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    24 July 1993, Volume 14 Issue 7
    Articles
    The Preparation of Ultrafine Monodispersed Colloidal Particles of Rare Earth Compounds
    DENG Hong-Mei, XU Yan, KU Yih-Tong
    1993, 14(7):  889-892. 
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    Aseries of ultraf ine monodispersed colloidal particles of rare earth compounds were obtained by urea decomposition.The effects of various parameters, such as concentration, pH, aging temperature and time, and the nature of anions on the resulting precipitate particles were studied systematically.The optimal preparation conditions for the corresponding REparticles were concluded and discussed in detail.Powders obtained all had a relative large BETsurface area, which are more than 29 m2/g.
    Studies on the Synthesis, Structure and Properties of Zinc Silicoaluminophosphate Molecular Sieve
    HAN Shu-Yun, CHE Zhi-Yan
    1993, 14(7):  893-896. 
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    The pure zinc silicoaluminophosphate molecular sieve (ZnAPSO-5) was synthesized in the presence diethylaminoethanol as a template by hydrothermal crystallization.The chemical composition and parameters of the unit cell of ZnAPSO-5 were determined.The structure of ZnAPSO-5 has been studied by means of X-ray diffraction analysis, scanning electron microscopy, infrared spectra, X-ray photoelectron spectroscopy (XPS).The thermal stability and surface acidity of ZnAPSO-5 were investigated.The results showed that the atoms of zinc and silicon entered into the framework of ZnAP-SO- 5 molecular sieve and that isomorphous replacements of aluminium by zinc and phosphorus by silicon make the framework carry negative charge but it has been balanced by H+.Therefore, ZnAPSO-5 exhibits the property of Bronsted acid.
    Studies on Synthesis, Crystal Structure and Kinetics of Thermal Decomposition of o-Vanillin Ethylenediamine Nickel (Ⅱ)
    LIU De-Xin, LI Shu-Lan, GUI Xue-Gui, LI Xiao-Yan
    1993, 14(7):  897-901. 
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    The crystal of o-vanillin ethylenediamine Nickel (Ⅰ) (Ni-Vaniethy) C18H18N2NiO4·H2Owas synthesized and its structure was determined by single crystal X-ray diffraction method.The complex belongs to the orthorhombic system, space group Pbna with cell parameters of a=1.1931(3) nm, b=1.5233(4) nm, c=1.9592(6) nm, V=3.561 (nm)3, M=403.08, Z=8, Dc=1.50 g/cm3, μ-11.23 cm-1, F(000)=1680, final R=0.071 for 1200 unique reflections [I≥3(σ)].The kinetics of thermal decomposition reaction of the complex was studied under a non-isothermal condition by TG.The kinetic parameters were obtained from the analysis of TG, DTGcurves by integral and differential methods.The functions of thermal decomposition reaction mechanism are:f(a)=2(1-a)1/2,g(a)=1-(1-a)1/2.
    Structural Studies on Partially Disordered Layer Lattice of Zirconium Pillared Montmorillonite
    WANG Jun, WANG Lian-Bo, JIANG Qing, LI Hong, XIANG Si-Fen, LIN Bing-Xiong
    1993, 14(7):  902-906. 
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    The structure of pillared montmorillonite is the partially disordered layer lattice.Its basal spacings can be expanded to many possible values with different probabilities depending on the type and structure of the pillars.If a formula describing the X-ray diffraction intensity of partially disordered layer lattice as a function of basal spacings and the corresponding probabilities is computationally simulated with the experimental XRDpattern, the basal spacings and probabilities can thus be obtained.In this paper, zirconium pillared montmorillonite samples were prepared.The simulated results show that the basal spacings are expanded to 2.55 nm, 2.10 nm and 1.26 nm with probabilities of 35%, 2.7% and 38% corresponding to [Zr4(OH)8(H2O)16]8+, [Zr3(OH)4(H2O)5]8+ ions together with some adsorbed water molecules and H2Oas the main pillaring species in the interlamellar regions, respectively.The experimental results obtained from CBC, ICPetc.are applied to calculating the distribution of the pillars in the interlayer zone.The fashion of the connection between pillars and unite layers is also given.Subsequently, a three-dimensional statistical structural model is built up.The agreement of the pore-volume between the theoretical calculation and experimental result verifies the rationality of the structural model.Therefore, the basal spacing characterized by d001 which is calculated from Bragg e-quation is not exact actually.
