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R. J. Henry 《Journal of the Institute of Brewing》1985,91(6):393-396
A scanning near-infrared reflectance spectrophotometer was calibrated for the prediction of barley aleurone colour and malt moisture. The malt moisture was predicted on malt ground for the determination of malt extract (coarse grind) making the method suitable for moisture correction in malt extract estimation. Calibrations for the prediction of malt extract and endosperm modification from barley and malt were also attempted. A correlation (r= 0.851 n = 135) was found between malt hot water extract and the percentage of the endosperm estimated as being modified by microscopy following staining with Calcofluor. Probably because of this influence of modification on malt extract, the use of near-infrared reflectance to predict malt extract was most successful at predicting the malt extract values obtained following micro-malting in the absence of the additives, gibberellic acid and potassium bromate. 相似文献
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Igor V. Kovalenko Glen R. Rippke Charles R. Hurburgh 《Journal of the American Oil Chemists' Society》2006,83(5):421-427
A key element of successful development of new soybean cultivars is availability of inexpensive and rapid methods for measurement
of FA in seeds. Published research demonstrated applicability of NIR spectroscopy for FA profiling in oilseeds. The objectives
of this study were to investigate the applicability of NIR spectroscopy for measurement of FA in whole soybeans and compare
performance of calibration methods. Equations were developed using partial least squares (PLS), artificial neural networks
(ANN), and support vector machines (SVM) regression methods. Validation results demonstrated that (i) equations for total
saturates had the highest predictive ability (r
2=0.91–0.94) and were usable for quality assurance applications, (ii) palmitic acid models (r
2=0.80–0.84) were usable for certain research applications, and (iii) equations for stearic (r
2=0.49–0.68), oleic (r
2=0.76–0.81), linoleic (r
2=0.73–0.76), and linolenic (r
2=0.67–0.74) acids could be used for sample screening. The SVM models produced significantly more accurate predictions than
those developed with PLS. ANN calibrations were not different from the other two methods. Reduction in the number of calibration
samples reduced predictive ability of all equations. The rate of performance degradation of SVM models with sample reduction
was the lowest. 相似文献
6.
针对HgGdTe探测器均匀性差、无效像元多,过多无效像元会降低碳卫星CO2探测仪红外焦平面探测器探测精度,提出了一种基于探测器性能测试数据进行无效像元筛选的方法.首先利用CO2探测仪冷光学实验设备采集暗背景数据与响应度数据,然后计算暗背景数据的DN值均值与标准差、各个像元的响应度曲线,利用直方图阈值筛选出暗像元、亮像元、不稳定像元、平均拟合偏差较大等无效像元,最终利用各种无效像元集合交并集确定最终无效像元.结果表明:基于各种无效像元集合交并集确定最终无效像元的无效像元筛选方法准确度更高.通过遍历筛选出无效像元的响应值,从而确认了无效像元筛选的合理性. 相似文献
7.
血氧超慢信号与脑神经递质的超慢振荡特点具有平行性与同源性。应用940 nm单波长近红外对管,检测识别耳颞穴的透射信息,可以帮助理解脑神经血管耦合的机制,同时发现新信号的特征以支持脑认知研究。具体工作包括:①基于输出能量的最大值寻优探头传感角度;②基于软件SPSS11.0统计描述谎实数据差异显著性的P分数;③利用Agilent54624A型示波器内嵌的FFT功能,提取近红外透射信息中0~100 mHz的超低频特征,以便显示谎和实的差异性。研究工作进一步细化了专用的近红外耳穴信息识别系统,为整机的SoC化奠定了基础。 相似文献
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采用熔融淬火技术制备了0.2 mol% Er2O3、1 mo l% Yb2O3、0.1 mol% Tm2O3和x mol% Pr6O11( x=0.25、 0.3、0.35和0.4)掺杂的65TeO2-15ZnO-10Na2O-10WO3系碲酸盐玻璃,通过X 射线衍射(X-ray diffraction,XRD)、差热扫描曲线(differential scanning calorimetry,DSC)对玻璃样 品的抗析晶性和热稳定性 进行了表征。结果表明,玻璃样品具备良好的抗析晶性,析晶温度和转变温度差值为140 ℃,具有较好 的热稳定性。吸收光谱结果显示,Er3+/Yb3+/Tm3+/Pr3+共掺碲 酸盐玻璃在980 nm处有较强的吸收峰,故可 以采用980 nm泵浦源对该玻璃样品进行激发。在1 200—2 000 nm近 红外波段范围,玻璃样品存在峰值中 心为1.35 μm、1.53 μm和1.8 μm 3个波段发射峰,且3个发射峰的荧光半高宽(full width at half maxima, FWHM)均大于100 nm,其覆盖了光信号传输的E、S、C和C+L 4个波段,大幅度地提高了掺铒 光纤放大器(erbium doped fiber amplifier,EDFA)的放大带宽。 相似文献
9.
Zou Rui Huang Junjian Shi Junpeng Huang Lin Zhang Xuejie Wong Ka-Leung Zhang Hongwu Jin Dayong Wang Jing Su Qiang 《Nano Research》2017,10(6):2070-2082
Near-infrared (NIR) persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging.The next key roadblock is to establish a robust and controllable method for synthesizing monodisperse nanoparticles with high luminescence brightness and long persistent duration.Herein,we report a synthesis strategy involving the coating/etching of the SiO2 shell to obtain a new class of small NIR highly persistent luminescent ZnGa2O4∶Cr3+,Sn4+ (ZGOCS) nanoparticles.The optimized ZGOCS nanoparticles have an excellent size distribution of ~15 nm without any agglomeration and an NIR persistent luminescence that is enhanced by a factor of 13.5,owing to the key role of the SiO2 shell in preventing nanoparticle agglomeration after annealing.The ZGOCS nanoparticles have a signal-to-noise ratio ~3 times higher than that of previously reported ZnGa2O4∶Cr3+ (ZGC-1) nanoparticles as an NIR persistent-luminescence probe for in vivo bioimaging.Moreover,the persistent-luminescence signal from the ZGOCS nanoparticles can be repeatedly re-charged in situ with external excitation by a white lightemitting diode;thus,the nanoparticles are suitable for long-term in vivo imaging applications.Our study suggests an improved strategy for fabricating novel high-performance optical nanoparticles with good biocompatibility. 相似文献
10.
以青铜(bronze)粉与Sm2O3为复合颜料,聚氨酯(PU)为黏合剂,制备了PU/bronze-Sm2O3复合涂层。系统研究了涂层的红外发射率、近红外吸收性能及力学性能。结果表明:Sm2O3的存在可有效降低涂层对1.06μm与1.54μm近红外光的反射率,青铜粉的存在可有效降低涂层在8-14μm波段的红外发射率;通过调节青铜粉与Sm2O3质量比,涂层在8-14μm波段的红外发射率可在0.422-0.782范围内调节,涂层对1.06μm与1.54μm近红外光的反射率可分别在46.8%-65.0%和49.3%-70.7%范围内调节;所制备PU/bronze-Sm2O3复合涂层具备优良的力学性能,在不同青铜粉与Sm2O3质量比下,其附着力与耐冲击强度分别可达到1级和50kg·cm。 相似文献