Binary systems of alcohols and aprotic solvents have been studied systematically by NMR measurements. ~1H, ~(13)C, ~(15)N and ~(17)O chemical shifts and proton T_1 have been measured. The effects of solvents on ~1H and ~(13)C chemical shifts of alcohols were discussed. ~(13)C chemical shifts of α-carbon atom of alcohol were used to determine the ability of solvents to distort or disrupt the structure of alcohol, while their ~1H che-mical shifts were used to measure the strength of hydrogen bond between solvents and alcohols. The result was obtained showing that the stronger the solvent as a donor, the stronger its ability to disrupt the structure of alcohols.
Chemical shifts of solvents hae also been measured. It was thought that their ...

The enumeration of stereoisomers is performed by concerning the ligand substitution as coloring of vertices in the skeleton of a molecule. The colored fragments are classified into species denoted by the symbol (α_1~(n1), α_2~(n2), …, α_f~(nf)) in which α_i(i=1, 2,…,f) being the number of vertices colored identically and n_i standing for its appearances. They satisfy: α_1>α_2>…>α_f and
n_1α__1+n_2α_2+…+n_fα__f=N
where N is the total number of skeleton vertices. By means of symmetry and com-binatorial analysis, both total number of skeleton vertices. By means of symmetry and combinatorial analysis, both the chiral and achiral isomers can be enumerased respectively for each substitutional species. For example, species (1~N) means ligands differ completely one another and the number of chiral isomers can be computed by using the following formula
M_c=N!/|G|...

The electronic structures and conformations of non-polar-substituted 4-n-propyl-fentanyl and polar substituted 4-methoxymethyl-fentanyl and 4-methoxycarbonyl-fentanyl were investigated by the method of quantum mechanics. The results showed that the cause of effect of 4-substituent on biological activity not that change of conformations but that electronic factors. The 4-non-polar-substituents have not con-tribution upon increase of activity. The 4-polar-substituents form new additional negative electronic region, which may be the main assistant site interacting with receptor, the additional negative electrostatic potential region may interact with receptor at a new site or the site in common with amide oxygen. It is no doubt that the additional negative electrostatic potential field generated by the 4-polar-substituent dramatically increases the analgesic activity of the fentanyl derivatives.

A LIF technique that employs a varying view field has been developed to give quantitative measurement for the vibrational relaxation rates of I_2 B(v′=43) state in supersonic jets. The data for Ar, N_2 and CO are obtained for the first time. The results have shown that the measured vibrational relaxation rates in cold jets bear an inverse tempeature dependence. For He and H_2 carrier gases, the dominant relaxation process is the usual △v=-1 process. For Ar, N_2 and CO, however, the most probable relaxation pathway is no longer Δv=-1 process, which apparently violates the energy gap law. These observations are adequately explained by a metastable complex formation mechanism.

The interactions between NO and transition metal surfaces have received consi-derable attention because of the practical importance for NO removal in industrial and automotive catalytic converters. Adsorption-desorption kinetics of NO on Pd(poly) has been studied with Thermal Desorption Spectrum(TDS)and Molecular Beam Relaxation Spectrometry (MBRS) methods. There are three different models (simple, coverage dependence of sticking coefficient and branch process adsorption-desorption models) for explaining experimental results of MBRS in different surface temperature ranges and different modulation frequencies. Best fits to the kinetic parameters characteri-zing the two adsorbed states are as follows:
E_(1d)=104.2±2.7 kmol~(-1), v_(1d)=10~(13.5±0.9)S~(-1)
E_2d=74.4±0.8 kJ mol~(-1), v~(2d)=10~(10.3±0.2)S~(-1)
Finally, the mechanism of unsual adsorbed state ...

