期刊文献+
共找到47,686篇文章
< 1 2 250 >
每页显示 20 50 100
In situ infrared, Raman and X-ray spectroscopy for the mechanistic understanding of hydrogen evolution reaction
1
作者 Andi Haryanto Kyounghoon Jung +1 位作者 Chan Woo Lee Dong-Wan Kim 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期632-651,I0014,共21页
Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy future.Computational methods have been widely use... Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy future.Computational methods have been widely used to study the reaction mechanism of the hydrogen evolution reaction(HER),but the calculation results need to be supported by experimental results and direct evidence to confirm the mechanistic insights.In this review,we discuss the fundamental principles of the in situ spectroscopic strategy and a theoretical model for a mechanistic understanding of the HER.In addition,we investigate recent studies by in situ Fourier transform infrared(FTIR),Raman spectroscopy,and X-ray absorption spectroscopy(XAS) and cover new findings that occur at the catalyst-electrolyte interface during HER.These spectroscopic strategies provide practical ways to elucidate catalyst phase,reaction intermediate,catalyst-electrolyte interface,intermediate binding energy,metal valency state,and coordination environment during HER. 展开更多
关键词 Hydrogen evolution reaction Infrared spectroscopy raman spectroscopy X-ray absorption spectroscopy Reaction mechanism
下载PDF
Rapid analysis of Chinese steamed bread staling using Raman Spectroscopy
2
作者 Tong Sang Yong-Hui Yu Xiao-Dan Liu 《Food and Health》 2024年第3期42-47,共6页
Staling is an important issue that Chinese steamed bread(CSB)may encounter during storage,which significantly affects their taste,flavor,and nutritional value.The monitoring technology for rapid aging is particularly ... Staling is an important issue that Chinese steamed bread(CSB)may encounter during storage,which significantly affects their taste,flavor,and nutritional value.The monitoring technology for rapid aging is particularly important to effectively control the aging process of CSB,reduce quality deterioration,and promote the industrial production of CSB.Raman spectroscopy has been widely used in the study of food structure and properties due to its non-destructive and high-sensitivity characteristics,particularly demonstrating unique advantages in the analysis of starch structure.This study explored the possibility of analyzing the staling of CSB using Raman spectroscopy based on hardness and moisture content.Analysis of the correlation between the hardness of CSB and the full width at half maximum(FWHM)at 480 cm^(−1)during storage was conducted,and a significant positive correlation between them was found,with R^(2)above 0.8.Besides,nine characteristic peaks of CSB samples related to starch were selected for analysis.As the moisture content of CSB decreased,the peak intensities and areas of showed an upward trend during storage,with the best correlation coefficient above 0.8 revealed by linear regression analysis.Therefore,Raman spectra could be used as a potential method for the fast prediction of CSB staling. 展开更多
关键词 Chinese steamed bread STALING HARDNESS moisture content raman spectroscopy
下载PDF
The Fabrication and Detection Performance of High Sensitivity Au-Ag Alloy Nanostar/Paper Flexible Surface Enhanced Raman Spectroscopy Sensors
3
作者 邓芷盈 WANG Tianyi +4 位作者 CAO Shiyi ZHAO Yuan HAN Xiaoyu 张继红 谢俊 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期436-443,共8页
Au-Ag alloy nanostars based flexible paper surface enhanced Raman spectroscopy sensors were fabricated through simple nanostar coating on regular office paper,and the surface enhanced Raman spectroscopy detection perf... Au-Ag alloy nanostars based flexible paper surface enhanced Raman spectroscopy sensors were fabricated through simple nanostar coating on regular office paper,and the surface enhanced Raman spectroscopy detection performances were investigated using crystal violet dye analyte.Au-Ag nanostars with sharp tips were synthesized via metal ions reduction method.Transmission electron microscope images,X-Ray diffraction pattern and energy dispersive spectroscopy elemental mapping confirmed the nanostar geometry and Au/Ag components of the nanostructure.UV-Vis-NIR absorption spectrum shows wide local surface plasmon resonance induced optical