38 results about "Chemical exchange" patented technology

The embodiment of the invention provides a CEST image super-resolution reconstruction method, medium and equipment, and the method comprises the steps: obtaining an original image and a reference image of a target object, the original image being a molecular function image collected through a chemical exchange saturation transfer imaging technology, and the reference image being an anatomical structure image collected through a magnetic resonance imaging technology; through a high-frequency, intermediate-frequency and low-frequency fusion enhancement network, extraction and fusion enhancement of corresponding high-frequency, intermediate-frequency and low-frequency characteristics are carried out on an original image and a reference image. According to the method, anatomical edge details of a reference image are captured through a high-frequency fusion enhancement network to enhance image edge details, image texture features are captured through an intermediate-frequency fusion enhancement network to enhance image texture details, image background details are enhanced through a low-frequency fusion enhancement network, and then images with enhanced frequency band information are fused. A reconstructed image with high resolution and molecular function signals is obtained, and the reconstruction precision of super-resolution reconstruction is improved.

The present disclosure provides a chemical supply apparatus of a liquid processing apparatus. The chemical supply apparatus of a liquid processing apparatus may include: a first tank and a second tank storing liquid to be supplied to the substrate processing apparatus; a liquid supply source supplying a chemical to the first tank and the second tank; a main circulation line connected to the first tank and the second tank and supplying liquid to the substrate processing apparatus; and a control unit controlling the tanks and the main circulation line to perform a flushing mode that drains the liquid accommodated in the first tank and the second tank, supplies a flushing liquid to the first tank, collects the flushing liquid to the second tank from the main circulation line, and then drains the flushing liquid.

The present disclosure provides a chemical supply apparatus of a liquid treatment apparatus. A chemical supply apparatus of a liquid processing apparatus may include: a first tank and a second tank that store a liquid to be supplied to a substrate processing apparatus; a liquid supply source that supplies a chemical to the first tank and the second tank; a main circulation line that is connected to the first tank and the second tank, and supplies a liquid to the substrate processing apparatus; and a control unit that controls the tanks and the main circulation line to execute a flushing mode that discharges the liquid contained in the first tank and the second tank, supplies flushing liquid to the first tank, and collects the flushing liquid from the main circulation line to the second tank, and then discharging the flushing fluid.

The invention provides a respiratory-gating-free free-breathing liver glycogen quantitative magnetic resonance imaging method and system, and the method comprises the steps: applying a chemical exchange saturation transfer imaging sequence to a liver region of a subject, and the imaging sequence comprises saturation pulses of a plurality of saturation frequency deviation points; a radial blade type k-space acquisition strategy is adopted to acquire magnetic resonance signal data, the radial blade type k-space acquisition strategy comprises a plurality of blades, each blade is composed of a group of parallel k-space lines, and different blades are rotationally distributed by taking the k-space center as a rotating shaft; performing image reconstruction on the acquired k space data to obtain magnetic resonance images under different saturation frequency deviations; and performing fitting analysis on the magnetic resonance image by adopting a multi-pool Lorentz model to obtain quantitative information of the liver glycogen. According to the method, the interference of respiratory movement on the CESTMRI data acquisition process can be eliminated, so that the accurate quantification of the liver glycogen in the free respiration state is realized.

The invention discloses a non-contrast agent injection tumor glucose CEST weighted imaging acquisition and post-processing method, and relates to the technical field of magnetic resonance imaging, and the method is characterized in that a 16-channel phased array coil is used on a 3.0 T MR scanner to obtain MRI; by means of the obtained MRI, a 3D glucose CEST (glucoCEST) image is obtained by means of a 3D single TSE-mDixon sequence and SPIR fat suppression; post-processing is carried out on the 3D (three-dimensional) glucoCEST image, and an MTRasym image is obtained; the change of the glucose CEST weighted signal is analyzed through MTRasym imaging, the change of the in-vivo glucose concentration is obtained, and the detection of the in-vivo glucose signal is completed. According to the magnetic resonance imaging technology based on chemical exchange saturation transfer, the contrast agent is replaced with the magnetic resonance saturation pulse for specifically inhibiting the glucose signal, in-vivo glucose signal detection can be achieved, meanwhile, the obtained image is high in resolution and low in cost, and repeated detection and clinical popularization are facilitated.

