期刊文献+
共找到82篇文章
< 1 2 5 >
每页显示 20 50 100
Time-resolved ultra-small-angle X-ray scattering beamline(BL10U1)at SSRF
1
作者 Wen-Qiang Hua Chun-Ming Yang +12 位作者 Ping Zhou Feng Tian Jin-You Lin Yu-Zhu Wang Xiao-Yun Li Xia-Ran Miao Chun-Xia Hong Qiu-Shi Huang Xin-Tong Zhao Yong-Feng Men Jie Wang Xing-Yu Gao Xiu-Hong Li 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期6-19,共14页
The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X... The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results. 展开更多
关键词 synchrotron radiation Ultra-small-angle x-ray scattering Micro small-angle x-ray scattering USAXS Time resolved μSAXS
下载PDF
Small-angle X-ray scattering investigation of aging behavior of Al-Cu-Mg-Ag alloys using synchrotron radiation 被引量:3
2
作者 Zhang Jianbo Zhang Yongan +3 位作者 Zhu Baohong Liu Ruiqing Li Zhihui Li Xiwu 《Rare Metals》 SCIE EI CAS CSCD 2012年第6期537-540,共4页
The aging behavior of Al-Cu-Mg-Ag alloys with high Cu/Mg was studied by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) using synchrotron radiation. TEM study reveals that the major stre... The aging behavior of Al-Cu-Mg-Ag alloys with high Cu/Mg was studied by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) using synchrotron radiation. TEM study reveals that the major strengthening phases of the alloy after aging at 160?C for 10 h are Ω and less θ′. SAXS study shows that the scattering patterns are composed of several concentric circles at the beginning of aging process, which is replaced by the butterfly-wings scattering patterns with the increase of aging time. The butterfly-wings scattering patterns are composed of several branches. The angles between the branches are roughly equal to that between the habit planes of precipitates. The evolution of Guinier radius with aging time indicates the good coarsening resistance of the precipitates. The evolution of integrated intensity is consistent with the classical two-step precipitation process. 展开更多
关键词 Al-Cu-Mg-Ag alloys precipitate size synchrotron radiation small angle x-ray scattering
下载PDF
Investigation of the topological shape of bovine serum albumin in solution by small-angle x-ray scattering at Beijing synchrotron radiation facility
3
作者 董淑强 李丽琴 +2 位作者 刘鹏 董宇辉 陈熙萌 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第12期4574-4579,共6页
This paper reports that at a newly constructed small-angle x-ray scattering station of Beijing Synchrotron Radia- tion Facility, the topological shape of ligand-free bovine serum albumin in solution has been investiga... This paper reports that at a newly constructed small-angle x-ray scattering station of Beijing Synchrotron Radia- tion Facility, the topological shape of ligand-free bovine serum albumin in solution has been investigated. An appropriate scattering curve is obtained and the calculated value of the gyration radius is 31.2~=t=0.25 ~_ (11=0.1 nm) which is co- incident with other ones' results. It finds that the low-resolution structure models obtained by making use of ab initio reconstruction methods are fitting the crystal structure of human serum albumin very well. All of these results perform the potential of the beamline to apply to structural biology studies. The characteristics, the defects, and the improving measures of the station in future are also discussed. 展开更多
关键词 small-angle x-ray scattering ab initio methods bovine serum albumin Beijing synchrotron radiation facility
下载PDF
The Significance of Solutions Obtained from Ill-Posed Systems of Linear Equations Constituted by Synchrotron Radiation Based Anomalous Small-Angle X-Ray Scattering
4
作者 Günter Johannes Goerigk 《Advances in Linear Algebra & Matrix Theory》 2018年第1期64-86,共23页
