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基于多光谱技术分析绿原酸与肌原纤维蛋白相互作用的初步研究 被引量:1
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作者 李杰 郭欣 +3 位作者 袁天帅 屈启超 朱新荣 张建 《食品工业科技》 CAS 北大核心 2024年第5期44-52,共9页
本研究以高白鲑肌原纤维蛋白(Myofibrillar Protein,MP)为研究对象,探究不同浓度(6、30、150、300μmol/g)绿原酸(Chlorogenic Acid,CA)与MP相互作用的结构变化及结合性质。在25℃下孵育形成不同CA-MP复合物,通过测定复合物的理化性质(... 本研究以高白鲑肌原纤维蛋白(Myofibrillar Protein,MP)为研究对象,探究不同浓度(6、30、150、300μmol/g)绿原酸(Chlorogenic Acid,CA)与MP相互作用的结构变化及结合性质。在25℃下孵育形成不同CA-MP复合物,通过测定复合物的理化性质(总巯基,表面疏水性),二级,三级结构变化(傅里叶红外光谱、同步荧光、三维荧光),结合性质(紫外光谱,荧光猝灭及热力学参数)分析CA-MP复合物相互作用情况。结果表明,在300μmol/g CA存在下,蛋白总巯基含量和表面疏水性分别骤降25.65%,40.26%(P<0.05);蛋白质二级结构随之展开,α-螺旋含量下降至11.73%,造成蛋白结构稳定性降低;同步荧光与三维荧光光谱表明CA对蛋白荧光具有猝灭作用,且色氨酸比酪氨酸的猝灭效果高7.90%。紫外光谱和荧光猝灭证实CA-MP形成复合物且二者的结合为静态猝灭,热力学参数进一步验证二者相互作用的主导力为疏水作用力。本研究旨在为多酚与高白鲑MP相互作用提供有价值的信息,为后续对不同结构多酚与高白鲑肌球蛋白的相互作用机制提供研究基础。 展开更多
关键词 绿原酸 肌原纤维蛋白 相互作用 多光谱学 蛋白结构
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Analysis of rice paper's morphological features based on multispectral imaging technology
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作者 何少岩 陈舜儿 +1 位作者 翟浩田 刘伟平 《Journal of Measurement Science and Instrumentation》 CAS 2014年第4期46-51,共6页
Computer forensics and identification for traditional Chinese painting arts have caught the attention of various fields. Rice paper's feature extraction and analysis methods are of high significance for the rice pape... Computer forensics and identification for traditional Chinese painting arts have caught the attention of various fields. Rice paper's feature extraction and analysis methods are of high significance for the rice paper is an important carrier of traditional Chinese painting arts. In this paper, rice paper's morphological feature analysis is done using multi spectral imaging technology. The multispectral imaging system is utilized to acquire rice paper's spectral images in different wave- length channels, and then those spectral images are measured using texture parameter statistics to acquire sensitive bands for rice paper's feature. The mathematical morphology and grayscale statistical principle are utilized to establish a rice paper's morphological feature analytical model which is used to acquire rice paper' s one-dimensional vector. For the purpose of eval- uating these feature vectors' accuracy, they are entered into the support vector machine(SVM) classifier for detection and classification. The results show that the rice paper's feature is out loud in the spectral band 550 nm, and the average classifi- cation accuracy of feature vectors output from the analytical model is 96 %. The results indicate that the rice paper's feature analytical model can extract most of rice paper's features with accuracy and efficiency. 展开更多
关键词 rice paper multispectral imaging texture analysis mathematical morphology
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Semi-supervised kernel FCM algorithm for remote sensing image classification
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作者 刘小芳 HeBinbin LiXiaowen 《High Technology Letters》 EI CAS 2011年第4期427-432,共6页
These problems of nonlinearity, fuzziness and few labeled data were rarely considered in traditional remote sensing image classification. A semi-supervised kernel fuzzy C-means (SSKFCM) algorithm is proposed to over... These problems of nonlinearity, fuzziness and few labeled data were rarely considered in traditional remote sensing image classification. A semi-supervised kernel fuzzy C-means (SSKFCM) algorithm is proposed to overcome these disadvantages of remote sensing image classification in this paper. The SSKFCM algorithm is achieved by introducing a kernel method and semi-supervised learning technique into the standard fuzzy C-means (FCM) algorithm. A set of Beijing-1 micro-satellite's multispectral images are adopted to be classified by several algorithms, such as FCM, kernel FCM (KFCM), semi-supervised FCM (SSFCM) and SSKFCM. The classification results are estimated by corresponding indexes. The results indicate that the SSKFCM algorithm significantly improves the classification accuracy of remote sensing images compared with the others. 展开更多
关键词 remote sensing image classification semi-supervised kernel fuzzy C-means (SSKFCM)algorithm Beijing-1 micro-satellite semi-supcrvisod learning tochnique kernel method
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EPR and DFT Study of the Polycyclic Aromatic Radical Cations from Friedel-Crafts Alkylation Reactions
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作者 Tao Wang An-an Wu +1 位作者 Li-guo Gao Han-qing Wang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第1期51-56,共6页
