Nano-computed tomography(Nano-CT)is an emerging,high-resolution imaging technique.However,due to their low-light properties,tabletop Nano-CT has to be scanned under long exposure conditions,which the scanning process ...Nano-computed tomography(Nano-CT)is an emerging,high-resolution imaging technique.However,due to their low-light properties,tabletop Nano-CT has to be scanned under long exposure conditions,which the scanning process is time-consuming.For 3D reconstruction data,this paper proposed a lightweight 3D noise reduction method for desktop-level Nano-CT called AAD-ResNet(Axial Attention DeNoise ResNet).The network is framed by theU-net structure.The encoder and decoder are incorporated with the proposed 3D axial attention mechanism and residual dense block.Each layer of the residual dense block can directly access the features of the previous layer,which reduces the redundancy of parameters and improves the efficiency of network training.The 3D axial attention mechanism enhances the correlation between 3D information in the training process and captures the long-distance dependence.It can improve the noise reduction effect and avoid the loss of image structure details.Experimental results show that the network can effectively improve the image quality of a 0.1-s exposure scan to a level close to a 3-s exposure,significantly shortening the sample scanning time.展开更多
Considering the complementarity of synchrotron radiation SAXS and nano-CT in the pore structure detection range,synchrotron radiation SAXS and nano-CT methods were combined to characterize the nano-to micropore struct...Considering the complementarity of synchrotron radiation SAXS and nano-CT in the pore structure detection range,synchrotron radiation SAXS and nano-CT methods were combined to characterize the nano-to micropore structure of two bituminous coal samples.In mesopores,the pore size distribution curves exhibit unimodal distribution and the average pore diameters are similar due to the affinity of metamorphic grades of the two samples.In macropores,the sample with higher mineral matter content,especially clay mineral content,has a much higher number of pores.The fractal dimensions representing the pore surface irregularity and the pore structure heterogeneity were also characterized by synchrotron radiation SAXS and nano-CT.The fractal dimensions estimated by both methods for different pore sizes show consistency and the sample with smaller average pore diameters has a more complex pore structure within the full tested range.展开更多
X-ray computed tomography at the nanometer scale （nano-CT） offers a wide range of applications in scientific and industrial areas. Here we describe a reliable, user-friendly, and fast software package based on LabVI...X-ray computed tomography at the nanometer scale （nano-CT） offers a wide range of applications in scientific and industrial areas. Here we describe a reliable, user-friendly, and fast software package based on LabVIEW that may allow us to perform all procedures after the acquisition of raw projection images in order to obtain the inner structure of the investigated sample. A suitable image alignment process to address misalignment problems among image series due to mechanical manufacturing errors, thermal expansion, and other external factors has been considered, together with a novel fast parallel beam 3D reconstruction procedure that was developed ad hoc to perform the tomographic reconstruction. We have obtained remarkably improved reconstruction results at the Beijing Synchrotron Radiation Facility after the image calibration, the fundamental role of this image alignment procedure was confirmed, which minimizes the unwanted blurs and additional streaking artifacts that are always present in reconstructed slices. Moreover, this nano-CT image alignment and its associated 3D reconstruction procedure are fully based on LabVIEW routines, significantly reducing the data post-processing cycle, thus making the activity of the users faster and easier during experimental runs.展开更多
Full-field transmission X-ray microscopy(TXM)is a powerful non-destructive three-dimensional(3D)imaging method with a nanoscale spatial resolution that has been used in most synchrotron facilities worldwide.An in-hous...Full-field transmission X-ray microscopy(TXM)is a powerful non-destructive three-dimensional(3D)imaging method with a nanoscale spatial resolution that has been used in most synchrotron facilities worldwide.An in-house-designed TXM system was constructed at the BL18B 3D nanoimaging beamline at the Shanghai Synchrotron Radiation Facility.The beamline operates from 5 to 14 keV and enables 20 nm spatial resolution imaging.The characterization details of the beamline are described in this paper.The performances in terms of spatial resolution,nano-CT,and nano-spectral imaging of the TXM beamline are also presented in this article.展开更多
Combined with NMR,core experiment,slim-tube tests,nano-CT and oil composition analysis,the mechanism of CO(2) enhanced oil recovery had been studied.CO_(2) flooding under supercritical state could achieve higher oil r...Combined with NMR,core experiment,slim-tube tests,nano-CT and oil composition analysis,the mechanism of CO(2) enhanced oil recovery had been studied.CO_(2) flooding under supercritical state could achieve higher oil recovery.In the process of crude oil displaced by supercritical CO2,the average oil recovery was 46.98% at low displacement pressures and 73.35% at high displacement pressures.The permeability of cores after CO2 flooding was only 28%-64% of those before flooding.As to the expelled oil,the contents of asphaltenes and non-hydrocarbons decreased,and saturated hydrocarbons of above C25 were absent in some samples,indicating that they had been retained in cores as demonstrated by CT and NMR experiments.In slim-tube tests,the heavy components of oil were expelled when the pressure increased to 30 MPa.There was a reasonable bottom hole pressure(BHP) below which the heavy components driven out from the far-well zone would deposit in the near-well zone,and when the pressure was too high,the nonhydrocarbon detention may cause block.The smaller throat and worse physical properties the porous media had,the higher displacement pressure would be required to achieve a good oil displacement efficiency.The increase in displacement pressure or time of interaction between oil and CO2 could effectively enhance oil recovery.展开更多
This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the...This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.展开更多
基金supported by the National Natural Science Foundation of China(62201618).
