STUDIES ON DERIVATIVE FLUORIMETRY Ⅳ. DETERMINATION OF TRACE AMOUNT OF TERBIUM THROUGH ITS TERNARY COMPLEX WITH ACETYLACETONE AND EDTA IN THE PRESENCE OF CETYL PYRIDINIUM CHLORIDE

Terbium can form a ternary complex having a ratio of 1:1:1 with acetylacetone and EDTA. By adding cetyl pyridinium chloride into the above system, a marked enhancement of fluorescence intensity is observed and the ternary complex becomes more stable than before. For analytical application, the derivative spectrofluorimetric method has high sensitivity and the effect of foreign ions is very low. The optimum conditions were obtained. The calibration graph is linear over 5～100μg/mL.     

CATALYTIC REDUCTION OF HEMOGLOBIN AT PHENOTHIAZINE COATED SILVER ELECTRODE

ＣＡＴＡＬＹＴＩＣＲＥＤＵＣＴＩＯＮＯＦＨＥＭＯＧＬＯＢＩＮＡＴＰＨＥＮＯＴＨＩＡＺＩＮＥＣＯＡＴＥＤＳＩＬＶＥＲＥＬＥＣＴＲＯＤＥ￥ＧｅｎＸｉＬＩ；ＸｉａｎｇＭｉｎＬＩＡＯ；ＨｕｉＱｕｎＦＡＮＧａｎｄＨｏｎｇＹｕａｎＣＨＥＮ（Ｄｅｐａｒｔｍｅｎｔｏ...     

DIRECT ELECTROCHEMICAL BEHAVIOUR OF CYTOCHROME C AT A BARE GLASSY CARBON ELECTRODE

A reversible electron transfer between horse heart cytochrome c and a bare glassy carbon electrode was found and the dependence of direct electrochemical behaviotw on the electrode surface state was discussed.     

STRUCTURE-PROPERTY RELATIONSHIP OF POLYELECTROLYTES AND ITS APPLICATION IN STABILIZING DRILLING-MUD IN PRESENCE OF SALTS

A new polyelectrolyte (SPU) has been prepared. It can depress the water-loss of drilling-mud much more effective than the commonly used acrylic polyelectrolytes even in 30% NaCl solution. SPU has phenyl group in the backbone with -SO_3~- in the side chain while the acrylic polyelectrolytes have C—C and -COO~- respectively, there exists an intrinsic relationship between the structure of polymer and its tolerance to salts, it has been found: 1) The adsorption amount of polymer on clay is related closely to the flexibility of polymer chain. 2) The salt-tolerance of -SO_3~- is superior to -COO-. 3) Both SPU-mud and HPAN-mud are plastic fluids. The dependence of yield point on salts relates to the molecular weight of polymer and hydration of ionogenic group, which is quite different for SPU-mud and HPAN-mud. 4 ) The extent of raising zeta-potential of base-mud by SPU is greater than by HPAN, but the extent of dropping zeta-potential of SPU-mud by NaCI is smaller than HPAN-mud. According to these results we suppose the salt-tolerance of SPU-mud is attributed mainly to hydration of -SO_3~- and that of HPAN-mud mainly to network structure formed in the drilling-mud.     

A STUDY ON VOLTAMMETRIC BEHAVIOR OF INDIGO CARMINE AND ITS MIXTURE WITH AMARANTH AT MERCURY FILM ELECTRODE ON SILVER SUBSTRATE

The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml.The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.     

DETERMINATION OF TRACEFLUORIDE AND MOLYBDENUM IN SERUM SAMPLE BY ELECTROCHEMICAL ANALYSIS

ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＴＲＡＣＥＦＬＵＯＲＩＤＥＡＮＤＭＯＬＹＢＤＥＮＵＭＩＮＳＥＲＵＭＳＡＭＰＬＥＢＹＥＬＥＣＴＲＯＣＨＥＭＩＣＡＬＡＮＡＬＹＳＩＳ￥ＬｉＺｅｎｇＷＡＮＧ；ＸｉａｏＬｉＺＨＡＮＧ，ＹｏａｇＹＵ，ＣＨＥＮＧＳｏｎｇＭＡ（Ｄｅｐ...     

FRACTAL STRUCTURE OF COLLOIDAL SILVER AND ITS EFFECTS ON SERS INTENSITIES OF CRYSTAL VIOLET

The surface-enhanced Raman spectra (SERS) of crystal violet on colloidal silver particles of different sizes and shapes were measured and the structural effect of the silver aggregates on the SEPS intensities was discussed in terms of fractal geometry. It is found that the SERS band intensities of crystal violet change significantly with the fractal dimension (D) of colloidal silver at 1.251.8.     

IN-SITU TIME-RESOLVED RAMAN SPECTROSCOPIC STUDIES OF SILVER ELECTRODE IN NaSCN SOLUTION

In-situ time-resolved Raman spectroscopy(TRRS)has been appliedon studies of electrochemical adsorption of thiocyanate at silverelectrode during potential cycles and potential step.It is shown thatsome dynamic information about the adsorption and desorption processes canbe obtained.     

