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Exploring battery material failure mechanisms through synchrotron X-ray characterization techniques 被引量:1
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作者 Lingzhe Fang Xiaozhao Liu Tao Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期128-135,共8页
Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synch... Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synchrotron-based X-ray techniques with high flux and brightness play a key role in understanding degradation mechanisms.In this comprehensive review,we summarize recent advancements in degra-dation modes and mechanisms that were revealed by synchrotron X-ray methodologies.Subsequently,an overview of X-ray absorption spectroscopy and X-ray scattering techniques is introduced for charac-terizing failure phenomena at local coordination atomic environment and long-range order crystal struc-ture scale,respectively.At last,we envision the future of exploring material failure mechanism. 展开更多
关键词 Battery failure Synchrotron-based techniques x-ray scattering x-ray absorption spectroscopy
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Assessing efficacy of standard impregnation techniques on die-cast aluminum alloys using X-ray micro-CT
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作者 Ajith Bandara Koichi Kan +3 位作者 Katanaga Yusuke Natsuto Soga Akifumi Koike Toru Aoki 《China Foundry》 SCIE EI CAS CSCD 2024年第3期276-286,共11页
Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to a... Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to address leakage defects in die-cast Al alloys.In this study,the efficacy of the VPI technique in sealing alloy parts was investigated using a combination of nondestructive micro X-ray computed tomography(micro XCT)and a standard leak test.The results demonstrate that the commonly used water leak test is insufficient for determining the sealing performance.Instead,micro XCT shows distinct advantages by enabling more comprehensive analysis.It reveals the presence of a low atomic number impregnates sealant within casting defects,which has low grey contrast and allows for visualizing primary leakage paths in 3D.The effective atomic number of impregnated resin is 6.75 and that of Al alloy is 13.69 by dual-energy X-ray CT.This research findings will contribute to enhancing the standard VPI process parameters and the properties of impregnating sealants to improve quality assurance for impregnation in industrial metals. 展开更多
关键词 nondestructive testing Al alloy die-casting vacuum pressure impregnation micro x-ray computed tomography duel-energy x-ray CT
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The application of synchrotron X-ray techniques to the study ofrechargeable batteries 被引量:4
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作者 Zhengliang Gong Yong Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2018年第6期1566-1583,共18页
The increased use of rechargeable batteries in portable electronic devices and the continuous develop-ment of novel applications (e.g. transportation and large scale energy storage), have raised a strong de-mand for... The increased use of rechargeable batteries in portable electronic devices and the continuous develop-ment of novel applications (e.g. transportation and large scale energy storage), have raised a strong de-mand for high performance batteries with increased energy density, cycle and calendar life, safety andlower costs. This triggers significant efforts to reveal the fundamental mechanism determining batteryperformance with the use of advanced analytical techniques. However, the inherently complex character-istics of battery systems make the mechanism analysis sophisticated and difficult. Synchrotron radiationis an advanced collimated light source with high intensity and tunable energies. It has particular ad-vantages in electronic structure and geometric structure (both the short-range and long-range structure)analysis of materials on different length and time scales. In the past decades, synchrotron X-ray tech-niques have been widely used to understand the fundamental mechanism and guide the technologicaloptimization of batteries. In particular, in situ and operando techniques with high spatial and temporalresolution, enable the nondestructive, real time dynamic investigation of the electrochemical reaction,and lead to significant deep insights into the battery operation mechanism. This review gives a brief introduction of the application of synchrotron X-ray techniques to the inves-tigation of battery systems. The five widely implicated techniques, including X-ray diffraction (XRD), PairDistribution Function (PDF), Hard and Soft X-ray absorption spectroscopy (XAS) and X-ray photoelectronspectroscopy (XPS) will be reviewed, with the emphasis on their in situ studies of battery systems during cycling. 展开更多
