Loading...
CJCU

Table of Content

    24 February 1998, Volume 19 Issue 2
    Previous Issue    Next Issue
    Articles
    Hydrothermal Synthesis of a Giant Magnetoresistance Material La0.5Ba0.5MnO3 Under Mild Conditions
    WANG Dan, YU Ran-Bo, FENG Shou-Hua, ZHENG Wen-Jun, PANG Guang-Sheng, ZHAO Hui
    1998, 19(2):  165-168. 
    Asbtract ( )   PDF (1430KB) ( )  
    Related Articles | Metrics
    Agiant magnetoresistance material La0.5Ba0.5MnO3 was prepared by hydrothermal method at 240 ℃ for 24 hours. The product was characterized by X-ray powder diffraction, differential thermal analysis-thermogravimetric analysis, chemical analysis, and iodometry. The compound crystallizes in a cubic system with cell parameters a =0.3913 nm and V =0.05990 nm3. The average valence state of manganese was 3.5, and the magnetoresistance (MR) is about 29% at 1 T.
    Bidisperse Pore Diffusivity of Eu3+ Ion in Porous Ion Exchange Resins
    LING Da-Ren, LIU Yu-Cheng, ZHENG Zu-Ying
    1998, 19(2):  169-173. 
    Asbtract ( )   PDF (230KB) ( )  
    Related Articles | Metrics
    In this paper the self diffusion of rare earth ion(Eu3+ ) in porous ion exchange resins D72 and D751 was studied by isotope exchange reaction. Applying Kataoka's bidisperse pore model, the intraparticle effective diffusivities De were resolved into a solid diffusivity Dg and a macropore diffusivity Dp. The results express that Kataoka's equations can illustrate the kinetic process of porous ion exchange resins. The experiments show that De, Dp and Dg all increase with the increase of reaction temperature and the self-diffusion activation energy of Eu3+ ion under the experimental conditions was calculated; the response Dp and Dg to temperature of D72 resin is more sensitive than that of D751; De, Dp and Dg of D751 resin is smaller than that of D72 resin; the diffusivity of Eu3+ ion in solution is larger than Dp, which leads to the conclusion that the diffusion of ion in the pore of ion exchange resin can not completely be equal to that in solution.
    Synthesis,Characterization and Oxygenation Property of Bisbenzoin-semitriethylenetetraamine and Its Bisnucleus Transition Metal Complexes
    ZHONG Chao-Fan, DENG Jian-Cheng, TONG Jue, YAO Xiao-Hong, ZHU Wen-Song
    1998, 19(2):  174-178. 
    Asbtract ( )   PDF (223KB) ( )  
    Related Articles | Metrics
    Bis-benzoin-semitriethylenetetraamine was synthesized in yield 89% via the reaction of benzoin with triethylenetetraamine by refluxing in ethanol(95%), and complexes of Co(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ), coordinated by it and oxalic acid were also synthesized by metal salts, bis-benzoin semitriethylenetetraamine and H2C2O4 in CH2Cl2 solvent. They were all characterized by elementary analysis, IR, MS, molar conductivity and thermal analysis. The saturated oxygen uptake of the complexes in DMFsolvent at 0 ℃ obtained by manometric uptake measurements is two mmol O2 per mmol complex.
    Synthesis,Structure and Magnetism of [Nd(ONO2)6][Cu(Im)(phen)2]2(OH)·4H2O
    NIU Shu-Yun, YANG Zhong-Zhi, YANG Qing-Chuan, YANG Bing, CAO Jin-Quan, YANG Guang-Di
    1998, 19(2):  179-183. 
    Asbtract ( )   PDF (244KB) ( )  
    Related Articles | Metrics
    The crystal of [Nd(ONO2)6][Cu(Im)(phen)2]2(OH)·4H2O was synthesized and its structure of its single crystal was determined by X-ray diffraction. The crystal is triclinic system, space group P1 with a = 1.0126(2) nm, b = 1.1792(2) nm, c = 1.3985 nm, α=111.32(3)°, β=93.17(3)°, γ=90.33(3), V = 1.5526(5) nm3, Z=1, Dc=1.700 g/cm3, F (000) =801, R =0.043, Rw=0.070. UV-Vis-NIR, IR and magnetic susceptibility were determined and the related properties of the complex were discussed. It is found that the title complex possesses the behavior of anti-ferromagnetic material at low-temperature.
    A Study of the Effect on the Stability of Axial Complex of meso-Tetra(m-substituted)phenylporphyrin Zinc
    RUAN Wen-Juan, ZHU Zhi-Ang, CHEN Hong-Wei, ZHANG Zhi-Hui, SHAO Ying, CHEN Yun-Ti
    1998, 19(2):  184-189. 
    Asbtract ( )   PDF (2259KB) ( )  
    Related Articles | Metrics
    A thermodynamic study is reported for the coordination reaction of meso-tetra(m-substituted)phenylporphyrin zinc [ZnT(m-X)PP, X=NO2, Cl, OCH3, H, CH3] with four substituted imidazoles and three new metal imidazolate complexs of unsymmetrical tetradentate Schiff bases in CH2Cl2 solvent by spectrophotometer technique. The equilibrium constant K was determined by Rose Drago's method. The effect of temperature, axial ligands, the substitutents of porphyrin on the stability of complex were studied. It was found that Hammett linear and isoequilibrium relationships exist in the system. The values β and ρ∞ obtained by different approaches in the system are in agreement with each other.
