Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'...Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.展开更多
The fluorescence spectrum of the ether-water solution excited by the ultraviolet light with the wavelength of 245 nm is experimentally detected. Based on the second derivative analysis, the fluorescence spectrum of th...The fluorescence spectrum of the ether-water solution excited by the ultraviolet light with the wavelength of 245 nm is experimentally detected. Based on the second derivative analysis, the fluorescence spectrum of the ether-water solution is used as Gaussian decomposition and seven Gaussian spectral lines are obtained. The center wavelength, the peak intensity and the half peak bandwidth of each Gaussian spectral line are measured, and the multi-peak fitting is made by using Gaussian primitive parameters. The highest and the lowest oscillation energy level differences in the ground state of each Gaussian spectrum are calculated. It is found that there are seven types of luminescent association molecules formed by ether and water molecules in different configurations existed in the solution. The location of each optimum absorption wavelength and the half peak bandwidth of the Gaussian spectral line is different. The energy level difference with the central wavelength of 304 nm attains the maximum value The result can contribute to the study of the molecular association in ether-water solution.展开更多
Wastewater dissolved organic matter （DOM） from different processing stages of a sewage treatment plant in Xiamen was characterized using fluorescence and absorption spectroscopy. Parallel factor analysis modeling of...Wastewater dissolved organic matter （DOM） from different processing stages of a sewage treatment plant in Xiamen was characterized using fluorescence and absorption spectroscopy. Parallel factor analysis modeling of excitation-emission matrix spectra revealed five fluorescent components occurring in sewage DOM： one protein-like （C1）, three humic-like （C2, C4 and C5） and one xenobiotic-like （C3） components. During the aerated grit chamber and primary sedimentation tank stage, there was only a slight decrease in fluorescence intensity and the absorption coefficient at 350 nm （a 350 ）. During the second aeration stage, high concentration of protein-like and short-wavelength-excited humic-like components were significantly degraded accompanied by significant loss of DOC （80%） and a 350 （30%）, indicating that C1 and C2 were the dominant constituents of sewage DOM. As a result, long-wavelength- excited C4 and C5 became the dominant humic-like components and the DOM molecular size inferred from the variation of spectral slope S （300–650 nm） and specific absorption （a 280 /DOC） increased. Combination use of F max of C1 and the ratio of C1/C5, or a 350 may provide a quantitative indication for the relative amount of raw or treated sewage in aquatic environment.展开更多
The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectr...The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.展开更多
A method was developed for content determination of Na, Mg, A1, Si, P,S, C1, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Nb, Zr, Y, Sr, Rb, Ba, La and Ce etc. covering 26 major, minor, and trace elements in marine sedim...A method was developed for content determination of Na, Mg, A1, Si, P,S, C1, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Nb, Zr, Y, Sr, Rb, Ba, La and Ce etc. covering 26 major, minor, and trace elements in marine sediment samples using fused glass disc by X-ray Fluorescence spectrometry. Calibration was made using marine sediment certified reference materials and the synthetic standard samples prepared by mixing several marine sediments with stream sediment and carbonate standard samples in different proportions. The matrix effect was corrected using theoretical alpha coefficients, experience coefficients and the scattered radiation as the internal standard （for the trace elements）. The accuracy of the method was evaluated by analysis of certified reference materials GBW07314, GBW07334 and GSMS6. The results are in good agreement with the certified values of the standards with RSD less than 2.60%, except for Y, Cr, Ga, Ce, La, Nb, Rb, and V with RSD less than 9.0% （n=12）.展开更多
Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in therm...Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.展开更多
It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an...It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.展开更多
An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis （PARAFAC） and CHEMTAX. The PARAFAC model was applied to fluo-rescence exc...An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis （PARAFAC） and CHEMTAX. The PARAFAC model was applied to fluo-rescence excitation-emission matrix （EEM） of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis （BDA）. Then the reference fluo-rescent component ratio matrix was constructed for CHEMTAX, and the EEM-PARAFAC-CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios （CDRs） when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacil-lariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ.展开更多
