共查询到20条相似文献,搜索用时 78 毫秒
1.
为快速、便捷地利用近红外光谱检测苹果糖度,设计了以ARM9处理器为核心、以微型光谱仪和自制果托作为光谱检测装置、以Win CE为操作系统的便携式苹果糖度光谱检测仪。以80个苹果样品作为试验对象,采用平滑、多元散射校正、标准正态变量变换等方法对原始光谱进行预处理,结合无信息变量消除法和连续投影算法进行有效波长的筛选,建立基于所选特征波长和全波段的苹果糖度近红外光谱偏最小二乘模型。结果表明,偏最小二乘结合原始光谱信息建模效果最好,其预测相关系数Rp=0.853,预测均方根误差RMSEP=0.534。该检测仪能较好地满足苹果糖度的快速无损检测。该研究为快速、便携的苹果糖度光谱检测仪设计提供了参考。 相似文献
2.
《信息通信》2019,(7)
近年来阿克苏冰糖心苹果假冒产品越发猖獗,据调查显示市面上假冒产品竟超过一半数量,针对此问题,本文主要研究的是阿克苏库车的红旗坡糖心富士苹果,利用了近红外光谱的漫反射原理,来采集近红外光谱对糖心苹果的反射曲线数据,同时使用糖度仪作为品质数据,然后对光谱数据进行了多元散射校正与S-G平滑法的一系列处理,最后通过PLS方法建立糖心苹果的近红外光谱与糖度的预测模型,结合南疆特色来切实的实现糖心苹果的实时无损检测,建立实时检测系统达到分辨真假糖心苹果的目的。本文主要是针对阿克苏冰糖心苹果的糖度来进行一系列的测试,是基于解决现实生活中不法商贩肆意贩卖假冒的阿克苏冰糖心苹果问题所提出的,通过本文实时无损检测的实施有助于为南疆其它水果的无损检测的判别提供理论依据和实用模型。 相似文献
3.
针对目前的农产品成熟度无损检测方法存在检测精度较差的问题,提出基于近红外光谱的大枣成熟度无损检测方法。利用近红外光谱仪采集大枣样品的近红外光谱,并计算采集到的近红外光谱的马氏距离,将超出阈值的马氏距离样品设置为异常样品,为此删除异常的大枣近红外光谱;利用连续投影算法对异常删除的大枣近红外光谱中的波段选择;将大枣近红外光谱波段选择结果作为卷积神经网络输入,通过卷积层和池化层的运算,输出大枣成熟度无损检测结果。实验结果表明:本方法的大枣成熟度无损检测精度最高可达99.12%,无损检测时间最高为11 s,无损检测误差最高为0.06,说明本方法无损检测精度好,具有较高的技术水平和应用价值。 相似文献
4.
本文基于目前国内外对柑橘内部品质的实时无损检测还处在实验室研究阶段,现有在线无损实时检测技术和方法还不成熟且投入商业化应用较少的现状,设计并开发了一套近红外光谱采集与处理软件。该软件采用面向对象化的visual C++编程技术,可以实现实时光谱的显示、光谱文件的管理、光谱信号的实时处理以及光谱预测模型的选择等,解决了一些在线检测中的关键技术问题,为柑橘内部品质的实时无损检测提供了理论指导和参考依据。 相似文献
5.
6.
为了评估微型近红外光谱仪应用于现场水果糖度检测的可行性, 采用粒子群算法结合反向传播(BP)神经网络建立了苹果糖度的无损高精度快速检测方法, 研究了微型近红外光谱仪NIRscan以单波长和阿达玛变换两种测量模式获得的光谱数据, 应用多种不同的数据预处理方法和多元线性回归、偏最小二乘法、粒子群算法(PSO)、BP神经网络等算法建立分析模型。结果表明, 以阿达玛变换工作模式测得的光谱数据更好, 以1阶导数结合Savizky-Golay平滑算法作数据预处理, 应用PSO结合BP神经网络建立的苹果糖度预测模型具有更高的预测精度, 预测相关系数和均方根误差分别为0.9911和0.1502。该微型近红外光谱仪NIRscan用于苹果糖度的现场快速和高精度无损检测具有可行性。 相似文献
7.
