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Table of Content

    10 February 2010, Volume 31 Issue 2
    Contents
    Content of Chemical Journal of Chinese Universities Vol.31 No.2(2010)
    2010, 31(2):  0. 
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    Articles
    Synthesis and Magnetic Property of Cyanide-bridged Fe(Ⅲ)-Cu(Ⅱ) Complexes
    CUI Ai-Li, NI Wei-Wei, KOU Hui-Zhong*
    2010, 31(2):  215-220. 
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    Three cyanide-bridged Fe(Ⅲ)-Cu(Ⅱ) complexes derived from[Fe(CN)5L]2-[L=1-methyl-imidazole(1-Meim) or imidazole(Him)] and Cu(Ⅱ) macrocyclic building blocks were synthesized and their crystal structures and magnetic properties were studied. Structural analysis shows that they have one-dimensional chain structures. Each Cu(Ⅱ) ion possesses an elongated coordination geometry with two cyanide nitrogen atoms situated at the trans axial positions, and in turn each Fe(Ⅲ) connects two Cu(Ⅱ) ions with two cyanide ligands, generating alternate chainlike structures. Magnetic measurements show that two complexes display ferromagnetic interaction, and one compound exhibits unusual antiferromagnetic property.

    Synthesis, Crystal Structure and Surface Photovoltage of a Series of Co-M Coordination Polymers(M=Cd, Zn, Co)
    MENG Qin, JIN Jing*, LIU Jia-Cao, NIU Shu-Yun
    2010, 31(2):  221-226. 
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    Three Co-M(M=Cd, Zn, Co) coordination polymers, [CoCd(mal)2(H2O)4]n(1), [CoZn(mal)2(H2O)4]n(2) and [Co2(mal)2(H2O)4]n(3)(mal=malonate), were synthesized by hydrothermal method and structurally characterized by X-ray single crystal diffraction. The structure analysis shows that the three coordination polymers all possess 2D layer structure constructed by mal anion bridging Co(Ⅱ) and M(Ⅱ) ions. The layers are further linked by the hydrogen bonds, producing 3D network structure. The measurement and analysis of surface photovoltage spectroscopy(SPS) and UV-Vis spectra indicate that the three polymers exhibit positive surface photovoltage responses in the range of 300—600 nm, moreover, the SPS also present a consistency with UV-Vis spectra.

    Hierarchical Structure TiO2 Micro/Nanofibers Prepared by Coaxial Electrospinning
    WANG Nü, ZHANG Jing-Nan, CHEN Hong-Yan, ZHAO Yong, CAO Xin-Yu*, ...
    2010, 31(2):  227-230. 
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    In a typical coaxial electrospinning process, we fabricated TiO2 micro/nanofibers with distinct hierarchical structure by controlling the flow rate and the concentration of the inner fluid. There are “microporous”, “vesicle” , “articuliform” and “tube” structure four kinds of typical morphology in the cores of the composite nanofibers. It is a quite simple and powerful method for fabricating hollow fibers with controllable structures, which will have wonderful applications in novel bioinspired materials.

    Interaction of both Indole and Imidazole Group-containing Ruthenium(Ⅱ) Complex with Yeast-RNA
    YANG Huai-Xia, LIU Yan-Ju, ZHAO Lin, WANG Ke-Zhi*
    2010, 31(2):  231-234. 
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    The binding of a novel ruthenium(Ⅱ) complex of [Ru(bpy)(H2iip)2](ClO4)2{bpy=2,2′-bipyridyl, H2iip=2-(1H-indole-3-yl)-1H-imidazo[4,5-f][1,10]-phenanthroline}, to yeast-RNA was investigated by UV-Visible and emission spectroscopy titrations, steady-state emission quenching and competitive binding with ethidium bromide experiments. The results suggest that the binding of this complex to the RNA be intercalative with a binding constant of 7.09×106 L/mol, which is higher than that to calf thymus DNA and the RNA binding constant of an analogous complex [Ru(bpy)2(H2iip)](ClO4)2.

    Synthesis of Ce1-xTixO2 Hollow Nanospheres via Kirkendall Effect
    WANG Zeng-Peng, ZHAO Yong-Nan*, YU Jian-Guo
    2010, 31(2):  235-238. 
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    Ce1-xTixO2 hollow nanospheres were successfully synthesized via the Kirkendall effect under solvothermal conditions, which were characterized by means of XRD, TEM and XPS. The results showed that the hollow nanospheres were 65 nm in sizes, which was smaller than that of the original CeO2 nanospheres. The Ce1-xTixO2 hollow nanospheres were face-centered cubic structure as the same as CeO2 nanospheres. The influences of react temperature and Ti/Ce molar ratio were also discussed. The investigations indicated that high quality hollow nanospheres formed when Ti/Ce molar ratio was 8∶10 at 190 ℃ for 8 h.

    Magnesiothermic Reduction Preparation of Polycrystalline Hexagonal Boron Nitride with Round-flake Morphology
    WANG Ji-Lin, PAN Xin-Ye, GU Yun-Le*
    2010, 31(2):  239-242. 
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    Polycrystalline boron nitride(BN) powders were prepared by magnesiothermic reduction of boron oxide(B2O3) and ammonium chloride(NH4Cl) catalyzed with ferric oxide(Fe2O3) at temperatures ranging from 700 to 850 ℃ under ambient pressure. X-ray diffraction(XRD) result shows a hexagonal phase with lattice parameters a=0.2499 nm and c=0.6682 nm. Fourier transform infrared(FTIR) spectroscopy indicates characteristic absorption peaks of hexagonal BN at 790 and 1380 cm-1. Scanning electron microscopy(SEM) reveals that the submicro-polycrystallites have approximately uniform round-flake morphology with an average diameter of about 0.9 μm and an average thickness of about 100 nm. Catalytic formation mechanism of the product was also discussed.

