Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips

Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.

Quantitative analysis of γ-oryzanol content in cold pressed rice bran oil by TLC-image analysis method

Objective:To develop and validate an image analysis method for quantitative analysis ofγ-oryzanol in cold pressed rice bran oil.Methods:TLC-densitometric and TLC-image analysis methods were developed,validated,and used for quantitative analysis of γ-oryzanol in cold pressed rice bran oil.The results obtained by these two different quantification methods were compared by paired t-test.Results:Both assays provided good linearity,accuracy,reproducibility and selectivity for determination of γ-oryzanol.Conclusions:The TLC-densitomelric and TLC-image analysis methods providett a similar reproducibility,accuracy and selectivity for the quantitative determination of γ-oryzanol in cold pressed rice bran oil.A statistical comparison of the quantitative determinations of γ-oryzanol in samples did not show any statistically significant difference between TLC-densitometric and TLC-image analysis methods.As both methods were found to be equal,they therefore can be used for the determination of γ-oryzanol in cold pressed rice bran oil.

Comparison of Calibration Curve Method and Partial Least Square Method in the Laser Induced Breakdown Spectroscopy Quantitative Analysis

The Laser Induced Breakdown Spectroscopy (LIBS) is a fast, non-contact, no sample preparation analytic technology;it is very suitable for on-line analysis of alloy composition. In the copper smelting industry, analysis and control of the copper alloy concentration affect the quality of the products greatly, so LIBS is an efficient quantitative analysis tech- nology in the copper smelting industry. But for the lead brass, the components of Pb, Al and Ni elements are very low and the atomic emission lines are easily submerged under copper complex characteristic spectral lines because of the matrix effects. So it is difficult to get the online quantitative result of these important elements. In this paper, both the partial least squares (PLS) method and the calibration curve (CC) method are used to quantitatively analyze the laser induced breakdown spectroscopy data which is obtained from the standard lead brass alloy samples. Both the major and trace elements were quantitatively analyzed. By comparing the two results of the different calibration method, some useful results were obtained: both for major and trace elements, the PLS method was better than the CC method in quantitative analysis. And the regression coefficient of PLS method is compared with the original spectral data with background interference to explain the advantage of the PLS method in the LIBS quantitative analysis. Results proved that the PLS method used in laser induced breakdown spectroscopy was suitable for simultaneous quantitative analysis of different content elements in copper smelting industry.

QUANTITATIVE ANALYSIS OF VERY WEAK ACID AND BASE BY pH-FIXED TITRATION METHOD

pH-fixed titration method for the determination of weak acids and bases has been studied in this paper.It is not necessary to know the ionization constant of weak acid or base and the concentration of titrant. This method had been applied to determine phenol,4-aminoantipyrine and glycine,whose ionization constants range from 10^(-10)to 10^(-12).The results were satisfactory.

Improvement of quantitative analysis of molybdenum element using PLS-based approaches for laser-induced breakdown spectroscopy in various pressure environments

An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normalization methods with the partial least squares(PLS) method are developed for quantitative analysis of molybdenum(Mo) element in the multi-component alloy,which is the first wall material in the Experimental Advanced Superconducting Tokamak. In this study, the different spectral normalization methods(total spectral area normalization,background normalization, and reference line normalization) are investigated for reducing the uncertainty and improving the accuracy of spectral measurement. The results indicates that the approach of PLS based on inter-element interference is significantly better than the conventional PLS methods as well as the univariate linear methods in the various pressure for molybdenum element analysis.

Quantitative analysis modeling for the Chem Cam spectral data based on laser-induced breakdown spectroscopy using convolutional neural network

