The molten salt solutions NaCaF_3, Na_2CaF_4 and Na_3CaF_5 have been studied by molecular dynaAncs simulation. The siumlations show that the radial distIibution functions in the three mixture systems are very much closed to each other. The molar ndking enthalpy obtained from the simulations reproduced the experimental value very well. The relation between the dring enthalpy and the depth of Na~+ cation's potential well have been found to bd nearly linear. The selfdimision coefficients of Na~+, Ca~(2+) and F~- ions in the Na_2CaF_4 system, which is an eutectic mixture with the component ratio NaF:CaF_2=2:1, appeared anomaly large.

The influence of fluorine or/and aAnne substituents to the mechainsm of cycloaddition reaction of ethylene and formaldehyde has been studied by using senilemPirical molecular orbital theory UAM1 presented by M.J.S. Dewar et al in 1985, and performed with GAUSSIAN 86 program. Three chendcal reactions (C_2H_4+COF_2, H_2NHC=CHNH_2+H_2CO and H_2NHC=CHNH_2 +COF_2) have been studied in detail. Thevarious critical points of all the reactions studied have been fully optimized with Berny gradients and transtiton structures have been confirmed by frequency analysis. From the results we concluded that: 1) All the reaction pathways studied in this work are found to proceed via a two-step approach characterized by diradical gauche intermediates and the rate determining step is the first step for all the three reactions. 2) The fluoride or/and amine substituents can all reduce the potential energy barrier of the cycloadditon reaction of ethylene and formaldehyde, and amine is more favourable than fluoride.

The values of reaction enthalpy of B(OH)~-_4 with polyhydroxy comPounds were deterthened by using calorimeter at 298.2 K. The coordination enthalpy of boric acid with polydydroxy compounds and the standard enthalpy of formation of the coordination ions were calculated. The coordination numbers of the coordination reactions of B(OH)~-_4 with mannitol, d-sorbitol, glycerol and a-dglucose were determined by the values of coordination enthalpy. For maunitol and d-sorbitol, the number of coordination with B(OH)~-_4 is 2; for the glycerol and α-d-glucose, it is 1.

Mossbauer spectroscopy is uesd to study the photostimulated luminescence material BaFBr:Eu for the first time. The results from Mossbauer study support the conclusion obtained from luminescence studies, that is in BaFBr:Eu, the ltalnescence effect of Eu~(2+) is much higher than that of Eu~(3+), Eu~(2+) lundnescence Anght be enhanced by Eu~(3+). Meanwhile, Mossbauer study may also provide useful information on the interaction of phonon on luminescence centers. All thoes results are helPful to the understanding of luminescence process.

Butane reactions on SO~(2-)_4/ZrO_2 type solid superacids at ambient temperature were studied. The butane isomerization selectivity is higher than 95% while the total reaction conversion is lower than 50%. The rate of the butane isomerization reaction follows the rate law of a first-order reversible reaction. The reaction conversion, rate constant and activation energy of the isomerization reaction are dependent on the superacidity of the solid catalysts. As the H_o of the catalysts is increased, the reaction conversion and rate constant are increased and the activation energy is decreased. The butane isomerization at ambient temperature is a od probe reaction for the characterization of solid superacidity.

Superconductivity of Cu_2S doped Bi-Pb-Sr-CaCu-O system has been investigated by resistance, X-ray diffraction and XPS measurements. It was found that an appropriate amount of Cu_2S can lower the optimum sintering temperature and enhance the formation of the high-T_c phase. The analyses of XPS spectra reveal that the addition of Cu_2S causes the negative chemical shifts of the Cu 2p_(3/2) main peaks and the diminution of their satellite areast suggesting that the hole contents decrease with increasing Cu_2S concentration.