    Influence of Excitation Intensities on Photoluminescence of ZnO(Wurtzite) Whiskers at Room Temperature
    GUO Xing-Yuan*, DING Zhan-Hui*, ZHAO Xu-Dong, QIU Li-Xia, XUE Yan-Feng, ...
    2010, 31(2):  243-246. 
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    ZnO(wurtzite) whiskers were grown with a floating zone method using ZnO powder as starting materials under 0.3 MPa oxygen pressures. The as-grown samples were characterized by X-ray diffraction and Raman scattering, and their characteristic peaks verify that the as-grown ZnO whiskers have excellent hexagonal wurtzite phase and (100) orientation. The photoluminescence properties of the as-grown ZnO whiskers were measured under 266 nm-light excitation from a Nd∶YAG laser, and the influence of various laser intensity on the photoluminescence of the ZnO whiskers was investigated. It was found that the threshold of UV was higher than 1 kW/cm2.

    Synthesis and Electrochemical Properties of Monoclinic Layered Structure LiMn0.97Al0.03O2-x(PO4)x Materials
    SU Zhi*, XU Mao-Wen, YE Shi-Hai, WANG Yong-Long
    2010, 31(2):  247-252. 
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    Layered lithium manganese bronze LiMn0.97Al0.03O2, LiMnO1.99(PO4)0.01 and LiMn0.97Al0.03O2-x·(PO4)x(x=0.01, 0.03, 0.05) with a monoclinic structure were synthesized by the two-step high temperature solid state reaction and a hydrothermal ion exchange method, using Na2CO3, (CH3COO)2Mn·2H2O, Na3PO4·12H2O and Al2O3 as the starting materials. XRD and SEM were used to characterize the structures and morphology of the precursors and products by the ion exchange reaction. The effect of the doping ions on the structure and the electrochemical performances of the samples was investigated by X-ray photoelectron spectroscopy(XPS), Fourier transform infrared spectroscopy(FTIR), electrochemical impedance spectroscopy(EIS) and chronoamperometry techniques. The results showed the co-doping of Al-PO4 combined the advantages of the improvement of the electrochemical reactivity and the decrease of the electrode reaction resistance by the Al3+ doping, as well as enlarging the unit-cell volume by the PO43- doping. It benefits for the Li+ diffusion in the cathode and the suppression of Jahn-Teller distortion. Comparing the pristine one, the Al-PO4-co-doped LiMnO2 cathode exhibits higher discharge capacity and better cyclic stability.

    Investigation of the Stability and Biocompatibility of HA/ZrO2 Nanocomposite Coatings Prepared by Pulsed Electrochemical Deposition
    WANG Ying-Bo, LU Xiong*, FENG Bo, QU Shu-Xin, WENG Jie
    2010, 31(2):  253-259. 
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    The dense and uniform HA/ZrO2 composite coatings were fabricated on titanium substrates by pulsed electrochemical deposition. The composition, morphologies, biocompatibility and physiological stability of the composite coatings were studied. X-ray diffraction showed Ca8(PO4)4(HPO4)2·5H2O in the coating was converted into hydroxylapatite(HA) and the coating was composed of HA and ZrO2 after heat treatments. Scanning electron microscopy(SEM) indicated that ZrO2 was uniformly distributed in the coatings and the coatings became dense after heat treatments. Atomic absorption spectrometry analysis was used to measure Ca2+ release rate of the coatings immersed in PBS. It was found that the Ca2+ release rate of HA/ZrO2 was lower than that of pure HA coatings. Nanoscratching testing revealed that HA/ZrO2 coatings had better interfacial bonding strength than that of pure HA coatings. Osteoblasts were cultured on the coatings to evaluated the biocompatibility of coatings. The results of the Alamar Blue and ALP test indicated that the composite coatings could favor the proliferation and differentiation of the osteoblasts. In summary, the as-prepared nanocomposite coatings have good biocompatibility.

    Construction and Application of CdTe Quantum Dots-Rhodamine 6G Fluorescence Resonance Energy Transfer Systems
    WANG Xu-Yan, LIANG Jian-Gong, MA Jin-Jie, CHEN Shu-Han, HAN He-You*
    2010, 31(2):  260-263. 
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    Two kinds of thiols modified CdTe quantum dots were used to construct the CdTe quantum dots(donor)-Rhodamine 6G(acceptor) fluorescence resonance energy transfer(FRET) systems, which were applied to investigate the interaction mechanism between CdTe quantum dots and bovine serum albumin(BSA). The results showed that the energy transfer efficiency of the CdTe quantum dots-rhodamine 6G FRET systems were improved, and the distance between CdTe quantum dots and rhodamine 6G(r) were decreased after CdTe quantum dots interacted with BSA, BSA were directly binding to the surface of quantum dot by the coordination between its tryptophan(Trp) residues and the metal.

