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    24 April 1993, Volume 14 Issue 4
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    Articles
    Studies on the Rapid Synthesis, Structure and Properties for TiZSM-48
    ZHANG Chun-Lei, WU Zhi-Yun, SHA Xiu-Hong, XU Yi-Hua, ZHAO Zhong-Qing
    1993, 14(4):  445-449. 
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    The TiZSM-48 zeolite was synthesized under a dynamic condition by using1,6-hexamethy-lene-diamine as the template.The crystallizing rate of the dynamic state method was compared with that of the statical state method.The results show that the crystallizing rate of the former is much faster than that of the latter.The structure and properties of TiZSM-48 were investigated by IR, XRD, EPMA, XPS, DRS, ect..The results confirm that Ti4+ occupies Tsite of the framework of the zeolite and are well distributed.
    Studies on the Preparation of Potassium Peroxytungstates from WPTA-H2O2-KOH System
    SHI Xiao-Bo, YUE Bin, LIN Bing-Fa, JIN Song-Lin, ZHU Si-San, XIE Gao-Yang
    1993, 14(4):  450-453. 
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    Three potassium peroxytungstatesK2W(O2)4(PPT-1), K2W2O3(O2)4·4H2O(PPT-2) and K2W2O5(O2)2·4H2O(PPT-3) were prepared by the disaggregation of white powdery tungstic acid with 4%-15% H2O2 at room temperature and adjusting pHvalues with potassium hydroxide soluti-ion.PPT-3 is a new compound, its structure has been induced.The peroxytungstates were characterized by IRspectra, UVabsorption spectra, X-ray powdery diffraction and thermogram.It is verified that there exists a new phase of K2W2O7.
    Separation and Purification of Rat Liver Metallothionein, Preparation of α-Domain Fragments of MT-Ⅱ and Their Characterization by NMR
    HUANG Zhong-Xian, GU Wei-Qiang, HU Hong-Yu, WANG Yun-Hua
    1993, 14(4):  454-457. 
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    The rat liver metallothionein was induced by administering 7 subcutaneous injection of CdCl2 to the wistar rat.The purification protocal involved homogenization of rat liver, heating, extraction by ethanol-chloroform, acetone precipitation, and finally, chromatography on Sephadex G-75 and DEAE-52 columns.Two isoforms of metallothionein, Cd5Zn2-MT-Ⅰ and-Ⅱ, with A250/ A250> 20 were obtained.MT-Ⅱα domain fragment containing four cadmium ions was also isolated by digestion with subtilysin.1H NMRspectra of MT-Ⅰ,-Ⅱ were in agreement with those reported in literatures.The spectrum of MT-Ⅰ α domain shows that there is no existence of β fragment in this preparation.
    Synthesis and Characterization of Potassium α-and βTrivanadononatungstogermanate
    CHEN Ya-Guang, QU Lun-Yu, PENG Jun, YU Ming
    1993, 14(4):  458-461. 
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    Potassium α-and β-trivanadononatungstogermanates were prepared and characterized by elementary analysis, IR, UV, 51Vand 183W NMRspectra, polarography, TG-DTAthermal analysis, and single crystal X-ray diffraction analysis.The results show that these new compounds have Keggin anion structures, in which three Vatoms belong to three different M3O13 units and link to each other by sharing a oxygen atom.The α-isomer is A-type structure and has a little stronger oxidation ability than the β-isomer.In comparison with GeW12, the thermal stabilities of substituted heteropoly compounds GeW9V3decrease and their oxidation abilities increase greatly.
    Synthesis and Characterization of New Type GaPO4 Molecular Sieves
    LIU Zhen-Yi, LI You-Shi
    1993, 14(4):  462-465. 
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    Two kinds of new type gallopbosphate molecular sieves were synthesized by using dipropy-lamine (DPA) and diethylamine (DEA) as the templates.One is named GaPO4-C, and the other GaPO4-O.GaPO4-C belongs to the cubic system with the parameter of unit cell α=1.1948(2) nm.GaPO4-Obelongs to orthorhombic system with the parameters of unit cell α=2.1192(4) nm, b=0.9738(5) nm, c=0.9225(5) nm.By using IRanalysis, it was found that there is Ga-OHbond in GaPO4-Oframework and not any in GaPO4-C.After 450℃ calcinating, the framework of GaPO4-Cis partly collapsed and the framework of GaPO4-Ois wholly collapsed.The adsorption experiment of the samples after calcinating indicates that the secondary pore formed in the framework of the samples.The pore size of the secondary pore-fermed by GaPO4-Cis between 0.43-0.60 nm.The pore size of the secondary pore formed by GaPO4-Ois bigger than 0.6 nm.