The mechanism of the synthesis of platinum carbonyl clusters [Pt_3(CO)_6]~(2-)_n(n=3,4) in cages of NaY was studied by IR, EXAFS ~(13)CO exchange reaction and No interaction. The results suggest that oaldized Pt species in NaY cages reacts with CO at 300-373 K to form PtO(CO) (σ_(CO)=2110 cm~(-1)) which aggregates into "Pt_3(CO)_6"(σ_(CO)=2112, 1896 and 1841 cm~(-1)) and eventually converts into dark-green carbonyl cluster [Pt_(12)(CO)_(24)]~(2-). The carbonyl "Pt_3(CO)_6" can exchange with ~(13)CO very quickly at 298 K but the exchange reaction between ~(13)CO and intrazeolite Pt carbonyl clusters [Pt_3(CO)_6]~(2-)_n (n=3,4) proceeds slowly even at enhanced temperature such as 343 K. It is interesting to find that NO breaks successively the intra and inter-tri nal Pt-Pt bonds of the Pt_(12) carbonyl clusters (even at 298 K) and the "Pt_3(C)_6" formed is further reacted to give PtO(CO) with the formation of N_2O and CO_2 in the gas phase. Pt_(12)(CO)_(24)]~(2-) can be reversibly regenerated from the Pt subcarbonyls such as PtO(CO) and "Pt_3(CO)_6" inside NaY by reacting wich CO at 300—353 K.

β-cyclodextrin (β-CD) induced aggregation and micelle formation of cetyltrimethylammnium bromide (CTMAB) in aqueous solution is demonstrated by the dual fluorescence of p-N, N-dimethylaminobenzoic acid (DMABOA) typical of the twisted intramolecular charge transfer (TICT). The locally excited (LE) state of DMABOA is proved to have the characteristic of intramolecular charge transfer (ICT) with a polarity higher than that of ground state but lower than that of TICT state. The peak positions of the two fluorescence bands and their intensity ratio are employed to probe the interaction of β-CD with CTMAB. It is conc1uded that β-CD induces CTMAB aggregation as well as micelle formation and may change micelle structure. The results also indicate that TICT in aqueous solution may be affected by the anisotropy or viscosity of the medium, increasing viscosity disadvantaging the TICT process.

A series .of LaMnyCo1-yO3 compounds were prepared by the complexation method with citric acid. XPS was used to investigate the oxygen state in perovskite-type (ABO3) Complex oxide LaMnyCo1-yO3 catalysts. The result showed that three oxygen species (α，β，β') are present in the oxides, and that theα-species is the active oxygen species in catalytical oxidation.

A series of catalysts such as Ru/SiO2, Co/SiO2 and Ru-Co/SiO2 were prepared by using the precursors of Ru, Co and Ru-Co carbony1 clusters. The catalytic performance in hydroformylation of ethylene showed that the activity and selectivity on a series of RuCo/Sio2 for C3-oxygenated products are much higher than those on Ru/SiO2 and Co/SiO2 catalysts. The adsorption of CO on reduced Ru-Co/SiO2 exhibited a hand at l680cm-1,which was assigned to the C- and O- ended CO chemisorbed on Ru-Co/SiO2 catalysts. The IR spectra of the reaction of C2H4+CO+H2 with Ru-Co/SiO2 catalysts showed bands at 1582 and 1555cm-1, which may possibly be assigned to formyl and C3-acyl species on the surface, they play very important role for the formation of C3-oxygenates in hydroformylation of ethylene.

The title reactions with R=Me, Et, n-Pr were studied in a temperature range of 298-313K by spectrophotometry. It was found that the rate with respect to [complex] is unity and that to [amine] is fractional. A linear relationship between [amine]/kobs and [amine] was observed, where kobs stands for pseudo-first-order rate constant. The rate increases with the increase in water content of the solvent. A mechanism involving a preequllibrium of an adduct formation between the complex and amine was proposed. The equation derived from the mechanism explained all the experimental results and the preequllibrium constants, rate constants of the rate-determing step along with the activation parameters were evaluated.

