217 results about "Absorption spectroscopy" patented technology

The methods described herein provide improvements in composite infrared absorption imaging. The scanning approach described herein reduces erroneous measurements caused by thermal drift and optical interference that occurs between light scattering from the top surface of the sample and light scattering from the underlying substrate. Embodiments described herein relate to imaging and spectroscopy, and more particularly, to improvements in photo-thermal imaging and spectroscopy systems, and techniques for obtaining spectral information characterizing optical properties and / or materials or chemical compositions of a sample, such as information related to infrared (IR) absorption spectroscopy.

The invention discloses a distinguishing table type X-ray spectrometer and an X-ray absorption spectrum testing method, and relates to the technical field of spectral measurement. The high-resolution table type X-ray spectrometer comprises a sample signal source which is located in a Dowland circle and is used for generating X-rays; the exponential crystal is a bent crystal, the surface shape of the exponential crystal is defined by an exponential equation, so that different points on the curved surface of the crystal have different curvature radiuses and correspond to Rowland circles with different radiuses, each point on the exponential crystal is tangent to the corresponding Rowland circle, and the exponential crystal is used for performing monochromatization and focusing on the X-ray incident from the sample signal source; and the detector is positioned on a surface formed by the corresponding imaging points on each Rowland circle, and is used for receiving the X-rays which are monochromatized and focused by the index crystal and outputting corresponding light intensity signals. Therefore, through the cooperation of the index crystal and the multi-Rowland circle structure, the X-ray absorption spectrum test with high light receiving efficiency, high spectral resolution and wide energy spectrum range can be realized, and the comprehensive performance of the desk type spectrometer is improved.

The present invention relates to the technical field of hydrogen concentration detection, and specifically discloses a trace hydrogen concentration sensing system based on TDLAS absorption spectroscopy, which is used to solve the problems of low detection sensitivity, narrow linear range, large system drift and dependence on external calibration in TDLAS hydrogen detection. The system comprises a laser emission module and a photoelectric detection module, wherein the laser emission module and the photoelectric detection module are connected via a dual-light path absorption module, the photoelectric detection module is connected to a harmonic extraction module, the harmonic extraction module is connected to a normalization processing module, and the normalization processing module is connected to a concentration inversion module. The present invention realizes high linearity, high sensitivity, and calibration-free concentration detection of hydrogen within 0.01% to 100% by constructing a symmetrical dual-light path structure, adopting a harmonic signal normalization and differential compensation algorithm, and combining a high-pressure reference gas cell with a segmented fitting model, thereby improving the trace hydrogen identification capability.

The invention discloses a natural gas calorific value test result correction method, system, equipment and medium, and relates to the technical field of natural gas analys.The method comprises the steps that according to the initial calorific value, the carbon dioxide content and the relative density obtained through testing and pressure data and temperature data of a test point, the first nitrogen content is obtained through calculation based on an S-GERG88 state equation; calculating a first calorific value by using the first nitrogen content and the initial calorific value, and performing iterative calculation according to the first calorific value to obtain a second nitrogen content until the absolute value of the difference between the second nitrogen content and the first nitrogen content is smaller than a preset value; determining the first calorific value corresponding to the obtained second nitrogen content as a target calorific value; through an iterative algorithm, the accuracy of a natural gas calorific value test result and a natural gas working condition compression factor calculation result through the laser absorption spectrometry can be greatly improved, and then the path reliability and applicability of natural gas energy metering through the laser absorption spectrometry are improved.

The present invention relates in one aspect to an absorption spectroscopy apparatus for measuring one or more gases in an atmosphere, wherein the apparatus comprises a wavelength-tunable laser source, a control circuit configured to provide an electrical drive current to the wavelength-tunable laser source; wherein the control circuit is configured to create the electrical drive current as a modulated drive current, wherein the modulated drive current alternates between at least a first and a second drive current, the first drive current configured to cause the wavelength-tunable laser source to emit laser radiation at a first wavelength and the second drive current configured to cause the wavelength-tunable laser source to emit laser radiation at a second wavelength, different from the first wavelength, and wherein the modulated drive current defines a sequence of pulses, each pulse having a non-rectangular pulse shape.

