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    24 November 1996, Volume 17 Issue 11
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    Articles
    Studies on the Stability and Structure of High Tc Y-Ba-Cu-O Superconductor with F Element
    ZHONG Shan, YU Yong-Qin, CHEN Long-Wu
    1996, 17(11):  1661-1665. 
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    The samples of high Tc Y-Ba-Cu-Osuperconductor with Felement were prepared by using BaF2,CuF2,YF3 instead of BaO,CuO,Y2O3 respectively.The substitutive ratio was about 45%. The zero-resistance temperature was 82.5～93.5K.By means of X-ray powder diffraction,infrared spectroscopy,difference thermal analysis,the structure and stability of the samples were investigated.The preliminary results show that only small amount of Felement entered the superconductive phase,and made the stability of the high Tc Y-Ba-Cu-Osuperconductor with Felement increasing greatly in the environment of water vapor and carbon dioxide.
    Hydrothermal Synthesis and Characterization of BaZrO3 Based Solid Electrolytes
    ZHENG Wen-Jun, MENG Xian-Ping, ZHOU Feng-Qi, LIU Chuan, YUE Yong, PANG Wen-Qin
    1996, 17(11):  1666-1669. 
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    Based on hydrothermal synthesis of BaZrO3,a series of solid electrolytes were prepared.The phase,grain size and dopant-containing ratios of the products were characterized by the techniques such as XRD,SEM,IR,27Al MAS NMR and chemical analysis.The results indicated that the phase is cubic perovskite-type BaZrO3,the products show polycrystalline powders in which grain sizes are 3～5μm.Moreover,under the hydrothermal conditions in this paper,the dopant-containing ratios of the products are similar to that of starting feedings.
    Studies on Phase Chemistry of Synthesizing Mechanism for Compound Cs3Dy2Br9
    WANG Hui, RAN Xin-Quan, CHEN Pei-Heng
    1996, 17(11):  1670-1672. 
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    Phase chemical relation of quaternary system CsBr-DyBr3-HBr(13%)-H2O at 25℃ for CsBr and DyBr3 reaction in HBr was studied for the first time,a new kind of compound 5CsBr·3DyBr3·24H2O was found in the system.X-ray powder diffraction, thermal analysis(TG and DTA) and polarization-character of new compound obtained from the system were investigated.Meanwhile,the synthetic mechanism of compound Cs3DY2Br9 was suggested here on the basis of phase chemical relation of the system.
    Site-directed Mutagenesis at Glu44 and Clu56 of Cytochrome b5 and Their Structural Comparison with Wild Type Protein
    SUN Yu-Long, WANG Yun-Hua, ZHOU Gang, HUANG Zhong-Xian, XIE Yi, WU Xiao-Zhou
    1996, 17(11):  1673-1677. 
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    The codon of Glu44 and Glu56,GAAin the gene of trypsin-solubilized bovine liver microsomal cytochrome b5(82 residues in length)was changed into GCTcoding for Ala by oligonucleotide site-directed mutagenesis and three cytochrome b5 mutants of E44A,E56A,and E44/56 Awere obtained.The mutant genes were ligated into ECORⅠ/Hind Ⅲ-cut pUC19 and the resulting plasmid was transformed into JM83.All of them were expressed in E. coli successfully.The bacteria containing wild type or mutant cytochrome b5 were dealt with lysozyme, deoxyribonuclease and ribonuclease,then the proteins were isolated and purified by ammonium sulfate precipitation,ion-exchange chromatography and gel filtration.The UV-visible and circular dichroism spectra of purified proteins were studied. The results show that the mutagenesis at the surface residues does not alter the structure of cytochrome b5 significantly.
    Synthesis and Crystal Structure of Erbium Nitrate Complex with 6,6'-Bis(diphenylphosphine oxide methyl)-2,2'-bipyridine-1,1'-dioxide
    FENG Yin-Chang, TANG Yu, TANG Ning, GAN Xin-Min, TAN Min-Yu, YU Kai-Bei
    1996, 17(11):  1678-1681. 
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    The erbium nitrate complex with 6,6'-bis(diphenylphosphine oxide methyl)-2,2'-bipyridine-1,1'-dioxide was synthesized and characterized by IRspectra and molar conductance.The crystal and molecular structures of the complex were determined by single crystal X-ray diffraction technique with a four circle diffractometer to give final R and Rw values of 0.0541 and 0.0490.The crystal of the complex is monoclinic with a space group C2/c.The unit cell parameters are:α=1.9830(4)nm,b=2.3135(4)nm,c=1. 8600(3)nm;β=96.18(2)°,z=4,V=8.484(3)nm3,Dc=1.33g/cm3. The Er3+ ion is chelated by four P=Oand four N-O groups from the two organic ligands. All the coordinated water molecules are replaced by the organic ligands.