关键词 Rechargeable battery Synchrotron x-ray techniques x-ray diffraction x-ray absorption spectroscopy Pair Distribution Function x-ray photoelectron spectroscopy
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Optimized protocol of multiple post-processing techniques improves diagnostic accuracy of multidetector computed tomography in assessment of small bowel obstruction compared with conventional axial and coronal reformations 被引量:2
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作者 Lian-Qin Kuang Wei Tang +3 位作者 Ran Li Cheng Cheng Shuang-Yue Tang Yi Wang 《World Journal of Gastroenterology》 SCIE CAS 2019年第9期1100-1115,共16页
BACKGROUND Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography(MDCT)examination of patients with small bowel obstruction(SBO) or oth... BACKGROUND Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography(MDCT)examination of patients with small bowel obstruction(SBO) or other abdominal diseases. The diagnostic accuracy of MDCT for assessing SBO is expected to be further improved through the use of multiple post-processing techniques.AIM To systemically evaluate the diagnostic accuracy and efficiency of an optimized protocol using multiple post-processing techniques for MDCT assessment of SBO and secondary bowel ischemia.METHODS This retrospective cross-sectional study included 106 patients with clinically suspected SBO. Two readers applied three protocols to image post-processing and interpretation of patients' MDCT volume data. We compared the three protocols based on time spent, number of images, diagnostic self-confidence,agreement, detection rate, and accuracy of detection of SBO and secondary bowel ischemia.RESULTS Protocol 2 resulted in more time spent and number of images than protocols 1 and 3(P < 0.01), but the results of the two readers using the same protocol were not different(P > 0.05). Using protocol 3, both readers added multiple postprocessing techniques at frequencies of 29.2% and 34.9%, respectively, for obstruction cause, and 32.1% and 30.2%, respectively, for secondary bowel ischemia. Protocols 2 and 3 had higher total detection rates of obstruction cause and secondary bowel ischemia than protocol 1(P < 0.01), but no difference was detected between protocols 2 and 3(P > 0.05). The accuracy, sensitivity,specificity, positive predictive value and negative predictive value of protocols 2 and 3 were superior to those of protocol 1 for evaluating obstruction cause and secondary bowel ischemia.CONCLUSION Our optimized protocol of multiple post-processing techniques can both guarantee efficiency and improve diagnostic accuracy of MDCT for assessing SBO and secondary bowel ischemia. 展开更多
关键词 INTESTINE Intestinal OBSTRUCTION MULTIDETECTOR computed tomography Diagnostic techniqueS and procedures
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Simultaneous fluorescence and Compton scattering computed tomography based on linear polarization X-ray
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作者 Zhi-Jun Chi Hong-Ze Zhang +7 位作者 Jin Lin Xuan-Qi Zhang Hao Ding Qi-Li Tian Zhi Zhang Ying-Chao Du Wen-Hui Huang Chuan-Xiang Tang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第10期41-50,共10页
Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of th... Purpose To propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized X-rays.Methods Monte Carlo simulations were adopted to demonstrate the feasibility of the proposed method.In the simulations,the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum,water,and gold(Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%,and a parallel-hole collimator imaging geometry was adopted.The light source was modeled based on a Thomson scattering X-ray source.The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization algorithm.Results Both the X-ray fluorescence computed tomography(XFCT)and Compton scattering computed tomography(CSCT)images of the phantom were accurately reconstructed.A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images.The interplay between XFCT and CSCT was analyzed,and the contrast-to-noise ratio(CNR)of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities.Compared with K-edge subtraction imaging,XFCT exhibits a CNR advantage for the phantom.Conclusion Simultaneous XFCT and CSCT can be realized by using linearly polarized X-rays.The synergy between the two imaging modalities would have an important application in cancer radiation therapy. 展开更多
关键词 x-ray fluorescence computed tomography Compton scattering computed tomography Linear polarization Thomson scattering x-ray source Monte Carlo simulation
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Passive seismic velocity tomography on longwall mining panel based on simultaneous iterative reconstructive technique (SIRT) 被引量:13
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作者 N.Hosseini K.Oraee +1 位作者 K.Shahriar K.Goshtasbi 《Journal of Central South University》 SCIE EI CAS 2012年第8期2297-2306,共10页