    Investigation of the Role of Lanthanum Ions in LaDAlY Zeolites with 29Si, 27Al MAS NMR
    FU Jun, BAO Shu-Lin, XU Qin-Hua, HU Cheng
    1993, 14(7):  907-910. 
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    The influence of lanthanum ions on the framework silicon, aluminum and extra-framework aluminum of LaDAlYzeolites has been studied by using29Si, 27Al MAS NMRand static 27Al NMRwith acetylacetone treatment.The results show that the chemical shifts and peak profile depend not only on the number of [AlO4]- tetrahedra connected to [SiO4] tetrahedra, but also on the amount of exchanged lanthanum ions.It was also found from 27Al MAS NMRthat the introduction of lanthanum ion makes the peak profile of framework aluminum broadening and asymmetrical.In addition, the effect of lanthanum ions on extra-framework aluminum in LaDAlYzeolites was discussed.
    Partial Least-Squares Method for Measuring of Coexisting Terbium, Gadolinium and Erbium
    GUO Chun-Xiao, DUAN Yi-Xiang, DAI Guo-Zhong, JIN Qin-Han, GUO Chun-Bao
    1993, 14(7):  911-913. 
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    Partial least-squares method is applied in quantitative determination of multi-component mixture of rare earth by UVspectrophotometry.The accuracy of calculation is studied by changing the ranges and intervals of wavelength.The results show its superiority to other numerical methods.
    Determination of Catecholamines by Catalytic Oxidation at 1:12 Molybdophosphate CME in Liquid Chromatography
    JIN Li-Tong, LIU Tong, ZHOU Man-Shui, FANG Yu-Zhi
    1993, 14(7):  914-917. 
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    An electrode modified with 1:12 molybdophosphate (PMo12 CME) was prepared.Its high electrocatalytic effect on the oxidation of catecholamines (noradrenaline(NE), adrenaline (E) and dopamine(DA)) was described, and the mechanism was discussed.LCECwith PMo12 CMEwas used to separate and detect catecholamines.The linear range of detection is 8.0×10-11-2.0×10-8 mol for NEand DA, 4.0×10-11-2.0×10-8 mol for E.The detection limit is 4.0×10-11 mol for NEand DA, 2.0×10-11 mol for E.The relative standard deviation for seven parallel determination is 1.6% for NE, 2.1% for DAand 4.5% for E.The noradrenaline in rat brain was detected and the results are satisfactory.
    Studies on the Improving Iterative Target Transformation Factor Analysis
    SHEN Han-Xi, CAl Shuo-wei
    1993, 14(7):  918-921. 
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    Anew method of factor analysis called improving iterative target transformation factor analysis (IITTFA) has been proposed.Making use of the iteration and target transformation of normal projection matrix to concentration target vector could avoid the course of inversion in general factor analysis and decrease possible amplification of experiment errors.Application of the nonlinear iterative partial least squares method (NIPLS) to solve the data matrix could simplify the procedure of general factor analysis.The method was used to assay the amounts of acetylsalicylic acid, P-acetamidophenol and caffeine containing in complex tablet of P-acetamidophenol.The average recoveries were 99.4%-100.6%.
    The Cation Exchange Eastman-AQ Polymer Film Modified Carbon Fiber Electrode and Voltammetric Behavior
    TIAN Min, DONG Shao-Jun
    1993, 14(7):  922-926. 
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    Acarbon fiber electrode modified with Eastman-AQpolymer film was successfully prepared, effects of some experimental parameters were assessed.The behavior of (Ru(NH3)63+ and MV2+(methyl viologen) were investigated by cyclic voltammetry.AQ-55Dmodified microelectrode possesses high stability, selectivity and sensitivity, the linear ranges of Ru(NH3)63+ and MV2+ are 1.2 ×10-6- 1.2×10-5 mol/Land 1.7×10-6-1.4×10-5 mol/L, and the correlation coefficients are 0.999 and 0.998, respectively.Diffusion coefficients of some ions in the film were determined by chronoamperometry at AQcoating microdisk electrode.
    Investigations on Nanometer-Sized Ultramicroelectrodes(Ⅰ)——Fabrication, Characterization and Application of Ultramicrobandelectrode
    ZHANG Xue-Ji, ZHANG Wu-Ming, ZHOU Xing-Yao, WANG Zu
    1993, 14(7):  927-9301. 