    Simultaneous Determination of Catechol and Hydroquinone at a Carbon Nanotubes Modified Electrode
    YANG Shao-Ming*, WEI Zhi-Peng, HU Guang-Hui, JIANG Dan, HUANG Ai-Hua, ...
    2010, 31(2):  264-268. 
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    In this paper, carbon nanotubes(CNTs) were dispersed by the use of sodium dodecyl sulfate(SDS). Through layer-by-layer assembly of poly dimethyldiallylammonium chloride(PDDA) and CNTs, PDDA/CNTs multilayer films modified electrode was fabricated on the gold electrodes. PDDA/CNTs multilayer films were characterized by UV-Vis spectroscopy. The electrochemical behavior of the PDDA/CNTs multilayer modified electrode was studied by the cyclic voltammetry(CV) and differential pulse voltammetric(DPV) in the coexistence of the catechol and hydroquinone. The PDDA/CNTs multilayer modified electrode shows the strong electrocatalytic behaviour and electro-separation. The isomers of catechol and hydroquinone were detected at the same time without the separation. The linear range for the determination of catechol and hydroquinone: catechol is 2.0×10-6—1.4 ×10-4 mol/L with the correction coefficient of 0.9991; hydroquinone is 2.0×10-6—1.4×10-4 mol/L with the correction coefficient of 0.9987.

    MALDI-TOF-MS for Lipidomics Analysis——Potential Biomarker for Cadmium Effect on Crucian Carp(Carassius auratus)
    LI Guo-Chen , WANG Yan-Hong*, WU Ren-An, WANG Shi-Cheng
    2010, 31(2):  269-273. 
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    The biochemical effects of cadmium(Cd) on Crucian Carp was studied by MALDI-TOF-MS-based lipidomics. Crucian Carps were exposed to water with 500 μg/L Cd2+ for 0, 10, 20 d, respectively. Muscle samples from Cd-treated fishes were analyzed either by Atomic absorption spectrophotometer(AAS) for Cd contents, or analyzed by HPLC and MALDI-TOF-MS for phospholipids. All MALDI-TOF-MS spectra data were analyzed by pattern recognition using partial least square-discriminant analysis(PLS-DA). During the whole exposure period, Cd contents in muscle kept increasing, while phosphatidylcholine(PC) contents after 10 d exposure were significantly lower than that of normal level(no  exposure)(p<0.05), and the PC contents after 20 d exposure were nor significantly different from the normal level. The three groups were discriminated successfullyby PLS-DA, which suggested that lipidomics studies could better reflect the biochemical effects of Cd. PC could be the biomarker indicating the toxicity of Cd to Crucian Carp. Offline combination of HPLC and MALDI-TOF-MS could not only give the quantify PC, but also isolate and purify PC substraction, hereby it was applicable for lipidomics analysis.

    Simple Method of Protein Detection Based on Double-stranded Fluorescent Aptamer Probe
    GUO Qiu-Ping, YANG Xiao-Hai, WANG Ke-Min*, MENG Xiang-Xian, LI Jun, ZHONG Zhi-Ho
    2010, 31(2):  274-278. 
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    A simple method of protein detection was developed using a double-stranded fluorescent aptamer probe. This double-stranded aptamer probe consisted of an aptamer probe labeled with a fluorophore and a short complementary oligonucleotide labeled with a quencher. In the presence of protein, the double-stranded aptamer probe dissociated and F-aptamer/protein complex was formed, leading to fluorescence restoring. Then protein detection was carried out by monitoring fluorescence enhancement, with a liner range of 6—100 nmol/L and detection limit of 6 nmol/L. This design strategy is easy to generalize for any aptamer without prior knowledge of its secondary or tertiary structure, and would be used as a simple and general tool for protein detection.

    NMR-based Metabonomics Study on Serum and Urine of Hyperthyroidism
    WEI Yang-Yang, WANG Cai-Hong, LI Wei, DONG Ji-Yang*, CHEN Zhong
    2010, 31(2):  279-284. 
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    Nuclear magnetic resonance(NMR) based metabonomics was applied to study the hyperthyroidism by analyzing metabolic profiling of serum and urine. The purpose of this study is to determine an array of characteristic metabolites in serum and urine samples from hyperthyroidism patients and then to interpret these metabolites in possible metabolic pathway. Serum samples from 33 hyperthyroidism patients together with 17 healthy volunteers and urine samples from 53 hyperthyroidism patients with 58 healthy volunteers were collected. Differences in endogenous metabolites were detected on serum and urine samples from the hyperthyroidism group and control group using multivariate statistical analysis. The results show that the hyperthyroidism group has elevated levels of choline, glucose and declined levels of VLDL, LDL, cholesterol, lactate, glycoprotein and alanine in serum samples relative to the healthy group. In urine samples, the hyperthyroidism group show increased levels of glucose, citrate, taurine and creatinine as well as decreased levels of hippurate, trimethylamine-N-oxide, formate and succinate. These results indicate that hyperthyroidism have not only disturbed the carbohydrate metabolism, lipid metabolism and protein metabolism but also influenced energy metabolism, hepatoenteral circulation and gut microflora and caused liver and kidney injury.

    Label Free Proteome Analysis of Plasma from Unstable Angina with Blood Stasis Syndrome Patients
    ZHAO Hui-Hui, YANG Fan, WANG Wei*, WANG Hong-Xia, WEI Kai-Hua*
    2010, 31(2):  285-292. 
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    Label free LC-MS/MS method was used in seeking of unstable angina blood stasis syndrome(UABSS) differentially expressed plasma proteins. A polyclonal antibody affinity column, nanoAcquity UPLC and Synapt HDMS were used on plasma of two classes of samples(12 UABSS patients and 12 health volunteers). The results show that the method has a good reproducibility. The ionic strength coefficient of variability was less than 5%, retention time coefficient of variability was less than 3%. 3843 proteins were detected, among which 24 kinds of proteins differentially expressed large than 1.5 fold, include 11 down-regulated and 13 up-regulated(include 3 kinds of proteins only found in UABSS patients). The dynamic range was about 104. ACTA1, ITIH3 and LBP were only found in the plasma of UABSS patients, Haptoglobin, SAA, CP, C6, MYH11, APOH and ANXA6 were significantly highly expressed in the plasma of UABSS patients, while HBB, HBA, HBE, HBD, HBG, HRG, IGHG, GSN and TF were lowly expressed in the plasma of UABSS patients. These identified increased expressed proteins could be divided into four categories according to their functions: (1) acute phase reactive protein; (2) complement protein; (3) cytoskeletal protein; (4) blood coagulation protein. The decreased expressed proteins could be divided into five categories: (1) apolipoprotein; (2) transport protein; (3) anticoagulated blood protein; (4) immunoglobulin; (5) cytoskeletal modulin protein. In conclusion, UABSS may correlated with inflammatory reaction, lipid metabolic disorder, myocardial damage, blood coagulation factor abnormal, oxygen transport obstacle, and these differentially expressed proteins could provide clues for the study and discovery of new protein targets for antianginal drugs. The label free proteomics is an efficient method for the discovery of differentially expressed proteins of complicated sample.

