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Improved EEMD-based standardization method for developing long tree-ring chronologies 被引量:4
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作者 Xianliang Zhang Junxia Li +1 位作者 Xiaobo Liu Zhenju Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第6期2217-2224,共8页
Long tree-ring chronologies can be developed by overlapping data from living trees with data from fossil trees through cross-dating.However,low-frequency climate signals are lost when standardizing tree-ring series du... Long tree-ring chronologies can be developed by overlapping data from living trees with data from fossil trees through cross-dating.However,low-frequency climate signals are lost when standardizing tree-ring series due to the"segment length curse".To alleviate the segment length curse and thus improve the standardization method for developing long tree-ring chronologies,here we first calculated a mean value for all the tree ring series by overlapping all of the tree ring series.The growth trend of the mean tree ring width(i.e.,cumulated average growth trend of all the series)was determined using ensemble empirical mode decomposition.Then the chronology was developed by dividing the mean value by the growth trend of the mean value.Our improved method alleviated the problem of trend distortion.Long-term signals were better preserved using the improved method than in previous detrending methods.The chronologies developed using the improved method were better correlated with climate than those developed using conservative methods.The improved standardization method alleviates trend distortion and retains more of the low-frequency climate signals. 展开更多
关键词 standardization methods Tree rings Segment length curse DETRENDING
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MULTI-PARAMETER ACCELERATED MODIFIED NEWTON-RAPHSON METHODS FOR RIGIDPLASTIC FE ANALYSIS
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作者 Shi Gang Liu Xiaolin 《Acta Mechanica Solida Sinica》 SCIE EI 2002年第4期323-331,共9页
Applications of certain multi-parameter acceleration techniques used with themodified New-ton-Raphson (mN-R) methods to solve the nonlinear equations arising from rigid-plasticfinite element analysis are investigated.... Applications of certain multi-parameter acceleration techniques used with themodified New-ton-Raphson (mN-R) methods to solve the nonlinear equations arising from rigid-plasticfinite element analysis are investigated. New modified multi-parameter techniques, developed fromCrisfield's multi-parameter methods, are utilized to solve these nonlinear equations. The numericalperformance of these techniques is compared with the standard Newton-Raphson method (sN-R),Crisfield's single parameter method (C1), Crisfield's two parameter method (C2) and Crisfield'sthree parameter method (C3). The new techniques do not involve additional residual force calculationand require little extra computational effort. In addition, they are more robust and efficient thanother existing acceleration techniques. 展开更多
关键词 rigid-plastic FEM standard newton-raphson method modified newton-raphsonmethod crisfield's multi-parameter accelerated techniques modified multi-parameter acceleratedtechniques
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Application and Development Trends of Spectral Analysis in Draft of Non-Ferrous Metal Standards in China
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作者 Lijun Kuai Huachang Li +1 位作者 Jiemin Liu Shufang Tang 《American Journal of Analytical Chemistry》 2023年第6期239-273,共35页
Spectral analysis was a method of identifying substances, determining their chemical composition and calculating their content based on their spectral characteristics. This paper mainly discussed the application of va... Spectral analysis was a method of identifying substances, determining their chemical composition and calculating their content based on their spectral characteristics. This paper mainly discussed the application of various spectroscopic techniques, mainly including atomic absorption spectrometry (AAS) inductively coupled plasma emission spectrometry (ICP-AES) X-ray fluorescence spectroscopy (XRF) atomic fluorescence spectroscopy (AFS) direct reading spectroscopy (OES) glow discharge emission spectroscopy (GD-OSE) laser-induced breakdown spectroscopy (LIBS), in the formulation of non-ferrous metal standards in China. The AAS method was the most widely used single-element microanalysis method among the non-ferrous metal standards. The ICP-AES method was good at significant advantages in the simultaneous detection of multiple elements. The XRF method was increasingly used in the determination of primary and secondary trace elements due to its simple sample preparation and high efficiency. The AFS was mostly detected by single-element trace analysis. OES GD-OES and LIBS were playing an increasingly important role in the new demand area for non-ferrous metals. This paper discussed matrix elimination, sample digestion, sample preparation, instrument categories and other aspects of some standards, and summarized the advantages of spectral analysis and traditional chemical analysis methods. The new methods of future spectroscopic technology had been illustrated in the process of developing non-ferrous metal standards. 展开更多
