Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)最新文献_第3页

Vibrational spectroscopic applications for detecting of consolidated harakeke fibres in conservation 振动光谱在检测固结harakeke纤维守恒中的应用

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.59

P. S. G. Arachchige, I. Paasi, Dunne Henry, J. L. Brownyn, A. Catherine, J. F. Sara, C. Keith

{"title":"Vibrational spectroscopic applications for detecting of consolidated harakeke fibres in conservation","authors":"P. S. G. Arachchige, I. Paasi, Dunne Henry, J. L. Brownyn, A. Catherine, J. F. Sara, C. Keith","doi":"10.32655/asc_8-10_dec2020.59","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.59","url":null,"abstract":"Traditional Māori textiles are mostly composed of harakeke fibres (Phormium tenax, New Zealand flax) and coloured by various natural dyes. Fibres are dyed black (paru) with iron tannate compounds [1]. These textiles are liable to degradation which is believed to occur via acid catalysed hydrolysis and iron catalysed oxidation [1, 2]. To mitigate this degradation, these textiles are treated with different consolidants. There is however a poor understanding of the mode of action of consolidants at a molecular level. In this study, paru dyed and non-dyed harakeke fibre samples treated with the common consolidants; sodium alginate, zinc alginate, Paraloid B-72TM, TriFunoriTM, and MethocelA4CTM were assessed by bulk Raman and infrared (IR) spectroscopic techniques. These consolidated fibers were artificially aged using light ageing to evaluate for potential protective effects from the consolidants [3]. Also, non-dyed, consolidated fibres were studied by Raman microscopic analysis to detect the consolidant distribution within the sample. These data were analysed using; band integrals analysis, principal component analysis, and true component analysis, was applied to understand subtle variances in the samples of bulk and microscopic analysis (Fig. 1).","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129403065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

2D electronic spectroscopy study of TIPS - pentacene TIPS -并五苯的二维电子能谱研究

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.45

Le Duc Viet, Leng Xuan, Do Thanh Nhut, Tan Howe Siang, Perrelle Jessica M. de la, W. Tak

{"title":"2D electronic spectroscopy study of TIPS - pentacene","authors":"Le Duc Viet, Leng Xuan, Do Thanh Nhut, Tan Howe Siang, Perrelle Jessica M. de la, W. Tak","doi":"10.32655/asc_8-10_dec2020.45","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.45","url":null,"abstract":"The molecule TIPS – Pentacene has gained a lot of attraction recently due to its ability to exhibit the singlet fission phenomenon, which has the potential of improving power conversion efficiency significantly in photovoltaic devices 1 . Therefore, investigating into the photophysical properties of this molecule can assist researchers in better understanding the singlet fission phenomenon. 2D Electronic spectroscopy of TIPS – Pentacene in solution shown a strong beating at 265cm -1 in both the amplitude and the central line slope 2 , which corresponds to a breathing mode of the molecule. The 2D spectra , , can be understood using the theory of a two level system coupled to a series of harmonic oscillators 3 . The resultant lineshape function 𝑔(cid:4666)𝑡(cid:4667) of the system can be partitioned into two functions: 𝑔 (cid:3029) (cid:4666)𝑡(cid:4667) (environment) and 𝑔 (vibrational mode). A full expansion of the lineshape function 𝑔(cid:4666)𝑡(cid:4667) in the third order nonlinear optical response functions can be used to simulate the experimental 2D spectra, including the 2D Fourier map at 265 cm (cid:2879)(cid:2869) (Fig.1c) and the Centre Line Slope analysis (Fig.1d).","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123045872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling excitonic energy transfers in Bryopsis corticulans using 2D electronic spectroscopy 利用二维电子能谱模拟苔藓微粒中的激子能量转移