Synchrotron radiation based experimental techniques known as Anomalous Small-Angle X-ray Scattering (ASAXS) provide deep insight into the nanostructure of uncountable material systems in condensed matter research i.e.... Synchrotron radiation based experimental techniques known as Anomalous Small-Angle X-ray Scattering (ASAXS) provide deep insight into the nanostructure of uncountable material systems in condensed matter research i.e. solid state physics, chemistry, engineering and life sciences thereby rendering the origin of the macroscopic functionalization of the various materials via correlation to its structural architecture on a nanometer length scale. The techniques constitute a system of linear equations, which can be treated by matrix theory. The study aims to analyze the significance of the solutions of the stated matrix equations by use of the so-called condition numbers first introduced by A. Turing, J. von Neumann and H. Goldstine. Special attention was given for the comparison with direct methods i.e. the Gaussian elimination method. The mathematical roots of ill-posed ASAXS equations preventing matrix inversion have been identified. In the framework of the theory of von Neumann and Goldstine the inversion of certain matrices constituted by ASAXS gradually becomes impossible caused by non-definiteness. In Turing’s theory which starts from more general prerequisites, the principal minors of the same matrices approach singularity thereby imposing large errors on inversion. In conclusion both theories recommend for extremely ill-posed ASAXS problems avoiding inversion and the use of direct methods for instance Gaussian elimination. 展开更多
关键词 Matrix Inversion Condition NUMBERS LU-Decomposition Gaussian Elimination synchrotron radiation ANOMALOUS small-angle x-ray scattering
下载PDF
Real-time pore structure evolution difference between deep and shallow coal during gas adsorption:A study based on synchrotron radiation small-angle X-ray scattering
5
作者 Yingfeng Sun Shuaipeng Zhu +3 位作者 Fei Xie Chujian Han Yixin Zhao Zetian Zhang 《Particuology》 SCIE EI CAS CSCD 2024年第4期114-123,共10页
Coal seam CO_(2) sequestration is an important option to address global warming.A better knowledge on coal pore structure evolution during gas adsorption can provide guidance for coal seams CO_(2) seques-tration.Howev... Coal seam CO_(2) sequestration is an important option to address global warming.A better knowledge on coal pore structure evolution during gas adsorption can provide guidance for coal seams CO_(2) seques-tration.However,few investigations on the pore structure evolution differences between the deep and shallow coal were conducted during gas adsorption.In this study,based on the real-time synchrotron radiation small-angle X-ray scattering(SAXS)observation,the average pore diameter and pore surface fractal dimension evolution differences between deep and shallow coal were investigated from the as-pects of coal compositions and stress history.Two types of coal deformation(inner-swelling and outer-swelling)coexist during gas adsorption.Coal compositions have significant impact on the dominance of deformation type.The dominance of inner-swelling in deep coal is induced by the higher ash contents,and there is the decrease of average pore diameter during gas adsorption.The impact of stress-history(burial depth)on adsorption-induced deformation is more prominent than that of gas adsorption ca-pacity.In deep coal,the surface fractal dimension evolution presents a negative correlation with the evolution of pore diameters.In shallow coal,the surface fractal dimension evolution presents a Langmuir-type correlation with the adsorption time. 展开更多
关键词 COAL Gas adsorption synchrotron radiation small-angle x-ray scattering Pore diameter Surface fractal dimension
原文传递
BL19U2:Small-angle X-ray scattering beamline for biological macromolecules in solution at SSRF 被引量:5
6
作者 Yi-Wen Li Guang-Feng Liu +4 位作者 Hong-Jin Wu Ping Zhou Chun-Xia Hong Na Li Feng-Gang Bian 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2020年第12期32-40,共9页