Mining operation, especially underground coal mining, always has the remarkable risks of ground control. Passive seismic velocity tomography based on simultaneous iterative reconstructive technique (SIRT) inversion ... Mining operation, especially underground coal mining, always has the remarkable risks of ground control. Passive seismic velocity tomography based on simultaneous iterative reconstructive technique (SIRT) inversion is used to deduce the stress redistribution around the longwall mining panel. The mining-induced microseismic events were recorded by mounting an array of receivers on the surface, above the active panel. After processing and filtering the seismic data, the three-dimensional tomography images of the p-wave velocity variations by SIRT passive seismic velocity tomography were provided. To display the velocity changes on coal seam level and subsequently to infer the stress redistribution, these three-dimensional tomograms into the coal seam level were sliced. In addition, the boundary element method (BEM) was used to simulate the stress redistribution. The results show that the inferred stresses from the passive seismic tomograms are conformed to numerical models and theoretical concept of the stress redistribution around the longwall panel. In velocity tomograms, the main zones of the stress redistribution arotmd the panel, including front and side abutment pressures, and gob stress are obvious and also the movement of stress zones along the face advancement is evident. Moreover, the effect of the advance rate of the face on the stress redistribution is demonstrated in tomography images. The research result proves that the SIRT passive seismic velocity tomography has an ultimate potential for monitoring the changes of stress redistribution around the longwall mining panel continuously and subsequently to improve safety of mining operations. 展开更多
关键词 longwall mining passive seismic velocity tomography simultaneous iterative reconstructive technique (SIRT) boundary element method stress redistribution ground control
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Screening and early diagnosis of osteoporosis through X-ray and ultrasound based techniques 被引量:5
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作者 Paola Pisani Maria Daniela Renna +5 位作者 Francesco Conversano Ernesto Casciaro Maurizio Muratore Eugenio Quarta Marco Di Paola Sergio Casciaro 《World Journal of Radiology》 CAS 2013年第11期398-410,共13页
Effective prevention and management of osteoporosis would require suitable methods for population screenings and early diagnosis. Current clinicallyavailable diagnostic methods are mainly based on the use of either X-... Effective prevention and management of osteoporosis would require suitable methods for population screenings and early diagnosis. Current clinicallyavailable diagnostic methods are mainly based on the use of either X-rays or ultrasound(US). All X-ray based methods provide a measure of bone mineral density(BMD), but it has been demonstrated that other structural aspects of the bone are important in determining fracture risk, such as mechanical features and elastic properties, which cannot be assessed using densitometric techniques. Among the most commonly used techniques, dual X-ray absorptiometry(DXA) is considered the current 'gold standard' for osteoporosis diagnosis and fracture risk prediction. Unfortunately, as other X-ray based techniques, DXA has specific limitations(e.g., use of ionizing radiation, large size of the equipment, high costs, limited availability) that hinder its application for population screenings and primary care diagnosis. This has resulted in an increasing interest in developing reliable pre-screening tools for osteoporosis such as quantitative ultrasound(QUS) scanners, which do not involve ionizing radiation exposure and represent a cheaper solution exploiting portable and widely available devices. Furthermore, the usefulness of QUS techniques in fracture risk prediction has been proven and, with the last developments, they are also becoming a more and more reliable approach for assessing bone quality. However, the US assessment of osteoporosis is currently used only as a pre-screening tool, requiring a subsequent diagnosis confirmation by means of a DXA evaluation. Here we illustrate the state of art in the early diagnosis of this 'silent disease' and show up recent advances for its prevention and improved management through early diagnosis. 展开更多
关键词 Diagnosis of OSTEOPOROSIS SCREENING techniqueS x-ray BASED methods Quantitative ULTRASOUND Peripheral sites Bone mineral density
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Dynamic phase transition behavior of a LiMn_(0.5)Fe_(0.5)PO_(4) olivine cathode material for lithium-ion batteries revealed through in-situ X-ray techniques 被引量:5
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作者 Sujeera Pleuksachat Phongsit Krabao +6 位作者 Sarawut Pongha Viyada Harnchana Pawinee Klangtakai Wanwisa Limphirat Siriwat Soontaranon Jeffrey Nash Nonglak Meethong 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第8期452-459,I0012,共9页