    Determination of AR Gene Expression in Diabetic Nephropathy
    HE Yong-Xin, LI Xue, FAN Xue-Mei, WANG Wan, WANG Yi-Ming, LUO Guo-An*
    2010, 31(2):  293-295. 
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    Diabetic nephropathy(DN) is a common chronic diabetic microvascular complication. DN is closely related to polyol pathway of glycometabolism, and aldose reductase(AR) is a rate-limiting enzyme in polyol pathway. In order to study the AR expression level in patients with different stages of DN, AR gene expression was detected in 50 cases of normal subjects and 80 diabetic nephropathy patients with different stages. The results show that AR gene is expected to be a biomarker for early diagnosis of DN, as well as the potential drug target in DN treatment. According to AR gene expression, the diagnosis of diabetic nephropathy in Chinese medicine is verified on the molecular biology level.

    Synthesis of Benzimidazole Derivatives in Water Under Imidazolium Salt Grafted Iodobenzene Diacetate Assisted
    WANG Xiao-Ke, TIAN Mi*
    2010, 31(2):  296-302. 
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    We developed a simple and efficient method for the synthesis of benzimidazole derivatives in water. Imidazolium salt grafted iodobenzene diacetate containing double features of ionic liquid and iodobenzene diacetate was synthesized. Thirteen benzimidazole derivatives were synthesized by one-step oxidative cyclisation of 1,2-phenylenediamine or 4-methyl-1,2-phenylenediamine at room temperature and a series of aromatic aldehydes under imidazolium salt grafted iodobenzene diacetate assisted. The reactions were completed in 25—45 min with 92%—98% yields. The structure of products were characterized by 1H NMR and IR, MS spectra and elemental analysis. The synthetic method has such advantages as the broad scope of application of reactants, mild reaction conditions, faster reaction velocity, reasonably good yields, high efficient recycling oxidants and environmental benign. In addition, the possible mechanism of the reaction was proposed.

    Preparation of Series ι-Carrageenan Oligosaccharides and Sequence Determination by Negative-ion Electrospray Tandem Mass Spectrometry
    YANG Bo, YU Guang-Li*, HAO Cui, ZHAO Xia, JI Guo-Li, HU Yan-Nan, WANG Yu-Feng
    2010, 31(2):  303-308. 
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    Ten oligosaccharides were separated from ι-carrageenan mild acid hydrolysate with low pressure gel permeation chromatography(LPGPC). Based on the purity analysis of polyacrylamide gel electrophoresis(PAGE) and high performance thin layer chromatography(HPTLC), the structures of those oligosaccharides were determined by infrared spectrum(IR), nuclear magnetic resonance spectroscopy(NMR) and electrospray mass spectrometry(ESI-MS). Their sequences were confirmed as ι-carrageenan disaccharide to eicosasaccharide with 4-linked-2-O-sulfated-α-D-3,6-anhydrogalactose(A2S) at the reducing and 3-linked-4-O-sulfated-β-D-galactopyranose(G4S) at the non-reducing terminus by electrospray collision-induced dissociation mass spectrometry(ESI-CID-MS/MS). The results show that the structural feature of these ι-carr-oligosaccharides from mild acid hydrolysis is completely different from those neo-ι-carra-oligosaccharides prepared by ι-carra-geenase digestion. All these ι-carrageenan derived oligosaccharides enrich marine carbohydrate library. More importantly, they provide the foundation for the preparation of the oligosaccharide-chip and the investigation on the interaction between oligosaccharide and protein.

    Letter
    Properties of i-Motif Under Molecular Crowding Conditions
    ZHOU Jun, JIA Guo-Qing, FENG Zhao-Chi, LI Can*
    2010, 31(2):  309-311. 
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    i-Motif is formed from two parallel duplexes by intercalating with each other in an antiparallel orientation and each duplex is held together via hemiprotonated cytosine+-cytosine base pairs. However, a cell is crowded with various biomolecules and little is known about the properties of i-Motif under molecular crowding conditions until now. In the present study, we used human telomeric DNA sequence, [C3TA2]3C3, as a model system to investigate such problem by circular dichroism(CD) and UV absorbance spectroscopy. Based on the CD spectra, we found that there were no changes about the structure of i-Motif in the presence of polyethylene glycol(PEG). CD melting results showed that the thermal stability of i-Motif was increased under molecular crowding conditions compare to that in dilute buffer, which was further demonstrated by UV-melting results. This work suggests that molecular crowding could not affect the structure of i-Motif, which may depend on pH, while could enhance the thermal stability of i-Motif.

