An experimental set up was designed to separately test how sedimentation and convection driven flows affect the perikinetic coagulation process in a ground based experiment. The experiment showed that the sedimentation slightly accelerates the coagulation process and weak free convection driven flows do not noticeably contribute to coagulation for 2 μm particles' dispersion.

In this paper, the three dimensional pharmacophore model of two kinds of HCV NS3 serine protease inhibitors was obtained by using the CATALYST software. Although these two kinds of inhibitors possess quite different structures,yet a common pharmacophore model with very od statistical results can be determined. The results uncover that these two kinds of molecules will take the similar pattern when they interact with the receptor. Based on the pharmacophore model, a 3D-QSAR analysis was performed and the model showed od predictive ability (correlation coefficient R=0.89).

Chemically-wet treated silicon substrate was modified with self-assembled monolayer of 3-aminopropyl-trimethylsilane by aqueous phase silanization, giving an ultrasmooth and homogenous surface terminated with amino groups. Colloidal ld nanoparticles (15.7±2.0 nm)were adsorbed on such a surface with a submonolayer coverage and a random particle distribution. Increases in local surface coverage and packing order were induced by capping the assembled ld nanoparticles with alkanthiol molecules in an enthanolic solution.

r-1,c-2, t-3, t-4-1,3-bis(4-biphenyl)-2,4-di(4-pyridyl)cyclobutane (II) was obtained in diluted sulfuric acid by photodimerization reaction. Its structure was determined by X-ray diffraction method. The crystal is monoclinic, space group is P21/n,with a=1.0038(2), b=1.8995(4), c=1.4647(3)nm, β=98.82(3)°, Z=4. The cyclobutane ring of II has puckered conformation. It was found that under short wave UV light II is easy to be photolyzed to reproduce its monomer trans-1-(4-biphenyl)-2-(4-pyridyl)ethene (E-I),and then the new formed E-I transforms to its cis-isomer(Z-I) through trans-cis isomerization. Finally, the equilibrium of isomerization establishes between E-I and Z-I. Photolysis of II or E-I will form the same isomerization mixture.

The complexation between poly(methacrylic acid)(PMAA) and cationically modified polyacrylamide(QCPAM) was investigated by fluorescence anisotropy measurements, fluorescence probe studies and fluorescence quenching techniques. It has been demonstrated that the complexation occurs between pH 2 and 8, and the best conditions for complexation are pH 4 and complex ratio 1:1(PMAA:QCPAM, in monomer unit). In addition, along with the complexation, the conformation of PMAA changed dramatically. The pH and complexation dependences of the conformation of PMAA may find some uses in design and synthesis of “intelligent” polyelectrolyte gels.

Molecular dynamics calculations were performed to monomers and dimers of three kinds of metallothioneins in water solution. For these kinds of metallothioneins, the structure of MT-II in rat liver obtained directly from Protein Data Bank, while other two structures of MT-I and MT-II in rabbit liver were constructed by homology modeling. The results of molecular dynamics showed that these three kinds of MTs possessed relatively high flexibility, which mainly derived from two residues in flexible region. To three kinds of monomer, the calculations results confirmed the view that the dynamics stability of α domain was better than that of β domain. Comparing the coordinates r.m.s, it could be found that the dimers are more stable than the monomers. The main reason is that the conformational space of these residues in the flexible region would be restricted to some extent when the dimers formed.

The surface complex support of V2O5-SiO2(VSiO) was prepared by the method of surface reaction modification. VSiO supported Cu-Ni bimetallic catalysts were made using isovolumic impregnation. Adsorption and reaction of CO2 and CH3OH on catalyst were characterized by IR, TPD, TPSR and micro-reactor techniques. The results show that three active sites exist on Cu-Ni/VSiO catalyst: metal site(Cu-Ni alloy, denoted M), Lewis acid site(Vn+)and Lewis basic site(V=O); horizontally adsorped CO2, formed by shearingly adsorbed CO2 on M in cooperation with the adjacent Vn+, can dissociate into M-CO and V=O at about 138 ℃and methanol dissociated into V-OCH3 and V-OH cooperated with Vn+ and adjacent V=O; the mainly reaction products of the reaction of CO2 and CH3OH on Cu-Ni/VSiO catalyst are DMC (with selectivity over 85%), CH2O, CO and H2O.

