Overlapped peaks resolution for linear sweep polarography using Gaussian-like distribution

A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn（Ⅱ） and Co（Ⅱ）, coexisting in the leaching solution of zinc hydrometallurgy. A Gaussian-like distribution was constructed as the sub-model of overlapped peaks by analyzing the characteristics of linear sweep polarographic curve. Then, the abscissas of each peak and trough were pinpointed through multi-resolution wavelet decomposition, the curve and its derivative curves were fitted by using nonlinear weighted least squares （NWLS）. Finally, overlapped peaks were resolved into independent sub-peaks based on fitted reconstruction parameters. The experimental results show that the relative error of half-wave potential pinpointed by multi-resolution wavelet decomposition is less than 1% and the accuracy of Ip fitted by NWLS is higher than 96%. The proposed resolution method is effective for overlapped linear sweep polarographic peaks of Zn（Ⅱ） and Co（Ⅱ）.

Methods for obtaining characteristic γ-ray net peak count from interlaced overlap peak in HPGe γ-ray spectrometer system

For a characteristic c-ray with interlaced overlap peak, and the case where its reliable and credible net count cannot be obtained using the current high-purity germanium(HPGe) multichannel γ-ray spectrum software, two new methods are proposed herein to obtain the γ-ray net peak count from the interlaced overlap peak in the HPGe cray spectrometer system, of which one is the symmetric conversion method based on Gaussian distribution and the other is where the energy average value of two close γ-rays is regarded as the γ-ray energy. The experimental results indicate that the two methods mentioned above are reliable and credible. This study is significant for the development of better γ-ray spectrum processing software for measuring complex γ-ray spectra concerning the nuclear reaction cross section, neutron activation analysis, and analysis of transuranium elements, using an HPGe detector.

A New Method to Resolve Overlapped Voltammetric Peaks

A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper. The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this method, and satisfactory results were obtained. The results show excellent correlation between peak areas of the processed signals and the concentrations.

Separating Overlapped Peaks of SF6 Decomposed Products Based on Iterative Curve-fitting Method

The SF6 decomposed products are very alike,so the peaks of the SF6 decomposed products are overlapped.It make us hard to quantitatively calculate.This paper introduced a method to separate the overlapped chromatogram peaks with iterative curve-fitting and Gauss function,and deduced the formula of the iterative curve-fitting;provided a method to calculate the initial value of the peaks intensity and width by iterative formula,and confirm the final peaks intensity and width to separate the overlapped signals.By the analysis of the real chromatogram data,it proved the validity of this method on the main components used in distinguishing the GIS internal defects.This method overcomes the influence of SF6 peak to the other thin concentration peaks,so it can be used in the study of the quantitative analysis of the decomposed products on different failures and different voltages.

X射线光电子能谱(XPS)谱图的分峰拟合

X射线光电子能谱(XPS)分峰拟合是数据结果后处理的常用技术,实际工作中,缺乏XPS分析工作经验的使用者对分峰拟合结果不确定性大。为尽量提高结果的确定度,XPS分峰处理时,需要对样品采集的XPS谱峰进行必要的分析判断、选择正确拟合模型、合理的参量值或范围、选用适当的谱峰背景扣除方法等。在简述分峰拟合基本理论的基础上,通过列举O 1s的自重叠、C 1s与Ru 3d相互重叠、N 1s与GaLM俄歇峰群重叠的分峰典型案例,由浅入深,分析评估了拟合参量对拟合结果的影响,探索分峰拟合技术,努力提高XPS分峰结果确定性。

A correlation OPTS algorithm for reducing peak to average power ratio of FBMC-OQAM systems

