共查询到20条相似文献,搜索用时 656 毫秒
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多元散射校正对近红外光谱分析定标模型的影响 总被引:20,自引:5,他引:15
采用近红外漫反射光谱分析技术,用傅里叶变换型光谱仪对50个烟叶样品采集吸收光谱,采用常用的多元散射校正(MSC)对光谱预处理,通过主成分分析、相关谱等方法比较分析了预处理对光谱分析的影响,用偏最小二乘(PLS)回归法建立近红外光谱与总糖含量的定标模型,用Leave-One-Out的交叉检验(Cross-Validation)检验定标模型,结果PLS因子数由MSC校正前的5降为校正后的3,RMSECV值仅由0.884 1%降为0.85%。实验证明:对光谱进行MSC预处理能有效减少模型的最佳因子数,简化数学模型,使模型更稳定,更便于传递,但并不能显著减小最优定标模型的预测标准差,即不能显著提高模型的预测能力。 相似文献
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BCEIA‘99金奖产品NIR—2000近红外光谱仪和化学计量学光谱分析软件 总被引:1,自引:0,他引:1
介绍了BCEIA’99金奖产品NIR-2000近红外光谱仪和化学计量学光谱分析软件及其成套技术的主要特点,以及近红外光谱快速分析技术将在我国分析领域中产生一次技术革命的作用 相似文献
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近红外漫反射光谱分析中新的数据处理方法 总被引:1,自引:0,他引:1
本文利用近红外漫反射光谱分析法,在以往工作的基础上,对小麦和大豆的蛋白质含量进行了研究,提出了波长不连续光谱的差分变换方法,并首次在固定滤光片式近红外漫反射光谱仪上应用了这种方式。对小麦和大豆蛋白质含量的实验分析表明:应用这种数据处理方法能极大地减轻分析工作的强度及分析计算的工作量,更加完善了该类仪器的分析计算功能。 相似文献
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近红外光谱和气相色谱-质谱联用技术对橄榄油掺杂及品质分析研究 总被引:1,自引:0,他引:1
分别采用近红外光谱技术及气相色谱-质谱联用技术对橄榄油样品进行分析。采用透射方式采集橄榄油样品的近红外光谱比漫反射方式可以获得更好的重现性;通过直观分析、二阶求导以及主成分分析可快速判别橄榄油与掺杂橄榄油。0.10 g橄榄油样品经过10 mL的KOH-甲醇溶液甲酯化处理后,加入10 mL正己烷和10 mL水进行液液萃取,并对正己烷提取液进行气相色谱-质谱分析,对39种橄榄油脂肪酸甲酯含量的分析结果与近红外光谱的主成分分析图对比得出,油酸和亚油酸是影响橄榄油近红外光谱扫描结果的主要成分。 相似文献
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Although single-photon fluorescence lifetime imaging microscopy (FLIM) is widely used to image molecular processes using a wide range of excitation wavelengths, the captured emission of this technique is confined to the visible spectrum. Here, we explore the feasibility of utilizing near-infrared (NIR) fluorescent molecular probes with emission >700 nm for FLIM of live cells. The confocal microscope is equipped with a 785 nm laser diode, a red-enhanced photomultiplier tube, and a time-correlated single photon counting card. We demonstrate that our system reports the lifetime distributions of NIR fluorescent dyes, cypate and DTTCI, in cells. In cells labelled separately or jointly with these dyes, NIR FLIM successfully distinguishes their lifetimes, providing a method to sort different cell populations. In addition, lifetime distributions of cells co-incubated with these dyes allow estimate of the dyes' relative concentrations in complex cellular microenvironments. With the heightened interest in fluorescence lifetime-based small animal imaging using NIR fluorophores, this technique further serves as a bridge between in vitro spectroscopic characterization of new fluorophore lifetimes and in vivo tissue imaging. 相似文献
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近红外光谱分析仪器的应用与发展 总被引:3,自引:0,他引:3
本文简要介绍了近红外光谱分析仪器的发展简史,技术原理和特点,基本的仪器分类并且按照分类例举了几个知名厂商的仪器,最后探讨了近红外光谱分析仪器的实现方式以及典型用途,为希望了解近红外光谱分析仪器的同仁提供了较为详细的资料。 相似文献
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《Flow Measurement and Instrumentation》2005,16(5):289-293
A novel technique for creating in-line images of black oil/water systems is presented. The technique utilizes the sensitivity of a CCD (Charge Couple Device) in the NIR wavelength region where crude oils are transparent to light. The measuring system consists of a probe, an endoscope, a CCD camera, a strobe light and a PC. A high-pressure in-line instrument based on the technique is presented in detail, and typical resulting images are included. The measuring system has shown that it is possible to create images from black crude oil systems with the use of NIR light, and the technique has been applied in an in-line instrument facilitating observations in high-pressure real hydrocarbon systems. 相似文献