LiMn_(0.5)Fe_(0.5)PO_(4) has attracted great interest due to its good electrochemical performance and higher operating voltages.This has led to a greater than 30 percent higher energy density than for commercial Li Fe... LiMn_(0.5)Fe_(0.5)PO_(4) has attracted great interest due to its good electrochemical performance and higher operating voltages.This has led to a greater than 30 percent higher energy density than for commercial Li Fe PO4 olivine cathodes.Understanding the phase transition behaviors and kinetics of this material will help researchers to design and develop next generation cathodes for Li-ion batteries.In this study,we investigated non-equilibrium phase transition behaviors in a LiMn_(0.5)Fe_(0.5)PO_(4) cathode material during charge–discharge processes by varying current rates(C-rates)using synchrotron in-situ X-ray techniques.These methods included wide angle X-ray scattering(in-situ WAXS)and X-ray absorption spectroscopy(in-situ XAS).The WAXS spectra indicate that the phase transition of LiMn_(0.5)Fe_(0.5)PO_(4) material at slow C-rates is induced by a two-phase reaction.In contrast,at a high C-rate(5 C),the formation of an intermediate phase upon discharge is clearly observed.Concurrently,the oxidation numbers of the redox reactions of Fe^(2+)/Fe^(3+)and Mn^(2+)/Mn^(3+)were evaluated using in-situ XAS.This combination of synchrotron in-situ X-ray techniques gives clear insights into the non-equilibrium phase transition behavior of a LiMn_(0.5)Fe_(0.5)PO_(4) cathode material.This new understanding will be useful for further developments of this highly promising cathode material for practical commercialization. 展开更多
关键词 LiMn_(0.5)Fe_(0.5)PO_(4) Phase transition In-situ x-ray techniques
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A new stacking technique in ambient noise tomography 被引量:1
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作者 Yongshun John Chen 《Earthquake Science》 CSCD 2010年第6期627-636,共10页
We have developed a new stacking technique in ambient noise tomography to obtain high-quality dispersion curves of Rayleigh waves. This technique is used to stack the vertical components of the Estimated Green Functio... We have developed a new stacking technique in ambient noise tomography to obtain high-quality dispersion curves of Rayleigh waves. This technique is used to stack the vertical components of the Estimated Green Functions (EGFs) obtained respectively from cross correlation of the ambient noise data recorded by a remote seismic station and one of the short distance seismic stations of a seismic array. It is based on a phase-matched filter and is implemented by a four-step iterative process: signal compression, stacking, signal extraction and signal decompression. The iterative process ends and gives the dispersion curve of Rayleigh wave when the predicted one and the processing result converge. We have tested the method using the vertical components of synthetic Rayleigh wave records. Results show that this new stacking method is stable and it can improve the quality of dispersion curves. In addition, we have applied this method to real data. We see that the results given by our new technique are obviously better than the ones employing the traditional method which is a three-step process: signal compression, signal extraction and signal decompression. In conclusion, the new method proposed in this paper can improve the signal to noise ratio of EGFs, and can therefore potentially improve the resolution of ambient noise tomography. 展开更多
关键词 SEISMOTECTONICS continental dynamics ambient noise tomography array technique STACKING
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A machine learning-based strategy for predicting the mechanical strength of coral reef limestone using X-ray computed tomography
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作者 Kai Wu Qingshan Meng +4 位作者 Ruoxin Li Le Luo Qin Ke ChiWang Chenghao Ma 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2790-2800,共11页
Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL... Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL samples were utilized for training the support vector machine(SVM)-,random forest(RF)-,and back propagation neural network(BPNN)-based models,respectively.Simultaneously,the machine learning model was embedded into genetic algorithm(GA)for parameter optimization to effectively predict uniaxial compressive strength(UCS)of CRL.Results indicate that the BPNN model with five hidden layers presents the best training effect in the data set of CRL.The SVM-based model shows a tendency to overfitting in the training set and poor generalization ability in the testing set.The RF-based model is suitable for training CRL samples with large data.Analysis of Pearson correlation coefficient matrix and the percentage increment method of performance metrics shows that the dry density,pore structure,and porosity of CRL are strongly correlated to UCS.However,the P-wave velocity is almost uncorrelated to the UCS,which is significantly distinct from the law for homogenous geomaterials.In addition,the pore tensor proposed in this paper can effectively reflect the pore structure of coral framework limestone(CFL)and coral boulder limestone(CBL),realizing the quantitative characterization of the heterogeneity and anisotropy of pore.The pore tensor provides a feasible idea to establish the relationship between pore structure and mechanical behavior of CRL. 展开更多
