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Table of Content

    24 January 2002, Volume 23 Issue 1
    Articles
    Species of Rare Earth in Rat Liver
    LU Ran, ZHU Yan-Mei, CHEN Hang-Ting, ZHAO Da-Qing, NI Jia-Zuan, CHEN Dong, NIE Yu-Xiu
    2002, 23(1):  1-5. 
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    The metabolic accumulation and species of rare earth in rat liver were investigated by ICP-MS and chromatography after the rats were fed by a low dose of mixed rare earth for a long time or the administration of a high dose of lanthanum for a short time. It was found that the content of rare earth in the liver increased with the arising of dose of drug delivery. Their accumulation rate was different, for example, La>Ce>Nd>Pr. The protein which could combine with rare earth specially were not gotten through chromatography. It was suggested that rare earth could bind to many proteins voluntarily, such as some important enzymes and it might be separated from the combined proteins under certain conditions.
    Effects of Pressure, Temperature and Grain Size on Synthesis and Structures of Fe-N Alloys
    LIU Li, YAO Bi, ZHAO Xu-Dong, GUO Xing-Yuan, NING Fan-Long, SU Wen-Hui
    2002, 23(1):  6-9. 
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    Effects of pressure, temperature and grain size on the solid state reaction between α-Fe and amorphous BN and crystal structures of the resultant of the reaction were studied by using mechanical milling and high pressure techniques at the temperatures ranging from 580 to 930 Kunder pressures between 1×10-3 Pa and 4 GPa. It was found that the pressures and refinement of grain size can greatly accelerate the solid state reaction process. There is a critical grain size for α-Fe, below which the reaction begins to occur. In the present experiment, this grain size was measured to be about 8 nm. The crystal structures of the resultants change with the variation of pressure and temperature. A new Fe-N alloy with orthorhombic structure was produced firstly at 2 GPa and 800 K. Single phase ε-FexN alloy can be obtained in the temperature range of 690 to 800 Kat the pressures of 3 to 4 GPa. However, the resultant is not any Fe-N alloy but Fe3Balloy when the pressure is 4 GPa and the temperature is above 930 K.
    Phase Equilibrium Properties of Supercritical Carbon Dioxide in Binary System
    ZHANG Jing-Chang, WU Xiang-Yang, CAO Wei-Liang
    2002, 23(1):  10-13. 
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    The Performance of supercritical fluid (SCF) as a solvent can be greatly affected by addition of an entrainer to the system. In this study, the constant volume visual method is used to measure the critical point properties of CO2+ toluene, CO2+ cyclohexane, CO2+ n-butyraldehyde, CO2+ i-butyraldehyde, CO2+ methanol and CO2+ ethanol binary systems. These properties provide a good basis for supercritical extraction and chemical reaction. The relationship between the critical point of CO2+ entrainer binary system and the critical point of supercritical carbon dioxide has been discussed. The phase behavior of single component system has been compared to that of CO2+ entrainer binary systems.
    Preparation And Gas Sensitivity of Octa-n -butoxy-2,3-naphthalocyanine Copper(Ⅱ) Langmuir-Blodgett Film
    HE Chun-Ying, HUO Li-Hua, WU Yi-Qun, ZUO Xia, XI Shi-Quan
    2002, 23(1):  14-17. 
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    The formation process of monolayer of octa n butoxy-2,3-naphthalocyanine copper(Ⅱ), [CuNc(OBu)8], on water subphase was studied. Its multilayers were successifully deposited on the hydrophilic substrates by Z-type deposition mode using LBtechnique. Stable solid film with a limiting molecular area of 0.74 nm2 and a collapse pressure of 55 mN/m were formed. The LB film structure was characterized by IRand electronic absorption spectra. Macrocycle of CuNc(OBu)8 molecules have a face to face arrangement in the multilayers. These films have good sensitivities to vapor of alcohols, with the following sequence of sensitivities: i-PrOH>EtOH>MeOH. The response time and recovery time of the LB films to vapor of MeOH, EtOH and i-PrOH[volume fraction (1-5)×10-5 ] were within 2 and 5 seconds respectively, while those of the LBfilms to ammonia(1×10-4) were 30-60 seconds and 4-5 minutes respectively.
    Chemistry of Borate(ⅩⅩⅩⅠ) Crystallization Kinetics of Mg-borates from MgO·2B2O3-18%MgSO4-H2O Supersaturated Solution
    MA Yu-Tao, XIA Shu-Ping, GAO Shi-Yang
    2002, 23(1):  18-21. 
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    The supersaturated solution of MgO·2B2O3-18% MgSO4-H2O was prepared and then kept in the thermostat of (0±0.1) ℃ and (20±0.1) ℃, respectively. The crystallization processes of Mg-bo-rates from the solution have been studied by the kinetic method. The crystallization kinetic equations were fitted from the experimental data. The solid phases were identified by IR-spectra, X-ray powder diffraction and TG-DSC thermal analysis.
    Crystal Structure of Tri(8-quinolinol) Nickel Coordination Compound [Ni2(HQ)3Q3] ClO4
    ZHANG Ming-Jie, HUANG Yan-Yi, HUANG Chun-Hui, XU Guang-Xian
    2002, 23(1):  22-23. 
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    A tri(8-quinolinol)nickel coordination compound, [Ni2(HQ)3Q3] ClO4, was synthesized and its crystal structure was determined by X-ray diffraction. The crystal structure indicated a space group of P21/c with a =1.6138(1) nm, b =1.5900(1) nm, c =1.9399(1) nm, β =94.663(2)°, V = 4.9612(6) nm3 and Z =4. Three strong hydrogen bonds were found in each unique unit between two tri(8-quinolinol) nickel fragments.
