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1.
现代仪器在胆结石研究中的运用   总被引:1,自引:0,他引:1  
对胆结石组分和元素进行准确的分析可为治疗胆结石和预防其复发提供重要的参考。文章综述了现代仪器在胆结石研究中运用的研究进展,这些技术包括拉曼光谱、能谱(EDX)、傅里叶红外光谱(FTIR)及其二阶导数谱、热重分析(TG)、差示扫描量热法(DSC)、原子吸收光谱、电感耦合等离子发射光谱、高效液相色谱(HPLC)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等。  相似文献   

2.
光机系统分析方法   总被引:1,自引:1,他引:0       下载免费PDF全文
李福  阮萍  马小龙  赵葆常 《应用光学》2006,27(6):497-501
为了使光学仪器能在恶劣的环境下正常工作,需要对其进行详尽的工程分析。对光机系统的分析方法,包括传统分析方法、集成分析方法和统一分析方法进行了研究,说明了它们的工作原理及实现的具体步骤,分别列举了它们的优缺点。进一步指出在集成分析中热弹性分析需要解决的问题及Zernike多项式拟合中需要注意的问题,归纳了使用统一分析方法时需要特别注意的问题。在比较了3种方法优缺点的基础上,对光机分析方法进行了展望,得出集成分析方法在很长一段时间内将是光机系统分析的主要方法的结论。  相似文献   

3.
基于无机元素的含量判别食醋的种类和品牌方法研究   总被引:5,自引:0,他引:5  
化学计量学广泛应用于食品种类和原产地的区分。文章采用原子吸收法测定了32个食醋样品中的Mg, K, Pb, Zn, Fe, Mn, Ca和Cu等八种无机元素含量。采用向量相似法计算了陈醋和白醋以及同一种类不同品牌食醋的相似度;通过聚类分析和主成分分析对来自北京、江西、江苏和山西4个地区品牌的食醋进行了分类,对不同种类的食醋(陈醋和白醋)也进行了分类。聚类分析和主成分分析都将食醋样品分为两大类,每个大类又将食醋样品按不同品牌分开。食醋中无机元素含量差异可作为食醋种类和品牌判别的测量指标之一。  相似文献   

4.
A power law classification scheme (PLCS) of time series correlations is proposed. It is shown that PLCS provides the ability to classify nonlinear correlations and measure their stability. PLCS has been applied to gross domestic product (GDP) per capita of G20 members and their correlations analysed. It has been shown that the method does not only recognise linear correlations properly, but also allows to point out converging time series as well as to distinguish nonlinear correlations. PLCS is capable of crash recognition as it is shown in the Argentina example. Finally the strength of correlations and the stability of correlation matrices have been used to construct a minimum spanning tree (MST). The results were compared with those based on the ultrametric distance (UD). Comparing the structures of MST, UD and PLCS indicates that the latter one is more complicated, but better fits the expected economic relations within the G20.  相似文献   

5.
Abstract

Fourier transform infrared spectroscopy (FTIR) is a fast and nondestructive analytical method. Associated with chemometrics, it is a powerful tool for the pharmaceutical industry. It is becoming a suitable technique for analysis of herbal medicine. This review focuses on the recent developments and updates for the qualitative and quantitative analysis of herbal medicine using FTIR. Moreover, it can be implemented during herbal drug development, in production for process monitoring, or in quality control laboratories.  相似文献   

6.
Radhakrishnan Nagarajan   《Physica A》2006,370(2):355-363
Scaling analysis of the magnitude series (volatile series) has been proposed recently to identify possible non-linear/multifractal signatures in the given data [Y. Ashkenazy, et al. Phys. Rev. Lett. 86 (2001) 1900; Y. Ashkenazy, et al. Physica A 323 (2003) 19; T. Kalisky, Y. Ashkenazy, S. Havlin. Phys. Rev. E 72 (2005) 011913]. In this article, correlations of volatile series generated from stationary first-order linear feedback process with Gaussian and non-Gaussian innovations are investigated. While volatile correlations corresponding to Gaussian innovations exhibited uncorrelated behavior across all time scales, those of non-Gaussian innovations showed significant deviation from uncorrelated behavior even at large time scales. The results presented raise the intriguing question whether non-Gaussian innovations can be sufficient to realize long-range volatile correlations.  相似文献   

