JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2017
·
IF 3.154
Zong Tan,Ting-ting Lou,Zhi-xuan Huang,Jing Zong,Ke-xin Xu,Qi-feng Li,Da Chen
Better milk safety control can offer important means to promote public health. However, few technologies can detect different types of contaminants in milk simultaneously. In this regard, the present work proposes a single-drop Raman imaging (SDRI) strategy for semiquantitation of multiple hazardous factors in milk solutions. By developing SDRI strategy that incorporates the coffee-ring effect (a natural phenomenon often presents in a condensed circle pattern after a drop evaporated) for sample pretreatment and discrete wavelet transform for spectra processing, the method serves well to expose typical hazardous molecular species in milk products, such as melamine, sodium thiocyanate and lincomycin hydrochloride, with little sample preparation. The detection sensitivity for melamine, sodium thiocyanate, and lincomycin hydrochloride are 0.1 mg kg–1, 1 mg kg–1, and 0.1 mg kg–1, respectively. Theoretically, we establish that the SDRI represents a novel and environment-friendly method that screens the milk safety efficiently, which could be well extended to inspection of other food safety.
研究领域:
食品安全
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分析化学
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光谱学
✓ 已验证
DOI
PubMed
高影响因子
International Journal of Environmental Research and Public Health
·
2017
·Vol. 14
·期 10
·1163
·
IF 2.101
Fang Li,Anxiang Lu,Jihua Wang
A modeling method based on discrete wavelet transform (DWT) was introduced to analyze the concentration of chromium, copper, zinc, arsenic and lead in soil with a portable X-ray fluorescence (XRF) spectrometer. A total of 111 soil samples were collected and observed. Denoising and baseline correction were performed on each spectrum before modeling. The optimum conditions for pre-processing were denoising with Coiflet 3 on the 3rd level and baseline correction with Coiflet 3 on the 9th level. Calibration curves were established for the five heavy metals (HMs). The detection limits were compared before and after the application of DWT, the qualitative detection limits and the quantitative detection limits were calculated to be three and ten times as high as the standard deviation with silicon dioxide (blank), respectively. The results showed that the detection limits of the instrument using DWT were lower, and that they were below national soil standards; the determination coefficients (R2) based on DWT-processed spectra were higher, and ranged from 0.990 to 0.996, indicating a high degree of linearity between the contents of the HMs in soil and the XRF spectral characteristic peak intensity with the instrument measurement.Keywords:X-ray fluorescence;heavy metal;soil;wavelet transform
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Agronomy-Basel
·
2025
·Vol. 15
·期 8
·1779
·
IF 3.4
Meichen Liu,Shengwei Zhang,Jing Gao,Bo Wang,Kedi Fang,Lu Liu,Shengwei Lv,Qian Zhang
The salinization of agricultural soils is a serious threat to farming and ecological balance in arid and semi-arid regions. Accurate estimation of soil water-soluble ions (calcium, carbonate, magnesium, and sulfate) is necessary for correct monitoring of soil salinization and sustainable land management. Hyperspectral ground-based data are valuable in soil salinization monitoring, but the acquisition cost is high, and the coverage is small. Therefore, this study proposes a two-stage deep learning framework with multispectral remote-sensing images. First, the wavelet transform is used to enhance the Transformer and extract fine-grained spectral features to reconstruct the ground-based hyperspectral data. A comparison of ground-based hyperspectral data shows that the reconstructed spectra match the measured data in the 450–998 nm range, with R2up to 0.98 and MSE = 0.31. This high similarity compensates for the low spectral resolution and weak feature expression of multispectral remote-sensing data. Subsequently, this enhanced spectral information was integrated and fed into a novel multiscale self-attentive Transformer model (MSATransformer) to invert four water-soluble ions. Compared with BPANN, MLP, and the standard Transformer model, our model remains robust across different spectra, achieving an R2of up to 0.95 and reducing the average relative error by more than 30%. Among them, for the strongly responsive ions magnesium and sulfate, R2reaches 0.92 and 0.95 (with RMSE of 0.13 and 0.29 g/kg, respectively). For the weakly responsive ions calcium and carbonate, R2stays above 0.80 (RMSE is below 0.40 g/kg). The MSATransformer framework provides a low-cost and high-accuracy solution to monitor soil salinization at large scales and supports precision farmland management.