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    The present paper reports the investigation and application of nanometer-sized gold band ul-tramicroelectrodes.The surfaces of the electrodes are revealed by scanning tunneling microscopy (STM), scanning electron microscopy(SEM) and X-ray photoelectron spectrum(XPS) respectively.Cyclic voltammetry and chronoamperometry are employed to characterize the electrodes.Diffusion model of hemicylinder microelectrode is employed to describe the diffusion behavior of ultramicroelec-trode whose band width is as small as 50 nm and the results obtained are satisfactory.Both theory and experimental results show that decrease of the band width has little effect on the faradic current at the ultramicrobandelectrodes, however, the non-faradic current is proportional to the area of those electrodes.So the higher signal to noise ratios are expected to obtained at those electrodes.Potassium fer-rocyanide is detected at 50 nm band ultramicroelectrode with 5.0×10-7 mol/Ldetective limit.
    Studies on Lithium Ion-selective Photodiode Based on Neutral Ionophores and Application in Blood Serum
    HUO Xi-Qin, WANG Ke-Min
    1993, 14(7):  931-934. 
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    Optical chemical sensors are becoming increasingly popular and a multitude of designs have been reported recently.All these devices rely on a light source and a detector.Optical fibres are often employed to bring the incident light to the detector.Spectral selectivity is achieved conventionally using monochromators.Here we report on a compact probe that consists of a photodiode coated with a poly (vinyl chloride) (PVC) sensitive membrane and a light emitting diode having a relatively narrow spectral output.The two diodes are embedded in a plastic barrel opposite each other and the photodiode can be dipped into solutions similar to an ion-selective electrode.ETH1810 and ETH 2439 were chosen as the lithium ion carrier and pHindicator, respectively.The ETH2439 shows an absorption band at 514 nm in the unprotonated form which changes to about 650 nm when protoned.The competitive binding of lithium ion and hydrogen ion will change the color of the PVCmembrane.The red light emitting diodes have a maximum output at 660 nm, so that the change can be adequately monitored.The sensor shows a linear response to lithium ion over the range of 1×10-4-7.9 × 10-2 mol/Lwith the same selectivity as in potentiometric system.By use of the standard-addition method, different serum samples containing Li+ in the clinical range were assayed with this photodiode sensor.
    Studies on Deposition of Cobalt Thin Film by Surface Wave Excitation Microwave Plasma Dissociation of Co(CH3COO)2
    YU Ai-Min, LI Quan-Zhong, JIN Qin-Han
    1993, 14(7):  935-936. 
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    Using a low-powered microwave generator and a Surfatron discharge cavity, cobalt filmswere synthesized on silica glass substrates from hydrogenolysis of Co(CH3COO)2 by Ar microwave plasma surface wave excitation.In addition, the chemical behavior of atomic hydrogen on the formation of cobalt film was studied and discussed.
    Study on Factors Influencing Characteristic Mass in Graphite Furnace Atomic Absorption Spectrometry
    ZHENG Yan-Sheng, SU Xing-Guang, QUAN Zhe
    1993, 14(7):  937-939. 
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    Measurements of characteristic masses for Ag, Cd, Cr, Ga, Ge and In have been made over broad temperature intervals.The experimental results show that the values of m0 have appeared to be better than 10% -15% when the analytes are atomized in temperature intervals studied.Influences of atomization temperatures on the ratio m0[cmlc.]/m0[exp.] were studied when the analytes were e-vaporated from the wall, using the platform and the V-shaped boat techniques.For Ag and Cd the ratio m0[cmlc.]/m0[exp.] does not change significantly in the temperature intervals studied.However, for the remaining four elements (Cr, Ga, Ge, In) the ratio m0[cmlc.]/m0[exp.] varies with temperature.The ratio m0[cmlc.]/m0[exp.] of In or Ge was increased obviously in the presence of matrix modifier.
    Studies on the Reaction of Diethoxyisocyanatophosphine with Benzalanilines
    YANG Hua-Zheng, LU Jian-Bin
    1993, 14(7):  940-943. 
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    Two kinds of compounds were synthesized by the reaction of diethoxyisocyanatophosphine with benzalanilines depending at the different positions of substituents attached to the benzene ring.When there was no substituent or the substituent was at m-, or p-position, the normal 1,3-dipolar cy-cloaddition took place to yield a stable compound 2, 1,3,4-diazaphospholidene, through a rearrangement of ethyl from Oatom to Natom.The effects of the reaction temperature and solvent were investigated and the diastereoisomers of compound 2 were separated by TLC.However, when the substituent was at o-position, compound 5, a-anilino phosphonate was obtained under the same experimental conditions.Aconclusion might be drawn that the steric hindrance effect of the ortho substituent block the cycloaddition and the intermediate was hydrolyzed by the moisture.Elementary analysis, 1H NMR, IRand MSspectra confirmed the structures of the compounds.