extinction.In addition,finite-difference time-domain simulation shows much stronger electromagnetic field from nanostars than from sphere nanoparticle.The effect of coating layer on Raman signal intensities was discussed,and optimized 5-layer coating with best Raman signal was obtained.The Au-Ag nanostatrs homogeneously distribute on paper fiber surface.The detection limit is 10-10 M,and the relationship between analyte concentrations and Raman signal intensities shows well linear,for potential quantitative analysis.The calculated enhancement factor is 4.795×10^(6).The flexible paper surface enhanced Raman spectroscopy sensors could be applied for trace chemical and biology molecule detection. 展开更多
关键词 surface-enhanced raman gold-silver alloy nanostars paper-based SERS sensor FLEXIBILITY
下载PDF
Exploring the Cation Regulation Mechanism for Interfacial Water Involved in the Hydrogen Evolution Reaction by In Situ Raman Spectroscopy
4
作者 Xueqiu You Dongao Zhang +4 位作者 Xia‑Guang Zhang Xiangyu Li Jing‑Hua Tian Yao‑Hui Wang Jian‑Feng Li 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期303-312,共10页
Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.U... Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.Unfortunately,investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.Here,the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry,in situ core-shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques.Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction.When comparing the different cation electrolyte systems at a given potential,the frequency of the interfacial water peak increases in the specified order:Li+<Na^(+)<K^(+)<Ca^(2+)<Sr^(2+).The structure of interfacial water was optimized by adjusting the radius,valence,and concentration of cation to form the two-H down structure.This unique interfacial water structure will improve the charge transfer efficiency between the water and electrode further enhancing the HER performance.Therefore,local cation tuning strategies can be used to improve the HER performance by optimizing the interfacial water structure. 展开更多
关键词 In situ raman Interfacial water Hydrogen evolution reaction CATIONS
下载PDF
Assessment of portable FTIR and Raman spectroscopy for the detection of 2,3-dimethyl-2,3-dinitrobutane(DMDNB)in plastic explosives
5
作者 Jacky Cailes Robert Dunsmore Kathryn L.Linge 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期11-18,共8页
The Marplex Convention was established to prevent the manufacture of unmarked plastic explosives and stipulates that a volatile detection agent must be added at the time of manufacture.However,to-date,laboratory testi... The Marplex Convention was established to prevent the manufacture of unmarked plastic explosives and stipulates that a volatile detection agent must be added at the time of manufacture.However,to-date,laboratory testing remains the internationally accepted practice for identifying and quantifying the taggants stipulated in the Convention.In this project,portable FTIR and Raman instruments were tested for their ability to detect 2,3-dimethyl-2,3-dinitrobutane(DMDNB),the chemical marker incorporated in plastic explosives that are manufactured within Australia.While both FTIR and Raman instruments detected solid DMDNB(98%purity),field analysis of plastic explosives at an Australian Defence establishment showed that both FTIR and Raman spectra were matched the relevant explosive(RDX or PETN),rather than the DMDNB taggant.For all three plastic explosives tested,the concentration of DMDNB was measured by SPME-GC-MS to be between 1.8 and 2%,greater than the minimum 1%concentration stipulated by the Marplex Convention.Additional testing with a plastic explosive analogue confirmed that the minor absorption peaks that would characterize low concentrations of DMDNB were masked by absorption bands from other compounds within the solid.Thus,while both FTIR and Raman spectroscopy are suitable for detection of plastic explosives,neither rely on the presence of DMDNB for detection.It is likely that similar results would be found for other taggants stipulated by the Marplex Convention,given they are also present in concentrations less than 1%. 展开更多
关键词 Explosive ICAO taggants 2 3-Dimethyl-2 3-dinitrobutane(DMDNB) Fourier transform infrared(FTIR) raman
下载PDF
基于Raman光谱的3,5-二氨基-1,2,4-三唑(DAT)合成反应在线监测与反应机理探究——推荐一个仪器分析综合实验