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.46

H. L. Nguyen, T. N. Do, P. Akhtar, T. I. Jansen, J. Knoester, P. Lambrev, H. Tan

{"title":"Modelling excitonic energy transfers in Bryopsis corticulans using 2D electronic spectroscopy","authors":"H. L. Nguyen, T. N. Do, P. Akhtar, T. I. Jansen, J. Knoester, P. Lambrev, H. Tan","doi":"10.32655/asc_8-10_dec2020.46","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.46","url":null,"abstract":"We apply a phenomenological fitting method to the two-dimensional electronic spectra of the light-harvesting complex II (LHCII) from Bryopsis corticulans ( B. corticulans ) at 77 K to extract information about the excitonic states and energy transfer processes. B. corticulans is a marine green alga whose photosynthesis adapts to the underwater environment; thus, its properties are expected to deviate from the widely studied plant LHCII to some extent. The fitting method results in well converged parameters, including eight excitonic energy levels with their respective transition dipole moments, spectral widths, energy transfer rates and coupling properties. The 2D spectra simulated from the fitted parameters concur very well with the experimental data, proving the robustness of the fitting method. An excitonic energy transfer scheme can be constructed from the fitting parameters, which is described for the first-time for B. corticulans LHCII. The strength of our phenomenological fitting method in obtaining excitonic energy levels and energy transfer network is put to good test in systems such as B. corticulans LHCII where prior knowledge and exact assignment and spatial locations of pigments are lacking. We hope future full structural determination of B. corticulans LHCII can validate our predictions.","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116938519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Data fusion strategy for quantitative analysis of n-3 fatty acids in commercial krill oil 商业磷虾油n-3脂肪酸定量分析的数据融合策略

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.58

F. Ahmmed, I. D. Fuller, D. Killeen, S. Fraser‐Miller, K. Gordon

{"title":"Data fusion strategy for quantitative analysis of n-3 fatty acids in commercial krill oil","authors":"F. Ahmmed, I. D. Fuller, D. Killeen, S. Fraser‐Miller, K. Gordon","doi":"10.32655/asc_8-10_dec2020.58","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.58","url":null,"abstract":"Raman and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy were used to analyse seven krill oil capsules and twenty-five calibration samples to quantitate astaxanthin, EPA plus DHA and other important fatty acids. Spectroscopic data was calibrated against FAME profiles (measured by GC-MS) and astaxanthin concentrations (measured by UV-VIS). Raman spectra was found to be suitable to quantify astaxanthin, EPA, DHA and EPA + DHA, with reasonable root mean square error of prediction (RMSEP) for test set validation: 40 μg g -1 , 2.5%, 2.2% and 4.5% respectively. EPA, DHA and EPA+DHA concentrations in krill oil could also be quantitatively modelled using IR spectra, but astaxanthin was not acceptably modelled using this approach. Fusion of the spectroscopic methods were carried out at low (concatenation), medium (PCA scores for feature extraction) and high (central limit theorem) levels. Models generated from low-level and mid-level data fusion had corresponding errors (RMSEP) of 3.8%, 4.8%, 1.1% and 1.9% for MUFA, PUFA, EPA and EPA + DHA, respectively, which were better than the individual techniques [1].","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124247078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Role of vibrational spectroscopy in characterization of drug-ligand interaction 振动光谱在药物-配体相互作用表征中的作用

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.71

Devi Th. Gomti

引用次数: 0

Ultrafast vibrational dynamics induced by the photodetachment of aqueous phenylalanine anion 水溶液苯丙氨酸阴离子光脱离诱导的超快振动动力学

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.56

Yang Ningchen, Siow Jing Xuan, Loh Zhi-Heng

{"title":"Ultrafast vibrational dynamics induced by the photodetachment of aqueous phenylalanine anion","authors":"Yang Ningchen, Siow Jing Xuan, Loh Zhi-Heng","doi":"10.32655/asc_8-10_dec2020.56","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.56","url":null,"abstract":"The interaction of biomolecules with ionising radiation in an aqueous environment is a fundamental process that is not well researched [1]. Understanding the photoionization or photodetachment of amino acids can help us better understand and solve problems related to radical chemistry and radioactive processes in natural systems [2]. In this study, we use femtosecond optical pump-probe spectroscopy to explore the photodetachment of the phenylalanine anion, an aromatic amino acid. Photodetachment of phenylalanine anion in aqueous alkaline solution triggers vibrational wave packet dynamics as well as a rapid, picosecond decay of the phenylalanine radical population (Fig. 1. (a)). Both existing literature and our ab initio calculations suggest that the photodissociation of phenylalanine radical into carbon dioxide and benzeneethanamine radical is a dominant process. While we have yet to uncover experimental evidence of this phenomenon on the sub-picosecond to picosecond timescale, we identified several key vibrational modes belonging to phenylalanine radical by comparing experimental and ab initio results (Fig 1. (b)). Overall, studying the vibrational wave packet dynamics of phenylalanine induced by photodetachment can provide a more nuanced understanding of the effects of ionising radiation on aromatic amino acids.","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122049503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Charge transfer and charge separation dynamics in efficient non-fullerene solar cells 高效非富勒烯太阳能电池的电荷转移和电荷分离动力学

