Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of t...Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.展开更多
The microstructure and texture of C/C composites with a resin-derived carbon, a rough laminar （RL） pyrocarbon and a smooth laminar pyrocarbon, before and after braking tests, were investigated by Raman spectroscopy....The microstructure and texture of C/C composites with a resin-derived carbon, a rough laminar （RL） pyrocarbon and a smooth laminar pyrocarbon, before and after braking tests, were investigated by Raman spectroscopy. The full width at half maximum （FWHM） of the D-band indicates the amount of defects in the in-plane lattice, while the G-to-D band intensity （peak area） ratios （lC/ID） is used to evaluate the degree of graphitization. The results show that the FWHM of D-band of sample with RL pyrocarbon changes greatly from 36 cm-1 to 168 cm 1 after braking tests, which indicates that a large number of lattice defects are produced on its wear surface. However, the graphitization degree of resin-derived carbon sample rises significantly, because the IC/1D increases from 0.427 to 0.928. Braking tests under normal loading conditions, involving high temperature and high pressure, produce a lot of lattice defects on the wear surface, and induce the graphitization of the surface. Sample with RL pyrocarbon having a low hardness is easy to deform, and has the most lattice defects on the wear surface after braking. While raw materials with resin-derived carbon have the lowest graphitization degree which rises greatly during braking.展开更多
Illegal production of alcoholic beverages is a common problem in most countries.The consumption of these counterfeit alcoholic products in Turkey has increasingly been one of the major health concerns.In this study,a ...Illegal production of alcoholic beverages is a common problem in most countries.The consumption of these counterfeit alcoholic products in Turkey has increasingly been one of the major health concerns.In this study,a comparison between GC-MS and Raman spectroscopy techniques was made to determine the amount of methanol in BogmaRaki which is a counterfeit alcoholic beverage produced and consumed in Hatay region.Different ratios of methanol/ethanol concentrations were prepared to obtain a calibration curve.This curve was used to measure the amount of methanol in the actual product samples using both GC-MS and Raman spectroscopy techniques.Results obtained from both techniques were compared using Paired sample t-tests.The Limit of Detection and the Limit of Quantification values were determined as 0.03(%v/v) and 0.11(%v/v),respectively.Both techniques demonstrated a similar sensitivity in the determination of methanol concentration in these counterfeit products(p>0.05).Raman Spectroscopy,however,has an advantage of being easy to use,inexpensive,rapid and non-destructive analytical technique with little or no sample preparation.展开更多
Graphene, the thinnest and hardest nano-material in the world, is non-toxic, sustainable and with minimal environmental footprint. As one of the most important carbon materials, it is composed of a monolayer of carbon...Graphene, the thinnest and hardest nano-material in the world, is non-toxic, sustainable and with minimal environmental footprint. As one of the most important carbon materials, it is composed of a monolayer of carbon atoms with a honeycomb structure. Nowadays, scientists have tried to use it in the biomedicine subject because of its superior physical and chemical properties and excellent biocompatibility.展开更多
Automated core scanning technologies for mineralogical characterisation of diamond core, drill chips pulps is now an established technique, particularly in the Australian iron ore industry, for mineral analysis in exp...Automated core scanning technologies for mineralogical characterisation of diamond core, drill chips pulps is now an established technique, particularly in the Australian iron ore industry, for mineral analysis in exploration and mining. Application of reflectance spectroscopy over the 400–2500 nm, visible to near-infrared wavelength range, has been used to characterise the iron ore oxide mineralogy of bedded iron deposit (BID) derived iron ores in India (Thangavelu et al., 2011) and Brazil (da Costa et al., 2009), and used to define the ore and gangue (e.g., clay) mineralogy in ironstone or channel iron deposits (CID) in the Pilbara region of Western Australia (e.g., Haest et al., 2012).展开更多
近年来,一些不法商贩向抗疲劳、壮阳和调节免疫力等类别保健食品中非法添加磷酸二酯酶5型抑制剂(phosphodiesterase type 5 inhibitors,PDE5is),严重威胁消费者健康,为提高市场监管和筛查效率,亟需建立相关现场快速检测方法。该研究基...近年来,一些不法商贩向抗疲劳、壮阳和调节免疫力等类别保健食品中非法添加磷酸二酯酶5型抑制剂(phosphodiesterase type 5 inhibitors,PDE5is),严重威胁消费者健康,为提高市场监管和筛查效率,亟需建立相关现场快速检测方法。该研究基于表面增强拉曼光谱技术,以自制金溶胶为增强试剂,盐酸氯化钠溶液为匹配剂,使用乙腈和硫酸溶液进行样品前处理,建立了液体保健食品中90种非法添加PDE5is的筛查方法。该方法灵敏度高、准确性好,检出限为1~10μg/mL,为快速检测保健食品中非法添加药物提供了可靠的技术参考。展开更多
基金Project(10804101) supported by the National Natural Science Foundation of ChinaProject(2007CB815102) supported by the National Basic Research Program of ChinaProject(2007B08007) supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.
