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Table of Content

    24 April 2002, Volume 23 Issue 4
    Articles
    Preparation and Electrochemical Characteristics ofa New Type Mg-based Hydrogen Storage Alloys
    YUAN Hua-Tang, LI Qiu-Di, WANG Yi-Jing, SONG He-Nan, FENG Yan
    2002, 23(4):  517-520. 
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    The Mg-based hydrogen storage alloys Mg1.5Al0.5-xNiVx(x= 0, 0.1, 0.2, 0.3,0.4) were successfully synthesized by means of a diffusion method (MD).The structure of these alloys were examined by X-ray diffraction.Anew phase was found in the alloys.Its chemical formula is Mg3AlNi2.Further studies reveal that the new phase has excellent electrochemical properties.The discharge capacity of Mg1.5Al0.5-xNiVx alloys increases owing to Vaddition and reaches the highest capacity of 333 mA·h·g-1 (50 mA·g-1, -0.5 Vvs.Hg/HgO) without any treatment.The improvement of cycle life was ascribed to the partial substitution of Al for Mg in the alloy.
    Hydrothermal Synthesis, Crystal Structure and Properties ofSupermolecular Compound (bipyH2)2(H2P2Mo5O23)·H2O
    ZHAO Shi-Long, ZHANG Han-Hui, HUANG Chang-Cang
    2002, 23(4):  521-525. 
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    Anovel molybdophosphate supermolecular compound (bipyH2)2(H2P2Mo5O23)·H2O has been synthesized by hydrothermal method and characterized by crystal X-ray structure analysis, IR spectrum, Raman spectrum, UV-Vis DRIS spectrum, fluorescence spectrum and CV.The crystal belongs to mono-clinic system with a space group P21/c, a=l.67951(7) nm, b=1.15193(4) nm, c=1.88908(8) nm, β= 108.335(1)°,V=3.4692(2) nm3, Z = 4, Dc = 2.382 g/cm3, F(000) =2408, μ=1.951mm-1, R=0.0244, Rw = 0.0721.The heteropoly anion[H2P2Mo5O23]4- and protonated 4,4'-bipy are connected to a supermolecular compound by hydrogen bonds; and the anions contain five MoO6 octahedra and two PO4 tetrahedron; Mo, Patoms show a distorted pentagonal bipyramidal configuration, and the heteropoly anions are connected to a infinite planar structure with the protonated 4,4'-bipy.
    Preparation of Rare Earth Ion Induced Conformation-specificAnti-calmodulin Monoclonal Antibody
    LI Wei-Guo, QI Chao, Du Li, LIU Zi, ZHAO Da-Qing
    2002, 23(4):  526-529. 
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    Monoclonal antibody technique was employed to detect the conformational change of calmodulin induced by metal ions.Bovine calmodulin was firstly modified by 2,4-dinitrofluorobenzene to improve its immunogenicity, then, the derived protein was saturated with trivalent europium ions and injected to Balb/c mice as antigen.After four times of immunization, a corresponding antibody was detected and its titer in serum was determined as 1:12000.By fusing of the spleen cells with hybridoma cells, a europium induced conformation-specific anti-calmodulin monoclonal antibody cell strain named as 2C3 was produced successfully.The molecular recognition ability of antibody to apocalmodulin and holocalmodulin showed a significant difference, indicating that this antibody could be applied to the studies of different effects of metal ions on the conformational change of calmodulin and its interaction with target molecules.
    Studies on Enzymological Properties of Antibody Elicited bymeso-Tetra(α, α, α, α-O-phenylacetyl benzene)porphyrin
    QI Chao, DING Lan, DING Tian-Bing, LIU Zhi-Qiang, ZHANG Yu-Jing, LIU Li-Yan, ZHAO Da-Qing
    2002, 23(4):  530-534. 
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    meso-Tetra(α,α,α,α-O-phenylacetyl benzene)porphyrin was used as a complete antigen to elicit monoclonal antibody 1F2 through the immunization and cell fusion techniques.McAb1F2 obtained was demonstrated very pure by HPLCand MALDI/TOFMS.The retention time of McAb1F2 was 2.63 min.The subtype of McAb1F2 was IgG2a.The relative molecular weight was 156678.8.When the McAb1F2-porphyrin was formed, the maximal absorption of the porphyrin soret region had a redshift from 408 to 416 nm and hyperchromical effect, showing that the antigen-antibody combination was rigid and intense , and the abzyme constancy was high.But compared with HRP, the activity of the abzyme was only 4.6875 U/mg and 1.899% of that of HRP.Its Km was 20.29 mmol/L, kcat 396.82 min-1, kcat/Km 1.9557×104 L·mol-1·min-1.
    Hydrothermal Synthesis and Crystal Structure of a Three-dimensionalOpen-framework Compound, {[Cu(1,2-pn)-2]4[V18O42(H2O)]}n·8nH2O
    LIN Bi-Zhou, LIU Shi-Xiong
    2002, 23(4):  535-537. 
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    The hydrothermal reaction of V2O5, Cu(CH3COO)2·H2O, TMAOH and 1,2-diaminopropane gave a novel three-dimensional framework material, {[Cu(1,2-pn)2]4[V18O42(H2O)]}n ·8nH2O, which was constructed from the mixed-valence {V18O42(H2O)} clusters interconnected through {Cu(1,2-pn)2} complex groups.{[Cu(1,2-pn)2]4[V18O42(H2O)]}n ·8nH2O was characterized by IR, TGA and single-crystal X-ray diffraction.It crystallizes in tetragonal space group P4/nnc with a=1.5107(2) nm, c = 1.8645(4) nm, Dc = 2.028 g/cm3, Z = 2, R1= 0.0631, wR2 = 0.1538.
    A Relationship Between Adsorption Heat and Structure ofAdsorbate Molecule in NaX Zeolite Molecular Sieves
    LI Bao-Zong, GUO Yong-Min, PANG Wen-Qin
    2002, 23(4):  538-540. 
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    In this paper, the molecular graphics techniques and the ab initio molecular orbital STO-3Gcal-culations were adopted to study the molecular sizes and electronic structures of 24 molecules as adsorbate inthe NaX zeolite.Further more, the interaction energies of various molecules with Na+ were studied by abinitio calculations.The results show that there exists a significant correlation between the adsorption heatand molecular polarizability of the alkane(R= 0.998, F= 831.155, S=1.241, N= 6).Meanwhile signif-icant multivariate correlation was found between the adsorption heat and interaction energies of variousmolecules with Na+, molecular Van der Waals volumes and lowest unoccupied orbital energies, in which Na+ takes an important role as the intermediate.
    Studies on the Electrochemical Behavior of Methotrexate and Its Applicationat Co/GC Ion Implantation Modified Electrode
    SUN Zi-Jie, HU Jin-Bo, QIAN Yong-Gui, LU Yi-Qiang, LI Qi-Long
    2002, 23(4):  541-545. 
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    With Co/GCion implantation modified electrode as the working electrode, in 0.1mol/L HAc-NaAc (pH= 4.96) buffer solution, a sensitive reductive wave of methotrexate was obtained by linear sweepvoltammetry.The peak potential was -0.95 V(vs.SCE).The peak current was proportional to the con-centration of methotrexate in the range of 2.2 × 10-7~8.8 × 10-6 mol/Lwith the detection limit of 1.1×10-8 mol/L.The behavior of the reduction wave was studied and applied to the determination ofmethotrexate in tablets.The reduction process was irreversible with adsorption, The composition anddepth distribution of elements on the surface of the Co/GCE were determined by Auger electron spec-troscopy and X-ray photoelectron spectroscopy.The experiments showed that Co was surely implanted in-to the surface of glassy carbon.The implanted Co catalyzed the reduction of methotrexate.