    Synthesis and Characterization of Novel Peroxopolyoxometalates,[NBu4]3[M(O2)W5O18](M=Nb,Ta)
    YU Hong-Kun, HUANG Zu-En, CAI Rui-Fang, DAI Wei-Lin
    1998, 19(2):  190-192. 
    Asbtract ( )   PDF (158KB) ( )  
    Related Articles | Metrics
    The title compounds have been prepared by dissolving sodium niobate(or sodium tantalate) and sodium tungstate in 30% hydrogen peroxide solution at -5 ℃ and adjusting pH=1 with hydrochloric acid. The results of elementary analysis, TG-DTG, IR, UV and XPS indicate that the title compounds have the hexametaiate type structure, and the O22- group is coordinated with niobium or tantalum.
    The Application of Spline Wavelet and Fourier Transformation in Analytical Chemistry
    BAO Lun-Jun, MO Jin-Yuan, TANG Zu-Ying
    1998, 19(2):  193-197. 
    Asbtract ( )   PDF (241KB) ( )  
    Related Articles | Metrics
    The wavelet analysis is an effective technique for processing data. Because the system quantization error of digital filter, algorithm and other elements easily create the offset of peak position especially in processing gradual change signal. In this paper, we have discussed the advantages and disadvantages of spline wavelet and Fourier transformation methods, designed the combined algorithm of these two methods, optimized the parameters and used this method successfully to process signal with high noise, even whose S/N is 0.1. Experimental data were processed by the proposed method and satisfactory results were obtained.
    Preparation of pH-Sensitive Phase Separating Polymers and Its Application in Immunoassay
    ZHOU Ping, DENG Yan-Zhuo, ZENG Yun'e
    1998, 19(2):  198-200. 
    Asbtract ( )   PDF (152KB) ( )  
    Related Articles | Metrics
    The methylmethacrylate-acrylic acid-maleic anhydrate copolymer(MAM) and methacrylic acid-acrylamide-N-acryloxysuccinimide copolymer(MAN) were prepared. These copolymers were conjugated with monoclonal antibody separately and utilized in a novel separation method for enzyme immunoassay. The polymer precipitated out of water below a critical pH, enabling the polymer-bound immune complex to be separated from the solution. However, the MAM-antibody can show phase separation properties in urine, but can not precipitate in serum. The MAN-antibody showed the insoluble form below pH 3.5 and soluble form above pH4.0. It has been demonstrated to be applicable to determination of antigen by determining HBsAg in serum. Forty-five samples were assayed, and there was a good correlation between the results by this method and ELISA.
    Behavior of Silver Cluster on Laser Desorption/Ionization Time-of-flight Mass Spectrometry
    FANG Shi-Ping, HAO Chun-Yan, LIU Zhi-Qiang, LIU Shu-Ying
    1998, 19(2):  201-203. 
    Asbtract ( )   PDF (271KB) ( )  
    Related Articles | Metrics
    Asuccessful analysis of silver was reported utilizing laser desorption/ionization time of flight mass spectrometry(LDI/TOF-MS) in this paper. The silver cluster ions Agn+ and Agn O+(n =2～5) were formed during laser desorption/ionization. In the presence of I-, K+ and Na+, the peaks corresponding to the cluster ions [AgnIn-1]+(n =2～6) and the adduct ions [AgI]+, [AgI]Na+ and [AgI]K+ were observed in the positive ion spectrum; the peaks corresponding to [Agn In+1]- (n =1～3) were found in the negative ion spectrum, all of which accompanied by sliver isotope distribution. The formation of silver cluster ions was accomplished through two-stage reaction: the first step was the generation of clusters, which was followed by the processes of photoionization and ion/molecule reaction.
    Thin-layer Spectrofluoroelectrochemical Studies of Riboflavin
    ZHOU Tao-Yu, YU Jun-Sheng
    1998, 19(2):  204-206. 
    Asbtract ( )   PDF (394KB) ( )  
    Related Articles | Metrics
    A new designed thin layer electrochemical cell can be used in conjunction with a spectrofluorometer to monitor the changes in the fluorescence properties of riboflavin as a function of applied solution potential Experimental values of E0' and n determined for riboflavin in the BR-KCl solution are -0.399 V ( vs. Ag/AgCl) and 1.95, respectively
    A Study of Synergistic Effects on Special Mixed Stationary Phases in GC
    YUAN Li-Ming, FU Ruo-Nong, DAI Rong-Ji, YANG Zhen-Qing, XU Shi-Xue, CHEN Xue-Xian, XU Qi-Heng
    1998, 19(2):  207-209. 
    Asbtract ( )   PDF (158KB) ( )  
    Related Articles | Metrics
    In the separations of ethylbenzene/benzene, o-xylene/benzene, styrene/benzene, styrene/toluene and styrene/ethylbenzene on the mixed stationary phases composed of perpentylated β-CD and AgNO3, perpentylated β-CD and TlNO3, Benton-34 and AgNO3 in GC, the positive synergistic effects or negative synergistic effects were discoveried. This phenomenon was investigated carefully. The effects of separation temperature, and how the stationary phases to be mixed were accomplished.
