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土壤全氮田间Vis/NIR光谱测定方法研究 被引量:2
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作者 汪善勤 舒宁 张海涛 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2008年第4期808-812,共5页
应用Vis/NIR光谱直接测定原始土壤属性具有重要的研究和应用价值。选取我国中部水稻土和潮土共103个土样,对比分析了两种土壤在田间环境下的湿态(Rw)和干态(Rd)光谱特征。采用相对变换光谱方法对湿态光谱进行了处理,结果表明该方法能够... 应用Vis/NIR光谱直接测定原始土壤属性具有重要的研究和应用价值。选取我国中部水稻土和潮土共103个土样,对比分析了两种土壤在田间环境下的湿态(Rw)和干态(Rd)光谱特征。采用相对变换光谱方法对湿态光谱进行了处理,结果表明该方法能够有效降低土壤水分的干扰和消除部分噪声,得到的变换光谱(Rn)与干态光谱在信息量和特征方面具有很高的相似度。以此建立了土壤TN的PLS回归估计模型,检验结果表明,Rn对水稻土和潮土TN的估计模型精度均高于Rw,修正判定系数分别从0.26和0.46提高到0.53和0.62。因此,相对光谱变换方法能够有效提高应用田间土壤光谱估计土壤参数的能力,建立的PLS模型可以用于测定TN含量,研究结果可作为实现田间实时分析土壤属性的工作基础。 展开更多
关键词 全氮 vis/nir光谱 相对变换方法
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MIV波长优选改善VIS/NIR光谱TVB-N模型性能研究 被引量:3
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作者 陈亦凡 李芸婧 +3 位作者 彭苗苗 杨春勇 侯金 陈少平 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2020年第5期1413-1419,共7页
挥发性盐基氮(TVB-N)是衡量肉品新鲜的重要理化指标,利用可见/近红外(VIS/NIR)光谱对TVB-N含量进行定量检测具有重要意义。预测模型是VIS/NIR光谱检测TVB-N含量性能的关键要素,使其兼顾准确性与稳健性可有效改善TVB-N的定量分析结果。... 挥发性盐基氮(TVB-N)是衡量肉品新鲜的重要理化指标,利用可见/近红外(VIS/NIR)光谱对TVB-N含量进行定量检测具有重要意义。预测模型是VIS/NIR光谱检测TVB-N含量性能的关键要素,使其兼顾准确性与稳健性可有效改善TVB-N的定量分析结果。以猪肉为例,采集51组不同新鲜度样本的VIS/NIR光谱数据,去除低信噪比区间200~450和900~1000 nm,选取有效波段450~900 nm的光谱数据用于建模。随后利用主成分分析(PCA)对光谱信息降维,构建一个反向传播神经网络(BPNN)模型。在此基础上,提出用平均影响值(MIV)方法从有效波段中优选与肉质TVB-N含量强相关的特征波长,最终基于221个优选波长,构建一个MIV-PCA-BPNN预测模型。实验表明,初步构建的PCA-BPNN非线性预测模型,校正相关系数(R_C)和校正均方根误差(RMSEC)分别为0.96和1.47 mg/100 g,预测相关系数(R_P)和预测均方根误差(RMSEP)分别为0.93和1.74 mg/100 g,模型稳健性指标为1.18,优于经典的线性预测模型主成分分析回归和偏最小二乘回归,证明TVB-N具有较强的非线性效应。最终构建的MIV-PCA-BPNN预测模型的R_C和RMSEC分别为0.98和1.21 mg/100 g,R_P和RMSEP分别为0.96和1.12 mg/100 g,模型稳健性指标为1.08,在所构建的预测模型中,RMSEC和RMSEP最小,RC和RP最大,模型的准确性和稳健性最佳。另外,MIV方法筛选出的特征波长集中在7个波峰附近,皆分布于肉品中化学成分的吸收区内,且与TVB-N中的含氢基团的特征吸收峰表现出高度一致性,为利用MIV方法筛选波长变量提供了理论依据。研究结果显示,MIV波长优选可有效改善预测模型的性能,为利用神经网络剔除无关波长变量提供了新思路,所构建的MIV-PCA-BPNN预测模型满足了肉质中TVB-N定量分析的需求。 展开更多
关键词 vis/nir光谱检测 反向传播神经网络 波长优选 挥发性盐基氮
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利用VIS/NIR反射光谱快速检测柿饼加工中水分含量 被引量:1
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作者 赵鹏瑶 彭月梅 吴建虎 《农产品加工》 2021年第17期49-52,56,共5页
水分是柿饼的重要组成成分,也是影响柿饼制作过程的重要因素。利用可见/近红外反射光谱对柿饼制作过程中的水分含量进行检测。首先,获取柿饼在不同加工阶段的可见/近红外反射光谱(400~1000 nm),采用烘干法测定柿饼水分含量。然后,对光... 水分是柿饼的重要组成成分,也是影响柿饼制作过程的重要因素。利用可见/近红外反射光谱对柿饼制作过程中的水分含量进行检测。首先,获取柿饼在不同加工阶段的可见/近红外反射光谱(400~1000 nm),采用烘干法测定柿饼水分含量。然后,对光谱进行Mean smoothing(MS)平滑、多元散射校正(MSC)和一阶导数(1-D)预处理。最后,对不同预处理光谱,结合样本水分含量,使用Samples set partitioning based on joint x-y distance(SPXY)方法划分校正集和验证集,基于SPA方法选择特征波长,建立多元线性回归(MLR)预测模型。结果表明,反射光谱经过MS处理后,确定的9个最优波长组合建立水分检测模型的预测结果最好:预测相关系数(Rp)为0.9690,预测标准残差(SEP)为3.4729%,可见/近红外反射光谱技术可以较好地预测柿饼制作过程中的的水分含量。研究可为柿饼加工过程中的品质快速检测提供一定的技术支撑。 展开更多
关键词 柿饼 水分含量 vis/nir光谱反射 SPXY算法 SPA算法
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Flexible Vis/NIR wireless sensing system for banana monitoring
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作者 Meng Wang Bingbing Wang +2 位作者 Ruihua Zhang Zihao Wu Xinqing Xiao 《Food Quality and Safety》 SCIE CAS CSCD 2023年第3期492-502,共11页