The invention provides a combustion temperature and component concentration rapid imaging measurement method based on frame rate increase, a high-frame-rate laser-induced fluorescence image is obtained by using a deep learning model, and high-speed imaging of combustion temperature and component concentration is realized by fusing laser absorption spectrum data. A flame turbulence image is obtained according to fluid mechanics simulation, a fluorescence image frame interpolation model is obtained through training, and a high-frame-rate fluorescence image is generated through low-speed laser-induced fluorescence data. Obtaining temperature distribution of a combustion field by using laser absorption spectrum data, and substituting the temperature distribution into a fluorescence model satisfied by fluorescent molecules / free radical groups to obtain high-frame-rate gas molecule / free radical group concentration distribution; the concentrations of other products are solved according to a reaction kinetic equation, and the combustion field temperature and a multi-component concentration image are solved through iterative calculation. The frame rate of low-speed fluorescence data is increased according to turbulence motion estimation, the response speed of temperature and concentration distribution imaging is increased, and the method has wide application prospects in the field of combustion reaction monitoring research.

The invention relates to the technical field of microbe traceability analysis, in particular to a microbe traceability analysis method based on an infrared absorption spectrum and a database, and the method comprises the following steps: acquiring absorbance spectral data: acquiring background spectral data for multiple times, performing background correction, acquiring spectral data of a sample containing a strain, and finally calculating the absorbance spectral data; preprocessing the absorbance spectrum data: smoothing the absorbance spectrum data by adopting an SG smoothing algorithm, and calculating a first-order derivative or a second-order derivative of the smoothed absorbance spectrum data to obtain an absorbance spectrum data set; spectral range selection: presetting different spectral ranges, and selecting different spectral ranges for analysis according to requirements; analyzing the similarity of the strains: analyzing the similarity of the absorbance spectral data set of the strains by adopting an improved hierarchical clustering algorithm; bacterial strain traceability analysis: determining a classification threshold by adopting a threshold determination algorithm, and judging microorganism traceability information; the traceability analysis precision is high, and the reliability, the stability and the practicability are high.

The embodiment of the invention provides a method for determining initial parameters of a transient absorption spectrum kinetics curve, and the method comprises the steps: obtaining an initial absorption point and an absorption attenuation termination point of the transient absorption spectrum kinetics curve, and determining a curve segment between the initial absorption point and the absorption attenuation termination point as a total absorption attenuation interval; carrying out weighting processing on a first-order derivative and a second-order derivative of the transient absorption spectrum dynamic curve to obtain a weighted curvature value sequence; the first N-1 weighted curvature values are selected from the weighted curvature value sequence from large to small, and the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to curve fitting orders according to sampling points corresponding to the first N-1 weighted curvature values; and determining an initial parameter based on a quantitative relationship of 1 / e of the absorption intensity attenuated to the corresponding interval starting point in each absorption attenuation interval in the exponential fitting model, wherein the quantitative relationship is that the absorption intensity at the interval starting point in each absorption attenuation interval is attenuated to the absorption intensity at the corresponding interval starting point. And the fitting efficiency and accuracy of the dynamic curve are improved.

Laser absorption spectroscopy using multipass absorption based on multi-plane light conversion is a very sensitive chemical sensing technique to determine the molecular composition and concentration of a sample, especially a gas sample. To achieve a long optical path length while keeping the detector small, many trace gas sensors rely on multipass absorption cells in which the beam is reflected multiple times. The novel approach of the present invention consists in using multi-plane light conversion (MPLC) phase plates as reflectors in such multipass absorption cells.

The invention provides an X-ray absorption spectrum characterization system and an X-ray absorption spectrum characterization method for electrochemical reaction under a high-current working condition. A high-current electrochemical workstation provides current density not lower than that of a working condition electrolytic tank; the working condition electrolytic tank comprises a working electrode chamber and a counter electrode chamber which are oppositely arranged, and an ion exchange membrane arranged between the working electrode chamber and the counter electrode chamber; the working electrode chamber comprises a current-conducting plate made of a metal sheet, a working electrode loaded with a catalyst is arranged on one side, facing the ion exchange membrane, of the current-conducting plate, and a hollow flow channel is formed in the central area of the working electrode chamber; the working electrode chamber further comprises an X-ray window sheet for transmission of incident X-rays and fluorescent X-rays generated by the catalyst; the counter electrode chamber is provided with an electrolyte flow channel, and a counter electrode is arranged on one side, facing the ion exchange membrane, of the counter electrode chamber; and the electrolyte control system is used for realizing circulating flow of the electrolyte. Under the working conditions of high current density, strong bubble effect and high X-ray absorption, in-situ, real-time and high signal-to-noise ratio characterization of the microstructure of the catalyst can be realized.