The BL19U2 at the Shanghai Synchrotron Radiation Facility is a small-angle X-ray scattering beamline dedicated to structural studies pertaining to biological macromolecules in solution.The beamline has been officially... The BL19U2 at the Shanghai Synchrotron Radiation Facility is a small-angle X-ray scattering beamline dedicated to structural studies pertaining to biological macromolecules in solution.The beamline has been officially opened to users in March 2015,and since then,a series of technological innovations has been developed to optimize beamline performance,thereby significantly improving the data collection efficiency and broadening the application scope of biological small-angle X-ray scattering.BL19U2 is ideal for the high-throughput screening of weakly scattered proteins,protein assemblies,nucleic acids,inorganic nanomaterials,and organic drug molecules.This paper describes the design and overview of the BL19U2 beamline.Versatile sample environments at the experimental station and some recent scientific highlights are presented. 展开更多
关键词 Shanghai synchrotron radiation facility Biological small-angle x-ray scattering High-throughput screening Biological macromolecules
下载PDF
Small Angle X-ray Scattering Study of Precipitation Kinetics in Al-Zn-Mg-Cu Alloys 被引量:3
7
作者 Zhiwei DU Tietao ZHOU +3 位作者 Peiying LIU Huanxi LI Baozhong DONG Changqi CHEN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第4期479-483,共5页
The evolution of microstructure parameters (precipitate size and volume fraction) for two types of Al-Zn-Mg-Cu alloys (7075 and 7055) during aging has been studied by synchrotron-radiation small angle X-ray scatte... The evolution of microstructure parameters (precipitate size and volume fraction) for two types of Al-Zn-Mg-Cu alloys (7075 and 7055) during aging has been studied by synchrotron-radiation small angle X-ray scattering (SAXS).The results show that the precipitates are only a few nanorneters for both alloys ageing even at higher temperature of 160℃ for 72 h (4.44 and 5.82 nm, respectively). The maximum of the precipitate volume fraction increases with in creasing Zn content and is about 0.023-0.028 and 0.052-0.054, respectively. The coarsening of precipitate is consistent with LSW (Lifshitz-Slyozov-Wagner) model even at the initial stage where volume fraction is still varying.The activation energy of coarsening regime has been determined to be about 1.22±0.02 eV and 1.25±0.02 eV for alloys 7075 and 7055, respectively. 展开更多
关键词 small angle x-ray scattering (SAXS) AI-Zn-Mg-Cu alloys Ageing Precipitate size Volume fraction
下载PDF
Growth Kinetics of Nanocrystals and Nanorods by Employing Small-angle X-ray Scattering (SAXS) and Other Techniques 被引量:2
8
作者 Kanishka BISWAS Neenu VARGHESE C.N.R.Rao 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第4期615-627,共13页
In this article, we report the results of our detailed investigations of the growth kinetics of zero-dimensional nanocrystals as well as one-dimensional nanorods by the combined use of small angel X-ray scattering (S... In this article, we report the results of our detailed investigations of the growth kinetics of zero-dimensional nanocrystals as well as one-dimensional nanorods by the combined use of small angel X-ray scattering (SAXS), transmission electron microscopy (TEM) along with other physical techniques. The study includes growth kinetics of gold nanocrystals formed by the reduction of HAuCl4 by tetrakis(hydroxymethyl) phosphonium chloride in aqueous solution, of CdSe nanocrystals formed by the reaction of cadmium stearate and selenium under solvothermal conditions, and of ZnO nanorods formed by the reaction of zinc acetate with sodium hydroxide under solvothermal conditions in the absence and presence of capping agents. The growth of gold nanocrystals does not follow the diffusion-limited Ostwald ripening, and instead follows a Sigmoidal rate curve. The heat change associated with the growth determined by isothermal titration calorimetry is about 10 kcal·mol^-1 per I nm increase in the diameter of the nanocrystals. In the case of CdSe nanocrystals also, the growth mechanism deviates from diffusion-limited growth and follows a combined model containing both diffusion and surface reaction terms. Our study of the growth kinetics of uncapped and poly(vinyl pyrollidone) (PVP)-capped ZnO nanorods has yielded interesting insights. We observe small nanocrystals next to the ZnO nanorods after a lapse of time in addition to periodic focusing and defocusing of the width of the length distribution. These observations lend support to the diffusion-limited growth model for the growth of uncapped ZnO nanorods. Accordingly, the time dependence on the length of uncapped nanorods follows the L3 law as required for diffusion-limited Ostwald ripening. The PVP-capped nanorods, however, show a time dependence, which is best described by a combination of diffusion (L^3) and surface reaction (L^2) terms. 展开更多
