Loading...
CJCU

Table of Content

    24 March 1995, Volume 16 Issue 3
    Previous Issue    Next Issue
    Articles
    Covalendes of Cr in Cr(CO)6and(CO)4ICrCCH3
    YI Xiang-Hui, LI Le-Min, XU Guang-Xian
    1995, 16(3):  329-333. 
    Asbtract ( )   PDF (2430KB) ( )  
    Related Articles | Metrics
    The electronic structures and bonding of Cr(CO)6 and(CO)4 ICrCCH3 were studied with the methods of DV-Xa SCC and natural bond orbitals(NBOs),and then the covalencies of Cr in these two compounds were discussed on the basis of the new difinition of covalence proposed by one of the authors.The results show that there exists a Cr-Ccarbyne triple bond in which σ bond is localized and two π bonds are partially delocalized to carbonyls;on the other hand,there is no back donation of charges from the central chromium atom to the carbyne carbon atom,so the carbyne carbon possesses lower electronic density than carbonyl carbon and methyl carbon in the same molecule,which is consistent with 13CNMR spectrum. The covalencies of Cr in both ompounds are 12.
    Research on the Synthesis of New Silver Cluster Complexes by the Insertion Reaction of CS2into Ag──S Bonds(Ⅲ)── Formation and Crystal Structure of a Trinuclear Silver Cluster Complex Ag3(Pr3iC6H2S)3(PPh3)3·(CH3)2CHOH
    JIN Xiang-Lin, TANG Ka-Luo, LIU Wei-Dong, TANG You-Qi
    1995, 16(3):  334-337. 
    Asbtract ( )   PDF (383KB) ( )  
    Related Articles | Metrics
    The title complex was prepared through the reaction of(PPh3)2Ag(S2CSPr3iC6H2)formed by inserting of CS2 into Ag-S bond of Ag(SPr3iC6H2) in the presence of PPh3 with CH2Cl2-PriOH under mild conditions.The colorless block crystal belongs to the trigonal system with space group R3,a=2.7886(11)nm,c=1.0798(5)nm,V=5.796(4)nm3,Dc=1.2859.cm-3,Z=3.The final Ris 0.060 for 1753 reflections (F>4.0σ(F)).The core of the title compound can be considered as a planar six-membered cycle Ag3S3 of alternating silver and sulfur atoms. In addition,there exists a PriOH molecule in the unit cell.
    Synthesis and Characterization of AlPO4-12 Molecular Sieve from H3PO4-i-C3H7OAl-H2NCH2CH2NH2-HOCH2CH2OH System
    GAO Qiu-Ming, LI Shou-Gui, XU Ru-Ren
    1995, 16(3):  338-341. 
    Asbtract ( )   PDF (2378KB) ( )  
    Related Articles | Metrics
    Hydrothermal crystallization of aluminophosphate molecule sieve(ALPO4-12)was carried out from H3PO4-i-C3H7OAl-H2NCH2CH2NH2-HOCH2CH2OHsystem,Using aluminum triisopropoxide and phosphorous acid (85 wt%)as the aluminum and phosphoroussources.The influences of some main factors(pH,the ratio of P2O5/Al2O3 and the aluminum and phosphorous sources,etc.) on the resulting structure were studied.The product was characterized by means of X-ray powder diffraction,scanning electron mieroscope,infrared spectroscopy,differential analysis and thermogravimetric analysis. The results of investigating the crystallization of AlPO4-12 from non-aqueous system were preliminarily summarized.We found that the organic template,H2NCH2CH2NH2,had two different kinds of environments:one interacted with the skelton by weak hydrogen-bond,the others interacted with the skelton by strong hydrogen-bond.
    A Kinetics Study on Cu2+Transport Across Macroclic Dioxotetraamine Liquid-Membrane in the Presence of Ni2+
    GAO You-Liang, FAN Fu-Long, SHEN Meng-Chang, LUO Qin-Hui
    1995, 16(3):  342-345. 
    Asbtract ( )   PDF (307KB) ( )  
    Related Articles | Metrics
    We studied the liquid membrane transport rate of Cu2+in the presence of Ni2+in chloroform-n-octanol solution of 12-octadecyl 1,4,7,10-tetraazacyclotridecane-11,13-dione (ODT)as the ion carrier. The results show that the transport is supported by neutral complexes and independent of the anion and the presence of Ni2+does not affect the transport.
    Synthesis, Characterization and Acid-Base Properties of Layered Double Hydroxides Pillared with Tungstosilicate Anions
    GUO Jun, SUN Tie, SHEN Jian-Ping, LIU Dan, DANG Da-Zhen, MIN En-Ze
    1995, 16(3):  346-350. 
    Asbtract ( )   PDF (371KB) ( )  
    Related Articles | Metrics
    Layered double hydroxides(LDHs) pillared with heteropolyanions,SiW11M·(H2O)O396-(Mis the first row transition metals),were synthesized by means of direct ion-exchange reaction and were characterized by elementary analysis,XRD,IR and DTA.The results show that the interlayer space of the pillared products increase from 0.92 nm to 1.47 nm,and there is an increase in the thermal stability of the pillared product with the heteropolyanion intercalating into the LDH. The pillared prodticts shows the acid-base bifunctional catalysis over the isopropanol conversion,and the acidity is relatively stronger.