    The Determination of Reaction Orders and Rate Constantsby Target-Testing Factor Analysis
    ZHU Zhong-Liang, XIA Jun, MI Shou-Gang, LI Tong-Hua
    2002, 23(4):  546-551. 
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    Target-Testing Factor Analysis(TTFA), combined with Numeric Genetic Algorithm(NGA),is adopted to solve the kinetic-spectral data matrix obtained on-line during chemical reactions.The methodis advantageous owing to that it can provide information on rate constants and the reaction orders of chemi-cal reactions as well as the spectrum of species in the reaction, without previous knowledge of the kineticmodel of the reaction and the pure spectrum of species.Furthermore, an approximate algorithm is pro-posed to compute the kinetic spectrum of each species, thus making the method effective as well for reac-tions with fractional orders.This method is employed to solve the synthetic data for systems that are incompliance with the two-step consecutive reaction model and where the species all absorb or one of themdoesn't, and its effectiveness proved.The method is also applied to the analysis of practical reaction sys-tems such as alkaline hydrolysis of dimethyl phthalate and electrodegradation of sunset yellow aqueous solu-tion, and satisfactory results are obtained.
    High Performance Liquid Chromatographic Analysis of Catecholaminein the Microdialysate from Rat Brain
    CHANG Li-Wen, XU Gui-Yun, HAN Hui-Wan, CHANG Xi-Yan, ZHAO Zhuo
    2002, 23(4):  552-554. 
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    A method for determination of catecholamine and related metabolite in the microdialysate fromrat brain by HPLC With pulsed amperometric detection was described.The optimum condition of chro-matographic separation and pulsed amperometri detection were studied.Sampling was carried out by mi-crodialysis technique from rat brain.Acomparison of epinephrine(E) content in microdialysates from ratbrain at various event was made.The detection limit of the method is 25 μg/L for epinephrine.
    A Simple and Fast Method to Determine Competitive Isotherms- The Frontal Velocity Analysis Method
    YANG Geng-Liang, SUN Su-Fang, LIU Hai-Yan, WANG De-Xian, CHEN Yi, SUN Han-Wen
    2002, 23(4):  555-558. 
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    Asimple and fast method, the frontal velocity analysis method was used to determine the com-petitive isotherms for p-dihydroxy-benzene and resorcinol on ODS-silica with volume ratio 20: 80methanol-water as the mobile phase.The data obtained from it are fitted to competitive-Langmulrisotherms, and the best parameters are obtained.Meanwhile, a classic method, the rectangular pulsemethod was also used to determine the competitive isotherms for the same system under the same condi-tions.The results obtained show that the competitive isotherms obtained from the frontal velocity analysismethod and the rectangular pulse method are in well agreement.This shows that the simpler and easiermethod——the frontal velocity analysis can be used to determine competitive isotherms with the same ac-curacy as the classic method.
    The Algorithm on Automated Aromaticity Perception of Molecules
    HAO Jun-Feng, XU Lu
    2002, 23(4):  559-563. 
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    It is important to detect the aromaticity of structures during the process of structure elucidationand output.In this paper, an alogrithm was proposed to detect the aromaticity of structures by the use ofalgorithm on ring identification.The results show that it could be used to identify most of the aromaticstructure.It have been used as constraints of Expert System on Elucidation Structure of Organic Com-pounds(ESESOC) and a good result has been achieved.
    Terbium Sensitized Chemiluminescence of Gatifloxacin and Its Application
    LIAN Ning, ZHAO Hui-Chun, SUN Chun-Yan, JIN Lin-Pei, ZHANG Zhong-Lun, ZHENG Yan-Zhen
    2002, 23(4):  564-566. 
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    A selective and sensitbe sensitized chemiluminescence (CL) method for the determination ofGatifloxacin(GFLX) is described.The method is based on Tb3+ sensitized chemiluminescence of the Tb3+-GFLX-Ce(Ⅳ)-SO32- system since CLfor the binary Ce(Ⅳ)-SO32- system is weak, while CL is enhanced when Tb3+-GFLX is added to the Ce(Ⅳ)-SO32- system.The possible mechanism of the CLreaction maybe that Ce(Ⅳ) can oxidize HSO3- to a hydrogen-sulfite radical HSO3, then HSO3 radicals produce S2O62-,S2O62- will form the excited intermediate product SO2. The energy of SO2 is mainly transferred to Tb3+-GFLX, and the CLspectrum shows a characteristic emission of Tb3+.The re1ationship between the CLin-tensity and the concentration of GFLXis linear in the range of 2.0 × 10-8-1.0×10-6 mol/L, and the de-tection limit is 3.5 × 10-9 mol/L.The relative standard deviation(RSD) for 11 independent determinationsof 1.0×10-7 mol/L GFLX was 3.2%.Common excipient starch was used in pharmaceutical preparationand most of metal ions do not interfere with the determination of GFLX.GFLXin urine can be analyzeddirectly after appropriate dilution of the samples, and the analytical result is satisfactory.
    A Novel Microchip-based Capillary Electrophoresis SystemWith Electrochemical Detection and ItsApplication to the Analysis of Neurotransmitters
    ZENG Yong, CHEN Hong, PANG Dai-Wen, WANG Zhong-Li, CHENG Jie-Ke
    2002, 23(4):  567-569. 
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    A novel microchip-based capillary electrophoresis system, based on the micro-electrode end-col-umn electrochemical detection, is described.Afixed guide tube was aligned accurately with the outlet ofthe separation channel to achieve the proper and reproducible alignment of microelectrode with the channel.Such a design permits easy and rapid replacement of different material microelectrodes or modified elec-trodes, obviating the disadvantages of permanent attachment of the detector.Using the homemade 7 μmcarbon-fiber microdisk electrodes and 30 μm Pt microdisk electrodes, a performance of separating neuro-transmitters, with good precision and submicromolar detection limits, demonstrated the versatility, sim-plicity, low-cost and high-sensitivity advantages of this new detector.
    Temperature-constrained Cascade Correlation Network andIts Application to Bacteria Identification
    ZHANG Zhuo-Yong, Aaron Urbas, Peter de B Harrington, Kent J. Voorhees, Jon Rees
    2002, 23(4):  570-572. 
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    The theoretical basis of temperature constrained cascade correlation network(TCCCN) was in-troduced briefly.The TCCCNmodels were used to identify various bacteria from their matrix-assistedlaser desorption/ionization time-of-flight mass spectrometric (MALDI-TOF-MS) data.The identificationof eight different bacteria and the bacteria identification based on different culture time have been dis-cussed.The results show that the TCCCNcould produce robust and feature-oriented models for bacteria i-dentification based on MALDI-TOF-MS.However, mis-identification may occur for some bacteria sam-ples due to variation in cell biology under environmental conditions.
    Determination of Kinetic Parameter of Catalytic Reaction byNear Field Laser Thermal Lens Spectrometry
    HAN Quan, YAN Hong-Tao
    2002, 23(4):  573-575. 