6
作者 张天龙 张容玲 +2 位作者 汤宏胜 李延 李华 《大学化学》 CAS 2024年第6期303-311,共9页
本实验介绍了一个仪器分析综合性实验——基于Raman光谱的3,5-二氨基-1,2,4-三唑(DAT)合成的在线监测与反应机理探究。该实验是一个科研转化的仪器分析综合实验,内容包括DAT的合成、基于Raman光谱的合成反应过程在线监测以及合成反应机... 本实验介绍了一个仪器分析综合性实验——基于Raman光谱的3,5-二氨基-1,2,4-三唑(DAT)合成的在线监测与反应机理探究。该实验是一个科研转化的仪器分析综合实验,内容包括DAT的合成、基于Raman光谱的合成反应过程在线监测以及合成反应机理解析。在实验中,采用化学计量学方法对Raman光谱数据进行处理和分析,以更深入地理解合成反应的机理。通过本实验,可以巩固学生的化学专业知识,提高学生的综合实验操作技能,激发学生对科学研究的兴趣,培养学生的科研探究能力。 展开更多
关键词 拉曼光谱 在线监测 合成反应机理 综合实验
下载PDF
基于Raman的复方柳安咖注射液主要成分分析
7
作者 张川云 李伦 +2 位作者 司民真 徐选盼 张德清 《光散射学报》 北大核心 2024年第2期122-133,共12页
本文应用拉曼光谱技术对复方柳安咖注射液的主要成分及含量进行了分析。首先测试分析了62个复方柳安咖注射液样品的拉曼光谱,结果表明62个注射液样品的拉曼光谱主要由水杨酸钠、安替比林和咖啡因的水溶液拉曼谱带组成;进一步利用密度泛... 本文应用拉曼光谱技术对复方柳安咖注射液的主要成分及含量进行了分析。首先测试分析了62个复方柳安咖注射液样品的拉曼光谱,结果表明62个注射液样品的拉曼光谱主要由水杨酸钠、安替比林和咖啡因的水溶液拉曼谱带组成;进一步利用密度泛函理论(DFT)计算了其主要成分的理论拉曼光谱和红外光谱,与实验测定的固体粉末光谱和溶液光谱进行比较分析,进而对复方柳安咖注射液拉曼光谱谱峰的振动模式进行了归属;最后利用水杨酸钠和安替比林浓度梯度溶液拉曼光谱特征峰的峰高和峰面积,分别建立定量分析模型,对62个复方柳安咖注射液样品中主要成分水杨酸钠和安替比林的含量进行预测,并与液相色谱法测试值进行了对比,结果显示预测值与液相色谱法测试值相近,得到了较好的主要成分含量预测结果。研究结果可为复方柳安咖注射液药剂的生产、药品质量的监控、药品光谱分析研究等方面提供参考。 展开更多
关键词 拉曼光谱 复方柳安咖注射液 密度泛函理论 定量分析
下载PDF
盐湖卤水中硼酸盐化学形态及Raman光谱定量分析
8
作者 彭姣玉 杨克利 +3 位作者 董亚萍 冯海涛 张波 李武 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第9期2514-2522,共9页
我国青藏盐湖以富含硼锂而著称,卤水中硼化学赋存状态随湖水化学类型的不同而发生变化,其中以硫酸盐型盐湖卤水中硼酸盐的存在形式变化最为复杂,卤水蒸发过程一般不以固体盐形式结晶析出,而是以多硼物种形式富集于氯化镁饱和老卤中,表... 我国青藏盐湖以富含硼锂而著称,卤水中硼化学赋存状态随湖水化学类型的不同而发生变化,其中以硫酸盐型盐湖卤水中硼酸盐的存在形式变化最为复杂,卤水蒸发过程一般不以固体盐形式结晶析出,而是以多硼物种形式富集于氯化镁饱和老卤中,表现出严重的过饱和性,对后续锂盐和镁盐的分离提取影响较大。开展盐湖卤水体系中硼酸盐化学形态、分布规律及离子间作用机制等溶液化学研究对盐湖资源高效开发具有重要的意义。相比常规拉曼光谱技术,拉曼积分球基于拉曼散射原理可极大地提高激发光的使用效率和拉曼散射信号,对硼酸盐溶液结构检测具有拉曼响应信号强、检出限低、信噪比高等优点,为盐卤复杂体系硼酸盐化学形态的定量分析奠定了基础。利用拉曼积分球开展了盐湖卤水硼酸盐化学形态研究,阐述了卤水蒸发过程多硼酸根离子的变化规律;同时借助响应曲面法进行实验设计与优化,建立了共存盐类干扰回归模型用于盐湖卤水中单硼物种B(OH)_(3)的准确测定。结果表明,盐湖卤水浓缩过程中硼不断聚合生成多聚度硼酸根离子如B3O3(OH)-4和B_(6)O_(7)(OH)2-7等,硼的化学形态变化规律与碱土金属如MgCl_(2)-MgO-2B_(2)O_(3)-H_(2)O体系中硼物种变化一致,但与碱金属溶液体系物种变化差别较大。回归模型对卤水中正硼酸B(OH)_(3)定量分析的相对误差小于5%,准确度较高;阐明了蒸发浓缩过程中B(OH)_(3)物种分布的变化规律,从定量视角初步阐述了卤水富集过程硼酸根离子间的聚合作用关系,可为后续开展盐卤体系多硼物种分布及作用机制研究提供新思路、新方法。 展开更多
关键词 卤水 硼酸盐:响应曲面 拉曼光谱 定量分析
下载PDF
Quantification of radiation damage in natural and synthetic zircon by Raman spectroscopy:application to low-temperature thermochronology
9
作者 Ke Su Shao-Bing Zhang +4 位作者 John MHanchar Zhen-Xin Li Fang-Yuan Sun Ting Liang Xiao-Ying Gao 《Acta Geochimica》 EI CAS CSCD 2023年第4期673-688,共16页
Due to its ubiquitous occurrence in igneous,metamorphic,and sedimentary rocks and its wide application in geochronology and geochemistry,zircon has become the most widely used accessory mineral in the geological commu... Due to its ubiquitous occurrence in igneous,metamorphic,and sedimentary rocks and its wide application in geochronology and geochemistry,zircon has become the most widely used accessory mineral in the geological community.Nevertheless,the decay of U and Th causes radiation damage to the zircon structure,resulting in various degrees of metamictization,which can affect the accuracy of U–Pb dates and Hf and O isotope results.If the degree of zircon radiation damage can be quantified,the influence on geochemical analyses can be evaluated,and the results can be corrected more precisely.In this paper,synthetic and natural zircon crystals with different crystallization ages were selected for Raman spectroscopy analysis,cathodoluminescence imaging,and determination of the U and Th concentrations.The results show that Raman FWHM(full width at half bandmaximum)and Raman shift correlate with alpha dose(Da)ofzirconsfollowingtheseequations,FWHM=44.36(±2.32)×[1-exp(-2.74×Da)]-+1.7(±0.19),Raman Shift=-6.53×Da+1007.69.Analysis of synthetic zircon crystals shows that doped REEs(rare earth elements and P)can also lead to an increase in the FWHM.However,this effect can be ignored for natural zircon samples with REE contents at a normal level of hundreds to a few thousand ppm.The FWHM and Raman shift can be used as proxies to measure the degree of zircon radiation damage.Using the updated equations to calculate the latest age when zircon began to accumulate radiation damage,a more accurate and more meaningful“radiation damage age”can be obtained. 展开更多
关键词 ZIRCON Radiation damage raman spectroscopy FWHM(full width at half-maximum) raman shift raman isochron age
下载PDF
Determination of esophageal squamous cell carcinoma and gastric adenocarcinoma on raw tissue using Raman spectroscopy
10
