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1.
将近红外漫反射光谱技术应用到血糖无创监测中,实验使用傅里叶近红外光谱仪及其光纤附件采集志愿者指尖的近红外漫反射光谱。并对光谱进行平滑,基线校正和一次求导预处理,采用偏最小二乘法建立校正模型。采集漫反射光谱的同时抽适量的血样在分光计上标定血糖的实际值,并对校正模型计算值和实际标定值进行比较,结果表明个体建模的相关性很好,相关系数达到0.891以上,均方差小于0.122。  相似文献   

2.
可见/近红外光谱的南丰蜜桔可溶性固形物含量定量分析   总被引:9,自引:3,他引:6  
基于可见/近红外漫反射光谱定量分析技术对南丰蜜桔的可溶性固形物含量进行实验研究.采用偏最小二乘法对南丰蜜桔完整果和果肉的可见/近红外光谱进行了分析,并且比较和讨论了不同光谱预处理的建模结果.实验结果表明:在波长范围350~1800nm,一阶微分光谱所建模型效果最佳.其中完整果所建校正模型的预测相关系数为0.825和预测均方根偏差为0.899;果肉所建校正模型的预测相关系数为0.893,预测均方根偏差为0.749.  相似文献   

3.
为解决传统有创检测血糖的问题,文中对近红外光谱无创血糖检测技术进行了研究。使用ABB公司的TALYS ASP531近红外光谱仪测得葡萄糖溶液的光谱,建模波段选取5 500~6 500 cm -1,使用偏最小二乘法建立光谱数据与对应浓度之间的校正模型。实验结果表明,校正模型的决定系数达到了0.983 99,校正均方根偏差为1.023 26 mmol·L -1,误差分布为-1.3~1.7 mmol·L -1,证明了近红外无创检测人体血糖浓度的可行性,为近红外血糖检测的研究提供了可靠的依据。  相似文献   

4.
近红外光谱法对同仁乌鸡白凤丸的定性和定量分析   总被引:9,自引:1,他引:8  
采用近红外漫反射光谱分析技术对同仁乌鸡白凤丸进行定性和定量分析.采集了98份同仁乌鸡白凤丸和58份不同厂家乌鸡白凤丸样品的近红外漫反射光谱.采用判别分析法对同仁乌鸡白凤丸和乌鸡白凤丸进行鉴别.以70份同仁乌鸡白凤丸的近红外光谱为标准,建立相似度匹配模型,并将其用于计算其余样品的相似度.采用偏最小二乘回归法建立了同仁乌鸡白凤丸总氨基酸、芍药苷、水分含量的定量分析模型,对未知样品进行含量预测.结果判别分析模型的错判数为0.相似度匹配模型能正确区分同仁乌鸡白凤丸和乌鸡白凤丸.校正模型的相关系数分别为0.9614,0.9651,0.9910,验证集均方差分别为0.199%,0.00436%,0.386%.本方法准确可靠,操作简便,快速无损,可推广用于工业现场的原位检测.  相似文献   

5.
基于近红外光谱的花椒麻味物质快速检测方法   总被引:7,自引:0,他引:7  
针对传统方法测定花椒麻味物质含量耗时、费工的缺点,提出了应用近红外光谱分析技术,快速检测花椒麻味物质含量的新方法.对于141份粉碎到40目的花椒粉末样品,首先使用基于主成分得分与遗传算法的近红外光谱建模样品选择方法(PCA-SSGA)进行样品选择,优选出80份样品.然后应用偏最小二乘法(PLS),将其中60份样品的近红外光谱建立校正模型,并对其余20份样品组成的预测集进行预测.结果显示,测定系数(R220)为0.9004,预测标准差(RMSEP20)为0.8130,预测相对标准差(RSD20)为6.07%,预测相对分析误差(RPD20)为3.1670.说明模型对预测集样品具有一定的预测能力,基于近红外光谱技术快速检测花椒麻味物质是可行的.  相似文献   