关键词 Atomic Absorption Spectroscopy Inductively Coupled Plasma Emission Spectroscopy X-Ray Fluorescence Spectroscopy Atomic Fluorescence Spectroscopy Direct Reading Spectroscopy Glow Discharge Emission Spectroscopy Laser-Induced Breakdown Spectroscopy Non-Ferrous Metals Standard methods Were Formulated
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Quantification of trace amounts of impurities in high purity cobalt by high resolution inductively coupled plasma mass spectrometry 被引量:10
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作者 XIE Hualin HUANG Kelong +1 位作者 NIE Xidu TANG Yougen 《Rare Metals》 SCIE EI CAS CSCD 2007年第3期286-291,共6页
A An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, ... A An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb) in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results. 展开更多
关键词 high resolution inductively coupled plasma mass spectrometry high purity cobalt trace impurities matrix effect standard addition method
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Smart Society and Artificial Intelligence:Big Data Scheduling and the Global Standard Method Applied to Smart Maintenance 被引量:1
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作者 Ruben Foresti Stefano Rossi +2 位作者 Matteo Magnani Corrado Guarino Lo Bianco Nicola Delmonte 《Engineering》 SCIE EI 2020年第7期835-846,共12页
The implementation of artificial intelligence(AI)in a smart society,in which the analysis of human habits is mandatory,requires automated data scheduling and analysis using smart applications,a smart infrastructure,sm... The implementation of artificial intelligence(AI)in a smart society,in which the analysis of human habits is mandatory,requires automated data scheduling and analysis using smart applications,a smart infrastructure,smart systems,and a smart network.In this context,which is characterized by a large gap between training and operative processes,a dedicated method is required to manage and extract the massive amount of data and the related information mining.The method presented in this work aims to reduce this gap with near-zero-failure advanced diagnostics(AD)for smart management,which is exploitable in any context of Society 5.0,thus reducing the risk factors at all management levels and ensuring quality and sustainability.We have also developed innovative applications for a humancentered management system to support scheduling in the maintenance of operative processes,for reducing training costs,for improving production yield,and for creating a human–machine cyberspace for smart infrastructure design.The results obtained in 12 international companies demonstrate a possible global standardization of operative processes,leading to the design of a near-zero-failure intelligent system that is able to learn and upgrade itself.Our new method provides guidance for selecting the new generation of intelligent manufacturing and smart systems in order to optimize human–machine interactions,with the related smart maintenance and education. 展开更多
关键词 Smart maintenance Smart society Artificial intelligence Human-centered management system Big data scheduling Global standard method Society 5.0 Industry 4.0
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Determination of total sulfur in geothermal water by inductively coupled plasma-atomic emission spectrometry 被引量:1
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作者 Bing-bing Liu Mei Han +3 位作者 Jia Liu Na Jia Chen-ling Zhang Lin Zhang 《Journal of Groundwater Science and Engineering》 2022年第3期285-291,共7页
Sulfur speciation and concentration in geothermal water are of great significance for the research and utilization of the water resources.In most situations,it is necessary to determine the total sulfur in geothermal ... Sulfur speciation and concentration in geothermal water are of great significance for the research and utilization of the water resources.In most situations,it is necessary to determine the total sulfur in geothermal water.In this study,the method was established for the determination of determining total sulfur content-the inductively coupled plasma-atomic emission spectrometry(ICP-AES),with the wavelength of 182.034 nm selected in spectral line of sulfur.It was identified that the optimal working conditions of the ICP-AES instrument were 1200 W for high