Using Monte Carlo (MC) method, we simulate two possible mechanisms of N2O decomposition reaction on a catalyst. One of them is in od agreement with the experiment. On the other hand, we also investigate the nature of the reaction rate oscillation in N2O decomposition. The results show that besides simulating mechanisms of surface reactions, MC method can also be an effective tool to investigate the kinetic behavior of complex reactions.

The changes in photoluminescence and FTIR spectra of porous silicon subjected to oxidation were examined. With the increase of oxidizing duration, the relative amount of the Si-H2 surface species on PS decreases even though the photoluminescence intensity increases. the result suggests that it isn't SiH2 but Si-O and Si-O-Si on the interface of PS play a key role in enhancing the photoluminescence. A complete photoluminescence mechanism should consider the influence of surface state of porous silicon based on the quantum confinement effect model.

A detailed study of the cyclic voltammetry curve of Pt(111) electrode in H2SO4 solution by X-ray photoe1ectron spectroscopy (XPS) and a low energy electron diffraction (LEED) has provided firstly direct evidence that the anomalous features reported originally by Clavilier et al. are associated with the specific adsorption of sulfate anions rather than hydrogen adsorption. The (√3×√3)R30°structure on Pt(111) obtained after electrode emersion on the positive scan at more positive potentials than 0.23V vs. Ag/AgCl appears simultaneously with sharp increase of XPS of O1s and S2p. This implies the relationship between anomalous peak and sulfate anion adsorption on emersed Pt(111 ) electrode.

The luminescence behaviors of 4'-dimethyldrinoflavone derivarive with different structures have been studied in different conditions. Results show that the luminescence behavior depends dramatically on the solvent polarity. The reason is attributed to the different conformations in different solvents. The planar conformation is proved to be favorable to the fluorescence emission. In addition, results of viscosity-dependent luminescence property show that for compound 3 with the rigidized planar structure the luminescence behavior do not depend on the medium viscosity. But, for compound 1 and 2 the fluorescence quantum yields increase with increasing medium viscosity evidently, indicating that the rotation relaxation process of benzene ring in the molecule is very important for the nonradiative decay process of excited molecules of compounds.

In the water-in-oil microemulsion system of Triton X-100, 1-hexanol, cyclohexane and Fe(NO_3)_3 aqueous solution, α－Fe_2O_3 ultrafine particles were prepared by the method of precipitation using NH_3. From transmission electron micrographs the mean diameter of particles is about 3nm. The uniformity of particle is od. These result have been confirmed by the method of Mossbauer spectrum measurement. The conditions of preparation of α－Fe_2O_3 ultrafine particles could be controlled easily and the reaction medium could be used cyclically.

CPZ(O)HCl was synthesized by oxdation of 2-clilorcr-10-(3- dimethylaminopropyl) phenothiazime hydrochloride (CPZHCl) and reacted with CuCl2 to produce [CuCl3CPZ(O)H] complex. The properties of electrochemical of [CuCl3CPZ(O)H] were studies by cyclic voltammetry and conductivity method. The reaction of [CuCl3CPZ(O)H] complex on GC electrode shows single electron reaction and order of magnitude of k 10-4cm.s-1. Molal conductivities of [Cu(Ⅱ)Cl3CPZ(O)H] and CPZ(O)HCl are 220-122S.cm2 .mol-1 and 150-48S'cm2 .mol-1.

The heat of dilution of aqueous solution of the chloride(KCl, NaCl, MgCl2,CaCl2) and sulfate (Na2SO4, K2SO4, MgSO4) of Salt Lakes were measured over a concentration range of 0.05-2.1mol•kg-1 at 298.15K. The data were extrapolated to infinite dilution by use of the Debye-Huckel limition law to obtain relative apparent molal enthalpies (ФLi). The enthalpies of dilution were calculated using the ion interaction model of Pitzer. The experimental enthalpies (△He) were compared with calculated values (△Hc)of dilution.