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    24 January 1993, Volume 14 Issue 1
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    Articles
    Studies on Novel Mixed Ligand Complexes of Rare Earth Acetylacetonates and Dibenzo-18-Crown-6 by Using Reflectance Spectrophotometry
    WANG Xiao-Ling, YAO Ke-Min
    1993, 14(1):  1-4. 
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    Aseries of novel mixed ligand complexes of rare earth acetylacetonates and dibenzo-18-crown-6 (Ln(acac)3 ·DB18C6, where Ln = La-Lu and Yexcept Ce, Pm, Sc) obtained in the author' s laboratory were characterized by UV-reflectance spectrophotometry and more informations were obtained from the reflectance spectra by using integral sphere.in the UV-region, the absorption peaks appearing in n→π*
    Synthesis and Characterization of Rare Earth Complexes of 3-Ferroeenylacrylate
    LIU Zhan-Mei, LIAN Xi-Shan, DING Er-Run
    1993, 14(1):  5-8. 
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    In this paper, thirteen novel rare earth complexes of 3-ferroeenyiacryiate with a general formula REL3·H2O(RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb; L = C5H5FeC5H4CH = COO-) were synthesized by the reaction of trivalent rare earth chloride with sodium 3-ferrocenylacrylate in anhydrous alcohol.The cpmplexes were characterized by means of elementary analysis, molar conductance, SRand TG-DTA.The much lower conductance values support the view that they are much less ionized.In IRspectra, the C=Cand C-Hbands of the ferrocenyl(Fc) are not greatly changed after the coordination, which shows that RE3+ ion with Fc has not directly action.The various bands associated with the carboxylate group motion are considerably altered.In the complexes, vas(COO-) shifts to lower frequencies(32-35 cm-1), v,(COO-) shifts to higher frequencies (3-7 cm-1).The absorption band in the region495-498 cm-1 is attributed to O - Mmotion.These results indicate that the carboxylate group coordinate to the rare earths as a symmetrical biden-tate iigand.In addition, the certain relationship between vas(COO-) and the atomic numbers of rare earths is presented.TG-DTAindicated that the complexes lose water at about 90℃ and begin to decompose endothemically at about 216℃.The results of X-ray powder diffraction show that all complexes are crystalline materials.
    Synthesis and Studies on Thermal Stability of Dicyclopentadienyl Lanthanide 8-hydroxyquinolinolato Complexes
    WU Zhong-Zhi, XU Zheng, YOU Xiao-Zeng
    1993, 14(1):  9-12. 
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    By using the reaction of Cp3Ln(Cp = C5H5; Ln = Sm, Dy, Ho) with 8-hydroxyquinoline (HL)(1:1 molar ratio) in tetrahydrofuran at room temperature, three new organoianthanide complexes with the general formula Cp2LnL( Ln = Sm, Dy, Ho) were synthesized.All the complexes were characterized by elementary analysis, IR, XPS, MSspectra and cryoscopic method for molecular weight determination.The results of elemental analyses confirmed to the formula Cp2LnL.The IRspectra show the characteristic absorptions of η5-Cp group at about 3100, 1440, 1010, 780 and 250 cm-1, and 8-hydroxyquinolinoiato metal chelates near 560 cm-1.XPSdata revealed that the N,, binding energy of Lligand in each complex is higher than that of sodium salt of 8-hydroxyquinoline, which indicates that Liigand coordinates to metal through nitrogen and oxygen atoms to form an intramolecular five-membered chelating ring.Molecular weight determination by cryoscopic method in benzene suggests each complex exists as a dimer with oxygen atoms of Lligands as bridging atoms.MSspectra show only the monorneric molecular ion peaks of the complexes, which may indicate that upon heating, the dimeric complexes easily dissociate into a monomer.Due to the effect of chelating coordination, the title complexes have higher stability compared to the corresponding Cp2LnCl and Cp3Ln complexes.The thermal stabilities of the complexes were studied and compared eath other.Complex Cp2SmLis thermally unstable and tends to decompose into Cp3Sm and SmL3 at above 180℃.