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    A new method for the determination of kinetic parameter of catalytic reaction by near field laserthermal lens spectrometry is proposed in this paper.The parameters of the kinetic reaction in which traceiridium catalyzed oxidation of nile blue Aby potassium periodate in a weak acidic medium is determinatedsuccessfully by near field laser thermal lens spectrometry.The catalytic reaction is first-order in Ir(Ⅳ),nile blue Aand KIO4, and the apparent activation energy of the catalytic reaction is 70.9 kJ/mol.
    Synthesis and Properties of New Thiadiazole Liquid CrystallineCompounds with Amide Central Linkages
    SHANG Yong-Jia, LI Mao-Guo, LU Wan-Fang, WANG Yan-Guang
    2002, 23(4):  576-580. 
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    Sixteen 2, 5-bisphenyl-1, 3, 4-thiadiazoles with amide central linkages were synthesized.Theirchemical structures were analyzed by IR and 1H NMR spectrometry.The liquid crystalline properties weredetermined by POMand DSC.The results show that they are all thermally stability liquid crystals andhave higher phase transition temperatures and wide phase transition temperature ranges.The paper indi-cated that the amide central linkages are more conductive to smectic phase.The effect of the carbon atomnumber of terminal group on mesomorphic properties was discussed.
    Synthesis and X-ray Diffraction Crystal Structure ofBis(trialkyltin) 1, 1'-ferrocene Dicarboxylates
    MU Zhao-De, SUN Li-Juan, LUO Ning, XIE Qing-Lan
    2002, 23(4):  581-584. 
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    Thirteen new bis(trialkyl)tin 1, 1' -ferrocene dicarboxylates were synthesised and characterizedby IR, 1H NMR, MSand elemental analysis.The X-ray diffraction crystal structure ofMeCy2SnO2CC5H4FeC5H4CO2SnCy2Me was determined.The results show that the Sn atom is in slighlydistorted trigonal-bipyrimidal environment.The compound has a linear polymer's structure.
    Synthesis of Hexahydro-1H-1,4-diazepine Analogues Carrying the Segment of(1-Arylacetamide-2-tertiary amide) Ethane and Their Analgesic Effects
    SHEN Jing-Shan, LEI Li-Jun, LI Jian-Feng, JI Ru-Yun
    2002, 23(4):  585-590. 
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    In order to get some selective κ-opioid receptor agonists, which can relieve pain while lackingserious side effects, 16 target compounds of hexahydro-1H-1, 4-diazepine analogues carrying the segmentof (1-arylacetamide-2-tertiary amide) ethane were synthesized through single amidation and amidation ofthe basic modified structures of compounds 1-3, 2-(5-) substituted hexahydro-1H-1, 4-diazepine.Thestructures of these products were characterized by IR, EIMS, elementary analysis and 1H NMR.All thetarget compounds were screened in vitro in the guinea pig ileum(GPI) for their receptor affinities.The pre-liminary pharmacology tests indicated that these compounds showed a certain agonist activity(presented inthe item of inhibition rate) respectively at 5 × 10-6mol/Llevel and the IC50 values(μmol/L) of compounds5, 7 were achieved.The antinociceptive potencies of the compounds with a higher potency(compounds 5,13, 22, 23) in the GPIstudy were further tested their in the mouse abdominal constriction model and their ED50 values(mg/kg, s.c.) were also obtained.
    A Novel Synthesis Method of 1-Aza-2,8-dioxabicyclo[3.3.0] octane Derivatives
    JIAN Tian-Ying, WANG Zhao-Yang, WANG Jian-Ping, CHEN Qing-Hua
    2002, 23(4):  591-594. 
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    A series of 1-aza-2, 8-dioxabicyclo[3.3.0] octanes containing multiple functional groups weresynthesized though [3+2] cycloaddition reaction of 4-substituted phenyl-3, 5-bis (methoxycarbonyl)-2-isooxazoline-N-oxides with ethyl acrylate as dipolarphile.The reaction underwent under a mild conditionand offered the products with higher yields (50%-93%).The structures of the compounds synthesizedwere confirmed by elemental analyses, 1H NMR, 13C NMR, IR and MS.
    Ansa-Metallocene Complexes(V)- Synthesis and Application in Olefin Polymerization ofGerma-bridged Indenyl and Substituted Indenyl Zirconium Complexes
    XU Shan-Sheng, TIAN Gong-Lu, WANG Bai-Quan, ZHOU Xiu-Zhong, LIANG Bo, ZHAO Liang
    2002, 23(4):  595-599. 
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    Germa-bridged indenyl and substituted indenyl ligands react with n-butyl lithium and ZrCl4 togive Germa-bridged indenyl and substituted indenyl zirconium complexes Me,Ge (2-R1-4-R2-Ind)2 ZrCl2[R1=R2=H(1); R1=Me, R2 =H(2);R1=Me, R2=Ph(3) ].Compounds 1-3 are mixture of rac andmeso isomers.After fractional crystallization pure rac-1, rac-2 and meso-3 were isolated.Compounds 1-3were characterized by 1H NMR and elemental analyses and used for the polymerization of ethylene andpropylene in the presence of methyl aluminoxane (MAO).The molecular weight distribution of thepolyethylene obtained with compounds 1-3 is slightly broader than that with general metallocenes.A-mong them, the molecular weight distribution of the polyethylene obtained with the mixture of rac-3 andmeso-3 is much broader due to the two unequal catalytic active centers in the system.Compounds rac-1 andrac-2 catalyzed propylene polymerization to give isotactic polypropylene.
    Structure Elucidation of a New Saponin from Tribulus Terrestris L. Using High-field Gradient NMR Techniques
    TU Guang-Zhong, MA Li-Bin, LI Xi-Lai, AN Dong-Ge, SUN Wen-Ji, GUO Zun-Wu, GAO Jin
    2002, 23(4):  600-604. 
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    A new saponin was isolated from Thoulus terrestris L..By means of a series of 2DgradientNMRtechniques, including 1D gradient selective TOCSYand GEOSY, 2D gradient-COSY, NOESY,TOCSY, HSQC, HSQC-TOCSY, the structure of the saponin was elucidated as 26-O-β-D-glucopyra-nosyl-22-methoxy-furostane-3-O-{β-D-xyloPyranosyl-(1→3)-[β-D-xylopyranosyl-(1→2)-β-D-glucopy-ranosyl-(1→4)}-[α-L-rhamnopyranosyl-(1→2)]-β-D-galactopyranoside.
    Isolation and Characterization of Toxin Polypeptides fromSea Anemone Actinia cari
    ZHUO Ru-Peng, FU Hong-Zheng, LI Jun, ZHANG Li-He, ZHONG Chong-Bo, WANG Xiao-Liang, LIN Wen-Han
    2002, 23(4):  605-609. 
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    Two toxin polypeptides desgnated RSAPⅢ and RSAP Ⅳ were isolated from sea anemone Ac-tinia cari.Toxins isolation was accomplished by freezing-thawing extraction, fractional acetone precipita-tion, cation exchange chromatography on SP Sephadex C-25 and reverse phase HPLC on ODS C18. Theywere found to be homogenous by SDS-PAGE, and their moleculax weight at m/z 5327 and m/z 5310 re-spectively were determined by MALDI-TOF-MS.RSAP Ⅲ possessed a bioactivity on sodinm channel inGuinea pig cardiac cell to inhibit inward Na+ currents, which is contrary to that of all sea anemone toxinsisolated so far.
