In this work, a sensitive, rapid and simple method for the determination of trace amounts of potassium ferrocyanide in salinized foods and table salt using EV as a RRS probe is established. The detection limit (3σ)...In this work, a sensitive, rapid and simple method for the determination of trace amounts of potassium ferrocyanide in salinized foods and table salt using EV as a RRS probe is established. The detection limit (3σ) of the EV system is 7.8 ng/mL. This new method is more suitable for the determination of the trace amounts of potassium ferrocyanide in colour salinized foods and it can not be disturbed by the color of salinized foods.展开更多
In a pH=0.65―1.5 NaAc-HCl medium, methylene blue(MB) reacts with 12-tungstophosphoric acid (TPA) by virtue of electrostatic attraction and hydrophobic force to form a 3:2 ion-association complex. As a result, th...In a pH=0.65―1.5 NaAc-HCl medium, methylene blue(MB) reacts with 12-tungstophosphoric acid (TPA) by virtue of electrostatic attraction and hydrophobic force to form a 3:2 ion-association complex. As a result, the intensities of resonance Rayleigh scattering(RRS), second-order scattering(SOS) and frequency doubling scatte- ring(FDS) are enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS are located at 316, 647 and 311 nm. The increments of scattering intensity(△I) are directly proportional to the concentration of MB in a certain range. The methods exhibited high sensitivity, and the detection limits(3s) for MB are 2.3 ng/mL(RRS method), 5.6 ng/mL(SOS method) and 6.4 ng/mL(FDS method), respectively. The effects of coexisting substances have been examined, and the results indicate that the methods have good selectivity. Based on the above researches, a new spectral method for the determination of trace amounts of MB has been developed. It can be applied to the determination of MB in human serum, and the recoveries are 97.5%―105.0%. The results are in good agreement with those obtained by the pharmacopoeia method. In this work, the optimum conditions of the reaction and the influencing factors were investigated. In addition, the reaction mechanism and the reasons of the enhancement of resonance light scattering were discussed.展开更多
In a pH 2.4 Britton-Robinson buffer medium, the anthracycline antibiotics mitoxantrone(MXT) could react with metal ions such as Pd(Ⅱ), Co(Ⅱ) and Cu(Ⅱ) to form 1:2(molar ratio) cationic chelates, which fu...In a pH 2.4 Britton-Robinson buffer medium, the anthracycline antibiotics mitoxantrone(MXT) could react with metal ions such as Pd(Ⅱ), Co(Ⅱ) and Cu(Ⅱ) to form 1:2(molar ratio) cationic chelates, which further reacted with the anionic dye titan yellow to form 1:2 ternary ion-association complexes by electrostatic interaction. As a result, the intensity of resonance Rayleigh scattering(RRS) was enhanced greatly. These RRS spectral characteristics of various metal ion systems were similar, and the maximum RRS wavelengths were all located at 454 nm. But the increments of RRS intensities were different in the series of Pd(Ⅱ)〉Co(Ⅱ)〉Cu(Ⅱ). The enhanced RRS intensities were proportional to the concentration of MXT in a range of 0.03-2.4μg/mL and the detection limit(3σ) was 0.009μg/mL for the Pd(Ⅱ) system. In this study, the optimum conditions of the reactions and the effects of foreign substances were investigated, in addition, the composition and reaction mechanism of ion-association complexes were discussed. Thus a highly sensitive, simple and rapid method is proposed for the determination of MXT in urine and serum samples.展开更多
In 0.1 mol/L HCl medium, 12-tungstophosphoric(TP) acid reacted with matrine(Mat) and oxymatrine(Oxy) to form an ion-association complex. As a result, the new spectra of resonance Rayleigh scattering(RRS), seco...In 0.1 mol/L HCl medium, 12-tungstophosphoric(TP) acid reacted with matrine(Mat) and oxymatrine(Oxy) to form an ion-association complex. As a result, the new spectra of resonance Rayleigh scattering(RRS), second-order scattering(SOS) and frequency doubling scattering(FDS) appeared and their intensities were enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS were located at 370, 670 and 390 nm, respectively. The in-crements of scattering intensity were directly proportional to the concentration of Mat and Oxy in a certain range. Based on this, the method for the determination of matrine and oxymatrine has been established. It has been applied to the determination of matrine and oxymatrine in samples of Radix sophorae flavescentis with satisfactory result. The reaction mechanism and reasons of RRS enhancement were discussed.展开更多
