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
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
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
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
Diffusion is an important mass transfer mode of tight sandstone gas. Since nano-pores are extensively developed in the interior of tight sandstone, a considerable body of research indicates that the type of diffusion ...Diffusion is an important mass transfer mode of tight sandstone gas. Since nano-pores are extensively developed in the interior of tight sandstone, a considerable body of research indicates that the type of diffusion is mainly molecular diffusion based on Fick＇s law. However, accurate modeling and understanding the physics of gas transport phenomena in nanoporous media is still a challenge for researchers and traditional investigation（analytical and experimental methods） have many limitations in studying the generic behavior. In this paper, we used Nano-CT to observe the pore structures of samples of the tight sandstone of western of Sichuan. Combined with advanced image processing technology, threedimensional distributions of the nanometer-sized pores were reconstructed and a tight sandstone digital core model was built, as well the pore structure parameters were analyzed quantitatively. Based on the digital core model, the diffusion process of methane molecules from a higher concentration area to a lower concentration area was simulated by a finite volume method. Finally, the reservoir＇s concentration evolution was visualized and the intrinsic molecular diffusivity tensor which reflects the diffusion capabilities of this rock was calculated. Through comparisons, we found that our calculated result was in good agreement with other empirical results. This study provides a new research method for tight sandstone digital rock physics. It is a foundation for future tight sandstone gas percolation theory and numerical simulation research.展开更多
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 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.
基金supported by Open Fund (PLN1506) of State Key Laboratory of Oil and Gas Reservoir Geology and ExploitationChinese National Natural Science Foundation (41502287)+2 种基金Chongqing Basic and Frontier Research Projects (CSTC2015JCYJBX0120)Chongqing City Social Undertakings and Livelihood Protection Science and Technology Innovation Special Project (CSTC2017SHMSA120001)Chongqing Land Bureau Science and Technology Planning Project (CQGT-KJ-2017026,CQGTKJ-2015044,CQGT-KJ-2015018, CQGT-KJ-2014040)
文摘Diffusion is an important mass transfer mode of tight sandstone gas. Since nano-pores are extensively developed in the interior of tight sandstone, a considerable body of research indicates that the type of diffusion is mainly molecular diffusion based on Fick＇s law. However, accurate modeling and understanding the physics of gas transport phenomena in nanoporous media is still a challenge for researchers and traditional investigation（analytical and experimental methods） have many limitations in studying the generic behavior. In this paper, we used Nano-CT to observe the pore structures of samples of the tight sandstone of western of Sichuan. Combined with advanced image processing technology, threedimensional distributions of the nanometer-sized pores were reconstructed and a tight sandstone digital core model was built, as well the pore structure parameters were analyzed quantitatively. Based on the digital core model, the diffusion process of methane molecules from a higher concentration area to a lower concentration area was simulated by a finite volume method. Finally, the reservoir＇s concentration evolution was visualized and the intrinsic molecular diffusivity tensor which reflects the diffusion capabilities of this rock was calculated. Through comparisons, we found that our calculated result was in good agreement with other empirical results. This study provides a new research method for tight sandstone digital rock physics. It is a foundation for future tight sandstone gas percolation theory and numerical simulation research.
