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傅立叶红外光谱 1

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太赫兹时域光谱;微腔;金属孔阵列;波导腔;伪局域表面等离子体 1

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Cystine-assisted accumulation of gold nanoparticles on ZnO to construct a sensitive surface-enhanced Ramanspectroscopy substrate

《化学科学与工程前沿(英文)》 2023年 第17卷 第1期   页码 15-23 doi: 10.1007/s11705-022-2177-8

摘要: Recently, various semiconductor/metal composites have been developed to fabricate surface-enhanced Raman spectroscopy substrates. However, low metal loading on semiconductors is still a challenge. In this study, cystine was introduced to increase the accumulation of gold nanoparticles on zinc oxide, owing to the biomineralization property of cystine. Morphological analysis revealed that the obtained ZnO/Au/cystine composite not only had a higher metal loading but also formed a porous structure, which is beneficial for Raman performance. Compared with ZnO/Au, the ZnO/Au/cystine substrate displayed a 40-fold enhancement in the Raman signal and a lower limit of detection (10–11 mol·L−1) in the detection of rhodamine 6G. Moreover, the substrate has favorable homogeneity and stability. Finally, ZnO/Au/cystine displayed excellent performance toward crystal violet and methylene blue in a test based on river water samples. This study provided a promising method to fabricate sensitive semiconductor/noble metal-based surface-enhanced Raman spectroscopy substrates for Raman detection.

关键词: biomineralization     cystine     semiconductor/metal composite     SERS detection     Raman detection    

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

《结构与土木工程前沿(英文)》 2016年 第10卷 第2期   页码 168-173 doi: 10.1007/s11709-015-0323-9

摘要: In the present study, chemical mapping on the hydration process of cement paste with water-to-cement ( / ) ratio of 0.60 was implemented by Raman spectroscopy (RS). The RS was applied to study the paste from 12 hours after mixing to 28 days. Cement ingredients and hydration products, including calcium silicates (C S and C S), calcium hydroxide (CH), and ettringite, were quantitatively studied. From the research, it is observed that calcium silicates were consumed gradually with the increased hydration age. Calcium hydroxide increased and tended to cluster in the pore vicinity during hydration. Ettringite was found to form on the surface of the unreacted particles, which was shown as a mixed zone of ettringite and calcium silicates in the maps. It is concluded from the study that chemical mapping was an effective method to assist in visualizing particle dispersion and connection on top of the quantitative analysis.

关键词: chemical mapping     Raman spectroscopy     calcium silicates     calcium hydroxide     ettringite    

Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

《能源前沿(英文)》 2018年 第12卷 第1期   页码 43-71 doi: 10.1007/s11708-018-0524-8

摘要: Vibrational spectroscopy is one of the key instrumentations that provide non-invasive investigation of structural and chemical composition for both organic and inorganic materials. However, diffraction of light fundamentally limits the spatial resolution of far-field vibrational spectroscopy to roughly half the wavelength. In this article, we thoroughly review the integration of atomic force microscopy (AFM) with vibrational spectroscopy to enable the nanoscale characterization of emerging energy materials, which has not been possible with far-field optical techniques. The discussed methods utilize the AFM tip as a nanoscopic tool to extract spatially resolved electronic or molecular vibrational resonance spectra of a sample illuminated by a visible or infrared (IR) light source. The absorption of light by electrons or individual functional groups within molecules leads to changes in the sample’s thermal response, optical scattering, and atomic force interactions, all of which can be readily probed by an AFM tip. For example, photothermal induced resonance (PTIR) spectroscopy methods measure a sample’s local thermal expansion or temperature rise. Therefore, they use the AFM tip as a thermal detector to directly relate absorbed IR light to the thermal response of a sample. Optical scattering methods based on scanning near-field optical microscopy (SNOM) correlate the spectrum of scattered near-field light with molecular vibrational modes. More recently, photo-induced force microscopy (PiFM) has been developed to measure the change of the optical force gradient due to the light absorption by molecular vibrational resonances using AFM’s superb sensitivity in detecting tip-sample force interactions. Such recent efforts successfully breech the diffraction limit of light to provide nanoscale spatial resolution of vibrational spectroscopy, which will become a critical technique for characterizing novel energy materials.

