新席夫碱吡哆醛缩邻氨基酚的合成及其分析应用研究

本文研究了新席夫碱吡哆醛缩邻氨基酚的合成及其分析应用，提出了钒（Ｖ）的分光光度测定法，该法简便，灵敏，选择性好。     

Underpotential deposition of tin(II) on a gold disc electrode and determination of tin in a tin plate sample

This work describes a study of the underpotential deposition (UPD) of Sn²⁺ on a polycrystalline gold disc electrode using cyclic voltammetry (CV) and chronocoulometry (CC). Sn²⁺ ions showed well-defined peaks from UPD and UPD stripping (UPD-S) in 1 mol/L HCl solutions, while bulk deposition (BD) and BD stripping (BD-S) of the ions were also observed. The measured UPD shifts, E_UPD, between the UPD-S and the BD-S peaks were more than 200 mV. The UPD charge and the surface coverage of tin were measured by CC. A new method for determining Sn²⁺ was therefore developed, based on the excellent electrochemical properties of the Au/Sn UPD system. A plot of the UPD-DPASV (differential pulse anodic stripping voltammetry) signal versus the Sn(II) concentration was obtained for [Sn(II)] of 1.98×10^–7 to 3.64×10^–5 M. The method developed here has been applied to determine the tin in a tin plate sample.     

氨基羧酸纤维分离富集-电感耦合等离子体原子发射光谱法测定多种痕量稀土元素

本文制备了氨基羧酸纤维滤纸片作为柱填充物，成功地分离和富集了地化样品中的多种稀土元素。富集后的稀土元素采用电感耦合等离子体原子发射光谱法测定，回收率为90％～109％。本文还对基体干扰及其消除进行了研究。     

Synthesis and characterization of the non-Kekulé, singlet biradicaloid Ar'Ge(micro-NSiMe(3))(2)GeAr' (Ar' = 2,6-Dipp(2)C(6)H(3), Dipp = 2,6-i-Pr(2)C(6)H(3))

Reaction of Ar'GeGeAr' (1) with an excess of Me3SiN3 gives the non-Kekulé, biradicaloid Ar'Ge(mu-NSiMe3)2GeAr' (3, Ar' = 2,6-Dipp2C6H3, Dipp = 2,6-i-Pr2C6H3) which has a planar Ge2N2Si2 array and pyramidal geometry at the germaniums. DFT calculations for the model MeGe(mu-NSiH3)2GeMe indicate no Ge-Ge bonding and a singlet ground state. The calculated energy difference between the optimized singlet and triplet states is 17.51 kcal/mol.     

Cu（Ⅱ）—胱氨酸络合物吸附波的研究及蛋白质中胱氨酸的测定

研究了Cu(Ⅱ)-胱氨酸络合物极谱波的性质;提出了一种用示波极谱法测定蛋白质中胱氨酸的新方法,可在8.0×10~(-4)mol/L Cu~(2+)+8.0×10~(-3)mol/L三乙醇胺的溶液中测定0.05～20mg/L的胱氨酸。     

双质谱测定地卟啉取代基组成的解析方法及其应用

根据卟啉标样的双质谱特征，建立一种计算卟啉环上取代基组成的方法。卟啉的平均分子结构简式衡量其取代基的组成，尤其对地质体中相同碳数的卟啉“混合物”大环外取代基的构成十分有效。     

Voltammetric behavior and determination of bismuth on sodium humate modified carbon paste electrode

The preconcentration and voltammetric behavior of Bi^III on a sodium humate modified carbon paste electrode was studied by means of cyclic voltammetry (CV) and differential pulse stripping voltammetry (DPSV). The proposed measurement involves an initial nonelectrolytic preconcentration step in which Bi^III is complexed by the surface modifier in a solution of 0.05 M KNO₃-0.0106 M HNO₃ (pH 2.0) and a subsequent electrochemical scan step in which the preconcentrated Bi^III was reduced and then oxidized promptly in supporting electrolyte of 0.5 M HNO₃. The resulting DPSV anodic current was proportional to the concentration of Bi^III ion over the range of 4.78 × 10⁻⁸–1.44 × 10⁻⁵ M. The detection limit was 4.78 × 10⁻⁸ M. The proposed method was used to determine bismuth in various samples. Various factors affecting the electrode behavior were also investigated at the same time.     

