The equilirium geometries of heteroatomic cluster Li_3Al have been optimized with the energy gradient method using the double-zeta plus polarization (DZP) basis set.The vertical excited energies and the oscillator strengths have obtained from ab initio configuration interaction method. Transitions to 1~1B_1, 2~1B_1, 5~1A_1 of AlLi_3(C_(2v)) and 1~1B_2, 2~1A_1, 3~1B_2, 3~1A_1 of AlLi_3(D_(3h)→C_(2v)) and 3~1B_2, 1~1B_2, 4~1A_1 of B_2Li_2(C_(2v)) and 1~1B_(2u), 2~1B_(1u), 3~1B_(3u) of Li_2B_2(D_(2h)) have considerable values of oscillator.

According to the relations of pixel signal intensity with the repetition time T_R and echo time T_E in spin-echo single slice imaging pulse sequence, by combining the multi-exponential relaxation procedure of fluids saturated in porous media, tlle information about pore structure of the tested rock is obtained with T_1- and T_2-weighted microimagings. The macro- and micro-pore regions can be distinguished with the information.

The electrochendcal behavior of quercetin among the pH range from 1.5 to 9.5 was studied. In the pH 1.5 to 4.5 and 4.2 to 9.5, two reducing waves were obtained respectively. The former is an irreversible adsorptive wave of molecular quercetin and the latter is an irreversible wave of anodic ion of quercetin.
In the buffer sohition of 0.1 mol·L~(-1) HAc-NaAc, at pH 6.1, the surface catalytic hydrogen waves of the complexes of heavy rare earth ions-quercetin were obtained by single-sweep polarography. The compositions of adsorptive complexes were determined as PE(III):Qu=1:3 by using polarography. In the solution, the compositions of the complexes were determined as RE(III):Qu=1:2 by using photometry. This means that the adsorption of the complex is the pattern of induced adsorption.

This paper proposes a method of testing the free volume models for fluid transport properties by the MD simulation data for square well fluids. Several commouly used free volume models for viscosity and thermal conductivity are evaluated by the method,and the results show that the model proposed by this author is superior to others. Two important conclusions have been derived: a unified model can be applied to both viscosity and thermal conductivity, and the transport properties of liquld and gas (vapor) phases can be correlated simultaniously by the model with unified parameters. The conclusions approached here are of significance to the systems of practical interests.

Solubilities of methane in binary mixtures of water and t-butyl alcohol (TBA) have been measured in the temperature range from 303.15 K to 333.15 K and at pressures up to 6 MPa. The mole fraction of t-butyl alcohol(x_(TBA)) in the mixed solvents varied from 0.0 to 1.0. The dependence of the solubilities on temperature and the composition of the mixed solvents can be explained by clathrate structure in the mixed solvents. The Henry s Law constans, the partial mole volumes of methane in the solvents, and the standard thermodynamic functions (ΔG°, ΔH°, ΔS°) have been calculated and discussed.

The title compound has been synthesised by high-temperature solid state reaction. The crystal structure was determined by single crystal X-ray diffraction method. The crystal belongs to orthorhombic system with space group Pnma, Z=4, α=0.6480(1), b=0.35639(6), c=1.6994(4) nm, V=0.3925(1) nm, D_c=9.37 g·cm~(-3), λ(MoK_α)=0.071069 nm, μ(MoK_α)=514.43 cm~(-1) and F(000)=932. The final R is 0.051 for 706 observations. TaNi_2Te_2 is a new metal-rich layered ternary telluride. In the structure two metal sheets are sandwiched below and above by Te layers, leading to planar tri nal coordination for Ta and tri nal pyramidic coordination for Ni by Te atoms. An important structural character of this compound is that all planar five-member TeNi_4 rings are fused together to form an extended structure, and each Ta atom is sandwiched by two TeNi_4 rings.

The fine control of the pore-opening size of HM zeolite by chemical vapor deposition of Si(OCH_3)_4 has been investigated. Si(OCH_3)_4 can be deposited by reaction with the hydroxyl groups on the zeolie. After calcination in oxygen silica is deposited on the externai surface of the zeolite and produces silica coated HM zeolite (SiHM). The SiHM samples with different amount of silica deposited have been characterized by adsorption experiments and temperature-programmed desorption of NH_3. It has been found that the deposition of silica does not change the acidity of the zeolite internal surface but reduces the pore-opening size. For toluene disproportionation reaction the para-selectivity of the SiHM zeolite catalysts is increased markedly. Under the same reaction conversion the mole fraction p-xylene in the xylene mixture can be raised up to above 0.40 when using SiHM as the reaction catalyst instead of the original HM zeolite. For isomerization of o-xylene the improvement in para-selectivity has not been observed, because the reaction is not mainly controlled by the diffusion of the reaction products.

12-moybdophosphoric acid (PMo_(12)) supported on γ-alumina has been studied by XRD, LRS EPR and titration methods.
The results reveal that as PMo_(12) loading is lower or equal to the monolayer coverage, there is a strong interaction between PMo_(12) and γ-alumina, PMo_(12) is adsorbed by γ-alumina irreversibly and a tetrahedral coordinatha Mo-O-Al species is observed.
Beyond monolayer coverage, the PMo_(12) is dispersed on γ-alumina as primary structure, and a secondary structure PMo_(12) is observed at more higher loading. The EPR results show that the stability of the supported PMo_(12) is lower than that of the unsupported PMo_(12) and the stability of PMo_(12) in the above three diffrent states is not the same. A model of PMo_(12) dispersed on γ-alumina is suggested.

