924 resultados para Chinese studies (Sinology)


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Plussian blue(PB)/Pt modified electrode Tvas studied in the CdCl2 electrolyte solution by cyclic voltammetry and in situ FTIR spectroelectrochemistry. It was found that Cadmium ion was capable of substituting the high-spin iron of PB in an electrochemically induced substitution reaction and hexacyanoferrate cadmium (CdHCF) can be formed in the PB film. But PB and CdHCF in mixture film showed their own electrochemistry properties without serious effect on each other. The mechanism of substitution reaction has been given in detail.

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Using electrospray ionization (ESI) and tandem mass spectrometry techniques, the protonic positions in protonated molecular ions of some narcotic drugs were studied, The data of ESI/MSn experiments of morphine and deuterium-loaded morphine were first discussed. The protonic position was considered to locate on oxygen atom of cyclic ether in morphine molecular, Compared with the same and different: ions among morphine, codeine, acetylcodeine and dihydrocodeine, the protonic positions in protonated molecular ions of these compounds were further determined. The fragmentation mechanism of morphine in ESI/MSn: experiments was also repored in the paper, and there were similar dehydrolysis mechanism in gas phase or in liquid phase for morphine.

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Studies on the bounding character of rare earth ions with borine serum albumin(BSA) are significant for understanding the state of rare earth ions in body and their effects on the structure and function of protein. The fluorescence spectrum and pH potentiometry showed consistent results of apparent complexion constant of Tb-2 . BSA. The equilibrium dialysis showed that there are two specific binding sites and more than six non-specific binding sites of RE ions onto BSA molecule with the conditional stable constants lg K-1 = 5. 157 and lgK(2) = 3. 435. Na-23 NMR studies revealed that the BSA peptide chain bound to RE ions was expanded and the mobility of its molecular backbone was increased.

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The morphology and structure of the syndiotactic polystyrene (sPS)/atactic polystyrene (aPS) blends with various compositions have been studied by means of DSC, optical microscopy, SAXS, and WAXD. The results show that aPS is miscible with amorphous region of sPS. There is no macroscopic evidence that aPS forms separated domains in the blends. The decrease in crystallinity of sPS in the blends implies segregation of the aPS to the interfibrillar regions of the spherulites of sPS. The constancy of interlamellar distance and melting points indicates that the fibrillar structural units of sPS is unchanged on addition of aPS to sPS, and the unchanging parameters of the sPS unit cells mean that aPS does not enter the unit cells of sPS.

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In this paper, a series of Sr1-xLaxNiAl11O19 catalysts were synthesized and their chemical and physical properties were investigated by XRD, UV-DRS, H-2-O-2 titration, TPR and Py-IR techniques. The experimental results show that the Sr1-xLaxNiAl11O19 catalysts have a magnetoplumbite structure and Ni ion is shared between tetrahedral and octahedral sites of the spinel blocks, and the amount of nickel ions in the tetrahedral environment increases with the increase of x value in Sr1-xLaxNiAl11O19. The TPR study revealed that the reducibility of the series of the catalysts depends strongly on the substitution value x, that is, a low temperature peak appears for samples without substitution, in case of samples with x = 1 high temperature peak appears, and for samples with 0

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Stable gadolinium complexes, such as Gd(DTPA) and Gd(DOTA), are usually used as the contrast agents for magnetic resonance imaging(MRI). Reported here are the enhanced relaxation properties of a novel gadolinium complex, diethylene-triaminopentaacetate Lis (isoniazid) [Gd(DTPA-BIN)], in aqueous and in human serum albumin(HSA) solution, which indicates that (1) two Gd(DTPA-BIN) can integrate non-covalently with one HSA with an equilibrium constant of 0. 02 mmol(-2) . L-2 ; (2) the relaxivities are 3. 28 and 4. 92 mmol(-1) . L . s(-1) for the free Gd(DTPA-BIN) and the [Gd(DTPA-BIN)](2), HSA conjugator, respectively; (3) the rotational correlation time of protein conjugator is notably higher than that of the free complex, The above results may imply that Gd(DTPA-BIN) has a higher tissue selectivity than that of its parent Gd(DTPA).