    Synthesis and Properties of Tetra(5,6-dichloro-1, 4-dithiacyclohexeno)-tetraazaporphyrin and Its Manganese (Ⅱ), Iron(Ⅱ), Nickel (Ⅱ), and Copper (Ⅱ) Complexes
    TANG Yue-Qun, PENG Zheng-He, QIN Zi-Bin
    1993, 14(1):  13-15. 
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    Tetra(5,6-dichloro-1,4-dithiacyclohexeno)tetraazaporphyrin H2TCTAPand its transition metal complexes MTCTAP( M = Mn(Ⅱ), Fe(Ⅱ), Ni(Ⅱ), Cu(Ⅱ)) have been synthesized by chlorization of chlorine-free tetraazaporphyrines, and characterized by elemental analysis, IR, and TG-DTA.H2TCTAPand MTCTAPare thermostable at 427 and 450℃, respectivily.Its electron spectra in DMFhave been observed at -630 nm(Qband), 350 nm(Bband), and at -460 nm(flu-orescence).Electron paramagnetic resonace spectra of the CuTCTAPpowder at 77Khave given anisotropic tensors g// = 2.308,g⊥ = 2..067, A// = - 0.133 cm-1, A⊥ = 0.079 cm-1.
    Synthesis and Activity of Heteropolysilicotungstate Containing Transition Metal Elements
    WU Zhi-Yun, WANG Jun, ZHAO Zhong-Qing
    1993, 14(1):  16-18. 
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    The heteropolysilicotungstates containing transition metal elements Mn2+, Co2+ and Ni2+ were synthesized.IRspectra and TPDof the samples adsorbing pyrMine were determined.The IRspectra of the heteropoly compounds are different from those of 12-silicotungtic acid and its potassium salt; the adsorption peak at 1438 cm-1 is visible, even if the sample was treated for 1 h at 200℃ under 0.5 Pa vacuum.The result implies that Lewis acid site exists in the compound.The acid site corresponds to the medium temperature peak on TPDpattern of the compoud adsorbing pyridine.
    Synthesis and Characterization of Porphyrin Within the Supercages of Faujasite
    WANG Xing-Qiao, LIANG Yue-Xia, Liu Yu-Wen, YU Lian-Xiang, LI Ying, LI Fei-Hu, CAO Xi-Zhang
    1993, 14(1):  19-20. 
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    Faujasite with porphyrin of cobalt in its supereage was prepared by the reaction of ion-exchanged zeolite with dipyrroie and characterized by the methods of UV-Vis, IR, SEMand absorption.
    Theory of Potentiometric Stripping Analysis at Ultramicrodisk-electrode
    ZHANG Zu-Xun
    1993, 14(1):  21-24. 
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    The theory of potentiometric stripping analysis at ultramicrodisk-electrode is described, which states the equations of transition time(τ), potential-time curve and the equation of differential potentiometric stripping analysis.The behavior of dt/dE-Ecurve is discussed also.
    Studies on the Determination of Zinc by Metastable Energy Transfer Emission Spectrometry
    YU Ai-Min, Zhang Han-Qi, FAN Fu-Liang, JIN Qin-Han
    1993, 14(1):  25-28. 
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    The present paper describes an metastable energy transfer emission spectrometry(MTES) for the determination of zinc.When N2 was used as support gas, the active nitrogen afterglow was produced in a microwave discharge.The sample solution was introduced with an electrothermal microsam-pie introduction system, the experimental parameters affecting the determination of zinc were examined, zinc was determined at 472.2 nm and the detection limit was 2.3 ng.The method has been employed to analyse the practical samples and the result is satisfactory.
    Studies on the Shielding Effect for LB Film of Amphiphilic Graft Star Polymer by Electrochemical Method
    GAO Qian, GUO Li-Ping, SUN Chang-Qing, ZHANG Xi, HE Ling-Feng, XU Hong-Ding
    1993, 14(1):  29-32. 