    Copper(Ⅱ)Sensitive Electrode Based on Nonstoichiometric Compound TiO2-σ
    XIAO Dan, LI Jun, LIN Hui-Gai, YUAN Hong-Yan, WANG Ke-Min, YU Ru-Qin
    1998, 19(2):  210-212. 
    Asbtract ( )   PDF (452KB) ( )  
    Related Articles | Metrics
    Anew potentiometric sensor for copper(Ⅱ) based on a titanium matrix is proposed. The sensor shows a Nernst response toward copper(Ⅱ) which seems to originate from the nonstoichiometric compound TiO2-σ layer covering on the electrode surface according to the results of XPS spectra of the electrode surface and a.c. impedance of the electrochemical system. The sensor owned a linear range from 10-5～10-2 mol/L with a detection limit of 5×10-6 mol/L in 0.1 mol/L citric acid-sodium dihydrogen citrate buffer solution of pH 2.2 The standard deviations determined by alternatively immersing the electrode in 1.0×10-4 and 1.0×10-3 mol/L levels six times are 1.7 mVand 1.4 mV, respectively. The e.m.f. drift in 10-3 mol/L copper(Ⅱ) solution is less than 2mV within two hours. The sensor has an excellent selectivity for copper(Ⅱ) with respect to many common divalent cations.
    Electrocatalytic Oxidation of Plant Hormone 6-Benzyl Adenine by Copper Ion
    WANG Hong, HU Sheng-Shui, ZHOU Xing-Yao
    1998, 19(2):  213-215. 
    Asbtract ( )   PDF (160KB) ( )  
    Related Articles | Metrics
    This paper deals with electrocatalytic oxidation of plant hormone 6-benzyl adenine by Cu2+ in BR buffer on GC. It was found that Cu2+ was reduced and generated Cu+, which reacted with 6-benzyl adenine. The 6-benzyl adenine-Cu+ compound reoxidated of Cu+ to Cu2+ and gave an oxidation peak at 0.46 V( vs. SCE). This peak current shows a linear relationship with the concentration of 6-benzyl adenine in the range of 1×10-5～9×10-5 mol/L. When accumulation time was 8 min, a detection limit of 2×10-7 mol/L was obtained.
    Studies on Seperation Behaviour of Six Benzene Derivatives by Reverse-phase Capillary Electrochromatography
    GUAN Yan-Hua, WEI Wei, WANG Ru-Ji, LUO Guo-An
    1998, 19(2):  216-218. 
    Asbtract ( )   PDF (174KB) ( )  
    Related Articles | Metrics
    Amixture of six benzene derivatives, i.e. aniline, acetophenone, o-nitrotoluene, toluene, o-xylene, o-chlorotoluene was seperated in less than 14 minutes on a 50 μm(i.d.)×37 cm/30 cm capillaries column packed with 3 μm ODS-silica in the CH3CN-H2O-Tris(HCl) buffer by reversed-phase capillary electrochromatography(RP-CEC). The effects of acetonitrile concentration(φ =50%～80%), electrolyte concentration(1～20 mmol/L) and pH(3～10) on the electroosmotic flow(EOF), and the retention behavior of analytes was investigated. A study of the reproducibility of the packed column was performed. The relative standard deviations for the retention time and capacity factor were lower than 1% and 1.5%.
    A Research for the Catalysis Kinetics Analysis with Chemical Relaxation Method
    HUANG Zheng-Hua, LIN Zhi-Xin, CAI Ru-Xiu, ZHANG Ke
    1998, 19(2):  219-221. 
    Asbtract ( )   PDF (164KB) ( )  
    Related Articles | Metrics
    A chemical relaxation kinetics analysis(CRKA) method has been proposed for the first time. The basic theory has been proved systematically and was applied to determine trace copper. Stopped-flow equipment was used for analyzing the system of Fe(Ⅲ)-S2O32- catalyzed by Cu(Ⅱ). We studied the influence of pH value, medium and reagent on relaxation parameter (1/τ) and obtained the linear relation of 1/τ and concentration. The analytical results of synthetic samples show that the CRKA method has an obvious advantage.
    Design,Synthesis and Biological Activity of Novel Hebicides Targeted ALS(Ⅵ)——The Electronic Structure of Herbicidal Pyrimidinyl(thio)ether Compounds and the Molecular Design of Novel Herbicides
    YANG Guang-Fu, LIU Hua-Yin, LU Rong-Jian, YANG Hua-Zheng
    1998, 19(2):  222-227. 
    Asbtract ( )   PDF (1471KB) ( )  
    Related Articles | Metrics
    Pyrimidinyl(thio)ether compounds are a kind of novel class of ALSinhibitors. In view of quantum pharmacology, their electronic structure was firstly investigated by means of quantum chemical calculations. The results revealed that there is a large electronegative region around the pyrimidinyl moiety in the highly active molecule. The herbicidal activity is related to the potency of electric charge translocation of the heterocyclic regions. On the basis of the above results, a novel kind of herbicides was designed and synthesized and was found to exhibit a good herbicidal activity with pIC50 over 7.
