不同类别白菜傅立叶变换红外光谱判别研究

[目的]利用傅立叶变换红外光谱（FTIR）技术对不同类别的白菜进行判别区分分析.[方法]将不同类别的白菜打浆处理,经冷冻真空干燥后结合FTIR技术对白菜溴化钾压片扫描,对中红外光谱数据进行DA聚类判别分析,并对模拟甲醛白菜样品做预测判别分析.[结果]试验得出,30个普通白菜、78个绿色白菜及30个模拟甲醛处理白菜建模样品能有效地聚类分布在不同区域;预测4个模拟甲醛处理的白菜样品都能准确判别分布在甲醛白菜范围内,准确率超过95％.[结论]利用FTIR技术结合光谱数据的DA判别分析,能较准确地对普通白菜、绿色白菜、模拟甲醛处理白菜进行区分分析,并对抽样验证甲醛白菜的类别进行准确预测判别.     

秋季黄海底层鱼类群落结构的变化

根据1985年和2000年秋季渔业生物资源底拖网调查资料，分析了黄海底层鱼类群落结构的时空变化。结果表明，渔业资源优势种的组成随区域和时间不同有着较大的差异。黄海北部和中部渔获种类组成相似性较高，北部与南部、中部与南部的相似性较低；黄海渔获生物种类组成年间相似性较高，为65。进一步的单因子ANOSIM分析表明黄海底层鱼类群落不同区域和年间种类组成没有显著性差异。黄海渔业生物多样性由北向南递减。与1985年相比，2000年鱼类群落长度谱表现出小型种类和小个体增多，大个体减少，且长度范围变小；主要优势种的长度组成也呈现小型化趋势。长度谱区域变化则是从北部向南部小个体数量增多，大个体数量减少。     

基于近红外漫反射光谱的多品种桃可溶性固形物的无损检测

【目的】研究基于近红外漫反射光谱的多品种桃可溶性固形物含量的无损检测技术。【方法】在获得3个不同品种桃近红外漫反射光谱的基础上,采用多元散射校正(MSC)方法处理原始光谱,以SPXY算法划分样品集,分别建立了可溶性固形物含量的偏最小二乘回归(PLSR)、极限学习机(ELM)和最小二乘支持向量机(LSSVM)预测模型,并比较和评价了移动窗口偏最小二乘法(MWPLS)和连续投影算法(SPA)优选有效特征波长对于简化模型运算量、改善模型预测性能的影响。【结果】虽然全光谱可以获得较好的识别效果,但是模型比较复杂;MWPLS与SPA优选的有效特征波长均能有效地减少建模变量并简化模型,但MWPLS在提高建模效率和改善模型预测精度方面有更明显的优势;PLSR、ELM与LSSVM模型都取得了较理想的预测结果,其中PLSR方法较适用于全光谱建模分析;MWPLS-ELM模型对样品集中桃可溶性固形物含量的预测性能最好,其校正相关系数、校正均方根误差、预测相关系数和预测均方根误差分别为0.991,0.397,0.983和0.497。【结论】近红外漫反射技术可用于多品种桃可溶性固形物含量的准确、无损检测,也为其他品种果品的内部品质指标快速、无损检测提供了技术借鉴。     

花生壳与花生壳生物炭对镉离子吸附性能研究

将花生壳(PS)改性制备成花生壳生物炭(PSB),研究了吸附时间(10~5760min)、吸附剂用量(0.1~5g)、镉离子溶液初始pH值(1~8)和浓度(10~800 mg·L-1)等因素对Cd2+去除效率的影响;利用场发射扫描电镜(SEM)、傅里叶红外光谱(FTIR)与模型拟合分析,探讨了PS和PSB的吸附性能与机理。实验结果表明,PS和PSB是优良的生物质基吸附材料;pH为5.0、Cd2+溶液浓度为10mg·L-1、吸附剂添加量为4 mg·mL-1时,PS的去除效率为93.33%,PSB的去除效率为99.51%;吸附容量分别可达26.88 mg·g-1、28.99mg·g-1;Freundlich与Langmuir吸附模型均能较好地描述PS和PSB对Cd2+的等温吸附过程,以Freundlich模型略优。SEM电镜扫描和FTIR图谱分析表明PS和PSB对镉的吸附主要为多分子层的表层络合吸附:SEM分析表明PS和PSB在吸附Cd2+以后表面具有大量的颗粒附着物;FTIR分析表明PS与PSB吸附镉的主要机理为络合反应,PS参与络合反应的主要官能团为-CHO、-C=O、-OH和-P=O,PSB参与络合反应的主要官能团为-C=C-、-C≡C-、-C≡N和-OH等官能团。     

