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    24 June 1996, Volume 17 Issue 6
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    Articles
    Hydrothermal Synthesis of Nanosized SnO2
    CHENG Hu-Min, MA Ji-Ming, ZHAO Zhen-Guo, QI Li-Min
    1996, 17(6):  833-837. 
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    Uniform nanosized SnO2 particles were prepared by a hydrothermal method using SnC14·5H2O as the starting material.The influences of reaction temperature,acidity in reaction medium and concentration of reactant on the formation,morphology and particle size of SnO2 crystallite were investigated.The XRDanalysis showed that the products formed at different temperatures(120～220℃) in acid medium were all tetragonal SnO2.With raising reaction temperature,particles grew gradually.Their particle sizes were ca.2 nm(120℃ )～6 nm(220℃) in [SnCl4]=1 mol/L,PH=1.45,respectively.Decreasing the acidity in reaction medium appropriately(for example PH=1.45) favored a decrease in particle size and an increase in yield.
    A Technical Design and Experiment of the Chemical Vapor Deposition of AIN Film
    XIE Song, LIU Xi, MENG Guang-Yao
    1996, 17(6):  838-842. 
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    Thermodynamic analysis and a technical design and experimental results for the chemical vapor deposition(CVD) of AINfilm from AIBr3-NH3-N2 system are presented.At various deposition temperatures,input gas flow rates and total pressure,the equilibrium partial pressures of the major gaseous species are calculated.The effects of precursor temperature and gas flow rate on the theoretical deposition rate of AINfilm are estimated.And theoretical results are compared with those of the experiments by a microwave plasma CVDof AINthin films.
    A New Method for Synthesis and Characterization of p-Alkoxyl-phenyl-benzoporphyrin
    WANG Xing-Qiao, GAO Shuang, CAO Chang-Sheng, SHI Tong-Shun, YU Lian-Xiang, CAO Xi-Zhang
    1996, 17(6):  843-848. 
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    Anew sealed-melting method was used to synthesize five series of p-alkoxyl-phenyl benzoporphyrins(25 kinds).Alkoxyl was linked up with zinc benzoyl acetate first, then the resulting chain formed a ring with phthalimide.The structures of 10 ktnds of the porphyrins were characterized by UV-Vis,IR,MSand elementary analysis.Their properties were studied preliminarily.
    Studies on Infrared Spectra of Bistetraphenylmetalloporphyrin Dimers Linked by a Flexible Alkoxy Chain
    JI Sheng-Fu, KOU Yuan, JI Wei-Jie, LI Shu-Ben, LIU Zhan-Liang, HUANG Jin-Wang, JI Liang-Nian
    1996, 17(6):  849-853. 
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    The FTIRspectra(3600～150 cm-1)of bisteraphenylmetalloporphyrin dimers linked by a flexible alkoxy chain were measured and investigated.The major bands have been empirically assigned in comparison with a large number of porphyrins and metalloporphyrin complexes.The metal sensitive bands were found at 1558;2,l472.2,1401.9,1350.5,l 001.7,965.9,877.3 and 798.8 cmr) The structure sensitive bands of both the metal and the alkoxy chain were found at l 595.1,1491.1,851.1 and 723.8cm-1.The vMn-Cl and -1,vFe-Cl were found at 3l8.2 and 371.4 cm-1 respectively.The vibration coupling between the M──N and the porphyrin ring deformation is Co(Ⅱ)>Mn(Ⅲ)>Fe(Ⅲ).The vibration coupling between the M-Nstretching modes and the porphyrin ring deformation is MP>Mp-MP.The vibration coupling between the M-Nbending modes and the porphyrin ring deformation is MP<MP-MP.
    A Study of Tetraaza[14] Annulene Nickel(Ⅱ) Complexes(Ⅰ)──Syntheses and Characterizations of Substituted Tetraaza[14]Annulene Nickel(Ⅲ) Complexes
    ZHANG Wen-Wei, LI Dong-Wen, XU Er-Jie, MENG Qing-Jin, YOU Xiao-Zeng
    1996, 17(6):  854-858. 
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    The property of tetraaza[14] annulene complexes is very similar to that of porphyrin and phthalocyanin compounds.In this paper, two tetraaza[14] annulene nickil (Ⅱ)macrocycles were synthesized by the reaction of template effect,six dibenzoyl tetraaza[14]annulene complexes were prepared by the electrophilic substitutions, which have not been reported before.All were characterized by EA, IR, UV, 1H NMR, MS.
