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    24 May 1996, Volume 17 Issue 5
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    Articles
    The Interaction of Vanadyl Ions with G-Actin
    AN Fang, ZHANG Bo-Yan, CNEN Bao-Wei, WANG Kui
    1996, 17(5):  667-671. 
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    The interaction of VO2+ and G-actin was studied by gel-chromatography, fluorescence and CDspectroscopies.The results revealed that for one G-actin molecule, there is one strong-binding site and several weak-binding sites for VO2+, In low molar ratio of VO2+; G-actin vanadyl ions occupy the strong-binding site at first and cause an increase of α-helix content and transformation of the conformation to a more compact one.As the molar ratio increases, vanadyl ions bind to weak-binding sites, but the α-helix content decreases and the conformation becomes rather opened.By measuring light-scattering data as the function of time, the kinetics of G-actin association was studied.In a low concentration, the VO2+ ions, like Mg2+, promote the association, but in case of higher concentration, the effect turns to be inhibitive.However, the nature of linear association is not changed.
    Microwave Radiation Synthesis of Fast Ionic Conductor Na5YSi4O12
    FU Ge-Yan, CUI De-Liang, PANG Huang-Sheng, XU Xiu-Thg, FENG Shou-Hua, XU Ru-Ren
    1996, 17(5):  672-675. 
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    Single phase Na5YSi4O12 which is difficult to be prepared by conventional solid state reaction, was synthesized by microwave radiation synthesis method.The relationship between synthesis conditions and the phases in products was discussed.Acomparison was made of the properties of samples prepared by Sol-Gel method with those by microwave radiation synthesis method,respectively.Compared to conventional Sol-Gel method, the experimental procedure was much simplified and reaction time was shrtened when Na5YSi4O12 was prepared by microwave radiation synthesis method.The sample prepared by microwave method has a particular micro-structure,aggregating state and defect structures, which leads to the decrease of ionic conducting activation energy.
    The Effect of Europium (Ⅲ) on Iron Uptake by Apoferritin
    YANG Bin-Sheng, T. G. St. Pierre, J. Webb
    1996, 17(5):  676-679. 
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    In order to explore the posibility using apoferritin as a cage to synthesize inorganicnanosize particles containing rare earth ions the effect of europium(Ⅲ)on the iron uptake byhorse spleen apoferritin was studied by using absorption spectra.The inhibition of europium(Ⅲ)on iron uptake only affects the initial rate.In the presence of europium(Ⅲ), ferritincan be formed from apoferritin and iron(Ⅱ)in air.
    Synthesis and Properties of Rare Earth Pentafluoropropionate Binuclear Complexes with Stable Radical
    JIANG Zong-Hui, ZHANG Wei, LIAO Dai-Zheng, HUAN Zhen-Wei, QI Yu-Qin, WANG Geng-Lin
    1996, 17(5):  680-68. 
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    Five new complexes of binuclear rare earth(Nd, Gd, Dy, Ho, Er)pentafluoropropionate with μ-2-(4'-chlorobenzoyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide were synthesized and characterized.According to hypersensitive transitions of the complexes (Nd(Ⅲ), Dy(Ⅲ), Ho(Ⅲ), Er(Ⅲ)), it was discussed that for the same ligand the covalency decreases as the atomic number of the rare earth metal atom increases, The observed variable-temperature(4～300 K)susceptibility data for Gd(Ⅲ)complex were fitted to those from theoretical magnetic equation by least-square method.The exchange integral, J, was found to be positive, indicating a weak ferromagnetic spin-exchange interaction between the radical and Gd(Ⅲ)ion.
    Synthesis and Characterization of Liquid Crystal Metal Benzoporphyrins
    WANG Xing-Qiao, CAO Chang-Sheng, GAO Shuang, SHI Tong-Shun, YU Lian-Xiang, CAO Xi-Zhang
    1996, 17(5):  684-686. 
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    In this paper, we describe a much improved synthetic procedure that leads to two new LCbenzoporphyrin──the hitheto unreported p-n-alkoxyl-phenyl-benzoporphyrin.We find out that the appearance and the temperature range of a liquid crystalline phase depend on the length of the side chains.This temperature range is wider than that of octaethanol-porphyrin, These compounds melt to isotropic liquids well below their decomposition point and exhibit a relatively lower viscosity than LC phthalocynine, columar discotic mesophase.
    The Electrochemistry Behaviour of Adsorption of BESOD on Mercury Electrode Surface
    QIAN Wen, MENG Qing-Guo, LUO Qin-Hui, SHEN Meng-Chang
    1996, 17(5):  687-689. 
