小波变换用于近红外光谱性质分析

以汽油研究法辛烷值分析为例,研究了小波变换在近红外光谱分析中的应用。对近红外光谱的小波特性、小波变换参数以及变量提取方法进行了详细研究。研究结果表明：光谱噪音、有用信息和背景分别分布在小波高、中和低频区域;母小波函数对性质分析结果影响很大;小波变换可以同时扣除光谱背景、去除噪音和压缩变量,具有运算速度快、分析精度高以及无需去噪后处理等优点,在近红外光谱分析中具有很好的应用前景。     

基于近红外光谱技术的内燃机油鉴别研究

针对常规近红外光谱技术测试内燃机油时光谱信号响应低,对大分子基团分辨率不高,以及光谱信息与其结构组成之间存在非线性关系等难点,提出了一种基于电压为外扰方式的内燃机油二维近红外光谱测试技术,介绍了近红外光谱具有分形的特征.运用小波变换将近红外光谱分解至不同分辨尺度,然后计算各尺度分量的分形维数(盒维数),用近红外光谱的小波基分形参量替代近红外光谱的采样值.计算结果表明,在不同小波基和不同分解尺度下,内燃机油近红外光谱具有不同的盒维数,得到了近红外光谱在分形意义下的特征信息.以美孚、埃索和壳牌3种内燃机油品种鉴别分类问题为实例,比较研究了近红外光谱采样值与小波基分形参量,K近邻法的交互验证计算结果表明,小波基分形参量的分类效果优于近红外光谱采样值.采用近红外光谱技术测试内燃机油的结构组成信息是可行的.     

褶合光谱法作抗脱氧核糖酸突变药物筛选的初步研究

采用褶合光谱法考察紫外线致脱氧核糖核酸（DNA）突变,并以褶合光谱差谱值δ的形式量化地表达DNA细微突变的程度,其灵敏度远高于二附导数光谱法。DNA中添加二甲亚砜后表现的褶合光谱差谱变化与高效毛细管电泳指纹图谱的结果一致。褶合光谱法分析过程简单快速,可以用于抗紫外线损伤、抗突变药物的初步筛选。     

褶合光谱法作抗脱氧核糖核酸突变药物筛选的初步研究[ HS)

采用褶合光谱法考察紫外线致脱氧核糖核酸(DNA)突变,并以褶合光谱差谱值δ的形式量化地表达DNA细微突变的程度,其灵敏度远高于二阶导数光谱法.DNA中添加二甲亚砜后表现的褶合光谱差谱变化与高效毛细管电泳指纹图谱的结果一致.褶合光谱法分析过程简单快速,可以用于抗紫外线损伤、抗突变药物的初步筛选.     

小波变换结合多维偏最小二乘方法用于近红外光谱定量分析

将小波变换和多维偏最小二乘法相结合用于近红外光谱定量校正模型的建立。首先将原始光谱进行小波变换分解，得到系列小波细节系数，通过选取一组受外界因素少、信息强的小波系数组成三维光谱阵，然后再采用多维偏最小二乘法建立校正模型。实验结果表明，该方法所建近红外校正模捌的预测能力更强，并更具稳健性。     

拉曼光谱在固相有机合成中的应用

本文综述了近几年以来拉曼光谱在固相有机合成中的应用研究进展，分别介绍了近红外傅立叶变换和共焦显微两种拉曼光谱技术。近红外傅立叶变换拉曼光谱克服了荧光背景带来的干扰，可以用在固载试剂、催化剂的表征、固相有机反应的监测等方面，特别对于在无机载体上进行的有机反应的表征和检测方面具有很大的优势。共焦显微拉曼光谱具有特殊的空间分辨能力，适合对固相合成载体的结构进行表征，并可对载体内部反应活性位点的分布情况进行研究。     

近红外光谱法快速测定聚乙烯醇的醇解度

应用傅里叶变换近红外漫反射光谱技术,通过对光谱预处理方法的选择和模型优化,建立了准确度较好的聚乙烯醇醇解度近红外定量分析模型,并验证了其可行性。通过验证试验表明,其预测值接近于化学法测定值,适合聚乙烯醇醇解度快速测定。     

一种基于近红外光谱技术的茶叶非法添加物鉴别方法

本发明公开了一种基于近红外光谱技术的茶叶非法添加物鉴别方法。本方法应用傅里叶变换近红外漫反射光谱分析技术结合因子法建立定性分析模型;应用傅里叶变换近红外漫反射光谱分析技术结合偏最小二乘法(PLS)建立定量分析模型,以两个模型结合应用实现茶叶中非法添加物(蔗糖、糖浆和米糊)的快速准确鉴别。本方法具有分析速度快、效率高、成本低、测试重现性好、样品无需预处理且便于在线无损检测的特点。     