    A Review of Delta-Sleep-Inducing Peptide
    ZHOU Chuang, TIAN Gui-Ling, YE Yun-Hua
    2002, 23(4):  610-616. 
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    Delta sleep-inducing peptide (DSIP) was the first sleep-factor whose chemical structure hasbeen identified.Synthesis of DSIPby means of various methods, such as solution method, solid phasemethod, enzymatic promotion method and genetic engineering method, was discussed.Some new biologi-cal activities other than the somnogenic effect of DSIPwere introduced.The structure-activity relationship(SAR) of DSIPand con formational study of this peptide in solution were also presented.Some approachesof further studies on DSIPwere suggested.
    Molecular Design of Calixarenes(VI)- Synthesis and Crystal Structure of a Novel Sulfonamino Calix[4]arene Derivative
    ZHAO Bang-Tun, ZHANG Ning, LIU Yu, CHEN Qi-Fa
    2002, 23(4):  617-619. 
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    A novel calix[4]arene derivative (2), 5,11,17, 23-tetra-tert-butyl--25, 26-dihydroxy-27, 28-[bis(p-toluenesulfonylaminoethoxy)]calix [4]arene was synthesized in a 90% yield by the reaction of 5,11, 17, 23-tetra-tert-butyl-25, 26-dihydroxy-27, 28- [bis (β-aminoethoxy)]-calix [4] arene (1) and p-tolue-nesulfonyl chloride in dry CH2C12 in the presence of NEt3.compound 2 crystallizes in triclinic space group P1, with a = 1.20444(11) nm, b = 1.61735(14) nm, c = 1.77316(15) nm, a=80.050(2)°, β=76.644(2) °,γ = 82.084(2) °, V = 3.2929(5) nm3, Dc=1.135 g/cm3, Z=2, R = 0.0683.Theresult shows the flatted cone conformation with the distorted sulfonamido substituents attached to the low-er rim of compound 2 resulted from the dipole-dipole repulsive interaction.The structure of 2-acetonitrilecomplex shows that the acetonitrile lies on the pseudo crystallgraphic fourfold axis with the nitrogen atomdirecting exo and the methyl pointing inside the intramolecular cavity, which is attributed to the specificCH-π interaction between the acetonitrile CH3 group and the aromatic nuclei of host 2.
    The Preparation and Characterization of High SpecificSurface Area VPO Catalysts
    WANG Xiao-Shu, NIE Wei-Yan, JI Wei-Jie, YAN Qi-Jie, CHEN Yi
    2002, 23(4):  620-623. 
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    The high specific surface area VPOcata1yst systems were first developed by using polyethyleneglycol(PEG) as the dispersant in the organic media.Two PEGs with different molecular weights, namely,PEG 6000 and PEG 10000, were applied to this study, and the resulted VPOcatalyst had their specificsurface areas of 52 and 54 m2/g, respectively.For the VPOsample prepared without using PEG, it onlyhad a specific surface area of 19 m2/g.For partial oxidation of n-butane to maleic anhydride, it was foundthat the conversion of n-butane and the selectivity to maleic anhydride over the catalysts prepared in thepresence of PEGwere 84%-87% and 78%, respectively; while over the compared sample they are only 71% and 71%, respectively.The significant higher specific surface area of the PEG-synthesized samplemay in part account for the enhancement in catalytic activity.
    △6 Desaturase Catalyzing Linoleic Acid to γ-Linolenic Acid
    XIAN Mo, KANG Yi-Jian, YAN Ji-Chang, LIU Yan, LI Wen-Xing, BI Ying-Li, ZHEN Kai-Ji
    2002, 23(4):  624-627. 
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    The biosynthesis of γ-linolenic acid from linoleic acid with △6 desaturase, Morierella isabellina,is reported.Various factors affecting this process were studied.The results show that the yield of the γ-linolenic acid increases with the decrease of the reaction temperature and reachs a maximum when incubat-ed below 10℃.Adding malate to the reaction mixture caused a marked increase of γ-linolenic acid yield;an increased linolenic acid yield could also be obtained with the increase of pHvalue of the reaction mixtureand reached the maximum at pH 7-8.Oxygen was an essential substrate, and NADPH, CoA and ATP were inpartent cofactors for the reaction.The yield of γ-linolenic acid reached 0.21 mg/mLunder the opti-mal reaction conditions.
    Studies on Selectively Catalytic Reduction of NOx by Methane over Ag-ZSM-5 Catalysts
    SHI Chuan, CHENG Mo-Jie, QU Zhen-Ping, YANG Xue-Feng, BAO Xin-He
    2002, 23(4):  628-631. 
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    Ag-ZSM-5 catalysts were investigated for the selectively catalytic reduction of NO by methanein the excess of oxygen.The adsorption properties of NOx and the reaction of absorbed NOx with CH4 werestudied through TPD and TPSR measurements.NOx was effectively and selectively reduced by CH4 overAg-ZSM-5 catalysts.The co-adsorption of NO and O2 over Ag-ZSM-5 catalyst led to the formation of ad-sorbed NO3 species, which could be effectively reduced by CH4. Even in the presence of O2, NO3 specieswere more reactive than O2. The priority of CH4 reaction with surface NO3-species to form N2 was clearlyobserved.
    The Decomposition of NO in Microwave Discharge
    TANG Jun-Wang, YANG Huang-He, REN Li-Li, WANG Ai-Qin, MA Lei, ZHANG Tao, LIN Li-Wu
    2002, 23(4):  632-635. 
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    The decomposition of NO in a continuous microwave discharge was investigated.When(NO,He) mixture was used as the reactant, almost all NOcan be converted to N2.In(NO, O2 ) He) system,the conversion of NO was nearly 80%, and the selectivity of N2 was 80%.When adding 5% H2O to(NO,O2, He) system, the productivity of N2 was not changed basically.However, as the microwave power wasincreased, the conversion of NO increased, and the selectivity of N2 increased even more.The effects ofNOand O2 concentrations, and flow-rate on NO removal were also observed in the microwave discharge.
    Quantum Chemical Calculation on the Electronic Properties of OrganicMolecules as Templates in the Synthesis of AlPO4-5 Molecular Sieves
    LI Bao-Zong, GUO Yong-Min, PANG Wen-Qin
    2002, 23(4):  636-639. 
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    We report here the geometry structures and electronic properties of 23 typical organic moleculartemplates which can lead to the formation of AlPO4-5 molecular sieve.The molecular graphics techniqueswere utilized to study the geometry and dimension properties, while the semi-empirical molecular orbitalPM3 calculations were adopted to study the electronic properties of the above organic molecules.Furthermore, the interaction of various organic molecules with a suitable cluster model of the AlPO4-5 frameworkwas studied by PM3 calculations.The results showed that the descriptors from quantum-chemical calcula-tions could be successfully used as consulting criterion for the choice of organic templates in the synthesis of AlPO4-5 molecular sieves.
    A Strong π-Type Secondary Hydrogen Bond in the CH2F…H2O
    WU Di, LI Zhi-Ru, ZHENG Zhi-Ren
    2002, 23(4):  640-643. 