6.
为了提高可见-近红外(Vis-NIR)光谱法检测水质pH值的精度和稳定性,基于连续投影算法(SPA)和粒子群优化-最小二乘支持向量机(PSO-LSSVM)建立了多元校正模型。采集60个不同pH值水溶液样品的Vis-NIR光谱数据,运用Savitzky-Golay卷积平滑和标准正态变量变换对原始光谱数据进行预处理。基于SPA筛选的特征波长和PSO算法自动优化LSSVM的建模参数,建立多元非线性校正模型。结果表明,相比于其他对比模型,SPA-PSO-LSSVM模型具有更高的精度与更优的稳定性,验证集的均方根误差为0.67、决定系数为0.91,剩余预测偏差为3.10。  相似文献   

7.
应用近红外光谱分析技术结合化学计量学方法,建立了奶粉脂肪和蛋白质含量测定的化学计量学建模新方法.首先采用Kernard-Stone法对校正集样本和预测集样本进行分类,然后利用小波变换滤波技术对样品的近红外光谱进行压缩去噪处理,结合滤波后重构光谱信号建立脂肪和蛋白质的径向基神经网络回归模型,并分别对径向基网络的扩散常数spread值及小波变换中的小波基与压缩尺度三个参数进行了详细的讨论.脂肪模型在小波基为db2及小波尺度为4、spread值为3.5时的预测模型精度最好;蛋白质模型在小波基为db8及小波尺度为4、spread值为6时,预测模型精度最好.所建立的脂肪和蛋白质校正模型的预测集相关系数(Rp)分别为0.990和0.994,预测均方根误差分别为0.007与0.004.预测结果表明,RBF网络结合小波变换进行建模预测,模型简单、稳健且精度较好,该方法适合奶粉脂肪和蛋白质含量的快速、无损测定.  相似文献   

8.
通过建立校正集样本不同的模型Ⅰ与模型Ⅱ来研究温度对水泥生料近红外光谱模型的影响,其中模型Ⅰ中的建模样本为温度一致的样本,模型Ⅱ中的建模样本为温度变化的样本,建模方法采用偏最小二乘法。对比两组模型的预测结果可知,模型Ⅱ中SiO_2、Al_2O_3、Fe_2O_3、CaCO_3的预测方均根误差与模型Ⅰ相比分别减小了78.3%、26.4%、42.9%、60.4%。实验结果表明:温度变化会导致预测结果产生一定的误差。在校正集中加入温度不同的样本进行建模,可以降低预测误差,使近红外光谱模型更好地应用于生产现场。  相似文献   

9.
采用近红外光谱技术结合反向传播人工神经网络算法建立了茶叶中蔗糖含量的检测模型,并通过引入遗传算法改进了模型预测质量.预测模型采用120个茶叶掺蔗糖样品的傅里叶变换漫反射光谱数据建立.对另外42个样品的预测结果表明,基于传统的反向传播人工神经网络算法模型的相关系数为0.738 0,预测均方根误差为3.075 4,正确识别率为83.3%;增加遗传算法后相关系数提高到0.941 9,预测均方根误差为1.3176,正确率为88.1%,训练误差减小一个量级以上.实验结果表明,反向传播人工神经网络模型可用来检测茶叶中的蔗糖含量,同时,引入遗传算法优化了神经网络的初始权值和阈值,使预测误差更小.  相似文献   

10.
用近红外光谱数据建立相思树综纤维素含量数学模型   总被引:1,自引:0,他引:1  
刘胜  张文杰 《红外》2010,31(5):37-40
用近红外光谱数据建立了相思树综纤维素含量的预测模型.首先对近红外光谱数据进行预处理并按波长进行分组,然后使用拟合方法建立许多非线性子数学模型,最后通过计算加权平均值给出预测综纤维素含量的公式.模型预测值的平均相对误差为0.0074,预测误差明显小于用近红外光谱仪所带软件建立的模型的预测误差.文中的建模方法有望用于相思树其它成分的预测.  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

13.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

14.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

17.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

18.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

19.
This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.  相似文献   

20.
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.  相似文献   

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