褶合曲线分析法用于同步荧光光谱法同时测定苯酚和对苯二酚

采用计算机辅助褶合曲线分析法结合同步荧光光谱法对双组分体系（苯酚／对苯二酚、苯酚／邻苯二酚）同时测定。苯酚和对苯二酚的荧光光谱重叠比较严重，同步荧光光谱虽使选择性有所改善，但仍有重叠，苯酚和对苯二酚的同步荧光峰相差仅２０ｎｍ。褶合曲线分析法可很好地用来测定苯酚和对苯二酚，方法简便、准确、易于自动化，同时证明，褶合曲线分析法在荧光分析方面具有很好的应用前景。进一步试验苯酚和邻苯二酚双组分的同时测定，苯酚和邻苯二酚的同步荧光峰相差仅１０ｎｍ，结果表明，该法虽然能在苯酚存在的情况下测定邻苯二酚，但不能同时测定苯酚。     

傅立叶变换近红外光谱法快速评价涪陵榨菜品质

应用傅立叶变换近红外光谱技术,建立了评价涪陵榨菜品质的定量分析模型.测定了58份涪陵榨菜的近红外光谱数据,通过光谱预处理方法消除噪声,以偏最小二乘法(PLS)建立回归模型.最终得到评价其品质的水分、总酸(以乳酸计)和氨基酸含量近红外光谱分析模型的决定系数(R2)依次为0.957 8、0.975 4、0.950 4,交叉...     

Structure analysis of aromatic medicines containing nitrogen using near-infrared spectroscopy and generalized two-dimensional correlation spectroscopy

Four aromatic medicines (acetaminophen; niacinamide; p-aminophenol; nicotinic acid) containing nitrogen were investigated by FT-NIR (Fourier transform near-infrared) spectroscopy and generalized two-dimensional (2D) correlation spectroscopy. The FT-NIR spectra were measured over a temperature range of 30-130 degrees C. By combining near-infrared spectroscopy, generalized 2D correlation spectroscopy and references, the molecular structures (especially the hydrogen bond related with nitrogen) were analyzed and the NIR band assignments were performed. The results will be helpful to the understanding of aromatic medicines containing nitrogen and the utility of these substances.     

扑热息痛片剂药品的近红外光谱法非破坏定量分析

现代近红外光谱分析技术将近红外光谱 (NIR)法同计算机科学和化学计量学结合 ,实现了对样品进行无损非破坏性定量分析 .该法具有速度快、操作简单及所需样品少等特点 ,能够实现样品分析的时间同步、地点同步及无损非破坏分析 .为实现生产过程中即时、在线的质量控制提供了新的手段[1 ] .本文应用人工神经网络 [2 ]与近红外漫反射光谱相结合对扑热息痛片剂药品进行了非破坏快速定量分析 .用扑热息痛片剂药品的近红外漫反射光谱数据、一阶导数光谱数据及二阶导数光谱数据分别建立了 ANN模型 ,预测未知样品 ,讨论了影响网络的因素 ,使用了新…     

Authentication of Dendrobium Species Using Near-Infrared and Ultraviolet–Visible Spectroscopy with Chemometrics and Data Fusion

Herbal products produced from multiple plants have special characteristics in the clinical practice of traditional Chinese medicine. These traits provide the opportunity for fraudulent merchants to mix other herbal products similar in appearance into authentic herbal medicine. Shihu is a tonic herbal medicine from the Dendrobium plants with complex botanical origins. In this context, 11 Dendrobium plants including 109 individuals from China were collected for authentication work. Nine species have been described as herbal medicines in the literature while D. hookerianum and D. xichouense are not reported to have medicinal benefits. A key feature of this study was that multiple recognition approaches, based on near-infrared and ultraviolet–visible spectra as well as their combination, were compared to investigate their classification performance. Intuitively, score plots using principal component analysis and hierarchical cluster diagrams were used to evaluate the genetic relationships among these species. Compared with support vector machine discrimination analysis and k-nearest neighbor models, the partial least square discrimination analysis model combined with low-level data fusion provided excellent performance for authentication and was the most robust model with 100% accuracy rates for the training and prediction sets. The results indicated that near-infrared and ultraviolet–visible spectra and their fusion dataset combined with supervised recognition analysis are effective and therefore recommended for the authentication of genuine and sham of herbal Shihu species.     