A correlation overlapping partial transmit sequence(C-OPTS) algorithm is proposed to solve the issue of high complexity of overlapping partial transmit sequence(OPTS) algorithm in suppressing the peak to average power ratio(PAPR) of filter bank multicarrier-offset quadrature amplitude modulation(FBMC-OQAM) signals.The V subblocks in partial transmit sequence(PTS) are regrouped into U combinations according to the correlation coefficient p,and overlapping subblocks are allowed between adjacent groups.The search starts from the first group and sets the phase factors of the subsequent groups to 1.When the phase factors of the non-overlapping subblocks in the first group are determined,the subsequent groups are searched in turn to determine their respective phase factors.Starting from the second data block,the data overlapped with it should be taken into account when determining its optimal phase factor vector.Theoretical analysis and simulation results indicate that compared with the OPTS algorithm,the proposed algorithm can significantly reduce the computational complexity at the cost of slight deterioration of PAPR performance.Meanwhile,compared with the even-odd iterative double-layers OPTS(ID-OPTS) algorithm,it can further reduce the complexity and obtain a better PAPR suppression effect.

基于能量色散XRF光谱的土壤重金属As与Pb同时定量分析方法

针对能量色散XRF光谱难以实现土壤重金属Pb与As的同时准确定量检测问题,基于Pb元素Lα、Lβ及As元素Kα、Kβ的谱峰特性,提出了一种能量色散XRF光谱土壤重金属As与Pb同时定量分析方法。该方法通过构建不同浓度Pb元素Lα与Lβ特征峰强度关系,根据实测样品Pb元素Lα与As元素Kα重叠峰强度信息,准确解析Pb元素Lα及As元素Kα特征峰强度,基于已建立的定量分析曲线实现土壤样品中Pb与As的准确反演。通过对不同浓度Pb与As共存土壤样品定量检测,相比ICP-MS测量结果,本文方法对20.25~844.84mg·kg-1重金属Pb检测的相对误差在0.86%~11.09%之间,平均相对误差为6.17%;对26.99~825.93mg·kg-1重金属As检测的相对误差在0.10%~14.72%之间,平均相对误差为8.11%,实现了Pb与As共存土壤中Pb与As含量的同时准确定量分析,为发展土壤重金属现场快速XRF精准检测设备提供了方法。

基于非洲秃鹫算法优化卷积神经网络的重叠峰解析方法

利用光谱仪器检测土壤中重金属时,由于仪器分辨率较低,峰位相近元素的特征峰会产生重叠。光谱重叠峰严重影响定量分析结果的准确性,为了得到准确的重金属含量需要进行光谱重叠峰分解。提出利用非洲秃鹫算法优化卷积神经网络(AVOA-CNN)的重叠峰解析方法。首先,利用高斯函数模型模拟出150个双高斯含噪光谱重叠峰和43个三高斯含噪光谱重叠峰,选择不同小波基函数进行光谱数据去噪,以信噪比和均方根误差(root mean square error, RMSE)为评价指标,最终确定coif 3小波基函数,使用导数法进行光谱重叠峰预处理。然后,使用AVOA-CNN获得卷积神经网络(convolutional neural network, CNN)预测结果,解析结果表明:AVOA-CNN成功分解重叠峰且准确率高,双高斯光谱重叠峰和三高斯光谱重叠峰参数(峰强度,峰位,峰宽)的最大相对误差平均值分别为3.15%和5.90%。最后对比麻雀搜索算法优化CNN、CNN与AVOA-CNN,结果显示AVOA-CNN模型预测准确率最高。

Resolution method for overlapping peaks based on the fractional-order differential

Equations between the differential order and the maximum of the fractional-order differential for the specified peak signals are developed based on the variation of the maximum of the specified peak signals at different orders. Also, equations between the differential order and the zero-crossing of the fractional-order differential of the specified peak signals are proposed according to the variation of the zero-crossing of the specified peak signals at different orders. Characteristic paramters of the Gaus- sian peak, Lorentzian peak, and Tsallis peak can be estimated using estimator I and estimator II which are obtained by the equations above. As a result, a new method is presented to resolve the overlapped peaks signal. Firstly, a fractional-order differential of the specified peak signals is obtained with the fractional-order differentiation filter. Then, characteristic paramters of the specified peak signals can be extracted using estimator I and estimator II. Finally, the Tsallis peak is used as a model to assign the overlapping peak signals correctly. Experimental results show that the proposed method is efficient and effective for the simulated overlapping peaks and detected overlapping voltammetric peak signals.