    Synthesis and Characterization of Mixed-valent Binuclear Manganese Complex [(Phen)2Mn(μ-O)2Mn(Phen)2](ClO4)3·CH2ClCOOH·2H2O
    LI Jun, ZHANG Feng-Xing, TANG Zong-Xun, SHI Qi-Zhen
    2002, 23(1):  24-26. 
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    Binuclear mixed-valent manganese complex [(Phen)2Mn(μ-O)2Mn(Phen)2] (ClO4)3·CH2ClCOOH·2H2Owas synthesized by the reaction of [Mn3O(O2CCH2Cl)6(C5H5N)2(H2O)] ·CH2ClCOO·H2O with Phen and NaClO4 in the CH2ClCOOH-CH2ClCOONa buffer (pH=4.0). X-ray diffraction result for the single crystal shows that the crystal is triclinic, space group P, with a =1.18264(7) nm, b =1.44932(8) nm, c =1.66499(9) nm, α =104.5850(10)°, β =97.1230(10)°, γ =106.9210(10)°, V =2.5816(3) nm3, Z =2, Dc=1.660 g·cm-3, R =0.0522. Apeak at 640 nm in UV-Vis spectrum is designed to the electronic transition of bridge legend O2- to Mn(Ⅲ). Cyclic voltammogram shows that the complex in CH3CN undergoes two quasi reversible one electron redox reactions at E1/2 =1.25 Vand E1/2=0.33 V, respectively.
    Studies on the Preparation, Structure and Properties of LB films of 12-Tungstomolybdophosphheteropolyacid with Dimethyldioctadecylammonium
    LIU Shi-Zhong, ZHANG Zhen-Wen, WANG Jun, DU Zu-Liang, DAI Shu-Xi
    2002, 23(1):  27-29. 
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    The LBfilms of two amphiphilic complexes, DODA/PW9Mo3O40 and DODA/PW6Mo6O40, were prepared from 12-tungstomolybdophosphheteropolyacid with dimethyldioctadecylammonium and their properties and the structure were characterized by UV-Vis absorption spectra, fluorescence spectra, low angle X-ray diffraction(LAXD) and π-A isotherms curves. The results showed that the molecular areas for each comlex are 0.56 nm2, and all of them could form an idealized structure with a stability of the Langmuir-Blodgetl films.
    Preparation and Evaluation of Open Tubular Electrochromatography Column with Derivated Polysiloxane as Stationary Phase
    LU Hao-Jie, OU Qing-Yu 
    2002, 23(1):  30-33. 
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    A simple and valid procedure for the preparation of open tubular electrochromatography column with derivated polysiloxane as stationary phase was established. When using polysiloxane derivated with butyl methacrylate and vinylsulfonic acid as stationary phase, the column has a strong ability for separation of the series of benzene. The separation efficiency of tuluene was 1.52×105 theoretical plates/meter and the retention factors of the series of benzene were larger than 2.40 After two months, there was no obvious difference in the separation ability of the column. In this method, the polymer was directly bonded in 50 μm i.d. fused silica capillary without pre etching. When using polysiloxane derivated with allyl-permethyl-β-cyclodextrin and vinylsulfonic acid as chiral stationary phase, naproxen could be enantiomeric separated with resolution of 0.81. In this method, the 50 μm i.d. fuse-silica capillary was primarily treated with Sol-Gel technology to increase the area of inner wall and the density of Si-OH.
    Application of p-Hydrazinebenzenesulfonic Acid to Carbohydrate Determination by CE Pre-capillary Derivatization
    WANG Xiao-Yan, CHEN Yi 
    2002, 23(1):  34-37. 
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    p-Hydrazinebenzenesulfonic acid was explored as a novel pre-capillary labeling reagent for CEof mono and disaccharides. The derivatization and the separation in borate buffer were investigated in detail. The derivatization took less than 10 min and the mass detection limit at 200 nm reaches 17.6 fmol of glucose, corresponding to concentration limit of 3.6 μmol/L. The baseline separation of 9 mono and disaccharides could be achieved within 11 min, using a running buffer composed of 100 mmol/Lborate at pH 10.24 This approach is also suitable for quantitation with linear coefficients higher than 0.992 at the concentrations between 0.1-9.1 mmol/L.
    Studies on AOTF as the Wavelength Selector for ETV-AAS
    TIAN Yuan, ZHAO Li-Wei, SUN Zheng, ZHANG Yi-Hua, SONG Da-Qian, ZHANG Han-Qi, JIN Qin-Han, JIN Dan-Hong
    2002, 23(1):  38-41. 
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    An experimental setup for atomic absorption spectrometry with a tantalum coil as the atomizer, and an acousto optic tunable filter(AOTF) as the wavelength selector was described. By using the atomic absorption spectrometry(AAS) Na was determined. The performance of AOTFwas evaluated. The effects of some operating conditions, including the electric current of HCL, the shielding gas flow rates, dry voltage, atomization voltage for tantalum coil atomizer on the absorption signal, were investigated. The characteristic concentration of Na was 0.045 μg/mLand the relative standard deviation was 2.6% (n =8) . Agood proportionality between absorbance and Na concentrion in the range of 0.050_1.0 μg/mLwas observed.
    Resonance Raman Spectroscopic Study of Cytochrome c Mutants
    ZHENG Jun-Wei, GU Ren-Ao, LU Tian-Hong
    2002, 23(1):  42-45. 
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    The spectroscopic characteristics of cytochrome c(WT) and its mutants(Y67F and N52I) in the low frequency region were studied by Resonance Raman technique. The results show that the replacement of phenylalanine for Tyr 67 in WThad a very slight effect on the hydrogen bonding and conformation of the amino acid residues around propionic acid side chains of heme group. However, large effects on the hydrogen bonding of internal water with its surrounding amino acid residues and hydrophobility of the heme cavity were observed as Asn52 was substituted with isoleucine, which resulted in conformational regulations of heme group and surrounding amino acid residues.
