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Heat capacity and thermodynamical properties of the crystal of [RE_2(Glu)_2(H_2O)_8](ClO_4)_4·H_2O (RE = Nd, Eu, Dy)

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science china chemistry 2009年第7期52卷 862-867页

作者： WU XinMin1, LI Wei1, TAN ZhiCheng2 & QU SongSheng3 1 Department of Chemical Engineering, Beijing Institute of Petro-chemical Technology, Beijing 102617, china 2 Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of sciences, Dalian 116023, china 3 college of chemistry and molecular science, wuhan university, wuhan 430072, china Department of Chemical Engineering Beijing Institute of Petro-chemical Technology Beijing 102617 China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China college of chemistry and molecular science Wuhan University Wuhan 430072 China

Thermodynamical data of rare earth complexes with amino acid are important for engineering chemistry and fundamental chemistry. However, they have rarely been reported. In this work, a series of crystalline complexes of rare earth perchlorate coordinated with glutamic acid have been synthesized in water medium, and their thermodynamical data, including the heat capacity in low temperature range and the standard enthalpy of formation, were determined. These complexes were identified to be [RE2(Glu)2(H2O)8](ClO4)4·H2O (RE = Nd, Eu, Dy) by using thermogravimetric analysis (TG), differential thermal analysis (DTA), and chemical and elementary analyses. Their purity has been determined. No melting points were observed for all the three complexes. The heat capacity of the complexes was measured by an adiabatic calorimeter from 79 to 370 K. Abnormal heat capacity values were detected for two of the complexes and the decomposition range of one complex was found. The temperature, enthalpy change and entropy change of the decomposition processes of the three complexes were calculated. The polynomial equations of heat capacity in the experimental temperature range have been obtained by least squares fitting. The standard enthalpy of formation was determined by an isoperibol reaction calorimeter at 298.15 K.

关键词： complex of rare earth, [RE2(Glu)2(H2O)8](ClO4)4·H2O (RE = Nd, Eu, Dy Glu = glutamic acid), low-temperature heat capacity, standard enthalpy of formation

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CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

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Chinese Journal of Polymer science 2002年第4期20卷 369-375页

作者： Yun Chen Xiao-peng Xiong Guang Yang Li-na Zhang Sen-lin Lei Hui Liang Electron Microscope Lab of Medical School, wuhan university wuhan 430072, china college of chemistry and molecular sciences, wuhan university, wuhan 430072, china wuhan Univ Coll Chem & Mol Sci Wuhan 430072 Peoples R China wuhan Univ Sch Med Electron Microscope Lab Wuhan 430072 Peoples R China

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

关键词： hydrolysis cellulose acetate thermal stability regenerated cellulose membrane pore size solvent-resistance SEM

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A New PAA Sol-Gel Method to Synthesis the Spinel LiMn_2O_4 Material for Li-ion Battery

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wuhan university Journal of Natural sciences 2002年第1期7卷 97-101页

作者： Zhan Hui, Zhou Yun-hong  college of chemistry and molecular sciences, wuhan university, wuhan 430072, Hubei, china college of chemistry and Molec. Sci. Wuhan University Wuhan 430072 Hubei China

A PAA sol-gel method, which is based on the chelate effect of PAA polymer, was developed for the synthesis of the spinel LiMn 2O 4 material. The pyrolysis process of the PAA-nitrate mixture precursor was investigated by TG and DTA analysis. It is found that the structure and electrochemical properties of the material are sensitive to the atmosphere employed in the synthesis process. Preliminary results show that the material thus prepared has a good electrochemical performance even at high charge and discharge current.

关键词： sol-gel PAA spinel material

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SOLUTION PROPERTIES OF ANTITUMOR CARBOXYMETHYLATED DERIVATIVES OF α-(1→3)-D-GLUCAN FROM GANODERMA LUCIDUM

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Chinese Journal of Polymer science 2001年第3期19卷 283-289页

作者： Li-na Zhang Mei Zhang Jing-hua Chen Fan-bo Zeng Department of chemistry wuhan university, wuhan 430072, china Pharmacy college, Tongji Medical university, wuhan 430072, china wuhan Univ Dept Chem Wuhan 430072 Peoples R China Tongji Med Univ Coll Pharm Wuhan 430072 Peoples R China

Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38～0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or NaOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.

关键词： Solution properties Antitumor activity Carboxymethylated derivative α-D-glucan Ganoderma lucidum

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Chitosan-Pectin Synergistic Interaction and Gelation

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wuhan university Journal of Natural sciences 2001年第4期6卷 826-830页

作者： He Dong bao, Shi Yi, Zhan Dong feng, Fong Feng college of chemistry and molecular science, wuhan university, wuhan 430072, china wuhan university College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.