Objectives:The quality of the fruit seriously affects the economic value of the fruit.Fruit quality is related to many ripening parameters,such as soluble solid content(SSC),pH,and firmness(FM),and is a complex proces... Objectives:The quality of the fruit seriously affects the economic value of the fruit.Fruit quality is related to many ripening parameters,such as soluble solid content(SSC),pH,and firmness(FM),and is a complex process.Traditional methods are inefficient,do not guarantee quality,and do not adapt to the current rhythm of the fruit market.In this paper,a was designed and implemented for quality prediction and maturity level classification of Philippine Cavendish bananas.Materials and Methods:The quality changes of bananas in different stages were analyzed.Twelve light intensity reflectance values for each maturity stage were compared to conventionally measured SSC,FM,PH,and color space.Results:Our device can be compared with traditional forms of quality measurement.The experimental results show that the established predictive model with specific preprocessing and modeling algorithms can effectively determine various banana quality parameters(SSC,pH,FM,L^(*),a^(*),and b^(*)).The RPD values of SSC and a^(*)were greater than 3.0,the RPD values of L^(*)and b^(*)were between 2.5 and 3.0,and the pH and FM were between 2.0 and 2.5.In addition,a new banana maturity level classification method(FSC)was proposed,and the results showed that the method could effectively classify the maturity level classes(i.e.four maturity levels)with an accuracy rate of up to 97.5%.Finally,the MLR and FSC models are imported into the MCU to realize the near-range and long-range real-time display of data.Conclusions:These methods can also be applied more broadly to fruit quality detection,providing a basic framework for future research. 展开更多
关键词 BANANA vis/nir FLEXIBILITY ripening classification CHEMOMETRICS
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Development and Applications of Ruggedized VIS/NIR Spectrometer System for Oilfield Wellbores 被引量:1
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作者 Go FUJISAWA Tsutomu YAMATE 《Photonic Sensors》 SCIE EI CAS 2013年第4期289-294,共6页
The development and applications of a ruggedized visible to near-infrared (VIS/NIR) spectrometer system capable of measuring fluid spectra in oilfield wellbores are presented. Real-time assessment of formation fluid... The development and applications of a ruggedized visible to near-infrared (VIS/NIR) spectrometer system capable of measuring fluid spectra in oilfield wellbores are presented. Real-time assessment of formation fluid properties penetrated by an oilfield wellbore is critically important for oilfield operating companies to make informed decisions to optimize the development plan of the well and hydrocarbon reservoir. A ruggedized VIS/NIR spectrometer was designed and built to measure and analyze hydrocarbon spectra reliably under the harsh conditions of the oilfield wellbore environment, including temperature up to 175 ~C, pressure up to 170MPa, and severe mechanical shocks and vibrations. The accuracy of hydrocarbon group composition analysis was compared well with gas chromatography results in the laboratory. 展开更多
关键词 vis/nir spectroscopy hydrocarbon compositions oilfield wellbore in situ measurement real time
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土壤定量遥感技术研究进展 被引量:9
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作者 汪善勤 舒宁 《遥感信息》 CSCD 2007年第6期89-93,共5页