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    By means of ab initio calculations of MP2/6-311+G(2d, 2p) method, the optimized geometryof the CH2F2…H2O complex is obtained.The structure of a subunit in the complex is similar to that of itsmolecule(CH2F2, H2O).It was found that the geometry structure of the complex CH2F2...H2O is close toits experimental structure.∠F…H-O= 116.5°is a large deviation from a strictly linear H-bond.It is aresult that a strong π-type secondary hydrogen bond formed.Using a probing point charge to detect theorientations of the lone pairs at atom Oof the CH2F2…H2O, we establish here a π-type secondary H-bondinteraction model.Because long pair ni and CHi(i=1, 2) is almost parallel and in a plane, the additionalsecondary H-bond between ni and CHi(i=1,2) formed.The double π-type H-bond is very strong.Fur-thermore, the stabilized energy of bending H-bond comes from π-type H-bond (△Esb= -0.0658eV) isalso calculated.The stabilized energy of bending H-bond is very large, 46.6% of the interactrion energy of CH2F2…H2O complex.It is shown that the double π-type secondary hydrogen bond is very strong.
    Relationships Between Solvent Molecule Tridimensional ElectrostaticPotentials and Solubilities of Several Drugs in Individual Solvents
    ZOU Jian-Wei, SHANG Zhi-Cai, YU Qing-Sen
    2002, 23(4):  644-647. 
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    Ab initio optimizations at HF/6-31G* level and subsequent electrostatic potential calculationshave been performed for a group of 54 solvent molecules.Good correlation of solubilities of four usualdrugs, paracetamol, lidocaine, haloperidol and sulfadiazine in individual solvents with the computed quanti-ties derived from solvent molecule electrostatic potentials has been obtained.We find that Vmin, Vs,max, Ⅱ and σtot2 can be well used to predict the solubility behavior of the above drugs.
    Quantum Chemical Study of Transition Metal Chromium-PhosphorousBinary Clusters CrP4+ and CrP8+
    WANG Su-Fan, FENG Ji-Kang, SUN Chia-Chung, GAO Zhen, KONG Fan-Ao
    2002, 23(4):  648-651. 
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    The possible geometrical structures and relative stability of transition metal chromium-phospho-rous clusters CrP4+ and CrP8+ are explored by means of density functional theory (DFT) quantum chemicalcalculations (B3LYP).The most stable geometrical structure of CrP4+ and CrP8+ are obtained.The conclu-sion may be used to explain the relative laser photodissociation experiment.
    Studies on the Relationship Between Electronic Structuresand Catalytic Properties of Dawson HPA Anion
    XIAO Shen-Xiu, YANG Sheng-Yong, CHEN Tian-Lang, WANG Rong-Shun
    2002, 23(4):  652-655. 
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    The electronic structures of Dawson HPA anion(P2M18O62)6-(M=Mo,W) have been calculat-ed by the discrete variational method coupled with the first principle density functional theory (DFT-DVM).The results show that the difference of the chemical properties of polar and equator sites exists.The reduction electrons will be introduced mainly into equatorial metal atoms.The active centers of(P2Mo18O62)6- are Mo, Opb, Oet, Oei and that of (P2W18O62)6- are W, Opb, Oet The redox effect of(P2Mo18O62)6- is stronger than that of (P2W18O62)6-, but their acidities are quite the opposite, which areall the same as those of (PM12O40)3- (M=Mo, W).
    Alkane Oxidation on Co- and Mn-containing MolencularSieves by Molecular Oxygen
    TIAN Peng, XU Lei, HUANG Tao, XIE Peng, LIU Zhong-Min
    2002, 23(4):  656-660. 
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    MeAlPO-5, MeAPSO-35, MeAlPO-l8 and MeAPSO-18(Me=Co, Mn) were prepared by hy-drothermal synthesis and were characterized by XRDand TPD(NH3).Their catalytic properties for theoxidation of octane were studied by using oxygen as the oxidant.In the oxidative products, there were oc-tanones, octanols, cracked oxygenates and oxygenates with more than one functional group.The selectivi-ty over different catalysts was similar.The ratio of n(octanone)/n(octanol) on MeAPSOwas higher thanthat over the same type MeAlPOmolecular sleve.The experiment of catalyst removal showed the oxida-tion was a heterogeneous reaction.Moreover, the effects of reaction time and temperature on the oxidationwere also investigated.According to the results, we discussed the reaction mechanism.
    Investigations on Dissolution Mechanism of the NiO Cathode Materialsin MCFC by In-situ Raman Spectroscopy
    CHEN Li-Jiang, CHENG Xuan, LIN Chang-Jian, HUANG Chao-Ming
    2002, 23(4):  661-664. 
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    The investigation of dissolution and degradation mechanism of NiOcathode in Molten CarbonateFuel Cell (MCFC) has recently attracted considerable attention.In this work a novel in-situ Raman spec-troscopic technique were developed to study the CO2 microscopic action in the dissolution of NiO.The re-sults indicate that CO2 tend to adsorb on the surface of NiO, and the adsorbing CO2 is prone to being des-orbed in molten carbonate under O2 contained atmosphere, due to the strong reaction between the adsorded CO2 and active O2 on the NiOsurface.
    The Binding of Dodecyloxypropyl-β-hydroxyltrimethyl AmmoniumBromide on Different Polyanions
    CHEN Ai-Min, XU Gui-Ying, ZHENG Li-Qiang, SHEN Qiang, WEI Xi-Lian
    2002, 23(4):  665-669. 
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    The binding of cationic surfactant dodecyloxypropyl-β-hydroxyltrimethyl ammonium bromide(C12NBr) on different polyanions, such as hydrolytic polyacrylamide (HPAM), hydrophobic modifiedpolyacrylates(AMB, AMBA), were investigated by using a potentiometric technique and surface tensionmeasurements at (30.0±0.1)℃.The binding isotherms of C12NBr to HPAM show a cooperative charac-teristic nature: the binding suddenly occurs and is soon saturated within a very narrow concentration range.The sudden onset of binding is referred to as the critical aggregation concentration(cac), in analogy withcmc in micelle formation.The cac value, however, is 1.5 orders of magnitude lower than the cmc.Thebinding of C12NBr to hydrophobic modified polyelectrolytes has begun at very low cf and show noncoopera-tive.For the two polyelectrolytes AMB and AMBA, a slow and continuous increase in β with the increaseof cf is observed.This is caused by the presence of hydrophobic microdomains formed by the polyelec-trolytes concentration of surfactant.The surface tension is otherms of C12NBr/HPAMexhibit two aggrega-tion concentration cT1, cT2, and cT1<cmc<cT2.But from the surface tension of mixture of c12NBr and hy-drophobic modified polyelectrolytes, we get a 1ower cmc.It is because that C12NBr molecules interact withpolymer by electrostatic on air-solution interface, and form ordered compact structure of surfactant-poly-mer complex.
    Electronic Structure and Related Properties of di-NuclearSilver Complex with Folded Structure
    ZHENG Kang-Cheng, KUANG Dai-Bin, SHEN Yong, KANG Bei-Sheng
    2002, 23(4):  670-673. 