    Synthesis and Herbicidal Activity of 3-Arylsulfonyloxy (substituted) isothiazoles
    YANG Xiao-Ping, LI Zheng-Ming, WANG Ling-Xiu, LI Yong-Hong
    1998, 19(2):  228-231. 
    Asbtract ( )   PDF (193KB) ( )  
    Related Articles | Metrics
    To look for novel compounds with biological activity, 3-arylsulfonyloxy(substituted) isothiazoles were synthesized by the condensation of 3-hydroxy(substituted) isothiazoles with arylsulfonylchlorides in the presence of base. The strctures of target compounds were confirmed by elemental analysis, 1H NMR, IR, MS. Also, the single crystal structures of compounds 3c and 4b were determined. All the facts ascertained that the sulfonylization position was oxygen atom of isothiazole heterocycle. The herbicidal activities of title compounds were determined and the result showed that it was possible that they were ALS inhibitors.
    Studies on the Synthesis and Bioactivities of Substituted Dihydropyrazole Derivatives
    LIU Tian-Lin, YU Sheng-Liang, YU Ai-Ming
    1998, 19(2):  232-236. 
    Asbtract ( )   PDF (628KB) ( )  
    Related Articles | Metrics
    A novel and convenient synthetic method for 1-phenyl-3-substituted phenyl-4-triazolyldihy-dropyrazoles(1a-1b) and 3-substituted phenyl-4-triazolyldihydropyrazole (7) from α-triazolyl-β-alkoxyacetophenone 4 was described. The reaction condition was studied and optimized. 1,3,4,5-Multi substituted dihydropyrazole 1c-1h were prepared through the general cyclization of α, β-unsaturated ketone with phenylhydrazine and their structures were confirmed by 1H NMR, MS and elemental analysis. Furthermore, 3,5-substituted dihydropyrazole 6(or 7) reacted with methyl(or ethyl) chloroformate and potassium thiocyanate to afford 1,3,5-(or 4-)substituted dihydropyrazole 2a-2l. The results of preliminary bioassay presented that almost all compounds showed fungicidal, herbicidal and plant growth regulatory activities.
    Low-valent Titanium Induced Reductive Cyclization of (3-Oxo-1,3-diaryl)propylpropanedinitrile
    SHI Da-Qing, TU Shu-Jiang, ZHOU Long-Hu, FENG You-Jian, DAI Gui-Yuan
    1998, 19(2):  237-242. 
    Asbtract ( )   PDF (270KB) ( )  
    Related Articles | Metrics
    This paper reports the reactions of low-valent titanium reagent(TiCl4-Zn system) with (3-oxo-1,3-diaryl) propylpropanedinitrile. It is found that the low-valent titanium can promote a novel cyclization of (3-oxo-1,3-diaryl)propylpropanedinitrile to give 2-cyano-3,5-diary-1-aminocyclopentene, trans and cis 2-amino-3-cyano-1,4-diary-2-cyclopentene-1-ol. The latter's configurations are determinated by X-ray diffraction analysis.The crystal of compound 3c is triclinic with space group P1, a =1.0389(4) nm, b =1.2292(4) nm, c = 0.8027(3) nm, 7 α = 93.29(3)°, r =113.32(3)°, V =0.9362(6) nm3, Z =2, Dc=1.1939 g/cm3, μ =0.77 cm-1, F (000)= 360, and find R =0.067 and Rw=0.057 for 1308 reflections ( I >3 σ ( I )). The crystal of compound 4a is orthorhombic with space group Pbcn, a = 1.3370(5) nm, b = 1.0481(5) nm, c =2.3350(6) nm, V =3.272(3) nm3, Z =8, Dc= 1.262 g/cm3, μ = 2.36 cm-1, F (000)=1296, and find R =0.043 and Rw=0.049 for 1426 reflections ( I >3 σ ( I )). A possible reaction mechanism is proposed in this paper.
    Studies on the Synthesis and Bioactivity of 5,5'-Val2-AMD and 2,2'-Phe2-AMD
    NI Jing-Man, WANG Rui, JIA Zheng-Ping, PAN Xin-Fu, HU Xiao-Yu
    1998, 19(2):  243-245. 
    Asbtract ( )   PDF (1124KB) ( )  
    Related Articles | Metrics
    A ctinomycin D(AMD) contains a planar phenorazone ring as well as two cyclic depsipeptides and is best known for its effectiveness as an inhibitor of transcription. It has been used clinically for treating Wilm's tumor, gestational chriocarcinoma. Although it possesses valuable biological activities its high cytotoxity and inactivities toward some tumors have prompted the search for modified AMD. On the basis of the result of AMD-DNA binding model proposed by Takusagawa, we designed and synthesized 5,5'-Val2-AMD and 2,2'-Phe2AMD. The title compounds were synthesized from 3 in 13 steps with overall yield of 27%, 17%, respectively. The structures were identified with 1H NMR, 2D NMR, MS and HRMS. The biological activities of two analogs were carried out in comparison with those of AMD. The order of antitumor activity was 2,2'-Phe2-AMD>AMD>5,5'-Val2-AMD.
    The Synthesis and Time-resolved Spectra of Indolinospironaphthopyrans
    WU Xin-Yan, WU Cheng-Tai, WANG Wen-Feng, YAO Si-De
    1998, 19(2):  246-248. 