Methods and systems for performing the methods of imaging at least a part of a body are presented. The method comprises: acquiring signals by subjecting the portion of the body (10) to a chemical exchange saturation transfer (CEST) imaging protocol including radiofrequency (RF) saturation at a number of different saturation frequency offsets; defining local sets of voxels, each containing at least one voxel, which cover the anatomical portions of the imaged part of the body; generating a Z-spectrum for each set of voxels based on the combined acquired signals of the voxels for a magnetic resonance image; using a fitting model to capture the shape of the Z-spectrum and derive a basic CEST signal within each set of voxels; deriving a scaling quantity based on a selected shape parameter of the fitting model, wherein the scaling quantity decreases with increasing fluid content within local set of voxels depending on its location in the anatomical portions of the imaged part of the body; deriving a fluid- suppressed CEST contrast signal for each set of voxels based on the basic CEST signal and the scaling quantity for each set of voxels; outputting the fluid-suppressed CEST contrast signal.

The invention provides a system for producing deuterium-rich water by combining chemical exchange and liquid ammonia rectification, which comprises an ammonia A2 storage unit, an ammonia water exchange device, a liquid ammonia rectification device and a water ammonia exchange device, and three processes of ammonia water exchange, liquid ammonia rectification and water ammonia exchange are coupled and connected in series to construct a complete hydrogen isotope (deuterium) enrichment path. According to the path, deuterium is efficiently transferred from high-boiling-point raw water to a low-boiling-point ammonia medium through ammonia water exchange, low-energy-consumption and high-magnification deuterium enrichment is achieved in an N-stage rectifying tower through liquid ammonia rectification by means of the low-boiling-point characteristic of liquid ammonia, and finally high-deuteration-degree ammonia is efficiently converted back to high-deuteration-degree deuterium-enriched water through reverse water ammonia exchange. Cooperative transmission of the material flow and the isotope flow is obviously optimized, and directional and step-by-step enrichment of deuterium in the material flow process is achieved.

The invention discloses an application of lanthanide metal complexes as a 31P CEST high-field contrast agent in ATP (adenosine triphosphate) recognition, which is characterized in that a chemical exchange saturation transfer (CEST) technology is utilized, the lanthanide metal complexes (such as Eu-DO3A, Tb-DO3A, Pr-DO3A and Yb-DO3A) are used as the 31P CEST high-field contrast agent, phosphate radicals of ATP are used as large-cell signals of CEST, and the chemical exchange saturation transfer (CEST) technology is utilized to identify the ATP. According to the present invention, the phosphate radical of ATP coordinated with the lanthanide series metal complex is adopted as the CEST small pool signal, such that the 31P CEST signals of the alpha-P, the beta-P and the gamma-P three exchange sites of ATP can be obtained, the 31P CEST signals of the ATP analogues ADP (alpha-P and beta-P) and AMP can be significantly distinguished, and the problem that the ATP and the ATP analogues are difficult to distinguish by using the traditional optical and electrochemical means is solved.

The invention is suitable for the technical field of magnetic resonance chemical exchange saturation transfer imaging, and provides a magnetic resonance chemical exchange saturation transfer imaging method, device, equipment, product and storage medium. A gradient echo sequence is adopted to collect saturated water molecule signals, and the collected water molecule signals are stored in a K space; and wave control coding is introduced in the acquisition process, and a CEST image is reconstructed based on a water molecule signal of a K space. The introduction of wave control coding can reduce the scanning time. Due to the fact that the wave control coding sampling efficiency is high, a larger matrix size can be supported within the same time, high-resolution imaging is achieved, the partial volume effect can be relieved, and CEST quantitative accuracy is improved.

This application discloses a magnetic resonance chemical exchange saturation transfer imaging method, system, device, and storage medium. The method includes: applying a radio frequency saturation pulse for a first preset time to a region to be detected; applying a radio frequency echo pulse to the region to be detected and acquiring several gradient echo signals generated after activation by the radio frequency echo pulse; and using radial sampling to read the gradient echo signals along a preset direction to generate a magnetic resonance image. Through this method, this application effectively shortens the signal acquisition time by using gradient echo readings, effectively suppresses motion artifacts by using radial acquisition, and applies post-processing methods such as fitting to the acquired chemical exchange saturation transfer imaging spectral data to achieve water-lipid signal separation and extract and analyze the target signal.