    Solid Transformation of Amofphous Silica on Surface of Silicalite-1
    GUO Jun, SUN Tie, SHEN Jian-Ping, LIU Dan, DANG Da-Zhen, MIN En-Ze
    1995, 16(3):  351-353. 
    Asbtract ( )   PDF (225KB) ( )  
    Related Articles | Metrics
    Solid transformation of amorphous silica was completely carried out on the surface of silicalite-1 in a hydrothermal system with an organic template. The solid transformation was proved by characterization of powder XRD, FTIR of zeolite framework,sorption rate and isotherms.
    Determination of Stabiliyt Constants of Complex by Using Numeric Genetic Algorithm
    LI Tong-Hua, ZHANG Zhong-Jie, ZHU Zhong-Liang, DING Lin, LI Guang-Sheng
    1995, 16(3):  354-358. 
    Asbtract ( )   PDF (422KB) ( )  
    Related Articles | Metrics
    Anovel global optimal method-numeric genetic algorithm(NGA) is proposed in this paper.NGA can deal with the optimization of continuous variables. NGA can alsofind global optimal in the presence of many local optimal and is especially suitable to deal with complicated nonlinear problem. Individual and population are varied by genetic operations to gradually adapt the environment. Besides crossover and mutation, a new genetic operation-memory is proposed in this paper to shrten the calculating time. The stability constants of trichlorosalicylic acid and its complexes of copper and iron have been calculated by using NGA.
    Tyrosinase Amperometric Biosensor for Monitoring Inhibitor of Low Concentration of Cyanide
    HU Xiao-Ya, LENG Zong-Zhou
    1995, 16(3):  359-362. 
    Asbtract ( )   PDF (390KB) ( )  
    Related Articles | Metrics
    Cyandide inhibitor of tyrosinase was determied with biosensor of tyrosinase by using tyrosinase immobilized on a preactivated polyaminde membrane.Phenol with the range of concentration 5×10-6～4×10-5mol/Lwas chosen as substrate in phosphate buffer.The de-crease of substrate response have linear relation with square root of concentration of CN-with detection range of 5×10-7～2×10-4mol/L. The fine selectivity and reproducibility were obtained.
    Preface
    Studies on Solid Surface-Delay Fluorescence of Pipemidic Acid
    JIN Wei-Jun, CHEN Su-E, FAN Yan-Ping, LIU Chang-Song
    1995, 16(3):  363-367. 
    Asbtract ( )   PDF (353KB) ( )  
    Related Articles | Metrics
    The solid surface-delayed fluorescence of pipemidic acid was studied. The experiments indicate that inorganic salts,Be(Ⅱ),Mg(Ⅱ),Ca(Ⅱ),Sr(Ⅱ),Ba(Ⅱ) and Zn(Ⅱ),Cd(Ⅱ),La(Ⅱ)etc., can enhance greatly the luminescence signal.The pHvalue has an obvious effect and the maximum luminescence signal can be obtained at pH 11.3 The measurements of lifetime indicates that PPA decays in the diexponential in the solid surface. The lifetimes are 2.79 ms and 1.70 ms, respectively. The low temperature spectra of PPAwere measured and the inorganic salts can also greatly increase low temperature luminescence signal.In this paper, the linear dynamic range of the analytical curve of PPAits 1.8ng-1800 ng/spot.
    Articles
    Electrocatalysis of Poly-thionine Modified Microband Gold Electrode for Oxidation of Reduced Nicotinamide Adenine Dinucleotide
    CAI Chen-Xin, JU Huang-Xian, CHEN Hong-Yuan
    1995, 16(3):  368-372. 
    Asbtract ( )   PDF (395KB) ( )  
    Related Articles | Metrics
    The electrocatalytic oxidation of NADH in phosphate buffer solution (pH=7.0)by poly-thionine modified microband gold electrode was investigated.The electrochemical polymerization of thionine in acetonitrile solution and the properties of the resulting films were studied.It was found that the addition of acids such as CF3COOH to the medium markedly facilitates the film formation.The poly-thionine film was characterized by IR spectra.Two redox couple of poly-thionine in the potential range of -0.7─+0.5 V (vs.SCE)were observed,one of them possesses the monomer-type activity.The peak potentials are Epc1=-0.03 V,Epa1=0.05 V;Epc1=-0.24 Vand Epa1=-0.17 V (vs.SCE,25℃). Aslope of-29 mV/pH for the plot of Eovs. pHwas observed in acidic solution,whereas in alkaline solution the slope was -56 mV/pH.
    Voltammetric Studies on the Barium (Ⅱ)Ion Transfer Across a DCE/W Microinterface Assited by DB18-C-6
    YU Ba-Zhang, HUANG Eo, WU Shu-Fang, LI Pei-Biao
    1995, 16(3):  373-376. 