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    The electrochemical behaviour of bovine erythrocyte superoxide dismutase(BESOD)adsorbed On the mercury electrode surface was reported for the first time by cyclic voltammetry,direct current polarography and double potential-step chronoculoumetry without using mediator.The contribution of diffusion current predominated over adsorption current when the concentration of BESODwas more than 1.0×10-4mol/L.The experimental adsorption isothermal line was in accordance with that calculated by Langmuir equation.The equilibrium constant of adsorptin was 8.96×104 and Gibbs free energy was -28.2kJ/mol.The molecular area(18.06 nm2) of BESODobtained by the electrochemical method, is in good agreement with that(17.36 nm2determined by X-ray crystal structural analysis.
    Synthesis and Extraction of Lanthanofullerenes and Its DEIMS, ESR Characterizations
    LIU Bhg-Bhg, XU Wen-Guo, LIU Zi-Yang, YANG Hai-Bin, LI Ming-Hui, LIU Shu-Ying, ZOU Guang-Tian
    1996, 17(5):  690-692. 
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    The synthesis for lanthanofullerenes was studied by activating the La2Oa containing graphite rod in situ and back-burning the carbide-rich cathode deposite, La@C2n are efficiently extracted in high temperature toluene, among them, La@C74 as a new species is added into the soluble lanthanofullerenes, The toluene extraction is first characterized by desorption electron impact(DEI)mass spectrometry, The ESRspectrum of the extraction at room temperature is also discussed.
    Adsorptive Voltammetric Determination of Mixed Pigment by Iterative Target Transformation Factor Analysis
    BAI Jie-Ling, NI Yong-Nian
    1996, 17(5):  693-697. 
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    Synthetic pigments,such as amaranth,sunset yellow,tartrazine and ponceau 4R,have sensitive adsorptive voltammograms in a phosphate buffer(pH=5.7).The voltammetric waves of these pigments,however,are seriously overlapped and it is difficult to determine them without a preseparation,In this paper,the experimental conditions were investigated.The mixture was accumulated for 240 s at a HMDEwith a accumulate potential,-100 mV.After a 10 s quiet time the potential was then scanned from -100 to -100 mVusing linear sweep voltammetry(LSV) with a scan rate,100 mV/s.The voltammetric data of mixed pigments were processed by a chemometric approach,iterative target transformation factor analysis(ITTFA)and acceptable results with a total prediction error,8.35%,were obtained.
    The Prediction of Cation Exchange Distribution Coefficients with Artificial Neural Network
    LIU Man-Cang, ZHANG Hai-Xia, ZHANG Rui-Sheng, ZHANG Li-Hua, HU Zhi-De
    1996, 17(5):  698-701. 
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    The ion exchange distribution coefficients of cat ions having characteristie valence in main groups were predicted by using extented delta-bar-delta neural networks, The effect of structure of network, the learning Epochs and the size of learning set on predicted results was investigated.The suitable conditions are;input nodes 4; output node; 1; the learning epochs; 3000; the size of learning set;112.The RMS(root-mean-square error) is smaller than 7%under the suitable conditios.
    Studies on Uric Acid Microbiosensoe
    LIU Bao-Hong, DENG Jia-Qi
    1996, 17(5):  702-706. 
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    An electrode for the determination of uric acid was prepared.It employed a kind of bacillus as the biocatalyst and an oxygen gas electrode as the basic electrode, The effect of the culture medium, the response character of the electrode and its kinetic mechanism are studied.At suitable pH, the uric acid concentration is linear in the range of 1.0×10-5～4.0 ×10-4mol/L, the apparent Michaelis constant Km is 2.8×10-4 mol/L, the activation energy is 47000J/mol, and the temperature coefficient is 1.8.
    Studies on Vertical Amperometric Detector for Capillary Electrophoresis
    XU Dan-Ke, HUA Lin, CHEN Hong-Yuan, ZHU Shu-Tao
    1996, 17(5):  707-709. 
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    Avertical electrochemical detection for capillary electrophoresis was described.The detector consisted of the home-constructed micromanipulator and the electrochemical cell.The performance was evaluated by the determinations of dopamine, norepinephrine and epinephrine in the CEECsystem.The lowest detectable concentration was 1.0×10-7 mol/Land the relative standard deviation was less than 5% for each of the compounds.
    Computerized Amperometric Detection for capillary Electrophoresis
    HU Sben, LI Pei-Biao, CHENG Jie-Ke
    1996, 17(5):  710-712. 
