The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is det...The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is determined by a newly optimized Voigt function in present investigation. Furthermore, for Cu-4 wt pet Ti alloy aged at 400℃ for 720 min and 1080 min, after introducing the weight factor of above two satellites intensity, the relative error between the fitting curves and X-ray diffraction profiles is less than 0.185%, which is more precise than the previously calculating result.展开更多
The microfibril angle of fiber walls is an ultra-mieroscopic feature affecting the performance of wood products. It is therefore essential to get more definitive information to improve selection and utilization. X-ray...The microfibril angle of fiber walls is an ultra-mieroscopic feature affecting the performance of wood products. It is therefore essential to get more definitive information to improve selection and utilization. X-ray diffraction is a rapid method for measuring microfibril angles. In this paper, the variability of microfibril angle in plantation-grown Masson pine was investigated by peak-fitting method. This method was compared with the traditional hand-drawn method, 40% peak height method and half peak height method. X-ray diffraction measurements indicated that the microfibril angle changed as a function of the position in the tree. The mean microfibril angle decreased more gradually as the distance increased from the pith and reached the same level in mature wood. The microfibril angle also seemed to decrease clearly from the base upward. Differences of angle-intensity curves between heartwood and sapwood were also examined.展开更多
[Objective] The aim of this study was to provide a basis for distinguishing quality of rhubarb in different production areas. [Method ] X-ray diffraction patterns of rhubarbs in different production areas of Qinghai w...[Objective] The aim of this study was to provide a basis for distinguishing quality of rhubarb in different production areas. [Method ] X-ray diffraction patterns of rhubarbs in different production areas of Qinghai were obtained by X-ray diffraction analysis, and then its similarity analysis was also investigated. [ Result] The content of chemical components in rhubarbs from different production areas had differences, but its diffraction patterns and diffraction peaks had certain fingerprint characteristics. [ Conclusion] X-ray diffraction method is a fast and effective method for identifying rhubarb and other Chinese herbal medicines in different production areas.展开更多
A set of absorption curves was priorly prepared on transparent films to fit the background and peak intensities in continuous scanning X-ray stress measurement.It may be better to correct both background and absorptio...A set of absorption curves was priorly prepared on transparent films to fit the background and peak intensities in continuous scanning X-ray stress measurement.It may be better to correct both background and absorption of pure diffraction intensity.Experimental results revealed this to be a reliable correction method.展开更多
X-ray diffraction (XRD) peaks in a low-angle diffraction section of clayminerals, especially those of authigenic origin, have broadening and tailing features in shape.Using the five basic parameters, peak position, pe...X-ray diffraction (XRD) peaks in a low-angle diffraction section of clayminerals, especially those of authigenic origin, have broadening and tailing features in shape.Using the five basic parameters, peak position, peak height, width, shape coefficient and asymmetry,to describe an XRD peak is more accurate, comprehensive and integrated than using only 3 of them,position, height and width. Following the concept of the five basic parameters of an XRD peak, theprogram Decoform proposed in this study provides more information in mineralogical analyses byfitting actual XRD profiles. In combination with the HW-IR plot, Decoform can he systematically andaccurately used in the comprehensive analyses of crystallinity, domain size, lattice strain andquantitative phase. It is also of value for the geological investigations of diagenesis,metamorphism, basin maturity, structural stress field and so on.展开更多
According to feasibility of Gaussian peaks decomposing distribution function (DF) 4πrρ(r), radial distribution function (RDF) 4πr 2ρ(r) of simple liquids also is possibly decomposed into Gaussian peaks withr in th...According to feasibility of Gaussian peaks decomposing distribution function (DF) 4πrρ(r), radial distribution function (RDF) 4πr 2ρ(r) of simple liquids also is possibly decomposed into Gaussian peaks withr in the size of several atoms. Experimental structure parameters of pure liquid Al and Si were obtained by θ-θ X-ray diffraction measurements and following data processing. Based on Gaussian decomposing liquid aluminum’s DF 4πrρ(r), liquid aluminum and silicon’s radial distribution function (RDF) 4πr 2ρ(r), it is shown that RDF of simple liquids is able to be decomposed in Gaussian function, compared with decomposing of DF, supplying more physical meaning and better indicating the short range order of liquids, which draws a clearer structure picture of simple liquids.展开更多
基金supported by the Aeronautical Basic Science Foundation(No.00G53054)the National Natural Science Foundation of China(No.50171053).
