共查询到19条相似文献,搜索用时 62 毫秒
1.
小波变换在重叠化学信号解析中的应用 总被引:1,自引:0,他引:1
将小波变换应用于重叠化学信号的分辨与处理,由于在噪声较大的情况下二阶导数法很难从噪声中区分出微弱信号峰,故通过小波卷积法确定各个组成峰的位置.在信噪比相对较低的情况下明显优于二阶导数法,然后利用小波滤波器处理数据,处理后的峰可达到基线分离,峰位置和面积基本不变.将此方法应用于单一成分的正丁酮、正丁醛以及乙醇、正丙醇、异丙醇、正丁醇、正戊醇和仲辛醇6种醇类物质的混合物处理,得到了满意结果. 相似文献
2.
3.
4.
一种基于二进小波变换的自适应滤波方法 总被引:3,自引:0,他引:3
根据信号和噪声经小波变换后在不同尺度上有不同的特征,将相邻尺度二进小波变换值的相关量进行归一化处理并与小波变换值比较来判断信号与噪声,以噪声在各尺度的方差作为终止迭代的标准,提出了一种基于二进小波变换小波域选择噪声的自适应滤波方法。研究了模拟信号的去噪过程、半峰宽和信噪比对去噪结果的影响,并对模拟含噪信号和含噪毛细管电泳信号去噪前后的结果进行了比较。实验结果表明:由于该方法具有良好的自适应性和显著的滤波效果,必将得到广泛的应用。 相似文献
5.
6.
7.
8.
样条小波和Fourier变换联用技术在分析化学中的应用 总被引:5,自引:1,他引:4
探讨了样条小波和Fourier变换方法的算法及应用特征,将两种方法联合使用,设计出了一种新型的数字滤波器,使两种方法互相取长补短,使各自的优势能得到充分发挥.优选了处理低信噪比分析化学信号的滤波参数.不仅能使结果峰形高度保真,克服样条小波分析方法的不足,而且可对高噪声信号进行处理. 相似文献
9.
首次提出了二阶样条小波卷积分峰法, 通过二阶样条小波与重叠化学信号的卷积运算, 确定出各组分的峰位置和峰宽之比, 再利用样条函数构造峰分辨器, 分辨重叠信号, 同时给出了方法的理论依据, 并对参数的选择进行了讨论. 对大量仿真信号和实验信号的处理实践表明, 分辨后信号可以达到基线分离, 峰位置相对误差小于0.2%, 峰面积相对误差小于4.0%, 即使对于重叠严重的信号, 也能获得满意结果. 该方法可以直接用于含噪音的及多个峰的重叠体系, 是一种分辨重叠信号的有效新方法. 相似文献
10.
毛细管电泳激光诱导荧光检测信号的小波滤噪 总被引:3,自引:0,他引:3
采用小波滤噪方法对毛细管电泳激光诱导荧光检测信号进行了处理,研究了小波变换中小波基的选择及噪声阈值的选择对滤噪的影响。结果表明,采用DB4小波基能有效消除毛细管电泳激光诱导荧光检测信号中存在的噪声,使信噪比得到较大改善。 相似文献
11.
Spline wavelet and orthogonal wavelet are two widely used wavelet methods. In this paper, comparison of these two methodshas been made, including their algorithm, properties and results of signal processing in analytical chemistry signals. It is found that spline wavelet is more effective than orthogonal wavelet in processing high noise signals. The curves obtained from spline wavelet are closer to the theoretical ones than those obtained from orthogonal wavelet and the errors of spline wavelet are smaller than those of orthogonal wavelet. 相似文献
12.
针对基于二进小波变换奇异性检测方法的不足,提出基于连续小波变换奇异性检测方法,该方法具有较细致的局部奇异性刻画能力,能够对滴定曲线的滴定终点进行精确的定位。将这种方法应用于NaOH对HCl和H3PO4滴定曲线滴定终点的确定,取得了理想的结果。 相似文献
13.
Spline wavelet analysis for voltammetric signals 总被引:3,自引:0,他引:3
Application of wavelet multifrequency channel decomposition (WMCD) in electroanalytical chemistry is presented in this paper. A new approach on this digital processing technique, to extract useful information from high noise signals in voltammetry, is described in detail. The method of constructing a model of B-spline WMCD and its application with 2nd, 3rd and 4th order B-spline in the linear scan voltammetry are thoroughly discussed and several results obtained. If the suitable optimal wavelet basis and frequency scale value are selected, the absolute values of the peak relative errors are less than 2% when the signal-to-noise ratio (S/N) is greater than 0.2, and the absolute values of the peak potential relative errors are less than 12% when S/N is greater than 0.3. The processed results of experimental data with high noise are also satisfactory. The whole computation is simple and needs shorter time than other signal processing methods. 相似文献
14.
15.
MengLongLI HuaYiQI FuShengNIE ZhiNingWEN BinKANG 《中国化学快报》2003,14(11):1193-1195
In this paper the embedded zerotree wavelet (EZW) method and Huffinan coding are proposed to compress infrared (IR) spectra. We found that this technique is much better than others in terms of efficiently coding wavelet coefficients because the zerotree quantization is an effective way of exploiting the self-similarities of wavelet coefficients at various resolutions. 相似文献
16.
In the work, a new signal processing algorithm is presented and applied for the transformation of the sigmoidal shaped curves, registered in normal pulse voltammetry (NPV), to the peak shaped curves. The method is based on the continuous wavelet transform (CWT) and specially constructed mother wavelet defined using the ideal wave‐shaped curve. Transformation of the signal, elimination of noises and separation of overlapping data can be achieved in one step by means of proposed procedure. The operation and effectiveness of the algorithm is presented using ideal, noised and overlapping simulated curves. The process of simultaneous determination of lead and indium as well as transformation of curves registered for elements' ions: lead, indium, thallium and cadmium is described. The obtained results show substantial improvement of the performance of NPV. 相似文献
17.
18.
A new way of analyzing current oscillations that accompany anodic metal dissolution is presented. A wavelet transformation is used for separation and spectral analysis of singular courses—elementary components of electrochemical oscillation recordings. A method of obtaining oscillation energy distribution analogous to the spectral power density function is presented. It is shown that the chaotic component (Shil'nikov chaos) can be separated from the deterministic component of the described process. 相似文献
19.
为了实现对工业气体SO2的浓度进行监控,基于紫外差分吸收光谱法开发了SO2在线检测系统。针对系统噪声和Mie散射使吸收光谱叠加带来的误差,本文提出采用小波变换降噪技术代替传统光谱处理方法中的多项式平滑滤波技术来提高检测精度。通过对应用了Symlets、Daubechies、Coiflet和Biorthogonal这4种不同小波函数的实验数据分析和对传统小波阈值选取方式的改进,最终确定了基于rigisure阈值的小波阈值去噪的信号处理方法,并提出一种新的信噪比量来衡量信号处理的效果。这种方法可以快速可靠地处理光谱信号,处理后所得的监测浓度准确度基本控制在1.5%以内。在实验室环境下和工业现场环境下的大量实验结果表明本方法能有效的减小噪声对SO2浓度监测带来的影响。 相似文献