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    Acomputerized end-column amperometric detector for capillary zone electrophoresis is constructed.The microelectrode is positioned at the end of 25 μm i.d.capillary by micromanipulator directly.The electrode potential is controlled and the signal is sampled by the microcomputer.Application of the system to the separation and detection of NE, IPand CATis demonstrated.This system is also applied to investigate the field-amplified injection in capillary electrophoresis with amperometric detection and the concentration limits of 0.45～0.65nmol/L for DA, NE, Eand IPare achieved.
    The Chromatographic Behaviour of Arylthioacetates and Their Oxidation Products (Ⅲ) ──In Reversed-Phase High Performance Liquid Chromatography
    LIAN Hong-Zhen, MAO Li, MIAO Jin, XU Xiao-Qing, ZHANG Zheng
    1996, 17(5):  713-715. 
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    The reversed-phase high performance liquid chromatographic behaviour of arylthioacetates and their oxidation products has been studied by using ODSas stationary phase and methanol-water as mobile phase.The relationship between the retention characteristics and the molecular structure of these compounds was investigated.Results showed that;(1)The k'values increase with the increase of alkyl chain length(k'-CH(CH3)2>k'-CH3);(2)The k'values decrease with the number of oxygen in polar functional groups increasing(k'-S->k'-SO->k'-SO2-);(3)the k'values increase evidently when chlorine exists in benzene ring; (4)The effect of nitro-group in benzene ring on k'values is dependent upon the number and substituting position of polar groups.
    Stufies on the Simltaneous Determination of Trace Polycyclic Aromatic Hydrocarbons by Synchronous Microemulsion-stabilized Room Temperature Phosphorimetry
    YANG Xin, DONG Chuan, WEI Yan-Sheng, JIN Wei-Jun, LIU Chang-Song
    1996, 17(5):  716-718. 
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    In this paper,a new method of synchronous microemulsion stablized room temperature phosphorimetry for the simultaneous determination of fluoranthene and chrysene, fluoranthene and acenaphthene, fluoranthene and p-terphenyl is described.The experiments indicate that suitable △λare 188 nm, 185 nm and 191 nm in proper order.Synchronous peaks are situated at 360 nm and 323 nm(fluoranthene and chrysene), 360 nm and 306 nm(fluoranthene and acenaphthene), 360 nm and 307 nm(fluoranthene and p-terpheny1)respectively in the mixture.The limit quantity of interference between components in binary mixture was examined.The linear range of determination reached two amount order and relative standard deviation less than 5%.The results of determination for double components synthetic sample are satisfactory.
    The Application of Micellar Media in Differential Rate Kinetics Analysis──Simultaneous Determination or Cobalt and Nickel
    LIU He-Chun, CAI Ru-Xiu, HUANG Hou-Ping
    1996, 17(5):  719-721. 
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    Micellar Media in differential rate kinetics analysis has been applied to simultaneous determination of cobalt and nickel.This method was based on the formation of ternary complex of them with 4-(2-pyridylazo)resorcinol(PAR)and cetyltrimethylammonium bromide(CTMAB).The rate of the formation of ternary complex of Co(Ⅱ) was very fast, but that of Ni(Ⅱ) was relatively slow.The relative deviation for determinations of two components was within 8%.The logarithmic extrapolation method with microcomputer 386 has been applied to the determination of Co(Ⅱ) and Ni(Ⅱ)in synthetic samples with satisfactory results.
    Reaction of Tricarbonylcyclopentadienyl Molybdenum Anion with 1,3-Dihalopropane
    JIN Ren-Zhi, XU Shan-Sheng, ZHOU Xiu-Zhong, WANG Ru-Ji, WANG Hong-Gen
    1996, 17(5):  722-726. 
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    Reaction of tricarbonylcyclopentadienyl molybdenum anion with X(CH2)3X(X=Br,I)in diglyme gave the cyclic carbene of molybdenum complex──CpMoX(CO)2·CO(CH2)2CCH2.The similar reaction of sila-bridged biscyclopentadienyltricarbonyl molybdenum anion with 1,3-dihalopropane proceeds smoothiy to afford the corresponding sila-bridged bis[cyclic carbene molybdenum]complex,E[C5H4MoX(CO)2·CO(CH2)2CH2]2(E=Me2Si,Me2SiSiMe2, Me2SiOSiMe2).The crystal structure of One(X=I) of the latter complexes was determined by X-ray crystallography.The crystal is triclinic, space group P1 with α=0.8188(1) nm,b=1.0454(3) nm,c=2.3325(4) nm,α=94.14(2)°,β=94.07(1)°,γ=102.48(2)°,V=1.9306 nm3,Z=2,Dc=1.854 g/cm3。
    Studies on the Acylation and condensation of 4-Aminodiphenylselenide
    MA Huai-Rang, CHENG Xiao-Fei, ZHANG Bing-Lin, YANG Bing-Qin, CHEN Jing-Yuan
    1996, 17(5):  727-730. 