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    The shielding effect of amphiphilic graft star polymer on Y-type glassy carbon electrode was studied by cyclic voltammetry.The experimental results showed the relationship between shielding effect and degree of branching, and the condition of film formation.The factors are discussed for estimating the film defect.
    The Theory of Steady-state Voltammetric Curve at a Ultramicroring Electrode and Its Experimental Verification
    WU Zhi-Bin, ZHANG Zu-Xun
    1993, 14(1):  33-36. 
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    The present paper deals with the theory of steady-state voltammetric cure at a ultramicror-ing electrode.In order to examine the validity of the theory, experimental studies on the system of Fe(CN)64- ions in 0.5 mol/L KCl solution were carried out at a ultramicro-gold-ring electrode(τ1 = 25.7 μm, τ2 = 20.2μm).The experimental voltammograms are in good agreement with the theoretical ones.
    Investigation on Simple Oscillographic Voltammetric Curve
    ZHENG Jian-Bin, ZHU Jun-Jie, GAO Hong
    1993, 14(1):  37-39. 
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    In this paper, we present a new oscillographic titrimetric method called simple oscillographic voltammetric method.This method can overcome some faults on i 1-Ecurve in double electrolyzer.By using a single electrolyzer and a simple circuit, oscillographic voltammetric curve can also be obtained.It will be widely applied to pharmaceutical analysis.
    The Studies on Gas-Sensing Probes with a Graphite Contacted Solvent Polymeric Membrane pH Inner Electrode
    YUAN Ruo, WU Hai-Long, ZHAO Xin-Yu, HE Xiao-Mei, SHEN Guo-Li, ZHANG Yong-Hua, YU Ru-Qin
    1993, 14(1):  40-43. 
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    The present paper describes carbon-dioxide and ammonia gas-sensing probes containing neutral carriers based inner pHelectrodes.Octadecyl nicotinate (ODN), Hexadecyl nicotinate (HDN), dioctyloctadecylamine (DOODA), and dimethyloctadecylamine (DMODA), were used as neutral carries for preparation of electrodes with graphite inner contacts forming flat solvent polymeric membrane (SPM) pHsensitive tips.The results obtained show that the potentiometric response characteristics of the gas-sensing probes depend on the nature of the carriers.Carbon dioxide gas-sensing probe with ODNand ammonia gas-sensing probe with DOODAas neutral carries of the inner pHelectrodes have fair potentiometric response characteristics.Acorn navel tissue based pyruvate decarboxylase was prepared using the carbon-dioxide probe as primary electrode.The response characteristics such as electrode slope of the enzyme probe prepared was better than those of the glass inner electrode counterparts.
    Studies on Determination of Copper, Zinc, Cadmium by Electrothermal Vaporization Feeding and Low Powered MPT-AES
    YU Ai-Min, ZHANG Han-Qi, LIU Xiao-Jing, JIN Qin-Han
    1993, 14(1):  44-46. 
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    Low powered microwave plasma torch (MPT) was used as light source.When Ar was used as support gas, the sample solution was introduced with an electrothermal microsample introduction system.The experimental parameters affecting, the determination of copper, zinc and cadmium were examined, the detection limits for copper, zinc and cadmium were 3.3,1.4,1.7 ng/mL, respectively.The method has been employed to analyse the copper of practical samples and the result is satisfactory.The influence of alkaline elements on the copper, zinc and cadmium emission signal is also discussed.
    Investigation on Pulse Polarography (Ⅵ)——Numerical Solution of Equation of the Differential Pulse Polarography for Irreversible Wave Influenced by Adsorption
    ZHANG Jian-Rong, ZHANG Zu-Xun
    1993, 14(1):  47-49. 
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    The equation of irreversible wave with adsorption of both the reactant and product in differential pulse polarogeaphy is solved by Huber's method.The formulae and block diagram of numerical solution of Huber's method are shown in detail, and the influence of electrode kinetic parameters, adsorption constants, drop time, pulse height and exampled-current time on peak current of Dpp is mainly discussed in this paper.Experiments show the theoretical relationship of peak current of Dpp with Igk.is good agreement with observed result.