The invention relates to an adiabatic thermal device and method based on laser absorption spectrum tomography, which are suitable for application scenes requiring high precision, high sensitivity, dynamic quick response and lithium battery thermal runaway gas production temperature data measurement. The invention designs a battery thermal runaway measuring device combining thermal insulation heat and tunable semiconductor laser absorption spectroscopy (TDLAS) tomography, and the thermal runaway of the lithium battery can be measured by accurately measuring and reconstructing data signals of a two-dimensional temperature field of gas produced by the thermal runaway of the lithium battery and combining the gas production pressure, the temperature of the lithium battery and current and voltage data. And high-precision and high-sensitivity dynamic measurement of the thermal runaway process of the lithium battery is realized. The method solves the problems that a traditional temperature measurement method cannot realize lithium battery thermal runaway gas production temperature space distribution measurement and gas temperature measurement dynamic response lags behind, and provides support for lithium battery thermal runaway mechanism research.

The invention discloses a gas concentration measuring method and device. The gas concentration measuring method comprises the steps that a control module controls a driving module to output scanning driving signals of at least two scanning periods to a laser; the laser emits an optical signal according to the scanning driving signal; the photoelectric detector receives the attenuated light signal absorbed by the gas to be detected and converts the attenuated light signal into an electric signal; the control module determines the concentration of the to-be-detected gas in the first scanning period according to the electric signal of the first scanning period; when the concentration of the to-be-detected gas in the first scanning period is smaller than a first set threshold value, the concentration of the to-be-detected gas in the second scanning period is determined according to the electric signal in the second scanning period on the basis of the wavelength modulation spectrum WMS technology, and when the concentration of the to-be-detected gas in the first scanning period is larger than or equal to the first set threshold value, the to-be-detected gas is detected. And determining the concentration of the to-be-detected gas in the second scanning period based on a direct absorption spectrum (DAS) technology according to the electric signal in the second scanning period. According to the invention, the problem that high sensitivity and full scale are difficult to consider in the existing gas detection technology can be solved.

This invention provides a gas detection method based on absorption spectroscopy, comprising the following steps: (A1) introducing multiple concentration standard gases into a gas cell and adjusting the pressure within the gas cell to obtain the concentration values ​​C of the multiple concentration standard gases at different pressures. 仪 (A2) Fit the pressure P of the same standard gas to obtain the pressure fitting parameters P′ and C corresponding to the standard gas. 标 It is the nominal concentration of the standard gas; (A3) for the nominal concentration C of the standard gas 标 and its corresponding pressure fitting parameters P The pressure fitting parameters P′ and nominal concentration C are processed to obtain the pressure fitting parameters P′ and C′. 标 Establish and store the correspondence between them; (A4) Introduce the sample gas into the gas cell and obtain the sample gas pressure P in the gas cell. 测 The instrument concentration C of the sample gas was obtained using absorption spectroscopy. 测 The concentration P0 is obtained as atmospheric pressure; (A5) Substituting the concentration C into the corresponding relationship, we obtain the P corresponding to concentration C. 实 Thus, the concentration of the sample gas is obtained. This invention has the advantages of small detection error.

The invention relates to a laser methane detection module and a detector thereof, and belongs to the technical field of hazardous gas detection. The detection module comprises a detection module, an anti-attachment module and a processing module. The detection module monitors the methane concentration in the environment in real time through a laser and a first photoelectric detector; the anti-adhesion module monitors and reduces oil stain adhesion by using heating glass, LED lamp beads and a second photoelectric detector; and the processing module realizes signal processing, temperature control and alarm prompt through the photoelectric conversion unit, the processor unit and the temperature control unit. The detector is miniaturized in overall design, low in cost and suitable for being used in small spaces such as household kitchens. High-precision methane detection is realized through a laser absorption spectrum technology, the influence of oil stains on the performance of the detection device is effectively solved by combining with the anti-adhesion module, the service life of the device is prolonged, the maintenance cost is reduced, and the requirements of household users on safety, reliability and easy maintenance of the methane detection device are met.