In pH 4.8 Britton-Robinson (B-R) buffer solution, Mercaptopurine (MP) could react with Cu(II) to form stable chelate compound, a new Resonance Rayleigh scattering (RRS) spectrum generated and enhanced for the binary s...In pH 4.8 Britton-Robinson (B-R) buffer solution, Mercaptopurine (MP) could react with Cu(II) to form stable chelate compound, a new Resonance Rayleigh scattering (RRS) spectrum generated and enhanced for the binary system which the highest peak located at 453 nm as detection wavelength. But the RRS spectra could be quenched after adding her- ring milt DNA (hsDNA), salmon milt DNA (sDNA) and calf thymus DNA (ctDNA) into the binary system, respect- tively. And the weakened degree of spectra was directly proportional to the concentration of DNA. The reaction product of three nucleic acid system have identical spectral features, their range of linearity for the relation of spectral intensity with concentration respectively are 0.05 - 0.9 μg.mL-1 for hsDNA, 0.1 - 0.9 μg.mL-1 for sDNA and 0.3 - 0.9 μg.mL-1 for ctDNA;their detection limit respectively are 5 ng.mL-1for hsDNA, 6 ng.mL-1for sDNA, 6 ng?mL-1 for ctDNA. So a new method for determination of DNA was developed and successfully applied to determine the content of the DNA in artificial synthetized samples. At the same time the spectral features of absorption spectra and RRS spectra of the three reaction system, and the eligible reaction conditions and influencing factors were investigated in this paper.展开更多
This paper deals with the influences of pH, acidity and ionic intensity of the solutions on the resonance Rayleigh scattering spectra and fluorescence spectra of humic acid. When the pH value is low and the acidity an...This paper deals with the influences of pH, acidity and ionic intensity of the solutions on the resonance Rayleigh scattering spectra and fluorescence spectra of humic acid. When the pH value is low and the acidity and ionic intensity are high, the resonance Rayleigh spectra and fluorescence spectra both show a tendency of increasing, though the former's intensity is much higher. In combination with the transmission electron microscope data, the factors leading to the occurrence and enhancement of the resonance Rayleigh scattering spectra of humic acid were explored. It is considered that particle enlargement caused by aggregation, the increase of heterogeneity, the increase of hydrophobility, the formation of interface, etc., are the factors leading to the occurrence and enhancement of the resonance Rayleigh scattering spectra of humic acid. As the intensity of the resonance Rayleigh scattering spectra of humic acid is much higher, resonance Rayleigh scattering spectroscopy can be used as a newly developed spectrum technology, which is more sensitive and simpler, to study humic acid and its complicated behaviors.展开更多
The dynamic stability of axially moving viscoelastic Rayleigh beams is pre- sented. The governing equation and simple support boundary condition are derived with the extended Hamilton's principle. The viscoelastic ma...The dynamic stability of axially moving viscoelastic Rayleigh beams is pre- sented. The governing equation and simple support boundary condition are derived with the extended Hamilton's principle. The viscoelastic material of the beams is described as the Kelvin constitutive relationship involving the total time derivative. The axial tension is considered to vary longitudinally. The natural frequencies and solvability condition are obtained in the multi-scale process. It is of interest to investigate the summation parametric resonance and principal parametric resonance by using the Routh-Hurwitz criterion to obtain the stability condition. Numerical examples show the effects of viscos- ity coefficients, mean speed, beam stiffness, and rotary inertia factor on the summation parametric resonance and principle parametric resonance. The differential quadrature method (DQM) is used to validate the value of the stability boundary in the principle parametric resonance for the first two modes.展开更多
Nonlinear instability in electrically charged jets is studied using the governing electro-hydrodynamic equations describing stretching and thinning of a liquid jet. A jet flow system subject to both space and time evo...Nonlinear instability in electrically charged jets is studied using the governing electro-hydrodynamic equations describing stretching and thinning of a liquid jet. A jet flow system subject to both space and time evolving disturbances is considered. At the linear stage, the Rayleigh and conducting jet flow instability modes are uncovered.Nonlinear instability in the flow is explored via triad resonant waves which uncover favorable operating modes not previously detected in the linear study of the problem. In particular, the jet radius is significantly reduced, and the electric field of the jet is properly oriented under the nonlinear study. It is found that taking into account the resonance triad modes provides a better mathematical description of a jet that stretches and thins due to tangential electric field effects. Both linear and nonlinear instability results in the jet flow system are presented and discussed.展开更多
基金supported by the National Natural Science Foundation of China(No.20475045)Scientific Research Foundation of Bureau of Quality and Technical Supervision of China(No.2005 J0095).
