修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

15 条数据
?? 中文（中国） ▾

  • Spectroscopic and theoretical studies of potassium sodium l-(+)-tartrate tetrahydrate and l-tartaric acid used as precursors for in situ laser-induced deposition of the catalytically active copper microstructures

    摘要： In this work we study the influence of l-(+)-КNaC4H4O6 × 4H2O (KNaT) and l-H2C4H4O6 (H2T) on the complexation processes occurring during in situ laser-induced catalytic destruction of the organic components of the aqueous solutions with formation of the unsaturated hydrocarbons. For that purpose, ATR-FTIR, Raman, IR, and NIR spectroscopy as well as quantum chemical calculations were implemented. It was observed that hydration of T2? anion via carboxylate groups is stronger than that via hydroxyl groups. We also established the changes in the spectral characteristics of the absorption bands corresponding to vibrations of T2?, HT?, and H2T, at solid state-liquid and acid-salt transitions, depending on concentration of the solution components and the [OH?]/[H2T] ratio. Finally, it was shown that ethylene is a main product of the catalytic destruction of the copper tartrate complexes.

    关键词： IR,Laser-induced copper deposition,DFT calculations,Tartaric acid,ATR-FTIR,Catalysis,NIR,Raman spectroscopy,Sodium potassium tartrate tetrahydrate

    更新于2025-10-22 19:40:53

  • Straw Degradation Behaviors under Different Conditions of Relative Air Humidity and Ultraviolet-A Irradiation

    摘要： In this study, straw was degraded continuously for 150 days under one of three levels of relative air humidity (RH) (90%, 60%, or 30%) to estimate the effect of humidity on straw biodegradation. Moreover, straw was treated with ultraviolet (UV)-A irradiation + 90% RH for 180 days to evaluate the interaction between photodegradation and biodegradation. The effects of 30% and 60% RH on straw degradation was inconspicuous. Straw mass losses at 90% RH and UV-A + 90% RH were 18.5% and 39.1%, respectively. BIOLOG analysis showed that filamentous fungi played a major role in straw biodegradation. Thermogravimetric analysis showed that treatment with UV-A + 90% RH tended to increase the maximum pyrolysis rate and decreased the initial pyrolysis temperature. Compared with 90% RH, infrared spectra analysis showed that functional groups of UV-A + 90% RH treatment, e.g., –CH, –C=O, and the benzene ring structure, clearly decreased. Straw-degrading bacteria were observed by scanning electron microscopy at the beginning and end of UV-A + 90% RH treatment. Results highlight the role of humidity in the degree of straw biodegradation by filamentous fungi. Straw degradation is accelerated by the combined action of photodegradation and biodegradation under high UV-A irradiation and high humidity.

    关键词： Relative air humidity,Biodegradation,TGA,Photodegradation,Ultraviolet-A irradiation,BIOLOG,SEM,ATR-FTIR

    更新于2025-09-23 15:23:52

  • Determination of liquid egg composition using ATR-FTIR spectroscopy and chemometrics

    摘要： BACKGROUND: The use of liquid whole egg (LWE) in food industry as a substitute for shell eggs has been on the increase lately. Since the composition of LWE can easily be changed, determination of protein, lipid, moisture, and total soluble solid (TSS) contents of LWE has also gained importance. Traditional methods usually require more time and effort, and the use of toxic chemicals for sample preparation, where more efficient techniques (faster, cheaper, and more reliable) are needed. In this concern, a novel technique that determines LWE components using ATR-FTIR spectroscopy with partial least square regression (PLS) is presented in this study. RESULTS: The actual values of LWE components were detected by applying reference methods. The accuracy of PLS model was demonstrated by comparing the obtained predictions with the actual values of the component. High coefficients of determination values, which are 0.950, 0.992, 0.994, and 0.972, were achieved for protein, lipid, moisture, and TSS validation data sets, respectively. The error values, namely RMSEC, RMSECV, and RMSEP, were obtained in the range of 0.404-0.978, 0.57-1.82, and 0.83-1.84, respectively. CONCLUSION: ATR-FTIR spectroscopy coupled with chemometrics can provide a rapid and sensitive method for quality control of liquid egg composition.

    关键词： chemometrics,composition,Liquid whole egg,ATR-FTIR spectroscopy,reference method

    更新于2025-09-23 15:23:52

  • Rapid quantification of clove (Syzygium aromaticum) and spearmint (Mentha spicata) essential oils encapsulated in a complex organic matrix using an ATR-FTIR spectroscopic method

    摘要： Essential oils (EOs) are often encapsulated in various and complex matrices to protect them against potential degradation or to control their release. To achieve an optimum use in food products, their rapid and precise quantification after encapsulation and storage is required. Hence, a rapid ATR-FTIR method was developed and tested with two encapsulated essential oils (EOs): clove (Syzygium aromaticum) and spearmint (Mentha spicata);. Despite, the complexity of the matrix, this method coupled with univariate or multivariate regression models exhibited high potential for global quantification of the two encapsulated EOs. For clove EO, in relation to the major presence of eugenol and eugenol acetate, an analysis based on a unique band (1514 cm-1) was sufficient to obtain a good prediction with RMSEP value of 0.0173 g of EO per g of matrix. For spearmint oil which is characterized by numerous terpenoid compound, three bands (799, 885, and 1680–1676 cm-1) were suitable for a good prediction with RMSEP value of 0.0133. ATR-FTIR method was compared with a reference gas chromatography FID quantitative method in an EO release experiment and its efficiency was evaluated through modeling by the Avrami equation. Beside time saving, the ATR-FTIR method was also capable of monitoring the EO profile. This method could be easily adapted as a routine analysis in the EOs industry as quality control.