关键词 Coral reef limestone(CRL) Machine learning Pore tensor x-ray computed tomography(CT)
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Computed tomography of Crohn's disease:The role of three dimensional technique 被引量:1
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作者 Siva P Raman Karen M Horton Elliot K Fishman 《World Journal of Radiology》 CAS 2013年第5期193-201,共9页
Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive ... Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive evaluation of the small bowel,and has proved to be of significant value in the diagnosis of Crohn's disease.Advancements in CT enterography protocol design,three dimensional(3-D) post-processing software,and CT scanner technology have allowed increasing accuracy in diagnosis,and the acquisition of studies at a much lower radiation dose.The cases in this review will illustrate that the use of 3-D technique,proper enterography protocol design,and a detailed understanding of the different manifestations of Crohn's disease are all critical in properly diagnosing the full range of possible complications in Crohn's patients.In particular,CT enterography has proven to be effective in identifying involvement of the small and large bowel(including active inflammation,stigmata of chronic inflammation,and Crohn's-related bowel neoplasia) by Crohn's disease,as well as the extra-enteric manifestations of the disease,including fistulae,sinus tracts,abscesses,and urologic/hepatobiliary/osseous complications.Moreover,the proper use of 3-D technique(including volume rendering and maximum intensity projection) as a routine component of enterography interpretation can play a vital role in improving diagnostic accuracy. 展开更多
关键词 Crohn’s disease COMPUTED tomography ANGIOGRAPHY MULTIDETECTOR COMPUTED tomography Three dimensional technique Volume rendering Maximum intensity projection FISTULA Dose reduction
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Contribution of Electrical Resistivity Tomography and Boring Technique in the Realization of Ten (10) Large Boreholes in a Crystalline Basement Rocks in the Centre-West of Benin 被引量:1
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作者 Nesny Yanonvoh Akokponhoué Nicaise Yalo +2 位作者 Bertrand Houngnigbo Akokponhoué Rita Houngue George Agbahoungba 《Journal of Geoscience and Environment Protection》 2019年第9期114-130,共17页
In order to ensure access to drinking water for Benin populations by 2021, the Emergency Measure program for the reinforcement of the drinking water supply system of Savalou city was initiated in 2018. This program fo... In order to ensure access to drinking water for Benin populations by 2021, the Emergency Measure program for the reinforcement of the drinking water supply system of Savalou city was initiated in 2018. This program focuses on densification and extension of hydraulic infrastructures. Therefore, it is prominent to use rigorous approach for implementation and execution of drilling activities. The present work has the advantage of combining the use of electrical resistivity tomography and borehole technique to locate ten high flow drilling in Savalou city. The electrical resistivity tomography (ERT) panels were made based on the dipole-dipole arrays with 48 electrodes with 5 m inter-electrode spacing. The drilling was carried out over ten selected points and in two stages: confirmation test using piezometer and borehole diameter enlargement. Moreover, only piezometers with flow rate greater than 10 m3/h were enlarged. The tomography processing has identified 10 fractured zones that are defined by 250 - 1000 ohm.m resistivity values and a width between 15 - 55 m. The confirmation test carried out over ten piezometers exhibits high flow rates ranging from 9 to 35 m3/h with depths of 30 to 68 m. Nine over the ten boreholes with a flow rate equal or greater than 10 m3/h, have improved their flow rates by 50% to 100% after the boring technique. Thus, the cumulative flow rate has reached 252. 7 m3/h for Savalou city and his surrounding areas. 展开更多
关键词 BORING technique Electrical RESISTIVITY tomography FRACTURES Savalou
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Understanding Pseudocapacitance Mechanisms by Synchrotron X-ray Analytical Techniques 被引量:1