作者 Hiroaki Ito Naoyuki Uragami +13 位作者 Tomokazu Miyazaki Yuto Shimamura Haruo Ikeda Yohei Nishikawa Manabu Onimaru Kai Matsuo Masayuki Isozaki William Yang Kenji Issha Satoshi Kimura Machiko Kawamura Noboru Yokoyama Miki Kushima Haruhiro Inoue 《World Journal of Gastroenterology》 SCIE CAS 2023年第20期3145-3156,共12页
BACKGROUND Cancer detection is a global research focus,and novel,rapid,and label-free techniques are being developed for routine clinical practice.This has led to the development of new tools and techniques from the b... BACKGROUND Cancer detection is a global research focus,and novel,rapid,and label-free techniques are being developed for routine clinical practice.This has led to the development of new tools and techniques from the bench side to routine clinical practice.In this study,we present a method that uses Raman spectroscopy(RS)to detect cancer in unstained formalin-fixed,resected specimens of the esophagus and stomach.Our method can record a clear Raman-scattered light spectrum in these specimens,confirming that the Raman-scattered light spectrum changes because of the histological differences in the mucosal tissue.AIM To evaluate the use of Raman-scattered light spectrum for detecting endoscopically resected specimens of esophageal squamous cell carcinoma(SCC)and gastric adenocarcinoma(AC).METHODS We created a Raman device that is suitable for observing living tissues,and attempted to acquire Raman-scattered light spectra in endoscopically resected specimens of six esophageal tissues and 12 gastric tissues.We evaluated formalin-fixed tissues using this technique and captured shifts at multiple locations based on feasibility,ranging from six to 19 locations 200 microns apart in the vertical and horizontal directions.Furthermore,a correlation between the obtained Raman scattered light spectra and histopathological diagnosis was performed.RESULTS We successfully obtained Raman scattered light spectra from all six esophageal and 12 gastric specimens.After data capture,the tissue specimens were sent for histopathological analysis for further processing because RS is a label-free methodology that does not cause tissue destruction or alterations.Based on data analysis of molecular-level substrates,we established cut-off values for the diagnosis of esophageal SCC and gastric AC.By analyzing specific Raman shifts,we developed an algorithm to identify the range of esophageal SCC and gastric AC with an accuracy close to that of histopathological diagnoses.CONCLUSION Our technique provides qualitative information for real-time morphological diagnosis.However,further in vivo evaluations require an excitation light source with low human toxicity and large amounts of data for validation. 展开更多
关键词 raman spectroscopy Squamous cell carcinoma ADENOCARCINOMA ESOPHAGUS STOMACH Labelfree cancer detection Real-time diagnosis
下载PDF
Recent advances in Raman spectroscopy for skin diagnosis
11
作者 Min Wu Beibei Gao Xunbin Wei 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2023年第3期13-31,共19页
The skin is the largest organ in humans.It comprises about 16%of our body.Many diseases originate from the skin,including acne vulgaris,skin cancer,fungal skin disease,etc.As a common skin cancer in China,melanoma alo... The skin is the largest organ in humans.It comprises about 16%of our body.Many diseases originate from the skin,including acne vulgaris,skin cancer,fungal skin disease,etc.As a common skin cancer in China,melanoma alone grows at year rate of nearly 4%.Therefore,it is crucial to develop an objective,reliable,accurate,non-invasive,and easy-to-use diagnostic method for skin diseases to support clinical decision-making.Raman spectroscopy is a highly specic imaging technique,which is sensitive,even to the single-cell level in skin diagnosis.Raman spectroscopy provides a pattern of signals with narrow bandwidths,making it a common and essential tool for researching individual characteristics of skin cells.Raman spectroscopy already has a number of clinical applications,including in thyroid,cervical and colorectal cancer.This review will introduce the advantages and recent developments in Raman spectroscopy,before focusing on the advances in skin diagnosis,including the advantages,methods,results,analysis,and notications.Finally,we discuss the current limitations and future progress of Raman spectroscopy in the context of skin diagnosis. 展开更多