    Asbtract ( )   PDF (2375KB) ( )  
    Related Articles | Metrics
    The electrochemical behavior of Ba2+ion transfer assisted by DB18-C-6 has been studied in detail by using the dual-section liquid/liquid interface microelectrodes.The experimental results demonstrated that the process was reversible,diffusion-controlled and abided by TICmechanism.Trace Ba2+was analyzed together with DB18-C-6 which was difficult to determine by other methods.
    A Fiber-Optic Reflacted Iron Sensor with Amberlyst A-27 as a Substrate
    LU Jian-Zhong, ZHANG Zhu-Jun
    1995, 16(3):  377-379. 
    Asbtract ( )   PDF (229KB) ( )  
    Related Articles | Metrics
    Afiber-optic iron reflected sensor has been developed by immobilizing pyrocatecholdisulfonic acid on Amberlyst A-27.The formation of the FeHLcomplex between iron ion and immobilized pyrocatedisulfonic acid caused a large reflected intensity change at 485 nm,which was due to a sharp change in colour of the reagent phase from white to violet,and iron ion in the solution can be determinated.The sensor has a higher sensitivity as well as good reversibility and has been applied to the determination of water samples. The reaction mechanism was also preliminary studied.
    One-Electron Oxidation of Aceanthracene and 9-Methylaceanthracene
    LI Zhao-Zhao, Laren M. Tolbert
    1995, 16(3):  380-383. 
    Asbtract ( )   PDF (284KB) ( )  
    Related Articles | Metrics
    The oxidation of aceanthracene and 9-methylaceanthracene by pyridine/iodine in chloroform was studied.During the initial electron transfer,the radical cation of aceanthracene underwent predominantly deprotonation of ethylene,less nucleophilic attack by pyridine.The crystal structure of aceanthracene-pyridinium adduct was determined by X-ray diffraction method.In the case of 9-methylaceanthracene,deprotonation leading to sidechain oxidation was the sole procedure.Deprotonation of ethylene was much more rapid than that of methyl. No trace ring-oxidation is observed.
    Studies on the Analysis of β-blockers and Their Metabolites in Urine by Gas Chromatography (Ⅲ)──Analysis of Five β-Blockers and Their Metabolites in Rat'Urine by Solid-phase Extraction and GC/MS
    XU You-Xuan, SHEN Li, WANG Shan, WU Yun, ZHANG Chang-Jiu
    1995, 16(3):  384-386. 
    Asbtract ( )   PDF (307KB) ( )  
    Related Articles | Metrics
    Aprocedure for detecting β-blockers was establ ished.Five β-blockers were administrated to rats. The rats' metabolic urine tqamples were hydrolysed with β-glucuronidase,extracted by Sep-Pak C18 columns,and analyzed by GC/MS.Their metabolites were identified by mass spectra and metabolic theories.The recoveries of the drugs were all over 75%.The hydrolysed metliods were compared and the mass fragmentation mechanism was discussed.
    Syntheses and Structures of Cyclic Complexes Me2Si[η5-C5H4Fe(CO)2]2SnR2
    XIE Wen-Hua, ZHOU Xiu-Zhong, XU Shan-Sheng, WANG Ru-Ji, WANG Hong-Gen
    1995, 16(3):  387-390. 
    Asbtract ( )   PDF (350KB) ( )  
    Related Articles | Metrics
    The cyclic compounds of Me2Si[η5-C5H4Fe(CO)2]2SnR2[R=Cl(1),Me(2),Ph(3)] were synthesized via insertion of SnCl2 to Fe-Fe bond of complex 1,Me2Si[η5-C5H4Fe(CO)]2(μ-CO)2 and the reactions of the related dianion {Me2Si[η5-C5H4Fe(CO)2]2}2-with R2SnCl2(R=Me,PH).They were characterized by IR,1H NMR and elementary analysis. No expected product was isolated from the corresponding reactions of complex 2,(η5,η5C5H4SiMe2OSiMe2H4)[Fe (CO)]2(μ-CO)2.The crystal structure of 3 was determined by X-ray diffraction. The crystals of 3 are monoclinic,space group P21/n with a=1. 0384(3)nm,b=1.6384(1) nm,c=1.5762(5) nm and β=97.93(2)°,V=2.656(2) nm3,Z=4,Dx=1.71g/mL.The final agreement factor,R=0.036.
    Studies on the Syntheses and Biological Activties of trans-Cyclothiophosphorylthioureas
    SHAO Rui-Lian, YANG Guang-Fu, MIAO Wei-Shi, LI Guang-Ren
    1995, 16(3):  391-394. 