    Articles
    Constructions of Skeletal and Global Reduced Mechanisms for n-Heptane Complex Chemistry
    JIANG Yong*, QIU Rong
    2010, 31(2):  312-319. 
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    The method of error-propagation-based directed relation graph(DRGEP) was conducted to the reduction of detailed reaction mechanism to the level of skeletal mechanism of n-heptane with specified accuracy. A geometric error propagation strategy applied to this graph accurately identifies the dependencies of specified targets and creates a set of increasingly simplified kinetic schemes containing only the chemical paths deemed the most important for the targets. Two skeletal mechanisms consisting of respectively 69 species involved 690 reactions and 52 species involved 398 reactions with identified threshold value being 0.001 and 0.01 for n-heptane oxidation, was found to mimic the performance of the detailed mechanism with high fidelity. It was found that the algorithm developed for the construction of reduced mechanisms is formally valid when the accompanying relations among the elementary reaction rates are associated with steady state assumptions. An extension of the algorithm was used which can accommodate more general relations. Based on this algorithm, the 30- and 20-species global reduced mechanisms developed was further reduced by CSP to identify the QSS species. High fidelity in simulation was again demonstrated.

    Adsorption of Tetracycline on Marine Sediment
    HU Ji, WANG Jiang-Tao*
    2010, 31(2):  320-324. 
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    Adsorption interactions of tetracycline with marine sediment were investigated under varied pH and salinity and temperatures conditions. Adsorption behavior could be fitted with linear isotherms very well over the concentration range .Adsorption edges were best described with a model, which included interactions between positive form, zwitterion form and negative form of tetracycline and marine sediment interface. It showed that the value of Kd+ was higher than Kd0 and Kd-. The adsorption was favorably influenced by decreasing salinity of seawater, but negatively by increasing temperatures. The result of thermodynamic function calculation showed that the change of Gibbs free energy ΔG0—=-9.746—-9.713 kJ/mol , the enthalpy change ΔH0—=-10.056 kJ/mol and the entropy change ΔS0—<0 for the sorption. It indicated that the adsorption was a spontaneous and exothermic process which accompanied a decrease in the degree of freedom.

    Selective Oxidation of Isobutene to Methacrolein over Molybdenum-based Multiphasic Oxide Catalysts
    QU Yuan-Li, LIU Shi-Yan, WANG Zhen-Lü*, XU Jia-Ning*
    2010, 31(2):  325-329. 
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    The molybdenum-based multiphasic oxide catalysts were prepared and tested in the selective oxidation of isobutylene to methacrolein reaction. The structure and crystal phase of catalysts were characterized by means of XRD, TPR and FTIR methods. The characterization results showed that the adding of bismuth into molybdenum catalysts could enhance the catalytic performance. The adding of iron and cobalt could change the structure and crystal phase of catalysts and significantly improved the conversion of isobutene and selectivity of methacrolein. The results indicate that the synergetic or cooperation effects between multiphasic oxides and the some special phases may be the key role for increasing the catalytic performance. The conversion of isobutene and selectivity of methacrolein can reached 99.9% and 88.7% over the best composed catalyst, respectively.

    Electrodeposition of CuInSe2 and Its Formation Mechanism
    WU Mian-Li, LI Jie*, LIU Fang-Yang, LIU Jun, LAI Yan-Qing, ZHANG Zhi-An, LIU Ye-
    2010, 31(2):  330-335. 
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    In this paper, CuInSe2 thin films were prepared by electrodeposition. The formation mechanism of CuInSe2 was primarily analyzed by cyclic voltammetry(CV), energy dispersive X-ray spectroscopy(EDS) and X-ray diffraction(XRD). The influence of deposition conditions on film stoichiometry, morphology and structure was also investigated. It was shown that the insertion of In into solid phase may proceed underpotential deposition mechanism involving two different routes: In3+ reduction by induced effect of Cu3Se2, and/or reaction with H2Se. The newly generated In and indium selenides may be assimilated into the formation CuInSe2 by reaction with copper selenides. A limiting current was observed at potentials between -0.58—-0.9 V vs. the saturated calomel electrode(SCE) at which smooth and dense CuInSe2 thin films with controllable stoichiometry were obtained. Crystallinity of electrodeposited films was improved largely after annealing.

    Molecular Mechanism Studies on Interactions Between Adenylosuccinate Synthetase and Its Inhibitors
    WANG Yue-Peng, WANG Ming-An, DU Feng-Pei, LI Xiang-Dong, YAO Guang-Wei, ZHANG Pa
    2010, 31(2):  336-342. 
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    By density functional theory B3LYP method with 6-31G(d) basis set, the geometry and electronic structure of the natural inhibitor and derivatives of Adenylosuccinate synthetase(AdSS) were optimized and their thermodynamic stability was also analyzed. The relationship between their electronic structures and bioactivities were discussed based on the Mulliken bond order, atomic net charge distribution and molecular surface electrostatic potential. According to the complex structure of AdSS and its substrate IMP as well as the optimized stable conformation of natural inhibitors, the interaction mode between AdSS and its inhibitors was studied with molecular docking, mechanical optimization and molecular dynamics simulation methods. These results show that the phosphate group and the hydantoin ring of the inhibitors form the pharmacophore model. The van der Waals energy played more important role in binding compared with the electrostatic energy. Furthermore, the inhibitors were mainly located in the hydrophobic cavity of the AdSS.

