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1.
本文将一维卷积法与奇异值渐进图(SVEP)法相结合用于重叠色谱峰的分辨。试验结果表明:利用卷积技术的识别效应,再结合SVEP法,能较好地分辨出混合体系中的各组分信息,并得出相应的选择性区间,这种集成技术不失为一种分辨重叠色谱峰的有效方法之一。  相似文献   

2.
将多元曲线分辨-交替最小二乘(MCR-ALS)与高效液相色谱-二极管阵列检测器(HPLC-DAD)检测相结合,对伊立替康、7-乙基-10-羟基喜树碱和喜树碱的色谱重叠峰进行分辨。采用MCR-ALS同时分析多个数据矩阵组成的方式,以克服MCR-ALS在单一重叠峰数据矩阵的解析中遇到的缺秩问题。讨论了影响分辨结果的几种因素,包括被分析物之间的光谱相似度、色谱峰的分离度和干扰物浓度等。分辨所得光谱还原率高,定量结果可靠,说明MCR-ALS能有效地解决喜树碱及其衍生物色谱分析中重叠峰的二阶校正问题。  相似文献   

3.
将新近发展的非负矩阵因子分解法(NMF)与最小二乘相结合,提出一套对手性药物重叠峰的HPLC-DAD二维数据作化学波谱分辨和定量分析的方法。因无选择性检测波长,手性药物的重叠组分无法分别检测。本文首先应用NMF实现重叠峰的光谱色谱分辨,在此基础上,结合最小二乘拟合,实现了对重叠组分的同时定量。对实测体系手性药物盐酸舍曲林及顺式对映体重叠峰的分析.证明该解析方法与传统的垂直分割法相比,可获得更令人满意的结果,回收率在95.5-104.5%,符合仪器分析的要求。该方法在手性药物未完全分离的情况下,可获知在混合体系中手性药物及对映体量的多少,对手性药物进一步分离纯化有指导作用。表明化学计量学方法与现代分析手段有机结合,为手性药物等复杂体系的分析提供新途径。  相似文献   

4.
色谱法测定乙苯和二甲苯时,各组分色谱峰相互重叠而影响测定结果。本文用高效液相色谱联用二极管阵列检测器(HPLC-DAD)测定乙苯和二甲苯,采集7.20-8.53min,205-235nm范围内的二维色谱数据,再用直观推导式演进特征投影法(HELP)和交替最小二乘法(ALS)计算,依靠乙苯、二甲苯各异构体之间紫外吸收光谱的微小差异,解析它们的重叠色谱峰。各组分浓度在1-50μg/mL,浓度比为1∶10范围内的分辨结果令人满意,分辨下限为0.2μg/mL,该法成功地用于大气环境中乙苯和二甲苯异构体的测定。结果表明:HELP结合ALS适用于解析色谱严重重叠的多组分体系。  相似文献   

5.
盲信号分离算法处理色谱重叠峰   总被引:3,自引:2,他引:1  
盲信号分离算法可以实现重叠化学信号分离。在色谱分析中对盲信号分离命题进行解释,提出独立成分分析的独立成分对应分离的单位色谱峰,混合矩阵的元素对应各组分含量的单位比值。构造两组分的模拟色谱重叠峰作为计算验证,测定正己烷/正庚烷混合体系的色谱重叠峰作为实验验证。经过模拟和实验验证,对色谱分析中的重叠峰,进行各组分比例不同的多次测定,测定次数大于或等于组分数目,采用信号盲分离算法可以求出各组分的单位色谱峰,并确定重叠峰内各组分的相对含量。  相似文献   

6.
用化学计量学方法分析小兴安岭7种松科植物松叶挥发油气相色谱-质谱(GC-MS)数据,为松叶挥发油的药理活性与其它的应用研究提供依据。(1)用直观推导式演进特征投影(heuristic evolving latent projections,HELP)法分辨重叠色谱峰,得各组分的纯色谱峰和质谱;(2)用正交投影法比较不同挥发油的GC-MS数据;(3)用峰面积归一化法确定各化合物的相对含量;(4)用主要化学成分进行聚类分析。7种松叶挥发油的化学成分为单萜、倍半萜及其衍生物和酯类化合物,按化学成分7种松叶挥发油可分为3类。  相似文献   

7.
代谢物的定性定量分析,是进一步探讨不同生理病理状态下的代谢物差异变化的基础,也是寻找生物标记物及其代谢通路的前提条件。但目前在对代谢产物GC-MS数据的分析中,重叠峰的解析却成为其分析的难题,重叠峰的存在使得色谱图无法直接进行定性和定量分析。对于重叠色谱峰,采用一般的色谱分析处理方法,大都耗时耗力,而随着计算技术的发展,各种新的方法不断被应用到代谢产物重叠峰的处理中。本文采用熵最小算法,对丙酮丁醇梭菌胞内代谢产物经硅烷化衍生后的GC-MS数据进行分析,对其中的几组重叠色谱峰进行重建分析,得到其所包含的纯组分,并对各组分分别进行定性和定量分析。结果表明,针对代谢产物复杂体系中的重叠色谱峰,采用熵最小方法能够比较全面的得到重叠信号中的各个组分的信息,并能成功地对其进行定性定量处理。  相似文献   

8.
用于重叠峰分辨的卡尔曼滤波法   总被引:1,自引:1,他引:0  
导数法广泛应用于重叠峰分辨,但信噪比会随着导数阶数的增加而降低。提出一种基于卡尔曼滤波的导数方法,可以显著提高高阶导数谱的信噪比,提高重叠峰分辨力。另外,该方法不需要建立数学模型,计算简便,能满足手持式仪器实时性要求。用仿真数据研究了该法在重叠峰分辨中对信噪比的影响,以离子迁移率谱图分辨为例说明了该法的实际应用。  相似文献   

9.
应用化学计量学方法对卷烟的主流烟气粒相物中极性非挥发物硅烷衍生化的CC-MS数据进行了解析。首先应用主成分分析法判断各色谱峰中的化学成分数。对于其中含有多种成分的重叠峰,应用多变量曲线分辨-变换最小二乘法(MCR- ALS)进行解析。用最大不相关法选取MCR-ALS的一组初始迭代矢量。最后根据总离子流图对解析得到的色谱峰曲线进行标度化。对选定样品的GC-MS数据进行判别,发现17%的色谱峰是2种或3种成分的重叠峰,经过解析可得到较好的色谱图和质谱图。结果表明了此方法在复杂样品的GC-MS数据解析中的有效性。  相似文献   

10.
本文采用了样条卷积(SC)的方法用以分辨重叠峰,通过这个方法考察了有机氯类农药DDT中的2个同分异构体P.P‘-DDD和O.P‘-DDT气相色谱重叠峰,结果表明信号峰的分辨率由处理前的0.840提高到处理后的1.496。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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