基金Project(2006CB600906) supported by the National Basic Research Program of China
文摘The microstructure and texture of C/C composites with a resin-derived carbon, a rough laminar （RL） pyrocarbon and a smooth laminar pyrocarbon, before and after braking tests, were investigated by Raman spectroscopy. The full width at half maximum （FWHM） of the D-band indicates the amount of defects in the in-plane lattice, while the G-to-D band intensity （peak area） ratios （lC/ID） is used to evaluate the degree of graphitization. The results show that the FWHM of D-band of sample with RL pyrocarbon changes greatly from 36 cm-1 to 168 cm 1 after braking tests, which indicates that a large number of lattice defects are produced on its wear surface. However, the graphitization degree of resin-derived carbon sample rises significantly, because the IC/1D increases from 0.427 to 0.928. Braking tests under normal loading conditions, involving high temperature and high pressure, produce a lot of lattice defects on the wear surface, and induce the graphitization of the surface. Sample with RL pyrocarbon having a low hardness is easy to deform, and has the most lattice defects on the wear surface after braking. While raw materials with resin-derived carbon have the lowest graphitization degree which rises greatly during braking.
基金There isn’t fund project and this issue was presented as a poster at the 7th European Academy of Forensic Science Conference,Prague,2015
文摘Illegal production of alcoholic beverages is a common problem in most countries.The consumption of these counterfeit alcoholic products in Turkey has increasingly been one of the major health concerns.In this study,a comparison between GC-MS and Raman spectroscopy techniques was made to determine the amount of methanol in BogmaRaki which is a counterfeit alcoholic beverage produced and consumed in Hatay region.Different ratios of methanol/ethanol concentrations were prepared to obtain a calibration curve.This curve was used to measure the amount of methanol in the actual product samples using both GC-MS and Raman spectroscopy techniques.Results obtained from both techniques were compared using Paired sample t-tests.The Limit of Detection and the Limit of Quantification values were determined as 0.03(%v/v) and 0.11(%v/v),respectively.Both techniques demonstrated a similar sensitivity in the determination of methanol concentration in these counterfeit products(p>0.05).Raman Spectroscopy,however,has an advantage of being easy to use,inexpensive,rapid and non-destructive analytical technique with little or no sample preparation.
文摘Graphene, the thinnest and hardest nano-material in the world, is non-toxic, sustainable and with minimal environmental footprint. As one of the most important carbon materials, it is composed of a monolayer of carbon atoms with a honeycomb structure. Nowadays, scientists have tried to use it in the biomedicine subject because of its superior physical and chemical properties and excellent biocompatibility.
文摘Automated core scanning technologies for mineralogical characterisation of diamond core, drill chips pulps is now an established technique, particularly in the Australian iron ore industry, for mineral analysis in exploration and mining. Application of reflectance spectroscopy over the 400–2500 nm, visible to near-infrared wavelength range, has been used to characterise the iron ore oxide mineralogy of bedded iron deposit (BID) derived iron ores in India (Thangavelu et al., 2011) and Brazil (da Costa et al., 2009), and used to define the ore and gangue (e.g., clay) mineralogy in ironstone or channel iron deposits (CID) in the Pilbara region of Western Australia (e.g., Haest et al., 2012).
文摘近年来,一些不法商贩向抗疲劳、壮阳和调节免疫力等类别保健食品中非法添加磷酸二酯酶5型抑制剂(phosphodiesterase type 5 inhibitors,PDE5is),严重威胁消费者健康,为提高市场监管和筛查效率,亟需建立相关现场快速检测方法。该研究基于表面增强拉曼光谱技术,以自制金溶胶为增强试剂,盐酸氯化钠溶液为匹配剂,使用乙腈和硫酸溶液进行样品前处理,建立了液体保健食品中90种非法添加PDE5is的筛查方法。该方法灵敏度高、准确性好,检出限为1~10μg/mL,为快速检测保健食品中非法添加药物提供了可靠的技术参考。