Aflatoxin B1(AFB1)is one of the most common mycotoxins that threatens human health.As singlestranded oligonucleotides with high affinity and specificity,aptamers have incomparable effect on the targeted detection of A...Aflatoxin B1(AFB1)is one of the most common mycotoxins that threatens human health.As singlestranded oligonucleotides with high affinity and specificity,aptamers have incomparable effect on the targeted detection of AFB1.Herein,after 11 rounds of selection and analysis using a modified affinity chromatography-based SELEX strategy,the truncated 37 nt aptamer AF11-2 was successfully obtained.The aptamer shows good detection performance for AFB1,and can sensitively detect AFB1 in the range of 100-1000 nmol/L,with a detection limit of 42 nmol/L.In the detection of pretreated edible peanut oil samples,AF11-2 aptamer also showed a high recovery rate and good stability for AFB1,and achieved satisfactory results.In addition,AF11-2 aptamer can significantly enhance the fluorescence ability of AFB1,which is not available in traditional Afla17-2-3 aptamer.After molecular docking analysis,it was found that AF11-2 and Afla17-2-3 had different nucleotide binding sites for AFB1.Afla17-2-3 binds to the carbonyl O of AFB1,while AF11-2 binds to the pyrrolic O of AFB1,which may be the main reason that AF11-2 can enhance the fluorescence of AFB1.展开更多
This work investigated the application of several fluorescence excitation–emission matrix analysis methods as natural organic matter（NOM） indicators for use in predicting the formation of trihalomethanes（THMs） an...This work investigated the application of several fluorescence excitation–emission matrix analysis methods as natural organic matter（NOM） indicators for use in predicting the formation of trihalomethanes（THMs） and haloacetic acids（HAAs）. Waters from four different sources（two rivers and two lakes） were subjected to jar testing followed by 24 hr disinfection by-product formation tests using chlorine. NOM was quantified using three common measures： dissolved organic carbon, ultraviolet absorbance at 254 nm, and specific ultraviolet absorbance as well as by principal component analysis, peak picking,and parallel factor analysis of fluorescence spectra. Based on multi-linear modeling of THMs and HAAs, principle component（PC） scores resulted in the lowest mean squared prediction error of cross-folded test sets（THMs： 43.7（μg/L）^2, HAAs： 233.3（μg/L）^2）. Inclusion of principle components representative of protein-like material significantly decreased prediction error for both THMs and HAAs. Parallel factor analysis did not identify a protein-like component and resulted in prediction errors similar to traditional NOM surrogates as well as fluorescence peak picking. These results support the value of fluorescence excitation–emission matrix–principal component analysis as a suitable NOM indicator in predicting the formation of THMs and HAAs for the water sources studied.展开更多
X-ray fluorescence (XRF) analysis utilizes particle size which is resulted from milling of a material. The milling ensures uniform and fine grained powder. The finer and more uniform the particle size is, the better t...X-ray fluorescence (XRF) analysis utilizes particle size which is resulted from milling of a material. The milling ensures uniform and fine grained powder. The finer and more uniform the particle size is, the better the result and easier it is for material quality control. To ensure uniformity in particle size and finer powder, a comparative analysis was conducted with different grinding aids and pressed pellet method was used in obtaining analysis results. Pressed pellets of cement raw meal sample milled with different grinding aids (graphite, aspirin and lithium borate) were subjected to XRF. Graphite produced better particle size uniformity with a corresponding standard deviation that made quality control of raw meal easier and better than aspirin and lithium borate.展开更多
Dissolved organic matter (DOM) can be originated from autochthonous or allochthonous sources, where allochthonous DOM can be from pedogenic sources (humic substances—HSs) or anthropogenicsources (wastewater). The ana...Dissolved organic matter (DOM) can be originated from autochthonous or allochthonous sources, where allochthonous DOM can be from pedogenic sources (humic substances—HSs) or anthropogenicsources (wastewater). The analysis of fluorescence emission, excitation, synchronous or excitation-emission matrix (EEM) have been used to identify the main source or probable contribution of dissolved compounds, such as humic acids (HA), fulvic acids (FA) and dissolved organic carbon (DOC) from sewage, but does not quantify. Fluorescence emission is a powerful technique to detect and qualify organic dissolved compounds but fails in quantitative aspects. In this work, we propose an in situ method for direct determination of DOC using synchronous fluorescence spectra with independent component analysis (ICA). Well known standard solutions were used for method development and validation. In this work, we show that it is possible to predict the number of independent contributions using an unsupervised method based on iterative Principal Component Analysis and Independent Component Analysis (PCA-ICA) approach over combined matrix results. Within these results it’s also possible to see that with a very small amount of independent components it is possible to describe environmental samples of HA, FA and primary productivity (PP).展开更多