    Synthesis and Charaterization of C60 Tetramethoxy Derivative
    GAN Liang-Bing, ZHOU Sheng, JIANG Jian-Feng, HUANG Chun-Hui, WU Yi, LU Mu-Jian, PAN Jing-Qi
    1996, 17(6):  859-860. 
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    Methanol reacts photochemically with C60 in the presense of 1,4, 7, 10-tetraazacyclododecane to yield a tetramethoxy C60 derivative C60(OMe)4.The compound has been characterized by FDMS,1H NMRand FTIR spectra.
    Artificial Neural Networks Applied in the Analysis of Chemical Data(Ⅰ)──Approximation for Trend and Over-fitting
    LIU Ping, LIANG Yi-Zeng, ZHANG Lin, YU Ru-Qin
    1996, 17(6):  861-865. 
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    Over-fitting in feedforward multilayer neural network was studied in this paper.Approximation error and the degree of approximation were introduced as the evaluation index for modelling in ANN.Numerical simulation and real pharmaceutical spectrophotometricdata were analyzed by the proposed method.Results showed that the index was simple,convenient and described properly the quantitative degree of approxirnation for trend by ANN.
    Studies on the Ions' Effect on the Binding Interaction Between HP and BSA
    FENG Xi-Zeng, JIN Rui-Xiang, QU Yun, HE Xi-Wen
    1996, 17(6):  866-869. 
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    We studied the binding interaction between hematoporphyrin(HP) and bovineserum albumin (BSA) in solution with flourescence method.The binding constant is KA 2.2×104 and the number of binding site is 1.With the Forster non-radio energy transfer theory,we calculated the distance beween energy donor and receptor as well as the energy transferefficiency in the binding reaction.Furthermore, we studied the interaction between severalions(cations and anions) and BSA.The order of quenching ability of these ions is; Cr(Ⅵ)>Fe3+>Cu2+>NO2->Br-,and the competing reaction for BSA between the ions and HPisdiscussed.We tried to illustrate the possible effect of the ions on the transfer and absorptionof HPin the process of cancer photochemical treatment.
    Studies on the Piezoelectric Immunosensor for the Determination of α-Fetoprotein (AFP)
    CHU Xia, LIN Zhao-Hui, SHEN Guo-Li, YU Ru-Qin
    1996, 17(6):  870-873. 
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    Apiezoelectric immunosensor has been developed for the determination of AFP.The crystal is AT-cut and has a basic resonant frequency of 9 MHz.Immobilization of theantibody of AFP(anti-AFP) to the crystal's surface is accomplished via a CNBr-activatedcopolymer coating of hydroxyethyl-methacrylate (HEMA )and methyl-methacrylate(MMA).The effects of immobilization method,the amount of copolymer coating and the reaction time between antigen and antibody are studied.Under the optimized conditions, the frequency shifts are linearly dependent on the AFPconcentrations in the range of 100~800ng/mL.Experimental results show that the piezoimmunosensor has good reproducibility, selectivity and sensitivity.Other antigens presented in human serum do not interfere with the sensor's response.Further, the valent value of AFPand anti-AFPand the affinity constant of immunoreaction in this experimental system are calculated.The analytical results given by this approach are in satisfactory agreement with those given by Radial Immunoassay(RIA).
    A Study on Single-sweep Oscillopolarography of Ciprofloxacin Lactate
    WANG Xiu-Ling, ZHANG Shu-Min, HE Chun-Xiang
    1996, 17(6):  874-877. 
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    The polarographic and voltammetric behavior of ciprofloxacin lactate (CFL) and its application were studied.In 0.02 mol/L NH4Cl-NH3. H2O buffer solution (pH= 8.3),a well-defined reduction peak was yielded by CFL.The peak potential(Ep) is about -1.61 V (vs-SCE).Alinear relationship holds between the differential peak height and the concen tration of CFLin the range of 3.9×10-8～1.8×10-5 mol/Land 1.8 ×10-6～1.1×10-5 mol/L, respectively, with r= 0.9997.The limiting detection is 2.5×10-8 mol/L.Most of metallic ions do not interfere the determination.This method is used to determine CFLin raw samples and injections with RSD 0.38%～0.72% and recoveries 99.2%～101.4%, and can also be used to determine the trace CFLin serum, plasma and urine samples.It may provide a simple, rapid and sensitive method for determining clinical medicine and pharmacokinetics.The experimental results show that the reduction of CFLbelongs to an irreversible process of reactant adsorption.The electrode reaction mechanism was preliminarily presented.