分述了目前VIS/NIR地面光谱、多光谱和高光谱数据及分析技术在土壤定量遥感研究中的应用情况和进展,指出多源遥感数据的应用是该领域的主要趋势,并简要分析了目前研究中存在的问题。
关键词 定量遥感 vis/nir地面光谱 多光谱和高光谱数据 多源遥感数据
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基于可见光/近红外高光谱技术的窖泥总酸的分布 被引量:5
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作者 朱敏 孙婷 +3 位作者 白直真 罗惠波 田建平 黄丹 《食品与发酵工业》 CAS CSCD 北大核心 2020年第8期111-117,共7页
基于近红外(near-infrared,NIR)以及可见光(visible,VIS)高光谱技术快速评估窖泥总酸的分布。化学计量法结合计算机技术分析窖泥在近红外以及可见光波段下的高光谱数据,结合总酸实测值建立偏最小二乘回归、最小二乘支持向量机2种预测模... 基于近红外(near-infrared,NIR)以及可见光(visible,VIS)高光谱技术快速评估窖泥总酸的分布。化学计量法结合计算机技术分析窖泥在近红外以及可见光波段下的高光谱数据,结合总酸实测值建立偏最小二乘回归、最小二乘支持向量机2种预测模型。根据模型的表现性能,最优模型为可见光区域下的SNV-SPA-SVM模型,训练集的决定系数Rcal2为0.9985,均方根误差为0.0049 g/kg,测试集的决定系数Rpre2为0.9991,均方根误差为0.0038 g/kg,并计算得到不同窖龄、不同层次窖泥总酸度的可视化分布图。结果表明,将高光谱技术应用于窖泥总酸的快速无损检测是可行的,此技术帮助白酒企业快速发现问题,及时调整工艺,防止窖泥酸化和老化现象的发生,同时为中国白酒行业传统技术的转型升级以及智能化在线实时监控窖泥质量提供了有力的技术支持。 展开更多
关键词 vis/nir高光谱技术 窖泥 总酸 快速无损检测 可视化
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Structural and Optical Characteristics of Silica Nanotubes Using CNTs as Template 被引量:1
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作者 Rasoul Malekfar M.Hassan Rajabi M.Hossein Majless Ara 《Nano-Micro Letters》 SCIE EI CAS 2010年第4期268-271,共4页
Silica coated multi-wall carbon nanotubes(MWCNTs),silica@MWCNTs and nanocomposites were synthesized by a sol-gel method.By using the synthesized nanocomposites and also CNTs as templates,silica nanotubes(silica-NTs) w... Silica coated multi-wall carbon nanotubes(MWCNTs),silica@MWCNTs and nanocomposites were synthesized by a sol-gel method.By using the synthesized nanocomposites and also CNTs as templates,silica nanotubes(silica-NTs) were prepared.The optical properties of fabricated nanocomposites and nanotubes were characterized by back-scattering micro Raman,UV/Vis/NIR and FT-IR spectra,which show the presence of CNTs structure in the nanocomposites.UV/Vis/NIR and FT-IR spectra also show the presence of silica compounds.The recorded spectra from UV/Vis/NIR and FT-IR also confirm the presence of silica compounds in the nanotubes.The results of FE-SEM imaging data indicate that the synthesized samples are MWCNTs coated uniformly by silica molecules,which act as the template to synthesize silica-NTs. 展开更多
关键词 Carbon nanotubes(MWCNTs) Silica RAMAN Ultra violet/visible/near infrared(UV/vis/nir)
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Spectral characteristics of banded iron formations in Singhbhum craton,eastern India:Implications for hematite deposits on Mars
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作者 Mahima Singh Jayant Singhal +3 位作者 K.Arun Prasad V.J.Rajesh Dwijesh Ray Priyadarshi Sahoo 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第6期927-936,共10页
Banded iron formations (BIFs) are major rock units having hematite layers intermittent with silica rich layers and formed by sedimentary processes during late Archean to mid Proterozoic time. In terrestrial environm... Banded iron formations (BIFs) are major rock units having hematite layers intermittent with silica rich layers and formed by sedimentary processes during late Archean to mid Proterozoic time. In terrestrial environment, hematite deposits are mainly found associated with banded iron formations. The BIFs in Lake