The kinetics of the gas-phase thermal isomerization of epoxypropane has been studied over the temperature range 1045-1175 K in a single-pulse shock tube. Uni-molecular isomerizations to propionaldehyde, acetone, methyl vinyl ether and allylol account for about 65% of the primary reactions which occur by first order, homoge-neous, non-radical processes. Secondary reactions, that make quantitative determina-tion of the individual rate constants difficult, were reduced by the addition of radi-cal scavenger nitric oxide.
k_(propionaldehyde)(s~(-1))=10~(14.3)exp(-262 kJmol~(-1)/RT)
k_(acetone)(s~(-1))=10~(14.0)exp(-268 kJmol~(-1)/RT)
k_(methylvinyl ether)(s~(-1))=10~(13.4)exp(-264 kJmol~(-1)/RT)
k_(allylol)(s~(-1))=10~(13.9)exp(-275 kJmol~(-1)/RT)
A biradical mechanism for the isomerization of epoxypropane has been preferred. It adequately exlained kinetic observations. The RRKM theory of unimolecular reactions was applied to explain the thermal isomerization of epoxypropane.

Solubilities of nitrogen in binary mixtures of n-octane and iso-octane have been measured over the temperature range of 20 to 70 ℃ and at pressures up to 130 atm. Experimental results can be fitted by the following equation
lnx_(N_2)=A+Bp_(N_2)+Cp_(N_2)~2+Dlnp
From the experimental results, the partial molar volume of dissolved nitrogen and the Henry's law constants have been calculated.

The stability constants of coordination compounds formed from some α-amino acids(αA) DL-P-Fluoro phenylalanine, DL-Serine, DL-Valine, DL-Alanine and α-amino-isobutyric acid with Cu(Ⅱ) were measured by Ion-Selective Electrode at 25±0.1, 35±0.1 and 45±0.1 ℃ in water, 30% ethanol and 50% ethanol solution in the presence of 0. 16 mol·dm~(-3) KNO_3. The order of stability of the Cu(Ⅱ)-αA coordination compounds is in 50% ethanol solution>in 30% ethanol solution>in waterat 35±0.1 ℃.
Linear relationships not only existed between the stability of Cu(II)-αA coordination compouds and the base strength of ligands but also existed between the formation enthalpy of coordination compounds and the protonation enthalpy of the ligands, and between the formation entropy of coordination compounds and the protonation entropy of the ligands as well.
25—45 ℃ ΔH~...

Electrochemical methods, ESR-Electrochemical methods and Spectroelectrochemical methods have been used to make a detailed study of the electroreduction of phenol red in alkaline DMSO with tetrabutyl ammonium hydroxide as supporting electrolyte. It was found that the free radical thus generated was consumed through a second order disproportionation reaction.

A computer interface technique was applied to the data collecting system of the apparatus for measuring freezing points of mixtures. The sampling of experimental data, the plotting of heating curves and calculating of freezing points and activity coefficients were completed automatically. The apparatus is capable of measuring the freezing point of mixtures with a reproducibility of ±0.001K and the solvent partial molar excess Gibbs free energy with a reproducibility of ±0.1 J mol~(-1).
In this paper, the solvent activity coefficients of binary associated mixtures have been measured for n-propylamine, isopropylamine, n-butylamine, isobutylamine, n-amylamine, isoamylamine, diethylamine, diisoproylamine, triethylamine and tributy-lamine in benzene and p-xylene. The mole fraction concentrations of solute are ranged from 0 to 0.1 and 0 to 0.2 for benzene and p-xylene respectively. The solvent activity coefficients for all systems are greater than unity. A modified three parameter association model, which contained a dimerization constant K_2, a formation to treat the experimental activity coefficients. Under the condition of w=0, this three-parameter model is reduced to the ideall association model. It is shown that the association constants K_2 decrease in the following order:
Primary>secondary amines>>tertiary amines
A similar order...

