Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appro...Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appropriate sulfurization conditions were studied. For the rare earth sulfides with the same crystal structure, the sulfurization temperature showed increasing tendency with the decrease of rare earth element atomic radii. The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. The data showed that the optical band gaps of rare earth sulfides were irregular, and the values ranged from 1.65 to 3.75 eV.展开更多
The interactions of 4-aminosalicylic acid （4-ASA） and surfactants in aqueous solutions were investigated by using UV-Vis spectra and steady-state fluorescence spectroscopy.The results showed that the strongest peak ...The interactions of 4-aminosalicylic acid （4-ASA） and surfactants in aqueous solutions were investigated by using UV-Vis spectra and steady-state fluorescence spectroscopy.The results showed that the strongest peak at UV-vis spectra of 4-ASA aqueous solution in the presence of cationic surfactant and cetyltrimethyl ammonium bromide （CTAB） appeared at 206 nm and took a red shift from 206 nm to 221 nm with the increase of 4-ASA concentrations from 0.8×10-5 to 4.4×10-4 mol/L.Similarly,the strongest peak at UV-vis spectra of 4-ASA aqueous solution in the presence of nonionic surfactant and polyvinylpyrrolidone （PVP） appeared at 206 nm and took a red shift from 206 nm to 219 nm with the increase of 4-ASA concentrations from 0.8×10-5 to 4.4×10-4 mol/L.However,the similar phenomena did not appeared in the presence of anion surfactant,sodium dodecyl sulfate （SDS）,the UV-vis spectra of 4-ASA aqueous solution remained the same peak position and the peak value increased with the 4-ASA concentration increase.The results could be attributed to the electrostatic attraction between 4-ASA and CTAB or PVP,as well as the electrostatic repulsion between 4-ASA and SDS.Furthermore,the value of critical micelle concentration （CMC） of surfactants in the presence of 4-ASA was determined with Fluorescence method.The first and second CMC of CTAB was 1.2×10-4 M and 2.4×10-4 M,respectively.The first and second CMC of PVP was 1.2×10-4 M and 2.8×10-4 M.SDS realized the multiple micellizations to form multiple CMC.展开更多
Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors ha...Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors have begun to appear in the market. Therefore, it is an urgent need for new techniques to discriminate the genuine and counterfeit Moutai liquor. In this work, the conventional Ultraviolet-Visible (UV-Vis) spectroscopy and two-dimensional correlation UV-Vis spectroscopy are applied to obtain the UV-Vis characteristic of Moutai liquor and counterfeit one, respectively. The experimental results reveal that the conventional UV-Vis spectra of the genuine and counterfeit Moutai liquor are similar. However, the two-dimensional correlation UV-Vis spectra of them are different and this method would be applied to differentiate the counterfeit Moutai liquor from the genuine Moutai liquor. Compared with conventional methods, this novel method has the advantages of easy operation, simple instrumentation and direct recognition, which make it a potential tool in the fields of food safety.展开更多
Reactive bright blue rare earth dyestuffs were prepared by using reactive bright blue and lanthanum oxide,praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, dysprosium oxide, erbium...Reactive bright blue rare earth dyestuffs were prepared by using reactive bright blue and lanthanum oxide,praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, dysprosium oxide, erbium oxide, lutetium oxide, yttrium oxide respectively for dyeing silk cloth.The degree of dyeing of reactive bright blue praseodymium and the degree of fixation of reactive bright blue gadolinium are the biggest, and 22.9% and 7 %are increased with that of reactive bright blue respectively.The spectra of reactive bright blue rare earth and reactive bright blue were studied by UV-VIS.In 200.00 ～ 800.00 nm, reactive bright blue has four absorption peaks, reactive bright blue rare earth has three absorption peaks; in 420.00 ～ 760.00 nm, reactive bright blue has two absorption peaks at 661.50 nm and 625.50 nm, respectively, and λmax is 661.50 nm; reactive bright blue rare earth has one absorption peak at 620.50, 618.00, 622.00, 623.00, 622.50, 619.50, 619.00, 621.00, 624.00, 620.00 nm adding La3+ ,Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Dy3+, Er3+, Lu3+, Y3+respectively.展开更多
Being widely used as good ligands,xanthates and related compounds have been extensively investigated.However,reports on Pt（Ⅱ） xanthates have been sparse so far.Watt et al.reported the synthesis and characterization...Being widely used as good ligands,xanthates and related compounds have been extensively investigated.However,reports on Pt（Ⅱ） xanthates have been sparse so far.Watt et al.reported the synthesis and characterization of Pt（S;COR）;（R=Me,Et）,but did not provide any absorption spectra of these complexes.We prepared twelve platinum （Ⅱ） xanthate complexes and examined their absorption spectra in detail.展开更多