frequency generator power 9 mm for vertical observation height,0.30 MPa atomizer pressure,and 50 r/min analytical pump speed.The matrix interference of the method was eliminated by the matrix matching method.Using this method,sulfur detection limit and minimum quantitative detection limit were 0.028 mg/L and 0.110 mg/L,respectively,whilst the linear range was 0.0-100.0 mg/L.The recovery rate of sample was between 90.67%and 108.7%,and the relative standard deviation(RSD)was between 0.36%and 2.14%.The method was used to analyze the actual samples and the results were basically consistent with the industry standard method.With high analysis efficiency,the method has low detection limit and minimum quantitative detection limit,wide linear range,good precision and accuracy,and provides an important detection method for the determination of total sulfur in geothermal water. 展开更多
关键词 High frequency generator power Vertical observation height Atomizer pressure Matrix matching method Standard addition method
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Analysis of normal human retinal vascular network architecture using multifractal geometry 被引量:1
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作者 Stefan Talu Sebastian Stach +2 位作者 Dan Mihai Calugaru Carmen Alina Lupascu Simona Delia Nicoara 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第3期434-438,共5页
AIM:To apply the multifractal analysis method as a quantitative approach to a comprehensive description of the microvascular network architecture of the normal human retina.METHODS:Fifty volunteers were enrolled in ... AIM:To apply the multifractal analysis method as a quantitative approach to a comprehensive description of the microvascular network architecture of the normal human retina.METHODS:Fifty volunteers were enrolled in this study in the Ophthalmological Clinic of Cluj-Napoca,Romania,between January 2012 and January 2014. A set of 100 segmented and skeletonised human retinal images,corresponding to normal states of the retina were studied. An automatic unsupervised method for retinal vessel segmentation was applied before multifractal analysis. The multifractal analysis of digital retinal images was made with computer algorithms,applying the standard boxcounting method. Statistical analyses were performed using the Graph Pad In Stat software.RESULTS:The architecture of normal human retinal microvascular network was able to be described using the multifractal geometry. The average of generalized dimensions(D_q)for q=0,1,2,the width of the multifractal spectrum(Δα=α_(max)-α_(min))and the spectrum arms' heights difference(│Δf│)of the normal images were expressed as mean±standard deviation(SD):for segmented versions,D_0=1.7014±0.0057; D_1=1.6507±0.0058; D_2=1.5772±0.0059; Δα=0.92441±0.0085; │Δf│= 0.1453±0.0051; for skeletonised versions,D_0=1.6303±0.0051; D_1=1.6012±0.0059; D_2=1.5531± 0.0058; Δα=0.65032±0.0162; │Δf│= 0.0238±0.0161. The average of generalized dimensions(D_q)for q=0,1,2,the width of the multifractal spectrum(Δα)and the spectrum arms' heights difference(│Δf│)of the segmented versions was slightly greater than the skeletonised versions.CONCLUSION:The multifractal analysis of fundus photographs may be used as a quantitative parameter for the evaluation of the complex three-dimensional structure of the retinal microvasculature as a potential marker for early detection of topological changes associated with retinal diseases. 展开更多
关键词 generalized dimensions multifractal retinal vessel segmentation retinal image analysis retinal microvasculature standard box-counting method
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Effect of Different Conditions on the Structural Color of Konjac Glucomannan Particles 被引量:1
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作者 谭小丹 黄荣勋 +5 位作者 穆若郡 谢丙清 袁毅 王敏 陈涵 庞杰 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第10期1525-1531,共7页
In this paper,molecular dynamics simulation was applied to synthesize a layered structural color from Konjac glucomannan(KGM) and the effect of particle diameter and temperature were investigated. A series of method... In this paper,molecular dynamics simulation was applied to synthesize a layered structural color from Konjac glucomannan(KGM) and the effect of particle diameter and temperature were investigated. A series of methods such as high voltage electric field treatment,the transfer matrix method and the CIE standard colorimetric system were simulated to obtain the chromaticity coordinates and to analyze the color changes of KGM particles. The results revealed that as the particle diameter increases,the structural color of KGM particles deflects towards the yellow wavelength within the visible spectrum; and as the reaction temperature rises,the structural color deflects towards the blue and violet wavelengths within the visible spectrum. 展开更多