关键词 Growth kinetics Gold nanocrystals CdSe nanocrystals ZnO nanorods small angle x-ray scattering Transmission electron microscopy Ostwald ripening and sigmoidal growth
下载PDF
Small Angle X-ray Scattering Study of PS Conformation in Tetrahydrofuran Solvent with Gas Anti-solvent 被引量:1
9
作者 Dan LI Zhi Min LIU +5 位作者 Guan Ying YANG Qing HUO Bu Xing HAN Yi LIU Zhong Hua WU Bao Zhong DONG 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第12期1093-1094,共2页
Small angle X-ray scattering (SAXS) was used to study the effect of dissolved CO2 on the conformation of polystyrene (PS) in PS/tetrahydrofuran(THF) solution at 308.15 K and at pressures up to 3 MPa. The cloud pressur... Small angle X-ray scattering (SAXS) was used to study the effect of dissolved CO2 on the conformation of polystyrene (PS) in PS/tetrahydrofuran(THF) solution at 308.15 K and at pressures up to 3 MPa. The cloud pressure and the expansion curve of the solution were also determined. The dependence of the conformation on pressure was discussed. 展开更多
关键词 small angle x-ray scattering POLYSTYRENE THF CO2 CONFORMATION
下载PDF
Scanning Microfocus Small Angle X-ray Scattering Study of the Avian Eggshell
10
作者 D. Lammie M. M. Bain +1 位作者 S. E. Solomon T. J. Wess 《Journal of Bionic Engineering》 SCIE EI CSCD 2006年第1期11-18,共8页
Synchrotron microfocus small angle X-ray scattering was used to investigate the nanostructure and microscopic variation of eggshells. It uses a microbeam allowing the ability to probe interactions between the organic ... Synchrotron microfocus small angle X-ray scattering was used to investigate the nanostructure and microscopic variation of eggshells. It uses a microbeam allowing the ability to probe interactions between the organic and inorganic components at nanometer level and is ideal for mapping over small areas to obtain a detailed analysis of structural variations. Thin sections of eggshells were scanned from the shell membrane (inner) to the cuticle (outer) surface. The data collected was used to produce two-dimensional maps showing microscopic changes within the different layers of the eggshell. The structural alterations ap- parently could have implications at the macroscopic level of the resulting eggshell. As the organic matrix is embedded within the eggshell this may contribute to the variations observed in calcite crystal form and texture, Structural information obtained about a biomaterial at different length scales is important in relating the structure to its functional properties. This knowledge and the principles behind the formation of biomaterials could be used in the attempt of bioengineering new systems. 展开更多
关键词 biomaterial EGGSHELL NANOSTRUCTURE microfocus small angle x-ray scattering
下载PDF
Characteristics of AOT Microemulsion Structure: a Small Angle X-ray Scattering Study
11
作者 Jun Cheng LIU Gan Zuo LI Bu Xing HAN 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第11期1023-1026,共2页
The method of synchrotron radiation small-angle X-ray scattering (SR-SAXS) has been used to obtain structural information on the system of bis (2-ethylhexyl) sulfosuccinate (AOT)/H2O/isooctane. By using the Guinier pl... The method of synchrotron radiation small-angle X-ray scattering (SR-SAXS) has been used to obtain structural information on the system of bis (2-ethylhexyl) sulfosuccinate (AOT)/H2O/isooctane. By using the Guinier plot (Ln I (q) versus q(2)) on the data sets in a defined small q range (0.03-0.06 Angstrom (-1)), the gyration radius at different water/surfactant molar ratio, W-0, was obtained. With the increase of W-0, the gyration radius (R-g) increased at the range of 23.2 similar to 52.7 Angstrom. 展开更多