    Hydrothermal Synthesis and Ionic Conductivity of a New Sodium Zincosilicate Na1.0Zn1.62Si1.38O4.84·0.6H2O
    CUI De-Liang, FU Ge-Yan, PANG Guang-Sheng, XU Xiu-Ting, FENG Shou-Hua, XU Ru-Ren
    1996, 17(11):  1682-1684. 
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    Anew sodium zincosilicate single crystal Na1.0Zn1.62Si1.38O4.84·0.6H2O with size of 0.3mm×0.3mm×0.3 mm was prepared by hydrothermal synthesis method. Powder X-ray diffraction analysis result shows that this compound is a new phase.The compound is stable up to 500℃. The results of ACimpedance measurement shows that its ionic conductivity at 450℃ is 2×10-4S·cm-1 and the activation energy for ionic conduction is 79.64 KJ/mol.
    Perparation and Structure of Nanocrysalline BaTiO3
    FANG You-Ling, ZHAO Wen-Kuan, ZOU Hua-Min, WANG Ren-Hui
    1996, 17(11):  1685-1686. 
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    Nanocrystalline BaTiO3 with diameter of particles less than 30 nm was prepared by the pyrolysis of peroxide.The composition of the peroxide precursor was determined, and the condition of preparing nanocrystalline by the pyrolysis of peroxide was identified,the crystalline structure,defect and domain structure were studied by XRDand TEM methods.
    Interaction of Bovine Serum Albumin with Methyl Orange in Acidic Solution
    WEI Yong-Ju, LI Ke-An, TONG Shen-Yang
    1996, 17(11):  1687-1692. 
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    The interaction of methyl orange(MO) with bovine serum albumin(BSA)in acidic solution was investigated by a spectrophotometric method. It was considered that the combination of BSAwith MO is due to the noncovalent binding forces.The color change during the binding process is because of the transformation of MO from free-acidic form into bound-basic form.The relationship between absorbance and concentrations of MO species was studied.The Scatchard model was discussed in a new point of view.Two conditional constants,apparent binding constant and maximum binding number,were proposed to express the binding ability of MO on BSA,and two linear regression equations were derived to estimate these two parameters.It was found that sodium chloride concentration and acidity have significant effect on the binding reaction.
    Chemiluminescence Determination of Brucine,Strychnine and Ephedrines Based on HPLC Separation
    ZHU Long, FENG Man-Liang, WAN Xiu-Qin, LU Jiu-Ru
    1996, 17(11):  1693-1696. 
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    In this paper,the chemiluminescence reaction of brucine,strychnine and ephedrines in KMnO4-H+-reductant system has been characterized with respect to their ability to act as a rapid and sensitive chemiluminescence determination system of the above alkaloids.This method has been connected with HPLC which fitted with a C18 column for separation so as to determine these alkaloids in sample.The detection limits are 1.0×10-10g/mLof brucine,1.0×10-8g/mL of strychnine and 1.0×10-5 g/mLof ephedrines, respectively.The relative standard deviation is less than 3% and recovery is 94%～101%.Since the dissolved oxygen did not affect the determination,this method provide advantages of wider linear range,high sensitivity and easy to operate.
    The Theory and Experimental Verification of Double Potential Step Chronoamperometry and Chronocoulometry at Microring Electrodes
    WU Zhi-Bin, ZHANG Zu-Xun
    1996, 17(11):  1697-1701. 
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    In this paper,analytical expressions for double step potential chronoamperometry and chronocoulometry with simple reversible electrode reaction at microring electrodes are derived.In order to examine the validity of the theory,experiments were carried out on gold microring electrodes with K4Fe(CN)6 in 0.5 mol/L KCl solution.The experimental results are in good agreement with the theoretical ones.
    Studies on Screening Immune Drugs by Linear Sweep Polarography
    KANG Xiao-Feng, SONG Jun-Feng, HU Yin-Hua
    1996, 17(11):  1702-1705. 