关键词 Konjac glucomannan(KGM) structural color transfer matrix method CIE standard chromaticity
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Seismic hazard analysis for central-western Argentina 被引量:2
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作者 Salvador Daniel Gregori Rodolfo Christiansen 《Geodesy and Geodynamics》 2018年第1期25-33,共9页
In this study, we present a PSHA(Probabilistic Seismic Hazard Analysis) for the city of San Juan, which is located in the central-western region of Argentina(30°S-35.5°S; 66.5°W-71°W). In addit... In this study, we present a PSHA(Probabilistic Seismic Hazard Analysis) for the city of San Juan, which is located in the central-western region of Argentina(30°S-35.5°S; 66.5°W-71°W). In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5(Mw) are expected.High values of SA(spectral acceleration)(0.2 and 1 s periods) and PGA(peak ground acceleration) were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures. 展开更多
关键词 Probabilistic seismic hazard analysis Seismic-resistant construction standards Seismic sources Visual cumulative method
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Quantitative Determination of Tetrachlorantraniliprole by(1)^H NMR Spectroscopy with Internal Standard Method
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作者 Lang Jie Dong Yan +2 位作者 Wang Qiang Yang Huibin Yu Haibo 《Plant Diseases and Pests》 CAS 2020年第5期35-37,共3页
[Objective]This study was to establish a rapid,specific and simple method for quantitative determination of tetrachlorantraniliprole by 1H NMR.[Method]1H NMR spectroscopy was acquired with deuterium DMSO as the solven... [Objective]This study was to establish a rapid,specific and simple method for quantitative determination of tetrachlorantraniliprole by 1H NMR.[Method]1H NMR spectroscopy was acquired with deuterium DMSO as the solvent and maleic acid as internal standard under the conditions of temperature 25℃,pulses width 8.0μs,delay time 5 s,and scanning times 8.[Result]The hydrogen proton peaks of tetrachlorantraniliprole(δ=10.55)and maleic acid(δ=6.27)were taken as quantitative peaks.The peak area ratio y(As/Ar)and mass ratio x(ms/mr)were linearly regressed,and the correlation coefficient was 0.9999.The RSD value of repeatability test was 0.38%,and the RSD value of stability test was 0.77%.The content of tetrachlorantraniliprole was determined as 99.6%.[Conclusion]1H NMR spectroscopy can be used for quantitative determination of tetrachlorantraniliprole without standard reference,which is rapid,accurate and simple. 展开更多
关键词 Tetrachlorantraniliprole qNMR Internal standard method Quantitative determination
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Asymptotic analysis on weakly forced vibration of axially moving viscoelastic beam constituted by standard linear solid model
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作者 王波 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第6期817-828,共12页
The weakly forced vibration of an axially moving viscoelastic beam is inves- tigated. The viscoelastic material of the beam is constituted by the standard linear solid model with the material time derivative involved.... The weakly forced vibration of an axially moving viscoelastic beam is inves- tigated. The viscoelastic material of the beam is constituted by the standard linear solid model with the material time derivative involved. The nonlinear equations governing the transverse vibration are derived from the dynamical, constitutive, and geometrical relations. The method of multiple scales is used to determine the steady-state response. The modulation equation is derived from the solvability condition of eliminating secular terms. Closed-form expressions of the amplitude and existence condition of nontrivial steady-state response are derived from the modulation equation. The stability of non- trivial steady-state response is examined via the Routh-Hurwitz criterion. 展开更多
关键词 axially moving beam weakly forced vibration standard linear solid model method of multiple scales steady-state response
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In-vitro vs in-vivo Inoculation: Screening for Resistance of Australian Rice Genotypes Against Blast Fungus
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作者 Vineela CHALLAGULLA Surya BHATTARAI David J.MIDMORE 《Rice science》 SCIE CSCD 2015年第3期132-137,共6页