关键词 bis(2-ethylhexyl)suffosuccinate(AOT) MICROEMULSION gyration radius small angle x-ray scattering
下载PDF
Probing Nanoscale Morphology of PS/PMMA/CdS &PS/PVC/CdS Polymeric Nanocomposites through Small Angle X-Ray Scattering Analysis
12
作者 Vishal Mathur Kananbala Sharma 《Modern Instrumentation》 2014年第4期25-28,共4页
Polymeric nanocomposites of PS/PMMA/CdS and PS/PVC/CdS samples have been synthesized through dispersion solution casting technique. The nanoparrticles of CdS were prepared by simple chemical method using CdCl2 and H2S... Polymeric nanocomposites of PS/PMMA/CdS and PS/PVC/CdS samples have been synthesized through dispersion solution casting technique. The nanoparrticles of CdS were prepared by simple chemical method using CdCl2 and H2S gas produced from thiourea. The nanoscale morphology of the prepared polymeric nanocomposite samples is probed through small angle X-ray scattering (SAXS). The SAXS study reveals that CdS nanoparticles take place at voids position in the respective plymer blend matrix and exhibit their nano nature with very little tendency to agglomerates. 展开更多
关键词 small angle x-ray scattering POLYMER NANOCOMPOSITE CDS Nanoparticles POLYMER Characterization
下载PDF
Stability of the Dividing Distribution Function Method for ParticleSize Distribution Analysis in Small Angle X-Ray Scattering 被引量:2
13
作者 Zhang Jinyuan Liu Chunlan Chen Yan 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 1996年第1期51-52,63+54-55,共5页
The Dividing Distribution Function (DDF) method is one of the methods by which the particle size distribution of ultrafine powder can be evaluated from its small angle X-ray scattering data. In this paper, the stabili... The Dividing Distribution Function (DDF) method is one of the methods by which the particle size distribution of ultrafine powder can be evaluated from its small angle X-ray scattering data. In this paper, the stability of the solution obtained from DDF method has been investigated through optimizing the coefficient matrix, introducing a damping factor and a least square treatment. All calculations were accomplished with a microcomputer. It was shown that the average deviations of the size distribution obtained are not larger than the assigned random errors to the scattering intensities as long as the corresponding requirements are satisfied. 展开更多
关键词 ultrafine powder particle size distribution small angle x-ray scattering dividing distribution function method
下载PDF
Nano-scale pore distribution characterisation of coal using small angle X-ray scattering
14
作者 Peng Jia Jinzhang Jia Sadegh Nadimi 《Particuology》 SCIE EI CAS CSCD 2023年第10期73-85,共13页
In the process of coal seam fracturing with liquid nitrogen(LN_(2)),the change of coal pore structure has an important influence on the efficiency of coalbed methane(CBM)extraction.The nano-scale pore size distributio... In the process of coal seam fracturing with liquid nitrogen(LN_(2)),the change of coal pore structure has an important influence on the efficiency of coalbed methane(CBM)extraction.The nano-scale pore size distribution(PSD)in coal particles before and after freezing with LN_(2) are experimentally studied in this work.Coal samples are collected from four coal mines,where coal and gas outburst accidents have occurred.Small angle X-ray scattering technology(SAXS)and scanning electron microscopy(SEM)are used to study the pore structure changes of coal samples quantitatively and qualitatively.It is found that the scattering intensity of coal samples increases after freezing.The PSD of all samples significantly changes in the range of 0.8–7 nm,showing new pore spaces in 0.8–4 nm and fewer pores in the 4–7 nm range.Both the pore fractal dimension and the radius of gyration of coal samples increase after freezing and are mainly affected by the changes in pores and the anisotropy of the coal matrix.Crack expansion and pore connections are observed in the surface structure of the coal sample using SEM.This study provides a better understanding of the nano-scale mechanism of coal seam fracturing with LN_(2) for the prevention of coal and gas outbursts. 展开更多