    The AFM Characterization of Ni(phen)3(2+)Fixing Effects on DNA
    YU Li-Hua, LI Zhuang, WU Ai-Guo, WANG Hong-Da, SUO Quan-Ling, BI Xiao-Hui, HUANG Bai-Qu
    2002, 23(1):  46-48. 
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    In this paper, the fixing and stretching effect of Ni(phen) 2+ 3 with different concentrations on DNAhad been studied by Tapping mode AFM. Under an ambient condition, the high resolution DNAimages were obtained, the average height, width and length of well spread DNAmolecules were measured. The results showed that because of the variations of ionic concentration, the density and topography of DNAmolecules on substrate had a great difference. The AFMand gel electrophoresis results also showed that, under our experimental condition, DNAmolecules kept intact, Ni(phen) 2+ 3 did not catalyze the cleavage activity of EcoRI, therefore, Ni(phen) 2+ 3 would be used to make high resolution physical mapping of DNAby AFM.
    Studies on the Synthesis, Relaxivity and Liver-targeting of DTPA-Pyridoxol Ester Gadolinium Complexes
    DING Xiong-Jun, ZHUO Ren-Xi, FU Gong-Cheng
    2002, 23(1):  49-52. 
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    Several new DTPA-pyridoxol ester ligands were synthesized by reacting diethylene-triam inepentaacetic anhydride(DTPAA) with pyridoxol derivatives. Their gadolinium complexes were also prepared. Their T1 relaxivities in water were measured. The 99Tc-labelled combination radioactivity experiment with liver cells and kidney cells of mice showed that ligands 2 and 6 possessed an excellent liver-targeting property. The results of animal MR imaging experiment further confirmed that the signals in liver were obviously strengthened after injection of Gd2 and Gd6.
    Synthesis of 3-Aryl-6-(6-/8-substituted-4-chloroquinoline-3-yl)-s- triazolo-1,3,4-thiadiazoles
    QIAO Ren-Zhong, HUI Xin-Ping, ZHANG Zi-Yi, CHENG Dong-Liang
    2002, 23(1):  53-57. 
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    Condensation of 4-amino-3-aryl-5-mercap to-1,2,4-triazole with 6-/8-substiuted-4-chloro|quinoline-3 carboxylic acid in the presence of phosphorus oxychloride gave 16 novel 3-aryl-6-(6-/8-substituted-4-chloroquinoline-3-yl)-s-triazolo-1,3,4-thiadiazoles(3a_3p). Their structures were determined by elementary analyses, IR, 1H NMR and MS spectra. Their spectral properties were also discussed.
    A Novel Method for the Syntheses of Stibazole Compounds
    WANG Zhi-Yong, ZHANG Zu-De, LI Qian-Rong, GUO Qing-Xiang
    2002, 23(1):  58-62. 
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    The application of Heck reaction to the preparation of stibazoles was investigated in detail. Also, the mechanism of the reaction in this situation was presented. Finally, a series of target compounds were synthesized by improved palladium-catalyzed reaction in excellent yields. Anovel, much efficient and convenient method for the preparation of stibazole compounds was afforded.
    Identification of Metabolites of Reinioside C, A Triterpene Saponin from the Roots of Polygala fallax Hemsl
    ZHANG Dong-Ming, Miyase Toshio, Noguchi Hiroshi, Tanizawa Hisayuki, MA Wan-Yun, CHEN Die-Yan
    2002, 23(1):  63-67. 
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    Triterpene saponins were widely distributed in the oriental traditional crude drugs, which play important roles as anti-inflammatory, anticancer and antihepatitis agent. For example, from Ginseng Radix, Bupleuri Radix, Polygalae Radix, Platycodi Radix etc, many bioactive and available triterpene saponins were obtained and they could explain the effect of the crude drug. However metabolic transformation of triterpene saponin in vivo have not been reported. We studied the metabolism of reinioside C, a triterpene saponin from the roots of Polygala fallax Hemsl in rats. After oral administration of reinioside C, seven metabolites(RA-RG) of reinioside Cwere obtained from the content of large intestin and feces. The structures of metabolites were elucidated as 28-O-α Lrhamnopyranosyl-(1→2)-(3,4 diacetyl)-β-Dfucopyranosyl presenegin, 28-O-β-Dxylopyranosyl-(1→4)-α-Lrhamnopyranosyl-(1→2)-(3,4 diacetyl)-β-Dfucopyranosyl presenegin, 28-O-α-Lrhamnopyranosyl-(1→2) (3,4-diacetyl)-β-Dfucopyranosyl presenegin3 O-β-Dglucopyranosyl-(1→2)-β-Dglucopy ranoside, 28-O-β-Dxylopyranosyl-(1→4)-α-Lrhamnopyranosyl-(1→2)-β-D-fucopyranosyl presenegin 3-O-β-Dglucopyranosyl-(1→2)-β-Dglucopyranoside, 28-O-β-Dxylopyranosyl-(1→4)-α-Lrhamnopy ranosyl-(1→2)-(3 acetyl)-β-D-fucopyranosyl presenegin-3-O-β-D-glu copyranosyl-(1→2)-β-D-glucopyranoside, 28-O-β-D-xylopyranosyl-(1→4)-α-Lrhamnopyranosyl-(1→2)-(4 acetyl)-β-D-fucopyranosyl pre senegin3 O-β-D-glucopyranosyl-(1→2)-β-Dglucopyranoside, 28-O-β-D-fucopyranosyl presenegin, respectively, on the basis of spectroscopic data.
    Synthesis of α-Amino Alcohols via Rh(I)-catalytic Asymmetric Hydrosilylation of Amino Ketones
    YAO Jin-Shui, WU You-Shi
    2002, 23(1):  68-70. 