    Asbtract ( )   PDF (300KB) ( )  
    Related Articles | Metrics
    Thirteen new trans-cyclothiophosphorylthiourea derivatives,R1R2NC(S) NHR3(R1=H,alkyl;R2=alkyl, substituted plienyl;R3=4-phenyl-5,5-dimethyl-2-sulfo-1,3,2-dioxaphosplioranyl),were synthesized by the addition reaction of frans-2-isothiocyano-4-plienyl-5,5-dimethyl-2-sulfo-1,3,2-dioxaphosphorinane to various amines respectively and their structure were confirmed by means of elemental analysis,1HNMR and IR. The biological activities of all new compounds were tedsted preliminarily and the results indicate that some compounds showed fungicidal activity and plant-growth reguiarity activity. In addition,the stereochemistry of the reaction between 2-chloro-4-phenyl-5,5-dimethyl-2-sulfo-1,3,2-dioxaphosphorinane and potassium thiocyanate was reported for the first time.
    Preparation and Pseudorotation of Alkoxyphosphoranes
    LIU Lun-Zu, LI Guo-Wei, ZHANG Ao, ZENG Xing-Zhong, FU Lan-Bing
    1995, 16(3):  395-398. 
    Asbtract ( )   PDF (305KB) ( )  
    Related Articles | Metrics
    Reaction of hydridophosphoranes 2 with benzensulfenic esters 3 provides a series of substituted spirobicyclic alkoxyphosphoranes 4.The pseudorotation process of compound 4 was observed by the variable temperature 31PNMR spectra. The free energy of activation for this process was calculated. Coalescence for 4a,4boccurred at 130℃ ,4cand 4dat 140℃.The △G≠ for 4a,4b,4c,4dare 81.8,81.8,85.8,84. 99kJ/mol,respectively.The results have indicated that pseudorotation process is subject to steric infltiences.
    Studies on Semisynthetic Cephalosporins and Penicilins Derivaties
    ZHANG Zi-Yi, YANG Feng-Ke, GUAN Zuo-Wu, HAO Chao-Qing
    1995, 16(3):  399-404,401. 
    Asbtract ( )   PDF (371KB) ( )  
    Related Articles | Metrics
    Nine derivatives of 7β-(5-aryl-2H-tetrazolylacetamido) cephalosporins were synthesized by acylation of 7β-amino group of 7-ACA,7-ADCA with 5-aryl-2H-tetrazolyacetyl chlorides. In the same way,two new 7β(2-phenyl-4-quinolincarboxamido) cephalosporins and two new 6β-acyl-amino penicillins derivatvies were ohtained. Isolation and purification of the thirteen compounds were ftilfliled with Sephadex G-15 column chromatography andcentrifugal-TLC technique. The structures of new compounds were confirmed by elementary analysis,IR and 1HNMR.
    Structures and Liquid Crystalline Properties of Monoarmed Crown Ethers
    QIN Jun, XIE Ming-Gui, HU Zi-Lun, JIANG Qing, ZHAO Hua-Ming
    1995, 16(3):  405-409. 
    Asbtract ( )   PDF (2452KB) ( )  
    Related Articles | Metrics
    With the aid of CPK molecular model,three monoarmed alicyclic crown ether containing 15-crown-5 unit liquid crystals (1-3) were first synthesized.The transition temperatures were TKSc*-7.5 TSc*N 18.2 TNI23.6 for 1,TKI91.1 TIN82.6TNSc*70.4 TSc*K 50.3 for 2and TKC 33.87 TCN 46.7 TNI 64.4 for 3. The relationship between structures and properties was investigated,which revealed that monoarmed crown ether liquid crystals could possess mesomorphism not only when the ratio of molecular length to diameter was larger than 3,but also the molecular plarity was required.By inserting chiral group,chiral smetic phases were resulted.It is worth mentioning that the synthesis of crown ether liquid crystals with chirality is hitherto also a new attempt.
    The Effect of Divalent Metal Inos on the Interaction Between Pingyangmycin and DNA
    WANG Zi-Chun, HUANG Deng-Yu, YUAN Jing-Ming
    1995, 16(3):  410-412. 
    Asbtract ( )   PDF (215KB) ( )  
    Related Articles | Metrics
    Pingyangmycin is an antitumor antibiotics. The therapeutic activity is to degrade template DNA or interfer DNAbiosynthesis. It is necessary for the degradation of DNA to have O2and a metal ion. However,the effect of divalent metal ions on the interaction between Pingyangmycin and DNA is quite different from those of various ions. In this paper, we reported the effect of Fe2+, Co2+, Cu2+, Zn2+and Mg2+etc. on DNA clevaged by Pingyangmycin with agarose electrophoresis and CDspectra. The results showed that the degradation of DNAin the presence of Pingyangmycin was obviously increased by Fe2+or Co2+and inhibited by Cu2+, Zn2+or Mg2+. Meanwhile, the possible mechanism of the two kinds of divalent metal ions for the interaction between Pingyangmycin and DNA was also discussed.
    A Theoretical Study of the Structure and Electronic spectra of C60CH2
    TENG Qi-Wen, FENG Ji-Kang, SUN Jia-Zhong
    1995, 16(3):  413-418. 
