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Angular-based spatially resolved laser-induced breakdown spectroscopy: a new technique for the effective enhancement of signals without an external time delay system

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Chinese Science Bulletin 2014年第27期59卷 3377-3384页

作者： Qingyu Lin Xu Wang Guanghui Niu Hongjun Lai Xiaoqin Zhu Kunping Liu Tao Xu Yixiang Duan Research Center of analytical Instrumentation Analytical & Testing Centre Sichuan University College of Chemistry and Bioengineering Hezhou University

In this study, we developed a novel angularbased spatially resolved laser-induced breakdown spectroscopy(ABSR-LIBS) technique. This new method allows the spatially resolved spectroscopic properties of laserinduced plasma to be investigated using different angles and polar distances with a spatially adjustable fiber optics probe. The experimental evaluations suggested that the intensity of the Al signal distributions in the ‘‘side-view''depended greatly on the angle of the collection probe. The location of a collection probe at 50° would facilitate efficient spectral collection and minimize the disturbance of the plasma plume. The spectral signals in the plasma emissions had different distribution at various polar distances using the same collection angle, and the highest signal intensity was observed between 15 and 35 mm polar distances. This ABSR-LIBS technique improved both the LIBS signal and the maximum emission intensity of Al atoms by several times at the best spatial position in our experimental conditions. Furthermore, we successfully obtained well-resolved line emission spectroscopy signals without any external time delay using a nongated spectrometer based on the ABSR-LIBS system. We consider that the ABSR-LIBS technique has great potential for obtaining new insights with laser-induced plasma instruments and it could facilitate the development of a low-cost instrument.

关键词：激光诱导等离子体空间分辨光谱性质时滞系统信号分布技术击穿等离子发射

Synthesis and photoluminescent properties of water-soluble TbF_3 nanoparticles

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Journal of Rare Earths 2011年第11期29卷 1018-1021页

作者：王振领张新磊常加忠李春阳 analytical and testing Center Zhoukou Normal University

Monodispersed and water-soluble TbF3 nanoparticles were synthesized at a relatively low temperature in aqueous solution using citric acid as an additive,and characterized by X-ray diffraction（XRD）,field emission scanning electron microscopy（FE-SEM）,Fourier transform infrared spectra（FTIR）,photoluminescence（PL） spectra and *** as-prepared TbF3 nanoparticles had orthorhombic structure and were composed of monodispersed spherical particles with an average particle size of 50 *** excitation spectrum of TbF3 nanoparticles obtained by monitoring the emission of Tb3＋ at 543 nm was composed of the characteristics f-f transition lines within the Tb3＋ 4f8 *** the UV light irradiation,the emission spectrum exhibited four obvious lines centered at 489,543,589,and 618 nm,which was corresponding to the 5D4→7FJ（J=6,5,4,3） transitions of the Tb3＋ ions in TbF3 nanoparticles.

关键词： Tphotoluminescence TbF3 monodispersed water-soluble rare earths

Quantum Chemistry Calculation of Quercetin-silver Complex

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Chinese Journal of Structural Chemistry 2005年第11期24卷 1340-1346页

作者： JIANG Liu-Yun LIU Yu-Ming analytical and testing Center of Sichuan University Chengdu 610064 China

Three possible molecular structures of quercetin-silver complexes obtained from the reaction of quercetin and Ag^＋ in equivalent molar ratio were designed and optimized by using Gaussian 98 program at the B3LYP/LanL2DZ basis set. Through theoretical analysis, one of the three designed structures is discovered to have the most stable coordination position. Then its geometry structure, natural bond orbital analyses, vibrational frequency and biological activity were performed. The results show that it has good stability and relatively stronger antioxidative activity because it is favorably attacked by O2^-. Therefore theoretical foundation is provided for the development of new quercetin metal complexes with higher activity antioxidants.

关键词： quercetin,silver-complex quantum chemistry

Critical Role of Silicon in Directing the Bio-inspired Mineralization of Gelatin in the Presence of Hydroxyapatite

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Journal of Bionic Engineering 2021年第6期18卷 1413-1429页

作者： Ruijuan Yao Yao Wang Bo Zhang Juan Liu Nihui Zhang Jing He Guolong Meng Bo Jiang Shanling Wang Fang Wu National Engineering Research centre for Biomaterials Sichuan UniversityChengdu 610064China analytical and testing Center Sichuan UniversityChengdu 601165China

Significant progress has been made on understanding the critical role of organic components in directing the collagen *** hypothesize that the inorganic trace elements might also play important role in the mineralization of collagenous *** this aim,we systematically compared the in-vitro biomineralization behaviors of gelatin,gelatin-HA and gelatin-SiHA electrospun *** results indicated that the presence of Si ions played a striking influence on the nucleation behaviors and mineralized *** gelatin-SiHA samples demonstrated more homogeneous nucleation within the gelatin fiber and growth along the fiber direction,in comparison with the heterogeneous nucleation and growth of spherulitic clusters on top of the nanofiber surface,*** *** likely shift of the nucleation mode to the intrafibrillar mineralization in the presence of Si ions led to good alignment of apatite c-axis with the long axis of the nanofiber,resulting in a mineralization process and microstructure that were closer to those in natural *** response analysis indicated that Si incorporation improved the MSC attachment and cytoskeleton *** findings might have important implication in both understanding the complex mechanisms involved in collagen mineralization and optimal designing of advanced bio-inspired materials with potential superior mechanical and biological properties.