Superior (Canada) and Carajas (Brazil) have been studied by planetary scientists to trace the evolution of hematite deposits on Mars. Hematite deposits are extensively identified in Meridiani region on Mars. Many hypotheses have been proposed to decipher the mechanism for the formation of these deposits. On the basis of geomorphological and mineralogical studies, aqueous environment of deposition is found to be the most supportive mechanism for its secondary iron rich deposits. In the present study, we examined the spectral characteristics of banded iron formations of Joda and Daitari located in Singhbhum craton in eastern India to check its potentiality as an analog to the aqueous/marine environment on Mars. The prominent banding feature of banded iron formations is in the range of few millimeters to few centimeters in thickness. Fe rich bands are darker (gray) in color compared to the light reddish jaspilitic chert bands. Thin quartz veins (〈4 mm) are occasionally observed in the handspecimens of banded iron formations. Spectral investigations have been conducted in VIS/NIR region of electromagnetic spectrum in the laboratory conditions. Optimum absorption bands identified include 0.65, 0.86, 1.4 and 1.9 μm, in which 0.56 and 0.86 μm absorption bands are due to ferric iron and 1.4 and 1,9 μm bands are due to OH/H2O. To validate the mineralogical results obtained from VlS/NIR spectral radiometry, laser Raman and Fourier transform infrared spectroscopic techniques were utilized and the results were found to be similar. Goethite-hematite association in banded iron formation in Singhbhum craton suggests dehydration activity, which has altered the primary iron oxide phases into the secondary iron oxide phases. The optimum bands identified for the minerals using various spectroscopic techniques can be used as reference for similar mineral deposits on any remote area on Earth or on other hydrated planetary surfaces like Mars. 展开更多
关键词 Banded iron formation Singhbhum craton vis/nir spectroscopy Raman spectroscopy Terrestrial analog Mars
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硝酸盐腌肉中硝酸盐添加量的判别分析
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作者 万国玲 《食品安全导刊》 2019年第6期58-59,共2页
本文利用Vis/NIR高光谱对硝酸盐腌肉中亚硝酸钠的添加量进行判别分析,选用4种方法对原始光谱进行预处理,建立全波段和特征波段的PLSDA模型。结果表明:经SNV预处理后PLSDA判别模型校正集准确率为88%,预测集准确率为81%。
关键词 硝酸盐腌肉 vis/nir PLSDA
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Nondestructive perception of potato quality in actual online production based on cross-modal technology
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作者 Qiquan Wei Yurui Zheng +6 位作者 Zhaoqing Chen Yun Huang Changqing Chen Zhenbo Wei Shuiqin Zhou Hongwei Sun Fengnong Chen 《International Journal of Agricultural and Biological Engineering》 SCIE 2023年第6期280-290,共11页