基于Voigt函数拟合的能量色散X射线荧光光谱(EDXRF)法测定金矿粉末中低品位金

为了提高金矿粉末含金量检测的准确性和安全性,以金矿粉末为研究对象,运用能量色散X射线荧光光谱法(EDXRF)对金矿粉末进行检测,利用Voigt函数拟合分离出金元素的Lα纯元素特征峰,分析测定金矿粉末中金的含量。在实验中,发现金的Lα峰与锌的Kβ峰存在明显重叠,为了排除锌元素的干扰,引入降噪技术和Voigt函数进行分峰处理,利用纯锌和纯金的标准溶液配制符合金矿粉末样品中锌金四种比例的混合溶液,通过滤波和降噪算法处理得到相对纯净的重叠峰,加入Voigt函数拟合分离锌和金的重叠峰,得到金的Lα峰净强度值,通过纯金和纯锌标准溶液建立回归线得到金矿粉末中金的真实含量,对比金矿粉末的参考含量数据,偏差度皆小于10%,含量大于3 g/t以上偏差值则小于2%,结合EDXRF法对检测样品无损伤的特点,提高了金矿中金含量检测的安全性、准确性和可靠性。

Spline wavelet in the resolution of overlapping voltammetric peaks

Spline wavelet transform is used to resolve overlapping voltammetric peaks. A suitable resolving factor is chosen to multiply the filters of spline wavelet and make it a peak resoluter. Simulated overlapping voltammetric peaks are processed by the peak resoluter and satisfactory results are obtained. Base-line separation can be achieved, the relative errors of peak position are less than 3.0%, and the relative errors of peak area are less than 5.0%. The effect of different resolving factors and spline wavelet basis are discussed. To test the procedure, two systems, cadmium (II)-indium (III) and lead (II)-thallium (I), are used.

恶臭气相色谱信号的分类算法研究

工业化的快速发展带来了恶臭污染问题,而现有的恶臭气相色谱仪(gas chromatography, GC)面临着因算力分配不均而导致的效率低下的问题。通过对恶臭气相色谱信号进行分类并分派给为每种峰形定制的解析算法可以使算力分配得以优化。文中致力于恶臭气相色谱信号分类算法的研究,着重进行了恶臭气相色谱信号的处理,并对比了K最近邻(K-nearest neighbor, KNN)、支持向量机(support vector machines, SVM)、随机森林(random forest, RF)3种分类算法的性能。首先对信号进行预处理,提取了特征点并计算特征参数,以特征参数为分类依据代入算法程序并检验算法的准确率,以此来评价每种算法的性能。实验结果显示RF算法拥有较好的应用效果和发展潜力。该文可为实现算力的均衡分配提供一些参考依据。

二维相关光谱和导数光谱色谱图法识别及解混高效液相色谱二极管阵列色谱峰

基于高效液相色谱-二极管阵列检测器(HPLC-DAD)获得的色谱-光谱数据,建立了一种二元完全重叠液相色谱峰的快速解析定量方法:将HPLC-DAD采集的时间t、波长λ、吸光度S的三维光谱色谱数据,光谱经过背景补偿加Savitzky-Golay平滑预处理,得到光谱波长方向的吸光度强度处理值随时间变化的光谱图,与对照品光谱计算光谱相似度,实现重叠峰的快速智能化识别;利用导数光谱色谱图法对预处理的色谱-光谱矩阵进行解析,获得原点波长,再利用二维相关光谱技术提取特征光谱后,得到基于特征光谱的原点波长的色谱流出曲线,进而得到分离后的色谱峰,实现重叠色谱峰的定量测定。该方法充分利用HPLC-DAD获得的三维色谱-光谱数据信息,能够将二元完全重叠色谱峰有效解析分离和定量测定,明显提高解析结果的准确度,并利用色谱工作站实现了数据采集、解析识别、定量分析一体化智能分析,方法简单高效。