    Synthesis of Derivatives of Amidophosphoric Esters Containing Hydroxyphenyl or Aminophenyl Group
    CHEN Ru-Yu, AN Feng-Long, BAI Ming-Zhang, SUN Li-Juan
    1993, 14(7):  944-946. 
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    Six derivatives of amidophosphoric esters containing hydroxyphenyi or aminophenyl group were synthesized by a homogeneous reaction.The products.[(ClCH2CH2)2NP(O) (OPh) (XArY)] (X:O,NH; Y:m or p-OH, NH) were confirmed by elemental analysis and IR, 1H NMR, MSspec-trometry.
    Studies on Condensed Heterocyclic Compounds (Ⅻ) ——Synthesis and Crystal Structure of 3(1-Naphthylmethylene)- 6-hexyl-s-triazolo[3,4-b]-1,3,4-thiadiazole
    ZHANG Zi-Yi, LI Ming, ZHAO Lan, WANG Hong-Gen, WANG Ru-Ji, LI Zheng-Ming, LIAO Ren-An
    1993, 14(7):  947-950. 
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    3(1-Naphthylmethylene)-6-hexye-s-triazolo[3,4-b]-1,3,4-thiadiazole was synthesized by condensation of 3(1-naphthyl-methylene)-4-amino-5-mercapto-1,2,4-triazoIe with n-heptanoic acid in the medium of phosphorus oxychloride.The single crystal structure of this new compound was determined by X-ray analysis.The crystal belongs to monoclinic system with a space group C2/C, a=2.8680(6) nm, 6=0.8356(2) nm, c=1.6578(3) nm, β=114.19(2)°, V=3.624 nm3, M=350.49, Z=8, Dx=1.29 g/cm3, U=1.80 cm-1, F(000)=744, R=0.071.The most important information obtained from analyzing the crystal structure is that, in comparision with normal N-N, C-Nand C-S, each of the single bond lengthes of N(23)-N(24), C(22)-N(26) and C(25)-Sin this compound is smaller than the normal bond length, but those for all C=Nbond show remarkable lengthening effect of 0.003 nm(2.3%).All the above results indicate that the s-triazolo [3,4-b]-1,3,4-thiadiazole is planar, confirming the atom character of 10-π electron system.
    Studies on the Chemical Constituents of Red Algae Peyssonnelia caulifera
    SU Jing-Yu, YANG Xiao-Shuang
    1993, 14(7):  951-953. 
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    The chemical constituents of red algae Peyssonnelia caulifera have been further studied.Anew glycolipid, 3-hexadecylcarbonyloxy-2-(11Z)-eicosylcarbonyloxy glycerol 1-β-D-galatoside, along with four known compounds was isolated.They were identified as saringosterol, fucosterol, glycerine- 1-monopalmitate and octadecyl heneicosanate.
    Pattern Recognition for the Antitumour Activity of Some Fluorescein Derivatives
    LI Bing-Rui, HE Feng-Ying, WANG Liu-Fang
    1993, 14(7):  954-956. 
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    In this paper, some antitumour fluorescein derivatives were classified according to their activity using Non-Linear Mapping (NLM) pattern recognition techniques.Three sets of structural parameters, {ΣMR, F2, (Σ)2}, {ΣMR, F2, π3} and {ΣMR, ΣF, (Σπ)2} were screened out.The results showed that the main structural factors influencing the antitumour activity of these substances are their molar refraction, hydrophobicity and field inductive effect, especially field inductive effect of 2-substituent, whereas conjugative effect is not.The forecast model about antitumour activity of the derivatives were established and further syntheses were suggested by this research.
    Stereoselective Syntheses of Glycopyranosyl 2-phenyl- 1,2,3-triazole-4-carboxylates and (4,6-Dimethylpyrimidin-2-yl)1-thioglycopyranosides
    YU Jian-Xin, LIU Fang-Min, CHI Xiao-Jun, CAO Ling-Hua
    1993, 14(7):  957-959. 