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    The hemolytic activity of hemolysin was investigated by linear sweep polarography in this paper.Asensitive polarographic reduction wave of hemolysin was observed in 1/15 mol/L Na2HPO4～1/15 mol/L KH2PO4 buffer solution(pH=7.4).The peak potential was -1.82 V(vs.SCE).The peak height was linearly proportional to its biological activity in the ranges of 6.0×10-6～5.3×10-5 unit/mL and 5.3×10-5～2.0×10-3 unit/mL.According to the various effects of drugs on the formation of hemolysin antibody,a new method for screening immune drugs was established.This method is simple,rapid,and the assay of hemolysin activity is no longer dependent upon immune hemolysis process.The results are accurate and reliable.
    Determination of DNA by Use of in situ Photochemical Fluorescence Probe──Sodium 9,10-Anthraquinone-2-sulfonate as a Photochemical Fluorescence Probe
    LI Wen-You, XU Jin-Gou, GUO Xiang-Qun, ZHU Qing-Zhi, ZHAO Yi-Bing
    1996, 17(11):  1706-1707. 
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    An in situ photochemical fluorescence probe method for the determination of DNAwith sodium 9,10-anthraquinone-2-sulfonate(AQS) as a photochemical fluorescence probe was developed for the first time.It was based on the conversion of AQSinto an intensively fluorescent product on irradiating with UVradiation.The photochemical reaction is decelerated by DNA.The determination can be carried out by measuring the fluorescence intensity at a fixed time.The calibration graph was linear in the range 0～80 ng/mL CT DNA(r=0.9991), the limit of detection was 3.2 ng/mL CT DNA(n=9).The kinetic behaviour of the photochemical reaction and the effects of some experiment conditions were investigated and discussed in detail.The results of absorption spectra experiments and competitive binding experiments suggest that the interaction between AQSand DNAmay be intercalative.
    A Neural Network Algorithm for Pattern Classification of Three Chemical Substances
    FENG Wei, HU Shang-Xu
    1996, 17(11):  1708-1710. 
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    A hybridized algorithm of artificial neural network(ANN) was used to carry out the task of pattern classification on data from Taguchi Tin-oxided sensors for the three substances acetone,ethanol and methanol.It made use of the Gradient Descent(GD) method with Simulated Annealing(SA) and Genetic algorithm(GA) to speed up the calculation and improve the classification accuracy.It performed good to elude local minima,and consequently improved the accuracy of classfication. Fig.1 shows the ANN learning procedure.The calculation results between two comparison methods are shown in Fig.2 and in Fig.3 for continuing training. By combining the advantages of both SA,GAand GD,extensive tests show that this is a better approach as a pattern recognition method to construct Artificial Nose.
    Determination of the Diffusion Coefficient of La in Hg by Chronoamperometry
    XU Yi-Xin, MOU Lan, ZHANG Chang-Geng
    1996, 17(11):  1711-1713. 
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    Two methods were used to prepare La amalgam.One was displacing La3+ ion with Na amalgam, the other was mercuty cathode electrolytic method.The diffusion coefficient Dof La in Hg was determined by chronoamperometry in NaAc-HCl-NaSO4 pH=6 supporting electrode to be(4.90±0.11)×10-6cm2/s at 25℃
    Catalytic Current for EC' Reaction with Finite Linear Diffusion Space
    WU Zhi-Bin, DONG Shao-Jun, WU Hao-Qing
    1996, 17(11):  1714-1716. 
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    In this paper,equations for chronoamperometric current and linear sweep voltammetry are derived for the case where the EC'catalytic reation occurs at an electrode with finite linear diffusion space.The analytical expression for chronoamperometric current is given and voltammogram is obtained by numerical calculation.The voltammogram varies with both the kinetic parameter,P=kfCZ*Fd2/D, and the scan rate parameter,w=nFvd2/RTD,where the kf is the rate constant of the catalytic reaction,CZ*F is the bulk concentration of catalyst in film,d is the thick of film,v is the potential sweep rate.Others have the normal meaning.The dependence of the current potential curves on these two parameters is discussed.From this dependence,a concept of quasi-steady-state catalytic current is developed.
    Studies on Aldol Condensation of Bicycloazastannoxides with Aldehyde
    WANG Ji-Tao, YANG Xiao-Ping, XU Yu-Ming, WANG Shan-Wei
    1996, 17(11):  1717-1720. 
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    Since the structures of bicycloazastannoxide in some way conform VB6 system,the Schiff base of diphenylstannic complexes(PhSnL1H)was chosen to be the object of investigation.Its pKa in DMSO was found to be 17.6.It was subjected to react with aldehydes,and 7 novel condensation products(PhSnL1CHOHR Ⅰ-Ⅶ)β-hydroxy-α-amino acid ligands of organo-tin complexes were obtained,their IR,1H NMR,119Sn NMR and elementary analytical data were proved to have the assigned structures.