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    The asymmetric hydrosilylation of 2-amino aryl ketones catalyzed by [Rh(COD)Cl]2/2-(2-pyridyl)-4-carbomethoxy-1,3-thiazolidine(A) systems was first reported. The chiral 2-amino-1-aryl ethanols were obtained in nearly quantatative yield and high enantioselectivity. The reaction of fourteen 2-amino arylketones with different groups were investigated. It was found that the %e.e.% values were all higher than 92% when there are group(s), such as OH, OM e or Me on the phenyl group,while the optical purities were less than 85% e.e. when there are group(s) such as Cl, NO2 on the phenyl group. In comparision with the reaction of ketones having no founctional group, the optical yield of 2-amino ketones were higher.
    A Mathematical Model for Biosynthesis of Medium-chain-length Polyhydroxyalkanoates by Pseudomonas stutzeri1317
    XU Jun, HE Wen-Nan, GUO Bao-Hua, HU Ping, ZHANG Zeng-Min, ZHANG Guang, LIN Hui-Lan, CHEN Jin-Chun, CHEN Guo-Qiang
    2002, 23(1):  71-74. 
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    When grown on various carbon sources, P. stutzeri 1317 strain accumulates medium-chain-length polyhydroxyalkanoates(mcl PHAs) of various monomer composition. Amathematical model was developed to investigate what affects mcl PHAcomposition and how to tailor design the copolymer, and some interesting conclusions were deduced: the monomer composition was independent of cultivation time and the enzyme level; the content variance of different monomers resulted only from the selectivity ratio of the polymerase to the enzymes involved in theprecursor formation pathway; modulation of precursor formation pathway led to convenient manipulation of PHA monomer composition. The experimental results from several Pseudomonas strains proved the model an effective tool for tailor-design of mcl PHA copolymers.
    Investigations on the Adsorbents for Uremic Middle Molecular Toxins(Ⅰ) Glutaraldehyde-crosslinked Chitosan Adsorbent
    WANG Hong, YUAN Zhi, TENG Xin-Lian, HE Bing-Lin
    2002, 23(1):  75-77. 
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    Glutaraldehyde-crosslinked chitosan used in the adsorption upon model uremic middle molecular toxins was studied. In comparison with untreated glutaraldehyde crosslinked chitosan resin beads, the hydrogen reduced ones showed a quite realistic behavior in the adsorption upon those model toxins, and the amount of adsorption was fairly high while the equilibrium time was obviously shortened.
    Studies on Preparation and Crystal Structure of Ultrafine Particles Zn-Mg-Al-Hydrotalcite-like Compound
    JIANG Peng, HOU Wan-Guo, HAN Shu-Hua, HU Ji-Fan, LI Dong-Qing
    2002, 23(1):  78-82. 
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    The particles of zinc magnesium aluminum hydrotalcite like compound(Zn-Mg-Al-HTlc) were synthesized by nonsteady coprecipitation method. Their chemical composition, crystal structure, particle morphology and the influence of material ratio were studied. The results show that the molar ratio of (Zn+Mg) to (Zn+Mg+Al) in preparing Zn Mg Al HTlc samples is lower than that of the material, and so is the molar ratio of Zn to (Zn+Mg+Al). However, the molar ratio of Mg to (Zn+Mg+Al) has no changes basically. Pure HTlc phase forms when molar ratio of Al to (Zn+Mg+Al)(x) is between 0.22 and 0.40, and different phases will form beyond this range. When x is lower than 0.22 or higer than 0.40, ZnOor Al(OH)3 will emerge respectively. The lattice parameters of Zn-Mg-Al-HTlc particles, a = 0.27 -0.32 nm; c =2.27-2.42 nm; basal spacing is in the range of 0.75-0.81 nm. The height of gallery is about 0.30 nm. It was found that the particles of prepared samples are comparatively complete hexagonal plate particles. The particle size is determined respectively by TEM, particle size instrument and XRD-Scherrer formula. It is proved by XRD-scherrer formula that the particle′s mean crystal grain is between 30- 45 nm . The TEM results show that the mean particle size decreases with the decreasing of x . That is, when the content of divalent metal cations increases, the mean particle size decreases. When x is lower than 0.33, the mean particle size is basically lower than 100 nm. Remaining constant x, the mean particle size has an increasing tendency with the increasing of Zn content; with the increasing of Mg content, the mean particle size has a decreasing tendency.
    Adsorption and Reaction of CO on the Sm/Rh(100) Model Surface
    MA Yun-Sheng, ZHU Jun-Fa, ZHOU Wei-Ping, ZHAI Run-Sheng, BAO Xin-He, ZHANG Xin-Yi, ZHUANG Shu-Xian
    2002, 23(1):  83-86. 
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    The preparation of Sm overlayer and Sm/Rh surface alloy on Rh(100) surface, adsorption and reaction of CO on these two model surfaces were investigated with AES, LEED, XPS and TDS. The growth of Sm overlayer appears following the SKmode at room temperature. Annealing of Sm overlayer at 900 Kleads to formation of the ordered Sm/Rh surface alloy which exhibits the c(5√2×√2)R45°-Sm and c(2×2)-Sm LEEDpatterns. The morphology of Sm/Rh(100) surface changes completely during COadsorption due to the formation of SmOx and surface carbon. With the increasing of the Sm coverage, a drastic decrease in the peak area and a peak shift to higher temperature were observed for the low temperature desorption of CO(α-CO) from the Sm/Rh(100) surface, indicating that both the site blocking of pre adsorbed Sm and the electron donation from Sm can simultaneously affect the COadsorption. In the case of the Sm/Rh surface alloy, a new desorption peak of COgrows at ~590 K, which is assigned to COon the Sm-affected Rh sites.