To assist with rapid screening for rice blast resistance as a precursor in a breeding program, the susceptibility to rice blast of 13 rice genotypes from Australia was evaluated in May to June 2013 using three distinc... To assist with rapid screening for rice blast resistance as a precursor in a breeding program, the susceptibility to rice blast of 13 rice genotypes from Australia was evaluated in May to June 2013 using three distinct inoculation methods(spot, filter paper and standard methods) at seedling, vegetative and reproductive stages. The results revealed that the spot and filter paper inoculation methods were successful in discerning susceptibility to the rice blast disease(P ≤ 0.05). Disease susceptibility declined significantly from the vegetative to reproductive stages. The standard method was conducted at three different stages for pot plants grown inside the mist house. However, low temperatures did not produce disease symptoms except in a few genotypes. Among the 13 rice genotypes screened, AAT9 expressed a highly resistant response, and AAT4, AAT6, AAT10, AAT11, AAT13, AAT17 and AAT18 expressed resistance at various stages. The results will be useful for selecting elite genotypes for disease tolerance where rice blast is prevalent. In addition, the resistant genotypes can serve as a gene pool used in breeding programmes to develop new resistant genotypes. 展开更多
关键词 spot inoculation filter paper inoculation standard method seedling stage vegetative stage reproductive stage rice blast disease rice genotype
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NONCONFORMING FINITE ELEMENT PENALTY METHOD FOR STOKES EQUATION 被引量:3
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作者 SHI DONGYANG, FENG WEIBING AND LI KAITAI 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1998年第1期53-58,共6页
a special penalty method is presented to improve the accuracy of the standard penalty method for solving Stokes equation with nonconforming finite element.It is shown that this method with a larger penalty parameter c... a special penalty method is presented to improve the accuracy of the standard penalty method for solving Stokes equation with nonconforming finite element.It is shown that this method with a larger penalty parameter can achieve the same accuracy as the standard method with a smaller penalty parameter. The convergence rate of the standard method is just half order of this penalty method when using the same penalty parameter, while the extrapolation method proposed by Faik et al can not yield so high accuracy of convergence.At last, we also get the super convergence estimates for total flux. Received October 14, 1996 1991 MR Subject Classification: 65N30. 展开更多
关键词 Special method Stokes equation standard method.
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Experimental Study on Dispersion of Unconfined Aquifer in a Site of Jilin City
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作者 Weihong Dong Ruiqing Wang 《Frontiers Research of Architecture and Engineering》 2020年第3期76-82,共7页
Dispersion parameter is an important parameter for the establishment of groundwater solute transport model.The dispersion test uses sodium chloride as a tracer,which was conducted in a site in Jilin City.The standard ... Dispersion parameter is an important parameter for the establishment of groundwater solute transport model.The dispersion test uses sodium chloride as a tracer,which was conducted in a site in Jilin City.The standard curve comparison method was used to solve the dispersion parameters of the aquifer under the natural flow field.The test results show that under the natural flow field,the longitudinal dispersion of unconfined aquifer in Jilin City is 0.400m,and the transverse dispersion is 1.933×10-5~6.557×10-3m;while the longitudinal dispersion coefficient is 0.246m2/d,the transverse dispersion coefficient is 1.191×10-5~4.039×10-3m2/d.The above results can provide an important parameter basis for the establishment of groundwater solute transport model,the accurate prediction of temporal and spatial variation of pollutant concentration in groundwater and the formulation of groundwater pollution prevention and control scheme. 展开更多
关键词 Dispersion test Dispersion parameters Standard curve comparison method Unconfined aquifer
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The Latest Status and Progress of Domestic and Foreign Regulations on Cosmetic Efficacy Claims
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作者 Li Yanan Jiang Ligang 《China Detergent & Cosmetics》 2021年第3期46-53,共8页
The supervision and administration of cosmetics and its two supporting documents related to efficacy,cosmetics classification rules and classification catalogue and evaluation standard of cosmetic efficacy claims,have... The supervision and administration of cosmetics and its two supporting documents related to efficacy,cosmetics classification rules and classification catalogue and evaluation standard of cosmetic efficacy claims,have been successively introduced and implemented,making China’s cosmetics industry officially enter the era of efficacy evaluation.In the time window when the new era is coming,the definitions of cosmetics in China and other countries are compared.The latest status and progress of regulations on cosmetic efficacy claims in China and other countries are summarized,and the standard methods or guidance of cosmetic efficacy evaluation at home and abroad are introduced.The enlightenment from the supervision systems of cosmetic efficacy in other cosmetic consumer markets around the world are discussed.In addition,the opportunities and challenges for cosmetic enterprises under the background of cosmetic law reform in China are also prospected. 展开更多