    The Synthesis and Structure of Aromatic Heterocyclic New Type Macrocyclic Compounds(Ⅰ)──The Synthesis and Structure of 1,3,4-Oxadiazoles Macrocyclic Polyether
    ZHOU Jian-Min, HUA Wen-Ting, YANG Qing-Chuan
    1996, 17(11):  1721-1724. 
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    Four new type of compounds containing 1,3,4-oxadiazoles macrocyclic polyethers A,B,C,Dwere synthesized with[1+1]or[2+2]cyclization of 2,5-bis-hydroxyphenyl 1,3,4-oxadiazole and relevant ethylene glycol or polyethylene glycol.Also,the stereo structure of Awas elucidated by X-ray diffraction.
    Studies on Syntheses and Water Sensitivity of Ferrocenylmethylaminoalkoxy Silanes
    LI Bao-Guo, A Juan, BIAN Zhan-Xi, ZHAO Hai-Ying
    1996, 17(11):  1725-1728. 
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    The reaction between ferrocenylmethylaminoalcohols and chlorosilanes gave 12 compounds of ferrocenylmethylaminoalkoxy silanes in one-step method and in relatively good yield.The synthetic method and relationship between the water sensitivity and structures of the compounds were investigated.The experimental results show that both of the aminoalcohols FcCH2NHCH(R')CH(R″)OH(Fc=C5H5FeC5H4,R'=H,C2H5;R″=H,CH3)and chlorosilanes R(CH3)2SCl(R=CH3,C2H5,n-C3H7,n-C4H9)have influnce on the reaction.The more bulky R,R'and R″,the smaller the reaction rate.The title compounds FcCH2NHCH(R')CH(R″)OSi(CH3)2R,are relatively sensitive to water.The more bulky R,R'and R″,the more stable the compound to water.The structures were characterized by elementary analysis,IRand 1H NMR.
    ^Advance of Pesticide Research Abroad Synthesis and Properties of O-(1-Methylthioethlieneamino)thiophosphoramidates
    XING Xiao-Dong, HE Shui-Ji, XU Chang-Biao, TIAN Wei, YANG Xue-Jin
    1996, 17(11):  1729-1733. 
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    A series of novel O-(1-methylthioethylieneamino)thiophosphoramides were synthesized,and their structures were confirmed by EA,1H NMR,IR and MS.The preliminary tests of pesticidal activities show that two compounds of them have good insecticidal activities.
    The Total Synthesis of (±)-Epi-mayol(Ⅱ)
    WANG Gui-Yang-Sheng, SU Jing-Yu, ZENG Long-Mei
    1996, 17(11):  1734-1737. 
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    The total synthesis of(±)-epi-mayol(1)using hydroxygeranial(2)and linalool (5)as starting material was described.2,6-Dimethyl-8,8-diethoxy-octa-2,6-dieneyl-p-tosylate(4)was prepared from(2),and 8-hydroxy-3,7-dimethyl-octa-2,6-dieneyl-phenylsulfone(7)was prepared from(5).Then(4)and(7)were condensed in the presence of NaNH2 afford to the intermediate 16-hydroxy-3,7,11,15-tetramethyl-9-phenylsulfonyl-hexadeca-2,6,10,14-tetraene-al(8).8 was converted to bromide(9)and followed by ring closure in the presence of Cr(Ⅱ)to form a macrocyclic diterpene.The resulted mixture was purified by flash chromatography with high performance silicagel to obtain pure(10).Finally,the sulfonyl group of 10 was eliminated by sodium amalgam to give 1 in 8.5% overall yield.
    A Preliminary Study on the Possibility of Screening Small Peptide in Peptide Library
    QI Jie, FANG Rui, ZHOU Hui, LI Wei, SHEN Jia-Cong
    1996, 17(11):  1738-1741. 
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    Peptide libraries have been successfully used in the field concerning molecular interactions,such as antigen-antibody,receptor-ligand,enzyme-inhibitor and so on.These research results show that a few critical residues which can form hydrogen bond or ionic bond in proteins make a major contribution to the interactions of proteins.This paper reports the possibility of screening short peptide in phage hexa-peptide library using DGGSAA as a model.The results show that it is possible to screen the short peptide containing the residues forming hydrogen bond and ionic bond in peptide library,which improved the specificity of screening greatly and the recovery of phage reduced from 0.001 %to 0.00022%.That indicates that the interactions between short peptides is strong enough to survive the screening and it supposes a simple model to research molecular recognition with peptide libraries.