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    Eighteen kinds of organoselenium compounds with biological activities have been synthesized by the acylation and condensation of 4-aminodiphenylselenide with organic anhydrides and aromatic aldehydes.All products are characterized by elemental analysis, IR, and 1H NMRspectra.It is found that 4-aminodiphenylselenide is similar to the aromatic primary amines in both reactions.
    Acid-catalyzed Reductions of N-Arylfluorenimines by NAD(P)H Models
    LU Yun, CHENG Jin-Pei, WANG Hong-Xing, XIA Chi-Zhong
    1996, 17(5):  731-734. 
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    Acid-catalyzed reductions of five N-arylfluorenimines by the NAD(P)Hmodels(Hantzsch ester and BNAH)are reported.The experimental results indicate that imine structure,acid strength, and solvent are the main factors affecting the overall yield of the reaction.Mechanism of the acid-catalyzed hydride transfer reactions are discussed.
    Studies on the Immobilization of glucose Isomerase and the Properties of the Immobilized Glucose Isomerase
    GE Yu-Bin, WANG Li-Ping, KONG Wei, ZHOU Hui, LI Wei, SHEN Jia-Cong
    1996, 17(5):  735-738. 
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    In this paper we successfully immobilized bilayer glucose isomerase in porous ptrimethylamine-polystyrene(TMPS)beads by use of a new method of immobilization of enzyme──molecular-deposition.The effects of immobilizing time,the concentration of nature enzyme, the concentration of hexamethylene bis(trimethylammonium bromide), the concentration BCDwere investigated.The properties of this immobilized enzyme were also studied.The results obtained show that the activity and the protein loading of per weight bilayer immobilized enzyme are doubled as compared to monolayer immobilized enzyme.The activity of immobilized bilayer glucose isomerase is 1200 IU/g wet gel.
    Studies on Nonlinear Kinetics for Thiourea Oxidation──H2O2-SC(NH2)2-CU2+)Reaction System
    LIN Juan-Juan, GAO Qing-Yu, MA Ke-Qin, WANG Yue-Min, ZHAO Xue-Zhuang
    1996, 17(5):  739-742. 
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    The reaction between hydrogen peroxide and thiourea in acidic medium(HCLO4) catalyzed by Cu2+) has been studied both in a closed(batch) system and in a flow reactor (CSTR).Anew thiourea oscillator has been found.Under the batch condition the reaction displays single-peak oscillation behavior in the redox potential.Amplitude and induction time of the reaction vary as the initial reactant concentrations and the temperature of reaction.This induction time could be reduced by higher initial hydrogen peroxide concentrations and lower initial thiourea concentrations.In the CSTR, the reaction system displays sustained periodic oscillations in the potentials of Pt electrode and Cu2+)-selective electrode and pHelectrode, As the flow rate is decreased, complex oscillations appear.The oscillatory region is shown in phase diagrams.The oscillation behavior is related to[H2O2]/[SC(NH2)2]ratio.No bistability is observed in the system.
    Total Synthesis of (±)Caulilide(Ⅰ)
    SU Jing-Yu, LIU Hong-Xia, ZENG Long-Mei
    1996, 17(5):  743-746. 
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    The total synthesis of(±)caulilide(1) which shows a potent cytotoxicity is described.Cyclocitral(2) was prepared from citral via citralylimine in 85%～90% yield.The reaction of 2 with KCNfollowed by dehydration afforded nitrile 3 in 56% yield.Allyl oxidation of 3 was performed by using pyridium dichromate-t-butyl-hydroperoxide to give ketonitrile(4) which was a mixture of geometrie isomers of 4a(cis) and 4b(trans).After separation on a silica gel column, the cis isomer 4a was then hydrolyzed and simultaneously lactonized in conc.HCl solution to form a lactone(±)-5.The synthesis of caulilide(1) was completed by the reduction of 5 with NaBH4. The crude product was separated by high performed chromatography to give the target compound (±)-1.
    Solid Phase Peptide Synthesis of Designed Yeast Transcriptional Activator Ac [Q236,Q242]GCN4(226─252)─GGC─NH2 and Its Dimerization
    ZHANG Ruo-Heng, WANG He, XU Xiao-Jie, TANG You-Qi
    1996, 17(5):  747-749. 