Objective To compare the roles of fluorescence in situ hybridization （FISH） and karyotype analysis on chorionic villus in spontaneous abortion. Methods A total of 201 cases were included in this study and were rando...Objective To compare the roles of fluorescence in situ hybridization （FISH） and karyotype analysis on chorionic villus in spontaneous abortion. Methods A total of 201 cases were included in this study and were randomly divided into 2 groups by the same gestational age. The villi from 100 cases （group A） were cultured and used for karyotype analysis, while the uncultured villi from 101 women （group B） were used for FISH. A case was randomly selected from pregnant patients of 6-11 weeks at each gestational week in each group, 6 cases from each group and a total of 12 cases were analyzed by FISH and karyotype at the same time. Results The successful karyotype analysis rate was 66. 0%, and the abnormality karyotype rate was 30.3%; FISH success analysis rate was 100%, and the abnormality rate was 46. 5%; there were significant differences between FISH and karyotype analysis （P=0.036）. Conclusion There were obvious differences between the two techniques. FISH was more successfully analyzed, and was used to more precisely determine fetal chromo- some number. It is an effective way to determine abnormal chromosome by integrating FISH and karyotype analysis in spontaneous abortion.展开更多
One new polymer [Co（L）（H2O）2]n（1） was synthesized by 4-（ethoxycarbonyl）-5-methyl-1H-1,2,3-triazole-1-carboxylic acid（Emtc） under the in situ solvent thermal reaction（H2L = 1-（carboxymethyl）-5-methyl-1H-1,...One new polymer [Co（L）（H2O）2]n（1） was synthesized by 4-（ethoxycarbonyl）-5-methyl-1H-1,2,3-triazole-1-carboxylic acid（Emtc） under the in situ solvent thermal reaction（H2L = 1-（carboxymethyl）-5-methyl-1H-1,2,3-triazole-4-carboxylic acid）. The title complex performs a wave-like 2D framework and the ligand H2L demonstrates the coordination mode as μ4-η-2：η-1η-1：η-1. The crystal structure has been established by single-crystal X-ray diffraction, and characterized by FT-IR. Fluorescent property was investigated in this work. Hirshfeld surface analysis has also been carried out on 1, and obvious main intermolecular interactions are observed.展开更多
In order to explore researches about the chromosome karyotype analysis and fluorescence in situ hybridization(FISH) technology in China,using the bibliometric method,taking " fluorescence in situ hybridization(FI...In order to explore researches about the chromosome karyotype analysis and fluorescence in situ hybridization(FISH) technology in China,using the bibliometric method,taking " fluorescence in situ hybridization(FISH) " and " chromosome" as key words,this paper made a statistical analysis on the literature published in China National Knowledge Infrastructure(CNKI) during 2002-2016.The results indicated that the number of papers published in 2002 was the smallest(37),while the number of papers published in 2012 was the largest(125).In terms of the distribution of organizations of authors,in 1201 papers,11 organizations published papers ≥15,accounting for 21.65%.In terms of distribution of papers published by different periodicals,11 periodicals published papers ≥10,accounting for 17.65%.In terms of the papers supported by foundation projects,in all papers searched,377 papers were supported by foundation projects,accounting for 31.39%.In terms of the distribution of doctoral and master's dissertations,259 papers were master's dissertations,accounting for 21.57%;92 papers were doctoral dissertations,accounting for 7.66%.展开更多
Fast chlorophyll fluorescence parameters are widely used to characterize the photosynthetic efficiency of plants. In this study, a genome-wide association analysis was used to detect key single-nueleotide polymorphis...Fast chlorophyll fluorescence parameters are widely used to characterize the photosynthetic efficiency of plants. In this study, a genome-wide association analysis was used to detect key single-nueleotide polymorphisms （SNPs） associated with fast chlorophyll fluorescence parameters using more than 560 000 SNPs in a maize panel consisting of 404 inbred lines. In four fidd environments, 41 SNPs were detected to be associated with five fast chlorophyll fluorescence parameters, including ABS/CS0, ET0/CS0, TR0/ABS, ET0/TR0 and Pies. Among these identified SNPs, 8, 6, 18, 4 and 5 were significantly associated with ET0/TR0, ABS/ CS0, TR0/ABS, ET0/CS, and Plcs, respectively. These SNPs will help to discover genes for chlorophyll fluorescence parameters, better understand the genetic basis of photosynthesis, and assist in developing marker-assisted selection breeding programs in maize.展开更多