文摘Nano-computed tomography(Nano-CT)is an emerging,high-resolution imaging technique.However,due to their low-light properties,tabletop Nano-CT has to be scanned under long exposure conditions,which the scanning process is time-consuming.For 3D reconstruction data,this paper proposed a lightweight 3D noise reduction method for desktop-level Nano-CT called AAD-ResNet(Axial Attention DeNoise ResNet).The network is framed by theU-net structure.The encoder and decoder are incorporated with the proposed 3D axial attention mechanism and residual dense block.Each layer of the residual dense block can directly access the features of the previous layer,which reduces the redundancy of parameters and improves the efficiency of network training.The 3D axial attention mechanism enhances the correlation between 3D information in the training process and captures the long-distance dependence.It can improve the noise reduction effect and avoid the loss of image structure details.Experimental results show that the network can effectively improve the image quality of a 0.1-s exposure scan to a level close to a 3-s exposure,significantly shortening the sample scanning time.
基金financially sponsored by the National Natural Science Foundation of China(Grant Nos.U1910206,51861145403,51874312,52004293)China Postdoctoral Science Foundation(No.2018M641526)+2 种基金Yue Qi Distinguished Scholar Project of China University of Mining&Technology(Beijing)Fundamental Research Funds for the Central UniversitiesFund of China Scholarship Council and the Open Project Program of Key Laboratory of Deep Earth Science and Engineering(Sichuan University),Ministry of Education(No.DESE 202004)。
文摘Considering the complementarity of synchrotron radiation SAXS and nano-CT in the pore structure detection range,synchrotron radiation SAXS and nano-CT methods were combined to characterize the nano-to micropore structure of two bituminous coal samples.In mesopores,the pore size distribution curves exhibit unimodal distribution and the average pore diameters are similar due to the affinity of metamorphic grades of the two samples.In macropores,the sample with higher mineral matter content,especially clay mineral content,has a much higher number of pores.The fractal dimensions representing the pore surface irregularity and the pore structure heterogeneity were also characterized by synchrotron radiation SAXS and nano-CT.The fractal dimensions estimated by both methods for different pore sizes show consistency and the sample with smaller average pore diameters has a more complex pore structure within the full tested range.
基金Supported by Major State Basic Research Development Program(2012CB825800)Science Fund for Creative Research Groups(11321503)+2 种基金Knowledge Innovation Program of The Chinese Academy of Sciences(KJCX2-YW-N42)National Natural Science Foundation of China(11179004,10979055,11205189,11205157)Fundamental Research Funds for the Central Universities(WK2310000021)
文摘X-ray computed tomography at the nanometer scale （nano-CT） offers a wide range of applications in scientific and industrial areas. Here we describe a reliable, user-friendly, and fast software package based on LabVIEW that may allow us to perform all procedures after the acquisition of raw projection images in order to obtain the inner structure of the investigated sample. A suitable image alignment process to address misalignment problems among image series due to mechanical manufacturing errors, thermal expansion, and other external factors has been considered, together with a novel fast parallel beam 3D reconstruction procedure that was developed ad hoc to perform the tomographic reconstruction. We have obtained remarkably improved reconstruction results at the Beijing Synchrotron Radiation Facility after the image calibration, the fundamental role of this image alignment procedure was confirmed, which minimizes the unwanted blurs and additional streaking artifacts that are always present in reconstructed slices. Moreover, this nano-CT image alignment and its associated 3D reconstruction procedure are fully based on LabVIEW routines, significantly reducing the data post-processing cycle, thus making the activity of the users faster and easier during experimental runs.