    Studies on the Reaction Mechanism of 2,4,6-Trinitro-2,4,6- triazacyclohexanone with 15N NMR Spectra
    ZHANG Yue-Jun, WEN Jing-Quan
    1993, 14(1):  50-53. 
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    2,4,6-Trinitro-2,4,6-triazacyclohexanone could be synthesized via the condensation of the nitrolytic fragments of DPTand urea (or nitrourea) in the nitrolytic medium.In this paper the nitrogen atoms in different positions of DPTwere labelled with 15Natoms respectively.With the help of 15N NMRspectra, the isotope distribution and abundance of 15Nlabelled atoms in the product and re-actant molecules could be determined.The results indicate that the nitrolytic fragments condensed with urea (or nitrourea) are N,N-dihydroxymethylamines without the nitro-substituent, and there exists a exchanging process between the nitro-groups in the nitrourea and in the nitrolysis agent.
    Studies on the Application of Lanthanoid Metals to Organic Reactions (Ⅳ)——The Reaction of Sm(0) on Graphite with PhCOCl
    LIU Yun-Shan, JIANG Tao, BEI Mei-Zhi
    1993, 14(1):  54-55. 
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    The zero-valent Sm on graphite has been prepared by the reduction of anhydrous SnCl3 with potassium graphite (C8K) in refluxing THFunder a purified nitrogen atmosphere.It showed a greater activity than commercial block Sm metal, and reacted with PhCOCl smoothly at r.t.to give the benzil 1, benzoin 2 and stibenediol dibenzoate 3.Compound 3 is the major product and the cis-form of 3 is the dominant among its geometrical isomers.
    Studies on the Composition of Derivatives of Lignan from Pedicularis Striata
    LIU Zi-Min, JIA Zhong-Jian
    1993, 14(1):  56-57. 
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    Further studies were led to the isolation of two new minor compounds, named as striatoside Aand B, from the ethanol extract of the whole plant of Pedicularis striata.Their structures were elucidated as the derivatives of lignan on the basis of IR, UV, 1H NMR, 13C NMR, FAB MS, EIMSand chemical methods.
    Alkylation of Isobutyric Acid and Its Derivatives
    ZHONG Ping, YIN Cheng-Lie
    1993, 14(1):  58-61. 
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    The alkylation of isobutyric acid, alkyl isobutyrate and isobutyric anhydride with 1-bromo-3-chloropropane, 1,3-dibromopropane and some monohalogen compounds was studied.The yields of these reactions and the IR, 1H NMRdata were given.
    Electrochemical Reduction Properties of Azo Dyes in Acidic Media
    PENG Xiao-Jun, WANG Ji-Tao, YANG Jin-Zong
    1993, 14(1):  62-64. 
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    The electrochemical reduction of four azo dyes in acid media were studied.All of the electro-reductions of azo groups are irreversible one-step and four-electron reductions.The ortho and para electron-withdrawing substituents(e.g.-COOBu-R) made the azo groups be reduced more easily than meta one.The azo group is prior to nitro group to be reduced in the media when a dye contains both of them.
    Synthesis of 2-Aroylamido-5-benzyl-1,3,4-thiadiazoles and Studies on Their Reactions with Benzaldehyde
    FENG Xiao-Ming, CHEN Rong, HUANG Jin-Song, ZHANG Zi-Yi
    1993, 14(1):  65-67. 
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    In this paper, thirteen new 2-aroylamido-5-benzyl-1, 3, 4-thiadiazoles 2a-m were synthesized by cyclization 1-phenylacetyl-4-aroylthiosemicarbazides la-m in ice acetic acid.Thirteen new 2-aroylamido-5-(1'-phenyl-2'-hydroxyphenylethyl)-l,3,4-thiadiazoles 3a-m were obtained by nucle-ophilic addition of benzyl carbanion of 2a-m with benzaldehyde in EtONa-EtOHsolution.The structures of compounds 2a-m and those of 3a-m were confirmed by elementary analysis, IR, 1H NMR, and MS.