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作者 Pei Tang Wuyang Tan +7 位作者 Guangyang Deng Yunting Zhang Shan Xu Qijun Wang Guosheng Li Jian Zhu Qingyun Dou Xingbin Yan 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期312-331,共20页
Pseudocapacitive materials that store charges via reversible surface or near-surface faradaic reactions are capable of overcoming the capacity limitations of electrical double-layer capacitors.Revealing the structure... Pseudocapacitive materials that store charges via reversible surface or near-surface faradaic reactions are capable of overcoming the capacity limitations of electrical double-layer capacitors.Revealing the structure–activity relationship between the microstructural features of pseudocapacitive materials and their electrochemical performance on the atomic scale is the key to build high-performance capacitor-type devices containing ideal pseudocapacitance effect.Currently,the high brightness(flux),and spectral and coherent nature of synchrotron X-ray analytical techniques make it a powerful tool for probing the structure–property relationship of pseudocapacitive materials.Herein,we report a comprehensive and systematic review of four typical characterization techniques(synchrotron X-ray diffraction,pair distribution function[PDF]analysis,soft X-ray absorption spectroscopy,and hard X-ray absorption spectroscopy)for the study of pseudocapacitance mechanisms.In addition,we offered significant insights for understanding and identifying pseudocapacitance mechanisms(surface redox pseudocapacitance,intercalation pseudocapacitance,and the extrinsic pseudocapacitance phenomenon in battery materials)by combining in situ hard XAS and electrochemical analyses.Finally,a perspective for further depth of understanding into the pseudocapacitance mechanism using synchrotron X-ray analytical techniques is proposed. 展开更多
关键词 in situ experiments pseudocapacitive materials structure-property relationship synchrotron x-ray analytical techniques
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New tomographic reconstruction technique based on Laplacian eigenfunction
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作者 Yasuhiro SUZUKI Shishir PUROHIT +2 位作者 Satoshi OHDACHI Satoshi YAMAMOTO Kazunobu NAGASAKI 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第10期5-9,共5页
This letter proposes a new tomographic reconstruction procedure based on the Laplacian eigenfunction(LEF) patterns, which are independent of the plasma cross-section and do not require the flux surface information. Th... This letter proposes a new tomographic reconstruction procedure based on the Laplacian eigenfunction(LEF) patterns, which are independent of the plasma cross-section and do not require the flux surface information. The process is benchmarked for the experimental data of Heliotron J plasma and the results are compared with the least-squares approximation by a Phillips–Tikhonov(PT)-type regularization, which is widely used as the standard technique for tomographic reconstruction. The reconstruction based on the LEF is found to be capable of determining the magnetic axis at different time locations efficiently in comparison with the PT-type regularization. 展开更多
关键词 tomography Laplacian eigenfunction Heliotron J soft x-ray
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Ultrasmall CoS nanoparticles embedded in heteroatom-doped carbon for sodium-ion batteries and mechanism explorations via synchrotron X-ray techniques
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作者 Congcong Liu Qiongqiong Lu +8 位作者 Mikhail V.Gorbunov Ahmad Omar Ignacio G.Gonzalez Martinez Panpan Zhao Martin Hantusch Antonius Dimas Chandra Permana Huanyu He Nikolai Gaponik Daria Mikhailova 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期373-381,共9页
Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity... Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity fade and low rate capability.In this work,a composite containing ultrasmall CoS(~7 nm)nanoparticles embedded in heteroatom(N,S,and O)-doped carbon was synthesized by an efficient one-step sulfidation process using a Co(Salen)precursor.The ultrasmall CoS nanoparticles are beneficial for mechanical stability and shortening Na-ions diffusion pathways.Furthermore,the N,S,and O-doped defect-rich carbon provides a robust and highly conductive framework enriched with active sites for sodium storage as well as mitigates volume expansion and polysulfide shuttle.As anode for SIB,CoS@HDC exhibits a high initial capacity of 906 mA h g^(-1)at 100 mA g^(-1)and a stable long-term cycling life with over 1000 cycles at 500 mA g^(-1),showing a reversible capacity of 330 mA h g^(-1).Meanwhile,the CoS@HDC anode is proven to maintain its structural integrity and compositional reversibility during cycling.Furthermore,Na-ion full batteries based on the CoS@HDC anode and Na_(3)V_(2)(PO_(4))_(3)cathode demonstrate a stable cycling behavior with a reversible specific capacity of~200 m A h g^(-1)at least for 100 cycles.Moreover,advanced synchrotron operando X-ray diffraction,ex-situ X-ray absorption spectroscopy,and comprehensive electrochemical tests reveal the structural transformation and the Co coordination chemistry evolution of the CoS@HDC during cycling,providing fundamental insights into the sodium storage mechanism. 展开更多