EFFECT OF CONTENT OF CHLORIDE IONS IN SILVER BROMIDE ON THE ADSORPTION AND SENSITIZATION OF DYES

The adsorption and spectral sensitization of different types of dyes (cationic, anionic cyanine andmerocyanine) on silver chlorobromide were investigated by clectrochemical method, FT-IR and modelPhotographic emulsion. It has been found that addition of chloride ions can enhance the adsorption ofdyes and improve the ability of spectral sensitization. Different behaviors in adsorption and spectralsensitization appeared in different types of dyes depending on the structures and electric charges ofdyes. Merocyanine dye has the best adsorption and remarkable spectral sensitization ability on silverchlorobromide in comparison with other cyanine dyes. Experimental results also showed that there wasa good correlativity between adsorption behavior of dyes obtained by electrochemical method and spec-tral sensitization in model photographic emulsion, and the adsorption complex composed of dye andsilver halide was electro-inert but photo-active. The mechanism of spectral sensitization with variousdyes has been dis     

APPLICATION OF HIGH PRESSURE LIQUID CHROMATOGRAPHY AND MICROSEQUENCING METHODOLOGY IN THE STRUCTURAL ANALYSIS OF HUMAN HEMOGLOBIN VARIANTS

This paper reports the results of the analyses of 17 different Hb variants which were observed in 37 families. High pressure liquid chromatography (HPLC) was used to separate tryptic and thermolytic peptides of globin chains. The double coupling microsequencing technique can successfully be used for sequencing small or larger peptides.     

SYNTHESIS OF POLYCATECHOL WITH ELECTROCHEMICAL ACTIVITY AND ITS PROPERTIES

The electrochemical polymerization of catechol on platinum has been carried out using repeated potential cyclingbetween-0.2 and 1.1 V (versus SCE). The electrolytic solution consisted of 0.2 mol dm~(-3) catechol, 0.5 mol dm~(-3) NaCl and0.1 mol dm~(-3) Na_2HPO_4 with pH 8.72. Catechol can not be polymerized at pH≥10.12. Polycatechol has an electrochemicalactivity at pH≤4. The anodic and cathodic peak potentials of polycatechol shift towards more negative values as the pH ofthe solution increases from 1 to 4. The electrochemical activity of polycatechol hardly changes in this pH region, but itdecreases slowly with time. This is caused by oxygen in air, which leads to an irreversible oxidation of polycatechol. Thisproperty is favorable for protecting metals from corrosion. Raman and FTIR spectra of polycatechol and catechol are quitedifferent. AFM images of polycatechol films provide evidence that the image of the oxidized state of polycatechol ismarkedly different from that of the reduced one. This difference is caused by doping and dedoping of polycatechol.     

THE EFEFCT OF MAGNETIC FIELD ON POLYMERIZATION OF STYRENE IN THE PRESENCE OF POLYVINYL NAPHTHALENE AND POLYVINYL BENZOPHENONE

In the process of bulk photopolymerization of styrene initiated by AIBN decomposition polyvinyl benzophenone (PVB) can supply an effective cage for triplet-triplet energy transfer between PVB macromolecules and small molecules of AIBN to influence the molecular weight of polystyrene in weak magnetic field (less than 0.035T), that was different from the case of polyvinyl naphthalene (PVN) which supplied cages for this system only in the stronger magnetic field (more than 0.2 T) studies. It was found that in the same conditions, PVN could exert more tremendous influences on the bulk photopolymerizatiou system of styrene than PVB because in the stronger magnetic field the triplet PVN had much longer life time than PVB.     

STUDIES ON THE INITIATION MECHANISM OF CERIC ION AND ACETYLACETONE REDOX SYSTEM IN VINYL POLYMERIZATION

The initiation mechanism of acrylamide (AAM)polymerization using ceric ion/acetylacetone system as an initiator has been studied. The redox polymerization was revealed by the low value of overall activation energy of AAm polymerization. The structure of free radicals formed from above-mentioned initiation sytem were detected by radical trapping and ESR spectra techniques and the end groups of polymers obtained were determined by FT-IR spectra analysis method. Based on these results the initiation mechanism is proposed.     

THE PREPARATION OF ISOPOLYMOLYBDIC ACID-POLYANILINE FILM MODIFIED ELECTRODE AND ITS CATALYTIC EFFECTS ON CHLORATE IONS

The preparation method of H_4Mo(?)O_(26)-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.     

IN SITU FTIR AND UV／VIS STUDY OF THE ADSORPTION OF CYTOCHROME C ON GOLO ELECTRODE

ＩＮＳＩＴＵＦＴＩＲＡＮＤＵＶ／ＶＩＳＳＴＵＤＹＯＦＴＨＥＡＤＳＯＲＰＴＩＯＮＯＦＣＹＴＯＣＨＲＯＭＥＣＯＮＧＯＬＯＥＬＥＣＴＲＯＤＥＪｉｎＬＵＯ；ＺｈｏｎｇＨｕａＬＩＮ；ＳｈａｏＨｕａＨＵＡＮＧ；ＪｉｎＴｉａｎＷＵ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏ...     