X-ray mass absorption coefficients play an important role in the accu racy of any XRF intensity calculation. It is necessary to determine the proper schemes for providing satisfying values μ/ρ. In this work we exami...X-ray mass absorption coefficients play an important role in the accu racy of any XRF intensity calculation. It is necessary to determine the proper schemes for providing satisfying values μ/ρ. In this work we examined and compared various schemes. A program based on the existing schemes to provide more accurate and convenient μ/ρ values was then introduced. The results from the program appears to be tolerable.展开更多
Synchrotron radiation X-ray fluorescence （SR-XRF） approach was applied to analyzing of Chinstrap penguin （ Pygoscelis Antarctica） cortical bone. The method enabled the in situ determination of Ca and P concentrati...Synchrotron radiation X-ray fluorescence （SR-XRF） approach was applied to analyzing of Chinstrap penguin （ Pygoscelis Antarctica） cortical bone. The method enabled the in situ determination of Ca and P concentrations and the Ca/P ratio in cortical bone. The preliminary results show that ： （ 1 ） there is the bone site-related difference for Ca and P concentrations. The mean values for the investigated parameters （ on a dry-weight basis） are： 30.7% （Ca） and 14.9% （P） for the femoral cortical bone, 21.4% （Ca） and 11.5% （P） for wing cortical bone. （2） The variation for the Ca/P ratio in cortical bone is lower than those for Ca and P separately. This is in agreement with the previous report that the specificity of the Ca/P ratio is better than that of Ca and P concentrations and is more reliable for the diagnosis of bone disorders. The authors suggest that further studies be conducted to establish norreal values of Ca, P and Ca/P ratio for polar animals and provide a basis for the diagnosis of bone disorders.展开更多
文摘Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.
基金Supported by the Natural Science Foundation of Jiangsu Province(BK2007204)the Natural Sci-ence Foundation of Educational Department of Jiangsu Province(07KJD140208)~~
文摘The fluorescence spectrum of the ether-water solution excited by the ultraviolet light with the wavelength of 245 nm is experimentally detected. Based on the second derivative analysis, the fluorescence spectrum of the ether-water solution is used as Gaussian decomposition and seven Gaussian spectral lines are obtained. The center wavelength, the peak intensity and the half peak bandwidth of each Gaussian spectral line are measured, and the multi-peak fitting is made by using Gaussian primitive parameters. The highest and the lowest oscillation energy level differences in the ground state of each Gaussian spectrum are calculated. It is found that there are seven types of luminescent association molecules formed by ether and water molecules in different configurations existed in the solution. The location of each optimum absorption wavelength and the half peak bandwidth of the Gaussian spectral line is different. The energy level difference with the central wavelength of 304 nm attains the maximum value The result can contribute to the study of the molecular association in ether-water solution.
基金supported by the National Natural Science Foundation of China(No.40776041,40676046)the National High Technology Research and Development Program of China(No.2007AA091704)the Program for New Century Excellent Talents in Fujian Province University
文摘Wastewater dissolved organic matter （DOM） from different processing stages of a sewage treatment plant in Xiamen was characterized using fluorescence and absorption spectroscopy. Parallel factor analysis modeling of excitation-emission matrix spectra revealed five fluorescent components occurring in sewage DOM： one protein-like （C1）, three humic-like （C2, C4 and C5） and one xenobiotic-like （C3） components. During the aerated grit chamber and primary sedimentation tank stage, there was only a slight decrease in fluorescence intensity and the absorption coefficient at 350 nm （a 350 ）. During the second aeration stage, high concentration of protein-like and short-wavelength-excited humic-like components were significantly degraded accompanied by significant loss of DOC （80%） and a 350 （30%）, indicating that C1 and C2 were the dominant constituents of sewage DOM. As a result, long-wavelength- excited C4 and C5 became the dominant humic-like components and the DOM molecular size inferred from the variation of spectral slope S （300–650 nm） and specific absorption （a 280 /DOC） increased. Combination use of F max of C1 and the ratio of C1/C5, or a 350 may provide a quantitative indication for the relative amount of raw or treated sewage in aquatic environment.