    Polymerizational Kinetics of Metallothionein
    ZHANG Bao-Lin, REN Hong-Wei, WANG Wen-Qing
    1993, 14(4):  466-467. 
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    Chromatographic separation of the aqueous solutions of rabbit hepatic (Cd,Zn)7MTin50 mmol/Lsodium phosphate (pH 7.40) after storing for various time was performed on HPLCin an attempt to investigate the thermodynamic stability of the Metallothionein (MT) solution.It was found that MTcould polymerize slowly by itself.Assuming the polymerization only occurs from monomer to dimer, an apparent bimolecular rate constant of the order of 10-3(mol/L)-1·/day-1 at 4℃ was obtained.The results also clearly reveal that the isoform MT-2 can polymerize more easily than MT-1.
    Indirect Electrochemical Detection with Liquid Chromatography for Non-electroactive Esters
    JIN Li-Tong, YE Jian-Nong, SONG Wei, FANG Yu-Zhi
    1993, 14(4):  468-471. 
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    The method of indirect electrochemical detection accompanied with liquid chromatography (Indirect LCEC) was applied to separate and determine the non-electroactive esters containing methyl formate, ethyl formate, methyl acetate and ethyl acetate.It was shown that the peak current was linear in the range of 3.2×10-9-4.4×10-8mol, 2.4× 10-9-2.8×10-8 mol, 2.0×10-9-4.0×10-8 mol and 2.2×10-9-2.4×10-8 mol for these four compounds, respectively.The relative standard deviation of eight parallel determination is 0.89 %.The method was applied to determine the concentration of methyl formate in waste water, the recovery was in the range of 97% to 108%.The mechanism of indirect electrochemical detection of non-electroactive species is also discussed.The indirect electrochemical approach greatly expands the usage of electrochemical method, so that a variety of non-electroactive species can also been determined.
    Simultaneous Qualitative and Quantitative Analyses of Multicomponent System by Stepwise Regression Method
    ZENG Wei, TU Mei-Hua, PANG Yao-Hong, LI Ke-An, TONG Shen-Yang
    1993, 14(4):  472-475. 
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    Principle, experiment and datum treatment method of stepwise regression analysis were introduced.Simultaneous determination for multicomponent mixture was discussed spectropho-tometrically.By using the method, the results obtained from the samples containing several nitrophe-nols are satisfactory.This method is useful when the scope of possible existing components in sample can be known, but how many components are unknown.This method is simple, rapid and reliable.
    Studies on a New Fluorescence Fiber Optic Sensor for Sulfur Dioxide
    ZHU Yuan-Bao, WANG Ke-Min, XU Yuan-Jin, HE Shuang-E, LI Xun
    1993, 14(4):  476-479. 
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    Anew fluorescence fiber optic sensor for sulfur dioxide measurement has been described.Quinine dissolving in internal solution was used as a sensitive material.The internal solution layer was separated from the aqueous solution by a gas-permeable membrane.The response range of the sensor for sulfur dioxide is from 3×10-4 mol/Ldown to 3×10-6 mol/L.Reproducibility, stability, resp-ponse time and selectivity of the new fiber optic sensor are reported.With this sensor, practical samples containing sulfur dioxide were measured.The results are compared to measurments with iodime-try.
    Adsorption Pattern Recognition and Its Application in Adsorptive Polarographic Wave
    WANG Chang-Fa
    1993, 14(4):  480-482. 
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    In this paper, a adsorption equation, βC=[0/(1-0) ]"exp(g'0), is proposed as a general adsorption pattern recongnition, on which we are able to recognize isotherm of the electroactive species adsorbed on electrode, and to estimate adsorption parameters.It was applied to the inverstigation of the adsorptions of T(4-TMAP)Pand CNAon DME, The results show that the former obeys Langmuir isotherm, the adsorption equation is [θ/(l-θ) ]0.96=7.76×106×e-0.240×C, and the latter obeys Frumkin isotherm, the adsorption equation [θ/(l--θ)]1.03=1.18×105×102.220×C, These are consistent with those of literatures.