关键词: vibrational spectroscopy     atomic force microscopy     photo-thermal induced resonance     scanning near-field optical microscopy     tip-enhanced Raman spectroscopy     photo-induced force microscopy     molecular resonances     surface phonon polaritons     energy materials    

Polymorphism and crystal transformation of penicillin sulfoxide

Dingding JING, Yongli WANG, Zhijian CHEN, Lina ZHOU, Jingkang WANG

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 442-447 doi: 10.1007/s11705-011-1140-x

摘要: Penicillin sulfoxide is the intermediate for the synthesis of 7-amino-3-desacetoxycephalosporanic acid which is one of the most important nucleuses of cephalosporin antibiotic. In this contribution, two crystal structures of penicillin sulfoxide (forms I and II) were determined by X-ray diffraction, and their thermotropic properties were investigated by differential scanning calorimetry (DSC). Furthermore, the transformation of form II to form I was studied quantitatively by Raman spectroscopy, and its rates at different temperatures were determined. The results indicate that penicillin sulfoxide is more stable as form I, and the temperature plays an important role in the crystal transformation.

关键词: penicillin sulfoxide     crystallization     polymorphism     crystal transformation     Raman spectroscopy    

Plasma-enabled healing of graphene nano-platelets layer

Xiuqi Fang, Carles Corbella, Denis B. Zolotukhin, Michael Keidar

《化学科学与工程前沿(英文)》 2019年 第13卷 第2期   页码 350-359 doi: 10.1007/s11705-018-1787-7

摘要: Graphene platelet networks (GPNs) were deposited onto silicon substrates by means of anodic arc discharge ignited between two graphite electrodes. Substrate temperature and pressure of helium atmosphere were optimized for the production of the carbon nanomaterials. The samples were modified or destroyed with different methods to mimic typical environments responsible of severe surface degradation. The emulated conditions were performed by four surface treatments, namely thermal oxidation, substrate overheating, exposition to glow discharge, and metal coating due to arc plasma. In the next step, the samples were regenerated on the same substrates with identical deposition technique. Damaging and re-growth of GPN samples were systematically characterized by scanning electron microscopy and Raman spectroscopy. The full regeneration of the structural and morphological properties of the samples has proven that this healing method by arc plasma is adequate for restoring the functionality of 2D nanostructures exposed to harsh environments.

关键词: graphene platelet networks     anodic arc discharge     plasma healing     scanning electron microscopy     Raman spectroscopy    

超短脉冲激光制造及表面加工微米器件 Review

于泳超, 白石, 王树同, 胡安明

《工程(英文)》 2018年 第4卷 第6期   页码 779-786 doi: 10.1016/j.eng.2018.10.004

摘要:

超短脉冲激光在材料加工方面具有独特的优势。其对焦点之外区域的热影响效应非常有限,使超短脉冲激光可被应用于微米甚至纳米尺寸的精密加工。另外,非线性多光子效应使超短脉冲激光可以加工多种透明材料,包括玻璃以及透明高分子材料。基于这些特点,我们利用激光直写技术在高分子衬底上成功制造出了具有三维(3D)结构的高性能微型超级电容器(MSC),在0.1 mA·cm–2的电流密度下表现出42.6 mF·cm–2的峰值比电容。同时,也制造出了可用于探测多种“味道”的柔性传感器阵列。对传感器电极表面进行了不同的处理,如镀金、沉降氧化石墨烯(rGO)以及沉积聚苯胺(PANI)。通过对采集的数据进行主成分分析(PCA),这一传感器阵列可以成功地检测出样品内的不同物质。另外,在3D 结构玻璃微流体通道内由全飞秒激光加工出了具有2D周期性结构的纳米金属表面,可用于实时表面增强拉曼散射(SERS)的检测。全飞秒激光加工过程包括激光烧蚀、激光还原和激光诱导表面纳米工程。这些工作证明了超短脉冲激光在表面精密加工中的巨大潜力。

关键词: 超短脉冲激光加工     微米器件     超级电容器     电子舌     表面增强拉曼光谱    

V-shaped substrate for surface and volume enhanced Raman spectroscopic analysis of microplastics

《环境科学与工程前沿(英文)》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1578-8

摘要:

● V-shaped substrate was obtained for SERS analysis of microplastics (diameter ≈ 1 μm).