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.15

Ma Chao, C. S. C. Christopher, C. Y. C. Philip, Yan He, Wong Kam Sing

{"title":"Charge transfer and charge separation dynamics in efficient non-fullerene solar cells","authors":"Ma Chao, C. S. C. Christopher, C. Y. C. Philip, Yan He, Wong Kam Sing","doi":"10.32655/asc_8-10_dec2020.15","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.15","url":null,"abstract":"Recently, Non-fullerene organic solar cells (OSCs) has been making rapid progress and reaching record breaking efficiency [1]. In the conventional idea for the fullerene based OSCs, one need a large donor-acceptor (D/A) offsets to cause rapid (i.e., <1ps) and effective charge separation from exciton at the D/A heterojunction [2]. However, recent work showed that non-fullerene OSC with small D/A offset can also achieved very high power conversion efficiency (PCE) [1,3-4]. The explanation for this is that charge separation occurs over hundreds of ps from thermalized charge transfer exciton (CTEs) at the D/A heterojunction for the non-fullerene system [5], thus charge separation in efficient non-fullerene OSC with small D/A offset is an endothermic process. Here we will present our recent transient absorption (TA) spectroscopy studies to further elucidate the temperature dependence of charge transfer and charge separation dynamics in a number of nonfullerene OSC model systems with negligible D/A LUMO offset but variable HOMO offsets. We selectively create acceptor excitons and showed that acceptor excitons dissociate into CTEs at a similar rate (~100ps) as donor excitons despite the significantly large driving force provided by the HOMO offset. In contrast, by tracing the electro-absorption signal, it was demonstrated the generation of free charges after hole transfer required additional thermal excitation. Our result show the charge separation is indeed an endothermic behavior in non-fullerene OSCs, but charge transfer is not. Our result give a deeper understanding of the working mechanism of non-fullerene OSCs, which will have important fundamental implications on the development of OSCs.","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132262439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanism and application of oxygen-independent photocleavage of blebbistatin as a blue or near-infrared light-gated hydroxyl radical photocage blebbistatin作为蓝光或近红外光门控羟基光笼的不依赖氧的光裂解机理及应用

Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020) Pub Date : 2020-12-01 DOI: 10.32655/asc_8-10_dec2020.6

Li Ming-de, Wong Nai-Kei, Huang Guanheng, Chen Xuebo, Yang Dan, Phillips David Lee

{"title":"Mechanism and application of oxygen-independent photocleavage of blebbistatin as a blue or near-infrared light-gated hydroxyl radical photocage","authors":"Li Ming-de, Wong Nai-Kei, Huang Guanheng, Chen Xuebo, Yang Dan, Phillips David Lee","doi":"10.32655/asc_8-10_dec2020.6","DOIUrl":"https://doi.org/10.32655/asc_8-10_dec2020.6","url":null,"abstract":"Development of versatile, chemically tunable photocages for photoactivated chemotherapy (PACT) represents an excellent opportunity to address the technical drawbacks of conventional photodynamic therapy (PDT) whose oxygen-dependent nature renders it inadequate in certain therapy contexts such as hypoxic tumors. As an alternative to PDT, oxygen free mechanisms to generate cytotoxic reactive oxygen species (ROS) by visible light cleavable photocages are in demand. Here, we report the detailed mechanisms by which the small molecule blebbistatin acts as a one-photon blue light-gated or two-photon nearinfrared light-gated photocage to directly release a hydroxyl radical (•OH) in the absence of oxygen. By using femtosecond transient absorption spectroscopy, resonance Raman and chemoselective ROS fluorescent probes, we analyze the dynamics and fate of blebbistatin during photolysis under blue light. Water-dependent photochemistry reveals a critical process of water-assisted protonation and excited state intramolecular proton transfer (ESIPT) that drives the formation of short-lived intermediates, which surprisingly culminates in the release of •OH but not superoxide or singlet oxygen from blebbistatin. CASPT2//CASSCF calculations confirm that hydrogen bonding between water and blebbistatin underpins this process. We further determine that blue light enables blebbistatin to induce mitochondria-dependent apoptosis, an attribute conducive to PACT development. Our work demonstrates blebbistatin as a controllable photocage for •OH generation and provides insight into the potential development of novel PACT agents.[1,2]","PeriodicalId":133438,"journal":{"name":"Proc. Of the 7th Asian Spectroscopy Conference (ASC 2020)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125056286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0