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    The glycopyranosyl 2-phenyl-1, 2, 3-triazole-4-carboxylates (1 - 9) and (4, 6-dimethylpyrimidin-2-yl)1-thioglycopyranosides (10-13) were obtained with high yields and stereos-electivity from the reaction of glycopyranosyl bromide with sodium 2-phenyl-1, 2, 3-triazole-4-car-boxylate or with 2-mercapto-4, 6-dimethylpyrimidine sodium salt by phase-transfer catalysis under facile conditions.The structures and confagrations of the products were confirmed on the basis of optical rotations, IRand 1H NMRspectral data.
    Studies on Stereospecific Binding of D- and L-Tryptophans to Bovine Serum Albumin
    ZHANG Bao-Lin, YANG Zhi-Wei, WANG Wen-Qing
    1993, 14(7):  960-962. 
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    The binding of two enantiomeric tryptophans(D-,L-Trp) to bovine serum albumin (BSA) has been studied using centrifugal ultrafiltration and circular dichroism spectroscopy.The binding data are analyzed according to the model of specific and non-specific sites, and the hinding constants are obtained.The primary binding site is shown to have higher affinity for L--Trp(1gK,=5.14 L/mol), as compared to that for D-Trp(K,- 0).CDspectrum measurements also provide evidence for this stereospecificity.The pHdependence of K, indicates that the affinity increase with increasing of pHand reaches maximum near pH 9.0, this finding is explained by the N-Bconformational transition model of albumin.The results are discussed in terms of an allosteric domain model where in the indole ring embedded in the hydrophobic interior of domain Ⅱ as a strong point of attachment at the binding site, the carboxyl and amino groups are still exposed in the hydrophilic exterior and interact electrostatically with the basic and acidic side chains of the protein placed around the opening of domain Ⅱ.
    Synthesis of N,N-bis(2-chloroethyl) Fructopyranosyl- phosphoramidates and Their Antitumor Activities
    CHEN Ru-Yu, CHEN Xiao-Ru
    1993, 14(7):  963-965. 
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    In this paper, a series of new N, N-bis(2-chloroethyl) fructopyranosyl phosphoramidates were synthesized by the reaction between phosphorus oxychloride and 2,3:4,5-di-O-isopropylidene-Dructopyranse(1).The structures of all compounds prepared were determined by 1H NMR, IRand elemental analysis.The existence of diastereoisomers were proved by 31P NMR, but only one pure iso-mer was isolated by recrystallization.The results of preliminary biological tests indicated that the title compounds had the inhibition effect against L1210 cells and 5-180 tumors.
    Aggregation of Sodium Deoxycholate in Aqueous Solution
    JIANG Yun-Bao, HU Jing-Song, XU Jin-Gou, HUANG Xian-Zhi
    1993, 14(7):  966-970. 
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    The aggregation behavior of a steroidal surfactant--sodium deoxycholate (SDOC) inaqueous solution was studied by extrinsic fluorescent probe [via twisted intramolecular charge transfer (TICT) fluorescence characteristics of p-N,N-dimethylamminobenzaldehyde, DMABA], optical rotation, conductivity, and pHmeasurement.TICTfluorescence band of DMABAshifts to blue and the fluorescence intensity ratio (Ia/Ib) of TICTband to LEband increases with the increase of SDOCconcentration up to 6.0× 10-3 mol/L, then the variation trends reversed.These results indicate that the critical micelle concentration of SDOCis 6.0×10-3 mol/Land that the SDOCmolecules don't exist in monomer but in dimer which provides a hydrophobic microenvironment less polar than that of SDOCmicelle.Fittig the conductivity data of aqueous SDOCsolution yields an average aggregation number of 8-10 for SDOCmicelle which is substantially less than that of normal micelle.Optical rotation and pHmeasurements show that SDOCmicelle has a relatively lower symmetry and stronger basicity than the dimer.
    A Study of the Heat Treatment Process of Titanium Oxide Xerogels
    LIU Shuang-Huai, ZHOU Gen-Tao, PENG Ding-Kun, ZHOU Gui-En, JIA Yuh-Bo, LU Bin
    1993, 14(7):  971-974. 
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    In this paper, we investigated the calcined process of titanium oxide xerogels, which were prepared in the nonpolar solvents (C6H6, CCl4) by sol-gel method at different heat rate in O2 atmosphere.The phase composition and structure, the particle shape, size and distribution of the derived titanium oxide ultrafine powder were analyzed by differential thermal analysis, thermal gravimetry, FT-IRspectra, X-ray diffraction and transmission electron microscope.The possible mechanism of phase transition was given in terms of grain size varing with annealed temperature.