    Studies on the Interaction Between Photosensitizer Methylene Blue and Different Organic Solvents
    FENG Xi-Zeng, HE Xi-Wen, SHEN Han-Xi
    1996, 17(6):  878-882. 
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    The spectrophotometric characteristics of methylene blue in different organic solvents have been studied in this paper.From application of Kasha's theory on the difference spectrum between MBmonomer and dimer, we have estimated that the distance between monomer planes of MBranges from 1.345 nm to 1.425 nm and these planes form the cross angle 82.9～87.5°in dimer molecules.In order to obtain information on the solution state of different solvents with methylene blue, interaction between different solvents and MBhave been investigated by the analysis of UV-Vis absorption spectra in terms of a modified McRas's equation.The sum of the dispersion and induction force of the MBestimated from the equation is 21.3 kJ/mol, the orientation force as 20.5 kJ/mol, the hydrogen bonding as 0.17 kJ/mol in ethanol solution.The sum of the dispersion and induction force of the MBestimated from the equation is 25.9 kJ/mol, the orientation force as 20.1 kJ/mol in dimethyl sulfoxide solution.
    Capillary Zone Electrophoresis Separation of Nine Purine Bases
    ZHAO TaO, LIU Qi-Ping, CHENG Jie-Ke
    1996, 17(6):  883-886. 
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    This paper reports the separation and determination of caffeine,9-N-dihydroxypropyltheophylline, theobromine, adenine, guanine,theophylline, xanthine, uric acid and 6-mercaptopurine by capillary zone electrophoresis, In an uncoated fused silica capillary(70cm ×75μm i.d., effective length 63 cm), the above mentioned materials can be separated within 7 min in the optimum conditions;0.01 mol/LpH=10 borate buffer,30℃,25 kV,260 nm and 1s load.Efficiency to 3.0×105 the number of theoretical plate is achieved.The detection limit is fmol.The results of urine sample analysis are satisfactory.
    Spectra of Resonant Luminescence and Double Scattering of Mercury(Ⅱ)-Thiocyanate-Victoria Blue 4R System and Their Analytical Application
    LIU Shao-pu, LIU Zhong-Fang
    1996, 17(6):  887-892. 
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    This work studied the spectra of resonant luminescence(RL),double scattering(DS)and anti-double scattering(ADS)of the ion-association complex of[Hg(SCN)4]2- withVictoria blue 4R(VB 4R).The spectral characteristics,the effect factors and the optimum conditions of the reaction have been investigated.The quantitative relationships of the IRL,IADS and IDS to the concentration of mercury were established.Anew analytical method for determination of trace mercury(Ⅱ) was proposed.And we have a preliminary discussion on relative mechanism.
    A Study of Selective Permeability of β-Cyclodextrin Derivatives Self-Assembled Monolayers on Gold
    HE Pin-Gang, FANG Yu-Zhi, SUZUKI Iwao, OSA Tetsuo
    1996, 17(6):  893-895. 
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    The ordered self-assembled monolayers of β-cyclodextrin derivatives on gold have been prepared with two kinds of lipoyl-β-cyclodextrin derivatives which are more flexible than heptakis(dodecyl sulfide)β-cyclodextrin, The evidence of selective permeability for the organic species which can form host-guest inclusion complexes with β-cyclodextrin was obtained by cyclic votammetry for electroactive species of [Fe(CN)6]3-/[Fe(CN)4]4- and ferrocence carboxylic acid(FCA) on the self-assembled monolayers electrode.FCAcan permeat through the β-cyclodextrin monolayers by complexing with β-cyclodextrin,However,the electrode reaction for[Fe(CN)6]3-/[Fe(CN)4]4 is efficiently inhibited by the β-cyclodextrin cavity.On the other hand,the permeability for FCAwas shown to be able to be inhibited by adding other organic guests such as borneol and ursodeoxycholic acid.The promising applications of the selective permeability of β-cyclodextrin self-assembled monolayers are for selective membrane transport and selective electrochemical analysis.