    The Synergistic Effect Between Quaternary Ammonium Cation and Inorganic Anion for Corrosion Inhibition of Iron
    ZOU Jin-Yun, ZHANG Xu
    1993, 14(4):  483-485. 
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    The synergistic effect between tetra-butylammonium cation (TBA+) or hexadecyl pyridini-um cation (HDP+) and SCN- or I- in 0.5 mol/L H2SO4 for corrosion inhibition of iron was investigated by potentiodynamic and polarization resistance techniques.The results show that the synergistic effect between HDP+ containing π electron construction and inorganic anion is stronger than that between TBA+ and inorganic anion.It was discussed in detail that joint adsorption pattern of cation and anion on the interface of electrode-solution is related to construction and property of ions.
    The Oxidation Colour Reaction of the New Colour Reagent 2,3,7-Trihydroxy-9-dibromo-hydroxyphenyi fluorone and Determination of Cr in Waste Water by Dual-Wavelength Spectrophotometry
    OU Zhong-Ping, LU Xia, PAN Jiao-Mai
    1993, 14(4):  486-488. 
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    The colour reaction between Cr and the new colour reagent 2, 3, 7-trihydroxy-9-dibromo-hydroxyphenyl fluorone was studied by spectrophotometry and potentiometric tilration.It is found that the colour reaction between Cr and the colour reagent (DBHPF) is an oxidation colour reaction in both weak and strong acid media, Based on this colour reaction, a dual-wavelength spectrophotometry for the determination of Cr has been established.Cr(Ⅵ) and total Cr in waste water had been determined by this method.The results and the recovery are satisfactory.
    The Theory of Reversible Wave with Staircase Sweep Voltammetry at Microring Electrodes and Its Experimental Verification
    WU Zhi-Bin, ZHANG Zu-Xun
    1993, 14(4):  489-491. 
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    In this paper, the theory of reversible wave with staircase sweep voltammetry at microring electrodes is derived.The properties of current-potential curves have been discussed in detail.In order to examine the validity of the theory, experimental studies with K4Fe(CN)6 in 0.5 mol/L KCl solution were carried out at platinum and gold microring electrodes.The experimental results are in good agreement with the theoretical ones.
    Studies on Kinetic Spectrophotometric Determination of Trace NO2- by Stopped-flow Injection Method
    ZHANG Gui-Zhu, LIU Shan-Jun, HE Xi-Wen, SHI Hui-Ming
    1993, 14(4):  492-494. 
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    Based on the catalytic effect of trace NO2- on the oxidation of Rhodamine Bby potassium bromate, a new kinetic spectrophotometric method for the determination of NO2- has been developed with stopped-flow injection technique.Beer's law is obeyed for NO2- in the range of 0.24-9.0 ng/ mLand the limit of detection is 2.4×10-10 g/mL.The method has been applied to the determination of NOf in water and the sampling frequency is 60 samples/h with satisfactory results.
    Syntheses and Structure Analysis of Bulkier Substituted Titanocene,Zirconocene, Hafnocene Dichlorides and Ferrocenes
    WANG Jia-Xi, CHEN Shou-Shan, WANG Xu-Kun
    1993, 14(4):  495-498. 
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    Sixteen bulkier substituted titanocene, zircdnocene, hafnocene dichlorides and ferrocenes have been synthesized by the reactions of 6,6-dialkylf ulvenes with aryllithiums followed by treatment with MCl4(M=Ti, Zr, Hf), FeCl2 and (CpTiCl2)2O.Their 1H NMRspectra have been discussed.
    Studies on the Synthesis of Phosphonodipeptides and Their Herbicidal Activities (Ⅳ)
    CHEN Ru-Yu, ZHANG Yue-Hua, CHENG Mu-Ru
    1993, 14(4):  499-503. 
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    In order to look for a new herbicide, a series of novel phosphonodipeptides have been prepared by the reaction of (PhO)2P(O)CHRNH2 with C1CH2CONHCHR'COOR2 in the presence of tri-ethylamine in benzene.The structures of all the compounds prepared were proved by 1H NMR, IRand MSand some of them by elementary analysis.The preliminary biological tests indicated that some of them showed a highly selective herbicidal activity.