关键词： chitosan pectin synergistic interaction gelation

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The Electrochemical Properties of Thionine Adsorbed Monolayer on Gold Electrode

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wuhan university Journal of Natural sciences 2001年第4期6卷 846-850页

作者： Fang Cheng, Liu Yue lin, Zhou Xing yao  college of chemistry and molecular science, wuhan university, wuhan 430072, china wuhan university College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

A gold electrode modified with adsorbed thionine monolayer was investigated with ac impedance and cyclic voltammetry method. It was found there were some different redox properties for the adsorbed thionine depended on the different potential scanning rate. At the slower potential scanning rate (10 mV? s?1), the dimer of thionine appeared and possessed the catalytic activity for the oxidation of ascorbic acid. The underpotential deposition (UPD) and the bulk deposition of Cu2+ were also employed to investigate the monolayer of adsorbed thionine.

关键词： Key words thionine monolayer ac impedance voltammetry

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Spectrofluorimetric Determination of Magnesium (Ⅱ) with 7-(8-Hydroxy-3, 6-Disulfonaphthylazo)-8-Hydroxyquinoline-5-Sulfonic Acid

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wuhan university Journal of Natural sciences 2001年第4期6卷 831-835页

作者： Zhang Xian, Wang Hong, Zhang Hua shan college of Chemisitry and molecular science, wuhan university, wuhan 430072, china college of chemistry and molecular science Wuhan University Wuhan China

A new fluorescent reagent, 7 (8 hydroxy 3, 6 disulfonaphthylazo) 8 hydroxyquinoline 5 sulfonic acid (HDNHQ) for the determination of magnesium has been developed. It reacted with magnesium to form a 1∶1 fluorescent complex with λ ex / λ em =356/495 nm immediately at room temperature in ammonia ammonium chloride buffer (pH 10.7). A linear relationship was obtained in the magnesium concentration range of 0 160 ng·mL -1 with the detection limit of 0.04 ng·mL -1 . The proposed method was simple, rapid and sensitive. It has been successfully applied to the determination of trace magnesium in blood serum with recoveries of 103.75% and 98.16%, respectively.

关键词： Hydroxy 3 6 disulfonaphthylazo) 8 hydroxyquinoline 5 sulfonic acid magnesium spectrofluorimetry blood serum

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A New Approach to [60]Fullerene Ferrocenyl Derivative

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Chinese Chemical Letters 2000年第9期11卷 775-776页

作者： Yuan Yin CHEN Xin Hong LI college of chemistry and Environmental science, wuhan university, wuhan 430072 wuhan Univ Coll Chem & Environm Sci Wuhan 430072 Peoples R China

A new approach to fullerene ferrocenyl derivative has been made. [60]Fullerene reacts with ferrocenylmethyl azide to give N-ferrocenylmethyl imino[60]fullerene in 42% yield.

关键词： C-60 ferrocenyl azide synthesis

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The Characteristic of Electrochemical Oxidation of Aniline on SnO_2/Ti Electrode

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wuhan university Journal of Natural sciences 2001年第4期6卷 836-840页

作者： Wang Yu ling, Cai Nai cai , Huo Yao dong, Chen Hao college of chemistry and molecular science, wuhan university, wuhan 430072, china wuhan university College of Chemistry and Molecular Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt electrode. The kinetics factors that influence the oxidation rate of aniline on the SnO 2/Ti electrode are determined by the dissolving of the film on the electrode. The dissolving of the film consisted of intermediate products on the electrode is the slow step. The effects of aniline concentration, pH in aniline solution and the current density( i )on the rate of aniline oxidation, the complexity of intermediate products and the basic category of the intermediate products consisted of the film are introduced.

关键词： electrochemical oxidation SnO 2/Ti aniline

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Synthesis of 2, 6-(substituded)pyridine Derivatives Using Amide and Imine Groups

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Chinese Chemical Letters 2003年第6期14卷 572-574页

作者： Mei Ying LI, Pei Zhi HU*, Wan Ren ZHU, Kuo Xi XU college of chemistry and molecular science, wuhan university, wuhan 430072 college of chemistry and molecular science Wuhan University

A new wo-armed?acyclic diamide Ia 2, 6-bis(1-ethanecarbozamido-2-amino)pyridine, and a new series of aromatic aldehyde schiff bases containing pyridine ring and amide bridge, IIa-f, were prepared. The compounds were characterized by elemental analysis, IR, 1HNMR and MS. The bioactivity half inhibitory concentration C1/2 is given.

关键词： Aromatic aldehyde Schiff bases pyridine amide bridge.

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