The application discloses a flexible echo time water-fat separation method and system based on a main magnetic field map (B0map) and equipment, and belongs to the technical field of magnetic resonance imaging. The application combines a B0map which needs to be collected in chemical exchange saturation transfer (CEST) imaging, and proposes a new seed point selection and seed point error phase determination method. The seed point error phase determined by the method can grow a relatively accurate error vector map in space, thereby ensuring the final water-fat accurate separation. In the embodiment of the application, the proposed method is verified on a water model and pork, and ideal water-fat separation results are obtained.

The invention provides an enzyme heuristic magnetic nanoprobe and a preparation method and application thereof.The preparation method comprises the steps that gold tetrachlorate trihydrate and gadolinium acetylacetonate hydrate are dissolved in a mixed solvent of tetrahydronaphthalene and oleylamine, a reducing agent is rapidly injected under the inert atmosphere condition of 4-50 DEG C, a reaction is conducted for 30-60 min, a first non-polar solvent is used for washing, precipitation and centrifugation, and an enzyme heuristic magnetic nanoprobe is obtained; the oil-phase enzyme heuristic magnetic nanoparticles are obtained; carrying out surface hydrophilic modification on the obtained oil-phase enzyme heuristic magnetic nanoparticles in a mixed solvent system consisting of polar solvents by using hydrophilic molecules through a ligand exchange method to obtain aqueous-phase enzyme heuristic magnetic nanoparticles; the preparation method comprises the following steps: carrying out chemical amide connection reaction on aqueous-phase enzyme heuristic magnetic nanoparticles, and coupling the aqueous-phase enzyme heuristic magnetic nanoparticles with a high-specificity ligand to finish surface targeted modification, thereby obtaining the enzyme heuristic magnetic nanoprobe. According to the invention, efficient chemical exchange of water protons can be promoted, so that the magnetic resonance T1 imaging effect is obviously enhanced.

The invention relates to a germanium isotope separation method, device and system. According to the germanium isotope separation method, device and / or system, the problems that in the prior art, a germanium isotope separation method is small in scale, low in production efficiency, incapable of achieving continuous production, not suitable for industrial application and the like are solved through a chemical exchange method.

The present invention relates to the field of nuclear magnetic resonance technology, and particularly relates to a method for amplifying the intensity of nuclear magnetic resonance signals, comprising the following steps: collecting the one-dimensional nuclear magnetic resonance 1 1H spectrum and 13 13C spectrum of a sample; measuring the pulse widths of the 90-degree hard pulses of 13 13C and 1 1H of the sample; setting the intensities and durations of the z-filter gradients G1, G3 and the coherence selection gradients G2, G4; setting the spectral widths of the direct dimension and the indirect dimension; setting the central frequency of the detected hydrogen nuclei in the one-dimensional spectrum as the central frequency of the new pulse; setting the central frequency of the carbon nuclei as the irradiation decoupling central frequency and setting the decoupling power and sampling time; determining the number of sampling points n i in the indirect dimension; setting the value of the chemical shift reduction factor λ in the indirect dimension; using the INEPT pulse module to generate polarization transfer and enhance the 13 13C magnetization vector; adding n echo trains in the indirect dimension; then using the reversed INEPT module to transfer the 13 13C magnetization vector back to 1 1H; starting to collect nuclear magnetic resonance signals; performing two-dimensional Fourier transform on the signals to obtain the result.

The invention relates to a continuous separation production device for 10B isotope, which comprises a complexing tower for complexing a complexing agent and boron trifluoride and providing tower top reflux for an exchange tower group; the falling film cracking reactor is used for cracking the boron trifluoride-anisole complex, separating to obtain enriched < 10 > BF3 and providing tower bottom reflux for the exchange tower group; the exchange tower group is used for exchanging, enriching and separating < 11 > B in boron trifluoride and < 10 > B in boron trifluoride in a complex; and the natural abundance boron trifluoride gas raw material channel is laterally communicated with the tower bottom of the first exchange tower. The connection of the exchange towers in the device is relatively special, the liquid phase of the device flows according to the cross flow of 1-3-2-4 of the exchange towers, the effect of increasing the abundance gradient of liquid-phase and gas-phase 10B isotopes between the exchange towers is achieved, the chemical exchange mass transfer driving force is improved, the separation efficiency is improved, the balance time is shortened, and the separation efficiency is improved. The abundance of the obtained 10B isotope is higher, and the maximum abundance reaches 97% or above.