    Relationship Between Catalytic Activity and Metal Atom Net Charge of Iron Complex Bearing 2-Imino-1,10-phenanthrolinyl Ligand
    DUAN Bao-Gen, KONG Bin, SUN Wen-Hua, YANG Xiao-Zhen*
    2010, 31(2):  343-347. 
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    The metal atom net charge correlation(MANCC) method was used to study catalytic activities of a series of asymmetric iron complexes bearing 2-imino-1,10-Phenanthroliyl ligands for ethylene oligomerization. If the catalytic activity is influenced mostly by electronic effect, it has a good correlation to the metal atom net charge. In general, catalytic activities of iron complexes bearing electron-donating alkyl groups increase with the net charges increasing. On the contrary, with the net charges increasing, catalytic activities decrease while the complexes contain electron-withdrawing halogen groups. Based on the above results, we speculated that two different activated centers probably existed in ethylene oligomerization which are [LFe—R]+ and [LFe—R]2+([Fe(Cl)RL]+). When both the electronic and steric effects of coordinative ligand affect the catalytic activity, the charge difference on the two halogen atoms was correlated with it. And it is found that the cataly-tic activity is improved corresponding to the smaller charge difference.

    Theoretical Study on Isomerization Stability of B4O Molecule
    SHAO Chang-Bin, JIN Lin, DING Yi-Hong*
    2010, 31(2):  348-352. 
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    The recent theoretical studies on the B4O molecule had reported two completely different ground state structures, i.e., a triplet linear structure BBBBO and a singlet triangle structure with an exocylic —BO moiety cB3-BO. In this article, using CCSD(T)/6-311+G(2df)//B3LYP/6-311+G(d) method, we systematically investigated the structures and energetics of various B4O isomers as well as the dissociation and isomerization stability of important species. It was shown that the singlet planar triangle structure containing the —BO unit 11 has the lowest energy, followed by the belt-like B4O isomer 12(10.9 kJ/mol). Both 11 and 12 possess good kinetic stability, and thus might have potential for existence. However, the previously reported triplet linear isomer BBBBO(146.0 kJ/mol) lies energetically much higher than the isomers 11 and 12. The detailed results for B4O reported in this work should provide important information for the growing mechanism of boron oxide clusters as well as the oxidation and doping mechanism of B4 clusters.

    Preparation and Electrochemical Capacitance of α-Co(OH)2 for Supercapacitors
    XIE Li-Jing, JIN Xiao-Qing, FU Guo-Rui, XIE Yu-Long, WANG Yao-Xian, HU Zhong-Ai*
    2010, 31(2):  353-356. 
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    The sheet-like α-Co(OH)2 composed of the uniform nanoparticles was successfully prepared using cobalt chloride as the raw material and polyvinyl pyrrolidone as the dispersant by chemical precipitation method. The components of products were analyzed by FTIR and the structure and morphology were characterized by X-ray diffraction(XRD) and field emission scanning electron microscopy(FESEM), respectively. The electrochemical performances were investigated by cyclic voltammetry and constant current charge/discharge techniques. The test results show that an extraordinary high specific capacitance value of 1220 F/g is achieved, and the α-Co(OH)2 is a promising electrode material for supercapacitor.

    Theoretical Studies on Electronic Structures and Second-order Polarizabilities of Thiazole Derivatives
    TAN Hui, MA Xiao-Hua, LIANG Ran, AI Xi-Cheng*, SUN Meng-Tao*, ZHANG Jian-Ping
    2010, 31(2):  357-360. 
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    Two thiazole-based chromophores were fully optimized with density function theory at B3LYP/6-31G(d) level. Their calculated results are in accordance with the related experiments very well. The parameters which resulted in the difference of the two chromopheres were also calculated with TD-DFT method at the same calculation level. The result indicated that the chromophore(E)-2-(5-(4-(bis(4-methoxyphenyl)amino)styryl)thiazol-2-yl)ethene-1,1,2-tricarbonitrile(TPA-Ti5-TCV) had a larger hyperpolarizability, which was mainly due to its lower ground state to first excited state bandgap caused by the regiochemistry of thiazole.

    Effect of Partly Hydrolyzed Polyacrylamide on the Interfacial Dilational Properties of Alkyl Benzene Sulfonate
    DOU Li-Xia*, CHENG Jian-Bo
    2010, 31(2):  361-366. 
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    The dilational viscoelastic properties of partly hydrolyzed polyacrylamide and alkyl benzene sulfonate in the absence or presence of electrolyte were investigated at the decane water interface by means of longitudinal method and the interfacial tension relaxation method. At low surfactant concentration, the addition of polymer could sharply decrease the dilational elasticity, while it may enhance the dilational elasticity at higher surfactant concentration. Addition of electrolyte possibly compresses the double layer, which leads to a higher dilational elasticity. On the other hand, it also possibly speeds up molecular exchange between the bulk and interface, which results in decreasing the dilational elasticity at low frequency.

    Ionization and Dissociation of Methyl Bromide in Intense Laser Field
    YANG Zheng, LIU Hong-Tao, TANG Zi-Chao, GAO Zhen*
    2010, 31(2):  367-373. 
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    Ionization-dissociation of methyl bromide in intense laser field was studied using home-built reflection time-of-flight mass spectrometer. Based on the relative high resolution of the RTOF-MS(MM>2000), the Kinetic Energy Release(KER) of the fragment ions was measured. Multiphoton dissociation and Coulomb explosion mechanisms were used to explain the experimental results. Comparing with the result of methyl iodide in intense laser field, some differences are observed: (1) at the same laser field intensity, the highest charged fragment ion of methyl bromide was Br3+, lower than I6+ of methyl iodide; (2) the dehydrogenation channel was observed in the multiphoton dissociation or Coulomb explosion of methyl bromide, but was not observed in the case of methyl iodide; (3) HBr+ was observed, but there was no similar channel in the case of methyl iodide; (4) for methyl bromide, the valid charge distance of Coulomb explosion increases with the product of p and q; while in the case of methyl iodide, the distance remained almost the same; (5) the producing channel of CHm+(m=0, 1, 2) is different from the ionization-dissociation of methyl iodide in which the stepwise dissociation of CH3+ was thought to be the main channel, CHm+(m=0, 1, 2) of methyl bromide are mainly from the products of the direct dissociation of the dehydrogenated parent ions instead of the stepwise dissociation of CH3+.