    Asbtract ( )   PDF (312KB) ( )  
    Related Articles | Metrics
    Three indolinospironaphthopyrans: 1',3'-dihydro 1',3',3'-trimethyl spiro [2H-indole-2,3-(3H)naphtho [2,1-b] pyran], 1',3'-dihydro-3',3'-dimethyl-1-(2-hydroxyethyl)-spiro [2H-indole-2,3-(3H)naphtho [2,1-b] pyran], 1',3'-dihydro-3',3'-dimethyl-1-(5-iodo-3-oxypentyl)-spiro [2H-indole-2,3-(3H)naphtho [2,1-b]pyran were synthesized, and their photochromic reactions were studied using nanosecond laser photolysis technique. Photolysis of these compounds in acetonitrile and in tetrahydrofuran leads to the formation of the long-lived photomerocyanine(PMC) as the predominant photoproduct.The formation of the PMC occurs owing to C-O bond opening, mainly directly from the excited single state of the spiropyran(SP). From the absorption bands, it has been speculated that the substituents of the nitrogen atom of the indole ring influence the structural characteristics of the PMC mainly through steric hindrance effects. A potential energy surface model is established to explain the results.
    Studies on the Chemical Constituent of the Alga Caloglossa Leprieurii
    XU Xiao-Hua, SU Jing-Yu, ZENG Long-Mei, WANG Ming-Yan
    1998, 19(2):  249-251. 
    Asbtract ( )   PDF (147KB) ( )  
    Related Articles | Metrics
    Five secondary metabolites have been isolated and identified from the alga(caloglossa leprieurii), collected from the Xisha Islands in South China Sea. This alga is a Chinese traditional drug having been used as anthelmintic. Their structures were determined as α-glyceryl-α-mannoside-4-ammonium salt 1, di(amino-carboxy-ethylene)sulfone 2, caulorpin 3, 4, cholestol 5 by spectral analysis. The structures of 1 and 2 are first reported.
    Effects of Electrolytes and Cationic Surfactant on Colloidal Properties of MMH/Mt System
    SUN De-Jun, HOU Wan-Guo, HAN Shu-Hua, SONG Shu-E, ZHANG Chun-Guang
    1998, 19(2):  252-256. 
    Asbtract ( )   PDF (208KB) ( )  
    Related Articles | Metrics
    The effects of electrolytes (NaCl, Na2SO4 and MgCl2) and cationic surfactant (cetyltrimethylammonium bromide) on colloidal properties of mixed metal hydroxide (MMH)/montmorillonite (Mt) suspension were studied through measurements of electrophoretic mobilities, rheology and pH. The results show that all the electrolytes and surfactant studied in this work decreased Bingham yield point (YP) of MMH/Mt system, but exerted different effects on fluid loss (FL) and pHof MMH/Mt system. The results are interpreted as means that the cationic ions of electrolytes mainly displace the charge-balancing ions of Mt particles, such as H+ and Na+, so enhance their aggregation, leading to the decrease of pH and the increase of FL, but the anionic ions of these electrolytes mainly displace the charge-balancing ions of MMH particles, such as OH- and Cl-, so weaken the aggregation effects of MMH on Mt particles, therefore, cause the increase of pH and the decrease of FL. In another word, the overall effects of electrolytes on MMH/Mt system depend on the relative ability of anionic and cationic ions to exert the opposite effects on FL and pH. As for cetyltrimethylammonium bromide (CTAB), the adsorption of CTAB on Mt particles does not only displace H+ and cause the aggregation of Mt particles but also reverses their wetting ability, therefore, CTABdecrease FL and YP of MMH/Mt system to a larger extent than inorganic electrolytes although it can only decrease pH slightly.
    Studies on Excitation Energy Transfer of Completely Synthesized Bilayer Membrane Containing Biphenyl Moiety
    LI Guo-Wen, LIANG Ying-Qiu, WU Li-Xin, SHI Tong-Shun, SHEN Jia-Cong
    1998, 19(2):  257-260. 
    Asbtract ( )   PDF (198KB) ( )  
    Related Articles | Metrics
    Intermolecular excitation energy transfer has been investigated in the binary mixture system mediated by completely synthesized bilayer membrane containing biphenyl moiety(DBBTAB). The donor, a biphenyl group, was embeded in the interior of the bilayer membrane. The acceptor, fluorescein sodium salt, two negatively charged polar groups, was attracted electrostatically to the positively charged surface of the DBBTAB vesicles. The efficiency of the energy transfer was found to be good. Fluorescein quenched the fluorescence intensity of the biphenyl, which fitted a Stern-Volmer relationship over the concentration ranges of 0～8×10-5 mol/L. The functionallization of the vesicles in the energy transfer was explored, and energy transfer mechanism was discussed too. Furthermore, energy transfer from the fluorescein donor to tetraphenylporphyrin sulfated sodium acceptor, was also observed in the same system. The energy transfer improved light efficiency and extended the spectral region. The experiment results imply that the DBBTAB vesicle is better media for energy transfer in dye laser and good membrane mimic agent.
    Oxidative Coupling of Methane over La-Ba-Sn(Sm,Ce)Catalysts
    PIAO Hong, XU Mei-Ping, BI Ying-Li, ZHEN Kai-Ji
    1998, 19(2):  261-264. 