Reactivity of Ar'GeGeAr' (Ar' = C6H3-2,6-Dipp2, Dipp = C6H3-2,6-iPr2) toward alkynes: isolation of a stable digermacyclobutadiene

The first reactions of the "digermyne" Ar'GeGeAr' (1, Ar' = C6H3-2,6-Dipp2, Dipp = C6H3-2,6-iPr2) with alkynes are reported. 1 reacts with 1 equiv of H5C6CCC6H5 to afford the 1,2-digermacyclobutadiene 2 in high yield, while it reacts with 2 equiv of the less hindered alkyne Me3SiCCH to yield an unexpected bicyclic compound 3. Molecular structures of 2 and 3 were determined by X-ray crystallography. A possible mechanism for the formation of 3 is discussed. The high reactivity of 1, even at room temperature, emphasizes the fundamental differences between the GeGe and CC multiple bonds.     

Application of supercritical fluid extraction coupled with counter–current chromatography for extraction and online isolation of unstable chemical components from Rosa damascena

Supercritical fluid extraction (SFE) coupled with high‐speed counter‐current chromatography (HSCCC) was successfully used for the extraction and online isolation of the unstable compounds from Rosa damascene in a single extraction and separation operation in two stages. The solvent systems of SFE/HSCCC were optimized with the help of multiexponential function model. At the first stage, the upper phase of the solvent system of n‐butanol–tert‐butyl methyl ether–acetonitrile–0.1% aqueous TFA (1.7:1.0:0.8:4.0, v/v/v/v) was used as both the SFE entrainer and the HSCCC stationary phase, and the target compounds were eluted with the corresponding lower phase to separate the hydrophobic compounds. At the second stage, the upper phase of the solvent system of n‐hexane–ethyl acetate–methanol–water (3.2:1.0:2.8:2.6, v/v/v/v) was used as both the SFE entrainer and the HSCCC stationary phase, followed by elution with the corresponding lower phase to separate the moderate hydrophobic compounds. Six compounds including formononetin, delphinidin, cyaniding, 5,6,4′‐trihydroxy‐7,8‐dimethoxy flavone, 5,3′‐dihydroxy‐7,8‐dimethoxy flavone, and 5‐hydroxy‐6,7,8,3′,4′‐pentamethoxy flavone were successfully separated in one extraction–separation operation within 300 min. The targeted compounds were identified by MS and NMR spectroscopy. This research has opened up great prospects for industrial application of SFE/HSCCC to the extraction and separation of unstable compounds.     

Synthesis of LiNi1/3Co1/3Mn1/3O2 cathode material by a modified sol–gel method for lithium-ion battery

LiNi_1/3Co_1/3Mn_1/3O₂ was prepared by a modified sol–gel method, selecting ethylene diamine tetraacetic acid and citric acid as the co-chelating agent. The mole ratios of ethylene diamine tetraacetic acid (EDTA) to metal ion (Mⁿ⁺) were 0:1, 1:1 and 2:1. The obtained samples were characterized by XRD, BET and SEM. The XRD showed that LiNi_1/3Co_1/3Mn_1/3O₂ had good crystallinity and well-ordered layered structure. After calcined at 850 °C, the LiNi_1/3Co_1/3Mn_1/3O₂ particles exhibited a three-dimensional space network structure, which was greatly correlated with the ratio of EDTA to metal ion. The LiNi_1/3Co_1/3Mn_1/3O₂ obtained from a mole ratio of 1:1 (EDTA:Mⁿ⁺) had the best electrochemical performance. The reversible capacities were reached 168 and 100 mAh/g at 1C and 10C discharge rate, respectively. The result of the cycling performance showed a high capacity maintenance ratio of 89.3 % at 1C and 25 °C after 50 cycles. The further electrochemical performance was evaluated by electrochemical impedance spectroscopy and cyclic voltammetry.