水果内部品质近红外动态在线检测研究进展 总被引:5,自引:0,他引:5
近红外光谱技术具有无损检测、分析效率高、速度快、重现性好,适于现场检测和在线分析等特点,并已渗入到各个领域,在提高生产技术水平和改善产品质量方面发挥着重要作用。本文简述了水果近红外光谱在线检测原理和方式及动态在线检测装置的组成,并介绍了在线检测的控制过程及在线检测分析软件。总结了国内外近红外光谱技术在水果内部品质在线检测与分级方面的应用情况,并分析水果内部品质在线检测与分级中存在的问题,指出了水果内部品质近红外光谱在线检测的进一步研究方向。 相似文献
8.
水果内部品质近红外光谱无损检测研究进展 总被引:17,自引:1,他引:16
近红外(NIR)光谱分级技术正越来越广泛地应用于水果的产后加工和质量评判中.介绍了水果内部品质光学特性检测原理;分析了规则反射、透射和漫反射3种光特性测量方法在水果内部品质不同需求检测中的适用性;化学计量学方法是近红外光谱分析技术的一个重要部分,对一些新的预处理方法和回归算法作了介绍;探讨了水果状态对光谱影响及修正方法,如温度补偿、大小修正等;并阐述了水果的糖度、酸度、硬度等定量检测和褐变、黑心、水心、损伤等定性判别的国内外最新研究进展;分析了近红外技术在水果品质检测和控制方面的应用前景. 相似文献
9.
基于近红外光谱的梨果糖浓度无损检测系统 总被引:1,自引:0,他引:1
应用近红外光谱漫发射技术设计了梨果的糖浓度无损便携式检测系统,建立了近红外光谱和梨的糖浓度值之间的关系。以850nm激光二极管作为背景光源,905nm作为特征光源,设计了用于梨的糖浓度无损检测的便携式仪器。将校正集样本结合偏最小二乘法进行建模,并对预测集进行预测。同时使用标准仪器测得梨果糖度标准值,得到了标准糖度值和预测值之间的相关图。其中校正集相关系数为0.99186,RMSEC为0.00175,由此模型进行预测时所得到的预测集相关系数为0.8262,RMSEP=0.00808。实验初步证明,文中所设计仪器可对同一种类的梨的糖浓度进行无损测量。 相似文献
10.
基于可见/近红外漫透射光谱技术,探讨了对不同产地石榴的品质进行快速无损检测的可行性。首先,利用能够有效抑制杂散光影响的动态在线检测装置采集石榴的近红外光谱,测试石榴糖度的真值;然后结合主成分分析法对不同产地的石榴进行聚类分析,大致将样品分为两类;最后建立不同产地石榴的偏最小二乘判别分析模型,模型的判别准确率为97%以上。采用多种预处理方法(S-G平滑、归一化、基线校正、MSC等)建立了两类石榴的单一模型,结果表明:基线校正的效果明显优于其他方法,所建立的四川石榴模型的预测集相关系数R_p为0.82,预测集均方根误差(RMSEP)为0.37,建模集相关系数R_c为0.90,建模集均方根误差(RMSEC)为0.31;云南石榴模型的R_p为0.81,RMSEP为0.33,R_c为0.87,RMSEC为0.27。在后期采用未参与建模的样品的分选验证实验中,两个产地石榴的判别率为95%,糖度的分选准确率可达92.5%。结果表明,近红外光谱在石榴产地的判别和糖度的分选上具有重要意义,可为以后的石榴在线分选研究提供依据。 相似文献
11.
Michael Reilly 《半导体技术》2004,29(12)
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.
Thomas M.Trexler 《半导体技术》2004,29(5)
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
13.
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
14.
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
15.
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
16.
GU Min-fen LIANG Zhong-cheng WANG Ren-zhou DONG Xiang-mei ZHANG Pei-ming CHEN Jia-bi 《光电子快报》2008,4(2):150-152
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor. 相似文献
17.
Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
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
18.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well. 相似文献
19.
Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems. 相似文献
20.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect. 相似文献