    Preparation Chemistry of Fe1-xO Based Catalyst for Ammonia Synthesis
    LIU Hua-Zhang, Li-Xiao-Nian, HU Zhang-Neng, CEN Ya-Qing, FU Guan-Ping
    2002, 23(1):  87-91. 
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    The preparation chemistry of iron catalyst for ammonia synthesis is studied by molten method and X-ray diffraction. The chemical reaction and the change of crystal phase of iron oxide during the molten procedure is investigated according to Fe-O equilibrium diagram. The effect of solidifying-cooling rate of molten materials on the distribution of the promoters is exposed. It is indicated that Fe 2O3 and stoichiometric ferrous oxide FeO is not able to be obtained by molten method at atmosphere; Fe3O4 or non stoichiometric magnetite Fe3-yO4 of n (O)/ n (Fe) in the range of 1.333-1.38 and the mixture oxide of Fe3O4 and FeOof n (O)/ n (Fe) in the range of 1.111-1.333 may be obtained by the same method ; but non-stoichiometric ferrous oxide expressed as Fe1- x O or Wustite of n (O)/ n (Fe) in the range of 1.045- 1.111 may be obtained only when the cooling rate of molten materials is more than 20 ℃/min by molten method at atmosphere. There are observable influences of the solidifying cooling rate on the inhibition of the oxidation reaction and the disproportionation of the ferrous oxide Fe1- xO and improvement of the distribution of the promoters.
    CO2 Reforming of CH4 over Ni Supported on Nano-ZrO2(Ⅰ) Comparison with Conventional Oxide Supported Nickel
    WEI Jun-Mei, XU Bo-Qing, LI Jin-Lu, CHENG Zhen-Xing, WANG Ya-Quan, ZHU Qi-Ming
    2002, 23(1):  92-97. 
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    The catalytic activity and stability of Ni supported on γ-Al2O3, TiO2, SiO2, conventional ZrO2-CP, and nano-ZrO2-AS(15-20 nm) were comparatively studied for CO2 reforming of CH4 to synthesis gas. The Ni loading in these catalysts was limited to 5%(mass fraction) of the supports, and the reaction was performed in a fixed bed flow microreactor at 1030 K with GHSV=2.4×104 mL/(h·g cat). The initial CH4 conversions of the catalysts are in the order of Ni/ γ-Al2O3>Ni/TiO2>Ni/ZrO2-CP> Ni/ZrO2-AS > Ni/SiO2 . Ni catalysts supported on γ-Al2O3, TiO2, ZrO2-CP and SiO2 deactivated rapidly in less than 50h TOS, but Ni/ZrO2-AS catalyst showed no deactivation for longer than 200h. The pure ZrO2-AS also showed a catalytic activity for the reaction and no loss of the activity was observed during50 h on stream at 1073 K. TPOmeasurements demonstrated that carbon deposition on the Ni/ZrO2-AS catalyst was much less and was eliminated at lower temperature than those over the other catalysts. Explanation for the excellent stability of Ni/ZrO2-AS catalyst was given based on the present data. It is suggested that Ni/ZrO2-AS can be better expressed as a nano composite of the Ni and ZrO2-AS, and high percentage of the metal-support perimeter in the composite seems crucial for the long stability of the catalyst.
    Production of Carbon Nanotubes With Different Shapes By Catalytic Pyrolysis of Methane
    WU Guo-Tao, ZHU Guang-Ming, YOU Jin-Kua, LIN Zu-Geng
    2002, 23(1):  98-101. 
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    In the present work, different-shaped carbon nanotubes produced by catalytic pyrolysis of methane over Ni-catalysts at low temperature (500-700 ℃) were observed by TEM. It was found that the outer and inner diameters of carbon nanotubes and the size and morphology of Ni- catalysts are mainly determined, which was strongly affected by the kind of catalyst precursors and the reaction temperature. The length of carbon nanotubes became short when the reaction temperature was decreased or the flow rate of methane was improved.
    Solid State Synthesis and Study of Raman Spectrum of α-LiAlO2
    GONG Jie, LIU Wei, LI Ji-Xue, WANG Chun-Zhong, ZONG Zhan-Guo, CHEN Gang
    2002, 23(1):  102-104. 
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    We have for the first time measured Raman spectrum from a solid state synthesized LiAlO2. There are two Raman bands located at 654 cm-1 and 426 cm-1, which corresponds to A1g and Eg models, respectively. The interaction between the layers along c axis in α-LiAlO2 is weaker than that in α-LiCoO2. The characteristics of a layer compounds in α-LiAlO2 is stronger.
    The Theory Study of Molecule Design, Electronic Spectrum and Nonlinear Optical Property about Benzenespiro-conjugated Molecules Inserted by 1,3-Squaric Acid
    SUN Shi-Ling, SU Zhong-Min, KAN Yu-He, CHEN Li-Hua, ZHU Yu-Lian, REN Ai-Min, FENG Ji-Kang
    2002, 23(1):  105-108. 
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    On the basis of geometry optimized by quantum chemical PM3 method, electronic spectrum of 1,3 squaric acid tumbled in benzene spiro conjugated molecules was discussed by INDO/CImethod. The second order optical susceptibilities βijk and βμ of benzene spiro-conjugated molecules tumbled with 1,3-squaric acid were calculated by INDO/CI-SOS program. Theoretical calculation shouled that 1,3-squaric acid was tumbled in benzene spiro-conjugated molecules properly that made its second order optical susceptibilities increase. Compared with benzene spiro-conjugated molecule and 1,3-squaric acid, squaric acid that was tumbled in left bears better nonlinear optical property and possibly becomes a nice optical material.
    Theoretical Studies on Asymmetric Boron-catalyzed Reaction(Ⅰ) The Enantioselectivity in Oxazaborolidine-catalyzed Reductions of Phenyl Ethyl Ketone
    SUN Cheng-Ke, YANG Si-Ya, MA Si-Yu, LI Zong-He
    2002, 23(1):  109-112. 