关键词 Coalbed methane small angle x-ray scattering LN2 freezing Pore size distribution(PSD) Particle characterisation Fractal dimension
原文传递
Small angle X-ray scattering of the colloidal crystal 被引量:1
15
作者 蓝鼎 王育人 +2 位作者 张荫民 王维 吴忠华 《Chinese Physics C》 SCIE CAS CSCD 2009年第11期1016-1018,共3页
The monodisperse polystyrene spheres are assembled into the colloidal crystal on the glass substrate by vertical deposition method, which is aimed at the so-called photonic crystal applications. The structural informa... The monodisperse polystyrene spheres are assembled into the colloidal crystal on the glass substrate by vertical deposition method, which is aimed at the so-called photonic crystal applications. The structural information of the bulk colloidal crystal is crucial for understanding the crystal growth mechanism and devel- oping the various applications of colloidal crystal. Small-angle X-ray scattering (SAXS) technique was used to obtain the bulk structure of the colloidal crystal at Beamline lW2A of BSRF. It is found that the SAXS pattern is sensitive to the relative orientation between the colloidal sample and the incident X-ray direction. The crystal lattice was well distinguished and determined by the SAXS data. 展开更多
关键词 colloidal crystal small angle x-ray scattering photonic crystal
原文传递
DETERMINATION OF SIZE DISTRIBUTION OF THE CRYSTALLINE PARTICLE IN AGED METALLIC GLASS BY SMALL ANGLE X-RAY SCATTERING
16
作者 孟昭富 《Chinese Science Bulletin》 SCIE EI CAS 1992年第11期958-961,共4页
Ⅰ. INTRODUCTIONAlthough many authors have investigated the structure of annealed metallic glass by means of small angle X-ray scattering (SAXS), there has been no report in which size distribution of the crystalline ... Ⅰ. INTRODUCTIONAlthough many authors have investigated the structure of annealed metallic glass by means of small angle X-ray scattering (SAXS), there has been no report in which size distribution of the crystalline particle in aged metallic glass is determined. Determining size distribution of the crystalline particle will be beneficial to understanding the nucleation and growth process of the crystalline particle. In this note, size distribution of the crystalline parti- 展开更多
关键词 small angle x-ray scattering METALLIC glass size distribution of the CRYSTALLINE PARTICLE
原文传递
DETERMINATION OF THE SHAPE AND DIMENSION OF PRECIPITATE FROM AGED Lc4 ALUMINIUM ALLOY BY SMALL ANGLE X-RAY SCATTERING
17
作者 孟昭富 《Chinese Science Bulletin》 SCIE EI CAS 1989年第17期1489-1493,共5页
Small angle X-ray scattering (SAXS) is extensively used for determining the dimension of a particle, but rarely used for determining its shape. The difficulty is that it needs to do extensive calculations. In addition... Small angle X-ray scattering (SAXS) is extensively used for determining the dimension of a particle, but rarely used for determining its shape. The difficulty is that it needs to do extensive calculations. In addition, it can only be carried out for the mono-dispersion system. In re cent years, Reuther et al. succeeded in determining the shape and dimension of the particle of a polymer gel. 展开更多
关键词 small angle x-ray scattering aluminium alloy SHAPE of PARTICLE DIMENSION of PARTICLE
原文传递
Characterization of the nanopore structures of PAN-based carbon fiber precursors by small angle X-ray scattering
18
作者 王德红 郝俊杰 +4 位作者 邢雪青 默广 宫宇 吕春祥 吴忠华 《Chinese Physics C》 SCIE CAS CSCD 2011年第9期870-874,共5页