    关键词： Encapsulation,ATR-FTIR,Spearmint,Essential oils,Quantification,Clove

    更新于2025-09-23 15:21:21

  • Attenuated total reflectance spectroscopy to diagnose skin cancer and to distinguish different metastatic potential of melanoma cell

    摘要： Early diagnosing of skin cancer and investigation of metastatic potential of cancer cells are very important to treat it appropriately. Infrared spectroscopy of biological tissues is an emerging technique which gives the spectral differences between healthy and diseased cells. In this work, we have demonstrated that attenuated total re?ectance Fourier transform (ATR-FTIR) spectroscopy can be used in diagnostic of skin cancer and in differentiating metastatic potential of cancer cells. Using IR spectroscopy, we can identify various types of cancer such as basal cell carcinoma, malignant melanoma, nevus and metastatic potential by alternations in hydration level and molecular changes. We examined biopsy of different types of cancer cells to diagnose skin cancer at early stages by using FTIR spectroscopy. To differentiate metastases we examined two human melanoma cells of same patient but at different metastatic potential and two murine melanoma cells with common genetic background but different metastatic potential. Our ?ndings revealed that melanoma changes the permeability of cell membrane and higher metastatic potential is related to the hydration level of cell membrane. Thus, ATR-FTIR spectroscopy is a potential technique to help in early diagnosing of skin cancer and to differentiate different metastatic potentials.

    关键词： ATR-FTIR,Metastatic,spectroscopy,melanoma

    更新于2025-09-23 15:21:01

  • Dynamic Diffusion of Disperse Dye in a Polyethylene Terephthalate Film from an Infrared Spectroscopic Perspective

    摘要： The di?usion behavior of a typical disperse dye, disperse red 9 (DR 9), in the polyethylene terephthalate (PET) ?lm at di?erent temperatures was investigated by attenuated total re?ection?Fourier transform infrared spectroscopy and 2D correlation spectroscopy (2Dcos) analyses. According to the Fickian di?usion model, the calculated di?usion coe?cients of DR 9 in the PET ?lm at di?erent temperatures were observed to increase with temperature, which might be attributed to the increased free volume and thermal motion in the PET matrix and the rapid movement of DR 9 molecules at higher temperatures. In-detail analysis of the di?usion spectra discerned various kinds of molecular interactions, including intramolecular hydrogen bonding interactions of DR 9 and dipole?dipole and π?π interactions between DR 9 and PET. Among these, the dipole?dipole interactions between CO groups of DR 9 and PET occurred ?rst and played a vital role during the di?usion process of DR 9, as deduced from the sequence order of group motions in 2Dcos analysis.

    关键词： ATR-FTIR spectroscopy,2D correlation spectroscopy,polyethylene terephthalate,diffusion,disperse dye

    更新于2025-09-23 15:19:57

  • On the spectroscopic cum chemometric approach for differentiation and classification of inkjet, laser and photocopier printed documents

    摘要： The potential of ATR-FTIR spectroscopy combined with chemometric methods is explored for the rapid and no-destructive forensic investigation of inkjet, laser and photocopier printed documents. The aim of the present study is to ascertain the source of origin of unknown printed documents, i.e., whether it belongs to the laser or inkjet or photocopier devices as well asand also to visualize the intra-variations present in the same types of printed documents. It is observed that these printing inks contain polystyrene, bisphenol A, methyl acrylate and aromatic ethers as the main chemical constituents. The standard normal variate normalization is performed in order to eliminate the differences caused by the amount of toner powder/inks. The discrimination among printed documents is achieved by using chemometric methods including hierarchal cluster analysis and principal component analysis. Further, linear discriminant analysis is used to classify the unknown printed documents into its respective class of printing devices. The present methodology provides robust, non-destructive, reproducible, and simultaneous identification methods for printed documents.