Systems and methods for deriving chemical exchange saturation transfer (CEST) contrast images are presented. In one aspect according to the invention, the method comprises: acquiring signals by subjecting a portion of the body (10) to a CEST imaging protocol, the CEST imaging protocol comprising RF saturation at several different saturation frequency shifts; generating a Z-spectrum from the acquired signal for each voxel in a set of voxels from the magnetic resonance image; modeling a Z-spectrum background, the Z-spectrum background comprising contributions from direct water saturation, magnetization transfer and one or more fat signal components, where parameters of the model are determined by fitting the modeled Z-spectrum background to the generated Z-spectrum for each voxel, thereby omitting regions of the Z-spectrum affected by the CEST effect; and deriving a CEST contrast image based on the modeled Z-spectrum background and the Z-spectrum generated for each voxel. The system includes a processor configured to perform the method.

An evaluation method is performed by an arithmetic circuit and includes obtainment processing (S1), evaluation processing (S2), and presentation processing (S3). The obtainment processing (S1) obtains: image information on a sectional image representing an interested section of an organism including a target section of a testis of the organism generated by use of magnetic resonance of hydrogen atoms; and concentration information on a creatine concentration in the interested section measured by use of magnetic resonance based on chemical exchange saturation transfer. The evaluation processing (S2) generates an evaluation image representing a distribution of evaluation results of a testicular function in the target section based on the concentration information. The presentation processing (S3) presents the sectional image and the evaluation image.

The application discloses a brain glioma recognition device based on a 5T multi-nuclear magnetic resonance imaging system, which comprises an amide proton imaging acquisition module for receiving a chemical exchange saturation transfer spectrum of amide protons and amide proton concentration; 1 H T2 weighted MRI images, 23 Na MRI images and total sodium concentration maps 23 Na MRI image acquisition module; for receiving 31 P MRS images and phosphorus-containing metabolite concentration of brain regions 31 P MRS image acquisition module; and a recognition module comprising a discrimination network and a segmentation network. The application inputs a sample group into the discrimination network and the segmentation network of the cross-modal data brain tumor, can recognize abnormal signals of different voxels of brain regions, and can outline the boundary of the brain glioma.

The invention belongs to the technical field of powder material preparation, and particularly relates to a method for synthesizing carbon-silicon and carbon-boron powder by using a carbon source. The heavy component mixture generated in the boron isotope separation process through a chemical exchange method is used as a novel carbon source, the problems that a traditional carbon source is high in cost and complex in technology are solved by optimizing the raw material ratio, the calcination technology and post-treatment parameters, industrial waste resource utilization is achieved, and meanwhile powder with the excellent structure and performance is prepared. The boron isotope separation heavy component mixture is used as a carbon source for the first time, waste is turned into wealth, the cost is reduced, industrial waste discharge is reduced, and the method conforms to the green chemistry concept. The invention provides an efficient, environment-friendly and controllable carbon silicon / carbon boron powder synthesis method through raw material innovation and process optimization, and has remarkable economic value and technical advantages.

The invention relates to a temperature measurement method and device based on phosphocreatine chemical exchange saturation transfer imaging. The method comprises the following steps: (1) carrying out chemical exchange saturation transfer imaging on creatine phosphate phantom at different temperatures, and calculating apparent chemical shift of creatine phosphate in the creatine phosphate phantom at different temperatures; (2) fitting the mathematical relationship between the apparent chemical shift of the creatine phosphate and the temperature of the creatine phosphate phantom; and (3) carrying out in-vivo phosphocreatine chemical exchange saturation transfer imaging on the individual to be detected, calculating the apparent chemical shift of phosphocreatine in the individual to be detected, and generating a temperature map of the biological tissue of the individual to be detected according to the mathematical relationship. The absolute temperature imaging technology based on the CEST effect of endogenous phosphocreatine and the temperature dependence of the endogenous phosphocreatine is developed, and the method has the advantages of being high in spatial resolution, high in sensitivity, non-invasive, capable of being repeated for multiple times and the like, and has good clinical conversion application and popularization prospects.