文摘The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is determined by a newly optimized Voigt function in present investigation. Furthermore, for Cu-4 wt pet Ti alloy aged at 400℃ for 720 min and 1080 min, after introducing the weight factor of above two satellites intensity, the relative error between the fitting curves and X-ray diffraction profiles is less than 0.185%, which is more precise than the previously calculating result.
基金This study was financially supported by the National Natural Science Foundation of China （Grant Nos. 30371125 and 30400337）.
文摘The microfibril angle of fiber walls is an ultra-mieroscopic feature affecting the performance of wood products. It is therefore essential to get more definitive information to improve selection and utilization. X-ray diffraction is a rapid method for measuring microfibril angles. In this paper, the variability of microfibril angle in plantation-grown Masson pine was investigated by peak-fitting method. This method was compared with the traditional hand-drawn method, 40% peak height method and half peak height method. X-ray diffraction measurements indicated that the microfibril angle changed as a function of the position in the tree. The mean microfibril angle decreased more gradually as the distance increased from the pith and reached the same level in mature wood. The microfibril angle also seemed to decrease clearly from the base upward. Differences of angle-intensity curves between heartwood and sapwood were also examined.
文摘[Objective] The aim of this study was to provide a basis for distinguishing quality of rhubarb in different production areas. [Method ] X-ray diffraction patterns of rhubarbs in different production areas of Qinghai were obtained by X-ray diffraction analysis, and then its similarity analysis was also investigated. [ Result] The content of chemical components in rhubarbs from different production areas had differences, but its diffraction patterns and diffraction peaks had certain fingerprint characteristics. [ Conclusion] X-ray diffraction method is a fast and effective method for identifying rhubarb and other Chinese herbal medicines in different production areas.
文摘A set of absorption curves was priorly prepared on transparent films to fit the background and peak intensities in continuous scanning X-ray stress measurement.It may be better to correct both background and absorption of pure diffraction intensity.Experimental results revealed this to be a reliable correction method.
基金the National Natural Science Foundation of China (Grant No.49872033) the special pre-research project of the Basic Scientific Program.the Ministry of Science and Technology of China (Grant No. 2001CCA02400).
文摘X-ray diffraction (XRD) peaks in a low-angle diffraction section of clayminerals, especially those of authigenic origin, have broadening and tailing features in shape.Using the five basic parameters, peak position, peak height, width, shape coefficient and asymmetry,to describe an XRD peak is more accurate, comprehensive and integrated than using only 3 of them,position, height and width. Following the concept of the five basic parameters of an XRD peak, theprogram Decoform proposed in this study provides more information in mineralogical analyses byfitting actual XRD profiles. In combination with the HW-IR plot, Decoform can he systematically andaccurately used in the comprehensive analyses of crystallinity, domain size, lattice strain andquantitative phase. It is also of value for the geological investigations of diagenesis,metamorphism, basin maturity, structural stress field and so on.
基金Project supported by the National Natural Science Foundation of China (Grant No. 59671046).
文摘According to feasibility of Gaussian peaks decomposing distribution function (DF) 4πrρ(r), radial distribution function (RDF) 4πr 2ρ(r) of simple liquids also is possibly decomposed into Gaussian peaks withr in the size of several atoms. Experimental structure parameters of pure liquid Al and Si were obtained by θ-θ X-ray diffraction measurements and following data processing. Based on Gaussian decomposing liquid aluminum’s DF 4πrρ(r), liquid aluminum and silicon’s radial distribution function (RDF) 4πr 2ρ(r), it is shown that RDF of simple liquids is able to be decomposed in Gaussian function, compared with decomposing of DF, supplying more physical meaning and better indicating the short range order of liquids, which draws a clearer structure picture of simple liquids.