    Single Electron Transfer Reactions of Enamines with Polyfluoroalkyl Iodides──Novel Synthesis of α-Polyfluoroalkyl Ketones and Aldehydes
    HE Hai-Ying, ZHAO Cheng-Xue, WENG Zhong-Yuan, BAI Ling-Jun, LIAO Ren-An
    1996, 17(6):  896-900. 
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    Fairly high yields of α-polyfluoroalkyl ketones(aldehydes) formed in the reactions of enamines with polyfluoroalkyl iodides were characterized by UV,IR,MS,1H NMR,19F NMRand elemental analysis,The electron transfer in nature of these reactions was proved by spin trapping and inhibition experiments.The addition of catalytic amounts of SmI2 has significantly shortened the reaction time and increased the yields of α-polyfluoroalkyl ketones.
    Chromatographic Features and IR Spectra of Ferrocenylimines and Their Cyclomercurated Derivatives
    LIU Yuan-Hong, YU Zheng-Yan, HUO Shou-Quan, WU Yang-Jie
    1996, 17(6):  901-905. 
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    The comparative studies on the chromatographic affinity of ferrocenylimines and their derivatives of mercury have showed that the cyclomercurated compounds exhibit higher Rf values than the corresponding starting ferrocenylimines,which has been explained in terms of the N→Hg intramolecular coordination,The substituent effects on the Rf values show that the higher the electron density in the imino nitrogen atom is,the lower the Rf value is.The examination of UV-Vis spectra of these compounds showed that an intramolecular coordination,N→Hg,exists in the molecules of cyclomercurated compounds,The effect of the substituents situated at the carbon atom of the imine group and in the N-phenyl ring on the UV-Vis spectra was investigated.Compared with the λmax of the ferrocenylimine in which there is no substituent in N-phenyl ring,a good linear relationship was found between the △λmax of the π-π*CTband and the Hammett-Brown constants σ+.In addition,the application of IRrules for characterizing the structures of substituted ferrocenes to the system studied has also been examined.
    Excited-state Intramolecular Proton Transfer and Spectroscopy of 2-(2'-Hydroxy phenyl) benzoxazole in Solid Polymer Matrices
    TANG Guo-Qing, SHANG Xiao-Ming, ZHANG Gui-Lan, DU Rong-Jian, CHEN Wen-Ju
    1996, 17(6):  906-910. 
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    This paper first reports the spectroscopy and the properties of excited-state intramolecular proton transfer(ESIPT) of 2-(2'-hydroxy phenyl) benzoxazole(HBO) in some solid polymer matrices and the matix effects on them,The results show that;(1) The properties of ESIPTand spectra of HBOin the non-polar and weak polar polymer matrices would not be modified compared with those in the solution systems.The matrices,on the other hand,could improve the quantum yield of ESIPTfluorescence,(2) The polymer matrices with strong H-bonding activity and polarity can modify the spectra and the ESIPTefficiency of HBOdue to the formation of H-bonding complex between HBOand the matrix,which,however,could be eliminated effectively by using a special micelle method to isolate HBOfrom the matrices.(3) Thermodynamic equilibrium of the ground state rotamers of HBOin the solid polymer matrices seems to have a tendency which is unfavourable to the formation of the rotamer Ⅰ and Ⅲ.
    Studies on Solid State Photochemical Reaction of the Complexes of Lewis Acid and Chalcones
    LI Xiao-Liu, WANG Yong-Mei, MENG Ji-Ben
    1996, 17(6):  911-913. 
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    The solid state photodimerization reaction of three chalcones was carried out using the Lewis aicd complex to control the crystal structure of Chalcones,It was shown that the Chalcone in the complex existed in the enolic form which was inert to photodimmerize if there were donating-electron groups on phenyl ring.
    The Synthesis and Anti-lipid Peroxidation Activity of Amino Acid Derivatives of Ebselen
    XIAO Ying-Xin, LIU Xiu-Fang, XU Han-Sheng, SUN Shi-Yong, XU Bo
    1996, 17(6):  914-916. 
