Mixed solld solutions magnesium-alumina spinel catalyst, MgAl_2O_4·xAl_2O_3·yM (01, the activity decreases which was due to M and spinel coexist in the catalyst. The results of reduction-oxidation (red-ox) cycle tests showed that introducing rare earth cerium to spinel could improve the de-SO_x activity. Of all the catalysts, 0.1 Ce/MgAl_2O_4·M is promising catalyst which has the highest activity. 30% propane as reducing gas is superior to 30% H_2.

The structural parameters of microemulstions composed of P507(K)-alcohol(pentanol, hexanol, iso-pentanol,2-ethyl butanol-1) were calculated based on sphere model and dilution method. The structural parameters include irmer water radius R_w, effective radius of particle R_e, length of interface l, average aggergation number n, total number of particles N_d and total interfacial area of dispersed phase A_d. The results show that R_w has linear relationship with ω (the molax ratio of water to surfactant). According to the intercept, the water solvation thickness of the polar head of P507(K) was calculated to be about 0.58 nm. The maximum numbers of water molecules associating with K~+ in pentanol, hexanol, isopentanol and 2-ethyl butanol-1 containing microemulsions were estimated to be about 5.83, 5.31, 4.95 and 4.28, respectively.

The synthetic reaction, CH_2O+CH_2 (~1A)=C_2H_4O, has been studied by means of ab initio method at the MP4/6-31*//RHF/6-31G* level. The results indicate that the reaction proceeds in two steps. The first step involves the formation of molecular complex(MC). In this step, the energy of the reaction system descends and there is no potential barrier. The second step is the rearrangement of MC to oxirane with potential barrier of 36.99 kJ·mol~(-1); this step is the rate control step for the overall reaction. The thermody-namic and kinetic properties of the synthetic reaction are calculated and discussed. This synthetic reaction might be a new pathway for the synthesis of oxirane.

The photo-induced electron transfer and photochemical of processes phenol and its derivatives on the surface of superfine titanium dioxide colloid particles were studied. It was demonstrated that phenol was more ready to degradate on colloid surface in basic solution. The main degradation products are hydrogen atom and benzene-oxyl radical. The hydroxyl radical of the system was formed from superoxide radical, and not from hydroxide anion. The mechanisms of the photo-induced electron transfer and photochemical reactions were discussed.

Clinopyroxene NaAlSi_2O_6 was synthesized under varying pressures of 3.0-5.0 GPa and at the temperature range of 1150-1750 ℃, for periods of 1-480 min. The glass material was completely transformed into homogeneous penetrating fibrous texture of clinopyroxene NaAlSi_2O_6 when the crystallization was carried out on the optimum condition beyond 4.0 GPa, 1450 ℃, and 45 min . The microstructure of synthetic clinopyroxene NaAlSi_2O_6 was very similiar with that of natural one. Penetrating fibrous grains of the clinopyroxene were highly ordered when the sample was synthesized at above optimun crystalline condition.
The six-fold coordination of the Al~(3+) in the presence of Si~(4+) in clinopyroxene NaAlSi_2O_6 was transformed into four-fold coordination of the Al~(3+) in both nepheline NaAlSiO_4 and albite NaAlSi_3O_8 after it was treated at 1.013×10~5 Pa and 1173 K for 24 hrs. The other preconceived physical and chemical properties of synthetic clinopyroxene was highly consistent with those of the natural sample. The clinopyroxene doped with Cr~(3+), NaAlSi_2O_6: Cr~(3+) (0.5—1.0wt%), which was synthesized beyond the optimum crystalline condition, was of brightness and, hardnes, compact, emerald, translucence.

In this work, a new kind of 2-pyrazoline compound with azastilbene on position 5 has been synthesized. The photoinduced cis-trans isomerization and its mechanism have also been studied. Results indicate that the rate for the photoisomerization reaction of the title compound depends strongly on the polarity of solvents used, and the photoisomerization reaction led to increase of the fluorescence intensity of this compound with increase of irradiation duration.

The effect of Li content in a series of multicomponent oxides Li_xLa_(0.5)Ti_(0.5) for methane oxidative coupling has been studied. The catalytic activities of LiLa_(0.5)Ti_(0.5) catalyst befroe and after washing with boiling water have been compared. The surface and bulk structure of the catalysts were characterized by means of XRD、XPS、IR、BET and so on. The results clearly indicated that the role of Li on the surface is to decrease the sruface area of the catalysts and to cover the deep oxidative active sites thus increasing the C_2 selectivity. However, the role of lithium in the bulk is to produce active phase LaTi_(1-y)Li_yO_(3-λ) in which the defect clusters Li~+-O~--Ti~(3+) act as the active sites for methane oxidative coupling.