The invention belongs to the field of soil dissolved organic matter analysis, and provides a multispectral-based DOM detection and reclamation influence evaluation method, which comprises the following steps: step 1, collecting dry farmland soil samples of different reclamation years, and obtaining soil column samples of a plough layer, a plow pan and subsoil; 2, extracting, centrifuging and filtering the soil sample to obtain a DOM solution; 3, detecting the DOM solution by adopting an ultraviolet-visible absorption spectrum; step 4, adopting a three-dimensional fluorescence spectrum and combining parallel factor analysis to obtain fluorescence components and source characteristics of the DOM solution; step 5, analyzing molecular composition and characteristic parameters of the DOM solution by adopting solid-phase extraction in combination with Fourier transform ion cyclotron resonance mass spectrometry; and step 6, based on the detection data in the steps 3-5, evaluating the influence of reclamation years on the composition, structure and degradation characteristics of the DOM. According to the method, multi-dimensional detection of soil DOM is realized through a multi-spectrum and mass spectrum combined technology, and DOM is comprehensively analyzed from a macrostructure to molecular composition.

The invention relates to the technical field of gas detection, and provides an LNG (Liquefied Natural Gas) dual-fuel ship exhaust gas monitoring device and a cross interference correction method thereof, synchronous detection of SO2 (0-1500ppm), CO2 (0-30%), CH4 (0-1500ppm) and NO (0-1500ppm) is realized by adopting optical detection principles such as ultraviolet differential absorption, non-dispersive infrared absorption and tunable semiconductor laser absorption spectroscopy, the error is controlled within + / -2% FS, and the detection accuracy is high. And the response time does not exceed 30s. The device realizes simultaneous accurate detection of LNG dual-fuel characteristic gas, and has the advantages of high detection precision, fast response speed, simple operation and maintenance, relatively low cost and strong cross interference resistance of gas under complex working conditions.

The invention discloses a calibration-free laser absorption spectrum signal processing method based on double spectral lines, which comprises the following steps of: utilizing a polynomial fitting algorithm and a multi-peak analysis algorithm and combining known wavelengths or wave number positions of two adjacent spectral lines of a molecular absorption spectral line; according to the invention, rapid pickup of original light intensity background signals of a laser light source and absolute calibration of emission wavelength of a laser in a tunable laser absorption spectrum system are realized respectively, and the defect that background signals are obtained by using high-purity nitrogen or zero air in a traditional method is overcome. The method has the advantages that the response time is short, the reliability is high, and the reliability problem of long-term measurement results of a tunable laser absorption spectrum technology or a gas sensor in an actual external field environment is effectively solved; the important defects in the prior art are overcome, and the practical value is wide.

The invention belongs to the technical field of combustion diagnosis and photoelectric detection, and discloses a power plant hearth gas concentration simultaneous measurement device and method based on a laser absorption spectrum, and the device comprises a first laser, a second laser and a laser pen; output light of the first laser, the second laser and the laser pen is combined by the optical fiber beam combiner, then sent to the combustion chamber, incident to the spherical reflector, then reflected and focused by the spherical reflector, and then received by the photoelectric detector after stray light is filtered by the filter; the spherical reflector, the filter and the photoelectric detector are fixedly arranged on the moving mechanism, and the moving mechanism is arranged on the two-dimensional electric translation table; the imaging module is used for imaging light spots on the spherical reflector and sending the light spots to the control module; the control module is used for controlling the imaging result to drive the two-dimensional electric translation stage to move in two dimensions, and then the light spot imaging position on the spherical reflector is controlled to be located at the center of the spherical reflector. The multi-gas concentration can be measured at the same time, and the measurement precision is high.

The invention discloses a method and a device for measuring the breakthrough pressure of a low-permeability cap based on absorption spectrum sensing. The measuring device comprises a confining pressure injection module, a data monitoring module, a return pressure setting module, an absorption spectrum sensing module, a rock core holder module and a pore pressure injection module. According to the invention, the breakthrough pressure of the low-permeability cap layer can be tested, the test work can be reliably and efficiently completed, and a pressure signal and an absorption spectrum signal are comprehensively utilized; the absorption spectrum is innovatively applied to the breakthrough pressure test, the rock sample breakthrough moment can be accurately and effectively judged, the sensitivity limitation and delay of pressure monitoring in the low-permeability cover layer test are avoided, and a good detection and tracking system is provided for breakthrough pressure calculation, breakthrough position and form change of displacement fluid; meanwhile, according to the gas monitoring function, the process and efficiency of gas breaking through the rock core can be monitored in real time to a certain extent.