7.
Abstract: Forensic examination and dating documents is an important issue in our society, because documents are used throughout our lives to record everything we do. It starts with our birth certificate and ends with our death certificate. Between them there are receipts, leases, deeds, contracts, checks, wills, sales agreements, and medical records. The validity of all of these documents is often questioned during litigation. This study describes the use of nondestructive analysis of paper (Fourier transform infrared [FTIR] spectroscopy using an attenuated total reflectance [ATR] technique, Raman spectroscopy) and destructive analysis of paper (microscopic analysis of fibers, FTIR analysis of paper ash, inductively coupled plasma–mass spectrometry [ICP-MS]). The results are discussed in detail.  相似文献   

8.
煤结构是各类煤相关研究的微观基础,光谱分析作为煤结构研究的重要方法被广泛应用,其在煤结构研究中的进展对光谱分析方法的普及、应用和发展有重要意义。光谱分析方法研究煤结构已成为煤化工领域使用的常规方法,能够快速无损检测,对煤分子结构的破坏小,可为不同环境条件下煤物理化学性质的变化提供有效的检测手段。从光谱分析在煤质、大分子结构、煤中元素三个方面介绍光谱分析方法,主要对傅里叶变换红外光谱(FTIR)、Raman光谱分析、核磁共振谱(NMR)进行综述介绍,阐明其在煤结构研究中的发展历史、应用的关键研究结果及其意义。综合国内外煤结构研究中的多种光谱分析方法及应用现状发现:目前研究并没有彻底解决煤结构特征及性质变化的问题,缺乏对煤结构光谱特征信息共性的总结,未能形成煤中官能团和元素的不同光谱信息数据库,存在光谱特征峰与煤结构信息不对等的问题,即在某波长存在特征峰但无法与煤中官能团匹配,或煤官能团受元素组成、键能等影响对多波长产生响应的问题。现阶段对原煤自然状态下结构的研究已经不能满足煤应用中产生的问题,单一的光谱分析方法不能全面分析煤结构特征,且对影响煤结构光谱特征变化因素的研究较少,尤其是煤样的前处理和煤在萃取等过程中,前处理液和萃取剂对煤光谱特征的影响。展望光谱分析在煤结构的研究中可以从以下几方面入手:光谱分析与其他方法的联用以综合描述煤结构,如化学方法、高分辨率透射电镜(HRTEM)、扫描轨道显微镜(STM)、质谱(MS)等方法的联用,定性、定量全面分析煤结构特征;多种条件下煤结构及光谱特征,现阶段应利用光谱分析方法研究煤在多种条件下的结构特征及性质变化,解决煤在实际应用中的问题。如对煤进行氧化、氢化、热解、燃烧、低温、液化、汽化等处理,分析过程变化和产物特征,有助于推测母体煤的结构,了解煤的性质,控制煤物理化学过程变化中的产物,获取煤的精细化学品;煤光谱分析特征信息库建立,网络大数据背景下建立煤光谱分析特征信息库及可视化数据查询平台,实现多条件模拟假设,演示和探索煤结构在不同条件下的动态变化,利用人工智能、云计算方法实现煤各类光谱数据的处理分析,增强光谱数据信息挖掘,提升数据有效性和实用性。  相似文献   