The nanopore structures in precursors Four carbon-fiber precursors are prepared. They are crucial to the performance of PAN-based carbon fibers are bath-fed filaments (A), water-washing filaments (B) hot-stretchin... The nanopore structures in precursors Four carbon-fiber precursors are prepared. They are crucial to the performance of PAN-based carbon fibers are bath-fed filaments (A), water-washing filaments (B) hot-stretching filaments (C) and drying-densification filaments (D). Synchrotron radiation small angle X-ray scattering is used to probe and compare the nanopore structures of the four fibers. The nanopore size, discrete volume distribution, nanopore orientation degree along the fiber axis and the porosity are obtained. The results demonstrate that the nanopores are mainly formed in the water-washing stage. During the processes of the subsequent production technologies, the slenderness ratio of nanopores and their orientation degree along the fiber axis increase further and simultaneously, the porosity decreases. These results are helpful for improving the performance of the final carbon fibers. 展开更多
关键词 PAN-based carbon fiber precursor small angle x-ray scattering nanopore structure POROSITY
原文传递
Radiation Damage of Crystal Polyesters
19
作者 ZHANG Yi-qu, JI Dan-liang, LI Zhi-zhong, CHEN Xin-fang and TANG Ao-qing (Institute of Material Science, Jilin University, Changchun, 130023)LUO Yun-xia, Yang Hong and JIANG Bing-zheng (Changchun Institute of Applied Chemistry, Changchun, 130023) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1993年第1期70-73,共4页
The change of crystal structures in polyethylene terephthalate (PET) and polyhexa methylene terephthalate (PHT) irradiated by γ-ray were investigated by using the methods of WAXD and SAXS. It was found that irradiati... The change of crystal structures in polyethylene terephthalate (PET) and polyhexa methylene terephthalate (PHT) irradiated by γ-ray were investigated by using the methods of WAXD and SAXS. It was found that irradiation caused the crystal parameters of PET and PHT to lengthen, and the cell to expand; and at the same time, the long period and the thickness of lamellae were unchanged. These results indicate that the radiation damage of crystal polyesters causes the increase of lacunaries within the crystal polyester. 展开更多
关键词 radiation effect Polyester wide angle small angle x-ray scattering
下载PDF
Influence of energy bandwidth of pink beam on small angle X-ray scattering
20
作者 Shanfeng Wang Yaxiang Liang +4 位作者 Bingjie Wang Weiwei Dong Lingfei Hu Qun Ouyang Peng Liu 《Radiation Detection Technology and Methods》 CSCD 2019年第1期19-26,共8页
Background Compared with the traditional monochromatic synchrotron radiation beam,a pink beam is a quasimonochromatic beam which can be obtained by screening a harmonic of the undulator.The energy bandwidth(E/E)of a ... Background Compared with the traditional monochromatic synchrotron radiation beam,a pink beam is a quasimonochromatic beam which can be obtained by screening a harmonic of the undulator.The energy bandwidth(E/E)of a pink beam is about 10−2.Despite the intensity gain from the quasi-monochromatic beam,the decrease in the energy resolution will lead the collected data to be smeared.Purpose To study the influence of the energy bandwidth on the small angle X-ray scattering(SAXS)by experiments and verify the feasibility of SAXS with a pink beam.Method Firstly,the influence of different energy bandwidths on SAXS has been studied by simulation and experiment.Then,TEM tests have been performed and compared with the experimental results.Result It has been shown that the scattering curves deviate slightly from the traditional monochromatic ones.This deviation does not influence the data processing for the maximum deviation of the results is just less than 2%.In return,the gain in the intensity(one to two orders of magnitude)makes the pink beam very important for the time-resolved SAXS.Further,the results of TEM and SAXS have shown an excellent agreement.Conclusion Thiswork proves that the pink beam could be used for SAXS directly without a desmearing procedure.Benefiting from the increase in the beam intensity,the exposure time can be greatly shortened,thus enhancing the utilization efficiency of the synchrotron radiation. 展开更多
关键词 small angle x-ray scattering(SAXS) Pink beam Adjustable energy bandwidth Smeared effect
原文传递
上一页 1 2 5 下一页 到第
使用帮助 返回顶部