    Asbtract ( )   PDF (208KB) ( )  
    Related Articles | Metrics
    The catalytic performance of La-Ba-Sn(Sm,Ce) system catalysts was investigated. The results showed that the addition of Sn, Sm and Ce components significantly improved the catalytic activities and C2 selectivities for OCM, Furthermore, low calcination temperature was favorable for the low temperature OCM reaction, and high C2 yields and selectivities were obtained at high calcination temperature and under optimum reaction conditions. In combination with XRD, XPS analysis, it can be concluded that the third components are highly dispersed in the bulk of the catalysts, which is responsible for the OCM.
    Studies on Cellulose-based Magnetic Polyamidoxime Adsorbents——Adsorption Kinetics of Adsorbents for Bromine
    WU Jin-Yuan, YANG Chao-Xiong
    1998, 19(2):  265-269. 
    Asbtract ( )   PDF (287KB) ( )  
    Related Articles | Metrics
    Adsorption kinetics of acidic and alkaline cellulose-based magnetic polyamidoxime adsorbents(AMAO and BMAO) for bromine was investigated. The results show that the adsorption rate is controlled by intra-particle diffusion, however, it is also affected by mass action. Under the experimental conditions, the relationship between the adsorption capacity and the concentration of bromine was found to be confirmed with Freundlich equation and Langmuir adsorption isotherm. The higher super-molar ratio adsorption suggests that the adsor ption is followed by redox reaction, but the occurrence of cycle adsorption is considerable.
    Studies on the Synthesis for γ-FeOOH Ultrafine Powders
    HAN Jin-Yi, LI Chun-Zhong, HU Li-Ming
    1998, 19(2):  270-274. 
    Asbtract ( )   PDF (468KB) ( )  
    Related Articles | Metrics
    FeCl2 as the precursor, γ-FeOOH was prepared and the process conditions such as reaction temperature, reactants' concentration, NaOH dropping style were deeply investigated. Optimum condition was then concluded. The results indicated that during the crystal seeds' synthesis, temperature and reactants' proportion could influence the crystal seeds' morphology. During the growing process, the dispersion of NaOH in the system was depended both on the macro-mixing and micro mixing, especially the micro mixing.
    The Influence of Doping Ca in EuFeO3 on Electronic State of Fe Ion
    LI Li-Ping, LIN Xiao-Min, WEI Quan, REN Xiao-Lin, SU Wen-Hui
    1998, 19(2):  275-279. 
    Asbtract ( )   PDF (237KB) ( )  
    Related Articles | Metrics
    Samples of Fe1-xCax FeO3( x =0.0, 0.2～1.0) were prepared by solid state reaction method. XRD measurements show that compounds for x <0.6 have a perovskite structure. Three magnetic and one doublet species were observed at room temperature in the Mössbauer spectra. One of the three magnetic components corresponds to Fe ions in tetrahedral coordination, and the other to Fe ions in octahedral coordination. The shoulder peak of Fe2p3/2 for the samples with x =0 Orelated to Fe ions in different coordinated state. The Fe ions are all in a trivalent state.
    Quantum Chemical Studies on Acetylthiocholine Hydrolysis Catalyzed by Acetylcholinesterase
    WANG Qin-Mi, JIANG Hua-Liang, CHEN Kai-Xian, GU Jian-De, TANG Yun, CHEN Jian-Zhong, JI Ru-Yun
    1998, 19(2):  280-283. 
    Asbtract ( )   PDF (1250KB) ( )  
    Related Articles | Metrics
    Quantum chemical and molecular mechanical methods were employed to study the acylation in the acetylthiocholine hydrolysis catalyzed by acetylcholinesterase. The molecular and electronic structures of the reactants, transition states(TS), products and intermediates were calculated. The results show that the concerted mechanism of protonation and nucleophilic attack proceeding simultaneously in the course of acylation is reasonable.
    Ab Initio Study on Photolysis of Chlorine Nitrate and Its Isomers(Ⅱ)——Investigation of Reaction Mechanism of ClONO2→ClO+NO2
    LIN Meng-Hai, LIN Lian-Tang, CHIU CHOW Lue-Yung
    1998, 19(2):  284-287. 
    Asbtract ( )   PDF (196KB) ( )  
    Related Articles | Metrics
    The reaction mechanism of photolysis for chlorine nitrate that causes ozone lost in the stratosphere ClONO2→ClO+NO2 has been studied by using ab initio calculation method. Two transition states TS2a and TS2b have been found, but it is difficult to overcome so high energy barrier to get to TS2a, and it is easy to pass TS2b over 4.20～4.35 eV energy barrier from the initial state(conformation (B) or (D)) to the final state. However only 1.20 eV is required to pass TS2b from ClO+NO2 to ClONO2, so reaction path (2) is a reversible reaction.
    Theoretical Prediction of C59O's Structure,Electronic Spectra and NMR Spectra
    REN Ai-Min, FENG Ji-Kang, TIAN Wei-Quan, SUN Xiu-Yun, SUN Chia-Chong
    1998, 19(2):  288-291. 
    Asbtract ( )   PDF (1506KB) ( )  
    Related Articles | Metrics
    The INDO program package are used to optimize the substitute C59O of C60, and the stable structure with Cs symmetry is obtained, which has 32 kinds of atoms, 49 kinds of bonds. On the basis of this structure, the electronic spectra and NMR spectra are calculated and analyzed, then compared with the results of the electronic isomer C602- and C60O.