关键词: SERS     V-shaped     AAO     Microplastic     Atmospheric aerosol    

Flame-retardant properties of

Kumar Sai SMARAN, Rajashekar BADAM, Raman VEDARAJAN, Noriyoshi MATSUMI

《能源前沿(英文)》 2019年 第13卷 第1期   页码 163-171 doi: 10.1007/s11708-018-0554-2

摘要: This paper focuses on the superiority of organic-inorganic hybrid ion-gel electrolytes for lithium-ion batteries (LiBs) over commercial electrolytes, such as 1 M LiPF in 1:1 ethylene carbonate (EC): dimethyl carbonate (DMC) {1 M LiPF -EC: DMC}, in terms of their flame susceptibility. These ion-gel electrolytes possess ionic liquid monomers, which are confined within the borosilicate or silicate matrices that are ideal for non-flammability. Naked flame tests confirm that the organic-inorganic hybrid electrolytes are less susceptible to flames, and these electrolytes do not suffer from a major loss in terms of weight. In addition, the hybrids are self-extinguishable. Therefore, these hybrids are only oxidized when subjected to a flame unlike other commercial electrolytes used in lithium-ion batteries. Supplementary analyses using differential scanning calorimetric studies reveal that the hybrids are glassy until the temperature reaches more than 100°C. The current results are consistent with previously published data on the organic-inorganic hybrids.

关键词: inorganic polymeric borosilicate network     organic-inorganic hybrids     self-extinguishability     nonflammability     lithium batteries     flame-retardants    

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

《能源前沿(英文)》 2016年 第10卷 第4期   页码 473-478 doi: 10.1007/s11708-016-0420-z

摘要: A dual input LED lighting scheme with constant illumination is proposed in this paper. The scheme employs a photovoltaic array as the first input and a battery as the second one. A microcontroller is programmed to operate a changeover switch as well as a DC-DC converter for uninterrupted and constant illumination in work place. The scheme is suitable for conference halls, laboratories, clean rooms, marriage halls, theaters, etc. The complete modeling, design and experimentation of the proposed scheme are explained and the economic viability of the scheme is justified.

关键词: photovoltaic     LED light     dual input     P&O algorithm    

Factors influencing near infrared spectroscopy analysis of agro-products: a review

Xiao XU, Lijuan XIE, Yibin YING

《农业科学与工程前沿(英文)》 2019年 第6卷 第2期   页码 105-115 doi: 10.15302/J-FASE-2019255

摘要:

The near infrared (NIR) spectroscopy technique has wide applications in agriculture with the advantages of being nondestructive, sensitive, safe and rapid. However, there are still more than 40 error sources influencing the robustness and accuracy of its calibration and operation. Environmental, sample and instrument factors that influence the analysis are discussed in this review, including temperature, humidity and other factors that introduce uncertainty. Error sources from livestock products, fruit and vegetables, which are the most common objects in the field of NIR analysis, are also emphasized in the second part. In addition, studies utilizing different instruments, spectral pretreatments, variable selection methods, wavelength ranges, detection modes and calibration methods are tabulated to illustrate the complications they introduce and how they influence NIR analysis. It is suggested that large scale of data with abundant varieties can be used to build a more robust calibration model, in order to improve the robustness and accuracy of the NIR analytical model, and overcome problems caused by confining analysis to too many uniform samples.

关键词: agro-product     error source     influence factor     near infrared spectroscopy    

Terahertz time-domain spectroscopy of high-pressure flames

Jason BASSI, Mark STRINGER, Bob MILES, Yang ZHANG

《能源前沿(英文)》 2009年 第3卷 第2期   页码 123-133 doi: 10.1007/s11708-009-0033-x

摘要: Laser spectroscopy in the visible and near infrared is widely used as a diagnostic tool for combustion devices, but this approach is difficult at high pressures within a sooty flame itself. High soot concentrations render flames opaque to visible light, but they remain transparent to far-infrared or terahertz (THz) radiation. The first far-infrared absorption spectra, to the best of our knowledge, of sooty, non-premixed, ethylene high-pressure flames covering the region of 0.2-2.5 THz is presented. A specially designed high-pressure burner which is optically accessible to THz radiation has been built allowing flame transmission measurements up to pressures of 1.6 MPa. Calculations of the theoretical combustion species absorption spectra in the 0.2-3 THz range have shown that almost all the observable features arise from H O. A few OH (1.84 and 2.51 THz), CH (2.58 THz), and NH (1.77 and 2.95 THz) absorption lines are also observable in principle. A large number of H O absorption lines are observed in the ground vibrational in a laminar non-premixed, sooty flame (ethylene) at pressures up to 1.6 MPa.