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    Theoretical studies on the weak π-π interaction-controlled di-nuclear Ag (I) complexAg,(MPTQ)22+ with folded structure were carried out with DFTmbthod at B3LYP/LanL 2DZlevel.Theelectronic structure of the complex, the characteristic of its bonding, the mechanism of π-π interactions,the atomic net charge populations and the related properties of the complex have been investigated.The re-sults show that there is a weak direct π-π interaction between the two silver atoms in the complex.TheHOMOof the complex is mainly populated on the π-p orbitals of the aromatic rings, the σ-p orbitals of Satoms and s orbitals of C12 atoms, whereas the LUMO is predominantly located on the π*-p orbitals of thearomatic rings.The electronic spectrum of the ground state of the complex may be predicted to assign tothe n→π* CTband from the n-p orbitals of Sand s orbitals of C12 to the π* -p orbitals of the aromaticrings.In addition, the mechanism of π-π interactions among the complex molecules was also further ex-plored.The calculation results can be better used to explain the experimental phenomena and regularities.
    Stochastic Resonance Under Modulation in a Model ofElectrooxidation of Formic Acid
    PI Zong-Xin, XIN Hou-Wen
    2002, 23(4):  674-677. 
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    Stochastic resonance(SR) is modulated in a model of electrochemical oxidation formic acid onPt.The driving current and the saturation coverage for carbon monooxide are two control parameters inthe model.When the driving current is perturbed by a period signal and noise, oscillations induced by noiseare observed near Hopf bifurcation point.The interspike distributions being the most order with the incre-ment of noise intensity indicates the occurrence of SR.The signal in the saturation coverage for carbonmonooxide may modulate the stochastic resonance.The initial phases and periods of the modulation signaldetermine the results of modulation.
    Electrocatalytic Activity of Nanocrystalline TiO2 Film Modified Ti Electrode
    CHU Dao-Bao, SHEN Guang-Xia, ZHOU Xing-Fu, LIN Chang-Jian, LIN Hua-Shui
    2002, 23(4):  678-681. 
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    The precursor Ti(OEt)4 was prepared by anodic dissolution of metallic titanium in absolutionethanol and directly hydrolyzed to prepare nanocrystalline TiO2 film on titanium electrode (Ti/nano-TiO2)by a sol-gel process.TEM and XRD were used to characterize the structure of nanocrystalline TiO2 film(Anatase, 25 nm).Redox behavior and electrocatalytic activities of the Ti/nano-TiO2 electrode were in-vestigated by cyclic voltammetry and cyclic osteryoung square wave voltammetry and bulk electrolysis.Theresults indicated that there were two pairs of well-defined redox peaks for Ti/nano-TiO2 electrode in 1mol/L H2SO4, with Epc1= -0.56 V, Epc2= -0.95 V(vs.SCE) at 100 mV/s and the heterogeneous catalyticredox behavior of this electrode in nitrobenzene(NB) in H2SO4 medium.It was found that the indirect elec-troreduction of NBto p-aminophenol(PAP) by Ti(Ⅳ)/Ti(Ⅲ) redox system occurred on nanocrystallineTiO2 film surface.In preparative electrolysis under optimal conditions, the average yield and current effi-ciency for PAPwere 91.6% and 95.2% respectively.
    Studies on the Preparation and Luminescence Oxygen Sensor of the Sol-gelFilm Containing Unsaturated Long Chain Ester Moieties
    ZHU Hui, MA Yu-Guang, FAN Yu-Guo, SHEN Jia-Cong
    2002, 23(4):  682-684. 
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    The new sol-gel-derived silica films containing unsaturated long chain ester moieties were fabri-cated by spin-coating on to glass substrates.The films were pre-doped with the oxygen-sensitive lumines-cent Ru(bpy)32+, whose emission are quenched in the presence of oxygen.Compared with traditional te-traethyl orthosilicate (TEOS) /Ru (bpy)32+ films, 3-(trimethoxysilyl)-propyl methacrylate (PMA-TMS)/Ru(bpy)32+ films were found to be better in film-formation property, higher in quenching response for oxy-gen and shorter in response time.All improvements are due to the unsaturated 1ong chain ester moieties inresultant sol-gel films.
    Nanocomposite Films of Conductive Polymer/SemiconductorNanoparticles(Ⅱ)- Photoelectrochemical Properties
    LI Dong-Sheng, LU Gong-Xuan
    2002, 23(4):  685-689. 
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    Using layer-by-layer self-assembly techniques, we successfully constructed nanostructured mul-tilayer films of conjugated polymer (sulfonic acid ring substituted polyaniline, SPAn)/semiconductornanoparticles(Q-CdS).Cyclic voltammograms of single layer film of SPAn in 0.1mol/L Na2SO4 solution(pH=3.0) consists of two redox peaks.The electrochemical processes associated with the peaks are twosteps redox doping.The S2- in the composite films is unstable and easily oxidized to product S, S2O32- and SO42- as being determined by X-ray photoelectron spectroscopy.The films of the first layer SPAn exhibiteda weak photoinduced cathodic current over the potential range between Oand -600 mV(vs.SCE) in 0.1mol/L LiClO4 solution in acetonitrile.The self-assembly films of SPAn/Q-CdSexhibited a photocathodicacurrent under cathodic bias and photoanodic current under anodic bias.In contract, the films of poy(sodi-um 4-styrenesolfonate)/Q-CdSonly exhibited a photoinduced anodic current from - 500 to 600 mV.Itimplied that the state(doping or undoping) of the conjugated polymer play an important role in determiningthe photoelectrochemical properties of the films.
    Studies on the Metastable Phase Equilibrium of Na+, K+,Mg+ //Cl-, SO42--H2O Quinary System at 15℃
    JIN Zuo-Mei, ZHOU Hui-Nan, WANG Li-Sheng
    2002, 23(4):  690-694. 
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    This paper presents the experimental date of metastable phase equilibrium of Na+, K+,Mg+ //Cl-, SO42--H2O quinary system at 15 ℃, from which the metastable phase diagram is drawn.lt con-sists of nine rigions of crystallization saturated with sodium chloride: potassium chloride, thenardite(Na2SO4), glasserite(3K2SO4·Na2SO4), schoenit(K2SO4·MgSO4·6H2O), astrankit(MgSO4·Na2SO4·4H2O), carnallite (KCl· MgCl2· 6H2O), epsomite (MgSO4·7H2O), hexahydrite (MgSO4·6H2O)and bischofit(MgCl2·6H2O).Alarge difference is found between the obtained metastable phase diagramat 15℃ and Van't Hoff's stable phase diagram at 25℃.The crystallization of leonite(K2SO4·MgSO4·4H2O), kainite(KCl·MgSO4·3H2O), magnesium sulfate quinhydrate(MgSO4·5H2O) and starkeyite(MgSO4·4H2O) disapear and the crystallization regions of schoenit greatly increased.Comparing themetastable phase diagram of Na+, K+, Mg2+ //Cl-, SO42- at 15 ℃ with the metastable phase dia-gram at 25℃ and 35℃ by the authors, it is found the crystallization region of schonite (includingleonite) at 25℃ is the largest, and at 35℃ is the smallest with the temperature rising from 15℃ to 35℃, the crystallization regions of glasserite parallelly moved toward KCl region, which made the KCl regiondecreasing and the Na2SO4 region increasing; with the temperature rising from 15℃, 25℃ to 35℃, thesodium containing and water containing decrease consequently.
    Synthesis, Structure and Thermal Property of Tri(1-oxo-2, 6, 7-trioxa-1-phosphabicyclo[2.2.2]octane-methyl)phosphate
    LI Xin, OU Yu-Xiang, ZHANG Yun-Hong
    2002, 23(4):  695-699. 