    Studies on Action Receptor to Natural Product Epibatidine
    XU Jian-Ping, HE Dong, WANG Zhi-Zhong, SHEN Jia-Cong, GAO Lian-Xun, SONG Ya-Ru
    1996, 17(11):  1742-1743. 
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    According to the theoretical calculation of epibatidine and nicotine by using AM1 method,we made a good explaination for the phenomenon that the analgetic action of epibatidine doesn't be reversed by naloxone as usual analgetics for the first time,and this result supports the results of Daly's experiment.In addition,as epibatidine and micotine have many similarities such as structure,activity and other qualities,so we believe that they also have the same action receptor-nicotine receptor.
    The Oxidation of the Secondary Hydroxyl Group in Monosaccharides and Electrochemical Behavior of the Oxidants
    CAO Ling-Hua, LIU Yu-Ting
    1996, 17(11):  1744-1746. 
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    D-Fructopyranose,D-xylofuranose and L-arabinofuranose with different protective groups were oxidized by DMSO,PDCor PCC.The preferable oxidizing agent and the preferable condition have been studied.The structures of products were confirmed on the basis of optical rotations,elementary analysis and IR,1H NMRand 13C NMRspectral data.
    Two New Scalarane-type Sesterterpenes Phyllactone H and I from the Sponge Phyllospongia sp.
    WAN Yi-Qian, SU Jing-Yu, ZENG Long-Mei, WANG Ming-Yan
    1996, 17(11):  1747-1749. 
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    Two new scalarane-type sesterterpenes namely phyllofolactones H(1),I(2)have been isolated from the sponge Phyllospongia sp.collected in the South China Sea.The structures of these compounds were elucidated by interpretation of spectra data.The new sesterterpenes possess α,β-unsaturated γ-lactone moieties and have hydroxyl groups attaching the C-12 and C-16.
    Theoretical Study on the Structure and Spectra of C62O3
    HAO Ce, TENG Qi-Wen, WU Shi, SHANG Zhen-Feng, ZHAO Xue-Zhuang, TANG Aao-Qing, FENG Ji-Kang
    1996, 17(11):  1750-1753. 
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    INDO calculation was used to study the two structures of C62O3:one of C2v symmetry and the other of Cs symmetry.A patch of topology of C60 was employed to discuss the symmetry of additive and cycloadditive products of C60 and related to 13C NMRresults.Stability comparison was made between the devivatives of three-membered and five-membered rings.The calculated electronic spectrum for C62O3 C2v)is in agreement with the experimental results.
    Some Important Factors in the Photodimerization Reaction of α,ω-Biscoumarin Long Chain Compounds
    LIU Tain-Jun, WU Shi-Kang
    1996, 17(11):  1754-1759. 
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    The effects of salt,solvent, viscosity and the effects of length, flexibility of spacer between chromophores on the photodimerization reaction of α,ω-biscoumarin long chain polyether compounds have been studied in this work.With the aids of UVabsorption,fluorescence and 1H NMRspectra,the conformation of the title compounds under different conditions was analyzed. Based on the results obtained,the behavior of photodimerization of these compounds in different cases was discussed and explained.
    Numerical Analysis to the Catalyst Layer Model of PAFC Air Electrode
    WEI Zi-Dong, GUO He-Tong, TANG Zhi-Yuan
    1996, 17(11):  1760-1763. 
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    A mathematic model is proposed to characterize the performance of air electrodes in phosphoric acid fuel cells(PAFC).Stefan-Maxwell equation is used to describe the mass transfer of multicomponents in hydrophobic pores of the catalyst layer.The latest development in O2 reduction research is taken into account of the model establishment.A method to estimate the parameters introduced to the model is also recommended.Aprogram of solving mathematic model is programmed with FORTRAN 77.The potential current functions obtained from calculation with the present model are very close to those from experiments.Some quantitative conclusions on air electrodes were drawn through the analysis of air electrode process with the aid of the present model.
    The Photoelectrochemical Behavior of Lead Electrodes in H2SO4 Solution
    ZHAI He-Sheng, YOU Jin-Kua, LIN Zu-Geng
    1996, 17(11):  1764-1768. 