Photolysis and photosensition of cyclic-phenylalanine-histidine(cyclic-Phe-His) in aqueous solution were studied using KrF laser flash photolysis (248nm). Photoionization and photodissociation of cyclic-Phe-His in Phe-site occured and the charateristic absorption at 320nm and 410nm have been observed. From changes of the absorption peaks and kinetic analysis, the reaction mechanism of photoionization and photodissociation has been suggested, a series of kinetic parameters have been obtained. Using acetone as a photosensitizer, and N3• as an oxidant by pulse radiolysis method, the induced oxidation of cyclic-Phe-His in aqueous solution has been also reported in this paper, results similar to the photoionization of cyclic-Phe-His have been found.

The relativistic pseudopotential CASSCF/CI calculation has been performed for the ground state (X1Σ+) and a few low-lying excited states (A3Π,B3Σ+,C1Π and D1Σ+) of van der Waals molecule ZnNe. The electronic structure, the potential energy curves and the spectra constants of the states have been obtained. For the ground state (X1Σ+),the equilibrium distance(Re=0.43nm) obtained in this paper is in well agreement with the corresponding experimental value (0.43nm) and the dissociation energy (De=79cm-1) is od comparing with the experimental value (23.4cm-1). For the other states (A3Π, B3Σ+, C1Π and D1Σ+), the Re is 0.425, 0.55, 0.40 and 0.55nm, respectively and the De is 74.6,unstable,232.53 and 129.45cm-1 respectively. We think that these values are reasonable comparing with those of the similar molecule such as CdNe, although the corresponding experimental values are unavailable. The potential curves show that the wells of Πstates are deeper than those of the corresponding Σ states, and the bond lengths of Π states are shorter than those of the corresponding Σ states. From the electronic structure analysis, the bonds of ZnNe for the low-lying states can be described as the static charge attractive force which stems from atomic charge transfer produced by atomic orbital overlaps as well as van der Waals′force.

The three pathways of [2+2] cycloaddition of ketenimine with imine have been studied at HF/6-31G** and MP2/6-31G** levels of theory. The results indicate that the energy barriers of pathway (1) and pathway (2) are low. So the two reactions can proceed easily. While the energy barrier of pathway (3) is high, it is difficult to proceed. We explain the mechanisms of the first two pathways by the Frontier Orbital Theory at HF/6-31G** level.

A comparative study on the fluorescence behavior of the chemical modified β-cyclodextrin appended a N,N-dimethylamino-chalcone group (DMAC-CD) and the non-modified β-CD mixed with free dimethylamino-chalcone (DMAC+CD) in alcohol/water mixed solvents have been carried out in this work. The fluorescence data obtained——maximum peak wavelength and emission intensity——indicates that the inclusion behavior of the above-mentioned systems is obviously different in mixed alcohol/water solvents. The solvent-induced multi-component complex formation and dissociation and the effect of polarity and size of alcohol used have been also studied carefully by variation of the fluorescence spectroscopic characters. The result indicates that the self-inclusion complex of DMAC-CD has a higher stability in mixed alcohol/water solvents than that in the DMAC +β-CD system. The obtained results and the observed phenomena have been discussed in details.

Canonical ensemble(NVT) Monte Carlo simulations have been carried out to get the chemical potentials of the mixture of nitrogen and benzene by the Widom test particle method. The Lennard-Jones potential model is adopted for the description of interactions between nitrogen and benzene molecules, respectively. The Metropolis sampling method and periodic boundary condition were used in the simulation. The polynomial approximation expressions of the reduced chemical potentials of benzene and nitrogen varying with the reduced pressure at 300.2K and yB=0.0625 obtained by polynomial fitting are to be used in the adsorptive simulation of this mixture.

The electrochemical behavior of self-assembled n-dodecanethiol monolayer and n-dodecanethiol/phosphatidylcholine hybrid bilayer modified HMDE in different concentration of Fe(CN)63-/4- solutions has been studied by using cyclic voltammetry and electrochemical impedance spectroscopy measurements. The equivalent circuit of different system have been put forward. We also calculate the normal electron tunneling rate constant k0 and the apparent thickness d of the membrane.