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    The reaction mechanism of the enantioselectivity in oxazaborolidine catalyzed reductions of phenyl ethyl ketone has been studied by using AM1 method and transition state theory. The results show that the boron-catalyzed reactions consist of two similar parallel reactions in which the reactants(R) of the title compound and boron catalyst generate the enantiomers(PR and PS) via intermediate compounds IC(R) and IC(S) and transition states TSR and TSS, respectively. The enantioselectivity is determined by the ratio of the rate constants of two reactions. The value is 40 (that is R:S =97.5:2.5 or e.e. (R) =95%), which is in good consistence with experiment [exp. e.e. (R) =97(95)%]. The determining factors of the rate ratio come from the joint contribution of the activation enthalpy and activation entropy.
    Theoretical Study on the Tautomerism of 1-3H Atom Transformation Reactions at the 3N System Substituted by Halogen
    YE Song 
    2002, 23(1):  113-115. 
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    Ab initio method has been used to study the reaction of 1-3H atom transformation reactions at the 3N system substituted by halogen. The calculation results have shown that the active energy of tautomerism and stability of N=N affectted by the substituted halogen.
    The Growth Mechanism of the Anodic Pb(Ⅱ) Film Formed on Lead-tin Alloy in Sulfuric Acid Solution
    LIU Hou-Tian, LIANG Hai-He, YANG Jiong, ZHOU Wei-Fang
    2002, 23(1):  116-120. 
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    The properties of the anodic oxide film formed on Pb and Pb Sn alloy in 4.5 mol/L H2SO4 solution at 0.9 V(vs . Hg/Hg2SO4) have been investigated by the a.c. technique, open circuit decay curve, and linear sweep voltammetry. It was found that the anodic film grows via a dissolution-precipitation process. The PbO particles in the anodic film may be anodized further by using the interstitial liquid among the PbO particles for ionic transportation. Tin facilitates the process of oxidation of the surface layer of the PbO particles to PbO 1+x (0<x <1).
    The Role of Bond Functions for Calculating the ArCl- Potential
    SUN Yan-Bo, WU Di, LI Zhi-Ru, SUN Chia-Chung
    2002, 23(1):  121-122. 
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    The coupled cluster theory is applied to calculate the anion-neutral potential of ArCl-. Ascheme for constructing a very efficient basis set is proposed based on theoretical consideration. The basis set is Aug-cc-pVQZ (moved g functions) containing {3s3p2d1f} bond functions. Detail CCSD(T) calculations on ArCl- give a global potential minimum with a well depth -61.17 meVat the position R =0.371 nm. This is in good agreement with experiment, especially with the piecewise Morse-Switching function-van der Waals (MSV) potential to fit the zero electron kinetic energy spectroscopy of the ArCl- anion. The spectroscopy is observed by Lawrence Berkeley National Laboratory.
    The Raman Detection of Single Molecule at the Aggregated Silver Particle Films on Air-water Interface
    HU Jia-Wen, ZHAO Bing, XU Wei-Qing, XIE Yu-Tao, FAN Yu-Guo, LI Bo-Fu, WANG Hua
    2002, 23(1):  123-125. 
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    We have found that the silver colloids, which usually used as SERSactive substrate, are inclined to aggregation on air-water interface and forming a two-dimension silver particle films. The formed silver particle films exhibit much higher surface Raman enhancement factor than silver colloids, and the power used on silver particle films is only about 1% of that on silver colloids. Combining with resonance Raman enhancement technique, we realize single molecular Raman detection under the common conditions by using this silver particle films as SERSactive substrate.
    Rare Earth Elements-Doped Spinel LiM0.02 Mn1.98O4 as the Cathodic Materials for Lithium Ion Batteries
    WAN Chuan-Yun, NULI Yan-Na, JIANG Zhi-Yu
    2002, 23(1):  126-128. 
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    Spinel lithium manganese oxides doped with rare earth elements in forms of LiM0.02 Mn1.98O4 (M=La, Pr and Sm) were prepared and their electrochemical properties for lithium ion intercalation reaction were investigated. The materials were prepared by solid state reaction using electrolytic MnO2, Li2CO3 with Pr2O3, Sm2O3 or La(NO3)3·H2O. From the voltammetry test it was found that the reversibility of lithium intercalation reaction could be improved by doping with Sm or Pr into spinel lithium manganese oxides. Although the first discharge capacity was decreased by about 10% for LiPr0.02Mn1.98 O4 and LiSm0.02Mn1.98 O4 compounds compared with undoped LiMn2O4, but their cycling properties were improved, obviously.
    Charaterization of the Phase and Valency State of Co on Co/HZSM-5 Catalysts
    ZHANG Qiang, WANG Xiao-Dong
    2002, 23(1):  129-131. 
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    The phase and valency state of cobalt species on Co/HZSM-5 catalysts containing 10% to 100% cobalt were characterized by XRD, TPR and DRStechnique. It was found that cobalt species on Co/HZSM-5 may exist in the phases of Co3O4, CoO, CoAl2O4 spinel, exchanged Co or metal Co at different calcination and reduction temperature, and CoAl2O4 spinel is difficult to be reduced.
    Studies on Electronic Structures and Spectra of C75N+
    WU Shi, TENG Qi-Wen 
    2002, 23(1):  132-134. 
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    The 19 isomers of azafullerenes C75N+ were studied with series of INDOmethods. It was shown that the isomer in which the carbon atom near C2(x) is substituted by the nitrogen atom is the most stable one. The nitrogen atom has negative charge and may become a further center for reaction. The bands of the UVspectra of C75N+ will be red shifted to 700-850 nm compared with those of C76 . The nature of transition was assigned and the reason of red shift was also rationalized.
