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- 实验方案
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Texture features analysis on micro-structure of paste backfill based on image analysis technology; 基于图像识别技术的膏体微观结构纹理特征分析;
摘要： The strength of cement-based materials, such as mortar, concrete and cement paste backfill (CPB), depends on its microstructures (e.g. pore structure and arrangement of particles and skeleton). Numerous studies on the relationship between strength and pore structure (e.g., pore size and its distribution) were performed, but the micro-morphology characteristics have been rarely concerned. Texture describing the surface properties of the sample is a global feature, which is an effective way to quantify the micro-morphological properties. In statistical analysis, GLCM features and Tamura texture are the most representative methods for characterizing the texture features. The mechanical strength and section image of the backfill sample prepared from three different solid concentrations of paste were obtained by uniaxial compressive strength test and scanning electron microscope, respectively. The texture features of different SEM images were calculated based on image analysis technology, and then the correlation between these parameters and the strength was analyzed. It was proved that the method is effective in the quantitative analysis on the micro-morphology characteristics of CPB. There is a significant correlation between the texture features and the unconfined compressive strength, and the prediction of strength is feasible using texture parameters of the CPB microstructure.
关键词： cement paste backfill,unconfined compressive strength,Tamura texture,microstructure,quantitative analysis,texture feature,GLCM feature
更新于2025-09-23 15:23:52
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A review on M?+?N theory and its strategies to improve the accuracy of spectrochemical composition analysis of complex liquids
摘要： High-precision spectral analysis for complex liquid components has received much attention in recent years. However, the lack of systematic strategies of measurement and modeling notably appears when multiple internal and external factors vary—e.g., the sample parameters, instruments, and external environment. Many methods have been developed to eliminate these effects. According to the characteristics of error sources and its propagation rules, “M + N” theory integrates and classifies the internal and external factors that affect the analysis of complex liquid components into M factors and N factors systematically. “M” and “N” refers to the M components in a liquid and N interference factors, respectively, and “+” means that the spectral is a response to the interaction of M and N. In this review, “M + N” theory sums up five measurement and modeling strategies used to reduce the effect of various factors on spectral quantitative analysis of complex liquids. Finally, this review summarized the strategies used to improve the accuracy of quantitative analysis of complex liquids and discussed future research directions.
关键词： spectrochemical quantitative analysis,measurement and modeling strategies,Complex liquid,M + N theory
更新于2025-09-23 15:23:52
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New Assay Method Based on Raman Spectroscopy for Enzymes Reacting with Gaseous Substrates
摘要： Enzyme activity is typically assayed by quantitatively measuring the initial and final concentrations of the substrates and/or products over a defined time period. For enzymatic reactions involving gaseous substrates, the substrate concentrations can be estimated either directly by gas chromatography or mass spectrometry, or indirectly by absorption spectroscopy, if the catalytic reactions involve electron transfer with electron mediators that exhibit redox-dependent spectral changes. We have developed a new assay system for measuring the time course of enzymatic reactions involving gaseous substrates based on Raman spectroscopy. This system permits continuous monitoring of the gas composition in the reaction cuvette in a non-invasive manner over a prolonged time period. We have applied this system to the kinetic study of the [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F. This enzyme physiologically catalyzes the reversible oxidation of H2 and also possesses the non-physiological functions of H/D exchange and nuclear spin isomer conversion reactions. The proposed system has the additional advantage of enabling us to measure all of the hydrogenase-mediated reactions simultaneously. Using the proposed system, we confirmed that H2 (the fully exchanged product) is concomitantly produced alongside HD by the H/D exchange reaction in the D2/H2O system. Based on a kinetic model, the ratio of the rate constants of the H/D exchange reaction (k) at the active site and product release rate (kout) was estimated to be 1.9±0.2. The proposed assay method based on Raman spectroscopy can be applied to the investigation of other enzymes involving gaseous substrates.