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    A novel caged bicyclic phosphate flame retardant tri(1-oxo-2, 6, 7-trioxa-1-phosphabicyclo[2.2.2]octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2, 6, 7-trioxal-phos-phabicyclo[2.2.2]octane(PEPA) and phosphorus oxychloride in this paper.Its structure was character-ized by elemental analysis, FTIR, 1H NMR, 31P NMR and X-ray diffraction analysis.The crystals aremonoclinic, space group Cc, with unit cell dimensions a= 1.2754(3) nm, b=1.8582(4) nm, c=1.1269(2)nm, V= 2.3242(8) nm3, four molecules per unit cell.The final R=0.0322, Rw=0.0907 for 2177 unique reflections.The crystal data reveal that the three cages in Trimer are structurally equivalent,and that the corresponding average bond lengths and bond angles are appropriate.The results of TG-DTA and DSC have convincingly demonstrated that Trimer has an excellent thermal stability and char formingcharacteristics, which is expected to be a promising intumescent flame retardant.
    Molecular Recognition of Zinc Porphyrin Dimers to DABCO andCorresponding Thermodynamic Study
    REN Qi-Zhi, ZHU Zhi-Ang, JIANG Dong-Qing, HUANG Jin-Wang, JI Liang-Nian, CHEN Yong-Ti
    2002, 23(4):  700-705. 
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    A series of p/p type zinc porphyrin dimers covalently linked with a flexible chain are synthe-sized and characterized.The molecular recognition of zinc porphyrin dimers and corresponding monomer torigid nitrogenous bidentate ligand DABCO (1,4-diazobicyclo[2,2,2]octane) are described in detail by 1H NMR and UV-Vis spectroscopy.DABCOcan bind inside the cavities of porphyrin dimers and form aternary sandwich complex as the length of the alkoxyl chain is long enough and their molar ratio is suit-able.The thermodynamic parameters such as the equilibrium constants, stoichiometric numbers, and thecorresponding enthalpies and entropies of the binding behavior are also obtained by UV-Vis spectroscopy.
    Preparation of Methanol Synthesis Catalyst Cu/ZnO/Al2O3by Gel-network Coprecipitation Method
    HONG Zhong-Shan, DENG Jing-Fa, FAN Kang-Nian, CAO Yong
    2002, 23(4):  706-708. 
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    A novel gel-network-coprecipitation process has been proposed to prepare ultrafine Cu/ZnO/Al2O3 catalysts for methanol synthesis from CO2 hydrogenation.Compared to the catalysts prepared via theconventional coprecipitation method, the new catalysts prepared via gel-network-coprecipitation methodexhibit much higher BETsurface area and metallic copper specific surface area, much smaller crystallitesize and higher catalytic activity and selectivity in CO2 hydrogenation to methanol.The effect of the gelconcentration of gelatin on the structure, morphology and the catalytic properties of the Cu/ZnO/Al2O3catalysts for methanol synthesis from hydrogenation of carbon dioxide were also investigated.
    New Formulas of Matrix Element of MajoranaOperators of Four-atomic Molecules
    WANG Mei-Shan, DING Shi-Liang, LI Bo-Fu, ZHANG Gang
    2002, 23(4):  709-711. 
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    We first studied the relationship between coupling tensor operators of the product of three ten-sor operators of SO(4) and Majorana operators of four-atomic molecules.We have gained the general for-mulae of the matrix elements of the coupling tensor operators of product of three tensor operators by usingGeneralized Wigner-Eckart theorem.As an example, we calculated the matrix elements of Majorana oper-ators and gave the new simpler formulae of them.
    EXAFS Characterization of Sulfur-tolerant Pd-Pt/USY Catalystfor Deep Hydrodearomatization of Diesel
    YANG Jun, ZHANG Xi-Wen, HAN Chong-Ren, LU Guan-Zhong
    2002, 23(4):  712-714. 
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    The metal dispersion and sulfur tolerancc of Pd-Pt/USYcatalysts with different n(Pd)/n(Pt) ratios was investigated by using an extended X-ray absorption fine structure(EXAFS) method.The resultsindicate that the presence of Pd in Pd-Pt/USY catalyst can restrain Pt particles from agglomerating, so thePt dispersion of catalyst calcined in air increases as the increasing of n(Pd)/n(Pt) ratio.There are morePd/Pt alloy metal particles in sulfided Pd-Pt/USY catalyst with n(Pd)/n(Pt) = 4/1, which has a benefitto the improvement of sulfur-tolerant performance ot the catalyst.The sulfur-tolerant performance of Pd-Pt/USYcatalyst is improved obviously in the presence of Pt.On the other hand, the higher dispersion ofPt on oxidic catalyst is a main reason for thc forming of more Pd-Pt alloy metal particles on the sulfidedcatalyst.
    Chemisorption of H2 and Coadsorption of H2 and CO on Rh2Co2/Al2O3
    CHEN Yao-Qiang, GONG Mao-Chu, ZHU Xiao-Hong, MING Hong, TANG Shui-Hua
    2002, 23(4):  715-717. 
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    The adsorption of H2 as well as coadsorption of H2 and COon Rh2Co2/Al2O3 catalyst has beenstudied using in situ FTIR dynamic method.The band at 1959 cm-1 for Rh-H vibration on Rh2Co2/Al2O3 (w=3%) was observed and increased in intensity without shift to low wavenumber as H2 coverageincrease.In the dynamic process of CO adsorption on Rh2Co/Al2O3 preadsorbing H2-TP(in H2 and CO),the bands for the gem-dicarbonyl species, the linear COspecies and the bridge carbonyl species were lostand the bands for carbonyl hydrides were observed at 293 K.At about 473 K, the C-O bond of rhodiumcarbonyl hydrides starts to break down and CO hydrogenation reaction occurs.It can be concluded that thescission of C-O bond under the conditions of CO hydrogenation is via rhodium carbonyl hydrides.
    Changing Rules of the Intrapair and Interpair ElectronCorrelation Energy on NHn (n=1-3)
    ZHUO Shu-Ping, WEI Ji-Chong, JU Guan-Zhi
    2002, 23(4):  718-720. 
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    The intrapair and interpair electron correlation energies of NH, NH2, NH3 molecules are calculated at MP2/6-311 ++G(d) level by using MP2-OPT1 method of MELD PROGRAM.The results indi-cate that the intrapair electron correlation energy of 1s2 electrons of Natom is transferable in these NH-con-taining molecules.From Nto NH3 systems, the total correlation energy changes by a value in a range withthe increase of each N-H bond.This shows that the electron pair energy of N-H bonding pair has some-what transferability in these systems.The comparison of NH-containing systems with their isoelectronicatoms shows that the contribution of higher-excitation terms to the total correlation energy are larger thanthose of the corresponding isoelectronic atom systems.
    Preparation of Highly Ordered Polyaniline Nano-fibrils Arrayby Template Synthesis
    WANG Zhen, LI Hu-Lin
    2002, 23(4):  721-723. 
