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Calibration Curve Establishment and Fractionation Temperature Selection of Polyethylene for Preparative Temperature Rising Elution Fractionation 被引量:2
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作者 Yan-hu Xue Shu-qin Bo 姬相玲 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2015年第7期1000-1008,共9页
A series of copolymers of ethylene with 1-hexene synthesized using a metallocene catalyst are selected and mixed. The blend is fractionated via preparative temperature rising elution fractionation(P-TREF). All fract... A series of copolymers of ethylene with 1-hexene synthesized using a metallocene catalyst are selected and mixed. The blend is fractionated via preparative temperature rising elution fractionation(P-TREF). All fractions are characterized via high-temperature gel permeation chromatography(GPC), 13 C nuclear magnetic resonance spectroscopy(13C-NMR), and differential scanning calorimetry(DSC). The changes in the DSC melting peak temperatures of the fractions from P-TREF as a function of elution temperature are almost linear, thereby providing a reference through which the elution temperature of TREF experiments could be selected. Moreover, the standard calibration curve(ethylene/1-hexene) of P-TREF is established, which relates to the degree of short-chain branching of the fractions. The standard calibration curve of P-TREF is beneficial to study on the complicated branching structure of polyethylene. A convenient method for selecting the fractionation temperature for TREF experiments is elaborated. The polyethylene sample is fractionated via successive self-nucleation and annealing(SSA) thermal fractionation. A multiple-melting endotherm is obtained through the final DSC heating scan for the sample after SSA thermal fractionation. A series of fractionation temperatures are then selected through the relationship between the DSC melting peak temperature and TREF elution temperature. 展开更多
关键词 TREF calibration curve Fractionation temperature SSA Polyethylene
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Abductive statistical methods improve the results of calibration curve bioassays:An example of determining zinc bioavailability in broiler chickens
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作者 Gene M.Pesti Lynne Billard +3 位作者 Shu-Biao Wu Robert A.Swick Thi Thanh Hoai Nguyen Natalie Morgan 《Animal Nutrition》 SCIE CSCD 2022年第3期294-304,共11页
In this paper,we discuss the theory behind calibration curve experiments and their application to a zinc(Zn)bioavailability study with broiler chickens.Seven replicates of 16 male commercial broiler chicks were fed st... In this paper,we discuss the theory behind calibration curve experiments and their application to a zinc(Zn)bioavailability study with broiler chickens.Seven replicates of 16 male commercial broiler chicks were fed starter diets for 14 days.Six diets had different levels of a potential Zn source and one was a positive control with standard industry levels of Zn for comparison.Four commonly used methods of calculating bioavailability means and confidence intervals(CI)from a calibration curve(standard curve)experiment to estimate the bioavailability of a new zinc source in broiler chickens were compared.The methods compared were the following:1)the Counter-Intuitive Method uses a multiple-range test to compare unknown test and standard samples;2)the Intuitive Method uses standard linear regression and inverts the equation to predict Zn bioavailability for each replicate of test samples;3)the Abductive Method uses Graybill's Equation,based on theory and observation,to estimate CI's;and 4)the Sophistic Method uses reverse regression,and calculates Zn bioavailability values directly from the equation.The Counter-Intuitive Method only gives information about which standards the test samples are,or are not,significantly different from respectively(average available Zn not predicted).The Intuitive Method ignores error about the standard curve and theoretically cannot estimate the CI directly(X±SEM=107.5±15.8 mg Zn/kg).The Sophistic Method underestimates and overestimates the test sample mean values above and below the mean of the standards,respectively(X=96.6 mg Zn/kg).The Abductive Method has an advantage over the other methods:The mean prediction estimation is consistent with theory(107.5±6.1 mg Zn/kg;X±SEM).When test or“unknown”samples are near the mean of the standard samples,the CI is smaller than when near the extremes of the calibration curve.When calibration curve error is small(R^(2)>approximately 0.95),there is little advantage to using the Abductive Method,but when calibration curve error is larger,as in many bioassays with growing animals,the Abductive Method improves the accuracy of the CI calculations.The Abductive Method was used to demonstrate the influence of the number of replicate samples on experimental power and cost. 展开更多
