Excitation and emission spectra of new borate La_2CaB_(10)O_(19) doped Eu^(3+) in VUV-VIS range, high resolution (emission) spectra at room temperature and lifetime of Eu^(3+) were investigated. The emission line at a...Excitation and emission spectra of new borate La_2CaB_(10)O_(19) doped Eu^(3+) in VUV-VIS range, high resolution (emission) spectra at room temperature and lifetime of Eu^(3+) were investigated. The emission line at about 616 nm attributed to the (()~5D_0)-(()~7F_2) transition of Eu^(3+) is the most intense emission of Eu^(3+). The broad band at about 244 nm is originated from charge transition band (CTB) of O^(2-)→Eu^(3+). According to the numbers of spectral lines (()~5D_0)-(()~7F_0) and (()~5D_0)-(()~7F_1) in high-resolution spectrum, Eu^(3+) ions occupy two crystallographic sites. The lifetimes of (()~5D_0)-(()~7F_0) transition of Eu^(3+) of two kinds of lattice sites are individually 2.1 and 2.6 ms, and both are exponential decay. In the VUV excitation spectrum, complicated band between 130 and 170 nm consists of host absorption and f-d transition of Eu^(3+).展开更多
The C^2Π-X^2Π(0,0)band of AgO has been reinvestigated by laser induced fluorescence spectroscopy with a spectral resolution of ~0.02 cm^−1.The AgO molecules are produced by discharging a gas mixture of O2/Ar with si...The C^2Π-X^2Π(0,0)band of AgO has been reinvestigated by laser induced fluorescence spectroscopy with a spectral resolution of ~0.02 cm^−1.The AgO molecules are produced by discharging a gas mixture of O2/Ar with silver needle electrodes in a supersonic jet expansion.By employing a home-made narrowband single longitude mode optical parametric oscillator(SLM-OPO)as the laser source,high-resolution spectra of the C^2Π-X^2Π(0,0)band have been recorded for both 107Ag16O and 109Ag16O isotopologues.The spectroscopic constants of the C^2Π state are consequently determined,with the 109Ag16O one being reported for the first time.The nature of the spin-orbit coupling effect in the C^2Π state is proposed to be due to state mixing with the nearby repulsive 4Σ− and 4Π states.展开更多
Salvianolic acid A(Sal A),a water-soluble ingredient in Danshen,has various biological activities.Sal A and its impurities have similar physical and chemical properties,as well as strong reducibility;therefore,they ar...Salvianolic acid A(Sal A),a water-soluble ingredient in Danshen,has various biological activities.Sal A and its impurities have similar physical and chemical properties,as well as strong reducibility;therefore,they are difficult to prepare and purify.In this study,high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography.Furthermore,HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis,ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product.The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry,and their contents were quantified as well.Following the principles of ISO Guides 34:2009 and 35:2005,a Sal A reference material was certified,covering homogeneity studies,stability studies,characterization,and uncertainty estimations.展开更多
文摘Excitation and emission spectra of new borate La_2CaB_(10)O_(19) doped Eu^(3+) in VUV-VIS range, high resolution (emission) spectra at room temperature and lifetime of Eu^(3+) were investigated. The emission line at about 616 nm attributed to the (()~5D_0)-(()~7F_2) transition of Eu^(3+) is the most intense emission of Eu^(3+). The broad band at about 244 nm is originated from charge transition band (CTB) of O^(2-)→Eu^(3+). According to the numbers of spectral lines (()~5D_0)-(()~7F_0) and (()~5D_0)-(()~7F_1) in high-resolution spectrum, Eu^(3+) ions occupy two crystallographic sites. The lifetimes of (()~5D_0)-(()~7F_0) transition of Eu^(3+) of two kinds of lattice sites are individually 2.1 and 2.6 ms, and both are exponential decay. In the VUV excitation spectrum, complicated band between 130 and 170 nm consists of host absorption and f-d transition of Eu^(3+).
基金the the National Natural Science foundation of China(No.21773221 and No.21727804)the National Key RD Program of China(2017YFA0303502)the Fundamental Research Funds for the Central Universities of China(No.WK2340000078).
文摘The C^2Π-X^2Π(0,0)band of AgO has been reinvestigated by laser induced fluorescence spectroscopy with a spectral resolution of ~0.02 cm^−1.The AgO molecules are produced by discharging a gas mixture of O2/Ar with silver needle electrodes in a supersonic jet expansion.By employing a home-made narrowband single longitude mode optical parametric oscillator(SLM-OPO)as the laser source,high-resolution spectra of the C^2Π-X^2Π(0,0)band have been recorded for both 107Ag16O and 109Ag16O isotopologues.The spectroscopic constants of the C^2Π state are consequently determined,with the 109Ag16O one being reported for the first time.The nature of the spin-orbit coupling effect in the C^2Π state is proposed to be due to state mixing with the nearby repulsive 4Σ− and 4Π states.
基金The authors acknowledge National Key R&D Program of China(Grant No.2016YFC1000900)The Drug Innovation Major Project(Grant No.2018ZX09711001-001-015)should be substituted by Drug Innovation Major Project(Grant No.2018ZX09711001-003-022)CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-3-007)for financing this work.
文摘Salvianolic acid A(Sal A),a water-soluble ingredient in Danshen,has various biological activities.Sal A and its impurities have similar physical and chemical properties,as well as strong reducibility;therefore,they are difficult to prepare and purify.In this study,high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography.Furthermore,HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis,ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product.The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry,and their contents were quantified as well.Following the principles of ISO Guides 34:2009 and 35:2005,a Sal A reference material was certified,covering homogeneity studies,stability studies,characterization,and uncertainty estimations.