9.
介绍了小波分析和神经网络方法在核物理及核工程领域的应用现状。 分别对小波分析及神经网络方法的基本原理进行了介绍, 详细讨论了小波变换中的多分辨分析方法在γ能谱平滑以及核电站设备监测等方面的应用, 讨论了连续小波变换在γ能谱分析、 粒子种类鉴别以及核反应堆安全监测等领域的应用。 同时, 还详细介绍了神经网络方法在以上各领域的发展现状。 最后, 展望了两种方法在核安全检测、 核辐射防护以及核电站实时监控等领域的发展趋势。 Applications of wavelet analysis and neutral networks in the field of nuclear physics and engineering are reviewed. The principle of these two methods are introduced briefly, and then the applications of multiresolution analysis technique in the smoothing of γ ray spectroscopy, and in nuclear power plant monitoring are discussed in detail. Applications of the continuous wavelet analysis method in γ ray spectroscopy analysis, in particle identification , and in nuclear reactor safety monitoring are also talked over. In addition, the applications of neutral networks in above fields are introduced. Finally, the trends of the future development for these two methods are prospected.  相似文献   

10.
Surface analysis by ToF-SIMS analysis of ballpoint pen ink markings was performed for discrimination. ToF-SIMS provided non-destructive analysis of ink's organic and inorganic components directly off paper with no interference from the paper substrate. Organic and inorganic information were collected simultaneously and processed with PCA, discriminating 41 out of 45 pairs (91%) of pens analysed. Minimal sample preparation and analysis time, the simultaneous acquisition of organics and metals, and ability to analyse trace amounts gives this technique advantages over others currently utilised in the forensic field. Simultaneous acquisition of organics and inorganics has not been presented before for the characterisation of these materials. It was indicated that pens from the same manufacturer, but discrete batches, can be significantly different.  相似文献   

11.
Covariant helicity amplitude analysis for the process of J/ψ→γPP is discussed starting from the Smatrix elements of decay process,we deduce the formulae of helicity coupling amplitudes for two-body decay process,These formulae are used to analyze intermediate resonance states in the process of J/ψ decay to γππ,γKK,γηη′  相似文献   

12.
基于子空间分析的人脸识别方法研究   总被引:3,自引:0,他引:3  
人脸识别技术是模式识别和机器视觉领域的一个重要研究方向,在众多人脸识别的算法中,基于子空间分析的特征提取方法以其稳定可靠的识别效果成为了人脸识别中特征提取的主流方法之一。本文对目前应用较多的子空间分析方法进行了研究,具体介绍了线性子空间分析方法:主成分分析(PCA)、线性鉴别分析(LDA)、独立主成分分析(ICA)、快速主成分分析(FastICA)等及非线性子空间分析方法:基于核的PCA (KPCA)等的基本思想及其在人脸识别中的研究进展,包括一些新的研究成果。此外,还应用orl及Yale B人脸库对几个基础的子空间方法进行了验证实验。实验结果表明,在几个子空间分析方法中,FastICA算法取得了最高的识别率。最后结合实验结果对各算法的优缺点进行了分析总结。  相似文献   

13.
基于ANSYS的红外光学系统的有限元分析   总被引:1,自引:1,他引:0  
红外光学系统作为空-空导弹的重要有机组成部分,要经历复杂的动力学环境。采用有限元分析方法对红外光学系统结构在工作状态下的变形、应力及固有频率进行了全面分析。验证了光学系统的结构是否满足光学像质要求和刚度要求,确定了面形变化的显著区域,并专门对其中的关键结构进行了详细分析,进而提出结构优化的途径。该方法对光学系统结构设计和分析具有现实意义,有助于进一步分析研究光学系统结构动力学。  相似文献   

14.
为探讨一种快速、及时对水上油膜种类进行鉴别的方法,采用水上油膜反射率光谱数据结合聚类分析方法、主成分分析方法和小波变换分别对厚度为300,500和1 000 μm的煤油,300,1 000和1 500 μm的润滑油,50,300和500 μm的轻柴油和500,2 000 μm的180#柴油等四种常见溢油油种进行判别研究。聚类分析结果表明:采用欧氏距离计算样本间的聚类距离,在距离L=8.976以上能够将样本正确分类,准确率100%;对同一油种油膜而言,油膜厚度接近的更易聚类;主成分分析结果表明:对原始数据、小波概要系数和小波细节系数分别进行主成分分析,其中小波细节系数对油种区分效果最佳,四种油膜样品在主成分得分空间中独立分布。利用反射率光谱数据结合聚类分析和基于小波细节系数的主成分分析对水上油膜种类的鉴别是可行的。  相似文献   