    Ab initio Studies on Icosahederal Molecules (Ⅲ) ——The Electronic Structure of Sc13
    ZHANG Ming-Yu, YU Wei-Zhou, LI Xiao-Tian, JIANG Yuan-Sheng
    1993, 14(7):  975-977. 
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    In this paper, ab initio calculations on Sc13 are performed based on the symmetry reduction of icosahedral group.The ground state configuration is ag2t1M6hg10ag2gM8t2M6t1M5,2T1u, which is in agreement with the ESRexplanations.The calculated results indicate that during the formation of the Sc13 the Sc atoms undergo an s-d electron excitation, i.e., from filled 4s shells to unfilled 3d shells, so 4s and 3d electrons all play an important role in the bonding.The bond energy Sc13 can exist stably.The reasonable choice of the contracted degree of the used basis set is very important to describe wavefunction of Sc13.
    Anodic Oxide Film In2O3 (Ⅰ)——Preparation and Electronic Properties of the Film
    LIN Zhong-Hua, LUO Jin, CHEN Hai-Yi, TIAN Zhao-Wu
    1993, 14(7):  978-982. 
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    The electrode reactions of indium in alkaline solution have been studied by using cyclic voltammetry and XPStechnique.The results show that the In2O3 film can be obtained by means of the anodic oxidation.The preparation methods were optimized in order to form an In2O3 film with high quantum efficiencies for the photoelectrochemical oxygen evolution.The semiconducting properties of the In2O3 anodic film and the thermally oxidized In2O3 anodic film were investigated through Mott-Schottky plots, photocurrent response and spectra, and electroreflectance spectra.The anodic film possesses the two kinds of donor and the indirect fundamental optical transition (Eg=2.88 eV) which becomes direct (Eg=3.68 eV) after thermally oxidation of the film.
    A Study of the Influences of CH2Cl2, CHCl3, CCl4 on the PE Liquid Crystal Structure by Means of SAXS
    SUN Run-Guang, ZHANG Jing, QIANG Zhi-Jun, WANG De-Hua, WANG Zi-Hao
    1993, 14(7):  983-987. 
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    In this paper, the influences of CH2Cl2, CHC13 and CCl4 on the liquid crystal structure of phosphatidythanolamine(PE) have been investigated by using the method of SAXS (the small angle X-ray scattering) respectively.The experimental results show the structure of the PEliquid crystal phase is primarily influenced by space-spinning electronic cloud density distribution of CH2Cl2, CHCl3 and CCl4.The compounds whose space-spinning electronic cloud density distribution assumes spinning oval ball in shape give the mechanism that makes the PEliquid crystal state to form hexagonal Iphase; The compounds whose space-spinning electronic cloud density distribution assumes spinning taper in shape give the mechanism that makes the PEliquid crystal state to form cubic-hexagonal phase.The compounds whose space-spinning electronic cloud density distribution assumes spinning ball in shape give the mechanism that makes the PEliquid crystal state to form lamemller-cube phase.
    Preparation and Characterization of Organic Surperlattice-type Structure
    JIANG Lei, WANG De-Jun, LI Tie-Jin, YANG Jun, WANG Rong
    1993, 14(7):  988-991. 
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    Adetail investigation for organic surperlattice-type structure which was prepared at room temperature by using LBmethod was carried out.The techniques used for characterization of the structure include IRpolarized spectroscopy, UV-Vis polarized spectroscopy and low-angle X-ray diffraction.On the other hand, a grating modle was used to calculate the peak position of the X-ray diffraction and the results fit the experiment very well.
    Phase Diagram of Binary Systems ErCl3-MCln (M=Li, Ca, Pb; n=1 or 2)
    ZHENG Chao-Gui, HUANG Shou-Lin, WANG Si-Qiang
    1993, 14(7):  992-995. 
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    The phase diagram of binary systems ErCl3-MCln(M=Li, Ca, Pb; n=1 or 2) were investigated by means of DTAand X-ray diffraction analysis.It was found that ErCl3-LiCl system is of peritectic type with compound Li3ErCl6 and its phase transition at 466℃ as well as the invariant points e 40.0 mol(%) ErCl3(479℃) and p 31.0 mol(%) ErCl3(522℃).ErCl3-CaCl2 and ErCl3-PbCl2 systems are of the simple eutectic type with eutectic points 46.0 mol(%) ErCl3(578℃) and 38.0 mol (%) ErCl3(405℃) respectively.An unstable compound, formed in the solid state, is PbErCl5 and decomposes at 356℃.Some rules of phase diagram were explored.