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    The highly ordered polyaniline(PANI) nano-fibrils array was prepared by template synthesiswithin the anodic aluminum oxide (AAO) template.The surface appearances of PANIfibril arrays wereobserved by using scanning electron microscopy(SEM) and X-ray energy diffraction spectroscopy(EDS).X-ray photoelectron spectroscopy(XPS) provides an enough surface analysis evidences for the PANI/AAOcomposite membranes.The length and the diameter of PANIfibrils are dependent on the thickness andpore diameter of porous anodic aluminum oxide(AAO) template.
    Artificial ESR Study on Participation of Histidine in the SecondaryElectron Transfer Inside Photosystem Ⅱ Reaction Center
    LIU Hai-Feng, LIU Yang, WANG Peng, ZHANG Qi-Yuan
    2002, 23(4):  724-726. 
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    Upon the addition of imidazole (Im) to the artificial photosynthetic systems composed byZnTPP/BQand p-H2TPP-NH-CO-CH2-BQ, half-lives of ESR signals of semibenzoquinone radical BQ·- and -CH2-BQ·- are significantly prolonged by the secondary electron transfer pathway from imidazole toporphyrin cation in polar solvents.The imidazole cation radicals(Im·+) can simultaneously be identified byPBN(spin trap) both in BQ/ZnTPP/Im and p-H2TPP-NH-CO-CH2-BQ systems when laser-flashing.Onthe basis of our ESRobservation, a secondary electron transfer mechanism can be proposed as follows;(1) TPP+hv→TPP*; (2) TPP*+BQ→TPP·++BQ·-;(3) TPP·+ +Im →TPP+Im·+.
    π-π Interactions of Donor and Acceptor SubstitutedBenzylidene Derivatives
    YANG Wen-Sheng, JIANG Yue-Shun, ZHUANG Jia-Qi, LI Tie-Jin, TIAN Mei
    2002, 23(4):  727-729. 
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    Six benzylidene derivatives with dialkylaniline substituents as the electron donor and pyridine orpyridinium substituents as the acceptor were synthesized and their intermolecular π-π interactions werestudied.It is found that the derivatives with dialkylaniline substituent as donor and pyfidine group as ac-ceptor tended to form J-aggregates in solution and solid state and their electronic configurations of excitedstates were subjected to great changes, while the derivatives with diakylaniline substituent as donor andpyridinium group as acceptor tended to form H-aggregates and the configurations were subjected to smallchanges.The strength of the π-π interactions can be mediated by the length of the alkyl substituents.
    Characteristics of Bioelectrochemical Response ofan Amine Oxidase-modified Polyaniline Electrode
    XUE Huai-Guo, SHEN Zhi-Quan, LI Yong-Fang
    2002, 23(4):  730-733. 
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    An amine oxidase-modified polyaniline electrode(PANI/AO) was formed by immobilization ofamine oxidase in polyaniline film by electrochemical doping method.The electrode has a fast response forhistamine and the reaction is controlled by the enzyme kinctics.The apparent Michaelis constant, optimunpHand activation energy for the immobilized amine oxidase are 0.21 mmol/L, 7.3-7.6 and 76kJ/mol,respectively.The enzyme electrode exhibited a good stability, which can be used for the determination ofhistamine.In addition, the electrochemical characteristics of the enzyme electrode were studied by cyclicvoltammetry and impedance measurement.
    Microstructure and Morphology of PolypropyIene/Clay NanocompositesSynthesized via Intercalative Polymerization
    MA Ji-Sheng, ZHANG Shi-Min, QI Zong-Neng, HU You-Liang, ZHANG Shu-Fan
    2002, 23(4):  734-738. 
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    Polypropylene/montmorillonite(PP-MMT) nanocomposites were synthesized via intercalativepolymerization.The morphology evolution and microstructure of the nanocomposites were investigated bymeans of polarized optical microscopy(POM), scanning electron microscopy(SEM), transmssion electronmicroscopy(TEM) and wide angle Xray diffraction (WAXD).It has been found that the big primary MMT particles were mostly dissociated into smaller secondary particles, which consists of 2~20 individual MMT layers and expanded gallery distance full of PPchains.The morphology evolution model of the PP-MMT during the intercalation polymerization is discussed.It has been also found that the presence of MMT influences the spherulite morphology of the polypropylene in the PP-MMT nanocomposites with in-creasing of MMT content in nanocomposite, the dimension of the spherulite reduced and the shape becamedistorted.
    Toughness, Morphology and Rheology of Toughening System ofPoly(phenylene oxide) with Maleated HydrogenatedStyrene-butadiene Block Elastomer
    WANG Xiao-Dong, ZHANG Qiang, JIN Ri-Guang
    2002, 23(4):  739-743. 
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    The toughening system of poly(phenylene oxide) (PPO) blends with hydrogenated styrene-bu-tadiene block elastomer(SEBS) and a version grafted with maleic anhydride(SEBS-g-MA) was investigat-ed.Dfferential scanning calorimeter thermograms demonstrated that PPO was miscible with SEBS, whichshowed a unique Tg, but PPO was partially compatible with SEBS-g-MA because there were two of Tg.Toughness research revealed that PPO/SEBS blends achieved litter higher notched Ized impact strengththan pure PPO.However, SEBS-g-MAcould toughen PPO effectively and the blends reached supertoughness with a notched Izod impact strength of 1260J/m at the SEBS-g-MA content of 20%.Trans-mission electron microscopy showed a typical "sea-island" structure in PPOdomain.However, SEBS-g-MA demonstrated a network structure in PPOmatrix.Toughness improvement for PPOblends withSEBS-g-MAwas contributed to stress releasing in micro-cavity.The rheological properties study revealedthat the apparent viscosity of PPO/SEBS blends was improved with the increasing of SEBScontent, butopposite for PPO/SEBS-g-MA blends.
    Studies on the Energy Compensation Effect in the Hybrid Polymerization ofHexamethoxymethyl Melamine(HMMM)-polyol-acrylate
    HONG Xiao-Yin, CHEN Qi-Dao, CHEN Lin, CHEN Ming, WU Rui-Guang, MAO Huai-Qing
    2002, 23(4):  744-747. 
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    The hybrid polymerization of hexamethoxymethyl melamine (HMMM)-polyol-acrylate and acidinvolves the condensation reactions of HMMM-polyol and the free radical polymerization of acrylate.DSC investigation shows that catalyzed by HMMM-polyol and acid, the free radical poymerization of acrylatetakes place at a lower temperature and the released energy can be transferred to the endothermic condensa-tion reactions of HMMM efficiently, saving much energy needed for the curing.To lengthen the shelf timeof the formulation, we have also investigated the hybrid poymerization system in which the latent acid cat-alyst was used as the source of acid, and observed the energy compensation effect, too.
    Synthesis of Y-type Macromonomer Based on 2-(N,N-Dimethylamino)ethylMethacrylate via Oxyanoin-initiated Polymerization
    NI Pei-Hong, PAN Qi-Sheng, FU Shou-Kuan
    2002, 23(4):  748-750. 
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    A novel well-defined water-soluble macromonomer based on 2-(dimethylamino) ethyl methacry-late(DMAEMA) was synthesized by using functional initiators such as potassium alcoholate of trimethylol-propane allyl ether via oxyanion-initiated polymerization.GPC and 1H NMR studies confirmed that themacromonomers had narrow molecular weight distribution and each Poly(DMAEMA) chain contained apolymerizable allyl group.The macromonomers were highly surface active in aqueous media.They havepotential applications in preparation of surface-clean and functional latexes both as effective stabilizers andas co-monomers.