Electron paramagnetic resonance and electron-nuclear double resonance methods were used to study the polycyclic aromatic radical cations produced in a Friedel-Crafts alkylating sys- tem, with m-xylene, or p-xylene and... Electron paramagnetic resonance and electron-nuclear double resonance methods were used to study the polycyclic aromatic radical cations produced in a Friedel-Crafts alkylating sys- tem, with m-xylene, or p-xylene and alkyl chloride. The results indicate that the observed electron paramagnetic resonance spectra are due to polycyclic aromatic radicals formed from the parent hydrocarbons. It is suggested that benzyl halides produced in the Friedel-Crafts alkylation reactions undergo Scholl self-condensation to give polycyclic aromatic hydrocar- bons, which are converted into corresponding polycyclic aromatic radical cations in the presence of AlCl3. The identification of observed two radicals 2,6-dimethylanthracene and 1,4,5,8-tetramethylanthraeene were supported by density functional theory calculations using the B3LYP/6-31G(d,p)//B3LYP/6-31G(d) approach. The theoretical coupling constants support the experimental assignment of the observed radicals. 展开更多
关键词 Electron paramagnetic resonance Eelectron-nuclear double resonance Density functional theory Polycyclic aromatic radical cation
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A Highly Sensitive Femtosecond Time-Resolved Sum Frequency Generation Vibrational Spectroscopy System with Simultaneous Measurement of Multiple Polarization Combinations 被引量:2
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作者 谈军军 罗毅 叶树集 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第6期671-677,I0002,共8页
Characterization of real-time and ultrafast motions of the complex molecules at surface and interface is critical to understand how interracial molecules function. It requires to develop surface-sensitive, fast-identi... Characterization of real-time and ultrafast motions of the complex molecules at surface and interface is critical to understand how interracial molecules function. It requires to develop surface-sensitive, fast-identification, and time-resolved techniques. In this study, we employ several key technical procedures and successfully develop a highly sensitive femtosecond time-resolved sum frequency generation vibrational spectroscopy (SFG-VS) system. This system is able to measure the spectra with two polarization combinations (ssp and ppp, or psp and ssp) simultaneously. It takes less than several seconds to collect one spectrum. To the best of our knowledge, it is the fastest speed of collecting SFG spectra reported by now. Using the time-resolved measurement, ultrafast vibrational dynamics of the N-H mode of α-helical peptide at water interface is determined. It is found that the membrane environment does not affect the N-H vibrational relaxation dynamics. It is expected that the time-resolved SFG system will play a vital role in the deep understanding of the dynamics and interaction of the complex molecules at surface and interface. Our method may also provide an important technical proposal for the people who plan to develop time-resolved SFG systems with simultaneous measurement of multiple polarization combinations. 展开更多
关键词 Femtosecond time-resolved Sum frequency generation vibrational spectroscopy Ultrafast vibrational dynamics Multiple polarization combination measurement CHIRAL
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Optical and electrical properties of blue-light polyfluorence/porous silicon composites
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作者 钟福如 石伟 +1 位作者 吕小毅 贾振红 《Optoelectronics Letters》 EI 2011年第2期133-135,共3页
Optical and electrical properties of composites formed by mixing porous silicon (PS) and poly (9, 9- diocty-2, 7-fluorene- co-4, 4'-butoxydiphenyl) (PFP) have been studied by Fourier transform-infrared spectros... Optical and electrical properties of composites formed by mixing porous silicon (PS) and poly (9, 9- diocty-2, 7-fluorene- co-4, 4'-butoxydiphenyl) (PFP) have been studied by Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The optical spectra show that porous silicon is incorporated into the polymer without significant change in the polymer properties. The FT-IR spectroscopy has detected the existence of specific interactions, which may be attributed to non-conjugated alkoxy segment. By fitting the current-voltage (/-V) curve of PFP/PS structure with the modified standard ecluation, the n factor and I0 are cletermined 展开更多
关键词 Curve fitting Fourier transforms Infrared spectroscopy Photoluminescence spectroscopy Porous silicon Scanning electron microscopy
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