Laser-induced breakdown spectroscopy(LIBS)has been applied to many fields for the quantitative analysis of diverse materials.Improving the prediction accuracy of LIBS regression models is still of great significance for the Mars exploration in the near future.In this study,we explored the quantitative analysis of LIBS for the one-dimensional Chem Cam(an instrument containing a LIBS spectrometer and a Remote Micro-Imager)spectral data whose spectra are produced by the Chem Cam team using LIBS under the Mars-like atmospheric conditions.We constructed a convolutional neural network(CNN)regression model with unified parameters for all oxides,which is efficient and concise.CNN that has the excellent capability of feature extraction can effectively overcome the chemical matrix effects that impede the prediction accuracy of regression models.Firstly,we explored the effects of four activation functions on the performance of the CNN model.The results show that the CNN model with the hyperbolic tangent(tanh)function outperforms the CNN models with the other activation functions(the rectified linear unit function,the linear function and the Sigmoid function).Secondly,we compared the performance among the CNN models using different optimization methods.The CNN model with the stochastic gradient descent optimization and the initial learning rate?=?0.0005 achieves satisfactory performance compared to the other CNN models.Finally,we compared the performance of the CNN model,the model based on support vector regression(SVR)and the model based on partial least square regression(PLSR).The results exhibit the CNN model is superior to the SVR model and the PLSR model for all oxides.Based on the above analysis,we conclude the CNN regression model can effectively improve the prediction accuracy of LIBS.

A quantitative BP neural network analysis of the relationships between ΣREE content and impact factors in the Beibu Gulf

The distribution characteristics of rare earth elements （REE） in bottomsediments are influenced by many factors. Hence, conducting a quantitative analysis isdifficult. A qualitative analysis of the relationships between ΣREE content andprovenance, hydrodynamics, grain size and mineral distribution in the Beibu Gulf showsthat terrestrial rocks control the ΣREE composition. Both weaker hydrodynamics andfiner grain size lead to a higher ΣREE content. Relative curves revealing therelationships between individual impact factors and ΣREE content were obtained fromthe combination of qualitative and quantitative analyses of the BP neural network,which trained the position of samples, gravel content, sand content, silt content, claycontent and clay mineral content. The results are consistent with those of thequantitative analysis. The self-learning algorithm is automatically determined andcalculated quantitatively. The impact of each factor on REEs and how each factorcontrols the ΣREE distribution is identified. Thus, environmental changes and thegeological evolution of the region can be inferred based on curve variation and the geological evolution of the region can be inferred based on curve variation and theactual situation. This method also provides useful theoretical guidance for the analysisof REE enrichment and dispersion.

Quantitative Analysis法在木兰溪水质模型选择中的应用

木兰溪是闽中最大的溪流,为福建省八条主要水系之一.对木兰溪水质模型进行选择可以根据Quantitative Analysis法,由Pe(Peclet Number)的范围来判断污染物在河流三维上的混合情况.通过将木兰溪划分为四个计算(控制)单元,对控制单元4的Pe值进行计算,快速准确地确定了适合木兰溪的简单实用的水质数学模型.

Application of the Quantitative Descriptive Analysis in Cosmetics Sensory Evaluation

The sensory evaluation method was introduced so late in China, and a complete system of this method has not built yet in cosmetics industry. In this article, the application of the Quantitative Descriptive Analysis method in the evaluation of the sensory assessment items are studied. With the SPSS reliability analysis, it was found that the Quantitative Descriptive Analysis method is not suitable for some sensory assessment items.

The Analysis of the Untwisting and Retwisting Methods in Determining the Twist of OE Yarn

The twists of twelve kinds of the cotton OE yarns in different machine twists and different yarn linear density have been determined by one time back twisting and twisting method, triple twisting method and double twisting method. The quantitative analysis of the measurement principles of all the untwisting and retwisting methods has been made by the writers. It is theoretically and practically concluded that for twelve kinds of the cotton OE yarns the difference between the twist determined by triple twisting method and machine twist is the lowest and there is measuring method error in determining the twist of OE yarn by all the untwisting and retwisting methods.

A New Approach to Investigate Students’ Behavior by Using Cluster Analysis as an Unsupervised Methodology in the Field of Education

The problem of taking a set of data and separating it into subgroups where the elements of each subgroup are more similar to each other than they are to elements not in the subgroup has been extensively studied through the statistical method of cluster analysis. In this paper we want to discuss the application of this method to the field of education: particularly, we want to present the use of cluster analysis to separate students into groups that can be recognized and characterized by common traits in their answers to a questionnaire, without any prior knowledge of what form those groups would take (unsupervised classification). We start from a detailed study of the data processing needed by cluster analysis. Then two methods commonly used in cluster analysis are before described only from a theoretical point a view and after in the Section 4 through an example of application to data coming from an open-ended questionnaire administered to a sample of university students. In particular we describe and criticize the variables and parameters used to show the results of the cluster analysis methods.