    Asbtract ( )   PDF (642KB) ( )  
    Related Articles | Metrics
    The INDO series methods are used to study the two structures of C60CH2:one is of C2v geometry with a bridging CH2 across the bond between two fused six-membered rings in C60;another is Cs geometry with a bridging CH2 across the bond shared by a five-and a six-membered rings. From the calculated results,including total energy,LUMO-HOMO energy gap,the most stable isomer of C60CH2 should be tlie C2v geornetry. Our calculations also find that this C2v isomer has a cyclopropane-like structure(bridging C15─C30 bond length is 0.1556 nm, the bond-order is equal to 0.8663).The calculated result of electronic spectrum of the C2v geomety is in good accordance with experimental result.
    Second-Harmonic Generation form Hemicyanine Derivative Langmuir-Blodgett Monolayers Deposited with Halide Salts in the Subphase
    MA Shi-Hong, LU Xing-Ze, HAN Kui, ZHENG Jia-Biao, WANG Wen-Cheng, ZHANG Zhao-Kui
    1995, 16(3):  419-423. 
    Asbtract ( )   PDF (378KB) ( )  
    Related Articles | Metrics
    Anew hemicyanine derivative E-N-docosyl-4-[2-(4-diethyl-aminopheny) ethenyl]pyridinium bromide(DAEP),was adopted to investigate the effects of KIin the subphase on pure and mixed DAEP monolayers by π-A, UV-Vis absorption and second harmonic generation(SHG) measurements, as well as the physical mechanisms were involved. We found that with increasing KIconcentration in the subphase,an enhancement of the effective molecular hyperpolarizabilityβwas always associated with a red-shift of the absorption peak in both pure and mixed DAEP monolayers. Charge distribution change and reduction of the excited state energy result in a second harmonic resonant effect were one of the main mechanisms responsible for the enhancement of the effective molecular hyperpolarizability in DAEP Langmuir-Blodgett monolayers.
    DV-Xα Embedded Cluster Studies on Chemisorptions of CO, NO and O2on NiO(100) Surface
    LU Xin, XU Xin, WANG Nan-Qin, ZHANG Qian-Er
    1995, 16(3):  424-427. 
    Asbtract ( )   PDF (333KB) ( )  
    Related Articles | Metrics
    The chemisorptions of CO, NO and O2 on the cation siteof NiO(100) surface have been studied by means of DV-Xα embedded cluster model calculations. Two competitive effects have been found in the chemisorption systems: one is the electrostatic interaction and the other is σ/π donation/back-donation bonding mechanism. The former effect for the chemisorbed XO molecules follows the order: CO>NO>O2, while the latter effect follows NO>O2>CO. We conclude that the COchemisorption is mainly electrostatic, while both effects contribute comparatively to the NO or O2 cheniisorptions. The IR behaviour of chemisorption molecules is also explained qualitatively.
    Studies on IR and UV-Vis Spectra Of Ti-Si Zeolites Treated by Adsorption
    XIA Qing-Hua, GAO Zi, CHEN Guo-Hui
    1995, 16(3):  428-431. 
    Asbtract ( )   PDF (304KB) ( )  
    Related Articles | Metrics
    Ti-Si zeolites treated by adsorption of H2O, H2O2and allyl chloride have been carefully studied by using IR and UV-Vis spectra. It is observed that the adsorption of aqueous H2O2can cause a decrease of the 960 cm-1band of Ti-Si zeolites IR spectra, and a weak band is formed at 880 cm-1which is in the range of -O-O-vibrations reported for Ti peroxo complexes. Furthermore,in the UV-Vis spectra, the H2O2treatment results in the formation of electronic transition band at 425 nm. The 425 nm band is in agreement with 420 nm band of Ti hyroxyperoxo compound, which is ascribed to Ti peroxo species.At that case,if allyl chloride is subsequently adsorbed on the surfaces of Ti-Si zeolites preadsorbed with H2O2, the strength of IRband around 880 cm-1and UV-Vis band at 425 nm will all decrease. Meanwhile,a new IRb and is emerging around 980cm-1.It is suggested that the skeletal lattice titanium may play an active site role in the oxidation using H2O2as the oxidant.
    A Study of Surface Oxygen Species from La-Me-O (Me=Mg, Ca,Sr, Ba) Catalysts for Methane Oxidative Coupling
    WU Bo, YUAN Song-Yue, YU Zuo-Long
    1995, 16(3):  432-436. 
    Asbtract ( )   PDF (384KB) ( )  
    Related Articles | Metrics
    CO2-TPD was used to study the surface basicity of La-Me-Omixed oxides and O2TPD, CH4-TPD were employed to study the surface active oxygen species. Comparing the CO2-TPD with O2-TPD, we can see that the basicity of catalyst is in parallel with the catalystic activity. The stronger basicity is more profitable for the catalyst to adsorb oxygen to form active oxygen species and to activate CH4by breaking a C-Hbond. By comparing the catalytic activity. the results showed that La-Ba-O(La/Ba=7/3) catalyst had the strongest basicity, and it gave the highest CH4conversion and C2selectivity. The results from the pulse reaction showed that the lattice oxygen participated in the OCM reaction without gas oxygen, and it was the selective oxygen species.