    Selective Inhibition Study of Apicidin Towards Class I HDACs by Molecular Dynamics Simulation
    LI Xiao-Hui*, ZHAO Jun-Wei, TENG Hu, NISHINO Norikazu, XIU Zhi-Long*
    2010, 31(2):  374-378. 
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    The selective inhibitory activity of cyclic tetrapeptides apicidin towards class I histone deacetylases(HDACs) was studied by molecular dynamics simulation. The 3D structure of HDAC1 was constructed by homology modeling using the X-ray structure of HDAC8 as template. Furthermore, the 3500 ps molecular dynamics simulations were performed on both apicidin-HDAC1 and apicidin-HDAC8 complexes, which were obtained by molecular docking. As a result, the Arg270 locating at the entrance of the HDAC1 active pocket played a crucial role in forming stable interactions with apicidin. There were two lasting hydrogen bonds between apicidin and HDAC1 during the molecular dynamics simulation, while none between apicidin and HDAC8. This difference could be another important reason for the high inhibitory activity of apicidin to HDAC1.

    Quantum Chemical Studies on the Damage Mechanism of Hydroxyl Radical to Guanine
    SHEN Yong-Li, HAO Jin-Ku*, CAO Ying-Yu, YANG En-Cui, LIU Shu-Wen
    2010, 31(2):  379-382. 
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    Optimize the molecular structure of guanine with B3LYP/6-31G, the result show that the molecular is a planar structure. Searching the transition state of guanine reacted with hydroxyl radical under UB3LYP/6-31G. Internal reaction coordinate(IRC) calculation was carried under the same theoretical level. The result show that the planar structure is broken by the hydroxyl radical, the hydroxyl radical is added to the carbon-carbon double bond. More exact energies of all the stationary points on the reaction path were calculated under B3LYP/6-31G**. The activation energy was 28.0867 kJ/mol. AIM results showed that the carbon-carbon double bond became weaken in the transition state. The oxigon atom of the hydroxyl radical was bonded with C4 atom.

    Rheological Study of Sol-gel Transition for F68 and F108 in Aqueous Solutions
    TANG Jian-Kai, XIE Yu, SUN Zhao-Yan*, AN Li-Jia
    2010, 31(2):  383-386. 
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    Using the rheology method, the sol-gel transitions of amphiphilic triblock copolymers Pluronic F68(PEO80-PPO30-PEO80) and F108(PEO133-PPO50-PEO133) were studied with increasing the temperature. The “soft gel” regions were found during the sol-gel transition process for the aqueous solutions with some concentrations. It is inferred that the structure of the “soft gel” region by the frequency scanning experiment for F68 aqueous solution.

    Effect of High Magnetic Field on Morphology of Polyoxymethylene
    TENG Ying-Xue, BAN Chun-Yan, CUI Jian-Zhong*
    2010, 31(2):  387-390. 
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    The effect of magnetic field on recrystallization of polyoxymethylene(POM) from the melt was stu-died by means of scanning electronic microscope(SEM), differential scanning calorimetry(DCS), X-ray diffraction(XRD) and Fourier-transform infrared(FTIR) spectrometry, and the mechanism of magnetic process to POM was investigated. The results show that lamellae thickness, lamellae interval, and the melting point of POM are increased under 12 T high magnetic field. The molecule chain is affected and lamella is crystaled along magnetic field.

    Polymer Electrolytes Based on PAMPSLi/P(MMA-VAc)
    NIU Li-Dan, FU Xiang-Kai*, LIU Su-Juan, DU Qiu-Liang
    2010, 31(2):  391-396. 
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    Poly-2-acrylamido-2-methylpropanesulfonic acid lithium(PAMPSLi) and poly-vinylacetate-methyl methacrylate[P(MMA-VAc)] were synthesized. And the polymer electrolytes were prepared by blending PAMPSLi, P(MMA-VAc) and LiClO4. Performances of the copolymer and polymer electrolyte were studied by FTIR, TG, XRD, DMA, SEM, alternating current(AC) impedance andmechanical testing. The results showed that: the crystallization state of the polymer electrolyte changed after blending PAMPSLi with P(MMA-VAc); the cross-linked network changed dense; the thermal stability and tensile strength were improved; the polymer electrolyte membrane had a great number of micro-pores with dimension of 5—10 μm; the ionic conductivity value of the copolymer membrane reached 1.68×10-3 S/cm when n(MMA)∶n(VAc)=2∶8, m(PAMPSLi)∶m[P(MMA-VAc)]=5∶95 and m(LiClO4)∶m(copolymer)=15∶85 at 20 ℃, which did not appear drop by the increase of the LiClO4. And its excellent performance promised the usage of the polymer electrolytes as the ionic conductor material in electrochromic devices(ECD). The mechanism of the conductivity and the thermal stability of polymer electrolyte membrane with the increase of PAMPS was preliminary studied.