The mechanisms of electrochemical reduction and electrochemical oxidation of Indigo Carmine were investigated by means of thin-layer spectroelectrochemical tech-nique at a SnO_2-quartz optically transparent electrode cell.
The formal potentials and electron transfer numbers of the reduction of Indigo Carmine were determined at different pHs. The results showed that the reduction of Indigo Carmine at SnO_2 electrode is a quasireversible two-electron transfer process and its oxidation is a irreversible electron transfer process. The mechanisms of the electroreduction and electro-oxidation were discussed on the basis of the spectrum recorded in situ during the electrochemical process.

The existence and thermal stability of H_2O in 12-molybdophosphoric acid (PMA) have been studied by temperature programmed desorption-mass spectrography (TPDMS) and infrared spectrography (IR).
A PMA sample containing 19.1 H_2O/P, H_3(PMo_(12)O_(40))·17.6 H_2O, was prepared, its water content was determined according to Fig.1. The TPD MS spectrum of H_2O (m/z=18) in PMA (solid line Fig.3) was recorded after vacuum outgassing(0.27 Pa) at 290 K (the total time of outgassing in the range 77.4-290 K was 142.5 min). Separated spectra (Fig.3) and their parameters simulated by spectrogram superposition method~[7] and consulting table method~[8] (Table) show that there exist 7 kinds of H_2O in PMA.
In situ IR spectra for PMA at different conditions (Fig.4) revealed...

The Ni montmorillonite catalyst is prepared from raw bentonite and its activity of catalytic oxidation is evaluated in the desulfuration from liquid phase. The deter-mined and analysed results of DTA and TPR show that the exchangeable Ni-ions between the sheets of the montmorillonite can immediately combine with oxygen to form oxides under higher temperature. The effect of the oxidation on the drop of the catalytic activity of Ni montmorillonite is probably more important than that of the Ni-ions embed in the sheet structure due to heat-activation.

In a simple experimental condition without dustproof equipment, satisfactory spherical magnetite particles of narrow size distribution had been obtained by aging ferrous hydroxid gels in the presence of nitrate ion. this note reports a new result according to the modified experimental procedure, in which included the mixed of reactants, elimination of oxygen and magnetic separation etc. According to transmis-sion electron micrographs the mean diameter of particles is about 0.5 μm.

With an attempt to improve our proposed one-step method for direct synthesis of CsTmI_3 from CsI:HgI_2:Tm (molar ratio 1: 1: 1) mixture, we have investigated the mechanism of CsTmI_3 formation under this condition by using DTA and X-ray powder diffraction methods. The results obtained indicate that there are two pathways leading to formation of CsTmI_3 from this mixture:The first one involves the reaction between HgI_2 and Tm at 314 ℃ with formation of TmI_2, which, in turn, acts as an interme-diate for CsTmI_3 formation is intermediated by CsHgI_3 (a new phase) formed from CsI and HgI_2 at 210 ℃ and this intermediate will convert to the final product CsTmI_3 in the presence of Tm at 530 ℃.
In addition, we have also studied the phase transition of CsTmI_3. It is found that there are three reversible endo-thermal peaks appeared at 510 ℃, 648 ℃ and 665 ℃ in DTA curve. The X-ray analysis indicated that the peak at 510 ℃ could be assigned at the phase transition of CsTmI_3 and the peak at 665 ℃ is responsible for its melting point. The peak at 648 ℃ seems most likely to be another phase transtion.

Several ruthenium complexes are prepared and the absorption and emission spe-ctra of their solutions in EtOH-MeOH at room temperature are reported. The emis-sial maxima of three complexes 4-substituted 2,2′-bipyridyls occur between 550-650 nm, there is strong absorption down to 500 nm as dyes for possible use in lumine-scent solar collectors.

The titled isomerizaton of methylsilene has been studied at ab initio level. Theharmonic vibrational frequencies of reactant, product and transition state, the barrier energy, reaction heat, equilibrium constant and rate constant are calculated. The results indicate that this reaction is exothermic, spontaneous and high temperature above 900 K is favourable for the isomerization. The prediction is in agreement with experiment.