    Structural Information of Nitrogenase Active-Center Clusters Deduced from EHMO Study
    LIU Ai-Min, ZHOU Tai-Jin, WAN Hui-Lin, TSAI Khi-Rui
    1993, 14(7):  996-999. 
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    Structural models for the nitrogenase FeMo-cofactor based upon the crystallographic analysis of the nitrogenase MoFe-protein were studied by means of the improved method of EHMOcalculations, where the interest was focused on the unknown ligand Yof the Ree's model.The results gained from cases of Y=S, N,O, C, Hand H…Hsuggested that the ligand Ywas very like O (model I0 and model X).Aprobable hydrogenation mechanism (model L) was eventually proposed and discussed in the present paper.
    Valence Bond Approach to the Ground and Electronic Excited States of H3+
    WU Wei, MO Yi-Rong, ZHANG Qian-Er
    1993, 14(7):  1000-1003. 
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    In the present paper, the ground and several low-lying excited states of H3+ were discussed by using the bonded tableau approach for valence bond theory, and the features of valence bond structures of H3+ were studied.It has been obtained that the geometries of H3+ at the ground and the first excited states are equilateral triangular and linear, respectively, For the ground state, the bond length is 0.08752 nm, which is in agreement with previous results.The first excited state is a bound state and can be described by three resonance structures.The second and the third excited states prefer isosceles triangular and are near-degenerate, however they are not stable states and are the products of the very weak interaction between H2+ and H.
    Covalence of Be in Dimethylberyllium
    YI Xiang-Hui, LI Le-Min, XU Guang-Xian
    1993, 14(7):  1004-1007. 
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    The study on the covalence of Be in dimethylberyllium has been undertaken with the method of natural bond orbitals(NBO) on the basis of the new definition of covalence proposed by XU Guang-xian, and the results are reported in this paper.Through the analysis of the eigenvalues and eigenvectors of the submatrices related to proper fragments of the monomer, dimer and polymer of dimethyl-beryllium, it is found that there exists three center-two electron dative bond between the bridge methyl and beryllium atoms whereas there is not dative bond between the terminal methyl and beryllium atom, thus the covalences of Be in monomer, dimer and polymer of dimethylberyllium are 2, 4 and 6 respectively.
    Ab Initio Studies on IRC and Rate Constants for the Reaction of Atomic Hydrogen with Acetylene
    FANG De-Cai, FU Xiao-Yuan
    1993, 14(7):  1008-1009. 
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    The Intrinsic Reaction Coordinate (IRC) for the titled reaction was traced by means of HF/ 6-31G.The reaction activation energy is 105.9 kJ/mol(PUMP3/6-31Genergy barrier+ HF/6-31Gzero-point energy correction).The reaction rate constants calculated by CVTand tunneling effects are obtained by small-curvature method(SCSA.G).
    A Study of Structure of Intercalate Inclusion Compound of Cedrol with o-Cresol
    GUO Wen-Sheng, LU Yang, WANG Shu-Chun, ZHENG Qi-Tai
    1993, 14(7):  1010-1012. 
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    The analysis of crystal structure of inclusion compound of cedrol and o-cresol shows it belongs to monoclinic system with a space group P21, a=0.5598(1) nm, b=1.8882(1) nm, c=0.8983(3) nm, β=104.78(1)°, V=0.98297(36) nm3, Z=2 and R=0.0662.It has been found that the inclusion compound is composed of cedrol and o-cresol with a molar ratio of 1:1.In the crystalline, the molecules of o-cresol pack in the layers were formed by the cedrol molecules in a good order, and form intercalate inclusion compound.The O(1)-- O(2) value between the hydroxyls of cedrol and o-cresol is 0.2705(11) nm.While crystal data of cedrol are as follows, orthorhombic, space group P22121, a=1.1282(4) nm, 6=1.5656(3) nm, c=1.5927(4) nm, V=2.61362 (136) nm3, Z=8 and R=0.0852.The O(1)--O(2) value between the hydroxyls of cedrol is 0.2795(19) nm.The hydrogen bonding of intercalate inclusion compound in crystalline is 0.0090 nm shorter than that of cedrol, it shows that hydrogen bonding seems to be important in the formation of stable intercalate inclusion compound.
    Preparation of Ultrafine Monodispersed Hematite Hydrosol Partieres by Forced Hydrolysis in Boiling Reflux State
    KAN Shi-Hai, ZHANG Yan, PENG Xiao-Gang, LI Shou-Tian, XIAO Liang-Zhi
    1993, 14(7):  1013-1014. 