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    Amino acid was used as a carrier of the active molecule──ebselen,which mimicked the properties of GSH-Px and was known as an anti-inflammatory drug.Eiht ebselen derivatives with amino acdethyl esters attached to the p-position of 2-phenyl moiety were prepared.2-(4'- Carboxylphenyl)-1,2-benzisoselenazol-3(2H)-one(1) was used as the intermediate prepared in good yield by cyclization of 2-chloroselenobenzoyl chloride with 4-amino benzoic acid in the presence of Et3N.Then l was treated with p-toluenesulfonates of amino acid ethyl ester,and the target compounds were obtained by further purification,Effects of compounds 1,2,3,4 as well as ebselen on Fe 2+/cysteine-induced rat liver microsomal peroxidation were studied.Their IC50 were 30,22.7,17.7,22.2 and 24μmol·L-1,respectively.
    Studies on the Kinetics of the Reaction of C60 and C70 with Benzoyl Peroxide
    HU Bo, XUE Wan-Hua, ZHANG Fa-Yi, SHANG Zhen-Feng, MA Ke-Qin, ZANG Ya-Ru, ZHAO Xue-Zhuang
    1996, 17(6):  917-919. 
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    The kinetics of the reaction of C60 and C70 with benzoyl peroxide is studied.The results show that the reaction is first order against fullerenes and the rate constants at 342.2K,348.2K, 353.2 Kand 358.2 Kwere calculated and they are in agreement with experimental results.The rate constant of C70 is greater than that of C60 and this indicated that C70is more actived than C60.The activation energies are 9.275×104J/mol and 8.438×104J/mol for C60 and C70 respectively.
    Photochemical Synthesis of 1,2-Dihydro-3H-indol-3-ones
    LING Ke-Qing
    1996, 17(6):  920-922. 
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    Disubstituted and 1,2,2-trisubstituted 1,2-dihydro-3H-indol-3-ones(3-6)have been synthesized via singlet oxygen reaction of 2-phenylindole(1a) and 1-methyl-2-phenylindole(1b) in methanol,followed by acid-catalyzed nucleophilic substitution of the resulting oxidation products(2) in good yields.
    Research on Synthesis and Biological Activity of New Sydnone Compounds
    LI Zhen-Ming, FAN Chuan-Wen, WANG Su-Hua
    1996, 17(6):  923-924. 
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    Sydnones are typical meso-ionic compounds.Twelve new sydnone compoundswere reported in this paper,Their structures were confirmed by elementary analysis and 1H NMRand their biological activity was investigated.
    A Theoretical Study of the Structures and Electronic Spectra for N-Ethylphenotiazine and Its Radical Cations
    FENG Ji-Kang, GAO Xiao-Shun, JIA Qing, LIU You-Cheng, SUN Chia-Chung
    1996, 17(6):  925-929. 
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    The geometries of N-ethylphenotiazine and its radical cation have been optimized by using INDOseries methods,The configuration of neutral molecule is one of folded butterfly and that of the radical cation is planar.On the basis of optimized geometries,the charge densities,spin density,bond orders and electronic spectra of above molecule and cation have been calculated.The spectra have been assigned theoretically and the red shift of spectral band from molecule to cation has been discussed.All calculated results are in good agreement with experimental ones.
    Theoretical Investigation on P12(D3d) Cluster
    HUANG Xu-Ri, FENG Jian-Nan, LI Ze-Sheng, SUN Chia-Chung, ZHANG Gang
    1996, 17(6):  930-932. 
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    The structure of P12(D3d) is optimized under 6-31G* basis set by using Gaussian 92 program,the relative energy of 3P4(Td)→P12(D3d),△E=EP12(D3d)-3EP4(Td)=-79.844kJ/mol, is investigated.The result calculated by Marco was △E=EP12(D3d)-3EP4(Td)=-32kJ/mol by using TUBOMOLEprogram SVPbasis set.Comparing with Marco's result,it is shown that the structure of P12(D3d) is more stable in thermochemistry,the optimized bond lengths between phosphorous atoms are closer to the experimental values,Furthermore,vibrational frequencies of the cluster of P12(D3d) are also calculated.The results indicate that the D3d structure of the cluster of P12 is a stable point on potential surface.
    The Mechanism of Adsorption of Nonionic Surfactants on CAB-O-SIL and the Effects of Surface Micellization on the Stability of Silica Suspension
    QIAN Jian-Gang, WU Jin-Ping, GU Ti-Ren
    1996, 17(6):  933-938. 