研究领域:
遥感
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土壤科学
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农业监测
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深度学习
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环境监测
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SPECTROSCOPY
·
2022
·
IF 3.588
Biao Ma,Wensheng Cai,Xueguang Shao
Analysis of the confined water in hydrogels is essential for understanding the chemical and physical properties. Methods to quantify the content and study the structure of water in hydrogel using near-infrared (NIR) spectroscopy were proposed. The NIR spectra of poly-N,N-dimethylacrylamide (PDMAA) hydrogel with different water contents were measured at different temperatures. A partial least squares (PLS) model was established using the spectra of the samples with water content (wh) from 0.9 to 387.6%. Continuous wavelet transform (CWT) was adopted to calculate the resolution enhanced spectra from which the spectral features of water species with free OH (S0) and with one or two hydrogen bonds (S1 and S2) was obtained. The variation of these water species with water content suggests the existence of the water molecules bonding to NH groups by one hydrogen bond (S1NH) and hydrating the CH groups of the polymer network and bulk-like water. Moreover, the variation of water structures with temperature shows that the release of bulk-like water occurs in the phase transition of the hydrogel, but the S1NH and the hydration water stay unchanged. The former explains the sudden volume shrinkage for the phase transition and the latter may be the reason for the shape memory effect in the repeated swelling and deswelling of hydrogels.
研究领域:
分析化学
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高分子科学
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光谱学
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材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
Journal of Food Measurement and Characterization
·
2022
·Vol. 16
·期 5
·3438-3450
·
IF 3.006
Liu Yan,Wang Chao,Xia Zhenzhen,Wang Qiao,Duan Shuo
A method for monitoring the freshness of crayfish by near-infrared spectroscopy combined with chemometrics was proposed in this study. The total volatile basic nitrogen (TVBN), K value and biogenic amine were adopted as the indexes of freshness. The 120 peeled and the 120 whole tail samples were utilized to build the quantitative models by partial least squares (PLS) regression, respectively. The spectral pretreatment and the variable selection methods were adopted to further improve the models. For the models of TVBN and K value, the combination of continuous wavelet transform (CWT) and randomization test (RT) method could improve the predictability effectively. The combination of 1st derivative and RT method could get better results for the optimization of the biogenic amine models. The optimized models were evaluated by 40 peeled and the 40 whole tail samples, and then utilized to predict the three indexes in another 32 peeled tails and 40 whole tail samples for practical application. Reasonable results were obtained for the samples with TVBN levels ranging from 28.01 mg/kg to 284.89 mg/kg, K value levels ranging from 13.04 to 87.36% and biogenic amines ranging from 148.57 mg/kg to 663.71 mg/kg. For the TVBN, K value and biogenic amine in the 32 peeled tail samples, the correlation coefficients between the results calculated by the optimized models and those measured by the standard methods were 0.95, 0.94 and 0.96 respectively. As to the three freshness indexes in 40 whole tail samples, the correlation coefficients were 0.95, 0.93 and 0.94, respectively.
研究领域:
食品科学
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光谱学
·
化学计量学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-12
·
IF 11.878
Wang Dewen,Li Qun,Han Ce,Lu Qingqing,Xing Zhicai,Yang Xiurong
Herein, ruthenium (Ru) and iridium (Ir) are introduced to tailor the atomic and electronic structure of self-supported nickel-vanadium (NiV) layered double hydroxide to accelerate water splitting kinetics, and the origin of high hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities are analyzed at atomic level. X-ray photoelectron spectroscopy and X-ray absorption near-edge structure spectroscopy studies reveal synergistic electronic interactions among Ni, V, and Ru (Ir) cations. Raman spectra and Fourier and wavelet transform analyses of the extended X-ray absorption fine structure indicate modulated local coordination environments around the Ni and V cations, and the existence of V vacancies. The Debye–Waller factor suggests a severely distorted octahedral V environment caused by the incorporation of Ru and Ir. Theoretical calculations further confirm that Ru or Ir doping could optimize the adsorption energy of intermediates in the Volmer and Heyrovsky steps for HER and accelerate the whole kinetic process for OER.
研究领域:
材料科学
·
电化学
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催化
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光谱学
·
理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）