长白山森林下垫面湍流谱特征研究

利用2003年5月27日、28日在长白山原始森林冠层2个不同高度上观测的湍流资料,采用通量处理软件Eddypro计算和分析了森林冠层上、下的湍流谱结构和局地各向同性特征。结果表明:在惯性副区内,归一化湍流谱遵循-2/3的指数规律;在冠层上、下,大气湍流并不是各向同性的;而在冠层内则是近似各向同性的;基本说明了在森林冠层内,物质和能量是以小涡形式输送的。从冠层下和冠层上的风速分量和温度谱的峰值频率比较可以得出冠层下的湍涡尺度要相对较小的结论。     

Fluorescence Spectra and Lifetime from Sodium Dodecyl Sulfate

Sodium dodecyl sulfate(SDS) is often used to reinforce the fluorescence of some materials,which need to know the fluorescence from SDS.A steady fluorescence spectrometer was used to analyze the SDS solution with different concentrations.The fluorescence spectra covers longer wavelength scope in ultraviolet light region.The position of the first fluorescence peak ranges from 290 nm to 300 nm with red shift with increase of concentration and fixes at 300 nm as reaching critical micelle concentration.Hereafter,bimodality appears at 300 nm and 330 nm.The first fluorescence peak should derive from the excited oxygen atom between carbon and sulfur.The excited oxygen atom,bonding with sulfur,should generate the peak at 330 nm is traversed.At the same time,fluorescence lifetime of various concentrations SDS.Fitting routine is applied to decay curve and calculates average fluorescence lifetime.The average fluorescence lifetime of SDS becomes long while concentration increasing,and the lifetime at 330 nm is longer than that at 300 nm.     

IN SITU SPECTROELECTROCEMISTRY AND ITS APPLICATIONS ON CONVENTIONAL FT-IR SPECTROMETER

In situ spectroelectrochemistry on a conventional FT-IR spectrometer and its applications in the following fields are briefly described: electrochemical reactions in solution, the determinations of formal potential ( E01 ) and electron transfer number ( n ) , chemically modified electrode film, the oxidation, corrosion and inhibition on metal surface.     

Application and Progress in Cancer Analysis by FTIR Spectroscopy

The research progress and the application of FTIR spectroscopy on diagnosing cancer are reviewed. The cancer is one of the tallest diseases of the rate of human beings. At present, its diagnosis primarily depends on the pathology one. The process of pathology diagnosis is bother and often suffers the influence of the artificial factors. Along with the rapid development of FTIR spectroscopy and its correlative technique, the FTIR spectroscopy has been applied not only to studying the structure of big biologic molecules like protein or nucleic acid, but also to studying more and more complicated system like cells and tissues. The research expresses that FTIR spectroscopy can open out the characteristics of tissues of cancer from the molecular level, and it is very possible that FTIR will be a quantitative instrument of diagnosing cancer.     

不同品种油菜籽仁的傅里叶变换红外光谱鉴别

用傅里叶变换红外光谱法测试了9个油菜品种的45个油菜籽仁样品的光谱。光谱显示,油菜籽仁的主要成分是油脂、蛋白质和碳水化合物等。对各品种油菜籽仁的平均光谱差异和吸光度比A1657/A1054和A1576/A1512进行比较,发现它们可用于区分不同品种的油菜籽仁。对1 700～1 600 cm-1范围的二阶导数光谱进行分析,发现各品种的振动谱带差异明显,可用以区分不同品种的油菜籽仁。研究表明,傅里叶变换红外光谱法结合二阶导数光谱,可以鉴别不同品种的油菜籽,具有方便、快捷的特点。     

Durability,reaction to fire properties,and environmental impact of treated and untreated wooden claddings

Abstract

This work summarizes the output of durability, reaction to fire properties, and environmental impact of wooden claddings subjected to treatments modified with TiO₂ and clay nanoparticles. The objective was to investigate the effects of 1 wt% of TiO₂ and clay nanoparticles in existing water-based and stain coatings and preservatives regarding the properties mentioned above. Water vapor resistance properties were used to assess the moisture transfer properties of the specimens by using the cup test. The reactions to fire properties of the specimens were analyzed using small-scale cone calorimeter test. Accelerated aging was used to study the weathering properties of specimens, where the performance of the specimens with aging was characterized using Fourier transform infrared (FTIR) analysis. The effect of increasing the percentage of nanoparticles from 1 wt% to 3 wt% on the weathering properties of the specimens was further analyzed. Moreover, comparison between the overall environmental impact between unmodified water-based paint and water-based paint modified with 1 wt% of TiO₂ nanoparticles was performed using available environmental data and weathering test results as analyzed by FTIR.