关键词 raman spectroscopy skin diagnosis raman imaging MELANOMA
下载PDF
Unveiling localized electronic properties of ReS2 thin layers at nanoscale using Kelvin force probe microscopy combined with tip-enhanced Raman spectroscopy
12
作者 罗宇 苏伟涛 +4 位作者 张娟娟 陈飞 武可 曾宜杰 卢红伟 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期598-603,共6页
Electronic properties of two-dimensional(2D) materials can be strongly modulated by localized strain. The typical spatial resolution of conventional Kelvin probe force microscopy(KPFM) is usually limited in a few hund... Electronic properties of two-dimensional(2D) materials can be strongly modulated by localized strain. The typical spatial resolution of conventional Kelvin probe force microscopy(KPFM) is usually limited in a few hundreds of nanometers, and it is difficult to characterize localized electronic properties of 2D materials at nanoscales. Herein, tip-enhanced Raman spectroscopy(TERS) is proposed to combine with KPFM to break this restriction. TERS scan is conducted on ReS2bubbles deposited on a rough Au thin film to obtain strain distribution by using the Raman peak shift. The localized contact potential difference(CPD) is inversely calculated with a higher spatial resolution by using strain measured by TERS and CPD-strain working curve obtained using conventional KPFM and atomic force microscopy. This method enhances the spatial resolution of CPD measurements and can be potentially used to characterize localized electronic properties of 2D materials. 展开更多
关键词 few layer ReS2 tip enhanced raman spectroscopy local strain Kelvin probe force microscopy
下载PDF
Accurate quantification of TiO_(2)(B)'s phase purity via Raman spectroscopy
13
作者 Jiamiao Ran Hui Liu +8 位作者 Hongliang Dong Peng Gao Haowei Cheng Jianing Xu Hailun Wang Zixing Wang Qingfeng Fu Jiaxu Yan Jilei Liu 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第5期1371-1379,共9页
Bronze phase titanium dioxide(TiO_(2)(B))could be a promising high-power anode for lithium ion battery.However,TiO_(2)(B)is a metastable material,so the as-synthesized samples are inevitably accompanied by the existen... Bronze phase titanium dioxide(TiO_(2)(B))could be a promising high-power anode for lithium ion battery.However,TiO_(2)(B)is a metastable material,so the as-synthesized samples are inevitably accompanied by the existence of anatase phases.It has been found that the TiO_(2)(B)'s purity is positively correlated with its electrochemical performance.Herein,we have established an accurate quantification of the TiO_(2)(B)/anatase ratio,by figuring out the function between the purity of TiO_(2)(B)phase in the high purity range and its Raman spectra features in combination of the calibration by the synchrotron radiation X-ray diffraction(XRD).Compared with the time-consuming electrochemical method,the rapid,sensitive and non-destructive features of Raman spectroscopy have made it a promising candidate for determining the purity of TiO_(2)(B).Further,the correlations developed in this work should be instructive in synthesizing pure TiO_(2)(B)and furthermore optimizing its electrochemical charge storage properties. 展开更多
关键词 TiO_(2)(B) Phase purity raman spectroscopy Synchrotron XRD Charge storage properties
下载PDF
Reconstructing in vivo spatially offset Raman spectroscopy of human skin tissue using a GPU-accelerated Monte Carlo platform
14
作者 张云鹤 朱桓正 +6 位作者 董泳江 曾佳 韩新鹏 Ivan A.Bratchenko 张富荣 许思源 王爽 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期140-150,共11页
As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering du... As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering during in vivo inverse SORS measurements, the light–tissue interactions when excitation and regenerated Raman photons propagate in skin tissue were studied using Monte Carlo simulation. An eight-layered skin model was first built based on the latest transmission parameters. Then, an open-source platform, Monte Carlo e Xtreme(MCX), was adapted to study the distribution of 785 nm excitation photons inside the model with an inverse spatially shifted annular beam. The excitation photons were converted to emission photons by an inverse distribution method based on excitation flux with spatial offsets Δs of 1 mm, 2 mm, 3 mm and 5 mm. The intrinsic Raman spectra from separated skin layers were measured by continuous linear scanning to improve