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    The mechanism of photoresponse during the anodic oxidation of Pb electrode was investigated.The results showed that there was photoactivation during the oxidation of Pb electrode under illumination when the electrode potential was over 0 V.The study of the cathodic photoresponse of lead anodic films in the cathodic potential region showed that the lead anodic films could produce cathodic and anodic photocurrents. The cathodic photocurrent was produced by p-type lead oxide in the film, and the anodic photocurrent might be produced by the lead oxide,which formed p-n junctions.The measurement of photo-potential was used to study the constant current polarization of lead electrodes in H2SO4 solution.
    Effect of Different Correlation Functions on Convergence Pattern in the CFHHGLF Calculations of the Lithium Atom
    WANG Yi-Xuan, DENG Cong-Hao
    1996, 17(11):  1769-1772. 
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    Three simple spatially symmetric correlation functions exp[-α(r1+r2+r3)](variable parameter a by E+3/2α2=0,constant α,2.76 and the nuclear charge z,respectively)are used to carry out the correlation-function hyperspherical-harmonic and generalized-Laguerre-function(CFHHGLF) calculations of the ground state lithium atom.With 215 symmetric bases of the two-dimensional irreducible representation for the permutation group S3,constructed from nine-dimensional hyperspherical harmonics,the CFHHGLF calculations provide the best eigenenergy of -7.473122 a.u.as α=z,followed by α=2.76,-7.450788 a.u.,and the variable parameter α,-7.413668 a.u.,while from the convergence rate in the hyperradial direction,the variable parameter α generates the fastest convergence eigenenergy,and as α=.76 the eigenenergy slowly converges,as α=z the eigenenergy converges only when over 100 symmetry bases are taken into account.In view of the accuracy as well as the stability of the eigenenergy,symmetric exponent correlation function with α=z should be considered to obtain high precise eigenenergy in hyperspherical harmonic method.
    Selective Catalytic Reduction of Nitric Oxide by Propene over Heteroatom ZSM-5 Zeolites
    ZHANG Wen-Xiang, JIA Ming-Jun, ZHANG Chun-Lei, WU Tong-Hao, AO Xue-Ju
    1996, 17(11):  1773-1775. 
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    The selective catalytic reduction of nitric oxide with propene in the presence of oxygen has been studied over various transition metal substituted heteroatom ZSM-5 zeolites.It was found that most of MZSM-5 zeolites(M=Co,Cr,Cu,Fe,Mn,Ni,Ti,V,Zn)were effective catalysts for the reaction,Among the samples tested, FeZSM-5 shows the hightest activity around the reaction temperature of 673 K.
    Study on the Performance of Methane Aromatization of Ni Modification of Mo/HZSM-5 Catalyst
    WANG Dong-Jie, ZHANG Yi-Ping, FEI Jin-Hua, ZHANG Xiao-Ming
    1996, 17(11):  1776-1778. 
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    The effects of conversion of CH4 over Mo-Ni/HZSM-5 catalysts under a non-oxidizing condition with different temperatures,different conditions of pretreatment and different loadings of Ni were investigated.The results indicate that when Ni/Mo molar ratio is 0.05,the conversion of CH4 at 973 Kcan reach 11.3%,and the selectivity of aromatic hydrocarbon can reach 97.1% It′s shown that adding a certain quantity of Ni is beneficial to the conversion of CH4,the maximun conversion of CH4 at 1023 Kcan reach 15.9%.The effect of reaction with pretreatment by using N2 is better than that in the cases of H2,CH4 or air.The results of NH3-TPD-MSshow that the centre numberes of strong acidity and weak acidity both on the Mo-Ni/HZSM-5 catalysts are more than that on the Mo/HZSM-5 catalyst.This might be one of the reasons that the activity of methane aromatization is increased over Mo-Ni/HZSM-5 catalyst.
    Ab Initio Study on the Gas-phase Reaction of M++BrCN→MCN++Br
    ZHU Rong-Shun, DAI Shu-Shan
    1996, 17(11):  1779-1781. 
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    Ab initio quantum chemical calculations with averaged relativistic effective potentials(AREP),including the effects of electron correlation,are performed on the reactions, M++BrCN→MCN++Br,Where M+ is the first-row transition-metal singly charged cation.The highest barrier for the reaction is found for the Mn+(485.54 kJ/mol),which is due to the large loss of exchange energy upon bond formation and large repulsion of the 4s electrons.According to the calculated barrier height,the reactivities are in agreement with experimental trends:V>Mn,Fe;Co>Cr.However,contrary to the experimental trends Sc>Ti.In our study,the transition state for scandium cation is considerably higher than that for titanium cation,because titanium cation is in the less repulsive state 4F(d2s1)since it has lower s-population,and therefore it has lower barrier.We can explain why the reaction extent of the first row metal cations with cyanogen bromide was only a few percent,one of the main reasons is that the barrier height is too high.