关键词 calibration curve Standard curve Confidence interval BIOAVAILABILITY
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Matrix effect suppressing in the element analysis of soils by laser-induced breakdown spectroscopy with acoustic correction
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作者 何智权 刘莉 +6 位作者 郝中骐 徐智帅 王奇 卢颖 赵梓屹 史久林 何兴道 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第12期97-104,共8页
Laser-induced breakdown spectroscopy(LIBS)has been used for soil analysis,but its measurement accuracy is often influenced by matrix effects of different kinds of soils.In this work,a method for matrix effect suppress... Laser-induced breakdown spectroscopy(LIBS)has been used for soil analysis,but its measurement accuracy is often influenced by matrix effects of different kinds of soils.In this work,a method for matrix effect suppressing was developed using laser-induced plasma acoustic signals to correct the original spectrum,thereby improving the analysis accuracy of the soil elements.A good linear relationship was investigated firstly between the original spectral intensity and the acoustic signals.The relative standard deviations(RSDs)of Mg,Ca,Sr,and Ba elements were then calculated for both the original spectrum and the spectrum with the acoustic correction,and the RSDs were significantly reduced with the acoustic correction.Finally,calibration curves of MgⅠ285.213 nm,CaⅠ422.673 nm,SrⅠ460.733 nm and BaⅡ455.403 nm were established to assess the analytical performance of the proposed acoustic correction method.The values of the determination coefficient(R~2)of the calibration curves for Mg,Ca,Sr,and Ba elements,corrected by the acoustic amplitude,are improved from 0.9845,0.9588,0.6165,and 0.6490 to 0.9876,0.9677,0.8768,and 0.8209,respectively.The values of R~2 of the calibration curves corrected by the acoustic energy are further improved to 0.9917,0.9827,0.8835,and 0.8694,respectively.These results suggest that the matrix effect of LIBS on soils can be clearly improved by using acoustic correction,and acoustic energy correction works more efficiently than acoustic amplitude correction.This work provides a simple and efficient method for correcting matrix effects in the element analysis of soils by acoustic signals. 展开更多
关键词 laser-induced breakdown spectroscopy acoustic correction matrix effect calibration curve relative standard deviation
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Determination of Aluminum in Nickel-Based Superalloys by Using Laser-Induced Breakdown Spectroscopy 被引量:1
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作者 朱德华 王茜 +2 位作者 倪晓武 陈建平 陆建 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第4期486-489,共4页
Laser-induced breakdown spectroscopy (LIBS) was developed to detect aluminum in nickel-based superalloys (K417, GH4033, DZ125L, З ∏742y) using a non-intensified, non-gated, low-cost detection system. The precisi... Laser-induced breakdown spectroscopy (LIBS) was developed to detect aluminum in nickel-based superalloys (K417, GH4033, DZ125L, З ∏742y) using a non-intensified, non-gated, low-cost detection system. The precision of LIBS depends strongly on the experimental conditions. The calibration curves of Al(I)394.4 nm and Al(I)396.2 nm under the optimum experimental parameters are presented. Finally the limit of detection (LOD) for aluminum is calculated from the experimental data, which is in the range of 0.09% to 0.1% by weight. 展开更多
关键词 aluminum emission lines LIBS nickel based superalloys calibration curve limit of detection
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Effects of CT based Voxel Phantoms on Dose Distribution Calculated with Monte Carlo Method 被引量:1
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作者 陈朝斌 黄群英 吴宜灿 《Plasma Science and Technology》 SCIE EI CAS CSCD 2005年第2期2777-2780,共4页