    Syntheses and Chelations of N-Ferrocenylimines
    MA Huai-Rang, YANG Bing-Qin, CHEN Zhi-Bing, LI Jing-Song
    1993, 14(4):  504-507. 
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    Nine N-ferrocenylimines and two binuclear complexes have been prepared and characterized by elementary analysis, IR, UV/Vis and 1H NMRspectra.It is found that the condensation of aminoferrocene with ketones or aldehydes is similar to that of primary arylamines with the carbonyl compounds.
    A Study of Mass Spectrometry of 2-Amino-5-substituted-4-thiazolyl Phosphonates
    JIAO Xian-Yun, HU Bing-Fang
    1993, 14(4):  508-511. 
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    The fragmentation characteristic of a series of recently developed 2-amino-5-substituted-4-thiazolyl-phosphonates is studied by using electron impact (EI), electron impact-collision activity-mass analysed ion kinetic energy spectrometry (EI-CA-MIKES) and accurate mass measurment (AMM) techniques.It is found that a new type of γ-alkyl rearrangement has occured as evidenced by the'pres-ence of a molecular daughter ion of ethylated thiazole ring(m/z 203).The molecular parent and daughter ions have been fully identified by their unsaturation, accurate ion mass and elementary constitution.The fragmentation pathway is portrayed in a scheme(see Fig.2)
    Studies on Condensed Heterocyclic Compounds (Ⅷ)——Synthesis and Biological Activities of 3-(α-Naphthylmethyiene)-6-aikyl/aryl-S-triazolo[3, 4-b]-1,3,4-thiadiazoles
    ZHANG Zi-Yi, LI Ming, ZHAO Lan, LI Zheng-Ming, LIAO Ren-An
    1993, 14(4):  512-516. 
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    Fifteen new compounds with the general formula:(这里有图片19930420-512-1.gif)in which ARis CH3, C2H5, C3H7, C4H9, C5H11, 4-XC5H4(X-H, F, Cl, Br, I, CH3, CH3O, NO2), 2-ClC6H4 3-ClC6H4 have been prepared through the cyclization of 3-(α-naphthylmethylene)-4-amino-5-mercapto-1,2, 4-triazoie(3) with aliphatic earboxyhc acids and aromatic carboxylic acids in the presence of phosphorus oxychloride.The structures of the products were proved by 1H NMR, 1R, MSand elemental analysis, it was found that some of these compounds have herbicidai and fungical activities.
    Syntheses and Bioactivities of 4H-1,2,4-triazol-4-yl Ketones and Alcohols
    LIAO Lian-An, CHEN Ming-De, ZHANG Hong-Kui, GUO Qi-Zhen
    1993, 14(4):  517-519. 
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    1-(4H-1,2,4-Triazol-4-yl)pinacolone reacted with alkyl halide for 4 h under the condition of phase transfer catalysis to give 4H-1,2, 4-triazol-4-yl ketones (3) with the yields of 20%-93%.(3) were reduced by KBH4 to afford the corresponding alcohols (4) with the yields of 92%-95%.The preliminary results of bioassay show that (3) and (4) have lower plant growth retarding and fungicidal activities than those of paclobutrazol.
    A Study of Mass Spectra of 4,6-Disubstituted-3-one-5-thione-1,2,4-triazine Compounds
    ZOU Jian-Ping, XU Tian-Lin, LU Zhong-Er
    1993, 14(4):  520-522. 
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    The El mass spectra of eight new 4, 6-disubstituted-3-one-5-thione-1, 2, 4-triazine compounds are reported.Their mass spectral fragmentations are proposed on the basis of high resolution MSand the B/Elinked scan spectra.
    Analysis for Bond Valence in Cluster Compound
    LI Ying, ZHANG Xing-Chen, WU Jian-Jun
    1993, 14(4):  523-526. 
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    Based on the electronic structure and chemical bonding properties of the skeleton-ligand bonds of the skeleton of a cluster compound, having determined the number of empty valence orbitals or lone pair electronic orbitals of the cluster, the number of total bond valence of the skeleton is obtained according to the distribution of the number of valence electrons of the skeleton in valence bonding orbitals of the skeleton, then the chemical bonding properties between neighbouring two atoms in the skeleton can be guessed with the configuration of the skeleton of the cluster compound.