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    Yeast transcriptional activator GCN4(226-252)-GGC-NH2 and the designed Ac-[Q236,Q242)]GCN4(226-252)-GGC-NH2 aiming at altering GCN4 DNA-binding specificity was prepared by stepwise solid phase peptide synthesis.It was found that the yield of the peptide would be greatly improved when treated with dithiothreitol(DTT).The dimer was obtained by air oxidation, which would be used in the sequence-specific DNAbinding activity experiments.
    The Syntheses of N,N'-Bis(aroylmethyl)-1,10-diaza-4,7,13,16-tetraoxacyclooctadecane
    YU Jiang, XU Zhen-Hua, XU Guang-Xian
    1996, 17(5):  750-752. 
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    Two new kinds of organic macrocycle compounds were synthesized with different methods;N,N'-bis( a- phenacyl)-1,10-diaza-4,7,13,16-tetraoxacyclooctadecane(Ⅱ) and N,N'-bis(ω-acetothienone)-1,10-diaza-4,7, 13,16-tetraoxacyclooctadecane(Ⅱ).The fluorescent characteristics of compound Ⅱis better than that of traditional fluorescent ligand of a-thenoyltrifluoroacetone( HTTA).The probable reaction process in our work is also discussed.
    A New System of Titanium(Ⅳ)──Titanates of α-Keto Carboxylic Acids with Li Reagents
    DUAN Xin-Fang, YIN Cheng-Lie
    1996, 17(5):  753-755. 
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    The new reductive reaction in the system of titanates of α-keto carboxylic acids and Li reagents has been further investigated.Aseries of alcohols and phenols was introduced to examine the change of the ratios of additions.It is concluded that phenols increase the ratios of additions remarkably.
    Theoretical Studies on the Structure and Vibrational Spectrum of B8N12Cage
    YANG Cheng, FENG Ji-Kang, GE Mao-Fa, SUN Chia-Chung
    1996, 17(5):  756-759. 
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    The geometry,electronic structure and vibrational spectrum of B8N12 cluster were studied by using quantum chemical ab initio method,and its stability and properties were discussed.
    A Proof for N2-binding Inside M-cluster Cage of Nitrogenase
    HUANG Jing-Wei, CHEN Can-He, ZHANG Feng-Zhang, LIN Zhong-Yu, ZHANG Hong-Tu, WAN Hui-Lin
    1996, 17(5):  760-763. 
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    The experiments that the reductive deuteration and products-selectivity of C2H2 are affected by N2 in D2O-nitgrogenase have been done.It is found that the C2H2 reductive activities decreased ca.80.7% and 89.3%,respectively,with mixtures of C2H2and N2 in the ratios of 1;108.3 and 1;216.7(volume ratio),as compared with ca.42.6% and 74.2% observed with C2H2 in argon(1;65 and 1;108.3,volume ratio) in the absence of N2;ca.3.19% and 4.95% trans-2-didutero ethene were observed form FTIRspectra of the ethenes-1,2-d2 obtained, respectively,with mixtures of C2H2 and N2 in the ratios of1;108.3 and 1;216.7(volume ratio).The results give a strong proof for the conclusion in which N2 binds inside the cage of M-cluster.
    A Study of Athermal Action of Electromagnetic Waves on Chemical Reaction
    HUANG Ka-Ma, LIU Yong-Qing, TANG Jing-Xian, ZHAO Jun, WANG Bao-Yi
    1996, 17(5):  764-768. 
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    The acceleration of chemical reaction with the radiation of microwave is caused by not only the dielectric heating,but also the athermal action.Here the experimental results indicate that Lorentz force of electromagnetic waves on ions and polar molecules can cause the variation of activation energy and pre-exponential factor,the influence of electromagnetic waves on chemical reaction may be described by using the eiectromagnetic action factor.
    Correlation of Coupling Constants JCH and Bond Angles in Ringed Organic Molecules
    ZHAO Cun-Yuan, XIAO Tai, XU Xian-Fang, YOU Xiao-Zeng
    1996, 17(5):  769-772. 
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    The linear relationship between one bond carbon-hydrogen spin-spin coupling constants JCHand the sum of internuclear angle distortions ∑△θ or that of real bond angle dissortion∑△βhas been found.Quadratic expressions of JCH vs.θCCC and JCH vs.s%(C—H) are obtained by fitting polynomials to experimental coupling constants JCH andθCCC or s%(C—H) bonds for the type R2CH2.All the proposed formulae give JCHvalues with less than 2.0 Hz average deviations from experimental values.
    The Jahn-Teller Distortion of C60+ Radical
    TENG Qi-Wen, WU Shi, SHANG Zhen-Feng, FENG Ji-Kang
    1996, 17(5):  773-776. 