The invention provides a cracking degree on-line detection device and method for separating boron isotopes by a chemical exchange method, and the device comprises a sample on-line introduction pipeline, an absorbance detection module and a sample on-line return pipeline which are connected in sequence, an inlet of the on-line sample lead-in pipeline and an outlet of the on-line sample return pipeline are respectively connected with a process main line, so that on-line internal circulation is formed. The spectrophotometric method is mainly used for detecting the cracking degree of the boron isotope separated by the chemical exchange method on line, the sample liquid can realize internal circulation, and the detection of the cracking degree of the boron trifluoride anisole complex can be completed under the condition of not generating waste liquid, so that the operation parameters of the cracking process are accurately controlled.

The present invention relates to a temperature measurement method and device based on creatine chemical exchange saturation transfer imaging, the method comprising the following steps: (1) performing chemical exchange saturation transfer imaging on a creatine phantom and analyzing the chemical shift of creatine relative to water in the creatine phantom; (2) fitting the mathematical relationship between the chemical shift of creatine relative to water and the temperature of the creatine phantom; (3) performing chemical exchange saturation transfer imaging on creatine in a sample and analyzing the chemical shift of creatine relative to water in the sample, and calculating the sample temperature based on the mathematical relationship between the chemical shift of creatine relative to water and the temperature of the creatine phantom fitted in step (2). The measurement method uses creatine as an endogenous reference substance and utilizes the temperature dependence of the CEST effect of creatine and water to perform high spatial resolution, high sensitivity, and non-invasive absolute temperature measurement.

The invention discloses a device and a method for separating boron isotopes through direct refrigeration and low-temperature rectification, and relates to the technical field of separation. The device comprises rectifying towers, a reboiler and a compressor, a liquid-phase material is discharged to the tower top of the next-stage rectifying tower through a tower kettle of each-stage rectifying tower, and a gas-phase material is discharged to the tower kettle of the previous-stage rectifying tower through the tower top of each-stage rectifying tower. Extra heat source heat supply and cold source cooling are not needed, a large amount of cooling capacity can be obtained with a small amount of power consumption, the power consumption is only about 1 / 10 of the cooling capacity required by rectification, a large amount of low-grade cooling capacity is recycled through a circulating working medium, energy is efficiently utilized, and the energy consumption of the device is reduced; and compared with other chemical exchange rectification methods, the design of a complexing process and a cracking process is omitted, further impurity removal treatment is not needed subsequently, and the technological process is simplified.

The invention discloses a method and a system for detecting BPA based on CEST. The method comprises the following steps: acquiring an improved continuous wave-planar echo chemical exchange saturation transfer sequence; scanning the test tube model of the BPA according to the improved continuous wave-planar echo chemical exchange saturation transfer sequence, and collecting chemical exchange saturation transfer data; and analyzing the signal intensity and distribution of the BPA according to the chemical exchange saturation transfer data. In view of the fact that most human tumor microenvironments are weakly acidic or acidic, a boron drug BPA signal is difficult to directly detect by a conventional method. Meanwhile, compared with a PET method, radioactive element labeling does not need to be introduced, and efficient and accurate quantitative detection and visual expression of BPA can be achieved. The method has the advantages of being simple and convenient to operate, noninvasive, high in sensitivity and specificity and the like, and a new strategy is provided for establishment of a precise boron drug concentration measurement system.

The invention discloses a phosphate radical identification method based on a high field (greater than or equal to 5.0 T) 31P CEST. According to the phosphate radical identification method, a high field MRI system greater than or equal to 5.0 T is adopted, the signal-to-noise ratio of the 31P CEST is effectively improved, and the problem of low saturation efficiency is solved; the lanthanide metal complex accelerates chemical exchange through a paramagnetic effect and is combined with spectral line separation under a high field, so that the contrast ratio of 31P CEST is remarkably improved, the problem of spectral peak overlapping is solved, and a phosphate radical signal is distinguished from adjacent phosphorus-containing molecules. In a word, through the synergistic effect of the high-field 31P CEST technology and the lanthanide series metal complex, phosphate radical recognition is achieved, and a new direction is provided for tumor metabolism research and drug development.

The application provides a cracking degree on-line detection device and method for separating boron isotopes by chemical exchange method, and the device comprises a sample on-line introduction pipeline, an absorbance detection module and a sample on-line reflux pipeline connected in sequence, and the inlet of the sample on-line introduction pipeline and the outlet of the sample on-line reflux pipeline are connected with a process main pipeline, so as to form on-line internal circulation. The application mainly utilizes the spectrophotometry to on-line detect the cracking degree of the boron isotopes separated by the chemical exchange method, the sample liquid can realize internal circulation, the detection of the cracking degree of the boron trifluoride anisole complex can be completed without generating waste liquid, and therefore the operation parameters of the cracking process can be accurately controlled.