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    The adsorption isotherms of Triton X-100(TX 100) on a flamehydrolyzed silica (CAB-O-SIL) from aqueous solutions and from sodium chloride(1.0 mol/L) at 290.7K and 304.2 Khave been determined.The results show that the adsorption increases with increasing temperature and salinity.Based on the theory of surfactant adsorption we proposed previously,the equilibrium constant of surface micellization(K),surface micelle aggregation number(nsm),surface micelle concentration(smc) and the standard thermodynamics functions(△G0am, △S0am,△H0am of surface micellization are calculated.The results show the value of nsm increases with increasing temperature,In addition,similar to the micellization in bulk solution,the surface micellization is also an entropy-driven process.The effects of TX100(with or without 1.0 mol/Lsodium chloride) on the aggregative stability of silica suspension have also been investigated.In the low concentration range of TX 100, the stability of suspension increases with increasing concentration of TX 100.Above the surface micelle concentration(smc) of TX 100, the stability of suspension decreases with increasing concentration of TX 100.However if the concentration approaching to the cmc of TX 100,the stability of suspension increases again,The addition of sodium chloride enhances the surface micelle formation and results in a depression of stability of suspension,Based on the adsorp tion isotherms of TX 100,a model concerning surface micellization is proposed to explain the above experimental results reasonably.
    Studies on Preparation,Characterization of Cobalt(Ⅱ) Phenanthroline and 8-Hydroxyquinoline Complexes/Y Zeolite,and Catalytic Hydroxylation of Phenol
    QI Xmg-Yi, WANG Guo-Jia, YIE Xing-Kai, WU Yue
    1996, 17(6):  939-943. 
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    Cobal(Ⅱ) phenanthroline and 8-hydroxyquinoline complexes/Yzeolite,denoted as CoPhen/Yand CoOx/Yrespectively,were prepared.The formation of the metal complexes mentioned above within the cages of Yzeolite and their crystal structures were determined by elementary analyses,TG-DTA,diffuse reflectance UV-Vis,SEM,BETand XRDmethods.The influence of experimental parameters upon phenol conversion and product selectivities was investigated as well.
    129Xe NMR Studies on LaNaY Zeolites with Various Lanthanum Contents
    WEI Zhong, WANG Xing-Long, LI Quan-Zhi, XUE Zhi-Yuan, MAO Xue-Wen, TANG Rong-Rong, SHAO Jing-Hao, YUAN Suo-Liang
    1996, 17(6):  944-948. 
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    The location of cations in LaNaYzeolites with various lanthanum contents(from 1.5 to 18.7 La ions/u.c.) has been studied by 129Xe NMR technique.It is found that all LaNaY samples pretreated at 350℃ in vacuum,even with low lanthanum content,have some lanthanum cations remaining in supercages,and the amount of cations in supercages depends on the total content of lanthanum in zeolites,When the lanthanum content exceeds 8La ions/u.c.,couples of lanthanum cations appear in sodalites(β cages),and irreversibly form bridging lanthanum oxide or oxyhydroxide species at temperature 350℃,but below this content,the reaction doesn't occur,and lanthanum cations located in different sodalites,respectively,Usually,Na129 cations in Yzeolite as a whole are considered as being independent of the chemical shift of Xe atoms,but according to our result of 129Xe NMR,the unlocated Na129cations in supercage have an interaction with Xe and affect the chemical shift of xenon.
    Effect of Alcohol and Salt on Solubilization of Water in Reverse Micelles Formed by Dodecylammonium Propionate in Carbon Tetrachloride
    GUO Hong, HUANG Wen, GU Ti-Ren
    1996, 17(6):  949-952. 
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    The effect of alcohols with different chain lengths and sodium chloride on the solubilization of water of the dodecylammonium propionate(DAP) reverse micelles in carbon tetrachloride has been investigated.At fixed DAPconcentration,the water solubilization vs.ROHconcentration curves pass through a maximum value,For the alcohols studied in this work,the longer the hydrocarbon chain of an alcohol,the larger the water solubilization.Moreover,at fixed DAPconcentration and ROHconcentration (at which the water solubilization curve shows maximum) the addition of sodium chloride will decrease the solubilization of aqueous solution.According to the consideration of the polarity of the organic phases,the distribution of the surfactant between the organic phase and interfacial region and the salting effect,the results have been explained reasonably.
    Immobilized Catalase with Microcapsules
    WANG Yu-Jie, LIU Chin-Biao, BAI Guang-Yue, CHU Ying, WANG Feng-Ping, MA Zhan-Fang, ZHANG He-Zhe
    1996, 17(6):  953-956. 