the simulation accuracy. The obtained results explain why the spectral detection depth gradually increases with increasing spatial offset, and address how the intrinsic Raman spectrum from deep skin layers is distorted by the reabsorption and scattering of the superficial tissue constituents. Meanwhile, it is demonstrated that the spectral contribution from subcutaneous fat will be improved when the offset increases to 5 mm, and the highest detection efficiency for dermal layer spectral detection could be achieved when Δs = 2 mm. Reasonably good matching between the calculated spectrum and the measured in vivo inverse SORS was achieved, thus demonstrating great utility of our modeling method and an approach to help understand the clinical measurements. 展开更多
关键词 Monte Carlo simulation tissue optical model spatially offset raman spectroscopy
下载PDF
Facile electrochemical surface-alloying and etching of Au wires to enable high-performance substrates for surface enhanced Raman scattering
15
作者 Yawen Zhan Guobin Zhang +8 位作者 Junda Shen Binbin Zhou Chenghao Zhao Junmei Guo Ming Wen Zhilong Tan Lirong Zheng Jian Lu Yang Yang Li 《Nano Materials Science》 EI CAS CSCD 2024年第3期305-311,共7页
Surface-enhanced Raman Spectroscopy(SERS)is a nondestructive technique for rapid detection of analytes even at the single-molecule level.However,highly sensitive and reliable SERS substrates are mostly fabricated with... Surface-enhanced Raman Spectroscopy(SERS)is a nondestructive technique for rapid detection of analytes even at the single-molecule level.However,highly sensitive and reliable SERS substrates are mostly fabricated with complex nanofabrication techniques,greatly restricting their practical applications.A convenient electrochemical method for transforming the surface of commercial gold wires/foils into silver-alloyed nanostructures is demonstrated in this report.Au substrates are treated with repetitive anodic and cathodic bias in an electrolyte of thiourea,in a one-pot one-step manner.X-rays absorption fine structure(XAFS)spectroscopy confirms that the AuAg alloy is induced at the surface.The unique AuAg alloyed surface nanostructures are particularly advantageous when served as SERS substrates,enabling a remarkably sensitive detection of Rhodamine B(a detection limit of 10^(-14)M,and uniform strong response throughout the substrates at 10^(-12)M). 展开更多
关键词 ELECTRODEPOSITION DEALLOYING Surface-alloyed Noble metals Surface enhanced raman spectroscopy substrates
下载PDF
Real-time model correction using Kalman filter for Raman-controlled cell culture processes
16
作者 Xiaoxiao Dong Zhuohong He +5 位作者 Xu Yan Dong Gao Jingyu Jiao Yan Sun Haibin Wang Haibin Qu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期251-260,共10页
Raman spectroscopy has found extensive use in monitoring and controlling cell culture processes.In this context,the prediction accuracy of Raman-based models is of paramount importance.However,models established with ... Raman spectroscopy has found extensive use in monitoring and controlling cell culture processes.In this context,the prediction accuracy of Raman-based models is of paramount importance.However,models established with data from manually fed-batch cultures often exhibit poor performance in Raman-controlled cultures.Thus,there is a need for effective methods to rectify these models.The objective of this paper is to investigate the efficacy of Kalman filter(KF)algorithm in correcting Raman-based models during cell culture.Initially,partial least squares(PLS)models for different components were constructed using data from manually fed-batch cultures,and the predictive performance of these models was compared.Subsequently,various correction methods including the PLS-KF-KF method proposed in this study were employed to refine the PLS models.Finally,a case study involving the auto-control of glucose concentration demonstrated the application of optimal model correction method.The results indicated that the original PLS models exhibited differential performance between manually fed-batch cultures and Raman-controlled cultures.For glucose,the root mean square error of prediction(RMSEP)of manually fed-batch culture and Raman-controlled culture was 0.23 and 0.40 g·L^(-1).With the implementation of model correction methods,there was a significant improvement in model performance within Raman-controlled cultures.The RMSEP for glucose from updating-PLS,KF-PLS,and PLS-KF-KF was 0.38,0.36 and 0.17 g·L^(-1),respectively.Notably,the proposed PLS-KF-KF model correction method was found to be more effective and stable,playing a vital role in the automated nutrient feeding of cell cultures. 展开更多