    A Theoretical Study of Excited-State Proton Transfer Reaction of Salicylic Acid and Its Solvent Effect
    FENG Ji-Kang, TENG Qi-Wen, XU Wen-Guo, LI Zhi-Ru, SUN Chia-Chung
    1993, 14(4):  527-531. 
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    With AM1 and INDO/CImethods, a theoretical study of proton transfer reaction for salicylic acid in excited state has been completed.The potential energy curve, barrier, transition state have been obtained.The absorption and fluorescence spectra of related compounds are assigned theoretically.All calculated results are in agreement with experiments.Then the mechanism of photochemical reaction and the possibility of applications are discussed.Finally, the effect of solvent, taking diethyl ether as the example of hydrogen-bonding solvent on the excited-state proton transfer reaction of salicylic acid has been investigated.
    Reduced Extent Method in Studies of Thermokinetics (Ⅲ)——Studies on Thermokinetics of the 2-Ⅰ Reversible Reaction
    LIU Jing-Song, ZENG Xian-Cheng, DENG Yu
    1993, 14(4):  531-535. 
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    On the basis of previous articles, the reduced extent equation and the model of thermokinet-ics for 2-1 reversible reaction, with which both rate constants and equilibrium constant can be calculated simultaneously, are suggested in this paper.The thermokinetics for an endothermic 2-1 reversible reaction system, the acid-catalyzed esterification between acetic acid and methanol in buffer solution (pH=1.5), has been studied with a conduction calorimeter at 30.0 and 40.0℃.The rate constants of forward and backward reactions and equilibrium constants were calculated with the model in this paper, and then, activation parameters of this reversible reaction were obtained.These experimental results, by which the validation of this model has been tested, are discussed in detail.
    Crystal Structures of 1,3,2-Oxazaphospholidine Derivatives
    LIU Xiao-Lan, SUN Ming, MIAO Fang-Ming, YANG Hua-Zheng, SHAO Jiu-Shu, WANG Hui-Lin, CHEN Ru-Yu
    1993, 14(4):  536-539. 
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    The crystal and molecular structures of 2-diethylamino-3-(4'-methylbenzoyl)-2-thione-l, 3, 2-oxazaphospholidine (1) and 2-diethylamino-3-(2', 4'-dichlorobenzoyl)-2-thione-1,3, 2-oxaza-phospholidine(2) were determined by X-ray diffraction method.The diffraction data were collected on a CAD4 single crystal diffractometer.The crystallographic data are as follows; (1) C14H21N2O2PS, orthorhombic, space group Pbca α=0.9057(5) nm, 6=1.3974(6) nm, c=2.5130(7) nm, Z=8, V=3.1806 nm3, R=0.051.(2) C13H17N2O2PSCl2, monoclinic, space group P21/c, α=0.7375(1) nm, 6=1.4370(3) nm, c=l.6015(7) nm, β=93.70(2)°/, Z=4, V=1.6895 nm3, R=0.054.The structures of the two compounds were solved by the direct method.The five-membered oxaza-phospholidine ring has a half chair conformation in both of the molecules.
    Bond Order Conservation Approach to the Mechanism of Decomposition for Formic Acid over Transition Metals
    XIA Wen-Sheng, WANG Nan-Qin, ZHANG Qian-Er
    1993, 14(4):  540-544. 
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    Bond order conservation-Morse potential approach has been used to study the mechanism of decomposition for HCOOHon Ag(111), Ni(111) and Fe/W(110) surface in the two cases of extremely low and higher coverages.The following results have been obtained; In the first case, HCOOHdecomposed via intermediate (HCOO(s)), which proceeds following the order Ag<Ni<Fe/Weasily, over Fe/W HCOOoxidizes the surface and the bond scission of C-Hand C-Ohas a small energy barrier difference.In the second case, the mechanism does not change over Ag, but changes over Ni,Fe/W.Two HCOOHmolecules form a surface complex (HCO(s) * HCOO(s)) with the loss of water and then decompose further.Over Ni the decomposed reactions have low energy barriers and can show an autocatalytic behavior.
    Investigation of Preparation and Catalytic Cracking Property of LaHZSM-5 Zeolite
    LI Rong-Sheng, WEN Rui-Wu, ZHANG Wu-Yang, WEI Quan
    1993, 14(4):  545-547. 