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    Catalase was microencapsulated with ethyl cellulose as a film material by a method of drying in liquid.It was investigated that the immobilized catalase was affected by temperature and pHand inhibited by hydrogen peroxide.The available temperature and pHranges of the microencapsulated catalase owing to the protection of ethyl cellulose film and the buffer action of gelatine and phosphoric acid separately,and the inhibition, because of the presence of gelatine,are enlarged clearly.
    Studies of Molecular Conformation of (E)-2-Methyl-1,3-pentadiene with Vibrational Spectra
    ZHAO Bing, XU Wei-Qing, LIU Ju-Zheng
    1996, 17(6):  957-960. 
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    Vibrational spectra of (E)-2-methyl-1,3-pentadiene have been recorded over a range of temperature for three phases, and completely assigned.The investigation of a pair bands 658 and 686 cm-1 by dynamic FTIRspectra shows that the compound existed as a mixture of s-trans and s-cis conformers of single bonding rotation.By means of observed changes of the peak intensities of FTIRspectra with variable temperature, the values of ΔH0 and ΔS0 of the isomer inversion have been deduced to be 5.36 kJ/mol and 7.66 J/mol· Krespectively.
    NO Reduction by Surface Oxygen-Containing Groups on Active Carbons
    GAO Zhi-Ming, WU Yue, TIAN Mei
    1996, 17(6):  961-964. 
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    Four kinds of active carbons(AC) were investigated,which were made of coconut shell(CS),hawthorn nut (HN), mountain peach nut(PN)and coal(C),respectively.Elementary analyses showed that HNACand PNACwere rich in oxygen-containing,however it was few in CSACand CAC.Oxygen-containing groups,especially carboxyl groups on active carbons were found to have a great influence on the reducibilities of active carbons.And yet,the carboxyl groups were abundant on HNAC and PNAC,but scarce on CSACand CACillustrated by Boehm's titration and NH3-TPD,Meanwhile,HNAC and PNAC also exhibited much better performance on NOreduction than CSACand CAC.This revealed that oxygencontaining groups indeed acted as the reactive centers of NOreduction,especially —COO— was the most important.The reaction mechanism of NOreduction was thus proposed.
    Preparation and Properties of Highly Active Electrorheological Fluid Based on Polyiline
    GUAN Jian-Guo, XIE Hong-Quan, GUO Jun-Shi
    1996, 17(6):  965-967. 
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    Dedoped polyaniline(PAn) particles with special core-shell structure were synthesized by chemical oxidation polymerization of aniline(An) through dropping An into oxidant solution with different charging sequences,and partially dedoped with concentrated ammonia water,then mixed with chlorinated paraffin oil to form anhydrous electrorheological fluid (ERF).The ERFhas a large static yield stress of 16.3 kPa and concomitant low current density of 2.67 μA/cm2 under direct current electric field strength of 2.8 kV/mm.
    Studies on Chitosan-Fibroin Blend Membranes(Ⅱ)──The pH and Ion Sensitivities of Semi-IPN Membranes
    CHEN Xin, LI Wen-Jun, ZHONG Wei, GE Chang-Jie, WANG Han-Fu, YU Tong-Yin
    1996, 17(6):  968-972. 
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    The chitosan-fibroin semi-IPNmembranes have been prepared and the pHand ion sensitivities as well as the reversibility of swelling between the different pHbuffer solutions have been studied.The results showed that the water swelling ratios of the semi-IPNmembranes increased dramatically when pH <3.3 and the semi-IPNmembrane showed better pHsensitivity than the uncrosslinked chitosan fibroin blend membrane.It also showed that the appearance of the maximum swelling ratio of semi-IPN membranes at pH=2 was related to the composition of membrane and the content of crosslinking agent.In the meantime,the membrane could swell and contract when pHwas alternately changed and the reversibility was rather good.In addition,the water swelling ratio was larger in the trivalent ion solution than those in the monovalent and the bivalent ion solutions with the same ionic strength.
    Studies on Liquid Crystalline Behavior of Chitosan
    DONG Yan-Ming, ZHANG Jing
    1996, 17(6):  973-977. 