关键词： Silicon Hydroxyapatite Biomineralization Electrospinning Nanofiber Gelatin

Study of Oxidation of Glutathione Treated with Hypochlorous Acid by Capillary Electrophoresis

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Chinese Chemical Letters 2001年第7期12卷 623-624页

作者： Xian LUO Jian De LU Xiao Yun FU analytical and testing Center Zhejiang UniversityHangzhou 310027

Capillary electrophoresis (CE) method was developed for the separation and quantification of reduced glutathione (GSH), oxidized glutathione (GSSG) and glutathione sulphonic acid (GSO(3)H). Baseline separation was obtained within five minutes. The effects of reaction time and molar ratio of hypochlorous acid (HOCl) to GSH on the oxidation of GSH were investigated.

关键词： Glutathione oxidation capillary electrophoresis

Simultaneous Determination of Magnolol and Honokiol by Synchronous Fluorescence Spectroscopy

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Chinese Chemical Letters 2006年第12期17卷 1603-1606页

作者： Min ZHANG Li Ming DU analytical and testing Center Shanxi Normal University Linfen 041004

A simple sensitive and quick assay for simultaneously determining magnolol （MOL） and honokiol （HOL） has been described based on their natural fluorescence. This method is based on the fact that synchronous fluorometry could resolve the overlapping of fluorescence spectra, which was aroused by their similar molecular structures. In this work, the synchronous spectrum, maintaining a constant difference of Aλ =10 nm between the emission and excitation wavelengths, has been selected for the determination of HOL and MOL. Under the optimum conditions, the fluorescence intensity is proportional to the concentration of MOL and HOL in solution over the range 0.075-0.7 μg/mL and 0.05-0.9 μg/mL with the detection limit of 0.029 μg/mL and 0.019 μg/mL, respectively. The method was applied to the simultaneous determination of MOL and HOL in pharmaceutical dosage with satisfactory results.

关键词： Magnolol honokiol synchronous fluorometry.

The Retention Behaviors of Benzene and Its Alkyl Homologues in Microemulsion Electrokinetic Chromatography

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Chinese Chemical Letters 2000年第6期11卷 549-550页

作者： Xiao Yun FU Wei YUAN Xiu Zhu XU Jian De LU(analytical and testing Center, Zhejiang University, Hangzhou 310027) analytical and testing Center Zhejiang University Hangzhou 310027 China

The retention behaviors of benzene and its alkyl homologues in microemulsion electrokinetic chromatography were investigated in both anionic and cationic surfactant MEEKC systems. The effects of the composition of microemulsion on retention time and selectivity were studied. A good linear relationship was obtained between log k and the carbon number of alkyl chain.

关键词： microemulsion electrokinetic chromatography alkyl benzene

Separation of Hydrophobic Neutral Compounds by Microemulsion Electrokinetic Chromatography

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Chinese Chemical Letters 1998年第11期9卷 0-0页

作者： Xiao Yun FU Xiu Zhu XU Jian De LU (analytical and testing Center, Zhejiang university, Hangzhou 310027) analytical and testing Center Zhejiang University Hangzhou 310027 China

Microemulsion electrokinetic chromatography (MEEKC) was developed for the separation of hydrophobic neutral compounds. The effects of core phase and co-surfactant on the separations were investigated. Under the selected condition, good resolutions were obtained for the test mixtures. The separation efficiencies were higher than 105 theoretical plates per metre.

关键词： Microemulsion electrokinetic chromatography hydrophobic compounds

Separation of Six Pyridoncarboylxic Acid Derivatives by Micellar and Microemulsion Electrokinetic Chromatography

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Chinese Chemical Letters 2001年第2期12卷 155-156页

作者： Jian De LU Wei YUAN Xiao Yun FU analytical and testing Center Yuquan CampusZhejiang UniversityHangzhou 310027

Micellar and microemulsion electrokinetic chromatography (MEKC & MEEKC) separation of six closely structural pyridoncarboylxic acid derivatives were studied and compared Both anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant hexadecyl-trimethyl ammonium bromide: (CTAB) were used to form micellar and microemulsion as pseudostation phases, respectively. The effects of the separation conditions on retention time and selectivity were studied. Good resolutions were obtained in selected systems. indicating that there is markably different selectivity between SDS and CTAB systems.

关键词： Micellar microemulsion electrokinetic chromatography