A few CT-based voxel phantoms were produced to investigate the sensitivity of Monte Carlo simulations of X-ray beam and electron beam to the proportions of elements and the mass densities of the materials used to expr... A few CT-based voxel phantoms were produced to investigate the sensitivity of Monte Carlo simulations of X-ray beam and electron beam to the proportions of elements and the mass densities of the materials used to express the patient’s anatomical structure. The human body can be well outlined by air, lung, adipose, muscle, soft bone and hard bone to calculate the dose distribution with Monte Carlo method. The effects of the calibration curves established by using various CT scanners are not clinically significant based on our investigation. The deviation from the values of cumulative dose volume histogram derived from CT-based voxel phantoms is less than 1% for the given target. 展开更多
关键词 CT voxel phantom calibration curve Monte Carlo dose calculation
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Closed/Open-Cell Photoacoustic Imaging for Spectroscopic Measurements 被引量:1
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作者 Tsutomu Hoshimiya 《Journal of Applied Mathematics and Physics》 2016年第8期1470-1474,共6页
Photoacoustic imaging using a closed photoacoustic cell and an open photoacoustic cell with gas- microphone detection scheme was described. R/G/B LED light sources were used for the closed photoacoustic (PA) cell conf... Photoacoustic imaging using a closed photoacoustic cell and an open photoacoustic cell with gas- microphone detection scheme was described. R/G/B LED light sources were used for the closed photoacoustic (PA) cell configuration. The colored specimen enclosed in a PA cell was imaged with R/G/B color light sources, and an image restored from the inverted PA images was compared with the original image. For open cell configuration, an open PA cell using a spheroidal acoustic resonator was applied to measure the amount of large-sized colored specimens. A calibration curve for a food red dye was obtained that apparently showed the ability of the present scheme to measure as a spectroscopic measurement tool. 展开更多
关键词 PHOTOACOUSTIC IMAGING SPECTROSCOPIC calibration curve Color Restoration
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Excitation curve calibration for the SSRF magnet system
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作者 周雪梅 刘桂民 +2 位作者 后接 张文志 田顺强 《Chinese Physics C》 SCIE CAS CSCD 2010年第5期589-592,共4页
The needed electrical current for the magnet working under different energy loads can be easily calculated once the right relation between the magnet and the electrical current has been found. Therefore the excitation... The needed electrical current for the magnet working under different energy loads can be easily calculated once the right relation between the magnet and the electrical current has been found. Therefore the excitation curve calibration for the magnet system is important to the SSRF. The measuring method on the magnet and the result of the excitation curve calibration are presented. The application of the excitation curve calibration for the bending magnet is given, and it is proved that the COD (Closed Orbit Distortion) and the working point of the storage ring are greatly affected by the current of the bending magnet. 展开更多
关键词 SSRF storage ring excitation curve calibration
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Variation of the friction conditions in cold ring compression tests of medium carbon steel 被引量:6
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作者 Dawei ZHANG Bingkun LIU +2 位作者 Jingxiang LI Minchao CUI Shengdun ZHAO 《Friction》 SCIE CSCD 2020年第2期311-322,共12页
Lubrication and friction conditions vary with deformation during metal forming processes.Significant macro-variations can be observed when a threshold of deformation is reached.This study shows that during the cold co... Lubrication and friction conditions vary with deformation during metal forming processes.Significant macro-variations can be observed when a threshold of deformation is reached.This study shows that during the cold compression processing of#45(AISI 1045)steel rings,the magnitude of friction and surface roughness(Ra)changes significantly upon reaching a 45%reduction in ring height.For example,the Ra of compressed ring specimens increased by approximately 55%immediately before and after reaching this threshold,compared to an 18% or 25%variation over a 35%-45%or a 45%-55%reduction in height,respectively.The ring compression test conducted by this study indicates that the Coulomb friction coefficient and Tresca friction factor mare 0.105 and 0.22,respectively,when the reduction in height is less than 45%;and 0.11 and 0.24,respectively,when the reduction in height is greater than 45%. 展开更多
关键词 friction condition ring compression test friction calibration curve surface topography