15.
《光谱学快报》2013,46(5):527-536
A Fourier transform infrared (FT-IR) spectrometric method diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was developed for the rapid, direct measurement of mebendazole in drugs. Conventional KBr-spectra and DRIFTS-spectra were compared for best determination of active substance in drug formulations. Two chemometric approaches, partial least-squares (PLS2) and principal component regression (PCR+) methods were used in data procesing. The best results were obtained with the PLS2 method.  相似文献   

16.
It is important to develop and to practically use the method to analyze a micro-nanometer order area. Especially, three-dimensional microanalysis for minute structure that consists of the organic compounds and the polymer is difficult. We developed a novel three-dimensional microanalysis method by means of focused ion beam (FIB) for section processing and ToF-SIMS for mapping method. For the purpose of realization of three-dimensional microanalysis and a chemical and structural analysis of the organic matter, the sensitivity improvement of ToF-SIMS in the three-dimensional analysis device and the method of the spectral analysis are examined. To improve the sensitivity of ToF-SIMS, the sample stage was modified to arrange perpendicularly with the ToF optical axis, and the distortion of electric field was corrected. And, by analyzing the fragment ions by using the principal component analysis (PCA) to raise the efficiency of the spectrum analysis, spatial resolution has improved. As a result, the resolution of the device improved to sub micrometer order, and advanced to the achievement of the three-dimensional microanalysis.  相似文献   

17.
因子分析在红外光谱法中的应用   总被引:2,自引:1,他引:1  
因子分析是一种多元统计的分析方法。本文着重介绍因子分析在红外光谱分析研究中的应用。  相似文献   

18.
红外小目标检测技术由于其重要的军事意义成为研究热点。根据目标、噪声和背景边缘在小波域的不同特点,提出一种基于小波分析的红外小目标检测算法。该算法利用小波对奇异信号强有力的分析能力,消除了噪声和背景边缘对小目标检测的干扰,实现目标的检出。仿真实验证明该方法对红外图像中的小目标有比较理想的检测效果。  相似文献   

19.
利用密度泛函理论对于HIO3分子的异构化及其消去反应势能面进行了细致的研究.B3LYP结合混合基组,对于O和H原子使用6-311 G(3df,3pd)基组,对于I原子使用3-21G基组,进行结构优化,振动频率计算以及电子拓扑学分析.在势能面上八个稳定的异构体结构被找到,经过计算稳定性如下:HOIO2-1>HOOOI-2>HOOOI-1>HOIOO-1>HOIOO-2>HOIO2-2>HIO3-1>HIO3-2,此外,势能面上存在三种稳定的松散复合物.对于势能面上IO HO2,OIO OH和IOO OH的反应机理进行了详细的讨论.利用振动模式分析的方法对于反应物,中间体,过渡态以及产物之间的关系进行明确的分析.此外,还应用电子密度拓扑学对于异构化及其消去过程进行分析.  相似文献   

20.
现代仪器在泌尿系结石元素分析中的运用   总被引:2,自引:0,他引:2  
对泌尿系结石所含元素进行准确的分析可为治疗尿石症和预防其复发提供重要的参考,文章综述了现代仪器分析技术在泌尿系结石元素分析中的运用及其研究进展,这些技术包括:X射线光电子能谱(XPS)、质子激发X射线发射光谱(PIXE)、能量分散X射线分析(EDX)、电子束探针微区分析(EPMA)、原子发射光谱(AES)、原子吸收光谱(AAS)、电感耦合高频等离子体发射光谱(ICP)、X射线荧光光谱(XRF)及离子选择性电极等。  相似文献   

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