    The Reactivity of Hexaethyl Phosphorous Triamide——Reaction of Hexaethyl Phosphorous Triamide, Benzaldehyde and Haloform
    ZHAO Wen-Chao, YANG Zeng-Jia, ZHAO Yu-Fen
    1993, 14(1):  68-70. 
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    At 140℃, the mixture of hexaethyl phosphorous triamide and benzaldehyde could react with chloroform, chloroform-d (CDCl3) and bromoform respectively.By means of 1RNMR, elementary analysis and isotope analysis, their products were determined as diethylamine hydrohalide respectively.Apossible mechanism is proposed.
    The Influence of Medium on the Stability of Coordination Compounds (Ⅴ)——The System of Fe(tiron)-NaClO4-C2H5OH-H2O System
    LIU Kui-Dao, CHEN Wei-Dong, LIU Qi-Tao
    1993, 14(1):  71-74. 
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    The stability of complex anion Fe(tiron)- composing of high valence cation Fe3+ and anion tiron4- in mixed solvents of ethanol-water with weight percentage of ethanol 0, 5, 15, 25, 35 and 50 was measured spectrophotometrically at 295 Kby using NaClO4 as the supporting electrolyte with ionic strength ranging from 0.1-3.9 mol/L.The thermodynamic stability constants of Fe(tiron) in various mixed solvents have been obtained by a polynomial approximation equation based on Pitzer's theory.As a comparison, the traditional Debye-Huckel equation was used to treat the same data.The results show that this polynomial approximate method is obviously superior to the previous one.It was discovered that there is a linear relation between the thermodynamic stability constants of Fe(tiron)-and the mole fraction of organic component in Mixed solvents or the reciprocal of dielectric constants of the solvents.The medium effect and the standard free energy of transfer AGtr0 for the coordination reaction:Fe3+ 4-tiron4- =Fe(tiron)- is also discussed.
    A Fitting Method of Polynomial Expansion for Unfolding Energy Level Fluctuations
    TAO Chang-Yuan, LUO Jiu-Li, YAN Guo-Sen
    1993, 14(1):  75-79. 
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    The essence of energy level fluctuations lies in the deviation of quantum distribution law from its classical counterpart which is usually considered as a smooth average of energy level data.It is the key-work to find an optimam fitting curve of original level data for the unfold of energy level fluctuatione thereby.This article is devoted to discribe the fundamental ideas concerning with energy level fluctuations and their unfolding, meanwhile to put forward a fitting method of polynomial expansion which is more universal for unfolding energy level fluctuations by means of a synthesis of different unfolding methods for various spectra.The arguments formed in this article is clarified by concrete treatments for some typical examples.
    Solubilities and Activity Coefficients of CO2 in NaCl+15 Mass% Glucose-Water Mixture from 278.15 to 318.15K
    YUAN Chang-Bo, YANG Jia-Zhen
    1993, 14(1):  80-83. 
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    The solubilities and activity coefficients of CO2 at various molalities of NaCl in 15 mass% glucose- water mixed solvent were measured.And Henry coefficients and constant of salting-out were determined from 278.15 to 318.15 K.The temperature dependence of Henry coefficients for CO2 can be expressed as empirical quations lgS=A/T+B+CT, and the thermodynamic quantities of the solution process for CO2 were calculated.
    Preparation and Structure of [2,4-(CH3)2C5H5]2TiCO
    WANG Yue, LIU Ju-Zheng, FAN Yu-Guo, LIANG Ying-Qiu
    1993, 14(1):  84-88. 
