infrared band of a soil sample to be measured, and calculating the stable carbon isotope ratio of the soil sample to be measured according to the quantitative relation model.By the adoption of the method, the delta 13 C value of soil can be measured quickly, accurately and easily at low cost.

The invention discloses a solid waste plastic material identification method based on a double-layer classification algorithm, and the method comprises the steps: collecting infrared spectrum data in a sample through a Fourier infrared spectrometer, and carrying out the preprocessing operation of data correction, smooth noise reduction, water peak elimination and the like on the sample data; then, adopting a spectral angle mapping method and a standard sample to perform primary classification on a to-be-detected sample, selecting a wave crest detection algorithm or a support vector machine method according to a classification result to perform secondary classification on the sample, and finally, obtaining the final classification condition of the sample by combining the two classification results. The method has the advantages of no damage, rapidness, high detection precision, no secondary pollution, accurate classification and the like, and can be applied to recovery and utilization of waste plastics in specific life.

The invention belongs to the technical field of dairy product analysis and particularly relates to a rapid identification model for yak milk and milk doped with the yak milk. The invention relates to the field of mid-infrared spectrum analysis. The method comprises the following steps of 1) taking fresh yak milk and a yak milk sample doped with milk; 2) scanning the sample in the medium infrared spectrum range to obtain medium infrared spectrum data; 3) preprocessing the original mid-infrared spectrum to remove abnormal values; 4) dividing the preprocessed data set into a training set and a test set according to a stratified sampling principle; 5) screening a spectral band for modeling; 6) combining different spectrum preprocessing methods and modeling algorithms, establishing an identification model, evaluating the model by using accuracy and a kappa coefficient, and screening out the combination of the preprocessing method and the modeling algorithm with the optimal effect to obtain an optimal model; and 7) verifying the model, and evaluating the generalization ability of the model.

The invention relates to the field of foodstuff safety, and discloses a method for detecting lime-like substances in flour. The invention comprises the steps of: collecting microscopic mid-infrared images of flour samples requiring detecting; carrying out image analysis upon the microscopic mid-infrared images of the flour samples according to mid-infrared spectral features of lime-like substances and pure flour; calculating derivative spectrums of the lime-like substances and the pure flour according to the mid-infrared spectrums; and carrying out spectrum enhanced image analysis upon the microscopic mid-infrared images of the flour samples according to the derivative spectral features. According to the method for detecting lime-like substances in flour, complicated pretreatment is not required during a detection process; the detection steps are simple and quick; and detection results are accurate and reliable. Also, a target sample dimension of microscopic mid-infrared imaging reaches a micrometer grade, which is similar to a dimension of lime-like substance particles. Therefore, relative to a small lime-like additive amount, the method contributes to a lime-like substance enriching effect within a dimensional scope, such that the additive is easy to be detected.

The invention discloses a method for quantitative analysis of sucralose content through combination of a mid-infrared spectroscopy and a vector angle. The method comprises preparing KBr tablets of a sucralose reference substance, a sucralose-6-ethyl ester reference substance, a two-component mixed sample and a deacylated sample, acquiring infrared spectrum data, acquiring mid-infrared transmittedspectrums of the samples obtained by the step 1 under conditions of 450-4000cm<-1>, resolution 4cm<-1> and data interval of 1cm<-1> and carrying out data processing. The method can quickly and accurately determine the product content of the sucralose synthesis process. The method is free of sample pretreatment, is simple, is free of big data modeling and has the characteristics of independent of spectral response, low detection limit and wide application range.

The invention discloses a sensor system based on a silicon-based mid-infrared sub-wavelength grating waveguide structure, which comprises a laser source, a prism coupling, a gas flow cell, a silicon-based mid-infrared sub-wavelength grating waveguide, a detector, and a computer. The basic principle is that interaction between light generated by the laser source and the gas affects the refractive index distribution of the waveguide mode in the sensor, the variation of a resonance peak in the output spectrum of the sensor is further affected, and based on the variation of the resonance peak, gastype and concentration detection is realized. According to the silicon-based sub-wavelength grating waveguide, top Si of a silicon-on-insulator material is etched to form a sub-wavelength grating (SWG) waveguide, holes are opened at two sides of the waveguide, the insulating layer SiO2 middle part is hollowed out, and a suspension waveguide structure with air as a lower cladding is formed. The gas sensor disclosed in the invention does not require fluorescent labeling, has high sensitivity and can effectively monitor gases such as CO2 and CH4 which have a spectral response in the mid-infraredspectral region.

The invention belongs to the field of dairy cow performance determination and milk quality detection, and discloses an intermediate infrared rapid batch detection method for alpha s1-casein in milk. According to the intermediate infrared rapid batch detection method, on the basis of data obtained by an infrared spectrometer in original Fourier transform, wave bands with much noise and less effective information are removed, manual dimension reduction is carried out, and the intermediate infrared rapid batch detection method for the alpha s1-casein in the milk is finally obtained by preprocessing spectral data through using an SG convolution first-order derivative, extracting intermediate infrared spectral characteristic variables through a competitive adaptive reweighting method, and constructing a regression model by using training set data through a support vector machine regression algorithm. The intermediate infrared rapid batch detection method has the advantages of high identification speed, high precision, low cost, simplicity in operation, batch detection, high practicability and the like, and is suitable for large-scale popularization.

The invention belongs to the technical field of dairy product analysis, and particularly relates to a spectrum identification method for high-temperature sterilized milk, pasteurized milk and pasteurized milk doped with the high-temperature sterilized milk. The method comprises the steps of 1) taking pasteurized milk and high-temperature sterilized milk, and simulating different adding proportions of the pasteurized milk to prepare samples; 2) scanning the samples in a medium infrared spectrum range to obtain medium infrared spectrum data; 3) preprocessing the original mid-infrared spectrum, and removing abnormal values; 4) dividing the preprocessed data set into a training set and a test set according to stratified sampling; 5) screening a modeling spectral band; 6) detecting the sample identification model on the training set through 10-fold cross validation by using a nearest neighbor algorithm and the like, and evaluating and screening the model by using accuracy and kappa coefficients; and 7) verifying the optimal model. According to the method, less wave points are used for modeling, the operation cost is reduced, and the identification rate and accuracy are improved.

The invention discloses a Xinjiang walnut origin traceability researching method. By collecting walnut in Hetian region, Kashgar region and Akesu region of Xinjiang as research objects, a plurality of technologies of near infrared spectroscopy analysis, mid-infrared spectroscopy analysis and element determination analysis are used, a PLSDA method and a variance analysis are combined for distinguishing the walnuts from different producing areas, the result shows that the near infrared distinguishing effect is good, the distinguishing accuracy of a modeling set and a prediction set in the Kashgar region and Akesu region is 100%, the distinguishing accuracy of the modeling set and the prediction set in the Hetian region can reach as high as 99%; the mid-infrared distinguishing accuracy is high, the kind distinguishing accuracy of Xinfeng, Xin2, Zha343 can reach as high as 100%; the content of elements of same kind of walnut has obvious difference among the regions, and Ca and Na elements of the types of Xin2 and Wen185 have obvious difference. The near infrared and mid-infrared analysis and elemental analysis used for traceability of the walnut producing area have good distinguishing effect.