关键词: terahertz time-domain spectroscopy     high-pressure flames     H2O absorption lines    

Modeling of oil near-infrared spectroscopy based on similarity and transfer learning algorithm

Yifei Wang, Kai Wang, Zhao Zhou, Wenli Du

《化学科学与工程前沿(英文)》 2019年 第13卷 第3期   页码 599-607 doi: 10.1007/s11705-019-1807-2

摘要: Near-infrared spectroscopy mainly reflects the frequency-doubled and total-frequency absorption information of hydrogen-containing groups (O‒H, C‒H, N‒H, S‒H) in organic molecules for near-infrared lights with different wavelengths, so it is applicable to testing of most raw materials and products in the field of petrochemicals. However, the modeling process needs to collect a large number of laboratory analysis data. There are many oil sources in China, and oil properties change frequently. Modeling of each raw material is not only unfeasible but also will affect its engineering application efficiency. In order to achieve rapid modeling of near-infrared spectroscopy and based on historical data of different crude oils under different detection conditions, this paper discusses about the feasibility of the application of transfer learning algorithm and makes it possible that transfer learning can assist in rapid modeling using certain historical data under similar distributions under a small quantity of new data. In consideration of the requirement of transfer learning for certain similarity of different datasets, a transfer learning method based on local similarity feature selection is proposed. The simulation verification of spectral data of 13 crude oils measured by three different probe detection methods is performed. The effectiveness and application scope of the transfer modeling method under different similarity conditions are analyzed.

关键词: near-infrared spectroscopy     transfer learning     similarity     modeling    

Ternary phase behavior of water microemulsified diesel-palm biodiesel

Nurul Atiqah Izzati MD ISHAK,Ismail Ab RAMAN,Mohd Ambar YARMO,Wan Mohd Faizal WAN MAHMOOD

《能源前沿(英文)》 2015年 第9卷 第2期   页码 162-169 doi: 10.1007/s11708-015-0355-9

摘要: This paper aims to develop a new microemulsions system comprising diesel and palm oil methyl ester (PME) that have the potential to be used as alternative fuels for diesel engines. The water-in-diesel-biodiesel microemulsions were prepared by applying PME mixed with diesel, non-ionic surfactants, co-surfactants and water to make the water-in-oil (W/O) microemulsion system. This microemulsified fuel was achieved through low-energy microemulsification by using the constant composition method. The diesel used was mixed with four different concentrations of PME, i.e., 10% (w/w) (B10), 20% (w/w) (B20), 30% (w/w) (B30) and neat diesel (B0). The amount of water was fixed at 20% (w/w). The phase behavior of the water/mixed non-ionic surfactant/diesel-PME system were studied by constructing pseudoternary phase diagrams with the goal of formulating optimized systems. The results showed that the microemulsions were formed and stabilized with a mixture of non-ionic surfactants at a weight ratio of 80:20 at 20% (w/w), and with mixed co-surfactants at a weight ratio of 25:75, 20:80 and 10:90 for B0, B10, B20 and B30 respectively. The particle size, kinematic viscosity at 40°C, refractive index, density, heating value, cloud point, pour point and flash point of the selected water-in-diesel microemulsion were 19.40 nm (polydispersity of 0.12), 2.86 mm /s, 1.435, 0.8913 g/mL, 31.87 MJ/kg, 7.15°C, 10.5°C and 46.5°C respectively. The corresponding values of the water-in-diesel-PME selected were 20.72 nm to 23.74 nm, 13.02 mm /s to 13.29 mm /s, 1.442, 0.8939 g/mL to 0.8990 g/mL, 31.45 MJ/kg to 27.34 MJ/kg, 7.2°C to 6.8°C, 8.5°C to 1.5°C and 47.5°C to 52.0°C. These preliminary findings were further studied as potential fuels for diesel engines.