关键词 COSMETICS efficacy claims laws and regulations China Europe and America standard methods evaluation guidelines
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Quantitative Analysis of Fe Content in Iron Ore via External Calibration in Conjunction with Internal Standardization Method Coupled with LIBS 被引量:2
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作者 SHENG Liwen ZHANG Tianlong +2 位作者 WANG Kang TANG Hongsheng LI Hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2015年第1期107-111,共5页
The external calibration in conjunction with internal standardization(ECIS) coupled with laser-induced breakdown spectroscopic(LIBS) technique was proposed to perform the quantitative analysis of Fe content in iro... The external calibration in conjunction with internal standardization(ECIS) coupled with laser-induced breakdown spectroscopic(LIBS) technique was proposed to perform the quantitative analysis of Fe content in iron ore The plasma temperature and the electron number density were calculated to prove that the plasma was under local thermodynamic equilibrium(LTE) conditions and to ensure that the integral intensities of Fe I lines were reasonable. In addition, the result of the quantitative analysis shows a content of (20.26±0.59)% by mass of Fe in the iron ore. It was determined by four calibration curves, drawn for four emission lines of Fe I(373.48, 373.71,404.58 and 438.35 nm) normalized by Mn I line, base on the ECIS method which can eliminate the influence of matrix effect and improve the accuracy of quantitative analysis, compared with the standard addition method. Both the results of these two analytical methods were compared with that listed in the Standard Substance Certificate. The percentage content of Fe in the same sample of iron ore by the ECIS method was (20.17±0.08)% by mass, which shows a good performance to analyze the Fe content of iron ore in combination with LIBS. 展开更多
关键词 Laser-induced breakdown spectroscopy(LIBS) External calibration in conjunction with internal standardization(ECIS) method Chemical analysis Iron ore
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Detection of Phthalate Esters in Environmental Water Samples -Comparison of Nylon6 Nanofibers Mat-based Solid Phase Extraction and Other Conventional Extraction Methods
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作者 Xu, Qian 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2011年第3期567-574,共8页
In this article, a new method for simultaneous determination of six phthalate esters was developed by a combination of electrospun nylon6 nanofibers mat-based solid phase extraction with high performance liquid chroma... In this article, a new method for simultaneous determination of six phthalate esters was developed by a combination of electrospun nylon6 nanofibers mat-based solid phase extraction with high performance liquid chromatography-ultraviolet detector (HPLC-UV). The six phthalate esters were dimethyl phthalate (DMP), diethyl phthalate (DEP), butyl benzyl phthalate (BBP), di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and dioctyl phthalate (DOP). Under optimized conditions, all target analytes in 50 mL environmental water samples could be completely extracted by 2.5 mg nylon6 nanofibers mat and eluted by 100 μL solvent. Compared with C18 cartridges solid phase extraction, C 18 disks solid phase extraction and national standard method (China), nylon6 nanofibers mat-based solid phase extraction was advantageous in aspects of simple and fast operation, low consumption of extraction materials and organic solvents. The four methods were applied to analysis of environment water samples. All the results indicated that the determination values of target compounds with the proposed method were consistent with C18 cartridges and C18 disks solid phase extraction method, and the new method was better than the national standard method in aspects of recovery, LOD and precision. Therefore, nylon6 nanofibers mat has great potential as a novel material for solid phase extraction. 展开更多
关键词 Nylon6 nanofibers mat C18 cartridges C18 disks national standard method phthalate esters highperformance liquid chromatography-ultraviolet detector
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Analysis of volatile flavor compounds in top fermented wheat beer by headspace sampling-gas chromatography 被引量:8