文摘In this work, a sensitive, rapid and simple method for the determination of trace amounts of potassium ferrocyanide in salinized foods and table salt using EV as a RRS probe is established. The detection limit (3σ) of the EV system is 7.8 ng/mL. This new method is more suitable for the determination of the trace amounts of potassium ferrocyanide in colour salinized foods and it can not be disturbed by the color of salinized foods.
基金Supported by the National Natural Science Foundation of China(No.20875078)the Fund of Chongqing Municipal Key Laboratory on Luminescence and Real-Time Analysis China(No.2006CA8006)
文摘In a pH=0.65―1.5 NaAc-HCl medium, methylene blue(MB) reacts with 12-tungstophosphoric acid (TPA) by virtue of electrostatic attraction and hydrophobic force to form a 3:2 ion-association complex. As a result, the intensities of resonance Rayleigh scattering(RRS), second-order scattering(SOS) and frequency doubling scatte- ring(FDS) are enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS are located at 316, 647 and 311 nm. The increments of scattering intensity(△I) are directly proportional to the concentration of MB in a certain range. The methods exhibited high sensitivity, and the detection limits(3s) for MB are 2.3 ng/mL(RRS method), 5.6 ng/mL(SOS method) and 6.4 ng/mL(FDS method), respectively. The effects of coexisting substances have been examined, and the results indicate that the methods have good selectivity. Based on the above researches, a new spectral method for the determination of trace amounts of MB has been developed. It can be applied to the determination of MB in human serum, and the recoveries are 97.5%―105.0%. The results are in good agreement with those obtained by the pharmacopoeia method. In this work, the optimum conditions of the reaction and the influencing factors were investigated. In addition, the reaction mechanism and the reasons of the enhancement of resonance light scattering were discussed.
基金Supported by Education Committee of Chongqing City, China(No.KJ081306)
文摘In a pH 2.4 Britton-Robinson buffer medium, the anthracycline antibiotics mitoxantrone(MXT) could react with metal ions such as Pd(Ⅱ), Co(Ⅱ) and Cu(Ⅱ) to form 1:2(molar ratio) cationic chelates, which further reacted with the anionic dye titan yellow to form 1:2 ternary ion-association complexes by electrostatic interaction. As a result, the intensity of resonance Rayleigh scattering(RRS) was enhanced greatly. These RRS spectral characteristics of various metal ion systems were similar, and the maximum RRS wavelengths were all located at 454 nm. But the increments of RRS intensities were different in the series of Pd(Ⅱ)〉Co(Ⅱ)〉Cu(Ⅱ). The enhanced RRS intensities were proportional to the concentration of MXT in a range of 0.03-2.4μg/mL and the detection limit(3σ) was 0.009μg/mL for the Pd(Ⅱ) system. In this study, the optimum conditions of the reactions and the effects of foreign substances were investigated, in addition, the composition and reaction mechanism of ion-association complexes were discussed. Thus a highly sensitive, simple and rapid method is proposed for the determination of MXT in urine and serum samples.
基金Supported by the National Natural Science Foundation of China(No.20875078)
文摘In 0.1 mol/L HCl medium, 12-tungstophosphoric(TP) acid reacted with matrine(Mat) and oxymatrine(Oxy) to form an ion-association complex. As a result, the new spectra of resonance Rayleigh scattering(RRS), second-order scattering(SOS) and frequency doubling scattering(FDS) appeared and their intensities were enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS were located at 370, 670 and 390 nm, respectively. The in-crements of scattering intensity were directly proportional to the concentration of Mat and Oxy in a certain range. Based on this, the method for the determination of matrine and oxymatrine has been established. It has been applied to the determination of matrine and oxymatrine in samples of Radix sophorae flavescentis with satisfactory result. The reaction mechanism and reasons of RRS enhancement were discussed.