    Studies on Complexes of Lanthanum with Amino Acids by Temperature Titration Calorimeter Method
    YE Gang, WANG Cun-Xin, WANG Zhi-Yong, LIU Yu-Weng, QU Song-Sheng
    2002, 23(1):  135-137. 
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    The stability constants and thermodynamic functions for complexes of lanthanum with some amino acids have been determined by temperarature titration calorimeter at 298.15 K. The enthalpy change makes a predominant contribution to the stability of these complexes. The ring in amino acid associated with lanthanum iron helps to enhance the stability of complexes
    Synthesis of Amphiphilic Block Copolymer Poly(styrene-b-acrylic acid) by Atom Transfer Radical Polymerization and Its Micellization
    ZHU Hui, LIU Shi-Yong, PAN Quan-Ming, DUAN Hong-Wei, JIANG Ming 
    2002, 23(1):  138-142. 
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    Amphiphilic block copolymers of PS-b-PAA with a low polydispersity have been synthesized by atom transfer radical polymerization (ATRP) and characterized by FTIR, 1H NMR and SEC. The micellization of PS-b-PAA in water have been monitored by fluorescent probe technique. It was found that pyrene as a fused-ring aromatic hydrocarbon(PAH) can be absorbed and further separated and recovered from water by using the PSb PAAmicelles. The results showed that the equilibrium loading of pyrene apparently depends on the length of the hydrophilic block and the concentration of the micelles. This work, therefore, displays a potential use of the micelles in the purification of waste water contaminated by aromatic compounds.
    Synthesis of A Novel Zirconocene Complex (1,2-Ph2-4-PrCp)2ZrCl2 and Catalysis for Olefin Polymerization
    ZHANG Fan, MU Ying, CHEN Cong-Xi 
    2002, 23(1):  143-146. 
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    A new cyclopentadiene derivative 1,2-diphenyl-4-propyl-1,3-cyclopentadiene(1) was synthesized by reaction of 3,4-diphenyl-2-cyclopentenone with n propyl lithium. 1 was treated with n butyl lithium and then reacted with ZrCl4 in toluene to give sterically bulky unbridged zirconocene dichloride(1,2-Ph2-4-PrCp)2ZrCl2(2). 1H NMR and 13 C NMR spectroscopic analyses reveal its C2v-symmetric conformation in solution. Upon activation with methylaluminoxane(MAO), 2 effectively polymerizes ethylene and produces high molecular weight polyethylenes with high melting transition temperatures at low Al/Zr ratios. At ambient conditions, 2/MAO system shows high catalytic activity in propylene polymerization and produces oily oligomers.
    Synthesis, Characterization and Ring-opening Polymerization of Poly(trimethylene terephthalate) Cyclic Oligomers
    WAN Xin-Hua, CAO Yu, ZHANG Fei, SUN Ling, ZHOU Qi-Feng
    2002, 23(1):  147-151. 
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    Cyclic oligomers of poly(trimethylene terephthalate)(PTT) were prepared by reaction of 1,3-propanediol with terephthaloyl chloride(TPC) under diluted conditions and separated from the linear products by silica gel column. The structures of PTToligomeric cyclics were confirmed by means of 1H NMR, mass spectrometry, and elementary analysis. Cyclic dimer, trimer, tetramer, pentamer and heptamer were further separated by gel permeation chromatography and high performance liquid chromatography. They were found to constitute most of the cyclics mixtures with a preponderance of the cyclic trimer. The cyclic oligomers melt at 92.3~222.6 ℃, providing liquids of low viscosity. Ring opening polymerization was carried out by heating the sample mixtures at 250 ℃ for 15 minutes in the presence of conventionally used catalysts, such as Sn(Oct) 2, 1-ethoxy-3-chlorotetrabutyldistannoxane, Ti(OBu)4 and antimony oxide. The inherent viscosity of PTT prepared via ring opening polymerization was as high as 0.49 dL/g.
    Oriented Crystallization Process of Polypropylene Fractions
    SHI Hong-Wei, YANG De-Cai 
    2002, 23(1):  152-154. 
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    Melting recrystallization processes of melt sheared films of polypropylene(S28C) fractions have been investigated in situ by polarized optical microscope equipped with CCDcamera and hot stage. Actually, the morphological developments in the melting recrystallization are partially reappearance of oriented crystallization processes during melt shearing the fractions, which is due to a memory effect of oriented structure of polymer. For low molecular weight fraction, only incomplete spherulites with some orientation along shear direction are observed in the melting recrystallization processes of the sheared films. For middle molecular weight fractions, extended chain fiber crystals(or bands) are formed first at higher temperatures, and the bands can act as self nuclei(i.e ., row nuclei), resulting in epitaxial growth of chain folded lamellae(or fibril), i.e ., the formation of cylindrites, with further decrease of the crystallization temperature. For high molecular weight fraction, however, it is not possible to shear the melt film because of its high melt viscosity. When the low molecular weight fraction in which no fiber crystals or cylindrites are observed, are mixed with small amount(about 1%—2%) of the high molecular weight fraction, quite large number of cylindrites are formed during the melting recrystallization process of its sheared film, which implies that the component of high molecular weight plays an important role in the formation of cylindrites during the shear process of polypropylene.
    Studies on the Self-assembly of Aliphatic-aromatic Hyperbranched Polyester with Carboxylic End-groups
    QIU Teng, TANG Li-Ming, TUO Xin-Lin, ZHANG Xiao-Long, WANG Xiao-Gong, LIU De-Shan
    2002, 23(1):  155-157. 