关键词： kinetic experiment,H/D exchange reaction,quantitative analysis of gaseous substrates,Raman spectroscopy,non-invasive measurement,[NiFe] hydrogenase
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - The analysis of the movement of the genetically modified human skin fibroblasts in culture
摘要： The aim of this study is the comparison of the movement of various types of human dermal fibroblasts with and without genetic modification. Three groups of fibroblasts were cultured and monitored: (1) control group of fibroblasts isolated from human skin (not transduced); (2) transduced with lentivirus bearing EGFP fluorescent marker; (3) transduced with lentivirus bearing DsRed2 fluorescent marker. The experimental sequences of images documenting cells’ movement have been analyzed using image processing methods. The cells’ movement was described by: (1) distance between each two consecutive images/frames, (2) distance and displacement covered by each fibroblast in 30 minutes (3) length of cell crawling cycle, (4) the movement tortuosity coefficient for all fibroblasts in each group. Also shape features such as: area, perimeter, eccentricity, length of the major axis have been analyzed. It appears that the general movement behavior is not changed by the process of transduction but some of its aspects are modified. The efficiency of movement in the sense of distance covered and region penetration is decreased because of cells’ morphology. Transduced cells are less polarized and develop extra podia during their crawling.
关键词： EGFP modified cell,DsRed2 modified cell,genetically modified cell,image analysis,quantitative analysis of cells’ movement,quantitative analysis of shape,human skin fibroblast
更新于2025-09-23 15:22:29
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[IEEE 2018 37th Chinese Control Conference (CCC) - Wuhan (2018.7.25-2018.7.27)] 2018 37th Chinese Control Conference (CCC) - On-line Detection and Analysis of Alloy Steel Elements Based on the LIBS Technology and Random Forest Regression
摘要： The Laser Induced Breakdown Spectroscopy (LIBS) technology can be used to detect the elements in the alloy steel in real time. Quantitative analysis method of the traditional LIBS technology mainly has the calibration method and calibration free method, but there are two shortcomings: low prediction accuracy and over fitting. Random Forest Regression (RFR) algorithm can be used for classification and regression, can effectively avoid 'overfitting' phenomenon. Therefore, in this paper, we combine the random forest regression algorithm with laser induced breakdown spectroscopy applied to the detection of the concentration of alloy steel elements in the metallurgy industry. At the same time, compared with partial least squares method based on the LIBS, the results show that the random forest algorithm combined with the LIBS technology has the higher prediction accuracy, lower root mean square error and better robustness.
关键词： PLS,root mean square error,quantitative analysis,LIBS,RFR
更新于2025-09-23 15:22:29
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A Rapid and Sensitive Quantitative Analysis Method for TNT using Raman Spectroscopy
摘要： Raman spectroscopy as a rapid and sensitive qualitative detection method has been applied in many fields; however, it is rarely used for the quantitative purpose due to poor reproducibility of peak area. Here, 2,4,6-trinitrotoluene (TNT) and its two byproducts, 2,4-dinitrotoluence (DNT) and 2,6-DNT, were firstly qualitatively analyzed by Raman spectroscopy and the characteristic parameters were extracted. Then, in the range of 2 %–9 % and 10 %–90 %, the standard curves were established between the area ratio of the characteristic peaks and the content of 2,4-DNT or 2,6-DNT using silver nanoflowers as the enhancing substrate. The fitting correlation for TNT/2,4-DNT or TNT/2,6-DNT system is around 0.99. The peak area ratio of the components exhibits much better data reproducibility than peak area, and the relative error does not exceed 9.3 % for at least six groups of parallel experiments.
关键词： TNT,Quantitative analysis,2,4-DNT,2,6-DNT,Raman spectroscopy
更新于2025-09-23 15:22:29
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Optimization of Parameters for Quantitative Analysis of <sup>123</sup> I-ioflupane SPECT Images for Monitoring of Progression of Parkinson's Disease
摘要： Objectives: Quantitative assessment of dopamine transporter (DAT) imaging can aid in diagnosing Parkinson’s disease (PD) and assessing disease progression in the context of therapeutic trials. Previously, the software program SBRquant was applied to 123I-ioflupane SPECT images acquired on healthy controls and subjects with PD. Earlier work on optimization of the parameters for differentiating between controls and subjects with dopaminergic deficits is extended here for maximizing change measurements associated with disease progression on longitudinally acquired scans. Methods: Serial 123I-ioflupane SPECT imaging for 51 subjects with PD (conducted approximately 1 year apart) were downloaded from the Parkinson’s Progression Markers Initiative database. The software program SBRquant calculates the Striatal Binding Ratio (SBR) separately for the left and right caudate and putamen regions of interest (ROI). Parameters were varied to evaluate the number of summed transverse slices and the positioning of the striatal ROIs for determining signal to noise associated with their annual rate of change in SBR. The parameters yielding the largest change of the lowest putamen's SBR from scan 1 to scan 2 were determined. Results: For the change from scan 1 to scan 2 in the 51 subjects, the largest annual change was observed when the putamen ROI was placed 3 pixels away from the caudate and by summing 5 central striatal slices. This resulted in an 11.2 ± 4.3% annual decrease in the lowest putamen's SBR for the group. Conclusions: Quantitative assessment of DAT imaging for assessing progression of PD requires specific, optimal parameters different than those for diagnostic accuracy.