In this study, Ni-ZrO_2 and Ni-WC composite electrodes were prepared with the technique of composite electroplating, and used in the cathodic reduction reaction of H~+ in acid solution. The electrocatalytic properties and true surface area of the electrodes were determined by electrochemical and physical methods. It was found that the composite electrods had higher catalytic activity than pure Ni plated electrode for reduction reaction of H~+. The effect of content of the particles in the composite electrodes on the electrocatalytic property of the electrodes was discussed. Our results suggest that there is a possibility of preparing various new types composite electrode with electrocatalytic activities for certain redoxreaction system through the technique of composite electroplating by selecting proper materials.

The low temperature infrared spectroscopy was applied to investigate the adsorp-tion of NO and CO on CuO/γ-Al_2O_3. The measured infrared bands were asigned. The results of alternate adsorption and coadsorption of NO and CO exhibited that Cu~(2+) and Cu~+ sites coexist on the surface of oxidized CuO/γ-Al_2O_3 and the selective ad-sorption of CO/Cu~+ and NO/Cu~(2+) was observed.

In this paper we defined regidly the microscopic hole existing in molten salt and established the embedding method for locating the hole and calculating the size of the hole. To describe the statistical distribution of the microscopic holes better we introduce the RDF of the microscopic hole. In molten 900 K LiCl we finded that there were about 20 microscopic holes with the radius larger than 0.10 nm, the largest is 0.18 nm. The RDF of the microscopic holes shewed us that both g_(h-Li~+) (r) and g_(h-Cl~-)(r) have two peaks. The maximal values of the two peaks are about 0.5. The coordinated number of Li~+ ion with microscopic hole is about one and that of Cl~- ion is about 1.5. Using this method we can study the distributional character of different radius of the microscopic holes.

The kinetics of anodic O_2 evolution on Ti/RuO_2+TiO_2 anodes was studied in acid solutions, by with two Tafel regions have been confirmed. At low current densities i.e. the first Tafel region ?φ/lgi=2.303RT/((1+β)F, whereas at high cds i. e. second Tafel region it is 2.303RT/βF. In the low current densities region, the reaction order with respect to α_w is 4. For the second Tafel region the reaction order is 2.
The kinetic data obtained show that the rate determining step of the anodic evo-lution of oxygen on Ti/RuO_2+TiO_2 anodes in acid solutions is
...

The bi-exponential decay of the luminescence of electronically excited uranyl ions in perchloric acid has been investigated with detailed study of the time resolved lu-minescence spectra and Raman spectra of uranium. While the U(Ⅵ) concentration is in the range of 0.01-0. 1 molL~(-1) and the pH is≤1.5, the luminescence decay is sin-gle exponential and the luminescence spectra are independent on the delay time and the U(Ⅵ) concentration with peaks at 488.0, 510.0, and 533.0 nm, which belong toaquo-uranyl ions. While the pH of the solution is increased to higher than 2.8, the luminescence undergoes bi-exponential decay and the luminescence spectra with 0.2 μs delay time change dramatically with increasing the pH and the U(VI) concentration, and are different from the spectra with 20 μs time delay, which consist of three peaks at 500.0, 518.0, and 538.0 nm. From the thermodynamic data of the hydrolysis of uranyl ions and the dependence of the Raman spectra of U(VI) on the pH and the uranium concentration the later spectra can be identified as the spectra of the dinuclear hydrolysis product of UO~(2+)_2 and (UO_2)_2(OH)~(2+)_2. All the measured time resolved spectra can be fitted to the linear combination of the spectra of aquo-uranyl ions and (UO_2)~(2+)_2(OH)~(2+)_2 satisfatorily. The conclusion that the bi-exponential decay is attributed to UO_2(H_2O)~(2+)_x and (UO_2)_2(OH)~(2+)_2 ions has been withdrawn.