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Experimental measurement of the correlation between CT number and heavy ion range 被引量:2
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作者 贺鹏博 李强 +2 位作者 刘新国 叶飞 戴中颖 《Chinese Physics C》 SCIE CAS CSCD 2012年第10期954-957,共4页
For precision delivery of the Bragg peak of a heavy-ion beam to a target volume in ion beam therapy, it is necessary to know the tissue stopping power. A general approach to solve this problem in ion beam therapy is t... For precision delivery of the Bragg peak of a heavy-ion beam to a target volume in ion beam therapy, it is necessary to know the tissue stopping power. A general approach to solve this problem in ion beam therapy is to convert X-ray CT (computed tomography) numbers into water-equivalent path length (WEPL) coefficients using a CT-WEPL calibration curve for all voxels traversed by the beam. This work aims at establishing a CT-WEPL coefficient calibration curve for the heavy ion therapy project at IMP, so as to compute the range of carbon ion beams in tissues easily according to the patient CT data. Several tissueequivalent materials were applied to measure their WEPL coefficients using a high-energy carbon ion beam in this work. A CT-WEPL calibration curve was obtained through fitting the measured data, which can be used directly for dose optimization and facilitates the design of patient treatment plans significantly at IMP. 展开更多
关键词 heavy ion therapy CT number WEPL CT-WEPL calibration curve
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A general strategy to quantify analytes through fluorescence chromaticity and luminosity
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作者 Tianyu Liang Peiwei Yang +4 位作者 Tianhong Wu Menghan Shi Xiayu Xu Taotao Qiang Xiaolong Sun 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第11期2975-2979,共5页
To realize a fast,easy-operation and precise way using fluorescence probes to quantify analytes is a goal to facilitate detection,especially in situ.Herein,we are reporting an approach which can be generally employed ... To realize a fast,easy-operation and precise way using fluorescence probes to quantify analytes is a goal to facilitate detection,especially in situ.Herein,we are reporting an approach which can be generally employed for the differentiation and quantitation of analytes through fluorescence chromaticity and luminosity.Seven representative fluorescent probes,targeting p H,cysteine,hydrogen sulfide,hydrogen peroxide,palladium and hydrazine,were synthesized and tested.Without utilizing costly instrumentations,portable devices were employed to collect data of photographs from the fluorescence samples in responses to different analytes.Subsequently,the photographic images were digitally processed to generate calibration curves between chromaticity/luminosity verse concentrations after mapping to the CIE 1931 xy Y standard color space.Good linear calibration curves and quantitative analysis of unknown samples with low errors through the spectral technology demonstrated the reliability of this method.Thus,we showed the analytical method with a simple and on-site constructible/portable device which is promising for applications in more fluorescence probes. 展开更多
关键词 Fluorescence probes Portable device calibration curve PHOTOGRAPHY Chromaticity and luminosity
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In situ Analysis of Na and K in a Laminar Premixed Flame by Laser-induced Breakdown Spectroscopy
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作者 LI Yu ZHANG Han-zhuang +3 位作者 LI Zhong-shan LI Hong-dong ZHANG Chun-wei HU Chang-hong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2013年第6期1149-1152,共4页
Laser-induced breakdown spectroscopy(LIBS) was used to in situ monitor the concentration of alkali elements in combustion environments. Particular efforts were made to optimize the temporally resolved spectra of Na ... Laser-induced breakdown spectroscopy(LIBS) was used to in situ monitor the concentration of alkali elements in combustion environments. Particular efforts were made to optimize the temporally resolved spectra of Na and K elements. Calibration curves were constructed by relating the intensities of the specific lines to the corres- ponding elemental concentrations. The detection limits of Na and K elements were found to be temperature- dependent. The results indicate that LIBS can be a powerful tool for in situ monitoring Na and K concentrations in combustion environments. 展开更多
关键词 Laser-induced breakdown spectroscopy(LIBS) Alkali metal Solution-seeded calibration curve
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