An analytical method for quantitative estimation of the cytotoxicity of dental alloys using MTT assay,ICP analysis and effective cytotoxicity calculation

The two most important criteria for dental materials are their biofunctional and biocompatible endurance within the anticipated life-span of the dental restoration in the mouth. Biocompatibility relates mainly to the allergenicity and the toxicity of the material. To test the non-specific toxicity of dental materials, in vitro cell culture assays have been developed. For in vitro screening, such tests are recommended to check the cytotoxicity of dental materials (ISO 10993 5). Various studies have already been performed to quantitatively determine the cytotoxicity level of dental alloys. However, as long as only dental alloys and the cell culture technique are applied, it is not possible to determine which of the alloying elements cause the cytotoxicity. Therefore, an analytical method is needed. Wataha et al determined in 1991 the TC50 values of 9 metal cations of various dental casting alloys, using cell culture methods. Kapert et al reported in 1994 a complex in vitro test concept, where the ICP analysis (inductively coupled plasma emission spectroscopy) was introduced to measure the trace elements extracted from various alloys. Experimentelle Zahnheilkunde, Universitts ZMK Klinik Freiburg, Germany (Lü XY and Kappert HF) The aim of the present study was to find a relation between the ICP results, the TC50 value of metal cations, and the cytotoxicity of dental alloys. The cytotoxicity levels of various dental alloys and the TC50 values of 10 metal cations were established using the MTT assay, an effective cell culture of method. Then, the concentrations of the corrosively soluted metal cations in the extracts of the alloys were measured using the ICP method. From all these experimental results it was found that the relation between the effective cytotoxicity Z eff of an alloy, the concentrations C i of i th trace element and the TC50 values T Ci of the i th metal cation can approximately be expressed by Z eff =∑iC i2·T Ci . Two significant applications of this expression are a) The cytotoxicity of an alloy can be estimated by ICP analysis of the extract if the TC50 values of the trace elements are know. b) The cytotoxicity of a new-developed-alloy can be estimated in advance, according to the alloying components.

Stable and unique graphitic Raman internal standard nanocapsules for surface-enhanced Raman spectroscopy quantitative analysis

Graphitic nanomaterials have unique, strong, and stable Raman vibrations that have been widely applied in chemistry and biomedicine. However, utilizing them as internal standards （ISs） to improve the accuracy of surface-enhanced Raman spectroscopy （SERS） analysis has not been attempted. Herein, we report the design of a unique IS nanostructure consisting of a large number of gold nanoparticles （AuNPs） decorated on multilayered graphitic magnetic nanocapsules （AGNs） to quantify the analyte and eliminate the problems associated with traditional ISs. The AGNs demonstrated a unique Raman band from the graphitic component, which was localized in the Raman silent region of the biomolecules, making them an ideal IS for quantitative Raman analysis without any background interference. The IS signal from the AGNs also indicated superior stability, even under harsh conditions. With the enhancement of the decorated AuNPs, the AGN nanostructures greatly improved the quantitative accuracy of SERS, in particular the exclusion of quantitative errors resulting from collection loss and non-uniform distribution of the analytes. The AGNs were further utilized for cell staining and Raman imaging, and they showed great promise for applications in biomedicine.

Quantitative Phase Analysis of the Calcium Silicate Slag as the Residue of Extracting Alumina from High-Alumina Fly Ash

Calcium silicate slag is the residue of process of pre-desilication alkali lime sintering applied in the high-alumina fly ash to extract the alumina.The quantitative phase analysis(QPA) of the calcium silicate slag has been performed by the Rietveld method based on the powder X-ray diffraction(XRD) with the aid of noncommercial software GSAS-EXPGUI.A known weight of crystalline internal standard(10% CaF_2) was added to the calcium silicate slag to calculate the fraction of amorphous phase and other crystalline phases on an absolute basis.Besides,the calcium silicate slag was characterized by X-ray fluorescence(XRF) and thermo gravimetric(TG) differential scanning calorimetry(DSC) to test the QPA results and investigate its other characters.Finally,the results show that the amorphous fraction is 17.5%(hereinafter,the percentages refer to the mass fraction),and the major crystalline phases detected in the calcium silicate slag consist of 23.5% Beta-Ca_2 SiO_4,10.0% bredigite,10.3% Ca_3Al_2O_6(C_3A) and 21.6% CaCO_3.