The nature and mechanism of solubilization of the block copolymer of polyoxye-thylene-polyoxypropylene glycols-Pluronic were investigated and the results showed that only the samples with appropriate HLB value were valid for solubilization. In aqueous solution of L64 the aromatic hydrocarbon could be solubilized, while the alkanes almost could not. The lowest concentration of L64 for solubilization decreased with the increase of the temperature.
Water could also be solubilizated in the xylene solution of L64. The size of the inverse micelles of solubilized water was much bigger than that of the micelles of solubilized xylene.
Ultraviolet and NMR spectroscopic studies showed that the xylene and toluene were included into the polyoxypropylene chains at the interior of the micelles for the PPO-PEO block copolymer.

In this paper the bonded tableau method for many-electron systems, which was recently proposed by authors, is exploited to study the chemical interactions of sub-systems. Two approaches are given for constructing symmetry adapted states of par-tition system, namely the method based on the non-standard basis projector of the permutation group and the coupling method of bonded tableaux. Based on the par-tition states, the interaction energy between two subsystems is investigated. The present method can be easily used, in valence bond (VB) structure interaction or configuration interaction (GI) level, to handle with the general problems of partition system, such as the problems of inter- or intra-molecule interaction.

The voltammetric characteristics of RuO_2 electrode has been studied by means of cyclic voltammetry and pulse polarography. In the potential range of 0.2-0.8 V, there are two redox reactions as follows:
RuOOH<+>RuO_2+H~++e
RuO_2+H_2O<=>RuO_3+2H~++2e
but not one redox reaction to turn Ru~(3+) into Ru~(4+).
The oxygen-deficient structures are the active sites whose disappearance results in the deactivation of the electrode.

In this paper, we have studied the mechanism of intermolecular energy transfer of Rh6G and Cresyl Violet which form a donor-acceptor pair in mixture solution. The relationship between the fluorescence intensity of Cresyl Violet and its concentration has been emphatically studied. The effect of self-absorption of Cresyl Violet upon the fluorescence intensity is appreciable and can not be ignored, as the concentration of Cresyl Violet being high. Considering the effect of self-absorption, we have mo-dified the theoretical formula obtained by Birks, and deduced the relative expressions of acceptor fluorescence intensity and acceptor concentration for both radiative transfer and Forster transfer processes.

Relationships between the activity of a certain component and the product of ac-tivities of three components, Φ, which may be the activity of the compound, on boundaries of two-phase region in ternary systems have been studied. An important formula expressing above mentioned relationships has been derived. It is a common expression which involves various kinds of formulae for two-phase region in ternary systems. At the same time, we analyzed in detail the influence of the direction of tie-line on relationships between the activities. A parameter θ is empolyed in order to overcome the difficulties encountered in integration in the two-phase region. In addition, we consummated Krivsky and Schuhmann's rule on the basis of certain results in the paper.

The mechanism of the thermolysis of oxetane to form ethylene and formaldehyde has been studied in detail by semiempirical molecular orbital theory. The calculations have been carried out using a new general purpose quantum mechanical molecular model AM_1 presented by M. J. S. Dewar et al in 1985,and performed with GAUSSIAN 86 program. The various critical points in the region of the reaction have been fully optimized with Berny gradients and transition structures (TS) have been confirmed by frequency analysis. By calculations, we concluded that: 1) concerted supra-supra reaction path doesn't exist and the critical point involved is a second-order asddle point with two negative eigenvalues; 2) concerted supra-antara approach is found to proceed via a very high energy transition state; 3) the favoured reaction pathway is found to proceed via a stepwise approach characterized by diradical intermediates. The stepwise approach has two different pathways, one of them is to cleava carbon-car-bon bond firstly and then carbon-oxygen bond, it involves gauche intermediate and corresponding transition states. Another stepwise pathway is to break carbon-oxygen bond at first and then carbon-carbon bond, it proceeds vis a gauche or a trans intermediate and corresponding transition states. The two stepwise pathways coexist and compete each other.