Reactive blue rare earth dyestuffs were prepared by using reactive blue and lanthanum oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, erbi...Reactive blue rare earth dyestuffs were prepared by using reactive blue and lanthanum oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, erbium oxide, lutetium oxide and yttrium oxide respectively for dyeing silk cloth. The degrees of dyeing of reactive blue gadolinium and fixation of reactive blue neodymium were the biggest respectively, were 84.83% and 97.96 respectively, were 24.13% and 8.36% were increased with that of reactive blue respectively. The spectra of reactive blue rare earths and reactive blue were studied by UV-VIS. In 200.00～800.00 nm, the λmax of reactive blue, reactive blue lanthanum, reactive blue praseodymium, reactive blue neodymium, reactive blue samarium, reactive blue europium, reactive blue gadolinium, reactive blue terbium, reactive blue dysprosium, reactive blue erbium, reactive blue lutetium and reactive blue yttrium are 599.00, 600.00, 602.00, 601.00, 600.00, 600.50, 600.50, 601.00, 600.00, 600.50, 599.50 and 600.50 nm respectively. Reactive blue lanthanum, reactive blue praseodymium, reactive blue neodymium, reactive blue samarium, reactive blue europium, reactive blue gadolinium, reactive blue terbium, reactive blue dysprosium, reactive blue erbium, reactive blue lutetium, reactive blue yttrium and reactive blue had almost same color.展开更多
A bis-2-iminopyrrole compound（1） and its difluoroboron complex（2） were synthesized and characterized. The crystal of 2 is in the monoclinic system, P2_1/n space group with a = 21.5113（15）, b = 6.3036（3）, c = 2...A bis-2-iminopyrrole compound（1） and its difluoroboron complex（2） were synthesized and characterized. The crystal of 2 is in the monoclinic system, P2_1/n space group with a = 21.5113（15）, b = 6.3036（3）, c = 21.5064（15） A, V = 2826.3（7） A^3, Z = 4, C_（26.5） H_（25） B_2 ClF_4 N_4 O, M_r = 548.57, D_c = 1.390 g/cm, F（000） = 1132 and μ（MoKα） = 1.787 mm^-1. The final R = 0.0647 and wR = 0.1817 for 10346 observed reflections with I 〉 2σ（I）, and R = 0.0889 and wR = 0.1993 for all data. The molecules of complex 2 self-assemble through C–H×××F hydrogen bonds and form tubular structures which are filled by CH_2 Cl_2 molecules stabilized by C–H×××π interaction. The UV-Vis spectra of complex 2 show great bathochromic shift compared to that of compound 1 due to the difluoroboron complexing. Complex 2 shows fluorescence emission both in solid state and in solution, whereas compound 1 only exhibits fluorescence emission in solid state.展开更多
Optimizing sewage collection is important for water pollution control and wastewater treatment plants quality and efficiency improvement.Currently,the urban drainage pipeline network is upgrading to improve its classi...Optimizing sewage collection is important for water pollution control and wastewater treatment plants quality and efficiency improvement.Currently,the urban drainage pipeline network is upgrading to improve its classification and collection ability.However,there is a lack of efficient online monitoring and identification technology.UV-visible absorption spectrum probe is considered as a potential monitoring method due to its small size,reagent-free and fast detection.Because the performance parameters of probe like optic resolution,dynamic interval and signal-to-noise ratio are weak and high turbidity of sewage raises the noise level,it is necessary to extract shape features from the turbidity disturbed drainage spectrum for classification purposes.In this study,drainage network samples were online collected and tested,and four types were labeled according to sample sites and environment situation.Derivative spectrum were adopted to amplify the shape features,while convolutional neural network algorithm was established to conduct nonlinear spectrum classification.Influence of input and network structure on classification accuracy was compared.Original spectrum,first-order derivative spectrum and a combination of both were set to be three different inputs.Artificial neural network with or without convolutional layer were set be two different network structures.The results revealed a convolutional neural network combined with inputs of first and zero-order derivatives was proposed to have the best classification effect on domestic sewage,mixed rainwater,rainwater and industrial sewage.The recognition rate of industrial wastewater was 100%,and the recognition rate of domestic sewage and rainwater mixing system were over 90%.展开更多
Systematic studies on eight isomers of C70O were performed by means of INDO methods It has been indicated that the O atom is mainly added to the C1-C2 or C3-C3 bond and an epoxide feature with C1 symmetry is formed.Ba...Systematic studies on eight isomers of C70O were performed by means of INDO methods It has been indicated that the O atom is mainly added to the C1-C2 or C3-C3 bond and an epoxide feature with C1 symmetry is formed.Based on the optimized geometries,the UV-Vis spectra were calculated.It has been found that the main peaks of C70O resemble those of C70 and the characteristic absorptions beyond 460 nm are produced,which is m agree ment with the experimental results.Theoretical assignments about the absorptions were carried out and the reason for the red-shift of the absorptions was discussed.C70O is probably composed of four isomers according to the calculated results.展开更多
基金supported by the National Natural Science Foundation of China (20501023)the Natural Science Foundation of Guangdong for Doctorial Training Base (5300527)
文摘Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appropriate sulfurization conditions were studied. For the rare earth sulfides with the same crystal structure, the sulfurization temperature showed increasing tendency with the decrease of rare earth element atomic radii. The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. The data showed that the optical band gaps of rare earth sulfides were irregular, and the values ranged from 1.65 to 3.75 eV.