基金supported by the National Key Research and Development Program of China(Nos.2021YFA1600703,2021YFF0701202,and 2021YFA1601001)the National Natural Science Foundation of China(Nos.12275343 and U1932205)。
文摘Full-field transmission X-ray microscopy(TXM)is a powerful non-destructive three-dimensional(3D)imaging method with a nanoscale spatial resolution that has been used in most synchrotron facilities worldwide.An in-house-designed TXM system was constructed at the BL18B 3D nanoimaging beamline at the Shanghai Synchrotron Radiation Facility.The beamline operates from 5 to 14 keV and enables 20 nm spatial resolution imaging.The characterization details of the beamline are described in this paper.The performances in terms of spatial resolution,nano-CT,and nano-spectral imaging of the TXM beamline are also presented in this article.
基金financial support from the National Science and Technology Major Project (2017ZX05013-001, 2017ZX05069003, 2017ZX05049005-004)Ministry of Science and Technology of PetroChina (2021ZZ01-03, kt2021-09-05, 2021DJ1806, 2017E-1514, 2018E-11-05)。
文摘Combined with NMR,core experiment,slim-tube tests,nano-CT and oil composition analysis,the mechanism of CO(2) enhanced oil recovery had been studied.CO_(2) flooding under supercritical state could achieve higher oil recovery.In the process of crude oil displaced by supercritical CO2,the average oil recovery was 46.98% at low displacement pressures and 73.35% at high displacement pressures.The permeability of cores after CO2 flooding was only 28%-64% of those before flooding.As to the expelled oil,the contents of asphaltenes and non-hydrocarbons decreased,and saturated hydrocarbons of above C25 were absent in some samples,indicating that they had been retained in cores as demonstrated by CT and NMR experiments.In slim-tube tests,the heavy components of oil were expelled when the pressure increased to 30 MPa.There was a reasonable bottom hole pressure(BHP) below which the heavy components driven out from the far-well zone would deposit in the near-well zone,and when the pressure was too high,the nonhydrocarbon detention may cause block.The smaller throat and worse physical properties the porous media had,the higher displacement pressure would be required to achieve a good oil displacement efficiency.The increase in displacement pressure or time of interaction between oil and CO2 could effectively enhance oil recovery.
基金This work was supported by the National Key Research and Development Program of China(Nos.2017YFA0403801,2016YFA0401302,2017YFA0206004,2018YFC1200204)the National Major Scientific Instruments and Equipment Development Project of China(No.11627901).
文摘This paper introduces some latest developments regarding the X-ray imaging methodology and applications of the X-ray imaging and biomedical application beamline(BL13W1)at Shanghai Synchrotron Radiation Facility in the past 5 years.The photon energy range of the beamline is 8–72.5 keV.Several sets of X-ray imaging detectors with different pixel sizes(0.19–24 lm)are used to realize X-ray microcomputed tomography(X-ray micro-CT)and X-ray in-line phase-contrast imaging.To satisfy the requirements of user experiments,new X-ray imaging methods and image processing techniques are developed.In vivo dynamic micro-CT experiments with living insects are performed in 0.5 s(sampling rate of 2 Hz,2 tomograms/s)with a monochromatic beam from a wiggler source and in 40 ms(sampling rate of 25 Hz,25 tomograms/s)with a white beam from a bending magnet source.A new X-ray imaging method known as move contrast X-ray imaging is proposed,with which blood flow and moving tissues in raw images can be distinguished according to their moving frequencies in the time domain.Furthermore,X-ray speckle-tracking imaging with twice exposures to eliminate the edge enhancement effect is developed.A high-precision quantification method is realized to measure complex three-dimensional blood vessels obtained via X-ray micro-CT.X-ray imaging methods such as three-dimensional X-ray diffraction microscopy,small-angle X-ray scattering CT,and X-ray fluorescence CT are developed,in which the X-ray micro-CT imaging method is combined with other contrast mechanisms such as diffraction,scattering,and fluorescence contrasts respectively.Moreover,an X-ray nano-CT experiment is performed with a 100 nm spatial resolution.Typical user experimental results from the fields of material science,biomedicine,paleontology,physics,chemistry,and environmental science obtained on the beamline are provided.