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    C60+radical has been optimized by using INDOmethod and the D5d geometry for C60+ was obtained.It is shown that the Jahn-Teller distortion took place in C60+indeed,which led to the lengthening of the C60sphere of original Ih symmetry along the C5 axis.There are 7 kinds of bonds and 4 types of atoms in C60+(D5d),and the single bonds were shortened whereas the double bonds were lengthened,i.e.,the bond lengths tend to an average.Because the positive charge and unpaired electron are mainly distributed near the equator of C60,the carbon atoms located close to the equator possess a higher reactivity.
    A Theoretical Study of the Decompositions of CF3CO and CF3C(O)O Radicals
    MA Ao, SUN Li-Peng, WANG Yi-Xuan, LIU Cheng-Bu, DENG Cong-Hao
    1996, 17(5):  777-780. 
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    Ozone in the stratosphere is important to the life of human being and the radicals CF3CO and CF3C(O)O may play iniportant roles in the removal of ozone by participating in the circular catalytic reactions of the degradation of ozone.So it is essential to make clear the thermodynamic and kinetic properties of the decomposition reactions of the two radicals.Several experimental results had been reported on these reactions,but these results are quite different from each other.Theoretically,these reactions liad been studied by using ab initio method at 6-31G* level and the correlation energy was considered with PMP2. In this paper,the thermodynamic and kinetic data of the reactions had been calculated over the temperature interval from 100 Kto 1500 Kbased on statistical thermodynamics and transition state theory by using the data obtained from ab initio calculation.The thermodynamic and kinetic data of these reactions such as Kp and kr had been obtained.The result of calculation is well consistent with the latest experimental data and the conclusion was drawn that both CF3COand CF3(O)Oradicals are too unstable to participate in the catalytic cycles of the removal of ozone in the stratosphere.
    Molecular Electronegativity in Density Functional Theory(Ⅳ)──Direct Calculations or Charges Distribution and Total Energy in a Macrocvclic Molecule
    WANG Lu-Hong, SHEN Er-Zhong, YANG Zhong-Zhi
    1996, 17(5):  781-785. 
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    On the basis of electronegativity expressed in density functional theory and electronegativity equalization principle,the Modified Electronegativity Method(MEEM) has been developed,which allows the direct computations of the atomic charges and total energies in various molecules.As application,the three macrocyclic molecules 18-crown-6,24-crown-8 and 24-cryptand are calculated and quite good results of atomic charges and total energies are obtained as compared with those from the ab initio STO-3G SCFcalculations.
    Electro-catalytic Effect of meso-Tetra(4-sulfophenyl)·porphyrin on Voltammetric Behavior of Some Eu(Ⅲ)Carboxylic Acid Complexes in Aqueous Solution
    QIAO Qing-Dong, GAO Xiao-Xia
    1996, 17(5):  786-789. 
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    It is difficult to synthesize the complexes of rare earth ions with meso-tetra(4-sulfophenyl)porphyrin(TPPS)in aqueous solution.Eu(Ⅲ)can form complexes with carboxylic acids, such as acetic,tartaric, malonic, gluconic, citric acids and EDTAwith different stability constants,and exhibits irreversible or quasi-reversible redox peaks in cyclic voltammograms.TPPS, which adsorbed on Hg electrode,exerts catalytic effect on the redox behvior of Eu(Ⅲ)-acetic, tartaric, malonic acid complexes by changing the irreversible process to a reversible one, but the Eu(Ⅲ)-TPPScomplex was not formed.The mechanism of such a catalytic effect has been discussed.
    Studies on the Adsorption Property of No on the Ni-based MixedOxide Catalysts with Perovskite-like(ABO3 and A2BO4)Structure
    ZHAO Zhen, YANG Xiang-Guang, WANG Xue-Zhong, WU Yue
    1996, 17(5):  790-793. 
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    The mixed oxides LaNiO3, La0.1Sr0.9NiO3, La2NiO4 and LaSrNiO4 with perovskite(ABO3)and related(A2BO4)structures were prepared and the adsorption property for NO and the catalytic activity for NO decomposition over these oxidse were also tested.The catalysts were characterized by means of BET surface measurement,chemical analysis, NO-TPDetc..It was shown that the adsorption amount of NO is correlated with the concentration of oxygen vacancy formed and the adsorption type and strength of NOare related to the valence of metallic ion.Generally there are three kinds of adsorption species, NO-,NO+ and NO on the mixed oxides, among them the negative adsorpion species(NO-)are active for NOdecomposition.The weaker the adsorption of oxygen on the catalyst is, the faster the mobility of oxygen is and the easier the redox process takes place in reproducing the active sites in which the oxygen species(O-,O2-)would participate.