    Characterization of Oxides and Halogenides of Cerium by ESCA(Ⅱ)──Auger Peaks of CeM5N45N45
    HU Gang, GE Liao-Hai, SUN Gui-Fen
    1995, 16(3):  437-439. 
    Asbtract ( )   PDF (318KB) ( )  
    Related Articles | Metrics
    The larger chemical shift of cerium compounds was discoveried. The chemical states of the cerium compounds were identified by the chernical shifts of Auger energy. The changes in Auger energy and parameters are principally due to the changes in extra-atomic relaxation or polarization energy. The increase of the polarizable properties inanions of cerium compounds corresponds to the increase of Auger energy and parameter. The Auger parameter can be measured more accurately. Ce(CF3COO)xCl3-xwas also studied by ESCA. Itis shown that the electron density at cerium atom increases with the increase of x, while theelectron density at oxygen atom decreases.
    An Investigation in the Sintering Behaviour of Super Fine Sponge-Nickel
    FAN Chong-Zheng, WU You-Shi, LI Jian-Min
    1995, 16(3):  440-443. 
    Asbtract ( )   PDF (319KB) ( )  
    Related Articles | Metrics
    Super fine sponge-Ni material was obtained by the method of chemistry, which has the surface area of 74. 7m2/g and average of particle size of 2-5nm. After sintering in the range of 375～600℃ and in different gases at each time interval, the samples were taken out and instrumental methods of SSA, SEM, TEM, XRD were used to detect their sintering extents respectively. It is found that the sintering takes place at 400℃ evidently; sintering reduces the surface area, increases the particle size, and develops crystallization: and that in different gases the SSA follows the order: He<N2<H2In the present work the sintering rate equationis established. it is advanced that during the initial fast sintering stage,the main mechanism is particle migrationi while at the following slow sintering stage,the main mechanism is atom migration. The accompanying phenomena in sintering process are discussed also.
    Theoretical Study on Vibrational State-Selected Rate Constants of the Reaction C2H2++H2→C2H3++H
    YU Hao, LIU Ruo-Zhuang, LI Zong-He, MA Si-Yu
    1995, 16(3):  444-448. 
    Asbtract ( )   PDF (347KB) ( )  
    Related Articles | Metrics
    The reaction path of the reaction C2H2++ H2→C2H3++Hhas been traced by Fukui's theory of intrinsic reaction coordinate by using an ab initio MO method with the gradient technique. Furthermore, the dynamical properties along the reaction path and CVT rate constants with correction of tunneling effect and effect of curvature have been investigated by reaction path Hamiltonian theory and variational transition state theory. On this basis,the enhancement of rate constant by vibrational excitation of C-C stretching mode has beencalculated. The calculated vibrational enhancement is of the same order of magnitude with the experimentally estimated value.
    Studies on Catalysis of Ferrosilicates for OxidationDehydrogenation of Ethylbenzene ──Effect of Exchanged Cations and Hydrothermal Treatment on Actlvity
    ZHANG Chun-Lei, WU Zhi-Yun, KAN Qiu-Bin
    1995, 16(3):  449-453. 
    Asbtract ( )   PDF (412KB) ( )  
    Related Articles | Metrics
    The catalytic activity and selectivity of FeZSM-5 catalysts for oxidation-dehydrogenation of ethylbenzene(EB) were examined at 823K and EB:O2=1. 0. The influence of exchanged cations, hydrothermal treatment and dispersity of Fe2O3on oxidation-dehydrogenation activity of EB over FeZSM-5 was also studied. XPS, ESR and TPR techniques were used for the determination of states and properties of iron in FeZSM-5. The results indicate that framework iron and highly dispersed nonframework iron used as Lewis acidic sites and basic sites with suitable strength construct the active centers of EBoxidation-dehydrogenation.
    The XPS Study of Complex Oxides Eu0.5RE0.5Fe0.5Mn0.5O3
    REN Xiao-Lin, LI Li-Ping, WEI Quan
    1995, 16(3):  454-458. 
    Asbtract ( )   PDF (391KB) ( )  
    Related Articles | Metrics
    Complex oxides replaced by rare earth ions, Eu0.5RE0.5Fe0.5Mn0.5O3(RE=La, Pr,Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb) were prepared by the solid state reaction method.Measurements by XRD and XPS were carried out. The study of XPS indicates that the replacement by rare earth causes the decrease of the binding energy(B. E. )of rare earth ions,compared to their sequioxides. And in the replaced oxides, the binding energy of Fe2p3/2and Mn2p3/2 increases with the decrease of ion radius of REion. The reasons for the changes of B.E. are discussed.
    Catalytic Behaviour of Oxidative Coupling of Methane over Solid Solution (Bi2O3)0.8(La2O3)0. 2Irradiated by Microwave
    CHEN Chang-Lin, HONG Pin-Jie, DAI Shu-Shan, KAN Jia-De
    1995, 16(3):  459-460. 