Electrochemical behavior of aqueous sodium sulfide solution at graphite anode, under the condition of different concentrations of Na2S and different temperatures, has been investigated by cyclic voltammetry and chronopotentiometry. The results show that the anodic oxidation of aqueous sulfide solution is irreversible and that polysulfides are formed in rate-determining step of the anodic oxidation. With the increase of electrolytic temperature, potentials corresponding to anodic peaks shift to more negative and those corresponding to cathodic peaks shift to more positive, which indicates that the elevating of temperature is favorable to both oxidation of the sulfide and reduction of products polysulfides or elemental sulfur. Rate constants ks of standard electrode reaction for anodic oxidation of Na2S solution are between 10-4.08～10-4.35cm•s-1 at 70℃. Chronopotentiometric studies show two potential peaks in time-potential curve for a smaller current density value. The potential peaks may result from a self-catalytic effect taking place due to both dissolution of elemental sulfur by S2-,HS-and Sx2-,and transition reactions among polysulfides. The potential peaks disappear with the increasing of anodic current density.

The microemulsion behaviors of europium and sodium salts of naphthenic acid were studied using fluorescence measurements. It was found that 5D0 decay coefficient of europium was 2.08 ms-1 for 100%europium naphthenate, and the coefficients were 1.56, 1.08 and 0.83 ms-1 for 75%, 50% and 20%europium salt of sodium saponified acid respectively. It can be seen that the decay coefficients were also 2.08 ms-1 at the inflexion of curves in the 75%, 50% and 20% europium naphthenate systems with water content. The data reveal that, if there is enough water in the microemulsion, the coordination condition of europium ion in the above microemulsion is similar. It was also found that, for the 75%、60%、50%、40% and 20% europium naphthenate microemulsion systems, the relative fluorescence intensities sharply decrease with the increase of water content and reach a steady values at the same water content.

Six complexes of two series were studied as the catalyst precursors for CO/ethylene copolymerization by using catalytic evaluation method and EXAFS technique. The first series of the complexes has general formular (L)Pd(OCOCF3)2 in which L is DPPPr, DPPBu or DPPEt. The second series of the complexes has general formular (DPPPr)Pd(A)2 in which A-is CF3COO-,P-CH3PhSO3-,Cl-or CH3COO-.The results showed that suitable ligands have relatively strong coordination ability to palladium(Ⅱ) center. Suitable anoins belonging to strong acids, have excellent stability on cationic palladium(Ⅱ),and easy to leave away to give coordination vacant to comonomers.

The structure and the forming process of SO42-/ZrO2-SiO2 catalysts were investigated by TG and DTA. The restraint of silica to the crystallization of the catalysts and the relations of weight loss temperature and loss amount of sulfur oxide bonded to the surface of the catalysts with the contents of zirconia were revealed by experimental results. The forming process of the catalysts was also explored by these techniques, some very important information, which will be useful for understanding the structure and properties of catalysts, were obtained.

The effect of solution composition on the thermostability of aconitase conformation has been studied by differential scanning calorimetry. In order to know the change of the active site of aconitase ,the three salt links in the active site in the pairs Asp 100•His 101,Asp 165•His 147,and G1u 262•His 167 have been studied by increasing temperature and pH of the solution. At pH 7.47,the calorimetric results demonstrated that the three salt links were broken during heat denaturation and followed by deprotonation of the cationic imidazole groups. Consequently, the number of protons bound to the enzyme molecules in native state is higher than that in denatured state. When pH value was raised to 7.89 or higher, the three salt links could not be formed, consequently Tp/pH was equal to zero. The thermodynamic calculation suggested that the fourth or fifth paired residues as Asp 100•His 101 might exist within the aconitase molecules. The experiments showed that the salts NaCl and NaSCN can raise the thermostability of aconitase, but NaSCN is more effective under the same ionic strength. 0.2 mol•L-1 of NaSCN has the highest ability to raise the thermostability. The chelants SA and OP with antitumor activity can not eliminate the Fe-S cluster within the aconitase molecules and almost not influence its thermostability, but considerably change its denaturational enthalpy. The latter suggests that some relationships may exist between the thermodynamic parameter of enzyme denaturation and antitumor activity of the chelants.