    Effect of Ce4+ on Preferred Orientation Nickel
    HUANG Ling, XU Shu-Kai, TANG Jiao-Ning, YANG Fang-Zu, ZHOU Shao-Min
    1996, 17(11):  1782-1784. 
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    Ni deposit with(220)highly preferred orientation was obtained with potentiostatic method in solution containing 1.0 mol/L NiSO4,0.5 mol/L H3BO3,1.9×103mol/L CeSO(4)2.The deposit with highly preferred orientation was examined with X-ray diffraction and scanning tunneling microscope.It is shown that the Ni deposit has(220)highly preferred orientation,with texture degree of 95 percent and layer-shaped structure.The electrochemical behavior of the solution was studied with cyclic voltammetry.
    Studies on Structure of Magnesium Aluminium Hydroxide Positive Sol
    HAN Shu-Hua, ZHANG Chun-Guang, HOU Wan-Guo, SUN De-Jun, WANG Guo-Ting
    1996, 17(11):  1785-1787. 
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    Using the coprecipitation method,magnesium aluminium hydroxide sol charged positive was prepared.The structure and composition were studied with powder XRD,TEM,TGA-DTA, FT-IRand chemical analysis.Results showed that the structure of magnesium aluminium hydroxide was hydrotalcite-like,and belonged to hexagonal system;lattice constants a and c both increased with the increase of the molar ratio of Mg/Al.The shape of magnesium aluminium hydroxide particles is hexagonal plate and the mean particle size is 11.7nm.Three peaks of obtained magnesium aluminium hydroxide caused by weight losses were detected:the first peak(around 160 ℃)might be attributed to physical adsorption water and interlayer water;the second one(around 258℃)was due to elimination of crystalline water and the third one(around 400℃)was due to the dehydroxylation of the mixed metal hydroxide layers.The first and the second weight loss peaks were superimposed and widen when the molar ratio of Mg/AI was above 2.84.
    Studies on Synthesis and Controlled-release of Polymer Drug Using Lactic Acid-Phosphate Copolymer as Drug Carriers
    FAN Chang-Lie, LI Bing, LIU Zhen-Hua, ZHUO Ren-Xi
    1996, 17(11):  1788-1791. 
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    Akind of polymer drug,using 5-flurouril as model drug,lactic acid-phosphate copolymers as polymer drug carriers,was synthesized.The copolymers were characterized by 1H NMR,IRand UVspectroscopy.The contents of 5-fluorouril were determined by UVspectroscopy.The drug release in vitro of the copolymers was studied and the influence of the copolymer composition on the drug release in vitro was investigated.
    The Oxidation of Polymethyl Acrylate and Its Model Compound by Molecular Oxygen in Dark
    DONG Yu-Ping, QIU Kun-Yuan, FENG Xin-De
    1996, 17(11):  1792-1795. 
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    The oxidation of polymethyl acrylate(PMA) and its model compound methyl 2-methylbutyrate with molecular oxygen in dark have been studied.The experimental results showed that the two esters could form a contact charge transfer complex(CCT)with O2 respectively.When O2 was bubbled to solution of ester and kept for several hours and then N2 was bubbled to the solution again,the UVabsorption of the CCTcould not completely disappear and a remaining peak was formed, and the strength of the remaining peak increased with the increasing of time.It indicated that the new compound was produced,and CCT played an important role in the oxidation of the two esters with O2.Furthermore from IR and NMR spectra it was found that the hydroperoxide was formed at the a-Cof methyl 2-methylbutyrate.As well as the unsaturated methyl 2-methylbutenate which was produced in the further oxidation of methyl 2-methylbutyrate with O2.
    Gas Permeation Propeties of Cardo Polyaryletherketones Containing Different Alkyl Substituents
    WANG Zhong-Gang, CHEN Tian-Lu, XU Ji-Ping
    1996, 17(11):  1796-1799. 
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    The gas permeation properties of a series of cardo polyaryletherketone materials are reported.In this series,hydrogen atoms of benzene rings on the backbone are systematically replaced with different alkyl substituents.The effects of temperature and structure variation on gas permeability and selectivity are discussed in detail.The experimental results revealed that the polyetherketone obtained by the introduction of dimethyl and diisopropyl substituents to phenolphthalein unit is 3～6 times more permeable than the unmodified one for the gases studied.