A new quantitative method in analysing the experiments on short term serial memory

A new quantitative method is introduced into the analysis of the experiments on short term serial memory (STSM). In this method, three parameters are defined to quantitatively represent the performance of memory for item and time order information. These parameters are the divergence, the disorder and the similarity. This method is used in analysing the experiments on visuo-spatial STSM. The results show that the parameters may reflect some characteristics of STSM.

Parametric sensitivity analysis of precipitation and temperature based on multi-uncertainty quantification methods in the Weather Research and Forecasting model

Sensitivity analysis(SA) has been widely used to screen out a small number of sensitive parameters for model outputs from all adjustable parameters in weather and climate models, helping to improve model predictions by tuning the parameters. However, most parametric SA studies have focused on a single SA method and a single model output evaluation function, which makes the screened sensitive parameters less comprehensive. In addition, qualitative SA methods are often used because simulations using complex weather and climate models are time-consuming. Unlike previous SA studies, this research has systematically evaluated the sensitivity of parameters that affect precipitation and temperature simulations in the Weather Research and Forecasting(WRF) model using both qualitative and quantitative global SA methods. In the SA studies, multiple model output evaluation functions were used to conduct various SA experiments for precipitation and temperature. The results showed that five parameters(P3, P5, P7, P10, and P16) had the greatest effect on precipitation simulation results and that two parameters(P7 and P10) had the greatest effect for temperature. Using quantitative SA, the two-way interactive effect between P7 and P10 was also found to be important, especially for precipitation. The microphysics scheme had more sensitive parameters for precipitation, and P10(the multiplier for saturated soil water content) was the most sensitive parameter for both precipitation and temperature. From the ensemble simulations, preliminary results indicated that the precipitation and temperature simulation accuracies could be improved by tuning the respective sensitive parameter values, especially for simulations of moderate and heavy rain.

盐湖卤水中硼酸盐化学形态及Raman光谱定量分析

我国青藏盐湖以富含硼锂而著称,卤水中硼化学赋存状态随湖水化学类型的不同而发生变化,其中以硫酸盐型盐湖卤水中硼酸盐的存在形式变化最为复杂,卤水蒸发过程一般不以固体盐形式结晶析出,而是以多硼物种形式富集于氯化镁饱和老卤中,表现出严重的过饱和性,对后续锂盐和镁盐的分离提取影响较大。开展盐湖卤水体系中硼酸盐化学形态、分布规律及离子间作用机制等溶液化学研究对盐湖资源高效开发具有重要的意义。相比常规拉曼光谱技术,拉曼积分球基于拉曼散射原理可极大地提高激发光的使用效率和拉曼散射信号,对硼酸盐溶液结构检测具有拉曼响应信号强、检出限低、信噪比高等优点,为盐卤复杂体系硼酸盐化学形态的定量分析奠定了基础。利用拉曼积分球开展了盐湖卤水硼酸盐化学形态研究,阐述了卤水蒸发过程多硼酸根离子的变化规律;同时借助响应曲面法进行实验设计与优化,建立了共存盐类干扰回归模型用于盐湖卤水中单硼物种B(OH)_(3)的准确测定。结果表明,盐湖卤水浓缩过程中硼不断聚合生成多聚度硼酸根离子如B_(3)O_(3)(OH)_(4)^(-)和B_(6)O_(7)(OH)_(7)^(2-)等,硼的化学形态变化规律与碱土金属如MgCl_(2)-MgO-2B_(2)O_(3)-H_(2)O体系中硼物种变化一致,但与碱金属溶液体系物种变化差别较大。回归模型对卤水中正硼酸B(OH)_(3)定量分析的相对误差小于5%,准确度较高;阐明了蒸发浓缩过程中B(OH)_(3)物种分布的变化规律,从定量视角初步阐述了卤水富集过程硼酸根离子间的聚合作用关系,可为后续开展盐卤体系多硼物种分布及作用机制研究提供新思路、新方法。