    Oxygen Reduction on the Glassy Carbon Electrodes Modified with Two Film of Polymer and Cobaltphthalocyanine
    DONG Guo-Xiao, LI Ji-Sheng, ZHUANG Rui-Fang
    1996, 17(5):  794-796. 
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    Phthalocyanine-2,9,16,23-tetracarboxylic acid cobalt complex(1)and phthalocyanine-2,9, 16, 23-tetracarboxyl tetrachloride cobalt complex(2) were synthesized.The glassy carbon electrodes coated with polyethylpyridine film or polyaniline film were made by electrochemical methods.Chemically modified electrodes(CMEs)were prepared by precipitation of 1 from its solution to the electrode coated with the polyethylpyridine film or electrode coated with the polyaniline film, and by precipitation of 2 from its solution to the electrode coated with polyaniline film.Catalytic activities and lifetime of these CMEs were investigated to electroreduction dioxygen in aqueous solution with cyclic voItammogram.ElectrodeⅠcoated with 1 and polyethylpyridine showed activity in 0.2 mol/Lpotassiumchloride aqueous solution.ElectrodeⅡcoated with 1 and polyaniline was the same active as electrode Ⅲ coated with 2 and polyaniline in 1.0 mol/Lhydrogen sulfate aqueous solution which was active during a long continuous operation.Ⅲ had a longer life thanⅠand Ⅱ.
    Studies on the Storage Stability of SO42-/ZrO2 Solid Superacid
    CHEN Jian-Min, MIAO Chang-Xi, HUA Wei-Ming, GAO Zi
    1996, 17(5):  797-799. 
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    The storage stability of SO42-/ZrO2 solid superacid in different environments was studied.The samples kept in moist atomosphere lost their superacidity and catalytic activity for butane isomerization within 30 days.The results of TGand IRspectroscopy show that reheating the moistened samples results in a decrease in surface sulfur content,leading to the deterioration of the superacid.The ways to avoid such a disadvantage were suggested.
    Time-Resolved Small Angle Laser Light Scattering Apparatus
    ZHANG Jian-Wen, YAN Dong, ZHOU Hong-Wei, YANG Yu-Liang
    1996, 17(5):  800-804. 
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    In this paper,a time-resolved small angle laser light scattering(SALS)apparatus has been described.In this apparatus,a two-dimensional CCDcamera has been used as a detector, then the intensity of the scattered light is converted to the digital signals and stored in the computer or in a video recorder for further data analysis.As a demonstration, the SALSpattern of polypropylene spherulite has been recorded and the data are presented in ways of grayed picture,three-demensional stack plot and contour plot.To show the feasibility of studying the dynamics of phase separation,the time evolution of light scattering during the cure-induced spinodial deconposition of an epoxy composite has been recorded.
    On the Melting of the Nascent State Nylon 1010 with Different Molecular Weights
    ZHU Cheng-Shen, CHEN Y, YANG Gui-Ping, WANG You-Wen, WANG Jing-Wu, MO Zhi-Shen
    1996, 17(5):  805-807. 
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    The melting of the nascent state nylon 1010 samples melt condensation polymerized with different Mη have been studied by DSC.The relations of melting point, content of higher order crystal with Mη are similar,the plots like a peak, at Mη=1.48×104 have the maximum.The melting heat, melting entropy and crystallinity are decreased gradually with Mη increasing.
    Syntheses and Optical Properties of Alkoxylneodymium-Containing Copolymers
    WANG Liao-Hui, ZHANG Wen-Gong
    1996, 17(5):  808-811. 
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    For increasing in the transmittancy of rare earth metal-containing polymer,ten alkoxylneodymium-containing monomers, which have good compatibility with MMA,are synthesized by the reactions of neodymium alkoxides with maleic anhydride.Then ten alkoxylneodymium-containing copolymers are prepared by the copolymerizatons of these monomers with MMAusing AIBNas an initiator.Studies on optical properties of these copolymers indicate that, in comparison with PMMA, alkoxylneodymium-containing copolymers have higher transmittancy and refractive indexes,and their refractive indexes increase linearly with increasing Nd content.Moreover, they have Nd3+) ion characteristic light selective absorbability.So they may be a series of new type optical plastics.
    Correspondence Rule Between the Curing Theories with Cyclization ann without Cyclization
    HUANG Xu-Ri, XIAO Xing-Cai, LI Ze-Sheng, SUN Chia-Chung, TANG Au-Chin
    1996, 17(5):  812-814. 