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    In this paper LaHZSM-5 zeolites with varying exchange degree were prepared by the conventional and the hydrothermal liquid-solid exchange.The prepared LaHZSM-5 zeolites were characterized by XPSand IRspectroscopy, X-ray diffraction as well as the cracking of pentadecane.The results show that the LaHZSM-5 zeolite samples with higher exchange degree can be prepared by the hydrothermal exchange.LaHZSM-5 zeolite has a higher cracking activity than HZSM-5 zeolite.After the incorporation of La by exchange, the selectivity for gas is decreased and the selectivity for C5-10 is increased.In addition, the hydrothermal stability of the activity of ZSM-5 zeolite is also enhanced owing to the incorporation of La ion by exchange.
    Kinetics of CO Substitution of M2(CO)10(M=Mn,Re) with Py in the Presence of (p-CH2OC2H4)2TeO
    GAO Yi-Ci, SHEN Jian-Kun, SHI Qi-Zhen
    1993, 14(4):  548-551. 
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    Reported are the rates of reaction and activation parameters for COsubstitution reaction of M2(CO)10(M=Mn,Re) with Py in the presence of (p-CH3OCeH4)2TeO.The rate of reaction is the first order in concentrations of M2(CO)10 and of (p-CH3OC6H4)2TeO, but zero order in Py.One possible mechanism.is suggested for the reaction, which is similar to that proposed earlier for the corresponding reactions with (CH3)3NO as the O-atom transfer reagent.The difference of activities between (CH3)3NOand (p-CH3OC6H4)2TeO is discussed in terms of their basicity in this paper.
    EXAFS Studies of Ni-S Catalyst for Hydrogenation of Oils and Fat
    XIE Jin-Hai, WANG Qi-Wu
    1993, 14(4):  552-554. 
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    The structure of Ni-Scatalyst used for hydrogenation of oils and fat was studied with Ni-Kedge extended X-ray absorption fine structure(EXAFS) speetrophotometry.Tt was found that after the Ni catalyst was poisoned with sulphur, the compound of Ni3S2 was formed, and the 3CNspace of Ni was occupied by S.The addition of sulphur decreased the activity of Ni catalyst, however, it exhibit a high selectivity for the formation of trans-oleate.
    Surface States and Oxidation Activities of MnOx TiO2 Catalysts
    ZHENG Bai-Cun, WANG Ren, ZHOU Jing-Hong
    1993, 14(4):  555-558. 
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    The surface states and COoxidation activities of MnO2/TiO2 catalysts with various loading amount were studied in this paper.The results show that manganese oxide was Mn2O3 when the loading amount of MnO2/TiO2 was Lower than 5.7 wt%, while the loading amount was more than 5.7 wt%, MnO2 existed in the form of Mn2O3 and MnO2. The threshold of Mn2O3 from the dispersed states to crystalline phase on TiO2 was 0.028 g Mn2O3/100 m2.The activities of catalysts were relative to their surface states,and the co-existence of Mn3+ and Mn4+ were contributive to increase the activities.
    Properties of Zeolite-Filled Polyvinyl Alcohol Membrane and Its Application to Catalytic Esterification
    GAO Zi, YUE Ying-Hong, LI Wen-Jim
    1993, 14(4):  559-562. 
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    The composite membrane consisting of zeolites KA,NaA,CaAor NaXand poly vinyl alcohol polymer were prepared.The pervaporation and separation characteristics of different alcohol-water systems through these membranes were investigated at temperatures ranging from 20℃ to 50℃-Distinct improvement on molecular transport and the molacular sieving effect of the zeolites have been observed.The addition of zeolite filler to PVAmembrane appears to improve the flux of the membrane in various alcohol/water systems.The order of the increment of flux is.NaX>CaA>NaA>KA, which runs parallel to the increase in pore size of the zeolites.The separation factor of the zeolite-filled membranes can be increased or decreased depending on the kind of zeolite filled and the size of the alcohol molecule.For CH3OH/H2Oand C2H5OH/H2Osystems, at a higher temperature the flux of the KAfilled membrane is improved, while its separation factor remains unchanged.Hence the performance of KAfilled membrane in the separation of CH3OHand C2H5OHfrom aqueous mixtures is better than that of the unfilled PVAmembrane.The esterification of acetic acid by ethanol is aided by the KAmembrane, and the time required to attain 95% conversion is reduced by 9 h as compared with the unfilled PVAmembrane.For the esterification of salicylic acid by methanol, the addition of KAinto the membrane increases the reaction conversion by 1.2 times as well.