小波变换用于色谱重叠峰的解析

利用小波变换的时频局部化性质，通过对色谱重叠峰信号小波变换后的某些频率段 进行放大，使重叠谱峰得到了分离，并将此方法用于苯和甲苯二组分色谱体系的定量分析，重 叠峰中各组分均得到了良好的线性关系及令人满意的定量分析结果。本文还讨论了不同小 波基、分解的次数及放大系数对解析结果的影响。

基于峭度的重叠峰解析新方法

峭度是表征曲线陡峭程度的物理量。本实验提出了基于峭度的组分分析 (componentanalysisbasedonkurtosis,CABK)方法来解析重叠峰 ,从中分离出纯组分信息。这种新方法的优点在于半盲源分离 ,即只要判断出重叠峰所含组分的数目 ,就可从混合谱中分离出各组分的纯谱信息。将它用来解析模拟两组分重叠峰体系和酒样的GC MS混合谱 。

光谱重叠峰的曲线拟合解析策略与实现

针对光谱分析中的重叠峰问题,提出了一种基于曲线拟合的光谱重叠峰解析算法,讨论了曲线拟合的参数调整和表达非唯一性等问题,提出了最小峰-峰间距(MRI)、可分离最小峰-峰间距(MSI)和拟合误差曲线的三个特征区间等概念;在峰位的确定中,引入由宽逐严的排除策略。含噪模拟光谱重叠峰解析结果表明,所提出的算法是有效的。

二维色谱/光谱重叠峰的定性定量方法研究(I)——水中多种酚二维色谱/光谱重叠峰的分辨与定性定量

探讨了ＨＥＬＰ法在水中酚类色谱重叠峰的分辨与定性定量分析中的应用．实验结果表明，各组分浓度比为１∶５０的范围内分辨光谱与真实光谱十分吻合．在１０－４～１０－６ｇ／ｍＬ的浓度范围内分辨色谱的定量结果线性关系良好．分辨下限３．０×１０－７ｇ／ｍＬ，相对标准偏差为５．０％．

紫外-可见吸收光谱结合高斯多峰拟合技术测定甲基红酸离解常数(英文)

在一定pH值范围内,甲基红(MR)水溶液紫外-可见吸收光谱特征是酸式甲基红(HMR)最大吸收峰((530±15)nm)与碱式甲基红(MR-)最大吸收峰((435±20)nm)叠合在一起.本文用高斯多峰拟合技术实现了HMR和MR-叠合峰的分峰拟合计算.拟合计算输出两个吸收峰的积分面积即峰强度A1和A2,A1和A2之比与MR-和HMR浓度之比.进而计算甲基红水溶液酸离解平衡常数pKa.用本方法测量298.15K时的pKa值为4.76.拟合优度高,拟合度R2、拟合优度χ2分别达到0.998和10-5以下.深入探讨了表面活性剂十二烷基硫酸钠(SDS)、十六烷基三甲基溴化铵(CTAB)聚集行为对甲基红pKa的影响.与传统分光光度测量方法相比,紫外-可见吸收光谱结合高斯多峰拟合技术结果更可靠,测量步骤和数据处理过程更简单,更具有普适性.

多重谱峰的分解方法

利用高斯混合模型(GMM)良好的逼近能力对能谱进行精确描述,并从统计学角度采用期望最大化(EM)迭代算法以4个重叠的伽马谱峰为例,进行了重叠峰的分解。该方法可对由更多谱峰叠加的重叠峰进行分解,并能保证较小的统计误差,对放射性核素的定量和定性分析具有较大参考价值。

离子色谱重叠色谱峰的处理

介绍通过信号微分处理分辨离子色谱中重叠峰的方法。实验将对Ｆ－、Ｃｌ－、Ａｃ－、ＮＯ２－、ＮＯ３－、ＰｈＣＯＯ－、山梨酸根和葡萄糖酸根等常见离子分组按一定比例混合，对重叠峰进行微分处理，得到的微分谱图可由峰高定量，收到了较好的效果。