关键词 raman spectroscopy Model correction Algorithm Model-predictive control BIOPROCESS
下载PDF
Vibrational Spectroscopy of Pain Relievers: Traditional and Remote Raman Techniques
17
作者 Aschalew Kassu Damoni Robinson 《Journal of Analytical Sciences, Methods and Instrumentation》 2023年第3期27-37,共11页
The application of vibrational spectroscopy in the pharmaceutical industry is widely investigated, from the quality assurance of the product during the production process control to the final products’ quality contro... The application of vibrational spectroscopy in the pharmaceutical industry is widely investigated, from the quality assurance of the product during the production process control to the final products’ quality control and the authentication of products on the markets. This study focuses on non-contact and noninvasive detection and identification of pain-relievers at 1-5 meters standoff distances. The specimens analyzed include standard laboratory-grade active ingredients and commercially available pain relievers in powder, solid and liquid forms. All the remote measurements captured revealed the Raman signatures of the specimens, with varying peak intensities. To correlate the band intensities captured with the standoff distances between the laser source and the specimens, the intensity ratios of the two prominent peaks of the laboratory grade reference active ingredient (1607 and 1319 cm<sup>-1</sup>) normalized with 1319 cm<sup>-1</sup> are used. The results of the study suggest the viability of standoff Raman spectroscopy for routine monitoring and identification of pharma-ceuticals, including counterfeit pain relievers. 展开更多
关键词 raman spectroscopy ACETAMINOPHEN ASPIRIN Standoff raman Vibrational spectroscopy Pain Relievers
下载PDF
A core-satellite self-assembled SERS aptasensor containing a“biological-silent region”Raman tag for the accurate and ultrasensitive detection of histamine
18
作者 Chen Chen Yingfang Zhang +3 位作者 Ximo Wang Xuguang Qiao Geoffrey I.N.Waterhouse Zhixiang Xu 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期1029-1039,共11页
Herein,a novel interference-free surface-enhanced Raman spectroscopy(SERS)strategy based on magnetic nanoparticles(MNPs)and aptamer-driven assemblies was proposed for the ultrasensitive detection of histamine.A core-s... Herein,a novel interference-free surface-enhanced Raman spectroscopy(SERS)strategy based on magnetic nanoparticles(MNPs)and aptamer-driven assemblies was proposed for the ultrasensitive detection of histamine.A core-satellite SERS aptasensor was constructed by combining aptamer-decorated Fe_(3)O_(4)@Au MNPs(as the recognize probe for histamine)and complementary DNA-modified silver nanoparticles carrying 4-mercaptobenzonitrile(4-MBN)(Ag@4-MBN@Ag-c-DNA)as the SERS signal probe for the indirect detection of histamine.Under an applied magnetic field in the absence of histamine,the assembly gave an intense Raman signal at“Raman biological-silent”region due to 4-MBN.In the presence of histamine,the Ag@4-MBN@Ag-c-DNA SERS-tag was released from the Fe_(3)O_(4)@Au MNPs,thus decreasing the SERS signal.Under optimal conditions,an ultra-low limit of detection of 0.65×10^(-3)ng/mL and a linear range 10^(-2)-10^5 ng/mL on the SERS aptasensor were obtained.The histamine content in four food samples were analyzed using the SERS aptasensor,with the results consistent with those determined by high performance liquid chromatography.The present work highlights the merits of indirect strategies for the ultrasensitive and highly selective SERS detection of small biological molecules in complex matrices. 展开更多
关键词 Surface-enhanced raman spectroscopy raman biological-silent region Aptamer Histamine detection Universal SERS-tag
下载PDF
Raman spectroscopy in crop quality assessment: focusing on sensing secondary metabolites: a review
19
作者 Miri Park Annette Somborn +2 位作者 Dennis Schlehuber Volkmar Keuter Görge Deerberg 《Horticulture Research》 SCIE CSCD 2023年第5期282-296,共15页