    Asymmetric Carbonylation of α-(6-Methoxy-2-naphthyl)ethanol by PdCl2-CuCl2-p-Ts-Chiral Phosphine Catalyst Systems
    ZHOU Hong-Ying, HOU Jin-Guo, CHEN Jing, LI Zuo-Wei, FU Hong-Xiang, LU Shi-Jie
    1998, 19(2):  292-294. 
    Asbtract ( )   PDF (255KB) ( )  
    Related Articles | Metrics
    α-(6-Methoxy-2-naphthyl)ethanol was carbonylated to methyl ester of Naproxen by PdCl2-CuCl2-p-Ts-chiral phosphine catalyst systems under the mild reaction conditions. Poor enantioselectivities and moderate regioselectivities have been obtained by using the ligand DDPPIfor PdCl2-CuCl2-p-Ts catalytic reaction. The effects of P/Pd molar ratio, reaction pressure, and the kinds of solvents have been also investigated with the catalyst system. The asymmetric induction up to 42.5 and good chemical yields have been obtained in the carbonylation of α-(6-methoxy-2 naphthyl)ethanol with carbon monooxide and alcohol.
    Studies on Gaseous Phase Polymerization of Ethylene with Highly Active Catalyst(Ⅳ)——The Effects of Zinc Compound on the Properties of Catalysts and Products
    WANG Zhi-Ming, XIAO Wei, ZHANG Qi-Xing, WANG Hai-Hua
    1998, 19(2):  295-299. 
    Asbtract ( )   PDF (265KB) ( )  
    Related Articles | Metrics
    The gaseous phase homopolymerization of ethylene has been studied in the presence of TiCl4, Ti(OBu)4/MgCl2, SiO2, ZnCl2/SiCl4/alcohol/AlR3 highly active catalysts (named Cat# A and Cat# B) which were prepared by different precipitating-reaction procedures. It was found that the catalytic efficiency increased and there was an optimum value respectively in bulk density and mass distribution of polymer with the increase of the amount of ZnCl2 AlEt3 used to treat SiO2. The kinetics curves of gaseous phase etheylene polymerization with two catalysts showed a decline and the decay rate with Cat# A was larger than that with Cat# B. The analysis of the components of the catalysts showed that zinc compound is one of the important compositions of supports, which can notably control the molecular weight of the products. This should be ascribed to the fact that diethyl zinc compound formed in site of the ethylene polymerization system due to the interaction between ZnCl2 and trialkyl aluminnium is liable to induce transfer reaction of PE propagation chains. The particle structures and the properties of the catalysts and the obtained products of PE were characterized by the determination of surface area and SEM, FTIR and DSC. The morphology of the catalysts and products of polymerization by SEM showed that all the particle shapes were nearly spherical. Compared with the matrix PEprepared by MgCl2-supported titanium catalyst, the products prepared with Cat# A and Cat# B have a higher branching degree, lower crystallinity and wider melting peak. The products prepared with Cat# B with melting dual peak(peak temperature 133.0 ℃ and 140.0 ℃) have newly been found.
    Studies on Chitosan-fibroin Blend Membranes(Ⅰ)——Structure of the Blend Membrane and the Improvement of the Water Adsorption and the Mechanical Property of Fibroin
    CHEN Xin, LI Wen-Jun, ZHONG Wei, LU Yu-Hua, YU Tong-Yin
    1998, 19(2):  300-304. 
    Asbtract ( )   PDF (226KB) ( )  
    Related Articles | Metrics
    By means of FTIR, X-ray diffraction, TGA and DSC measurements, the structure of chitosan-fibroin blend membrane has been analyzed. The results showed that there was a strong hydrogen bond interaction between chitosan and fibroin in the blend membrane. Therefore, according to the result of X-ray diffraction as well as the phenomenon that the membrane was transparent and there was no obvious macrophase separation observed by SEM, it could be concluded that the chitosan-fibroin blend membrane was basically compatible. It was also found that the water adsorption property and the mechanical property of fibroin membrane were improved by blending chitosan.
    Study on Oxidation and Electron Transfer in Phosphoryldipeptide Methyl Ester
    CHU Gao-Sheng, YAO Si-De, CHEN Jia-Fu, ZHANG Zhi-Cheng, ZHANG Man-Wei
    1998, 19(2):  305-308. 
    Asbtract ( )   PDF (477KB) ( )  
    Related Articles | Metrics
    The Br2-· induced oxidation and electron transfer in N-(N-phosphorylmethionyl) tryptoyl methyl ester (NDM—TrpOMe) in aqueous solution were investigated using pulse radiolysis technique. The results indicated that the N-phosphoryl methioyl and tryptoyl group were oxidized by Br2-· radicals simultaneously, and intramolecular electron transfer from tryptophan to the three-electron-bonded intermediate containing sulfur occured. Some kinetic parameters were determined and the reactive mechanism was deduced.
    Synthesis and Characterization of New Precursor Polymers of Poly[2-methoxy-5-(4-bromobutoxy)phenylene vinylene]
    YU Ying-Feng, CUI Jun, CHEN Rui, LI Shan-Jun
    1998, 19(2):  309-312. 