基于Hsp70基因的绵羊肺炎支原体TaqMan检测方法的建立及其遗传演化分析

热休克蛋白70 (heat shock protein 70,Hsp70)是绵羊肺炎支原体(Mycoplasma ovipneumoniae, Movi)的重要膜蛋白,是机体内高度保守的生物分子,但在种间差异大,可作为分子生物学检测的候选靶区。为建立基于Hsp70基因的Movi通用型TaqMan实时荧光定量PCR(qPCR)检测方法,并进一步了解其遗传变异情况,本研究基于GenBank中Movi的Hsp70基因特征,设计特异性的引物及探针,建立了基于Hsp70基因的绵羊肺炎支原体qPCR检测方法。应用建立的检测方法对88份山羊鼻拭子样品及43份疑似羊支原体性肺炎(Mycoplasmal pneumonia of sheep and goats, MPSG)病料进行检测。将检测结果为Movi阳性的肺组织样品进行分离鉴定,并对分离株Hsp70基因进行序列分析。结果显示,建立的qPCR检测方法其相关系数为1.00,扩增效率为96.0%,斜率为-3.411,Y轴截距为37.29。特异性强,与丝状支原体山羊亚种(Mycoplasma mycoides subsp.capri, Mmc)、山羊支原体山羊肺炎亚种(Mycoplasma capricolum subsp.capripneumoniae, Mccp)、莱氏无胆甾原体(Acholeplasmalaidlawii, AL)、无乳支原体(Mycoplasma agalactiae, Maga)、伪结核棒状杆菌(Corynebacterium pseudotuberculosis, CP)、羊口疮病毒(orf virus, ORFV)、牛支原体(Mycoplasma bovis, Mb)等牛羊常见病原均无交叉反应;敏感性高,最低检测限为5.72 copies·μL^(-1);重复性优,组内变异系数和组间变异系数均小于1.00%。6株Movi分离株Hsp70基因全长均为1 818 bp,与其它Movi参考株核苷酸和氨基酸同源性分别为96.0%~99.4%和98.0%~100.0%;进一步分析发现,山羊源Movi均比绵羊源多1个N-糖基化位点。遗传演化分析表明,其均处于ClusterⅠA亚分支(均为山羊源)。综上,本研究建立了特异性强、敏感性高、重复性优的基于Hsp70基因的Movi的qPCR检测方法。序列分析发现,不同来源Movi的Hsp70基因核苷酸同源性高;遗传演化分析证实,Movi福建株与山羊源分离株遗传关系较近。本研究不仅为Movi临床诊断提供了技术支持,更为进一步了解Movi遗传演化规律提供参考。

基于政策工具的职业教育信息化政策文本演进分析

随着职业教育信息化建设的不断深入,研究我国的职业教育信息化政策文本,对于认清职业教育信息化政策现状,促进其更好的发展十分必要。通过将我国1999—2023年的61份职业教育信息化相关的政策文本放入以政策工具、职业教育信息化构成要素和时间的三维分析框架中进行内容量化分析,得出我国职业教育信息化政策的演进趋势和使用情况。根据信息化政策文本分析,提出未来优化方向,从而为未来政策调整提供参考。

政策工具视角下乡村人才振兴政策文本量化分析

乡村人才振兴是实现农民富裕富足、农村宜居宜业、农业高质高效的基础性战略支撑。基于政策工具视角构建政策工具类型、政策内容指向的二维交叉模型,运用文献计量法和内容分析法,分析我国中央层面发布的73份乡村人才振兴政策文本。分析发现,乡村人才振兴政策主题日益明晰、政策体系日臻完善,但存在政策工具运用失衡、政策导向相对集中、顶层设计协同不足、政策集成效益较弱等问题。后续政策调整应通过优化政策工具运用布局、促进政策导向全面涵容、加强政策体系顶层设计、推进政策集成效益提升等措施,增强乡村人才振兴政策的实际执行绩效,实现乡村人才的兴盛发展。