    A Study of the Reaction of C60 with Toluene, Benzyl Chloride and p-Xylene in Gas Phase
    GUO Xing-Hua, LIU Zi-Yang, SONG Feng-Rui, LIU Shu-Ying, ZHANG Fa-Yi
    1993, 14(4):  563-565. 
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    In the ion source of mass spectrometer, the gas-phase C60 reacted with the ion or radical fragments of toluene, benzyl chloride and p-xylene and a series of derivative ions were formed in the gas phase.This indicates the gas-phase C60 has active chemical properties.Among them [C60C7H7]+ and [C60C6H5]+ are the predominant adduct ions.The C7H7+ ions are the mixture of tropylium, benzyl or tolyl ions in the gas phase, therefore the adduct ions [C60C7H7]+ have four possible structures.
    Studies on Propane Oxidative Dehydrogenation over Pure Rare Earth-Based Catalysts
    ZHANG Wei-De, WAN Hui-Lin, CAT Qi-Rui
    1993, 14(4):  566-567. 
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    The pure rare earth-based complex catalysts such as CeO2/2CeF3, La2O3/4CeF3, Sm2O3/ 4CeF3 were prepared.These catalysts were very active in oxidative dehydrogenation of propane, and the selectivity to propene was very high.At 500℃ and 6000 h-1, using CeO2/2CeF3 as the catalyst with Ce2Oas the promoter, the conversion of propane was 41.3%, selectivity to propene reached 81.1%, propene yield was 33.5%.After 84 hours, the catalyst remained activive, the yield of propene still attained 31.7%.
    Studies on the Effect of the Lone Pair Bond Weakening
    NI Shen-Kuan, FENG Ji-Kang
    1993, 14(4):  568-570. 
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    The traditional explanation on the effect of lone pair bond weakening, as the result of inter-electronic repulsions between lone pair electrons on bonding atoms, become void when we compare bond energies of the hydrogen halides, because there are certainly no lone pair electrons on the hydrogen atom to repel the lone pair electrons of the fluorine.In this paper, the reasonable explanation on the effects of lone pair bond weakening by using graphic method of bond parameters is presented.It is considered that the weakening effect is a prime shielding result of lone pair electrons intervening between the bonding electrons and nucleus, rather than the interelectronic repulsions between lone pair electrons on separate atoms.
    A Study of Sensitizing Photopolymerization of Diacetylene Acid in Langmuir-Blodgett Multilayers Film
    BAI Yu-Bai, LI Li-Hua, WANG Ya-Ru, LI Tie-Jin
    1993, 14(4):  571-573. 
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    Tricosa-10,12-diynoic acid is a good Langmuir-Blodgett (LB) film material.It can polymerize under UVradiation.In order to extend the range of the sensitivity of diacetylene acid toward visible light, the cyanine dyes were used as sensitizers.It was embedded in the diacetylene acid mono-layers film.We found that when the films were irradiated by Ar+ laser at 514.5 nm the diacetylene acids multilayers film polymerized and the fluorescence quench of cyanine dyes.Based on these results, the sensitizing photopolymerization mechanism was discussed.
    Preface
    Simultaneous Synthesis of Aspartame and Optical Resolution of DL-Phe-OMe by Thermolysin
    TAO Guo-Liang, ZHUO Ren-Xi, CHEN Zhen-Hua
    1993, 14(4):  574-577. 
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    Using DL-phenylalanine methyl ester as reaction substrate instead of L-phenylalanine methyl ester, aspartame was synthesized in good yield by the catalysis of either thermolysin or the immobilized thermolysin.In addition, optical resolution of DL-phenylalanine methyl ester could be achieved simultaneously in this reaction process.Costly D-phenylalanine methyl ester was also obtained in high yield.In the enzymatic reaction, the effects of reaction conditions on the synthetic yield were studied.Reuse of the immobilized thermolysin was also investigated.The experimental results showed that the immobilized thermolysin has better reuse ability.In comparison with the reaction catalyzed by thermolysin, the reaction catalyzed by the immobilized thermolysin required a longer time, and tile yield is slightly lower.The present work provided an economic and practical method for the preparation of aspartame.