Nowadays,China stands as the global leader in terms of potato planting area and total potato production.The rapid and nondestructive detection of the potato quality before processing is of great significance in promot... Nowadays,China stands as the global leader in terms of potato planting area and total potato production.The rapid and nondestructive detection of the potato quality before processing is of great significance in promoting rural revitalization and augmenting farmers’income.However,existing potato quality sorting methods are primarily confined to theoretical research,and the market lacks an integrated intelligent detection system.Therefore,there is an urgent need for a post-harvest potato detection method adapted to the actual production needs.The study proposes a potato quality sorting method based on cross-modal technology.First,an industrial camera obtains image information for external quality detection.A model using the YOLOv5s algorithm to detect external green-skinned,germinated,rot and mechanical damage defects.VIS/NIR spectroscopy is used to obtain spectral information for internal quality detection.A convolutional neural network(CNN)algorithm is used to detect internal blackheart disease defects.The mean average precision(mAP)of the external detection model is 0.892 when intersection of union(IoU)=0.5.The accuracy of the internal detection model is 98.2%.The real-time dynamic defect detection rate for the final online detection system is 91.3%,and the average detection time is 350 ms per potato.In contrast to samples collected in an ideal laboratory setting for analysis,the dynamic detection results of this study are more applicable based on a real-time online working environment.It also provides a valuable reference for the subsequent online quality testing of similar agricultural products. 展开更多
关键词 cross-modal technology potato quality YOLOv5s vis/nir spectroscopy online nondestructive detection
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Rapid detection of total phenolics,antioxidant activity and ascorbic acid of dried apples by chemometric algorithms 被引量:1
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作者 NecatiÇetin Cevdet Sağlam 《Food Bioscience》 SCIE 2022年第3期662-669,共8页
Multivariate approaches like machine learning are commonly used in estimation of biochemical traits from spectral and color characteristics of foodstuffs and agricultural commodities.In present study,windfall apples o... Multivariate approaches like machine learning are commonly used in estimation of biochemical traits from spectral and color characteristics of foodstuffs and agricultural commodities.In present study,windfall apples of Golden Delicious,Oregon Spur and Granny Smith cultivars were dried in open-sun,controlled greenhouse,microwave oven(200W),hybrid system(100W+60℃),convective dryer(70℃)and freeze-dryer(−55℃).Spectral,chromatic and biochemical characteristics of dried apples were determined and assessed through machine learning algorithms.Total phenolic matter,DPPH(2,2-Diphenyl-1-picrylhydrazyl),FRAP(Ferric Reducing Antioxidant Power)and ascorbic acid content were estimated with the use of five different machine learning algorithms(artificial neural networks,k-nearest neighbor,random forest,gaussian processes and support vector regression).The most successful results were achieved in estimation of total phenolic content(R≥0.85).Additionally,Multilayer Perceptron,Support Vector Regression and Gaussian Processes were identified as the best machine learning algorithms in estimation of biochemical compositions of dried apples. 展开更多
关键词 APPLE DRYING Biochemical composition vis/nir spectra Machine learning
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