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作者 Li Huimin Li Hongjun +1 位作者 Liu Xiuhua Chen Bing 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2012年第2期67-75,共9页
Headspace sampling-gas chromatography(HS-GC)coupled with an internal standard method(ISM)was developed to analyze the volatile flavor compounds in top fermented wheat beer in the laboratory.Eight compounds,i.e.acetald... Headspace sampling-gas chromatography(HS-GC)coupled with an internal standard method(ISM)was developed to analyze the volatile flavor compounds in top fermented wheat beer in the laboratory.Eight compounds,i.e.acetaldehyde,N-propanol,ethyl acetate,isobutyl alcohol,isoamyl alcohol,isoamyl acetate,ethyl hexanoate and ethyl octanoate were separated and quantified.This method was validated to ensure the quality of the results:the precision was satisfactory with relative standard deviation(RSD)in the range of 1.51%-4.22%,recoveries for all the analytes ranged from 95.15%to 99.85%,and the limits of detection were in the range of 0.0002-0.024 mg/L.Results of real wheat beer samples analyzed using this method showed that the volatile compound concentrations were in the range of 0.08-99.91 mg/L.Results suggested that this method exhibited good reproducibility,selectivity and high precision,and it can be useful for the analysis of routine beer samples. 展开更多
关键词 top fermentation wheat beer flavor detection volatile flavor compounds headspace sampling-gas chromatography internal standard method
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Fast Determination of Phenanthrene in Soil by Gas Chroma- tography-Mass Spectrometry Using Chemometric Resolution and Standard Addition Method 被引量:2
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作者 Weiwei Yu Wensheng Cai Xueguang Shao 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2013年第4期545-550,共6页
A method for fast determination of the component in complex samples by using gas chromatography-mass spectrometry (GC-MS) was developed and used for quantitative analysis of phenanthrene in soils. In the method, win... A method for fast determination of the component in complex samples by using gas chromatography-mass spectrometry (GC-MS) was developed and used for quantitative analysis of phenanthrene in soils. In the method, window independent component analysis (WICA) was used for resolving the mass spectrum and non-negative im- mune algorithm (NNIA) was employed for obtaining the chromatographic profile. Therefore, spectral and chroma- tographic information of a specific component can be obtained from the measured GC-MS data of overlapping and high background. Six soil samples collected from different places were analyzed. The tedious pretreatments in pre- paring the samples and the elution in the separation were simplified for speeding up the analysis. Due to the com- plexity of the matrix, standard addition method was adopted for the final quantification. The applicability of the method was validated with a spiked sample and the results of the six samples are reasonable. 展开更多
关键词 PHENANTHRENE gas chromatography-mass spectrometry standard addition method CHEMOINFORMATICS immune algorithm
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Improved Scheme for Probabilistic Transformation and Teleportation of Multi-Particle Quantum States
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作者 姜敏 张曾科 +1 位作者 李向旭 李慧 《Tsinghua Science and Technology》 SCIE EI CAS 2009年第6期735-738,共4页
In most probabilistic teleportation schemes, if the teleportation fails, the unknown quantum state will be completely ruined. In addition, the frequently proposed high-dimensional unitary operations are very difficult... In most probabilistic teleportation schemes, if the teleportation fails, the unknown quantum state will be completely ruined. In addition, the frequently proposed high-dimensional unitary operations are very difficult to realize experimentally. To maintain the integrity of the unknown quantum state to be teleported, this analysis does not focus attention on the original multi-particle state but seeks to construct a faithful channel with an ancillary particle and a unified high-dimensional unitary operation. The result shows that if the construction of the multi-group Einstein-Podolsky-Rosen pair succeeds, the original multi-particle state can be used to deterministically teleport the unknown quantum state of the entangled multiple particles which avoids undermining the integrity of the unknown state brought about by failure. This unified high-dimensional operation is appealing due to the obvious experimental convenience. 展开更多
关键词 probabilistic teleportation multi-particle state quantum state transfer standard method auxiliary particle BeU-state measurement
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