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    [2,4-(CH3)2C5H3]2TiCOwas obtained by the reaction of [2,4-(CH3)2C5H3]2Ti with COat room temperature.The single crystal X-ray diffraction data of [2,4-(CH3)2C5H5]2TiCOwere collected and the crystal structure was solved by the heavy atom method.It belongs to orthorhombic system, space group P212121 with lattice parameters α=1.0078(5) nm, 6=1.1907(8) nm, c=l.1946 (5) nm, V=1.4337(13) nm3, Z=4.Several cycles of block matrix least-squares refinement gave the final R - 0.054.EHMOmethod has been used to calculate the electronic structure of [2, 4-(CH3)2C5H5]2TiCO.
    Reduction and Application of Normal Vibrational Models in Infrared Spectrum
    GUO Chun-Xiao, LIU Yue-Xian
    1993, 14(1):  89-92. 
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    The character of reducible representation for normal models of multi-atomic molecular system is formulated by group theoretical approach.The formula is programmed in IBMpersonal computer, which makes the reduction of normal models in infared spectrum simple and practical, The ine-ducible representation of normal models for some ABn(n = 2～12) molecules and carbon clusters Ca(w =-20, 24, 50, 60, 70, 84) are also presented.
    Studies on Preparation and Property of Positive Charged Montmorillonite
    WANG Yan-Qin, ZHANG Chun-Guang, HOU Wan-Guo, WANG Guo-Ting
    1993, 14(1):  93-96. 
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    The positive charged montmorillonite is prepared with positive mixed metal layered hydroxide deposited on montmorillonite by insertion reaction, it's highest ζpotential can reach +40 mV.The effect of temperature, concentration of Mg2+, pHand electrolyte on its ζpotential is studied.We consider that this positive charged montmorillonite has a characteristic adsorption on Al3+ and has no characteristic adsorption on Mg2+.The interaction between it's suspension and various valence anions is in agreement with Schulze-Hardy rule.
    Studies on Synthetic Bilayer Membranes Containing Naphthalene Chromophore
    LIU Chun-Jing, LI Guo-Wen, TIAN Yong-Chi, LIANG Ying-Qiu
    1993, 14(1):  97-101. 
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    Aseries of single-chain naphthalene containing amphiphiles, C.Naph(2,6)C4N+ (CH3)3 (n= 16,12,7,4), C12Naph(2,6)C4N+(CH3)2CH2CH2OHandC12Naph(2,6)PO4- were systematically synthesized.The aggregate morphology of the amphiphiles in dilute aqueous solution was observed by electron microscopy.The gel-to-liquid crystal phase transition of the bilayer membranes was studied by means of differential scanning calorimmetry(DSC).1H NMRresults of the aqueous bilayers are used to investigate the molecular motion in the membranes.The self-organization properties are discussed for the series of amphiphiles in dilute aqueous solution.
    The Effect of Solvent on Surface Enhanced Raman Scattering Spectra of Colloidal Silver
    HE Zhang-Fei, GU Ren-Ao
    1993, 14(1):  102-105. 
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    This paper reports the effect of solvent on the surface enhanced Raman scattering (SERS) spectra of colloidal silver, using2-aminobenzimidazole(BIMNH2) as a probe molecule.The absorption spectra indicate that the state of aggregation of colloidal silver is not alike in different solvents, the degree of dispersion of colloidal silver in different solvents always increases in the.order of C2H5OH, C2H5OC2H5, CH3OH, H2O, colloidal silver is more dispersed in CHCl3 than in CH2Cl2, CCl4, the latter two systems are almost the same.Different states of aggregation will give the different intensities of SERS.Experiment also indicates that the degree of dispersion of colloidal silver is always larger in mixed solvent than in single solvent.
    Effect of Alumina on Cu-based Catalysts Prepared by AHTD
    HU Yun-Hang, WAN Hui-Lin, TSAI Khi-Run
    1993, 14(1):  106-108. 
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    Effect of alumina on Cu-based catalysts prepared by aerosol high temperature decomposition was studied by different physicochemical techniques.The results show that alumina was dispersed at a high level in the catalysts, which made CuOcrystal grain dispersive and increased the catalyst surface area, the reaction activities from CO+H2 to methanol and stabilities against reoxidation.The surface enrichment of alumina was increased with the decrease of ZnO, but was not related with the concentrations of CuO.The content of Cu on the surface is nearly constant for a series of Cu/Zn/Al catalysts, i.e.Cu/(Cu+Zn + Al) = 16.4%.