关键词: palm methyl ester     palm oil biodiesel     microemulsion     water microemulsified fuels    

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0705-3

摘要: As a nondestructive testing technique, terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings (TBCs). However, the invisibility of ceramic/thermally grown oxide (TGO) reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10 μm in TBCs. To detect and monitor TGO in the emergence stage, a time of flight (TOF) improved TGO thickness measurement method is proposed. A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave. The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation. Thus, the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times. The averaged error of 1.61 μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method, making it attractive for condition monitoring and life prediction of TBCs.

关键词: thermal barrier coatings     thermally grown oxide     terahertz spectroscopy     time of flight    

Large deflection behavior effect in reinforced concrete columns exposed to extreme dynamic loads

MUTALIB, Chunwei ZHANG, Javad MEHRMASHHADI, Sudharshan Naidu RAMAN, Roozbeh ALIPOUR, Tohid MOMENI, Mohamed

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 532-553 doi: 10.1007/s11709-020-0604-9

摘要: Reinforced concretes (RC) have been widely used in constructions. In construction, one of the critical elements carrying a high percentage of the weight is columns which were not used to design to absorb large dynamic load like surface bursts. This study focuses on investigating blast load parameters to design of RC columns to withstand blast detonation. The numerical model is based on finite element analysis using LS-DYNA. Numerical results are validated against blast field tests available in the literature. Couples of simulations are performed with changing blast parameters to study effects of various scaled distances on the nonlinear behavior of RC columns. According to simulation results, the scaled distance has a substantial influence on the blast response of RC columns. With lower scaled distance, higher peak pressure and larger pressure impulse are applied on the RC column. Eventually, keeping the scaled distance unchanged, increasing the charge weight or shorter standoff distance cause more damage to the RC column. Intensive studies are carried out to investigate the effects of scaled distance and charge weight on the damage degree and residual axial load carrying capacity of RC columns with various column width, longitudinal reinforcement ratio and concrete strength. Results of this research will be used to assessment the effect of an explosion on the dynamic behavior of RC columns.

关键词: RC column     scaled distance     blast load     LS-DYNA    

标题 作者 时间 类型 操作

Cystine-assisted accumulation of gold nanoparticles on ZnO to construct a sensitive surface-enhanced Ramanspectroscopy substrate

期刊论文

Chemical mapping of cement pastes by using confocal Raman spectroscopy

Fengjuan LIU,Zhihui SUN

期刊论文

Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

期刊论文

Polymorphism and crystal transformation of penicillin sulfoxide

Dingding JING, Yongli WANG, Zhijian CHEN, Lina ZHOU, Jingkang WANG

期刊论文

Plasma-enabled healing of graphene nano-platelets layer

Xiuqi Fang, Carles Corbella, Denis B. Zolotukhin, Michael Keidar

期刊论文

超短脉冲激光制造及表面加工微米器件

于泳超, 白石, 王树同, 胡安明

期刊论文

V-shaped substrate for surface and volume enhanced Raman spectroscopic analysis of microplastics

期刊论文

Flame-retardant properties of

Kumar Sai SMARAN, Rajashekar BADAM, Raman VEDARAJAN, Noriyoshi MATSUMI

期刊论文

Solar photovoltaic fed dual input LED lighting system with constant illumination control

Kinattingal SUNDARESWARAN,Kevin Ark KUMAR,Payyalore Raman VENKATESWARAN,Sankaran PALANI

期刊论文

Factors influencing near infrared spectroscopy analysis of agro-products: a review

Xiao XU, Lijuan XIE, Yibin YING

期刊论文

Terahertz time-domain spectroscopy of high-pressure flames

Jason BASSI, Mark STRINGER, Bob MILES, Yang ZHANG

期刊论文

Modeling of oil near-infrared spectroscopy based on similarity and transfer learning algorithm

Yifei Wang, Kai Wang, Zhao Zhou, Wenli Du

期刊论文

Ternary phase behavior of water microemulsified diesel-palm biodiesel

Nurul Atiqah Izzati MD ISHAK,Ismail Ab RAMAN,Mohd Ambar YARMO,Wan Mohd Faizal WAN MAHMOOD

期刊论文

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

期刊论文

Large deflection behavior effect in reinforced concrete columns exposed to extreme dynamic loads

MUTALIB, Chunwei ZHANG, Javad MEHRMASHHADI, Sudharshan Naidu RAMAN, Roozbeh ALIPOUR, Tohid MOMENI, Mohamed

期刊论文