关键词： Parkinson's Disease,Dopamine Transporter Imaging,Disease Progression,Quantitative Analysis,123I-ioflupane SPECT
更新于2025-09-23 15:21:21
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Optimization of measuring procedure of farmland soils using laser-induced breakdown spectroscopy
摘要： Laser-induced breakdown spectroscopy (LIBS) is an emerging multi-elemental analytical technique offering fast and simultaneous quantification of soil properties with minimal sample preparation and effective cost. Due to soil heterogeneity, spectral variation however limits the quantitative robustness. In this study, 348 soil samples were collected and prepared for acquisition of LIBS spectra. Influences of shot layer and number on LIBS quality were evaluated by spectral intensity and relative standard deviation (RSD). Effects of shot layer and number and five normalization procedures on LIBS ability to measure soil organic matter (SOM), total nitrogen (TN), and total soluble salt content (TSC), were evaluated using partial least squares regression (PLSR). Increasing shot number reduced LIBS spectral variance, thereby improving the quantitative accuracy of selected soil properties. Deep shot layers (4th or 5th shot layers) reduced the intensities of soil spectra and thereby decreased the quantitative accuracy for TSC. However, deep shot layers improved the SOM and TN prediction performances. Among the normalization approaches, the method based on the correction of Si line (DS) showed superior performance for improving quantitation of SOM and TN. The arithmetic average method (AA) was best for TSC prediction. Optimization of shot layer, number and normalization procedures of LIBS spectra resulted in fair prediction of SOM (residual prediction deviation of validation set, RPDV = 1.608), good prediction of TN (RPDV = 1.836), and very good quantitative analysis of TSC (RPDV = 2.456). Therefore, our findings illustrate very good potential for improving the quantitative accuracy of the LIBS soil spectra.
关键词： quantitative analysis,shot layer,soil properties,shot number,normalization methods,Laser-induced breakdown spectroscopy
更新于2025-09-23 15:19:57
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Lens-to-sample distance effect on the quantitative analysis of steel by laser-induced breakdown spectroscopy
摘要： The focusing position of the laser affects the characteristics of the laser-induced plasma, which in turn influences the signal stability and the quantitative analysis of laser-induced breakdown spectroscopy. In this study, six standard alloy steels are used as the samples, and the trace elements including Si, Mn, Cr are quantitatively analyzed by internal standard method. The variations of line intensity, background noise intensity, signal-to-background ratio (SBR), detecting sensitivity and detection of limit (LOD) of the element with lens-to-sample distance (LTSD) were investigated. The results show that both the intensities of the analytical line and the background noise reached a maximum when the LTSD is 94 mm. While the corresponding SBR is relatively low. For quantitative analysis, it is observed that the change of the detection sensitivity with LTSD has the similar trend with that of SBR. That is, the detection sensitivity has a lower value when the LTSD is 94mm. However, when the LTSD changes from 93mm to 99mm, LODs of the three elements are maintained at a small value. The present results indicate that for quantitative analysis of LIBS, the intensities of the analytical line and the background noise should be comprehensively considered when optimizing the laser focusing position.
关键词： Laser-induced breakdown spectroscopy,Quantitative analysis,Line intensity,Lens-to-sample distance
更新于2025-09-23 15:19:57
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Qualitative and Quantitative Distinction of <i>ortho</i> -, <i>meta</i> -, and <i>para</i> -Fluorotoluene by Means of Chirped Femtosecond Laser Ionization
摘要： Femtosecond-laser ionization mass spectrometry (fs-LIMS) is demonstrated to be a powerful analytical method providing access to the qualitative distinction of structural isomers of ortho-, meta-, and para-fluorotoluene. The key point of the approach presented is a systematic variation of the spectral phase of the fs-laser pulses, which characteristically affects the fragmentation pattern observed in the mass spectra. Variation of the linear chirp parameter is also helpful for rationalizing the fragmentation mechanism. Ultimately two ternary mixtures of the three title isomers are quantitatively analyzed in situ with an accuracy of 5% for the molar fractions.
关键词： structural isomers,Femtosecond-laser ionization mass spectrometry,fragmentation pattern,spectral phase,quantitative analysis,fluorotoluene
更新于2025-09-23 15:19:57