Acidity of La~(3+)-exchanged HY zeolite has been studied by the measurements of adsorption on the in-situ IR system and MAS-NMR method. The results show that:
1.The IR bands at 3631 and 3556 cm~(-1) are all assigned to hydroxyl group of strong acidic sites. The band at 3531 cm~(-1) is assigned to nonacidic hydroxyl group, since it has no interaction with ammonia. It is possible that two hydroxyl groups coor-dinate with one La~(3+) directly; the band at 3520 cm~(-1) is assigned to weak acidic hy-droxyl group, because it has weak interaction with ammonia, and one hydroxyl group may coordinate with one La~(3+) directly.
2. The hydroxyl group at 3638 cm~(-1), which is in supercage of HY Zeolite, is of heterogeneity of actidity resulting from silicon atoms with different numbers of coordinated Aluminium.

The impedance plane plots for four ISEs, two liquid membrane bile salt ISEs and two PVC membrane Ca ISEs based on ETH 1001 and phosphate, were measured from 65 kHz to 0.01 Hz. All the impedance spectra obtained showed two semicircles and a Warburg impedance (Fig.1). The bulk resistance of membrane, R_b, and the charge-transfer resistance, R_(ct), were estimated from the high frequency and the low fre-quency semicircles respectively. The activation energy for ion transport in membrane, E_a, and the apparent standard exchange current density, i°_0, were calculaed from the R_b varied with temperature and the R_(ct) varied with the ion concentration in bathing the R_b values are not, and the E_a values and R_b values for two liquid membrane ISEs are also the case, The E_a values for the former are three times larger than the than in liquid membrane. The ETH 1001-based Ca ISE is a very good Nernstain sensor. The i°_0 value of it bathing in Ca~(2+) solution is 1.9×10~(-4) A·cm~(-2). The potentionetric responses of the two liquid membrane ISEs are near Nernstain. The i°_0 of them bathing in the potential-determining ion solution are in 1×10~(-6)-6×10~(-5) A·cm~(-2) range. The Warburg impedance was eliminated by the strong anion surfactant added in bathing solution. It was shown that the diffusion of the potential-determining ion near the membrane/solution interface is inhibited, then the potentialmetric response for the potential-determining ion is disturbed.

The rate constant of very fast chemical reaction generally can be measured by electrochemical methods, but can not by the thin layer electrochemical methods because of the influence of diffussion effect. Long optical path length thin layer cell (LOPTLC) with large ratio of electrode area to solution volume can be used to monitor the fast chemical reaction in situ with high sensitivity and accuracy. It enables the absorption spectra to be measured without the influence of diffussion effect.
In the present paper, a fast chemical reaction of Alizain Red S (ARS) with its oxidative state ha been studied. The reaction equilibrium constant (K) under different potentials can be determined by single step potential-absorption spectra in LOPTLC. An equilibrium constant of 7.94×10~5 l·mol~(-1) for the chemical reaction has been obtained from the plot of lgK vs. (E-E~0′_1). Rate constant (k) under different potentials can be measured by single step potential-chronoabsorptionmetry. At rate constant of 426.6 l·mol~(-1)·s~(-1) for the chemical reaction has been obtained from the plot of lgK vs. (E_E~0′_1) with (E-E~0′_1)=0.

The densities of the mixtures of N,N-Dimethylformamide (DMF) and water(w) have been measured at ten temperatures from 278.15 K to 318.15 K with the vibra-tingtube density meter(Anton Paar Model DMA602). Then the excess molal volumes V~E of solutions and apparent and partial molal volumes of DMF over the range of mole fraction 0-1 have been determined. Comparing these quantities as functions of mole fraction of mixtures with the standard entropies of transfer for NaCl from water to DMF-H_2O mixtures as function of mole fraction of mixed solvent we found out there is a correspondence between the V_(DMF) varied with x and the standard entropies of transfer of NaCl. Both have the extremes at x=0.075. Therefore the structure of solution have been discussed. It might be considered that monomeric DMF molecules have been trapped in a quasi-clathrate "cage" made up of 12 water molecules at x=0.075 forming the possible closest packing of particles.