The invention relates to the technical field of spectral measurement and analysis, and discloses an in-situ cell for rapid and continuous synchrotron radiation X-ray absorption spectrum measurement, the in-situ cell comprises a housing 1, one side of the housing 1 is provided with two through holes, and a counter electrode and a reference electrode are respectively fixed in the two through holes; the first shell and the second shell are correspondingly arranged, and square optical windows are arranged in the center of the second shell and the center of the first shell; the first shell and the second shell are each provided with a hole channel, the two hole channels are located on the two sides of the square optical window respectively, and a working electrode is fixedly arranged between the second shell and the first shell. The in-situ synchrotron radiation X-ray absorption spectrum measuring device is suitable for in-situ synchrotron radiation X-ray absorption spectrum measurement in a time-resolved energy dispersion / transmission mode, and through real-time supply and circular flow of the electrolyte on the surface of the working electrode, the uniformity of the X-ray penetrating through a solution layer is ensured, the elimination of product gas is accelerated, the influence of solution disturbance on a test signal is reduced, and the test stability is improved.

This invention discloses a method for detecting polycyclic aromatic hydrocarbons (PAHs) based on ultraviolet fluorescence and absorption spectroscopy, comprising: Step 1, acquiring the ultraviolet absorption spectrum and the fluorescence emission spectrum of a water sample under ultraviolet light excitation; Step 2, analyzing the corresponding CDOM fluorescence spectrum using the ultraviolet absorption spectrum obtained in Step 1; Step 3, subtracting the CDOM fluorescence spectrum obtained in Step 2 from the fluorescence emission spectrum obtained in Step 1 to obtain a mixed fluorescence spectrum containing multiple PAHs; Step 4, performing multivariate fitting on the mixed fluorescence spectrum obtained in Step 3 to obtain the type and concentration of each PAH in the water sample. This invention also provides a PAH detection device. The method provided by this invention is simple to operate and can directly detect raw water samples, thereby obtaining more accurate PAH detection results.

The invention relates to a method for realizing transient absorption full polarization state measurement based on Stokes parameters. The method is suitable for accurately representing detection light absorption polarization state change caused by pump light excitation. According to the method, a femtosecond pulse generation module is used for generating a pump light and probe light pulse sequence, and the pump light and probe light pulse sequence is modulated by a femtosecond pulse modulation module and then used for exciting a sample and detecting signal changes. The polarization state of the detection light signal is changed through the Stokes parameter modulation module, and finally the detection light signal is collected by the time resolution signal acquisition module. Stokes parameters at different delay moments are calculated by recording the change of the light intensity of the probe light in the on / off state of the pump light, and polarization information such as the degree of polarization, the azimuth angle and the elliptic polarization is further obtained. The method combines a transient absorption spectrum technology and a polarization modulation technology, has time resolution and polarization resolution capabilities, is suitable for research on anisotropic and chiral polarization sensitive samples and the like, and can be widely applied to polarization related fields such as material research and molecular optical analysis.

A method suitable for controlling polymerization reactions in resin manufacturing is provided. A manufacturing method comprising a step of causing reactants to undergo a polymerization reaction, the manufacturing method including measuring at a frequency of 9400–4500 cm⁻¹ －1 The process includes a spectral determination step that uses near-infrared absorption spectroscopy of the polymerization reaction mixture within a certain range to determine the extent of the polymerization reaction, and a viscous behavior determination step that uses the viscous behavior of the polymerization reaction mixture to determine the extent of the polymerization reaction.