The unimolecular charge separations and neutral loss decompositions of the doubly charged ions [C_7H_7Cl]~(2+), [C_7H_6Cl]~(2+·) and [C_7H_5Cl]~(2+) produced in the ion source by 70 eV electron impact from 3 chloro-toluenes and benzyl chloride isomers were studied using MIKES. The isomerizations for these ions are prior to the decompositions, which make the MIKES for 4 isomers almost identical. The ejections of H depend on whether the parent ion is an odd-electron or an even-electron ion. The even-electron doubly charged ions can only decompose to even-electron fregments by loss of even-number of H atoms, and we called the phenomena as even-electron rule. The structures of the transition states for charge separations are usually different from the structures of neutral molecules. Several structures were discussed based on the values of the kinetic energy releases (T) during the charge separation processes.

Alcohol, presented in the hydrolysis of ferric chloride at elevated temperature, inhibits the phase transformation from β-FeOOH to α-Fe_2O_3, reduces the supersaturation of the precipitated species α-F_2O_3, decreases the number of nucleation and therefore favours the formation of much larger uniform α-F_2O_3 particles. With increasing amount of alcohol, the sizes of particles increase, while the shapes of them change gradually from sphere to cube.

Solubilities of the ternary systems Li~+, K~+/SO_4~(2-)-H_2O (1) and Li~+, Mg~(2+)/SO_4~(2-)-H_2O (2) were investigated by isothermal method at 25 ℃. Physico-chemical properties of solutions, such as density, refractive index, viscosity, conductivity, and pH, were determined. Phase diagram of the system (1) consists of three sollubility branches and three crystallization fields corresponding to K_2SO_4, LiKSO_4, and Li_2SO_4·H_2O. LiKSO_4 is an incongruent compound, and its transition poin is 45.5～46.0 based on our graphical estimate. No solid solution of LiKSO_4 with Li_2SO_4·H_2O was found in the system. System (2) is of a simple eutonic type. Pitzer model of electrolyte solution was used to check the obtained solubilities. Data comparison gives od agreement. Physico-chemical properties of solutions, such as density, refractive index, viscosity, conductivity, pH, and X-ray diffraction, IR spectra, DTA of LiKSO_4 were measured. Two equations were used to correlate density, refractive index with copmposition. Differences between measured and calculated values are less than 0.6% for density, 0.15% for the later.

Forms of surface species in molybdenum-nichel catalyst with high molybdenum loading have been studied by using the techniques of X-ray photoelectron spectroscopy, Laser Raman spectroscopy and temperature programmed reduction. The results indicate that the main species on surfaces of oxidic, reduced, sulfided catalysts are NiMo_xO_y whose structure is analo us to NiMoO_4, molybdates of different valence and metal nichel, molybdenum nickel oxysulfide and molybdenum sulfide respectively. The hydrodesulfurization activity sequence of the above three chemical states is: sulfided form, reduced form>>oxidic form and it is positively related to low temperature oxygen capacity. Metal nickel has been observed on the surface of reduced form. From this, it is proposed that spillover of hydrogen atoms created on metal nickel is one reason for the distinct increase of HDS activity in reduced catalyst. Surface species forms in sulfided, reduced states and HDS activities have been related. The results support the side-on catalytic mechanism proposed by H. Kwart.

The catalysts derived from the reduction of intrazeolite Pt carbonyl clusters [Pt_(12)(CO)_(24)]~(2-)/NaY and [Pt_9(CO)_(18)]~(2-)/NaY were characterized by EXAFS and chemisorption techniques. EXAFS analysis gave R_(Pt-Pt)=0.274 nm, C.N.=4.2 for Pt_(12)/NaY and R_(Pt-Pt)=0.274 nm, C.N.=3.8 for Pt_9/NaY, whil the chemisorption of H_2 and CO gave H/Pt=1.26, CO/Pt=0.69 and H/Pt=1.24, CO/Pt=0.64 for Pt_(12)/NaY and Pt_9/NaY respectively. Compared with the results of Pt/Al_2O_3, it is concluded that highly dispersed Pt/NaY catalysts were derived from the intrazeolite Pt carbonyl clusters. Because of the structureal changes of reduced Pt carbonyl clusters, the recarbonylation of Pt_(12)/NaY and Pt_9/NaY can not regenerate the same Pt carbonyl clusters as their precursors.

The enthalpy of dilution of a solution collaining calcium chloride in aqueousmethanol mixture has been determind with LKB-2107 flow microcalorimeter at 298.15 K. The mole fractions of methanol of the mixed solveds x_a were 0.00, 0.24, 0.45, 0.75, 0.87, 0.91, 0.95 and 1.00 respectively. The eaperimental results were correlated with an extended form of the Debye-Huckel equation. Combining with our former works, the enthalpy of dilution at infinite dilution at 0.5 mol·kg~(-1), -ΔH_D~∞ (m=0.5, x_a), for the systems CaCl_2/H_2O-CH_3OH, —C_2H_5OH. -n-C_3H_7OH were calculated. The results obtained indicated that, -ΔH—D~∞ of the three systems change with compositions of the mixed solvent, x_a and thier maximum values are at about 0.87 to 0.95 mole fractions. -ΔH—D~∞ increase with increasing of carbon atom number of alcohols at the same x_a.

The reactions between sodium iodide, potassium iodide and a series of N-(parasubstituted phenyl) nitrogen-hetero-15-crown-5 were studied by titration calorimetry at 25 ℃ in ethanol. It was found that the aza-crown ethers and the alkali metal ions form 1:1 complexes. The electron-donating substituent on the phenyl ring may enhance the ligation ability of the macrocyclic ligand. It was found that linear thermodynamic function relationships exist in the systems studied.

This paper is devoted to the newest flow perturbation method, is comprised the general theoretical analysis of method. For those interested in fordiate and direct applications, only the final few equation are needed.