关键词 Sodium-ion batteries Cobalt sulfide nanoparticles Heteroatom-doped porous carbon matrix Synchrotron x-ray techniques Reaction mechanisms
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Computed Tomography Using a Low Tube Voltage Technique for Acute Ischemic Stroke
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作者 Kenji Nakamura Katsuhiko Maeda +3 位作者 Masao Tanooka Shuhei Aoyama Reiichi Ishikura Noriko Kotoura 《Advances in Computed Tomography》 2019年第2期24-35,共12页
Computed tomography (CT) is commonly used to assess for cerebral hemorrhage and acute ischemic stroke. We investigated the accuracy of CT using a low tube voltage technique in acute ischemic stroke. We compared the st... Computed tomography (CT) is commonly used to assess for cerebral hemorrhage and acute ischemic stroke. We investigated the accuracy of CT using a low tube voltage technique in acute ischemic stroke. We compared the standard deviation (SD), contrast between gray and white matter, and contrast-to-noise ratio (CNR) between three groups (120 kV 500 mAs, 100 kV 850 mAs, and 100 kV 750 mAs using hybrid iterative reconstruction) in 50 patients without lesions, and visual evaluation using the normalized rank approach was also performed. The mean value of SD was 4.02, 4.22, and 4.04, respectively, and the contrast between gray and white matter was 7.08, 8.66, and 8.68 HU, respectively;in addition, the CNR was 1.77, 2.06, and 2.15, respectively. The difference between the 100 kV and 120 kV groups was significant (p 0.01). Visual evaluation showed a significant difference between the 100 and 120 kV groups (p 0.05). 展开更多
关键词 LOW Tube Voltage technique COMPUTED tomography Acute ISCHEMIC STROKE
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Effects of combining multiple dose reduction techniques on coronary computed tomography angiography
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作者 Xiao-Lu Hu Pei-Kai Huang +2 位作者 Meng Zhang Jun Chen Meng-Qiang Xiao 《World Journal of Radiology》 2023年第2期32-41,共10页
BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awar... BACKGROUND Coronary computed tomography angiography(CCTA)is the preferred noninvasive examination method for coronary heart disease.However,the radiation from computed tomography has become a concern since public awareness of radiation hazards continue to increase.AIM To explore the value of multiple dose reduction techniques for CCTA.METHODS Consecutive normal and overweight patients were prospectively divided into two groups:Group A1,patients who received multiple dose reduction scans(n=82);and group A2,patients who received conventional scans(n=39).The scan parameters for group A1 were as follows:Isocentric scan,tube voltage=80 kV,and tube current control using 80%smart milliampere.The scan parameters for group A2 were as follows:Normal position,tube voltage=100 kV,and smart milliampere.RESULTS The average effective doses(EDs)for groups A1 and A2 were 1.13±0.35 and 3.36±1.30 mSv,respectively.There was a statistically significant difference in ED between the two groups(P<0.01).Furthermore,noise was significantly lower,and both signal-to-noise ratio and contrast signal-to-noise ratio were higher in group A2 when compared to group A1(P<0.01).Moreover,the subjective image quality(IQ)scores were excellent in both groups,in which there was no significant difference in subjective IQ score between the two groups(P=0.12).CONCLUSION Multiple dose reduction scan techniques can significantly decrease the ED of patients receiving CCTA examinations for clinical diagnosis. 展开更多
关键词 Isocentric scanning Coronary heart disease Dose reduction techniques Coronary computed tomography angiography RADIATION
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Multi-slice three-dimensional spiral CT cholangiography: a new technique for diagnosis of biliary diseases 被引量:22
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作者 Ai-Min Xu Hong-Yan Cheng +3 位作者 Wen-Bin Jiang Dong Chen Yu-Chen Jia Meng-Chao Wu the Department of Radiology, Eastern Hepatobiliary Surgery Hospital, Shanghai 200438, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2002年第4期595-603,共9页