    Asbtract ( )   PDF (201KB) ( )  
    Related Articles | Metrics
    Two kinds of novel water soluble polyeletrolyte and organic soluble precursor polymers of poly(phenylene vinylene) with bromine substituted side chain were synthesized from tri-sulfonium salt monomer. The results showed that the sulfonium salt on the butoxy substituted side chain did not take part in the polymerization, thus the organic soluble precursor can be obtained at proper condition. Primarily photo-physics studies showed that the poly(phenylene vinylene) with bromine substituted side chain doped with C60 had good photo-electric properties. The structure of the monomer and the precursor polymers were characterized by IR, UV Vis, 1H NMR, GPC and DSC.
    Influences of Polymerization Temperature on Some Structures and Properties of Poly(vinyl chloride)Resin
    BAO Yong-Zhong, WENG Zhi-Xue, HUANG Zhi-Ming, PAN Zu-Ren
    1998, 19(2):  313-317. 
    Asbtract ( )   PDF (571KB) ( )  
    Related Articles | Metrics
    Poly(vinyl chloride)(PVC) resins were synthesized at different polymerization temperatures( T ) by suspension process. The average molecular weight ( M ), syndiotacticity, crystallinity and glass transition temperature (Tg) of PVCresin were characterized by GPC, 13 C NMR and DSC methods. The results showed that M decreased as T increased, the logarithmic values of M were proportional to the reciprocal of T, the syndiotacticity, crystallinity and Tg increased with decreasing of T, the calculated crystallinity based on the syndiotacticity approached to the experimental value in the case of the value of the minimum sequence length for syndiotactic chain segment contributing to the crystallites was 6.
    Mechanism Studies of Complex Formation Between an Amphiprotic Anion(HBPN)and a Cationic Surfactant(CTAB)
    MA Rong-Jiu, WU Chi
    1998, 19(2):  318-321. 
    Asbtract ( )   PDF (199KB) ( )  
    Related Articles | Metrics
    The interactions between an amphiprotic anion HBPN (highly branched polyester nanoparticle) and a cationic surfactant CTAB (cetyltrimethylammonium bromide) in buffer and HBPN/CTAB complex formation were investigated by dynamic laser light scattering. The results indicated that the core/shell structure HBPN/CTAB complexes were formed by positively charged HBPN and oppositely charged CTAB micelles, which were made from CTAB molecules at first, due to the static electricity interaction in alkaline solution. The complex size can be controlled by solution pHvalue and CTAB concentration.
    Studies on New Type Chelating Resins(Ⅰ)——Synthesis and Sorption Properties of Chelating Resins Having Polythioether Backbone and Primary Amino Group
    LI Wei-Shi, SHEN Zhi-Quan, ZHANG Yi-Feng
    1998, 19(2):  322-325. 
    Asbtract ( )   PDF (1000KB) ( )  
    Related Articles | Metrics
    Four new chelating resins containing polythioether backbone and primary amino group inside chain were synthesized from poly(chloromethyl thiirane) by Gabriel reaction in this paper. The preparation conditions were optimized, and the sorption properties of these resins were thoroughly studied. It was found that these resins possessed high capacities for sorpting noble metal ions, especially for Au(Ⅲ) (5～7 mmol for per gram resin) and Ag+ (7～9 mmol for per gram resin), but weak sorbabilities for non noble metal ions, such as Fe 3+, Cu 2+ and Zn 2+ . They are expected to be used in separations and enrichments of noble metal ions.
    The UV Absorption of Some Photoinitiators in Microemulsion Systems
    RAN Xiao-Yuan, ZHANG Li-Ping, ZENG Zhao-Hua, CHEN Yong-Lie
    1998, 19(2):  326-327. 
    Asbtract ( )   PDF (260KB) ( )  
    Related Articles | Metrics
    The UVabsorption of α-hydroxy-α,α-dimethyl-(p-hydroxyethyloxy)-acetophenone(HMHOAP), α-hydroxy-α,α-dimethyl-acetophenone(HMAP) and α,α-dimethoxy-α-phenyl-acetophenone(DMAP) in different media was investigated. The apparent blue-shift of the peak position in O/W microemulsion compared to that in pure oil phase is an evidence of the location of the photoinitiator at the interfacial area. The locus of photoinitiator in microemulsion and its significance in understanding the initiation mechanism were discussed.
    Deformation Process and Mechanism of HDPE/LDPE Blends
    ZHAO Yong, YANG De-Cai, A. S. Vaughan
    1998, 19(2):  328-329. 
    Asbtract ( )   PDF (313KB) ( )  
    Related Articles | Metrics
    Blends of HDPEin more LDPE, with appropriate heat treatment,produce a dispersion of separate entities of HDPE in a matrix of LDPE.The system offered an especially favourable means of studying the deformation of melt-crystallized lamellae. It has been found that sheaf-like spherulites are transformed under tensile deformation into hourglass shapes i.e. a double cone aligned along the drawing direction with origin in the center of the object. This is a consequence of different modes of deformation according to the relation of an individual lamella to the tensile axis. The work shows that the lamellae have not undergone melting and recrystallization in the deformation process at room temperature.
Special Issues
More...
Download
More...
Links
More...