Study on difference between epidermis, phloem and xylem of Radix Ginseng with near-infrared and infrared spectroscopy coupled with principal component analysis

Ginseng is a precious traditional Chinese herbal medicine. Different parts of ginseng are deemed to have different medicinal values and properties. Rapid and non-destructive methods, such as diffuse reflectance near-infrared spectroscopy (DR-NIR), Fourier transform infrared spectroscopy with attenuated total reflectance (ATR-FTIR), were used to evaluate the differences of epidermis, phloem and xylem in ginseng, respectively. Samples were grounded into 200-mesh fine powder or cut into slices with about 2 mm thickness for DR-NIR and ATR-FTIR spectra measurement, respectively. To explore the classifications between different parts of ginseng, the spectra of DR-NIR and ATR-FTIR were pretreated to calculate first derivative and then was analyzed with principal component analysis (PCA). The PCA results of DR-NIR spectra indicate that epidermis and xylem part of ginseng have distinct difference, and even different positions of epidermis or xylem part show regular and gradual differences. ATR-FTIR spectra directly show that three parts of ginseng are different at 2920, 2852, 1736 and 925.7 cm⁻¹ peaks, especially for epidermis of ginseng. The PCA results of ATR-FTIR spectra yield clear classifications of the three parts of ginseng.     

Biofunctional magnetic nanoparticles as a general agent to immobilize proteins contained in traditional Chinese medicines

Maghemite nanoparticles were synthesized by the coprecipitation method. Silica was coated to the maghemite nanoparticles and amino silane was modified to the surface of the silica magnetic nanoparticles. We use the biofunctional magnetic nanoparticles as a general agent to immobilize and separate the proteins in a broad range from different traditional Chinese medicines. The transmission electron microscopy results showed that the average diameter of the well-dispersed silica-coated nanoparticles was about 60 nm. The Fourier transform infrared spectrum indicated that the amino group had been successfully coupled to the surface of the maghemite particles. And the protein immobilization effect was characterized by the microplate reader. The characterization results proved that the synthesized functional magnetic nanoparticles could effectively immobilize and separate the proteins from traditional Chinese medicines.     

有机质谱学在蛇床子素、厚朴酚、和厚朴酚与鱼腥草素结构确定中的应用

有机质谱学在中药药效物质的结构确定中起到了至关重要的作用. 对中药药效物质质谱的确切解释需要对这些药效物质质谱的关键裂解规律有足够的了解. 应用有机质谱学规律对中药药效物质的结构确定进行了讨论. 这些中药的药效物质包括: 应用超临界二氧化碳从蛇床子中提取的蛇床子素和从厚朴中提取的厚朴酚与和厚朴酚; 应用水蒸汽蒸馏从鱼腥草中提取的鱼腥草素等. 具有较高丰度的质谱关键碎片峰 m/z 229 的出现是蛇床子素质谱的典型特征; 质谱关键碎片峰 m/z 169 的出现是鱼腥草素质谱的典型特征. 而质谱关键碎片峰 m/z 247 是否出现则是区分厚朴酚与和厚朴酚的质谱典型特征. 在此基础上, 尝试构建中药药效物质的有机质谱学平台.     

微量元素研究对中药研究和应用的指导作用

通过对微量元素与中药材的栽培，中药的炮制加工，中成药的工艺研究及中药的合理应用之间相关性的综述，阐明了微量元素研究对中药研究和应用的指导意义，同时也给研究人员对微量元素的研究提出了新课题。     

Multi‐component determination and chemometric analysis of Paris polyphylla by ultra high performance liquid chromatography with photodiode array detection

Multi‐source analysis of traditional Chinese medicine is key to ensuring its safety and efficacy. Compared with traditional experimental differentiation, chemometric analysis is a simpler strategy to identify traditional Chinese medicines. Multi‐component analysis plays an increasingly vital role in the quality control of traditional Chinese medicines. A novel strategy, based on chemometric analysis and quantitative analysis of multiple components, was proposed to easily and effectively control the quality of traditional Chinese medicines such as Chonglou. Ultra high performance liquid chromatography was more convenient and efficient. Five species of Chonglou were distinguished by chemometric analysis and nine saponins, including Chonglou saponins I, II, V, VI, VII, D, and H, as well as dioscin and gracillin, were determined in 18 min. The method is feasible and credible, and enables to improve quality control of traditional Chinese medicines and natural products.     

中药分析新思路及其质量控制

随着国家对中药现代化的重视,为了更好地诠释中药药性的本质,研究者从不同角度对中药进行研究。分析化学、药学、生物学等多学科的多种不同的技术在这里融合,一些新的思路和方法正在不断涌现,中药的分析与质量控制正沿着综合且全面的方向在不断地发展和前进。该文对当前中药分析新思路及其质量控制进行了简要评述,在此基础上,对中药质量控制的色谱指纹图谱进行了分类说明与研究,表明采用现代分析手段,可以实现对中药质量的有效控制。     

补益中药的抗癌作用与有机锗

有机锗广泛存在于某些中药中，某些补益中药所含有机锗对抗癌有积极意义，为人们辨病选药提供了相应依据，用补益中益治疗肝癌收到良好效果。重点讨论了补益中药所含有机锗的抗癌作用机理。