    Synthesis of α-Glycosyl-stevia-sugar Catalyzed by Glycosyltransferase(I)
    SHI Zuo-Qing, ZHU Bo-Ru, SHI Rong-Fu, LI Xiao-Ting, HE Bing-Lin, JIA Zhi-Fen, QIAO Jin-Sheng
    1996, 17(11):  1800-1803. 
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    Glycosyltransferase GT-1 was used to catalyze the synthesis of α-glycosyl stevia sugar. Various influent factors were discussed.The result showed when the reaction came to a certain extent,transglycosylated amount changed very little with increase of amount of enzyme and starch.The taste of stevia sugar promotes greatly after transglycosylated treatment.
    The High Strength Disclination Points in the Schlieren Texture of the Schiff Base Type Liquid Crystal
    ZHANG Qi-Zhen, CUI Li, SUN Ji-Run
    1996, 17(11):  1804-1806. 
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    The observation of smectic schlieren textures with singularities of high stgrength in the sample is reported.The sample is Schiff-Base type liquild crystal with ortho-hydroxy, 4-undecenoyloxy resorcylidene-4′-decyloxyaniline.The highest strength of these singularity points is —8,the singularity points with S=—6,—4,—3,—2 are also observed,and their stability is good.The forming process of the singularity points with high strength is also observed,the center of the disclination points is an isotropic area.
    Crystalline Behavior and Critical Crystalline Sequence Length of Propylene/α-Olefin Copolymer
    CHEN Hui, WANG Jian-Guo, ZHANG Xue-Quan, PANG De-Ren, HUANG Bao-Tong
    1996, 17(11):  1807-1809. 
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    The melting points(Tm),crystalline temperature(Tc)and crystallinity(Xc)of propylene/α-olefin(pentene-1,octene-1 and decene-1)copolymers have been investigated. The results show that the Tm,Tc and Xc of the copolymers are lower than those of propylene homopolymer,indicating that lower α-olefin incorporation in copolymer has strongly hampered the crystallization of propylene.From critical crystalline sequence length of several propylene/α-olefin copolymers,it can be seen that a long chain α-olefin has much stronger effect on crystallization of PPthan a short α-olefin does.
    Reactive Compatibilization of Polystyrene/Polyethylene Blends Containing Basic Functionalized Polymer
    HU Jing, ZHANG Bang-Hua, SONG Mou-Dao, ZHOU Qing-Ye
    1996, 17(11):  1810-1812. 
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    Blends of polystyrene(PS) with polyethylene(PE)or PE melt grafted with maleic anhydride(PE-g-MAH) and copolymer[Poly(St-Co-DMA)] of styrene(St)with dimethyl amino ethyl methacrylate(DMA) were prepared by blending in a Brabender mixer.The morphology of these blends was found to have the typical morphology of incompatible blends,where their reactive PS/PE-g-MAH/Poly(St-Co-DMA)blends showed a finer morphology,the particle size was greatly reduced and the size distribution became more uniform.This was attributed to the stronger polar interaction between the acidic anhydride and basic amino groups.Furthermore,the dynamic mechanical analysis measurements showed that the two glass transition temperature(Tg)peaks of reactive blends were closer than those of corresponding nonreactive blends. The mechanical properites of blends were improved.
    Compatibility and Specific Interactions in Poly(β-hydroxybutyrate)and Poly(p-vinylphenol)Blends
    XING Pei-Xiang, DONG Li-Song, FENG Han-Aiao, AN Yu-Xian, ZHUANG Yu-Gang, FENG Zhi-Liu
    1996, 17(11):  1813-1815. 
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    The miscibility and specific interactions in poly(β-hydroxybutyrate)(PHB)/poly(p-vinylphenol)(PVPh) blends were studied by differential scanning calorimetry)DSC),fourier transform infrared(FTIR)spectrometer and high resolution solid state 13C NMR.A single composition-dependent glass transition temperatures were obtained by DSCwhich indicate the blends of PHB/PVPh were miscible in the melt state.The experimental glass transition temperatures were fitted quite well with those obtained from Couchman-Karasz equation.The FTIRstudy shows that the strong intermolecular hydrogen bonding exists in blends of PHBwith strong proton acceptor and PVPh with strong proton donor and is the origin of its compatibility.The CPMAS 13C NMR spectra also show that the strong hydrogen bonding exists in PHB/PVPh blends.From the T1ρH relaxation time it follows that the blends of PHB/PVPh(40/60,20/80)studied are completely homogeneous on the scale of about 3.2 nm.
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