基金supported by the National Key R&D Project of China(No.2017YFC0602100)the National Natural Science Foundation of China(No.41774147)Sichuan Science and Technology Support Program(No.2015GZ0272)
文摘The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.
基金Supported by China Ministry of Science and Technology (2000DEB20081)China Ocean Mineral Resources R&D Association (COMRA) (No.DY105-05-01-05)+1 种基金China Ministry of Education(No.205089)China National Natural Science Foundation (No.40076015)
文摘A method was developed for content determination of Na, Mg, A1, Si, P,S, C1, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Nb, Zr, Y, Sr, Rb, Ba, La and Ce etc. covering 26 major, minor, and trace elements in marine sediment samples using fused glass disc by X-ray Fluorescence spectrometry. Calibration was made using marine sediment certified reference materials and the synthetic standard samples prepared by mixing several marine sediments with stream sediment and carbonate standard samples in different proportions. The matrix effect was corrected using theoretical alpha coefficients, experience coefficients and the scattered radiation as the internal standard （for the trace elements）. The accuracy of the method was evaluated by analysis of certified reference materials GBW07314, GBW07334 and GSMS6. The results are in good agreement with the certified values of the standards with RSD less than 2.60%, except for Y, Cr, Ga, Ce, La, Nb, Rb, and V with RSD less than 9.0% （n=12）.
基金supported by National Energy R&D Center of Petroleum Refining Technology of China(RIPP,SINOPEC)National Key Research and Development Program of China(No.2017YFA0304203)+5 种基金Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R70)National Natural Science Foundation of China(Nos.61975103,61875108,61775125 and 11434007)Industrial Application Innovation Project(No.627010407)Scientific and Technological Innovation Project of Shanxi Gemeng US-China Clean Energy R&D Center Co.,Ltd111 Project(D18001)Fund for Shanxi‘1331KSC’。
文摘Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.
基金Supported by the NationalNaturalScience Foundation of China( No. 2 0 175 0 1) and U niversity Key Teachers Programdirected under the Ministry of Education ofP.R.China( No. 2 0 0 0 - 6 5 )
文摘It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.
基金The National Natural Science Foundation of China under contract Nos 41376106 and 41276069
文摘An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis （PARAFAC） and CHEMTAX. The PARAFAC model was applied to fluo-rescence excitation-emission matrix （EEM） of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis （BDA）. Then the reference fluo-rescent component ratio matrix was constructed for CHEMTAX, and the EEM-PARAFAC-CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios （CDRs） when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacil-lariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ.
基金supported by the National Natural Science Foundation of China(Nos.32071392,21775160 and 31900999)the Natural Science Foundation of Jiangsu Province(No.BE2020766)the Science Foundation of Jiangxi Province(No.20192ACB21033)。
文摘Aflatoxin B1(AFB1)is one of the most common mycotoxins that threatens human health.As singlestranded oligonucleotides with high affinity and specificity,aptamers have incomparable effect on the targeted detection of AFB1.Herein,after 11 rounds of selection and analysis using a modified affinity chromatography-based SELEX strategy,the truncated 37 nt aptamer AF11-2 was successfully obtained.The aptamer shows good detection performance for AFB1,and can sensitively detect AFB1 in the range of 100-1000 nmol/L,with a detection limit of 42 nmol/L.In the detection of pretreated edible peanut oil samples,AF11-2 aptamer also showed a high recovery rate and good stability for AFB1,and achieved satisfactory results.In addition,AF11-2 aptamer can significantly enhance the fluorescence ability of AFB1,which is not available in traditional Afla17-2-3 aptamer.After molecular docking analysis,it was found that AF11-2 and Afla17-2-3 had different nucleotide binding sites for AFB1.Afla17-2-3 binds to the carbonyl O of AFB1,while AF11-2 binds to the pyrrolic O of AFB1,which may be the main reason that AF11-2 can enhance the fluorescence of AFB1.