    Asbtract ( )   PDF (170KB) ( )  
    Related Articles | Metrics
    The catalytic behaviour of oxidative coupling of methane over solid solution (Bi2O3)0.8(La2O3)0.2under microwave irradiation was investigated. Compared with the classical method, the application of microwave irradiation appears to have beneficial effects: (1)When methane conversion reaches the sarne level, under microwave irradiation, the temperature of catalytic bed is much lower than conventional heating mode. We propose that this is due to "microwave hot spot effect" which generated by localized coupling of microwave energy to point defects or weak-bond surface, and the "microwave hot spots" are just the activecenters for the production of methyl radicals. (2) Under microwave irradiation, CO2can be suppressed to some extent at lower methane conversion level, while CO can be suppressed to some extent at higher methane conversion level. (3) Under microwave irradiation, the ratio of C2H2/C2H6was lower, while C2-selectivity was higher.
    Studies on the Acidity-Reducibility and Catalytic Properties of NiHY Zeolites
    FU Jun, ZHU Chong-Ye, LI Quan-Zhi
    1995, 16(3):  461-463. 
    Asbtract ( )   PDF (236KB) ( )  
    Related Articles | Metrics
    The structure, acidity, reducibility of Ni2+.and the reaction of toluene conversion of NiHY zeolite have been studied by using XRD, NH3-TPD, Py-IR, TPR and toluene conversion reaction. It is found that both the number and the strength of acid sites on NiHY zeolite increase with increasing nickel content, and the number of Bronsted acid sites decrease,while the number of Lewis acid sites increase. Otherwise, there are two peaks of H2consumption, in the range of 573-673-Kand 973-1073 K, respectively, which appear in TPR spectra of NiHY zeolite, and their area increases with the increase of nickel content. The results of the reaction of toluene conversion over NiHYzeolite indicate that the products of aromatic ring opening and dernethylation increase markedly, while the product of disproportionation decreases greatly with the increase of nickel content in NiHY. Associated with the data of acidity and reducibility of Ni2+, the change of the selectivity of toluene conversion over NiHY zeolite has been discussed.
    Activity and Osmotic Coefficients of the Ternary System NaCl-Me4NCl-H2O at 298. 15 K
    YAN Wei-Dong, YAO Jia, HAN Shi-Jun, XU Yi-Jin
    1995, 16(3):  464-466. 
    Asbtract ( )   PDF (199KB) ( )  
    Related Articles | Metrics
    Activity coefficients of NaCl in aqueous mixture of NaCl and tetramethy lammonium chloride were determined by EMF measurements at 298. 15 Kand at eight differ ent ionic strengths from 0. 1 to 2. 5 mol/kg. The data were fitted using the Scatchard, Pitzer and Lim equations. Osmotic coefficients, excess Gibbs free energies of mixing and activity coefficients of Me4NCl were calculated at all ionic strengths.
    The Viscositic Property of Polyethylene Glycol Solution
    SUN Hong-Yao, CHENG Rong-Shi
    1995, 16(3):  467-470. 
    Asbtract ( )   PDF (307KB) ( )  
    Related Articles | Metrics
    The generalized intrinsic viscosity-molecular weight equations in the forrn of [n]=kθ[A+(1+AB)M1/2+BM] for polyethylene glycol in tetrahydrofuran and water were deduced by intrinsic viscosity, vapor pressure osmometry and size exclusicn chromatography methods:25℃:[η]=0.126(1+0.004M1/2)(5+M1/2) H2O, 35℃: [η]=0.140(1+0.004M1/2)(3.5+M1/2)
    Synthesis and Phase Behavior of 1,3-bis-(Mesogenes)-1, 1, 3, 3-tetra Methyldisiloxanes
    ZHANG Xian-Liang, ZHANG Jian-Qiang, WANG Cheng-Rui, ZHUO Ren-Xi
    1995, 16(3):  471-476. 
    Asbtract ( )   PDF (448KB) ( )  
    Related Articles | Metrics
    Sixteen 1, 3-bis-(mesogens )-1, 1, 3, 3-tetramethyl disiloxanes ( Ia,bⅢa-g, Ⅲj,IVa-f) were synthesized. Their chemical structures were confirmed by 1HNMR, IR, UV and elemental analysis. Their phase behaviors were also investigated by using differential scanning calorimeter(DSC) and polarizing microscope. The results show that twelve compounds exhibit the liquid crystalline (LC) plase transition temperatures except four cornpunds(Ⅱa.b,Ⅲd, IVd). X-ray diffraction has been used to investigate the crystal structure of 1, 3-bis-(4-methylazobenzene-oxy-methyl)-1, 1, 3, 3-tetrametbyl disiloxane (Ⅱa). The influence ofchemical structures of these novel siloxane compounds on LC phase behaviors were discussed.
    Particle Morphology and Film Structure in Seeded Emulsion Polymerization
    KAN Cheng-You, DU Zong-Hua, LIU Man-Hong, LUO Dong, KONG Xiang-Zheng
    1995, 16(3):  477-480. 