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    The lyotropic liquid crystalline behavior of a natural macromolecule-chitosan was studied using polarized microscopy,average refractive index method and FTIR.The critical concentrations of chitosan in solvents of dichloroacetic acid,formic acid,acrylic acid and 36% acetic acid were all 8% (percentage by volume) or 4%～6%(percentage by weight).These experimental values are consistent with the calculated value deduced according to Flory theory.These low critical concentration values also imply that the chain rigidity of chitosan is larger than that of cellulosic chain.
    Relationship Between Molecular Structure and Its Heat Properties for Rigid Chain Polymers of Poly(aryl ether ketone sulphone)s
    KE Yang-Chuan, ZHENG Yu-Bin, WU Zhong-Wen, ZHANG Shan-Ju, NA Hui, WANG Jun-Zuo, JI Xiang-Ling
    1996, 17(6):  978-982. 
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    The full optimization structure of model compound ArOArCOArArCOArOAr is presented with average dihedral angle of 37.5°,Based on this ,the molecular structure is related to the melting point and glass transition for poly (aryl ether ketone) s and poly(arylether sulphone) s family with rigid molecular chain, The obtained relationship between them is well extended to predict the heat properties of the new family of aromatic homopolymers.
    Studies on the New Type of Affinity Adsorbent(Ⅰ)──Preparation and Immobilization of Ligand
    GUO Xian-Quan, CHEN Zheng, CHEN You-An, HE Bing-Lin, YANG Yan
    1996, 17(6):  983-986. 
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    This paper describes the application of vinyl acetate and trially isocyanurate copolymer(VT) as support,which was then saponified,activated,and amino acid was immobilized on to the adsorbent.The effect of different reaction conditions was investigated.
    The Phenomena of Tensile Acoustic Emission of PS,POM,ABS and PC
    ZU Ziao-Tao, WU Ji-Hong, LIU Min-Zhi
    1996, 17(6):  987-990. 
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    The tensile acoustic emission(AE) phenomena of PS,POM,ABSand PCwere studied.It was found that AEsignals are mainly produced before yielding and during fracture.That illustrated the production of AEsignals of polymers is mainly due to the unbinding of the molecular chains,the slip of crystalline,the subcritical crack propagation and the fracture of molecular chains.Crazing in a large scale may be a source of AEsignals,The tensile strain rate,plastics'construct and the different yielding processes have great influence on the law of tensile acoustic emission of plastics
    Analysis of Polyolefin Alloy with TREF
    XU Jun-Ting, FENG Lin-Xian, YANG Shi-Lin
    1996, 17(6):  991-992. 
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    Apolyolefin alloy sample was fractionated by using temperature rising elution fractionation(TREF) technique.From the TREFcurve it was found that this sample was composed of three components,Some fractions were characterized by 13C NMRand DSC.The results show that these three components are ethylene-propylene random copolymer,ethylene-propylene block copolymer and propylene homopolymer.
    Studies on the Relation Between Critical Concentration and Solubility Parameter of a Lyotropic Liquid Crystalline Polymer Hydroxypropyl Methyl Cellulose
    DONG Yan-Ming, HONG Zhao-Zhao
    1996, 17(6):  993-995. 
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    Critical concentration cp* of lyotropic liquid crystalline hydroxypropyl methyl cellulose(HPMC) in twelve solvents was determined using both Abbe refractometer and polarized microscopy.cp* is related not only to the acidity of solvents,but also to the solubility parameter δof solvents,There was a general tendency that the more the δof solvents closed to that of HPMC,the lower the cp* was,although the experimental points were somewhat disperse.When the sort of solvents was limited to a simple series such as acetic acid,chloroacetic acid,dichloroacetic acid and trichloroacetic acid,a good linear relation was found between cp* and δ.Alower chain rigidity of HPMC was also evaluated by the persistence length value of Kuhn chain theoretically deduced from critical concentration.
    Textures of the Coagulated Films of Presheared PBZT Solution
    DING Jian-Dong, HU Yu-Hong, YANG Yu-Liang
    1996, 17(6):  996-997. 
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    The semi-concentrated PBZT/MSA solution was presheared and then coagulated in water,The film was observed with polarized optical microscopy and small angle light scattering,and taken on different textures,for example,droplet,inclined cone,inclined fiber,etc,Some questions were,therefore,open,such as the formation mechanism of the supramolecular structures associated with the textures,the shear-induced molecular orientation,determination of the degrees of both crystallization and liquid crystallization.
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