基金funded in part by the Canadian Water Network and the Natural Sciences and Engineering Research Council of Canada Chair in Drinking Water Research at the University of Toronto
文摘This work investigated the application of several fluorescence excitation–emission matrix analysis methods as natural organic matter（NOM） indicators for use in predicting the formation of trihalomethanes（THMs） and haloacetic acids（HAAs）. Waters from four different sources（two rivers and two lakes） were subjected to jar testing followed by 24 hr disinfection by-product formation tests using chlorine. NOM was quantified using three common measures： dissolved organic carbon, ultraviolet absorbance at 254 nm, and specific ultraviolet absorbance as well as by principal component analysis, peak picking,and parallel factor analysis of fluorescence spectra. Based on multi-linear modeling of THMs and HAAs, principle component（PC） scores resulted in the lowest mean squared prediction error of cross-folded test sets（THMs： 43.7（μg/L）^2, HAAs： 233.3（μg/L）^2）. Inclusion of principle components representative of protein-like material significantly decreased prediction error for both THMs and HAAs. Parallel factor analysis did not identify a protein-like component and resulted in prediction errors similar to traditional NOM surrogates as well as fluorescence peak picking. These results support the value of fluorescence excitation–emission matrix–principal component analysis as a suitable NOM indicator in predicting the formation of THMs and HAAs for the water sources studied.
文摘X-ray fluorescence (XRF) analysis utilizes particle size which is resulted from milling of a material. The milling ensures uniform and fine grained powder. The finer and more uniform the particle size is, the better the result and easier it is for material quality control. To ensure uniformity in particle size and finer powder, a comparative analysis was conducted with different grinding aids and pressed pellet method was used in obtaining analysis results. Pressed pellets of cement raw meal sample milled with different grinding aids (graphite, aspirin and lithium borate) were subjected to XRF. Graphite produced better particle size uniformity with a corresponding standard deviation that made quality control of raw meal easier and better than aspirin and lithium borate.
文摘Dissolved organic matter (DOM) can be originated from autochthonous or allochthonous sources, where allochthonous DOM can be from pedogenic sources (humic substances—HSs) or anthropogenicsources (wastewater). The analysis of fluorescence emission, excitation, synchronous or excitation-emission matrix (EEM) have been used to identify the main source or probable contribution of dissolved compounds, such as humic acids (HA), fulvic acids (FA) and dissolved organic carbon (DOC) from sewage, but does not quantify. Fluorescence emission is a powerful technique to detect and qualify organic dissolved compounds but fails in quantitative aspects. In this work, we propose an in situ method for direct determination of DOC using synchronous fluorescence spectra with independent component analysis (ICA). Well known standard solutions were used for method development and validation. In this work, we show that it is possible to predict the number of independent contributions using an unsupervised method based on iterative Principal Component Analysis and Independent Component Analysis (PCA-ICA) approach over combined matrix results. Within these results it’s also possible to see that with a very small amount of independent components it is possible to describe environmental samples of HA, FA and primary productivity (PP).
文摘Objective To compare the roles of fluorescence in situ hybridization （FISH） and karyotype analysis on chorionic villus in spontaneous abortion. Methods A total of 201 cases were included in this study and were randomly divided into 2 groups by the same gestational age. The villi from 100 cases （group A） were cultured and used for karyotype analysis, while the uncultured villi from 101 women （group B） were used for FISH. A case was randomly selected from pregnant patients of 6-11 weeks at each gestational week in each group, 6 cases from each group and a total of 12 cases were analyzed by FISH and karyotype at the same time. Results The successful karyotype analysis rate was 66. 0%, and the abnormality karyotype rate was 30.3%; FISH success analysis rate was 100%, and the abnormality rate was 46. 5%; there were significant differences between FISH and karyotype analysis （P=0.036）. Conclusion There were obvious differences between the two techniques. FISH was more successfully analyzed, and was used to more precisely determine fetal chromo- some number. It is an effective way to determine abnormal chromosome by integrating FISH and karyotype analysis in spontaneous abortion.
基金Supported by the financial support of Fundamental Research Funds for the Central Universities(3207045420)Jiangsu Ainaji Neoenergy Science&Technology Co.,Ltd.(8507040091)
文摘One new polymer [Co（L）（H2O）2]n（1） was synthesized by 4-（ethoxycarbonyl）-5-methyl-1H-1,2,3-triazole-1-carboxylic acid（Emtc） under the in situ solvent thermal reaction（H2L = 1-（carboxymethyl）-5-methyl-1H-1,2,3-triazole-4-carboxylic acid）. The title complex performs a wave-like 2D framework and the ligand H2L demonstrates the coordination mode as μ4-η-2：η-1η-1：η-1. The crystal structure has been established by single-crystal X-ray diffraction, and characterized by FT-IR. Fluorescent property was investigated in this work. Hirshfeld surface analysis has also been carried out on 1, and obvious main intermolecular interactions are observed.