STUDY ON CHEMICAL COMPOSITIONS OF 19 L AND LL CHONDRITES AND ITS APPLICATION IN TAXONOMY

Reported in this paper are precise INAA data on 19 L and LL chondrites (7 Chinese chondrites and 12 from other countries). The L and LL chondrite data normalized to Mg and to CI chondrite indicate that for several lithophiles (V, Al, Cr and Mn), the extent of scatter is low, similar to that observed in carbonaceous chondrites. The average concentration of siderophiles in the LL group is lower than that in the L group.On the basis of olivine composition and atomic ratio (Ir/Au), we reclassify the five previously labeled L ehondrites as LL members. The atomic ratios of Ir/Au in the LL chondrites are lower than those in the L chondrites (the division is set at an Ir/Au ratio of 2.5). The atomic ratio of Ir/Au appears to be a useful classification parameter for ordinary chondrites. Therefore, it can be considered as a new taxonomic parameter. Of the elements studied, Br, a high volatile, seems most likely to show thermometamorphic effects, depending on petrologic types. The concentration of bromine and the     

SURFACE ENHANCED RAMAN SPECTRA OF PHENYLMERCAPTOTETRAZOLE AND MERCAPTOBENZOTHIAZOLE ON SILVER

Normal Haman Spectra(NRS) of solid PMT (1-phenyl-5-mercaptotetrazole) and MBT (2-mercaptobenzothiazole) and their surface enhanced Raman spectra (SERS) adsorbed on the surface of the silver subcolloidal particles are reported and compared.It is supposed that PMT adsorbed on silver with both N and S atoms whereas MBT may be adsorbed on silver through S atom.     

ELECTROCHEMICAL POLYMERIZATION OF ANILINE IN PHOSPHORIC ACID AND THE PROPERTIES OF POLYANILINE

The behavior of the electrochemical polymerization of aniline in a weak acid, phosphoric acid, is very similar to that in strong acids, i.e. its polymerization rate increases quickly with the electrolysis time. The FTIR spectra of polyaniline samples synthesized in phosphoric acid indicate that the counter ion H2PO4^- is present in both the oxidized form and the reduced form of polyaniline. The counter ion plays an important role in adjusting the pH value at the electrode surface of polyaniline during the oxidation and reduction processes. As a result, a pair of redox peaks still appear in cyclic voltammograms of polyaniline in a solution of sodium sulfate of pH 5.5 and in a solution of NaH2PO4 of pH 7.0,respectively, at low potential scan rate; and the color of polyaniline film also changes with applied potential at pH 7.0. Thus,the pH region for the electrochemical activity and the electrochromism of polyaniline is extended to pH 5.5 for a solution of sodium sulfate and to pH 7.0 for a solution of NaH2PO4. The conductivity of polyaniline is 3.3 S cm^-1, depending on the concentration of phosphoric acid used in the stage of polymerization of aniline. The result of elemental analysis of polyaniline is presented here.     

ICHNOFACIES IN LATE PALEOZOIC DEEP-WATER SLOPE SEDIMENT OF JUNGGAR BASIN AND ITS ENVIRONMENTAL ANALYSIS

This paper mainly discusses 15 kinds of ichnogenus found for the first time in the study area from the water depth distribution, body size of trace fossils and the relationship between sedimentary environment and deep-water ichnofacies, based on the summarizing of the sedimentary character of deep-water slope environment in the study area. According to the relationship between the type of turbidite and the combination of trace fossils, 15 kinds of ichnogenus are divided into two types, transition type Zoophycos ichnofacies and deep-water type Nereites ichnofacies. The former is mainly distributed in the transitional area between proximal to distal area of turbidite and the latter in the distal area.     

CONFORMATION OF Asn-Ala-Gly-Ala-Asn AND ITS DERIVATIVES IN SOLUTION——A CD SPECTRA ANALYSIS

The CD method has been used to study the conformation of the pentapeptido Asn-Ala-Gly-Ala-Asn(NAGAN) and the tetrapeptides Asn-Ala-Gly-Ala(NAGA) and Asn-D-Ala-Gly-Ala-NH_2(NDAGA) in solution. At low pH the far UV CD speetra of aqueous solutions of NAGAN show a positive extremum at 215 nm and a negative extremum at 232.5 nm. Under this condition, the molecule of NAGAN may assume a β-turn structure. In the solution of 90% ethanol or tri-fluoroethanol at pH 5.8, NAGAN reveals CD spectra with a negative 218 nm extremum. The[θ]_218 values are independent of the concentration of NAGAN. Au intramolecular β-pleated sheet-like structure is suggested to explain the negative peak.The CD spectra of NAGA show a single positive band at around 215 nm. The possibility of forming a β-turn by NAGA has been discussed. Only the 196 nm negative extremum canbe seen in the spectra of NDAGA: It seems as if NDAGA is in the form of a random coil.According to the report made by Pan et al. all these peptides possess analgesic