文摘In pH 4.8 Britton-Robinson (B-R) buffer solution, Mercaptopurine (MP) could react with Cu(II) to form stable chelate compound, a new Resonance Rayleigh scattering (RRS) spectrum generated and enhanced for the binary system which the highest peak located at 453 nm as detection wavelength. But the RRS spectra could be quenched after adding her- ring milt DNA (hsDNA), salmon milt DNA (sDNA) and calf thymus DNA (ctDNA) into the binary system, respect- tively. And the weakened degree of spectra was directly proportional to the concentration of DNA. The reaction product of three nucleic acid system have identical spectral features, their range of linearity for the relation of spectral intensity with concentration respectively are 0.05 - 0.9 μg.mL-1 for hsDNA, 0.1 - 0.9 μg.mL-1 for sDNA and 0.3 - 0.9 μg.mL-1 for ctDNA;their detection limit respectively are 5 ng.mL-1for hsDNA, 6 ng.mL-1for sDNA, 6 ng?mL-1 for ctDNA. So a new method for determination of DNA was developed and successfully applied to determine the content of the DNA in artificial synthetized samples. At the same time the spectral features of absorption spectra and RRS spectra of the three reaction system, and the eligible reaction conditions and influencing factors were investigated in this paper.
基金supported jointly by the National Natural Science Foundation of China (No. 20475045)the Social Development Key Project of Guizhou Province [SY(2010)3035]the Frontier Project under the Knowledge-Innovation Program sponsored by the Institute of Geochemistry, Chinese Academy of Sciences (2006)
文摘This paper deals with the influences of pH, acidity and ionic intensity of the solutions on the resonance Rayleigh scattering spectra and fluorescence spectra of humic acid. When the pH value is low and the acidity and ionic intensity are high, the resonance Rayleigh spectra and fluorescence spectra both show a tendency of increasing, though the former's intensity is much higher. In combination with the transmission electron microscope data, the factors leading to the occurrence and enhancement of the resonance Rayleigh scattering spectra of humic acid were explored. It is considered that particle enlargement caused by aggregation, the increase of heterogeneity, the increase of hydrophobility, the formation of interface, etc., are the factors leading to the occurrence and enhancement of the resonance Rayleigh scattering spectra of humic acid. As the intensity of the resonance Rayleigh scattering spectra of humic acid is much higher, resonance Rayleigh scattering spectroscopy can be used as a newly developed spectrum technology, which is more sensitive and simpler, to study humic acid and its complicated behaviors.
基金Project supported by the National Natural Science Foundation of China(Nos.11202136,11372195,11502147,and 11602146)
文摘The dynamic stability of axially moving viscoelastic Rayleigh beams is pre- sented. The governing equation and simple support boundary condition are derived with the extended Hamilton's principle. The viscoelastic material of the beams is described as the Kelvin constitutive relationship involving the total time derivative. The axial tension is considered to vary longitudinally. The natural frequencies and solvability condition are obtained in the multi-scale process. It is of interest to investigate the summation parametric resonance and principal parametric resonance by using the Routh-Hurwitz criterion to obtain the stability condition. Numerical examples show the effects of viscos- ity coefficients, mean speed, beam stiffness, and rotary inertia factor on the summation parametric resonance and principle parametric resonance. The differential quadrature method (DQM) is used to validate the value of the stability boundary in the principle parametric resonance for the first two modes.
基金Project supported by the National Science Foundation of U.S.A.(No.DMS-0946431)
文摘Nonlinear instability in electrically charged jets is studied using the governing electro-hydrodynamic equations describing stretching and thinning of a liquid jet. A jet flow system subject to both space and time evolving disturbances is considered. At the linear stage, the Rayleigh and conducting jet flow instability modes are uncovered.Nonlinear instability in the flow is explored via triad resonant waves which uncover favorable operating modes not previously detected in the linear study of the problem. In particular, the jet radius is significantly reduced, and the electric field of the jet is properly oriented under the nonlinear study. It is found that taking into account the resonance triad modes provides a better mathematical description of a jet that stretches and thins due to tangential electric field effects. Both linear and nonlinear instability results in the jet flow system are presented and discussed.