As a crop quality sensor,Raman spectroscopy has been consistently proposed as one of the most promising and non-destructive methods for qualitative and quantitative analysis of plant substances,because it can measure ... As a crop quality sensor,Raman spectroscopy has been consistently proposed as one of the most promising and non-destructive methods for qualitative and quantitative analysis of plant substances,because it can measure molecular structures in a short time without requiring pretreatment along with simple usage.The sensitivity of the Raman spectrum to target chemicals depends largely on the wavelength,intensity of the laser power,and exposure time.Especially for plant samples,it is very likely that the peak of the target material is covered by strong fluorescence effects.Therefore,methods using lasers with low energy causing less fluorescence,such as 785 nm or near-infrared,are vigorously discussed.Furthermore,advanced techniques for obtaining more sensitive and clear spectra,like surface-enhanced Raman spectroscopy,time-gated Raman spectroscopy or combination with thin-layer chromatography,are being investigated.Numerous interpretations of plant quality can be represented not only by the measurement conditions but also by the spectral analysis methods.Up to date,there have been attempted to optimize and generalize analysis methods.This review summarizes the state of the art of micro-Raman spectroscopy in crop quality assessment focusing on secondary metabolites,from in vitro to in vivo and even in situ,and suggests future research to achieve universal application. 展开更多
关键词 spectroscopy qualitative LIKELY
下载PDF
Functional near-infrared spectroscopy in non-invasive neuromodulation 被引量:1
20
作者 Congcong Huo Gongcheng Xu +6 位作者 Hui Xie Tiandi Chen Guangjian Shao Jue Wang Wenhao Li Daifa Wang Zengyong Li 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1517-1522,共6页
Non-invasive cerebral neuromodulation technologies are essential for the reorganization of cerebral neural networks,which have been widely applied in the field of central neurological diseases,such as stroke,Parkinson... Non-invasive cerebral neuromodulation technologies are essential for the reorganization of cerebral neural networks,which have been widely applied in the field of central neurological diseases,such as stroke,Parkinson’s disease,and mental disorders.Although significant advances have been made in neuromodulation technologies,the identification of optimal neurostimulation paramete rs including the co rtical target,duration,and inhibition or excitation pattern is still limited due to the lack of guidance for neural circuits.Moreove r,the neural mechanism unde rlying neuromodulation for improved behavioral performance remains poorly understood.Recently,advancements in neuroimaging have provided insight into neuromodulation techniques.Functional near-infrared spectroscopy,as a novel non-invasive optical brain imaging method,can detect brain activity by measuring cerebral hemodynamics with the advantages of portability,high motion tole rance,and anti-electromagnetic interference.Coupling functional near-infra red spectroscopy with neuromodulation technologies offe rs an opportunity to monitor the cortical response,provide realtime feedbac k,and establish a closed-loop strategy integrating evaluation,feedbac k,and intervention for neurostimulation,which provides a theoretical basis for development of individualized precise neuro rehabilitation.We aimed to summarize the advantages of functional near-infra red spectroscopy and provide an ove rview of the current research on functional near-infrared spectroscopy in transcranial magnetic stimulation,transcranial electrical stimulation,neurofeedback,and braincomputer interfaces.Furthermore,the future perspectives and directions for the application of functional near-infrared spectroscopy in neuromodulation are summarized.In conclusion,functional near-infrared spectroscopy combined with neuromodulation may promote the optimization of central pellral reorganization to achieve better functional recovery form central nervous system diseases. 展开更多
关键词 brain-computer interface cerebral neural networks functional near-infrared spectroscopy neural circuit NEUROFEEDBACK neurological diseases NEUROMODULATION non-invasive brain stimulation transcranial electrical stimulation transcranial electrical stimulation
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部