Objective: To validate multi-slice three-dimensional spiral CT cholangiography (3-D CTC) in clinical di- agnosis of biliary diseases. Methods: This study included 146 patients with bili- ary diseases, involving 73 cas... Objective: To validate multi-slice three-dimensional spiral CT cholangiography (3-D CTC) in clinical di- agnosis of biliary diseases. Methods: This study included 146 patients with bili- ary diseases, involving 73 cases of biliary tumor, 87 cases of radioparent calculus, 12 cases of post cholan- gio-jejunostomy and one case of congenital choledo- chocyst. The data of thin-slice volumetric CT scan were sent to the workstation (GE Advantage Win- dows 3. 1). Rational 3-D CTC including maximum intensity projection, minimum intensity projection, surface shaded display, CT virtual endoscopy and ray sumption was performed. The diagnostic accura- cy of 3-D CTC was compared with that of conven- tional CT, ultrasonography and endoscopic retro- grade cholangiopancreaticography (ERCP). Results: Different biliary diseases showed distinct ima- ging manifestations on 3-D CTC, As a new technique for assessing the status of post cholangio-jejunosto- my, 3-D CTC was superior to conventional CT, ul- trasonography and ERCP in diagnosis of negative bil- iary calculus, extrahepatic cholangiocarcinoma, cancer embolus of the biliary duct, carcinoma of the pancreas head and periampullar carcinoma. It was also superior to conventional CT, ultrasonography or equal to ERCP in diagnosis of hilar cholangiocarcino- ma, but inferior to conventional CT and ultrasonog- raphy in diagnosis of gallbladder cancer. Conclusion: 3-D CTC as a non-invasive and sensitive technique for the diagnosis of biliary diseases with high diagnostic accuracy will greatly increase the de- tection rate of biliary diseases. 展开更多
关键词 x-ray computed tomography CHOLANGIOGRAPHY bile duct
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Use of X-ray computed tomography to study structures and particle contacts of granite residual soil 被引量:14
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作者 SUN Yin-lei TANG Lian-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第4期938-954,共17页
A small problem about soil particle regularization and contacts but essential to geotechnical engineering was studied.The soils sourced from Guangzhou and Xiamen were sieved into five different particle scale ranges(d... A small problem about soil particle regularization and contacts but essential to geotechnical engineering was studied.The soils sourced from Guangzhou and Xiamen were sieved into five different particle scale ranges(d<0.075 mm,0.075 mm≤d<0.1 mm,0.1 mm≤d<0.2 mm,0.2 mm≤d<0.5 mm and 0.5 mm≤d<1.0 mm)to study the structures and particle contacts of granite residual soil.The X-ray micro computed tomography method was used to reconstruct the microstructure of granite residual soil.The particle was identified and regularized using principal component analysis(PCA).The particle contacts and geometrical characteristics in 3D space were analyzed and summarized using statistical analyses.The results demonstrate that the main types of contact among the particles are face-face,face-angle,face-edge,edge-edge,edge-angle and angle-angle contacts for particle sizes less than 0.2 mm.When the particle sizes are greater than 0.2 mm,the contacts are effectively summarized as face-face,face-angle,face-edge,edge-edge,edge-angle,angle-angle,sphere-sphere,sphere-face,sphere-edge and sphere-angle contacts.The differences in porosity among the original sample,reconstructed sample and regularized sample are closely related to the water-swelling and water-disintegrable characteristics of granite residual soil. 展开更多
关键词 x-ray computed tomography granite residual soil RECONSTRUCTION REGULARIZATION particle contact
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Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles 被引量:8
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作者 Bao-hua Yang Ai-xiang Wu +2 位作者 Guillermo A.Narsilio Xiu-xiu Miao Shu-yue Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第9期965-973,共9页
Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle,... Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle, a cylindrical copper oxide ore sample (I center dot 4.6 mm x 5.6 mm) was scanned using high-resolution X-ray computed tomography (HRXCT), a nondestructive imaging technology, at a spatial resolution of 4.85 mu m. Combined with three-dimensional (3D) image analysis techniques, the main mineral phases and pore space were segmented and the volume fraction of each phase was calculated. In addition, the mass fraction of each mineral phase was estimated and the result was validated with that obtained using traditional techniques. Furthermore, the pore phase features, including the pore size distribution, pore surface area, pore fractal dimension, pore centerline, and the pore connectivity, were investigated quantitatively. The pore space analysis results indicate that the pore size distribution closely fits a log-normal distribution and that the pore space morphology is complicated, with a large surface area and low connectivity. This study demonstrates that the combination of HRXCT and 3D image analysis is an effective tool for acquiring 3D mineralogical and pore structural data. 展开更多
关键词 high-resolution x-ray computed tomography 3D image analysis ore particles mineral dissemination pore space
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