    Toughening of PVC via Blending of Core-Shell Polyacrylic-ester Copolymer and Epoxy Resin
    ZHANG Bao-Long, WANG Shu-Fang, HUANG Ji-Fu, DING Pei-Yuan, DU Zhong-Jie, SONG Mou-Dao, ZHANG Bang-Hua
    1993, 14(4):  578-581. 
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    Core-shell particles for toughening PVCwere prepared by sequential emulsion polymerization of butyl acrylate(BA), methyl methacrylate(MMA) and glycidyl methacrylate (GMA).Blending of these particles and small amounts of epoxy resin, including curing agent and accelerator, together with PVCgives materials with greatly enhanced impact strength at a optimized weight fraction.Dependence of impact strength and fracture morphology of the toughened PVCmaterial upon the variation of blending composition has been evaluated and discussed in terms of the fracture mechanisms.
    Studies on the New Complexing Adsorbents (Ⅱ)——Synthesis and Characterization of Complexing Adsorbents Containing Polyamine and Cupric(Ⅱ) as Template
    WANG Bu-Sen, DING Ze-Ren, LI Wen-Lan, GUO Zhen-Liang, HE Bing-Lin
    1993, 14(4):  582-585. 
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    Aseries of complexing polymeric adsorbents made of cross-linked polyamine and copper (Ⅱ) chloride, acting as template were synthesized through the condensation of epichlorohydrin and te-traethylenepentamine or ammonia in oil disperse system.Characterizations of the sorption for Cu(Ⅱ), Ni(Ⅱ), Co(Ⅱ) and Zn(Ⅱ) transition-metal ions were studied.The results show that the sorption capacity of the kinds of complexing adsorbent for Cu(Ⅱ), Ni(Ⅱ), Co(Ⅱ), Zn(Ⅱ) are 247.80, 123.40, 86.90, 153.30 mg/g respectively.The relative selectivities are in the following sequences.Cu(Ⅱ)>Zn(Ⅱ)>Ni(Ⅱ)>Co(Ⅱ).This order is relatively consistent with the natural order of its stability.
    Glass Transition Temperature of Emulsion Copolymer and Its Theoretical Simulation
    KONG Xiang-Zheng, FU Ren-Jun, LI Hai-Yang
    1993, 14(4):  586-590. 
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    Based on monomer reactivity ratios and monomer partition coefficient, the glass transition temperature (Tg) of emulsion eopolymers of butyl acrylate (BA) and vinyl acetate (VA) was simulated using Johnson's equation, and T8 diagrams versus polymer weight fraction distribution was given.The simulation results, as well as experiments, showed that one Tg was observed for semi-continuous eopolymers, and two well separated Tg's for batch process eopolymers.In semi-continuous eopolymers, Tg's values constantly increase with VAcontent in the eopolymers, and by theoretical simulation of Tg's in batch eopolymers at different conversions, it is shown that the experimentally observed lower Tg, which is moving towards higher temperature zone with VAcontent in copolymerization, represents a BA-rich copolymer mainly formed in an early stage of the copolymerization, while the higher Tg, representing a nearly PVAhomopolymer and unaffected by monomer ratio variation in copolymerization, is mainly produced at a later stage of the copolymerization after BAexhausted.The theoretical simulation agrees well with experimental results.
    Studies on TiCl4/Al2Et3Cl3/Y Zeolite High Effective Catalytic System for Copolymerization of Ethylene and Propylene
    WANG Li, FENG Lin-Xian, XU Jim-Ting, YANG Shi-Lin, FENG Zi-Xian, XIAO Fei
    1993, 14(4):  591-592. 
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    In this paper, catalytic system TiCl4/Al2Et3Cl3/Yfor copolymerization of ethylene and propylene was studied by using IRand ESRtechniques.For the first time, it was found in TiCl.,/ Al2Et3Cl3/Ysystem there was one liquid catalytic species in solid phass.High catalytic effeciency reached to 10.2 kg P/g Ti·h when T=50℃, Al/Ti=50, P=101.325×103 Pa.
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