In this paper, the effects of calcination temperatures (350-1000 ℃) and metal loadings (5-15% Cu) on copper species of Cu/γ-Al_2O_3 catalysts are studied by means of XRD and EXAFS. For the catalysts, high dispersion state of the copper species could occur at calcination temperature below 700 ℃. The Cu-O coordination peaks at close to 0.16 nm were fitted according to Cu~(2+) taking octahedral (Oh) and tetrahedral (Td) sites. The results of two coordination shell fitting show that the average oxygen coordination numbers of Cu~(2+) (Oh) baries between 5.1 and 6.0. For 5CuY (Y: 350-700 ℃), the ratio of Cu~(2+) (Oh)/Cu~(2+) (Td) decreases gradually as calcination temperature increases, which means that Cu~(2+) ions in Oh move into Td site, and the coordination distance and average coordination number of Cu~(2+) (Oh) increase, indicating the Cu~(2+) (Oh) diffuse from open distorted Oh environment into symmetry one. As for 5Cu900, high temperature calcination makes Cu~(2+) ions diffusing into support phase, partly forming CuAl_2O_4. The value of Cu~(2+) (Oh)/Cu~(2+) ITd) is the same as that in CuAl_2O_4 at higher temperature (1000 ℃) or high loadings (10, 15% Cu).

The process of the formation of the Ga active site in GaZSM-5 zeolite (prepared by impregnation) and the enhancement of the aromatization activity following successive increasing extent of reduction of Ga species were observed by the IR spectra of pyridme adsorption and pulse microreaction system respectively. The results show that absorbance of the band near 1458 cm~(-1) can be correlated with the aromatization activity and Ga content of GaZSM-5 zeolite, so it can be assigned to a pyridine complex with Ga active site. The effect of SiO_2/Al_2O_3 ratio on the formation of Ga active site was also studied. It was found that the sample with lower SiO_2/Al_2O_3 ratio could form more Ga active sites. After measuring the aromatzation activity by pulse microreaction and determining the valence state of Ga sites by TPR, the authors suggest that both the high and the low valence Ga active sites can play the role of the active sites in C_3H_8 aromatization.

Cu-ZSM-5 type molecular sieves were synthesized hydrothermally in weak acid medium in the presence of F~- ions. The structures of these samples were investigated. Increasing the amount of copper in synthesized samples the unit cell volumes of Cu-ZSM-5 zeolites increase, while the adsorption peaks of Cu-ZSM-5 shift to lower wavenumbers. These facts and the results of the electron probe micrograph and XPS analyese indicate that copper was introduced into the framework of molecular sieve.

The electrochemical behavior and the mechanism of methyl orange on tin oxide film electrode were studied by thin layer spectroelectrochemistry. The final products of the reduction of methyl orange are N,N-dimethylphenylenediamine and sodium aminophenyl sulfonate. There are two steps of hydrolytic reactions following the oxidation of the electrogenerated N,N-dimethylphenylenediamine in solution.

Pressure composition isotherms, crystal structures and electrochemical capacities of MmB_5 alloy-hydrogen systems have been investigated, where Mm represents La-rich mischmetals and B_5 take a composition of Ni_(3.8)Co_(0.5)Mn_(0.4)Al_(0.3). All these multicomponent alloys belong to CaCu_5-type hexa nal crystal structuxe. The volume of unit cell (or say, the interstitial hole size) becomes larger with increasing of La content and decreasing of Ce content in Mm. The larger interstitial hole leads to a decrease of dissociation pressure of their hydride, hence improves the stability of MmB_5H_6 and the electrochemical capacity of the MmB_5 alloy. The expansion ratio of the MmB_5 for hydrogen absorption was obviously smaller than that of LaNi_5 alloy. For MmB_5 alloy, especially with high content of La in Mm, a lot of properties for the application in MH/Ni battery, such as against pulverization, long cycle lifetime etc can be promoted.

The activation energy of the enzyme-catalyzed reaction for uric acid decreases markedly in the presence of o-phenanthroline, which activates the bioelectrochemicla activity of the polypyrrole uricase electrode. The response current of the enzyme electrodeis independent of the concentration of o-phenanthroline. Based on the experimental results, the mechamsm of the enzyme-catalyzed reaction for uric acid in the presence of o-phenanthroline is presented as follows: E+A→EA, EA+S EAS, EAS→EA+P, where E, A, S and P are the enzyme, activator, substrate and product, respectively. The effects of pH value, potential and the uric acid concentration on the response currents of the uricase electrode have been studied in the presence of o-phenanthroline. In the presence of o-phenanthroline, the response current of the enzyme electrode increase linearly with increasing concentration of uric acid in the region of 0.07 to 0.67 mmol·L~(-1), therefore the polypyrrole uricase electrode which has once lost its activity can be activated and used again to determine the substrate concentration.

The metal phthalocyanines (MPc, M=Fe, Co, Cu) were supported on the surface of silica gel by chemical linking. They could not be washed out with organic solvents such as Py. UV-Vis diffuse reflectance spectra indicated that MPc s were supported on silica gel. ESR result showed that the supported CoPc and FePc could react with O_2 to produce O~-_2, but the supported CuPc could not.

A simple and easy method with high accuracy has been introduced for the determination of hydrogen absorption properties of alloys, such as hydrogen absorption capacity , paressure-composition isotherms and thermodynamic parameters ΔH and ΔS.
The apparatus is described in details. The equilibrium data can be obtained under hydrogen pressure of 16—0.0001 MPa and in the range of temperature -196—+500 ℃.

Electron spin resonance trapping technique with phenyl t-butyl nitrone (PBN) have been used to study the process of electroreduction of p-toluene sulfonamide at mercury electrode. The results showed that the reaction is a free radical one. p-toluene/benzyl radicals formed yia a stage of detaching sulfonamide group have been identified by the hyperfine spectrum of the radical adducts.