A method for chemical exchange saturation transfer (CEST) MRI using an average saturation efficiency filter (ASEF) / adjustment of rotation and saturation effects (AROSE) includes: applying a first RF pulse train including a high duty cycle, the first RF pulse causing magnetization of exchangeable protons based on saturation and / or rotation effects, transferred to a water pool of a target structure; discontinuing application of the first RF pulse train; acquiring a first water MR signal; applying a second RF pulse train including a low duty cycle, the second RF pulse train causing magnetization of the target molecules based at least in part on saturation transfer and either minimizing rotation transfer with bipolar pulses or adjusting rotation transfer with selected flip angles; discontinuing application of the second RF pulse train; acquiring a second water MR signal; and generating ASEF / AROSE signal representing a difference between the first and second water MR signals.

The application provides a motion self-correcting kidney chemical exchange saturation transfer imaging method and system, belongs to the CEST imaging technical field, and the imaging method comprises the following steps: collecting an original image, dividing a respiratory state, reconstructing an image, image registration and fusion, data post-processing and signal quantification, and the imaging system comprises various modules for realizing the imaging method; through CEST sequence design of 112.5° radial sampling, k-space reading of fast field echo (TFE) is utilized, the signal of 0.1-0.5 Hz at the center of k-line is extracted as a respiratory signal, the respiratory state is divided by using the respiratory signal and k-space data is split, the images corresponding to different respiratory states are reconstructed, finally, the final CEST-MRI image is obtained through image registration and average fusion of the images of different respiratory states, the signal-to-noise ratio, saturation efficiency and signal accuracy are ensured, and the problem that the respiratory motion influences CEST signal quantification when chemical exchange saturation transfer imaging (CEST-MRI) of the kidney is performed under free breathing is solved.

This invention belongs to the field of biomedical technology, specifically relating to a hyperpolarized... 129 Xe magnetic resonance molecular probe and its preparation method. This probe uses ZIF-8 as a template and 2-aminoimidazole as a ligand exchange component. The molecular probe is formed by the interaction of a monomer with a ligand in a methanol solution. The monomer is synthesized from 2-methylimidazole and zinc nitrate hexahydrate. 129 Xe molecular cage ZIF-8, wherein the monomer ZIF-8 is modified by post-synthetic modification with a 2-aminoimidazolium ligand. 129 Xe molecular cage, i.e., hyperpolarization 129 Xe magnetic resonance molecular probe. The principle of this molecular probe is as follows: ZIF-8 is a Zn... 2+ The metal-organic framework (MOF) formed by coordination with the N atom on the 2-methylimidazolium ring exhibits acid sensitivity and pH responsiveness. Through post-synthetic modification (PSM) of ZIF-8, ligand exchange between 2-aminoimidazolium and ZIF-8 is achieved, resulting in a novel ZIF-8-AIM molecular probe for hyperpolarization. 129 Xe chemical exchange saturation transfer will produce a new signal different from the original ZIF-8, which can be used for magnetic resonance molecular probes.

The invention discloses a method for efficiently producing stable isotope carbon-13, and belongs to the technical field of isotope separation. The method for efficiently producing the stable isotope carbon-13 comprises the following steps: CO2 chemical exchange pretreatment: introducing a CO2 raw material gas and an amine organic solution into a CO2 chemical exchange tower in a gas-liquid countercurrent manner for chemical exchange, discharging enriched < 18 > O as a gas phase from the tower top, and obtaining a < 13 > C-enriched carbamate liquid phase at the tower bottom. The carbamate liquid phase is subjected to heating decomposition, and CO2 pretreatment gas enriched with 13C is obtained. And reducing the CO2 pretreatment gas to form CO gas, and carrying out low-temperature rectification to obtain a 13CO product enriched with 13C. According to the method, pretreatment and pre-enrichment are carried out before low-temperature rectification of CO, most of < 18 > O is removed, the influence of < 12 > C < 18 > O on low-temperature rectification can be avoided, the problem that the content of oxygen < 18 > in a product is high is solved, and meanwhile the production cost is greatly reduced.