    Asbtract ( )   PDF (385KB) ( )  
    Related Articles | Metrics
    Homopolymer latexes of polyvinyl acetate (PVA) and polybutyl acrylate(PBA)and their seeded latexes using respectively PVA and PBA as seed were prepared by emulsion polymerization. In order to investigate particle morphologies of various seeded latexes, a selective staining technique using phosphotungstic acid(PTA) under transmission electron microscopy (TEM) observation as well as particle surface property characterization by soap titration were used. It was shown that latex particles of type PBA-PVA core-shell could be well formed by pouring VAmonomer into PBAseed latex, and that while BAwas added into PVA seed latex and initiated, PVA-PBA core-shell latex could not be obtained. This is attributed to the fact that PVAis more hydrophilic than PBA. By putting drops of water on the surface of the latex films prepared from above latexes at 40℃, water-resistance of the films was experimentally measured by reading "turbidity time" of the transparent films. Results showed that PVA films had a much shorter "turbidity time" than PBAdue to its larger hydrophilicity. It is observed that water-resistance of the seeded latex film of PBA-PVA (PBA as seed) was very similar to that of PVA, and that of PVA-PBA(PVA as seed) was significantly different from those of PVA and PBA. It is concluded that particle morphology was unchanged during film formation under the present experimental conditions.
    The Influence of Prepolymerization with Ti-Mg Supported Catalyst on the Gas-phase Polymerization of Ethylene and the Morphology of the PE Particles
    ZHANG Qi-Xing, WU Qing, OUYANG Wei, LU Ze-Jian, WANG Hai-Hua
    1995, 16(3):  481-485. 
    Asbtract ( )   PDF (372KB) ( )  
    Related Articles | Metrics
    The gas-phase polymerization of ethylene with prepolymerized Ti-Mg supported catalyst was studied. The results showed that catalytic activity and bulk density of the prod uct particles increased and the size distributions of the product particles narrowed with the using of prepolymerization method. The morphology of catalyst particles, prepolymer and the polymerization product particles were studied by SEM and image analysis. From these investigation, it was found that the prepolymerization makes catalyst particles puff with fis sure. The particles of prepolymer and polymerization product are composed of bound ag glomerates of fine secondary polymer globules, while the secondary polymer globules consist of smaller primary particles. The average values of diameters (DAV) of catalyst particles,prepolymer and the product particles by image analysis are 33um, 168 um and 263 um, re-spectively, and the ratios of the large axis to small axis(D/d) are 1. 524, 1. 540 and 1. 514,respectively.
    Studies on Morphology of Solution-Cast Films of iPP/aPP Blends
    CHEN Ye, YANG De-Cai
    1995, 16(3):  486-488. 
    Asbtract ( )   PDF (308KB) ( )  
    Related Articles | Metrics
    Morphologies of solution-cast films of iPP/aPPblends have been studied by means of electron microscopy and X-ray scattering techniques. Microscopic observation showed that solution-cast film of iPPconsists of two kinds of structural regions, cross-hatched and lath liked structures. The addition of small amount of aPP (≤300%) into iPPdid not change iPP' s characteristic crystallization behavior. It is noticed that when the content of aPPin its blend was over 80%, iPPformed a very loosely woven-like network composed of very long lameilae with wide-angle lamellar branchings. The X-ray data showed that aPPdid not cocrystallize with iPP.
    TEM Studies on Deformation Mechanisms of PS/LDPE Blends
    XU Shi-Ai, JIANG Ming, SHEN Jing-Shu
    1995, 16(3):  489-490. 
    Asbtract ( )   PDF (143KB) ( )  
    Related Articles | Metrics
    Based on the TEM observations of the morphologies of the blends under small stretching process, this communication reports the results for the toughness and deformation mechanisms of two typical blends in which the tough component LDPE is minor(LDPE/PS=20/80) and major(LDPE/PS=80/20) constituents respectively. It is found that multi-craze is the main toughness and deformation mechanism when LDPE is the dispersed phase, while microbands caused by shear-yielding becomes major one while LDPE is continuous phase.
    Interaction Parameters of the PET/PC and PET/Phenoxy Resin Blends
    ZHANG Rui-Yun, LUO Xiao-Lie, MA De-Zhu, FAN Feng-Qiu
    1995, 16(3):  491-493. 
    Asbtract ( )   PDF (313KB) ( )  
    Related Articles | Metrics
    In the present work. the miscibility of a series of etliylene terephthalate(ET)caprolactone(CL) random copolyesters (TCL) having different ETcontents blend with polycaprolactone (PCL), polycarbonate(PC) and phenoxy resin (PH) was examined by DSC, and the miscibility limits specified by the ETcontent m TCLwere founcl in these blends. Based on the experimental miscibility in these blends and the mean field binary interaction model.the interaction parameters of the PET/PC and PET/PH blends were obtained.
Special Issues
More...
Download
More...
Links
More...