A dynamic algebraic h_(15) is formed by using the semiclassical potential surface for AB+CD. The V-V energy transfer and the expectation of the potential are calculated; the selection rules are discussed under the first-order approximation of the group parameters.

The interaction of water with solvents in H_2O-TBP-CCl_4 system and H_2O-p-dio-xan-CCl_4 system is studied with IR method. The absorbances of free water, 1:1 and 1:2 complex are observed and the absorbance frequencies of each species are assigned. In H_2O-TBP-CCl_4 system, there exists not only symmetric 1:2 complex but also unsymmetric one. The water molecule in unsymmetric 1:2 complex is considered to be hydrogen bonded with two kinds of oxygen atom in TBP. And the hydrogen bonds are different in strenghth. Because of diffeent spatial configurations of solvent molecules around water, more than one kind of 1:2 complex exist in H_2O-p-dioxan-CCl_4 system.

The process of glass transition on the non-crystal SeTe_8Sb_1 has been researched using low temperature differential scanning calorimetry (DSC). The following conclusions are deduced: this process is a second-order phase transformation, the stronger endotherm displayed in it is imputed to hysteresis of the transition. The temperature of glass transition in heating process decrease with reduction of the cooling rate while forming glass. The activation energy of glass transition quickly increases from 174 kJ·mol. (at quenching rate ~10~4 K·min~(-1)) to 399 kJ·mol~(-1). (at cooling rate ~10 K·min~(-1)) So that the glass obtained at lower cooling rate is more stable than that obtained at higher rate.

The crystal structures of the title compound (Ⅰ) and (Ⅱ) have been determined by X-ray diffraction. Crystal data are: C_(17)H_(15)NO_3(Ⅰ), triclinic, α=0.7308(2) nm, b=0.8845(3) nm, c=1.1323(3) nm, α=100.03(2)°, β=104.81(2)°, γ=97.20(2)°, V=0.6856(3) nm, Z=2, R=0.047 and C_(18)H_(17)NO_3(Ⅱ), monoclinic, a=1.1006(3) nm, b=1.1172(2) nm, c=1.4046(3) nm, β=102.78(2)°, V=1.5337(6) nm, Z=4, R=0.055. The molecular conformation is cis form for compound Ⅰ and trans form for compound(Ⅱ).

In this paper, two different kinds of B-Z type oscillating reactions have been described. One is the couple catalyzed oscillating reaction with vanillin(OA) as the organic substrate. Another is the uncatalyzed oscillating reaction with 2,7-dihydroxynaphthalene (DN) as the organic substrate. Effects of many factors on the oscillations have been examined. According to the FKN mechanism, a simple model for the catalyzed oscillation has been proposed. Each of experimental results can be explained with this model. It is found thad the model can also be employed in the uncatalyzed oscillating reaction supposing that the organic substrate DN can play the role of catalyst as the metal ion in the catalyzed oscillating reaction.

The crystal structures of 2,3,7,8-tetrachlorodibenzo-p-dioxin(2, 3, 7, 8-TCDD) and its analogues have been determined. And the semiempirical INDO calculations for this type of compounds have been undertaken. Their characteristics of electronic structures were discussed. The possible active centers which can interact with biological receptor were also proposed.

In this paper, B-02 catalyst, developed by Yanshan Synthetic Rubber Factory and used in two large production plants, was investigated by means of pulse technique and temperature-programmed techniques, as well as XRD and FT-IR techniques. Three related iron compound, magnesium ferrite, hematite, and maghemite, were also studied.
XRD showed the presence of two crystallographic phases, viz., magnesium ferrite and hematite, in the B-02 catalyst.
A combination study of the reduction behavior of B-02 was established, comp...