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    Spherical and cubic monodispersed hematite colloidal particles (30, 40 and 65 nm) were prepared by forced hydrolysis of acidified solutions of FeCl3.The reaction system is dynamic and open to increase the relative motion speed between the solute ions and the nuclei.The shape and size of the particles depend on the experimental conditions.The particles were characterized by TEMand XRD.
    Determination of the Exchange Capacities of Snake-cage Resin
    ZHU Chang-Ying, DENG Huan, WANG Li-Yan, YAN Liang-Zeng, LI Lian-Rong, YANG Xiu-Lin, QIAN Ting-Bao
    1993, 14(7):  1015-1018. 
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    Snake-cage resin is a kind of amphoteric resin with special structure.Because of its unique retardation ability and its advantage of water regeneration it has been used in many ion separation processes.In this article, the author described the structure of snake-cage resin and the mechanism of ion retardation proposed a new concept, ion retardation capacity, to estimate the snake-cage resins.Then the determination of residual anion exchange capacity, residual cation exchange capacity, total anion exchange capacity, ion retardation capacity and total cation exchange capacity were studied.Finally, the determination of these capacities for Retardion 11A-8 and nine other snake-cage resins synthesized by the author was carried out.
    Determination of the Initiating Active Species of Plasma Initiated Polymerization by Gas Chromatograph/Mass Spectrometry
    MA Yu-Guang, GUO Hai-Chen, YANG Mei-Lin, SHEN Jia-Cong
    1993, 14(7):  1019-1022. 
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    In a high concentration of chain transfer agent ethanethiol, the GC-MSanalysis of oligomers obtained by the plasma initiated polymerization of liquid monomers permits identifying and determining all compounds formed in the early propagation steps.From its analytical data the exactstructure of the starting chain end could be obtained, and allowed a more detailed description of theinitiating active species which is the ester group(这里有图片19930737-1019-1.gif) being produced by the monomer split-ted in plasma zone.
    The Synthesis of Some Polymeric Diethylenetriamine/Cu(Ⅱ) Complexes Supported by Porous Crosslinked Poly (methyl Acrylate) and Their Sorption Properties for Urea
    HE Bing-Lin, MA Jian-Biao, ZONG Fang
    1993, 14(7):  1023-1027. 
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    Some polymeric diethylenetriamine/Cu(Ⅱ) complexes supported by porous crosslinked poly (methyl acrylate) were synthesized as the adsorbents for urea and their properties in adsorbing urea were studied.The results showed that the polymeric complexes adsorbed urea through coordinate bond of urea to the centric ion.The largest capacity of the complexes was determined as 71.5 mg/g when the adsorption was performed at 28℃ in the urea solution with concentration of 130 mg/dLin a buffer of NaH2PO4-Na2HPO4(pH=7.0).
    Synthesis and Phase Behavior of Liquid Crystalline Polysiloxanes with Azobenzene or Azoxybenzene Mesogens in the Side Chains
    LUO Zhao-Hui, ZHUO Ren-Xi, ZHANG Xian-Liang
    1993, 14(7):  1028-1032. 
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    In this paper we report nine polysiloxanes with azobenzene or azoxybenzene mesogens in the side chains.Polysiloxanes Ⅲa-f were synthesized by reacting poly (3-chlorocarbonylpropyl)methyl-siloxane-co-dimethylsiloxane with 4-(4'-substituted phenylazo)phenol or 3-methyl-4 (4'-substituted phenylazo)phenol in 74%-81% yields.By the oxidation of Ⅲa-c,polysiloxanes Ⅲa-c were further prepared.The chemical structures of these polysiloxanes obtained were confirmed by IR,1H NMRand elemental analysis.Their phase behavior were investigated using differential scanning calorimeter (DSC) and polarizing microscope.Six of them, Ⅲa-c and Ⅲa-c,show liquid crystalline properties.
    Synthesis of PMMA-PEA-PAN Block Polymer by Group Transfer Polymerization
    XIA Hai-Ping, CHEN Ping, GUO Jian, DING Ma-Tai
    1993, 14(7):  1033-1034. 
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    Aseries of PMMA-PEA-PANblock copolymers were synthesized by means of group transfer polymerization (GTP) and using dimethyl ketene methyl trimethylsilyl acetal as initiator and n-Bu4NH (PhCO2)2 as catalyst.The terpolymers were characterized by GPCand 1H NMR.