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    By means of the sol fraction of the Aa1…Aai…Bb1…Bbi-type polymerization in which the cyclization is involved, the equilibrium number fraction distribution is obtained by using Lagrange's expansion techniques.Furthermore, a correspondence rule between the curing theories with cyclization and without cyclization is proposed.Using this rule various results of the curing theory with cyclization can be obtained directly from the corresponding ones of the curing theory without cyclization.
    The Study on a Novel Anticoagulative Material
    YING Xi-Zhang, WANG Bei-Bei, YAO Shi-Kai, ZHU Jian-Guo, ZHU Li-Hong, SHAO Hui-Zhen, MA Ting, YAO Hong-Xi
    1996, 17(5):  815-819. 
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    The heparin has been grafted directly on the surface of polyurethane with the help of hypothermia plasma treatment.The smooth polyurethane-heparin graft copolymer is deeped in the inside tube wall.By dotting time (CT)test fresh human blood is injected to the polyurethane-heparin graft tube,after 5 days and nights there isn' t any thrombin the inside tube wall.By kaolin partial thomboplastin time (KPTT), prothrombin time(PT)and thrombin time (TT)tests to these polyurethane-heparin graft tubes, the results are that,this novel graft tube has anticoagulation visibly and there isn't falling free heparin from the tube wall, In infrared spectrum peaks 1165 cm-1 and 1339 cm-1 are symmetric and antisymmetric stretch vibrations of SO2 group in new covalent bond N—SO2 or O-SO2.
    The Solution Properties of Phenolphthalein Poly (arylether sulfone)(Ⅰ) ──The Solubility Behavior and Determination of M-H Equations
    BO Shu-Qin, YANG Guo-Jun, PAN Hai-Yan, HU Hui-Zhen, CHEN Tian-Lu
    1996, 17(5):  820-823. 
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    Aseries of narrow molecular weight distribution fractions of phenolphthalein polyarylether sulfone(PES-C)had been prepared.The Mw of these fractions were determined by conventional light scattering method.The[η]and the Huggins slope constant k' in DMF, CHCl3 and 1,2-dichloroethane were also determined.The Huggins constants are greater than 0.5 in all of these solvents showing a special solubility behvior .The Mark-Houwink equations of PES-Cin these solvents at 25℃ are [η]=2.79× 10-2Mw0.615(DMF);[η]=3.96× 10-2Mw0.58(CHCl3); [η]=7.40× 10-2Mw0.52(CH2ClCH2Cl).
    Polycondensation Reaction of p-Acetoxybenzoic Acid and Poly(ethylene terephthalate) and the Formation of Ether Bonds
    LI Yong, WANG Kuan, ZHANG Guang-Li, ZHANG Hong-Zhi
    1996, 17(5):  824-828. 
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    The transesterification reaction of acetates and etherification reaction during the polycondensation reaction of p-acetoxybenzoic acid (Ac-PHB)and poly(ethylene terephthalate)were studied by analyzing the reaction mixture sampled after different reaction time by 1H NMRspectra and [η] determination.Just in the beginning of the polycondensation reaction the PETchains degraded vigorously with the formation of acetoxy ethylene end groups of about 25% (molar ratio)of total ethylene content.Both the acetoxy ethylene and acetoxy phenylene end groups were reactive toward the polycondensation reaction.Using PETof low molecular weight or bis-hydroxyethylene terephthalate as the original material, the copolyester of high molecular weight could be prepared.However, it's Tf and HDTwere lower, and the solubility was higher than those as PETof high molecular weight was used.These poor properties of copolyester were explained by the high content of ethylene groups and the formation of ether bonds, among which the semi-aromatic ether content is much higher than the aliphatic one.Both the two ether bonds could react with carboxy end groups to propagate the chains under vacuum reaction condition .
    Investigation of Fibroin Composition of Bombyx Mori Silk Proteins by SDS-PAGE
    YU Tong-Yin, CAI Zai-Sheng, HUANG Wei-Da
    1996, 17(5):  829-831. 
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    The fibroin proteins directly extracted from silk glands of Bombyx mori were used for polyacrylamide gel electrophoresis in th presence of sodium dodecyl sulfate (SDS-PAGE).The subunit structure of fibroin molecule was discussed.It has been elucidated that the native fibroin molecule consists of subunits a,b and c with molecular weights of 280 kD, 230 kD and 25 kD, respectively, Since the amount of them is much more than that of the b subunit, the a and b subunits are the major component of fibroin.Of which the b subunit is composed of smaller e subunit of Mw about 130 kDand f subunit of MW about 125 kD,linked by disulfide bonds.
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