    Multiple Relaxation Behavior of Long Chain Branched Polylactic Acid
    WANG Yong-Bin, NIU Yan-Hua, YANG Liang, YU Feng-Yuan, ZHANG Hong-Bin, ...
    2010, 31(2):  397-401. 
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    The long chain branched polylactic acid(PLA) samples were successfully fabricated by high energy irradiation in the presence of a small amount of poly-functional monomer. The branched structures of PLA were convinced by size exclusion chromatography(SEC) coupled with a multi-angle laser light scattering(MALLS). By the means of oscillatory shear and creep measurements, the shear rheological behavior of branched PLA was investigated. Meanwhile, the weighted relaxation spectra of PLA were calculated in light of the combined dynamic modulus data. The multiple relaxation behavior of PLA, which was attributed to the existence of different lengths of long chain branches, was actually observed. In addition, a novel procedure for quantificational determination of the lengths of branches and the arm molecular weight of PLA was put forward. It was found that the lengths of branches of PLA were extended and the arm molecular weight was enhanced with increasing amount of poly-functional monomer. The above results could facilitate the fabrication of long chain branched PLA with well-controlled branched structures and improved rheological properties that may dominate the future bio-plastics industry.

    Synthesis and Characterization of Graft Copolymer PVDF-g-PNIPAAm via ATRP and Its Separating Membranes
    LIN Xian-Kai, FENG Xia, CHEN Li*
    2010, 31(2):  402-405. 
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    The direct graft temperature-sensitive material N-isopropylacrylamide(NIPAAm) on commercial poly(vinylidene fluoride)(PVDF) via atom transfer radical polymerization(ATRP) is demonstrated. The application of ATRP used Copper(Ⅰ) chloride(CuCl)/Tris(2-dimethylaminoethyl)amine(Me6TREN) as the catalyst systems and N,N-dimethylformamide(DMF) as solvent. The graft copolymers of PVDF-g-PNIPAAm were characterized by Fourier transform infrared (FTIR) and 1H NMR spectra. The effects of polymerization temperature and reaction time on grafting ratio were studied. The PVDF-g-PNIPAAm membranes were prepared from the graft copolymers by the phase inversion method. The effect of temperature on the flux of pure water for the PVDF-g-PNIPAAm membrane was investigated. The results show that alkyl fluorides are successfully applied in the ATRP and the PVDF-g-PNIPAAm membranes can exhibit temperature-sensitive performance as the temperature change.

    Electric-sensitive Properties and Mechanism of P(AMPS-co-BMA) Hydrogels
    LIN Song-Bai*, YUAN Cong-Hui, ZHANG Xian, HUANG Bo-Yang
    2010, 31(2):  406-412. 
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    Electric-sensitive hydrogels[P(AMPS-co-BMA)] were prepared by free-radical polymerization with 2-acrylamido-2-methyl propyl sulfonic acid(AMPS) as ionic monomer and (BMA) as non-ionic monomer, using N,N′-methylene bisacrylamide as crosslinking agent, azobisisobutyronitrile as initiator and N,N-dimethyl formamide as solvent, respectively. The swelling properties of hydrogels in deionized water and in NaCl solution were studied in detail. The results show that the swelling rate of the hydrogels increases with the increasing content of AMPS, and the equilibrium swelling ratio of the hydrogels ranges from 236.4 to 298.5. In addition both the deswelling speed and the deswelling extent of the hydrogels decrease with the increasing concentration of polyion in inside of the hydrogels. Moreover, the electrical sensitivity of the hydrogels was studied. The swelling properties of the hydrogels in NaCl solution with an applied voltage were related to the ionic concentration difference between interior hydrogels and exterior NaCl solution. When the concentration of polyion in interior hydrogels is higher than the concentration of NaCl in solution, the hydrogels swells; contrarily, the hydrogels deswells. The bending direction of the hydrogels was also related to the ionic concentration difference between interior hydrogels and exterior NaCl solution. When the concentration of polyion in interior hydrogels is higher than the concentration of NaCl in solution, the hydrogels bend toward cathode; contrarily, the hydrogels bend toward anode. Further investigation shows that the bending speed of the hydrogels also depends on the temperature significantly.

    Preparation and Characterization of pH-Sensitive Polyorganophosphazene Hydrogel
    HONG Ting, LIU Zhi-Ling, ZHOU Yuan-Yuan, CAI Qing*, JIN Ri-Guang
    2010, 31(2):  413-417. 
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    Using N,N-dimethyl-ethylenediamine as cationic substitute and 2-hydroxyethyl methacrylate or allylamine as co-substitute, a kind of pH-sensitive polyorganophosphazenes bearing unsaturated side group was prepared. Their compositions and structures were confirmed by 1H NMR and FTIR analysis. Polyphosphazene gels could be obtained by radical crosslinking the polymers. These gels exhibited different water absorption behavior significantly depending on chemical composition, environmental pH, ion strength and ionic charge. The results revealed the pH-sensitive polyorganophosphazene hydrogels could be good candidates for the study of glucose-mediated insulin release in combination with glucose oxidase.

    Synthesis of Novel Catalyst Based on TiO2/SiO2 for Poly(ethylene terephthalate)
    YIN Ming, FENG Run-Cai, LI Chun-Cheng*, GUAN Guo-Hu, ZHANG Dong, XIAO Yao-Nan
    2010, 31(2):  418-420. 
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    A novel catalyst for the polycondensation of PET based on TiO2/SiO2 sol was synthesized. The composition of the catalysts was characterized by electron probe micro-analyzer(EPMA) and thermogravimetric analysis(TGA) methods. The results indicate that the composition of the catalysts can be well controlled and match well with theoretical values. X-ray photoelectron spectroscopy(XPS) results reveale that caprolactam added into the catalyst has coordinative effects with Ti and gives the catalyst ultra-high activity. The PET products catalyzed by the catalyst with caprolactam had far better properties than those synthesized using traditional antimony based catalysts.