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    Carboxylic ended aliphatic aromatic hyperbranched poly(5-hydroxyethoxyisophthalic acid)(PHEIA) was employed for an electrostatic layer-by-layer self assembly procedure. The self-assembly films have been successfully formed from both aqueous solution and water THF mixture. The self assembly procedure was monitored by UV-Vis spectroscopy and contact angle measurement meter. The obtained multilayers were characterized by AFMfor the surface morphology investigation. The results indicate that PHEIAis able to form self assembly film in the presence of poly(diallyldimethylammonium chloride) (PDAC). On the self assembled surface where PHEIAacted as an outmost layer, the PHEIAaggregated into sphere-like particles with uniform diameter. Furthermore, the layer-by-layer self-assembly procedure provided a favorable method for modification of the hydrophilicity of the substrate without heavy interpenetration between these two polyelectrolyte layers.
    The Preparation of Hollow Nano-fiber from Tri-block Copolymer
    ZHOU Ru-Ling, ZHOU Nan, YAN Xiao-Hu, LIU Guo-Jun
    2002, 23(1):  158-160. 
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    The solid state morphology of the tri-block copolymer PS-b-PCEMA-b-PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After being blended with polystyrene with the mass ratio of 1:04, the morphology showed cylinder structure. With PSas continous phase, PCEMA and PtBA phases formed cylinders with PCEMA as outer layer. The nanofibres can be got and dispersed in good solvents of PS when the PCEMA phase was crosslinked. The t-butyl group in PtBA phase can be cleavaged by reacting with TM-SI, and nanofibres changed to nanotubes finally. It has the great potential applications, such as in the preparation of nanowires, template polymerization, nano reactor etc ..
    Effect of TiO2 Nanoparticles on the Properties of PANI
    LIU Shao-Qiong, YU Huang-Zhong, HUANG He, XIONG Yu-Ying
    2002, 23(1):  161-163. 
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    Polyaniline/TiO2 nanocomposites was prepared in the presence of titanium dioxide. The incorporation of polymers in the composites was proved by FTIRstudies. The nanocomposites have been characterized by four point probe conductivity measurements, UV-Vis, transmission electron micrograph. The results show that polyaniline/TiO2 has a higher conductivity(×10-2) compared with that of EB, the UV-Vis spectra properties of polyaniline/TiO2 depend on the ratio of TiO2 to polyaniline. The UV-Vis spectrum of the nanocomposites doped with HCSAshows a red shift and possesses a higher conductivity and better solubility compared with those of nanocomposites and PANI. TEMmicrographies show that TiO2 nanoparticles are partly coated with the polymer.
    Kinetics of Reactions Between Dibasic Acid Half- ester With Epoxy Compound
    ZENG Zhao-Hua, YANG Jian-Wen, QIN Hai-Ding, CHEN Yong-Lie
    2002, 23(1):  164-166. 
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    The kinetic behavior of reaction of dibasic acid half-ester with epoxy compound, which is one of the key reaction occurring in the technology of liquid alkali developing type solder resists, was investigated in this paper, by using the monomethyl esters of maleic acid, succinic acid, phthalic acid, cis-1,2,3,6-tetrahydrophthalic acid and cis-hexahydrophthalic acid as model compounds. It was found that for the reaction catalyzed by tetramethyl ammonium bromide(TMAB), the reaction order for dibasic acid half ester and for PGE is 0.5 and 1 respectively when the dibasic acid monomethyl-esters with a smaller size and/or with a stronger acitity were used, while it is 0 and 1 respectively when the dibasic acid monomethyl-esters with a larger size and a weeker acitity were used. The reaction mechanism has also been discussed, from which a rate equation has been obtained which is in agreement with the experiment results.
    Synthesis and Characterization of High Molecular Weight Atactic Polybutene-1 and Butene-1 Polymerization Catalyzed by Titanocene/MAO Catalyst
    HUANG Qi-Gu, LIN Shang-An, ZHU Fang-Ming, WU Qing
    2002, 23(1):  167-169. 
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    5-Pentamethylcyclopentadienyl) titanium triallyioxide[Cp*Ti(OCH2-CH=CH2)3 was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio of n (Al) to n (Ti), polymerization temperature, and concentration of Ti on catalytic activity, molecular weight and chain structure were investigated in detail. The ether soluble fraction of the polybutene-1 was characterized with 13 C NMR, DSC, WAXD, and GPC. The results indicate that the polymers thus obtained are atactic and regioirregular, the weight average molecular weight of these polymers lies in the range of 3.0×105 to 7.0×105. Increasing the polymerization temperature can result in a decrease in the polymer molecular weight. But the molecular weight varies slightly with the ratio of n (Al) to n (Ti). The catalytic activity tends to decrease with the increase in polymerization temperature. was used as the catalyst precursor for the synthesis of polybutene 1, methylalumiunoxane(MAO) as cocatalyst. The effects of the ratio of n (Al) to n (Ti), polymerization temperature.The catalytic act ivity tends to decrease w ith t he increase in polym erizat ion tempera-ture.
    Photosensitive Ultra-thin Films of Chitosan and Sulfonate of Diazoresin
    LU Cong-Hua, CAO Ting-Bing, LUO Chuan-Qiu, CAO Wei-Xiao 
    2002, 23(1):  170-172. 
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    On the substrate of modified quartz, two kinds of self assembled ultra-thin films were fabricated through layer-by-layer electrostatic deposition with diazoresin′s sulfonate(DRS) as the polyanion, and chitosan(CS) as the polycation. The self assembly process was monitored by UV-Vis spectra and confirmed that the layer-by-layer deposition takes place regularly. The films obtained both from DRS, CS(CS/DRSfilm) and from DR, DRS, CS(DR/DRS/CS/DRSfilm) were photo sensitive. Under irradiation of ultraviolet light, the stability of the films towards polar solvents increases significantly. The kinetic study shows that the rate of the photodecomposition reaction of DR/DRS/CS/DRSfilms is higher than that of CS/DRSfilms and doesn't show the first order reaction for both films.