    关键词： Principal Component Analysis,Photocopier,ATR-FTIR,Linear Discriminant Analysis,Laser printed,Inkjet

    更新于2025-09-19 17:13:59

  • Ligand Binding-Induced Structural Changes in the M <sub/>2</sub> Muscarinic Acetylcholine Receptor Revealed by Vibrational Spectroscopy

    摘要： M2 muscarinic acetylcholine receptor (M2R) is a prototypical G protein-coupled receptor (GPCR) that responds to acetylcholine and mediates various cellular responses in the nervous system. Here, we used Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy analyses on M2R reconstituted in lipid membrane to understand the molecular mechanism behind the ligand binding-induced conformational changes. Upon agonist binding, M2R shows large spectral change of amide-I band corresponding to backbone C=O stretch, which likely connects with the receptor activation in lipid environment. These results pave the way to probe effects of different ligand binding on GPCRs using vibrational spectroscopy.

    关键词： ATR-FTIR spectroscopy,GPCR,M2R,Ligand,acetylcholine

    更新于2025-09-12 10:27:22

  • Structural characterization of Argania spinosa Moroccan wooden artifacts during natural degradation progress using infrared spectroscopy (ATR-FTIR) and X-Ray diffraction (XRD)

    摘要： The present work is focused on spectroscopic study of four samples of Argan wooden artifact pertaining to the 17th, 18th, 20th and 21st centuries. The objective is to characterize their unknown structures by the study of their non degraded parts and to investigate changes occurred in their degraded parts due to the natural degradation process. Attenuated total re?ectance Fourier transform infrared spectroscopy gauges the presence of many functional groups related to cellulose I and/or II (OH, C–O–C and –CH2), hemicelluloses (particularly C?O (cid:2)1), and lignin (OH phenolic, Car-O and C?Car) and provides qualitative information on the state of wood alteration by informing on the evolution of new former C?O bands. The degree of conversion to carbonyl group, especially quinone or p-quinone at 1650 cm (cid:2)1, is correlated to lignin degradation, while the absence of the C?O acetoxy absorption is ascribable to occurred deterioration in hemicelluloses, and (cid:2)1. X-ray diffraction determines the presence of two forms of cellulose; amorphous cellulose at 18.5(cid:3) 2θ and predominant crystalline cellulose Iβ at 2θ ? 22.6(cid:3) which characterized by an intense peak. The decrease of crystallinity index values con?rms the deterioration level and obvious changes in crystallinity level. However, the microcrystalline structure appears unaltered because no signi?cant changes were observed for calculated cristallite seize. The obtained results depend on the prolonged time of ageing, natural deterioration phenomena, and wood part (internal or external) that is exposed to degradation. The combination of these two methods is useful for an accurate estimation of the degradation level of argan wood.

    关键词： Chemistry,Argan wood artifact,XRD,Analytical chemistry,Natural product chemistry,Materials Chemistry,Natural degradation,Archaeology,ATR-FTIR spectroscopy,Crystallinity,Lignocelluloses,Structural characterization,Materials Science,Organic chemistry

    更新于2025-09-12 10:27:22

  • Infrared attenuated total reflection spectroscopic analysis and quantitative detection of forage spectral features in ruminant systems

    摘要： This study aimed to (1) access protein molecular structure profile and metabolic characteristics of model forages [Foreign sourced-origin (coded as: “FSO”, n = 7 vs. Chinese sourced-origin alfalfa hay “CSO”, n = 5] in ruminant systems; (2) Quantify the relationship between forage protein molecular structures and protein utilization and availability. Advanced non-invasive vibrational molecular spectroscopic technique (ATR-FTIR: Attenuated Total Reflection Fourier Transform Infrared spectroscopy) with chemometrics was applied to reveal forage protein molecular structure. Both univariate and multivariate molecular spectral analyses were applied to study molecular structure features in model forages. The molecular structure study provided the detailed protein structure profiles of Amide I and Amide II areas and height, total Amide I and II area ratios, Amide I to II height ratio as well as Amide I to II area ratio using ATR-FTIR spectroscopy. The results showed FSO and CSO had similar (P > 0.05) protein rumen degradation kinetics. However, FSO had superior quality than CSO in intestinal (IDP) and total digestible protein (TDP) and truly absorbed nutrient supply (P < 0.05). As intestinal digestion of protein, FSO was higher (P < 0.05) in protein digestion in terms of: intestinal digestibility of rumen undegraded protein (dIDP: 47.5 vs. 38.3 %RUP); Intestinal digestible protein (IDP: 17.6 vs. 13.7 %CP). As truly absorbed nutrient supply, FSO contained higher (P < 0.05) truly absorbed rumen synthesized microbial protein, absorbable rumen undegradable feed protein in the small intestine, total truly digested protein in the small intestine, metabolizable protein and Feed Milk Value (FMVDVE: 1.2 vs. 1.1 g/kg DM). The molecular structure-nutrition interactive relationship study showed that protein molecular structure profiles were highly associated to protein rumen degradation kinetics, significantly correlated to protein subfractions, protein intestinal digestion, and truly absorbed nutrient supply in ruminant systems.

    关键词： Vibrational molecular spectroscopy-ATR-FTIR,Intestine digestion,Model forages,Truly absorbed protein supply,Rumen degradation,Protein molecular structure and conformation,Univariate and multivariate molecular spectral analyses

    更新于2025-09-12 10:27:22