基金Funded by the Foundation of Key Laboratory of Cellulose and Lignocellulosics Chemistry,Guangzhou Institute of Chemistry,Chinese Academy of Sciences (No.LCLC-2010-08)
文摘The interactions of 4-aminosalicylic acid （4-ASA） and surfactants in aqueous solutions were investigated by using UV-Vis spectra and steady-state fluorescence spectroscopy.The results showed that the strongest peak at UV-vis spectra of 4-ASA aqueous solution in the presence of cationic surfactant and cetyltrimethyl ammonium bromide （CTAB） appeared at 206 nm and took a red shift from 206 nm to 221 nm with the increase of 4-ASA concentrations from 0.8×10-5 to 4.4×10-4 mol/L.Similarly,the strongest peak at UV-vis spectra of 4-ASA aqueous solution in the presence of nonionic surfactant and polyvinylpyrrolidone （PVP） appeared at 206 nm and took a red shift from 206 nm to 219 nm with the increase of 4-ASA concentrations from 0.8×10-5 to 4.4×10-4 mol/L.However,the similar phenomena did not appeared in the presence of anion surfactant,sodium dodecyl sulfate （SDS）,the UV-vis spectra of 4-ASA aqueous solution remained the same peak position and the peak value increased with the 4-ASA concentration increase.The results could be attributed to the electrostatic attraction between 4-ASA and CTAB or PVP,as well as the electrostatic repulsion between 4-ASA and SDS.Furthermore,the value of critical micelle concentration （CMC） of surfactants in the presence of 4-ASA was determined with Fluorescence method.The first and second CMC of CTAB was 1.2×10-4 M and 2.4×10-4 M,respectively.The first and second CMC of PVP was 1.2×10-4 M and 2.8×10-4 M.SDS realized the multiple micellizations to form multiple CMC.
文摘Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors have begun to appear in the market. Therefore, it is an urgent need for new techniques to discriminate the genuine and counterfeit Moutai liquor. In this work, the conventional Ultraviolet-Visible (UV-Vis) spectroscopy and two-dimensional correlation UV-Vis spectroscopy are applied to obtain the UV-Vis characteristic of Moutai liquor and counterfeit one, respectively. The experimental results reveal that the conventional UV-Vis spectra of the genuine and counterfeit Moutai liquor are similar. However, the two-dimensional correlation UV-Vis spectra of them are different and this method would be applied to differentiate the counterfeit Moutai liquor from the genuine Moutai liquor. Compared with conventional methods, this novel method has the advantages of easy operation, simple instrumentation and direct recognition, which make it a potential tool in the fields of food safety.
文摘Reactive bright blue rare earth dyestuffs were prepared by using reactive bright blue and lanthanum oxide,praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, dysprosium oxide, erbium oxide, lutetium oxide, yttrium oxide respectively for dyeing silk cloth.The degree of dyeing of reactive bright blue praseodymium and the degree of fixation of reactive bright blue gadolinium are the biggest, and 22.9% and 7 %are increased with that of reactive bright blue respectively.The spectra of reactive bright blue rare earth and reactive bright blue were studied by UV-VIS.In 200.00 ～ 800.00 nm, reactive bright blue has four absorption peaks, reactive bright blue rare earth has three absorption peaks; in 420.00 ～ 760.00 nm, reactive bright blue has two absorption peaks at 661.50 nm and 625.50 nm, respectively, and λmax is 661.50 nm; reactive bright blue rare earth has one absorption peak at 620.50, 618.00, 622.00, 623.00, 622.50, 619.50, 619.00, 621.00, 624.00, 620.00 nm adding La3+ ,Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Dy3+, Er3+, Lu3+, Y3+respectively.
文摘Being widely used as good ligands,xanthates and related compounds have been extensively investigated.However,reports on Pt（Ⅱ） xanthates have been sparse so far.Watt et al.reported the synthesis and characterization of Pt（S;COR）;（R=Me,Et）,but did not provide any absorption spectra of these complexes.We prepared twelve platinum （Ⅱ） xanthate complexes and examined their absorption spectra in detail.