    Studies on Synthesis and Catalytic Activity of Polymer-Bonded Chelated Titanate
    XING Bai-Jun, CHE Pei-Zhi, YAN Li, LIU De-Guang, KONG Xiang-Qiu
    1993, 14(1):  109-110. 
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    In this paper, a polymer-bonded chelated titanate was prepared by linking.The titanate can be.used to catalyze the esterification with a high yield, such as the preparation of di(2-ethylhexyl) ph-thalate, and can be reused 4 or 5 times.In addition, the relation between the structure of catalyst and the catalytic activity was also discussed.
    Fluorescent Spectrum of Polymethyl β-Phenethylsilylene
    CHEN De-Ben, PENG Li, ZHOU Ping
    1993, 14(1):  111-114. 
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    In this paper the excimer fluorescence of poly[methy(β-phenethyl) silyene] (PMPES) was studied.By concentration quenching, adding precipitant and quenching medium, the fluorescence of monomer and excimer in PMPESsolution is proved.The excimers originate from the interaction of interchain or intrachain phenyl groups.Through studying the fluorescence spectrum of PMPESat 77K, partial chromophores were found to form excimer' s conformation at ground state.
    Studies on the Absorbed Water in Some Amide Group Containing Ultrafiltration Membranes by FTIR, TGA and DSC
    DING Jun-Qi, YANG Jian-Ling, DING Ma-Tai, XIA Hai-Ping, HE Xu-Min
    1993, 14(1):  115-118. 
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    The stale of water in some ultrafiltraiion membranes with amide unit was investigated by using TGA, DSCand FTIR.Ultrafiltration membranes with amide group ran absorb water at room temperature.The absorbed water existed mostly as hydrogen bonded monomers, with a small proportion of dimers, trimers and higher oligomers, and would be almost dehydrated completely at 40℃.The amount of absorbed water per amide group varied in the order.polysulfone amide (PSA)> poly(benzimidazolone) (PBIL) > aromatic polyamide (APA), but the absolute amount of absorbed water varried in the order, APA>PSA>PBIL.
    Studies of the Ligand and Sodium Complex of Polysiloxanes with Liquid-Crystal Crown-Ether-Containing Side Chains
    ZHANG Shu-Yuan, ZHAO Yu-Bin
    1993, 14(1):  119-122. 
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    Anew ligand and sodium complex of poiysiioxanes with liquid-crystal crown-ether-containing side chain woe synthesized by the hydrosilyiation reaction using mesogenic monomer, 4-(allyloxy)-4' -(4' -carboxybenzo-15-crown-5)-α,to-diphenoxybutane and poly(methylsiloxane) with Cp2PtCl2 as catalyst.The liquid crystalline behavior of the monomer, liganci and complex was studied by DSCand polarized optical microscopy.It was found that they are thermotropic.
    A Study of ESR Spectra and Conformation of Propagating Radical in Bulk Polymerization Styrene
    MAO You-Gang, WANG Guo-Bin, ZHENG Ying-Guang, SHEN Jia-Cong
    1993, 14(1):  123-126. 
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    All the ESRspectra of propagating radical of styrene observed in bulk polymerization were studied and can be regarded as the superposition of the spectra of the two inner-rotational conformations of the radical A, B, which were obtained not only from the simulation of the spectra and the analysis of the hyperfine coupling constants, but also from the calculations of the conformation energy.The ratio of the conformation A/Bat the beginning stage of the reaction is 3, 0, being consistent with results coming from Boltzmann distribution.However the ratio gradually decreased with the polymerization and reached 0.2 at the end.The cause of the change has been discussed with respect to thermodynamics and dynamics.
    Molecular Weight Distribution in Grosslinked Polymers
    ZHANG Yi-Qun, CHEN Xin-Fang, TANG Ao-Qing
    1993, 14(1):  127-129. 