基金Supported by Project of National Natural Science Foundation(31160292)Crop Discipline Construction Project of Tibet Agricultural and Animal Husbandry College(2015ZWXKJS&2016ZWXKJS)
文摘In order to explore researches about the chromosome karyotype analysis and fluorescence in situ hybridization(FISH) technology in China,using the bibliometric method,taking " fluorescence in situ hybridization(FISH) " and " chromosome" as key words,this paper made a statistical analysis on the literature published in China National Knowledge Infrastructure(CNKI) during 2002-2016.The results indicated that the number of papers published in 2002 was the smallest(37),while the number of papers published in 2012 was the largest(125).In terms of the distribution of organizations of authors,in 1201 papers,11 organizations published papers ≥15,accounting for 21.65%.In terms of distribution of papers published by different periodicals,11 periodicals published papers ≥10,accounting for 17.65%.In terms of the papers supported by foundation projects,in all papers searched,377 papers were supported by foundation projects,accounting for 31.39%.In terms of the distribution of doctoral and master's dissertations,259 papers were master's dissertations,accounting for 21.57%;92 papers were doctoral dissertations,accounting for 7.66%.
基金Supported by Natural Science Foundation of Jiangsu Province(BK20141272)National Natural Science Foundation of China(31571669,91535106)+2 种基金Prospective Joint Project of Industry-University-Research Institute Corporation of Jiangsu Province(BY2016069-09)Key Agricultural Science and Technology Research and Development Program of Jiangsu Province(BE2014353)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Fast chlorophyll fluorescence parameters are widely used to characterize the photosynthetic efficiency of plants. In this study, a genome-wide association analysis was used to detect key single-nueleotide polymorphisms （SNPs） associated with fast chlorophyll fluorescence parameters using more than 560 000 SNPs in a maize panel consisting of 404 inbred lines. In four fidd environments, 41 SNPs were detected to be associated with five fast chlorophyll fluorescence parameters, including ABS/CS0, ET0/CS0, TR0/ABS, ET0/TR0 and Pies. Among these identified SNPs, 8, 6, 18, 4 and 5 were significantly associated with ET0/TR0, ABS/ CS0, TR0/ABS, ET0/CS, and Plcs, respectively. These SNPs will help to discover genes for chlorophyll fluorescence parameters, better understand the genetic basis of photosynthesis, and assist in developing marker-assisted selection breeding programs in maize.
文摘X-ray mass absorption coefficients play an important role in the accu racy of any XRF intensity calculation. It is necessary to determine the proper schemes for providing satisfying values μ/ρ. In this work we examined and compared various schemes. A program based on the existing schemes to provide more accurate and convenient μ/ρ values was then introduced. The results from the program appears to be tolerable.
基金grants from the National Natural Science Foundation of China(Project No.40306001) the Foundation for the Author of National Excellent Doctoral Dissertation of P.R.China(Grant No.200354)from Ministry of Education of China and Chinese Academy of Sciences.It was partially support by BSRF(Project No.SR-03097).
文摘Synchrotron radiation X-ray fluorescence （SR-XRF） approach was applied to analyzing of Chinstrap penguin （ Pygoscelis Antarctica） cortical bone. The method enabled the in situ determination of Ca and P concentrations and the Ca/P ratio in cortical bone. The preliminary results show that ： （ 1 ） there is the bone site-related difference for Ca and P concentrations. The mean values for the investigated parameters （ on a dry-weight basis） are： 30.7% （Ca） and 14.9% （P） for the femoral cortical bone, 21.4% （Ca） and 11.5% （P） for wing cortical bone. （2） The variation for the Ca/P ratio in cortical bone is lower than those for Ca and P separately. This is in agreement with the previous report that the specificity of the Ca/P ratio is better than that of Ca and P concentrations and is more reliable for the diagnosis of bone disorders. The authors suggest that further studies be conducted to establish norreal values of Ca, P and Ca/P ratio for polar animals and provide a basis for the diagnosis of bone disorders.