The utility model belongs to the technical field of optical feedback cavity enhanced laser absorption spectrum, and particularly relates to a dynamic phase pneumatic control system based on optical feedback cavity enhanced laser spectrum. In order to provide a dynamic phase adjustment pneumatic control system which does not influence light path collimation, a Fabry-Perot (F-P) cavity is adopted, a distributed feedback type diode laser is used as a light source, the laser and the F-P cavity are subjected to mode matching through a matching lens, a feedback phase is controlled through an adjusting element, and the optical path collimation is not influenced. The incident power and the feedback rate are controlled through the lambda / 2 wave plate, the polarization splitting prism and the lambda / 4 wave plate, then the laser is coupled to enter the F-P cavity and finally is driven into the photoelectric detector through the focusing lens, and the amplitude of the transmitted laser signal is detected.

A 2-amino-5-substituted-1,3,4-oxadiazole is used to identify Cr(VI). A test solution is prepared using the 2-amino-5-substituted-1,3,4-oxadiazole. An anionic solution is added to the test solution, and Cr(VI) is identified by naked-eye observation and UV-visible absorption spectroscopy. The method demonstrates excellent selectivity for Cr(VI) identification, with no interference from other ions, enabling better detection of Cr(VI) in the environment.

The utility model relates to gas detection technical field, the utility model provides a kind of LNG dual-fuel ship exhaust monitoring device, using ultraviolet differential absorption, non-dispersed infrared absorption and tunable semiconductor laser absorption spectroscopy etc. Optical detection principle realizes the synchronous detection of four kinds of gases SO2 (0~1500ppm), CO2 (0~30%), CH4 (0~1500ppm) and NO (0~1500ppm), error is controlled within ±2%FS, response time is not more than 30s. Realize LNG dual-fuel characteristic gas accurate detection simultaneously, with the advantages of high detection precision, fast response speed, simple operation, relatively low cost and strong gas cross-interference resistance ability under complex working conditions.

1. The name of the design product: high-precision transient absorption spectrum detection device. 2. The use of the design product: for ultrafast time-resolved spectral detection, analyzing the transient absorption characteristics of materials after light excitation, suitable for kinetic studies in the fields of chemistry, materials science, biomedicine, etc. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view 1.

The present invention discloses a photo-generated chiral radical molecule based on a triarylamine derivative with circularly polarized luminescence properties, and its preparation and application. It is prepared by subjecting tris(4-aminophenyl)amine to an amide condensation reaction with an aryl-containing chiral isocyanate or an aryl-containing chiral carboxylic acid. The triarylamine derivative molecule of the present invention has the characteristics of being easy to generate and detect chiral radicals. In addition to being detected by ultraviolet-visible absorption spectroscopy and CD spectroscopy, the generation of radicals can also be judged by color change. The planarization of the conformation of the triarylamine molecule itself after the generation of radicals makes it easy to undergo self-aggregation, thereby amplifying the chiral signal. The positive charge carried can also interact with other negatively charged molecules through charge interaction to generate chiral transfer or induce self-assembly. The amide bond and urea bond components contained in the molecule enable the regulation of hydrogen bond interaction and hydrophilic-hydrophobic effect by solvents to change the circularly polarized luminescence intensity and direction brought by its aromatic group part.

The utility model provides a laser gas telemetering system based on remote calculation and control, which comprises a laser receiving and transmitting optical path passing through target gas, and a semiconductor laser and an aiming laser in the laser receiving and transmitting optical path are connected with a laser driving module. A detection laser beam emitted by the laser receiving and transmitting optical path penetrates through target gas and then is transmitted to the photoelectric conversion module, the laser driving module and the photoelectric conversion module are both connected with the data conversion and communication module, and the data conversion and communication module is connected with the remote calculation and control module and the display alarm module. According to the utility model, a wireless data communication technology, a remote calculation and control technology, a tunable laser absorption spectrum technology and a laser remote measurement technology are fused, the problems of high false alarm rate, slow data calculation and the like of the existing detection system are solved, and the monitoring and early warning requirements of high detection speed, high detection precision and few false alarms are met.

An apparatus comprising a compact folded path cell for optical gas detection and / or measurement utilizing gas absorption spectroscopy. The apparatus includes an electromagnetic radiation source, a gas sample cell housing a reflector, and a detector for electromagnetic radiation. The source and detector are positioned between the reflector elements in a configuration that reflects the radiation away from the source and detector until the reflected radiation has a suitable optical path length, and then reflects the radiation towards the detector. Using spectroscopic analysis, the presence of at least one gas species in a gas sample can be determined and / or at least one parameter can be measured.