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    By using the methods of probability generating functions and Lagrange developing theorem, the molecular weight distribution of crosslinked polymers in which the initial molecular weight distribution is Flory distribution or Poisson distribution was derived.An information about the solubility of crosslinked polymers can be obtained from the distribution.
    Studies on Polymerization of α-Pinene Initiated by a New System AlCl3/Activator/Donors(Ⅲ)——Function of the SbCl3 Component in the System
    DENG Yun-Xiang, ZHANG Ren-Jun, LU Jiang, LIU Shi-Nan, Toshinobu Higashimura
    1993, 14(1):  130-134. 
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    In this study, we investigated the polymerization of α-pinene, the copolymerization of α-pinene/styrene and the isomerization reaction of a-pinene with the AlCl3/SbCl3 or AlCl3/SbCl3/EBsystem, in terms of the effects of SbCl3 component on the kinetics of the polymerization, the molecular weight, molecular weight distribution, and structures of the isomerization products.The results show that SbCl3 is necessary for the formation of higher oligomers, while to suppress the dimer formation.The a-pinene oligomers of relatively high molecular weight (q= 1140, Mw = 2590) were obtained in a good yield(>90 wt%), with a minimun contamination of the dimer(-5 wt%).On the other hand, the SbCl3 component achieved good results for promoting copolymerization of α-pinene/ styrene and reduction of isomerization product.
    Pervaporation Separation of Isopropanol/Water Mixture by the Chitosan Composite Membrane
    LI Wen-Jun, ZHENG Hua, TANG Ying
    1993, 14(1):  135-137. 
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    The chitosan composite membrane was prepared by pouring chitosan-HOAc solution ontothe polyacrylonitrile microporous supporting membrane.Pervaporation separation of azeotropic iso-propanol/water.mixture by this membrane indicates that the flux has an extremely increase than the crosslinking chitosan membrane and separation factor is considerably high.Meanwhile, both flux and separation factor enhance with temperature increasing, and more slowly decrease with isopropanol concentration increasing.
    The Kinetics of Glucose Oxidase Modified Polyaniline Electrode
    XUE Huai-Guo, MU Shao-Lin
    1993, 14(1):  138-140. 
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    The reaction rate-limiting of the glucose oxidase modified polyaniline(PAn/GOD) electrodeis controlled by an unsaturated enzyme kinetics with the rate constant of 1.43×10-7 m·s-1.According to the effect of pHon the maximum response current lgimax of the electrode, the plot of Ig imax, versus pHshows that two types of ionizing groups are involved in the intermediate of the reaction.The pK1c and pK2c are 4.9 and 6.3, respectively.When pK1c<pH<pK2c, the glucose oxidase has a high activity.The PAn/GODelectrode still remains a high activity after use of 1200 times and storing for 8 months.
    Studies on Synthesis of Glutathione Peroxidase Mimics and Its Catalytic Mechanism
    MA Wan-Chao, LUO Gui-Min, WANG Zong-Mu, HUANG Zhong-Li, YANG Tong-Shu
    1993, 14(1):  141-143. 
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    Four selenium-containing compounds were synthesized on the basis of the active site structure of glutathione peroxidase.These compounds indicated a higher activity of glutathione peroxidase than PZ51, which is known as the best mimic compound.Anew catalytic mechanism was proposed based on the chemistry and activity of these synthesized mimics.
    Synthesis and Kinetics of Chromogenic Substrates for Chymotrypsin
    ZHANG Ruo-Heng, GE Xue, XU Xiao-Jie, TANG You-qi
    1993, 14(1):  144-146. 
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    Five chromogenic substrates for chymotrypsin, P3-P2-Pl-p-NA (P1,P2,P3 = Phe, Leu, Ala, Pro, Asn) have been synthesized.The influence of amino acid on the specificity was given by kinetic analysis of the hydrolysis of the peptide by bovine chymotrypsin.Though most of the substrates are suitable to chymotrypsin, Ala-Ala-Phe-p-NAis the best.
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