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A new side chain liquid crystalline poly[4-(methacryloxy)hexanoloxy-4'-benzyloxy biphenyl] was synthesized. The phase behavior of the monomer and homopolymer was studied. The monomer shows a smectic B phase, while the homopolymer shows a nematic phase. The nonmesogenic nonlinear optical group was introduced to synthesize a series of side chain liquid crystalline copolymers which also show a nematic phase. Owing to the liquid crystallinity of the copolymer has been the orientational stability improved, down the relax of the orientation slowed and the nonlinear optical properties enhanced.

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A new series of liquid crystals of bis[4-(p-phenoxy)-phenylbenozoate] alkyldicarboxylate which contain two rigid groups connected by a flexible spacer was synthesized. These liquid crystals show nematic phase and were found to show odd-even effect in isotropization temperature and entropy change.

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Molecular connectivity index and comparative molecular field analysis (CoMFA) have been applied to the studies of the correlation of the derivatives of benzamide and their antiallergic activities. The results achieved by using CoMFA based on 3D factors are much better than that obtained by using multiple regression analysis based on majorly 2D structural information. The CoMFA results show that the dominant factor which affects activity is steric, whereas electrostatic effect only plays an unimportant role.

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The positive- and negative-ion electrospray ionization mass spectra of beta-cyclodextrin-amino acids complexes in NH4Ac buffer have been reported in this paper. Compared with positive-ion ESI mass spectra of beta-cyclodextrin-amino acids complexes under the same condition, negative-ion mass spectra obtained for inclusion complexes of beta-cyclodextrin (CD) with tyrosine, phenylalanine and tryptophan, respectively, were completely dominated by deprotonated complex ions and [CD-H](-) ion which is the only daughter ion in collision-induced dissociation (CID) experiment of deprotonated complexes, The results indicated that the charged position for protonated and deprotonated complexes is different from each other. In addition, two complex ions for the same complex have similarly relative dissociation energies, which are higher than that of [CD+NH4](+), indicating that complexes observed in gasphase are not electrostatic adducts at all but complexes formed by hydrogen bonds.

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A novel complex - palladium-coordinated ate-type liquid crystalline dendrimer was synthesized by a divergent approach, The product showed liquid crystalline properties from 115 degrees C to 187 degrees C, and it belonged to dinuclear species, containing two palladium centers linked by two bridging Cl, each palladium atom completes its coordinations with N atom and a sigma bond to an ortho-carbon in the phenyl ring. The microanalytical values obtained for the product are in agreement with those of compound containing ligand, palladium:and chlorine in a molar ratio of 1 : 1 : 1 and 12 palladium atoms for every scaffold.

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A liquid crystalline carbosilane dendrimer with Sc* phase has been synthesized in successive steps, resulting in the formation of defined, unimolecular compound. Twelve biphenyl mesogenic units were attached on its periphery and it has a three dimentional, treelike starburst structure. Its phase behavior was K95S(c)*103Ch118I. Compared.with its biphenyl mesogenic unit , 4-(2'-methylbutyl)-4'-(omega-hydroxyhexyl) azobenzene , which was melted at 128 degrees C and is not a liquid crystal, it is a good liquid crystal material with Sc* phase.

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The membranes of polyvinylidene fluoride, which were synthesized by our laboratory, were used to study the transfer and extraction performances of Nd(III) and Sm(III) with the extraction system of HEH/EHP-kerosene. The results show that the membrane material was suitable to the study on membrane extraction, and could offer a good transfer performance in the membrane construction parameters selected, The extraction reaction in the membrane module was the same as that in liquid-liquid process, HEH/EHP ammoniated for increasing the mass transfer coefficient was almost the same with increasing the concentration of HEH/EHP, and H+ was still transferred first at higher pH range of feed solution when HEH/EHP was ammoniated, The controlling model of the membrane extraction process was the diffusion model accompanied by interfacial reaction, The controlling function of interfacial reaction would increase gradually with the increasing of the membrane pore size. The mass transfer coefficient increased when extraction and stripping were carried out simultaneously.

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The mixed oxides, including YBa2Cu3O7, LaBa2Cu3O7, LaBaCu2O5, La2BaCu3O7, La4BaCu5O12 with perovskite structure, were prepared. The catalysts were characterized by means of chemical analysis, XRD, TPD and TPR method. It was found that they were the active catalysts for the NO decomposition and NO reduction by CO. The existance of Cu3+ is an important factor to give the catalysts a high activity for the NO reduction by CO.