基金the Shanghai Key Subject (China P1501)Science Technology Foundation of Shanghai (064307054)Science Technology Foundation of Shanghai Universities (167)
文摘Reactive blue rare earth dyestuffs were prepared by using reactive blue and lanthanum oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, erbium oxide, lutetium oxide and yttrium oxide respectively for dyeing silk cloth. The degrees of dyeing of reactive blue gadolinium and fixation of reactive blue neodymium were the biggest respectively, were 84.83% and 97.96 respectively, were 24.13% and 8.36% were increased with that of reactive blue respectively. The spectra of reactive blue rare earths and reactive blue were studied by UV-VIS. In 200.00～800.00 nm, the λmax of reactive blue, reactive blue lanthanum, reactive blue praseodymium, reactive blue neodymium, reactive blue samarium, reactive blue europium, reactive blue gadolinium, reactive blue terbium, reactive blue dysprosium, reactive blue erbium, reactive blue lutetium and reactive blue yttrium are 599.00, 600.00, 602.00, 601.00, 600.00, 600.50, 600.50, 601.00, 600.00, 600.50, 599.50 and 600.50 nm respectively. Reactive blue lanthanum, reactive blue praseodymium, reactive blue neodymium, reactive blue samarium, reactive blue europium, reactive blue gadolinium, reactive blue terbium, reactive blue dysprosium, reactive blue erbium, reactive blue lutetium, reactive blue yttrium and reactive blue had almost same color.
基金supported by the National Natural Science Foundation of China(No.21172174)
文摘A bis-2-iminopyrrole compound（1） and its difluoroboron complex（2） were synthesized and characterized. The crystal of 2 is in the monoclinic system, P2_1/n space group with a = 21.5113（15）, b = 6.3036（3）, c = 21.5064（15） A, V = 2826.3（7） A^3, Z = 4, C_（26.5） H_（25） B_2 ClF_4 N_4 O, M_r = 548.57, D_c = 1.390 g/cm, F（000） = 1132 and μ（MoKα） = 1.787 mm^-1. The final R = 0.0647 and wR = 0.1817 for 10346 observed reflections with I 〉 2σ（I）, and R = 0.0889 and wR = 0.1993 for all data. The molecules of complex 2 self-assemble through C–H×××F hydrogen bonds and form tubular structures which are filled by CH_2 Cl_2 molecules stabilized by C–H×××π interaction. The UV-Vis spectra of complex 2 show great bathochromic shift compared to that of compound 1 due to the difluoroboron complexing. Complex 2 shows fluorescence emission both in solid state and in solution, whereas compound 1 only exhibits fluorescence emission in solid state.
基金supported by the National Key R&D Program of China(No.2019YFD1100505)the program of China Scholarship Council(No.201806210101).
文摘Optimizing sewage collection is important for water pollution control and wastewater treatment plants quality and efficiency improvement.Currently,the urban drainage pipeline network is upgrading to improve its classification and collection ability.However,there is a lack of efficient online monitoring and identification technology.UV-visible absorption spectrum probe is considered as a potential monitoring method due to its small size,reagent-free and fast detection.Because the performance parameters of probe like optic resolution,dynamic interval and signal-to-noise ratio are weak and high turbidity of sewage raises the noise level,it is necessary to extract shape features from the turbidity disturbed drainage spectrum for classification purposes.In this study,drainage network samples were online collected and tested,and four types were labeled according to sample sites and environment situation.Derivative spectrum were adopted to amplify the shape features,while convolutional neural network algorithm was established to conduct nonlinear spectrum classification.Influence of input and network structure on classification accuracy was compared.Original spectrum,first-order derivative spectrum and a combination of both were set to be three different inputs.Artificial neural network with or without convolutional layer were set be two different network structures.The results revealed a convolutional neural network combined with inputs of first and zero-order derivatives was proposed to have the best classification effect on domestic sewage,mixed rainwater,rainwater and industrial sewage.The recognition rate of industrial wastewater was 100%,and the recognition rate of domestic sewage and rainwater mixing system were over 90%.
基金supported by the National Natural Science Foundation of China
文摘Systematic studies on eight isomers of C70O were performed by means of INDO methods It has been indicated that the O atom is mainly added to the C1-C2 or C3-C3 bond and an epoxide feature with C1 symmetry is formed.Based on the optimized geometries,the UV-Vis spectra were calculated.It has been found that the main peaks of C70O resemble those of C70 and the characteristic absorptions beyond 460 nm are produced,which is m agree ment with the experimental results.Theoretical assignments about the absorptions were carried out and the reason for the red-shift of the absorptions was discussed.C70O is probably composed of four isomers according to the calculated results.
